linux/fs/ext4/super.c
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   1/*
   2 *  linux/fs/ext4/super.c
   3 *
   4 * Copyright (C) 1992, 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 *
   9 *  from
  10 *
  11 *  linux/fs/minix/inode.c
  12 *
  13 *  Copyright (C) 1991, 1992  Linus Torvalds
  14 *
  15 *  Big-endian to little-endian byte-swapping/bitmaps by
  16 *        David S. Miller (davem@caip.rutgers.edu), 1995
  17 */
  18
  19#include <linux/module.h>
  20#include <linux/string.h>
  21#include <linux/fs.h>
  22#include <linux/time.h>
  23#include <linux/vmalloc.h>
  24#include <linux/jbd2.h>
  25#include <linux/slab.h>
  26#include <linux/init.h>
  27#include <linux/blkdev.h>
  28#include <linux/parser.h>
  29#include <linux/buffer_head.h>
  30#include <linux/exportfs.h>
  31#include <linux/vfs.h>
  32#include <linux/random.h>
  33#include <linux/mount.h>
  34#include <linux/namei.h>
  35#include <linux/quotaops.h>
  36#include <linux/seq_file.h>
  37#include <linux/proc_fs.h>
  38#include <linux/ctype.h>
  39#include <linux/log2.h>
  40#include <linux/crc16.h>
  41#include <linux/cleancache.h>
  42#include <asm/uaccess.h>
  43
  44#include <linux/kthread.h>
  45#include <linux/freezer.h>
  46
  47#include "ext4.h"
  48#include "ext4_extents.h"
  49#include "ext4_jbd2.h"
  50#include "xattr.h"
  51#include "acl.h"
  52#include "mballoc.h"
  53
  54#define CREATE_TRACE_POINTS
  55#include <trace/events/ext4.h>
  56
  57static struct proc_dir_entry *ext4_proc_root;
  58static struct kset *ext4_kset;
  59static struct ext4_lazy_init *ext4_li_info;
  60static struct mutex ext4_li_mtx;
  61static struct ext4_features *ext4_feat;
  62
  63static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  64                             unsigned long journal_devnum);
  65static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  66static int ext4_commit_super(struct super_block *sb, int sync);
  67static void ext4_mark_recovery_complete(struct super_block *sb,
  68                                        struct ext4_super_block *es);
  69static void ext4_clear_journal_err(struct super_block *sb,
  70                                   struct ext4_super_block *es);
  71static int ext4_sync_fs(struct super_block *sb, int wait);
  72static const char *ext4_decode_error(struct super_block *sb, int errno,
  73                                     char nbuf[16]);
  74static int ext4_remount(struct super_block *sb, int *flags, char *data);
  75static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  76static int ext4_unfreeze(struct super_block *sb);
  77static int ext4_freeze(struct super_block *sb);
  78static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  79                       const char *dev_name, void *data);
  80static inline int ext2_feature_set_ok(struct super_block *sb);
  81static inline int ext3_feature_set_ok(struct super_block *sb);
  82static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  83static void ext4_destroy_lazyinit_thread(void);
  84static void ext4_unregister_li_request(struct super_block *sb);
  85static void ext4_clear_request_list(void);
  86
  87#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  88static struct file_system_type ext2_fs_type = {
  89        .owner          = THIS_MODULE,
  90        .name           = "ext2",
  91        .mount          = ext4_mount,
  92        .kill_sb        = kill_block_super,
  93        .fs_flags       = FS_REQUIRES_DEV,
  94};
  95#define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  96#else
  97#define IS_EXT2_SB(sb) (0)
  98#endif
  99
 100
 101#if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 102static struct file_system_type ext3_fs_type = {
 103        .owner          = THIS_MODULE,
 104        .name           = "ext3",
 105        .mount          = ext4_mount,
 106        .kill_sb        = kill_block_super,
 107        .fs_flags       = FS_REQUIRES_DEV,
 108};
 109#define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 110#else
 111#define IS_EXT3_SB(sb) (0)
 112#endif
 113
 114static int ext4_verify_csum_type(struct super_block *sb,
 115                                 struct ext4_super_block *es)
 116{
 117        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 118                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 119                return 1;
 120
 121        return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 122}
 123
 124static __le32 ext4_superblock_csum(struct super_block *sb,
 125                                   struct ext4_super_block *es)
 126{
 127        struct ext4_sb_info *sbi = EXT4_SB(sb);
 128        int offset = offsetof(struct ext4_super_block, s_checksum);
 129        __u32 csum;
 130
 131        csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 132
 133        return cpu_to_le32(csum);
 134}
 135
 136int ext4_superblock_csum_verify(struct super_block *sb,
 137                                struct ext4_super_block *es)
 138{
 139        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 140                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 141                return 1;
 142
 143        return es->s_checksum == ext4_superblock_csum(sb, es);
 144}
 145
 146void ext4_superblock_csum_set(struct super_block *sb)
 147{
 148        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 149
 150        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 151                EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 152                return;
 153
 154        es->s_checksum = ext4_superblock_csum(sb, es);
 155}
 156
 157void *ext4_kvmalloc(size_t size, gfp_t flags)
 158{
 159        void *ret;
 160
 161        ret = kmalloc(size, flags);
 162        if (!ret)
 163                ret = __vmalloc(size, flags, PAGE_KERNEL);
 164        return ret;
 165}
 166
 167void *ext4_kvzalloc(size_t size, gfp_t flags)
 168{
 169        void *ret;
 170
 171        ret = kzalloc(size, flags);
 172        if (!ret)
 173                ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 174        return ret;
 175}
 176
 177void ext4_kvfree(void *ptr)
 178{
 179        if (is_vmalloc_addr(ptr))
 180                vfree(ptr);
 181        else
 182                kfree(ptr);
 183
 184}
 185
 186ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 187                               struct ext4_group_desc *bg)
 188{
 189        return le32_to_cpu(bg->bg_block_bitmap_lo) |
 190                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 191                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 192}
 193
 194ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 195                               struct ext4_group_desc *bg)
 196{
 197        return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 198                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 199                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 200}
 201
 202ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 203                              struct ext4_group_desc *bg)
 204{
 205        return le32_to_cpu(bg->bg_inode_table_lo) |
 206                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 207                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 208}
 209
 210__u32 ext4_free_group_clusters(struct super_block *sb,
 211                               struct ext4_group_desc *bg)
 212{
 213        return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 214                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 215                 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 216}
 217
 218__u32 ext4_free_inodes_count(struct super_block *sb,
 219                              struct ext4_group_desc *bg)
 220{
 221        return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 222                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 223                 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 224}
 225
 226__u32 ext4_used_dirs_count(struct super_block *sb,
 227                              struct ext4_group_desc *bg)
 228{
 229        return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 230                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 231                 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 232}
 233
 234__u32 ext4_itable_unused_count(struct super_block *sb,
 235                              struct ext4_group_desc *bg)
 236{
 237        return le16_to_cpu(bg->bg_itable_unused_lo) |
 238                (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 239                 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 240}
 241
 242void ext4_block_bitmap_set(struct super_block *sb,
 243                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 244{
 245        bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 246        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 247                bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 248}
 249
 250void ext4_inode_bitmap_set(struct super_block *sb,
 251                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 252{
 253        bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 254        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 255                bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 256}
 257
 258void ext4_inode_table_set(struct super_block *sb,
 259                          struct ext4_group_desc *bg, ext4_fsblk_t blk)
 260{
 261        bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 262        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 263                bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 264}
 265
 266void ext4_free_group_clusters_set(struct super_block *sb,
 267                                  struct ext4_group_desc *bg, __u32 count)
 268{
 269        bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 270        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 271                bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 272}
 273
 274void ext4_free_inodes_set(struct super_block *sb,
 275                          struct ext4_group_desc *bg, __u32 count)
 276{
 277        bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 278        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 279                bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 280}
 281
 282void ext4_used_dirs_set(struct super_block *sb,
 283                          struct ext4_group_desc *bg, __u32 count)
 284{
 285        bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 286        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 287                bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 288}
 289
 290void ext4_itable_unused_set(struct super_block *sb,
 291                          struct ext4_group_desc *bg, __u32 count)
 292{
 293        bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 294        if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 295                bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 296}
 297
 298
 299/* Just increment the non-pointer handle value */
 300static handle_t *ext4_get_nojournal(void)
 301{
 302        handle_t *handle = current->journal_info;
 303        unsigned long ref_cnt = (unsigned long)handle;
 304
 305        BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
 306
 307        ref_cnt++;
 308        handle = (handle_t *)ref_cnt;
 309
 310        current->journal_info = handle;
 311        return handle;
 312}
 313
 314
 315/* Decrement the non-pointer handle value */
 316static void ext4_put_nojournal(handle_t *handle)
 317{
 318        unsigned long ref_cnt = (unsigned long)handle;
 319
 320        BUG_ON(ref_cnt == 0);
 321
 322        ref_cnt--;
 323        handle = (handle_t *)ref_cnt;
 324
 325        current->journal_info = handle;
 326}
 327
 328/*
 329 * Wrappers for jbd2_journal_start/end.
 330 */
 331handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 332{
 333        journal_t *journal;
 334
 335        trace_ext4_journal_start(sb, nblocks, _RET_IP_);
 336        if (sb->s_flags & MS_RDONLY)
 337                return ERR_PTR(-EROFS);
 338
 339        WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
 340        journal = EXT4_SB(sb)->s_journal;
 341        if (!journal)
 342                return ext4_get_nojournal();
 343        /*
 344         * Special case here: if the journal has aborted behind our
 345         * backs (eg. EIO in the commit thread), then we still need to
 346         * take the FS itself readonly cleanly.
 347         */
 348        if (is_journal_aborted(journal)) {
 349                ext4_abort(sb, "Detected aborted journal");
 350                return ERR_PTR(-EROFS);
 351        }
 352        return jbd2_journal_start(journal, nblocks);
 353}
 354
 355int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 356{
 357        struct super_block *sb;
 358        int err;
 359        int rc;
 360
 361        if (!ext4_handle_valid(handle)) {
 362                ext4_put_nojournal(handle);
 363                return 0;
 364        }
 365        sb = handle->h_transaction->t_journal->j_private;
 366        err = handle->h_err;
 367        rc = jbd2_journal_stop(handle);
 368
 369        if (!err)
 370                err = rc;
 371        if (err)
 372                __ext4_std_error(sb, where, line, err);
 373        return err;
 374}
 375
 376void ext4_journal_abort_handle(const char *caller, unsigned int line,
 377                               const char *err_fn, struct buffer_head *bh,
 378                               handle_t *handle, int err)
 379{
 380        char nbuf[16];
 381        const char *errstr = ext4_decode_error(NULL, err, nbuf);
 382
 383        BUG_ON(!ext4_handle_valid(handle));
 384
 385        if (bh)
 386                BUFFER_TRACE(bh, "abort");
 387
 388        if (!handle->h_err)
 389                handle->h_err = err;
 390
 391        if (is_handle_aborted(handle))
 392                return;
 393
 394        printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 395               caller, line, errstr, err_fn);
 396
 397        jbd2_journal_abort_handle(handle);
 398}
 399
 400static void __save_error_info(struct super_block *sb, const char *func,
 401                            unsigned int line)
 402{
 403        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 404
 405        EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 406        es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 407        es->s_last_error_time = cpu_to_le32(get_seconds());
 408        strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 409        es->s_last_error_line = cpu_to_le32(line);
 410        if (!es->s_first_error_time) {
 411                es->s_first_error_time = es->s_last_error_time;
 412                strncpy(es->s_first_error_func, func,
 413                        sizeof(es->s_first_error_func));
 414                es->s_first_error_line = cpu_to_le32(line);
 415                es->s_first_error_ino = es->s_last_error_ino;
 416                es->s_first_error_block = es->s_last_error_block;
 417        }
 418        /*
 419         * Start the daily error reporting function if it hasn't been
 420         * started already
 421         */
 422        if (!es->s_error_count)
 423                mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 424        le32_add_cpu(&es->s_error_count, 1);
 425}
 426
 427static void save_error_info(struct super_block *sb, const char *func,
 428                            unsigned int line)
 429{
 430        __save_error_info(sb, func, line);
 431        ext4_commit_super(sb, 1);
 432}
 433
 434/*
 435 * The del_gendisk() function uninitializes the disk-specific data
 436 * structures, including the bdi structure, without telling anyone
 437 * else.  Once this happens, any attempt to call mark_buffer_dirty()
 438 * (for example, by ext4_commit_super), will cause a kernel OOPS.
 439 * This is a kludge to prevent these oops until we can put in a proper
 440 * hook in del_gendisk() to inform the VFS and file system layers.
 441 */
 442static int block_device_ejected(struct super_block *sb)
 443{
 444        struct inode *bd_inode = sb->s_bdev->bd_inode;
 445        struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
 446
 447        return bdi->dev == NULL;
 448}
 449
 450static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 451{
 452        struct super_block              *sb = journal->j_private;
 453        struct ext4_sb_info             *sbi = EXT4_SB(sb);
 454        int                             error = is_journal_aborted(journal);
 455        struct ext4_journal_cb_entry    *jce, *tmp;
 456
 457        spin_lock(&sbi->s_md_lock);
 458        list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
 459                list_del_init(&jce->jce_list);
 460                spin_unlock(&sbi->s_md_lock);
 461                jce->jce_func(sb, jce, error);
 462                spin_lock(&sbi->s_md_lock);
 463        }
 464        spin_unlock(&sbi->s_md_lock);
 465}
 466
 467/* Deal with the reporting of failure conditions on a filesystem such as
 468 * inconsistencies detected or read IO failures.
 469 *
 470 * On ext2, we can store the error state of the filesystem in the
 471 * superblock.  That is not possible on ext4, because we may have other
 472 * write ordering constraints on the superblock which prevent us from
 473 * writing it out straight away; and given that the journal is about to
 474 * be aborted, we can't rely on the current, or future, transactions to
 475 * write out the superblock safely.
 476 *
 477 * We'll just use the jbd2_journal_abort() error code to record an error in
 478 * the journal instead.  On recovery, the journal will complain about
 479 * that error until we've noted it down and cleared it.
 480 */
 481
 482static void ext4_handle_error(struct super_block *sb)
 483{
 484        if (sb->s_flags & MS_RDONLY)
 485                return;
 486
 487        if (!test_opt(sb, ERRORS_CONT)) {
 488                journal_t *journal = EXT4_SB(sb)->s_journal;
 489
 490                EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 491                if (journal)
 492                        jbd2_journal_abort(journal, -EIO);
 493        }
 494        if (test_opt(sb, ERRORS_RO)) {
 495                ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 496                sb->s_flags |= MS_RDONLY;
 497        }
 498        if (test_opt(sb, ERRORS_PANIC))
 499                panic("EXT4-fs (device %s): panic forced after error\n",
 500                        sb->s_id);
 501}
 502
 503void __ext4_error(struct super_block *sb, const char *function,
 504                  unsigned int line, const char *fmt, ...)
 505{
 506        struct va_format vaf;
 507        va_list args;
 508
 509        va_start(args, fmt);
 510        vaf.fmt = fmt;
 511        vaf.va = &args;
 512        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 513               sb->s_id, function, line, current->comm, &vaf);
 514        va_end(args);
 515        save_error_info(sb, function, line);
 516
 517        ext4_handle_error(sb);
 518}
 519
 520void ext4_error_inode(struct inode *inode, const char *function,
 521                      unsigned int line, ext4_fsblk_t block,
 522                      const char *fmt, ...)
 523{
 524        va_list args;
 525        struct va_format vaf;
 526        struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 527
 528        es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 529        es->s_last_error_block = cpu_to_le64(block);
 530        save_error_info(inode->i_sb, function, line);
 531        va_start(args, fmt);
 532        vaf.fmt = fmt;
 533        vaf.va = &args;
 534        if (block)
 535                printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 536                       "inode #%lu: block %llu: comm %s: %pV\n",
 537                       inode->i_sb->s_id, function, line, inode->i_ino,
 538                       block, current->comm, &vaf);
 539        else
 540                printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 541                       "inode #%lu: comm %s: %pV\n",
 542                       inode->i_sb->s_id, function, line, inode->i_ino,
 543                       current->comm, &vaf);
 544        va_end(args);
 545
 546        ext4_handle_error(inode->i_sb);
 547}
 548
 549void ext4_error_file(struct file *file, const char *function,
 550                     unsigned int line, ext4_fsblk_t block,
 551                     const char *fmt, ...)
 552{
 553        va_list args;
 554        struct va_format vaf;
 555        struct ext4_super_block *es;
 556        struct inode *inode = file->f_dentry->d_inode;
 557        char pathname[80], *path;
 558
 559        es = EXT4_SB(inode->i_sb)->s_es;
 560        es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 561        save_error_info(inode->i_sb, function, line);
 562        path = d_path(&(file->f_path), pathname, sizeof(pathname));
 563        if (IS_ERR(path))
 564                path = "(unknown)";
 565        va_start(args, fmt);
 566        vaf.fmt = fmt;
 567        vaf.va = &args;
 568        if (block)
 569                printk(KERN_CRIT
 570                       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 571                       "block %llu: comm %s: path %s: %pV\n",
 572                       inode->i_sb->s_id, function, line, inode->i_ino,
 573                       block, current->comm, path, &vaf);
 574        else
 575                printk(KERN_CRIT
 576                       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 577                       "comm %s: path %s: %pV\n",
 578                       inode->i_sb->s_id, function, line, inode->i_ino,
 579                       current->comm, path, &vaf);
 580        va_end(args);
 581
 582        ext4_handle_error(inode->i_sb);
 583}
 584
 585static const char *ext4_decode_error(struct super_block *sb, int errno,
 586                                     char nbuf[16])
 587{
 588        char *errstr = NULL;
 589
 590        switch (errno) {
 591        case -EIO:
 592                errstr = "IO failure";
 593                break;
 594        case -ENOMEM:
 595                errstr = "Out of memory";
 596                break;
 597        case -EROFS:
 598                if (!sb || (EXT4_SB(sb)->s_journal &&
 599                            EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 600                        errstr = "Journal has aborted";
 601                else
 602                        errstr = "Readonly filesystem";
 603                break;
 604        default:
 605                /* If the caller passed in an extra buffer for unknown
 606                 * errors, textualise them now.  Else we just return
 607                 * NULL. */
 608                if (nbuf) {
 609                        /* Check for truncated error codes... */
 610                        if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 611                                errstr = nbuf;
 612                }
 613                break;
 614        }
 615
 616        return errstr;
 617}
 618
 619/* __ext4_std_error decodes expected errors from journaling functions
 620 * automatically and invokes the appropriate error response.  */
 621
 622void __ext4_std_error(struct super_block *sb, const char *function,
 623                      unsigned int line, int errno)
 624{
 625        char nbuf[16];
 626        const char *errstr;
 627
 628        /* Special case: if the error is EROFS, and we're not already
 629         * inside a transaction, then there's really no point in logging
 630         * an error. */
 631        if (errno == -EROFS && journal_current_handle() == NULL &&
 632            (sb->s_flags & MS_RDONLY))
 633                return;
 634
 635        errstr = ext4_decode_error(sb, errno, nbuf);
 636        printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 637               sb->s_id, function, line, errstr);
 638        save_error_info(sb, function, line);
 639
 640        ext4_handle_error(sb);
 641}
 642
 643/*
 644 * ext4_abort is a much stronger failure handler than ext4_error.  The
 645 * abort function may be used to deal with unrecoverable failures such
 646 * as journal IO errors or ENOMEM at a critical moment in log management.
 647 *
 648 * We unconditionally force the filesystem into an ABORT|READONLY state,
 649 * unless the error response on the fs has been set to panic in which
 650 * case we take the easy way out and panic immediately.
 651 */
 652
 653void __ext4_abort(struct super_block *sb, const char *function,
 654                unsigned int line, const char *fmt, ...)
 655{
 656        va_list args;
 657
 658        save_error_info(sb, function, line);
 659        va_start(args, fmt);
 660        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 661               function, line);
 662        vprintk(fmt, args);
 663        printk("\n");
 664        va_end(args);
 665
 666        if ((sb->s_flags & MS_RDONLY) == 0) {
 667                ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 668                sb->s_flags |= MS_RDONLY;
 669                EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 670                if (EXT4_SB(sb)->s_journal)
 671                        jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 672                save_error_info(sb, function, line);
 673        }
 674        if (test_opt(sb, ERRORS_PANIC))
 675                panic("EXT4-fs panic from previous error\n");
 676}
 677
 678void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 679{
 680        struct va_format vaf;
 681        va_list args;
 682
 683        va_start(args, fmt);
 684        vaf.fmt = fmt;
 685        vaf.va = &args;
 686        printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 687        va_end(args);
 688}
 689
 690void __ext4_warning(struct super_block *sb, const char *function,
 691                    unsigned int line, const char *fmt, ...)
 692{
 693        struct va_format vaf;
 694        va_list args;
 695
 696        va_start(args, fmt);
 697        vaf.fmt = fmt;
 698        vaf.va = &args;
 699        printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 700               sb->s_id, function, line, &vaf);
 701        va_end(args);
 702}
 703
 704void __ext4_grp_locked_error(const char *function, unsigned int line,
 705                             struct super_block *sb, ext4_group_t grp,
 706                             unsigned long ino, ext4_fsblk_t block,
 707                             const char *fmt, ...)
 708__releases(bitlock)
 709__acquires(bitlock)
 710{
 711        struct va_format vaf;
 712        va_list args;
 713        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 714
 715        es->s_last_error_ino = cpu_to_le32(ino);
 716        es->s_last_error_block = cpu_to_le64(block);
 717        __save_error_info(sb, function, line);
 718
 719        va_start(args, fmt);
 720
 721        vaf.fmt = fmt;
 722        vaf.va = &args;
 723        printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 724               sb->s_id, function, line, grp);
 725        if (ino)
 726                printk(KERN_CONT "inode %lu: ", ino);
 727        if (block)
 728                printk(KERN_CONT "block %llu:", (unsigned long long) block);
 729        printk(KERN_CONT "%pV\n", &vaf);
 730        va_end(args);
 731
 732        if (test_opt(sb, ERRORS_CONT)) {
 733                ext4_commit_super(sb, 0);
 734                return;
 735        }
 736
 737        ext4_unlock_group(sb, grp);
 738        ext4_handle_error(sb);
 739        /*
 740         * We only get here in the ERRORS_RO case; relocking the group
 741         * may be dangerous, but nothing bad will happen since the
 742         * filesystem will have already been marked read/only and the
 743         * journal has been aborted.  We return 1 as a hint to callers
 744         * who might what to use the return value from
 745         * ext4_grp_locked_error() to distinguish between the
 746         * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 747         * aggressively from the ext4 function in question, with a
 748         * more appropriate error code.
 749         */
 750        ext4_lock_group(sb, grp);
 751        return;
 752}
 753
 754void ext4_update_dynamic_rev(struct super_block *sb)
 755{
 756        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 757
 758        if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 759                return;
 760
 761        ext4_warning(sb,
 762                     "updating to rev %d because of new feature flag, "
 763                     "running e2fsck is recommended",
 764                     EXT4_DYNAMIC_REV);
 765
 766        es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 767        es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 768        es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 769        /* leave es->s_feature_*compat flags alone */
 770        /* es->s_uuid will be set by e2fsck if empty */
 771
 772        /*
 773         * The rest of the superblock fields should be zero, and if not it
 774         * means they are likely already in use, so leave them alone.  We
 775         * can leave it up to e2fsck to clean up any inconsistencies there.
 776         */
 777}
 778
 779/*
 780 * Open the external journal device
 781 */
 782static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 783{
 784        struct block_device *bdev;
 785        char b[BDEVNAME_SIZE];
 786
 787        bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 788        if (IS_ERR(bdev))
 789                goto fail;
 790        return bdev;
 791
 792fail:
 793        ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 794                        __bdevname(dev, b), PTR_ERR(bdev));
 795        return NULL;
 796}
 797
 798/*
 799 * Release the journal device
 800 */
 801static int ext4_blkdev_put(struct block_device *bdev)
 802{
 803        return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 804}
 805
 806static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 807{
 808        struct block_device *bdev;
 809        int ret = -ENODEV;
 810
 811        bdev = sbi->journal_bdev;
 812        if (bdev) {
 813                ret = ext4_blkdev_put(bdev);
 814                sbi->journal_bdev = NULL;
 815        }
 816        return ret;
 817}
 818
 819static inline struct inode *orphan_list_entry(struct list_head *l)
 820{
 821        return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 822}
 823
 824static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 825{
 826        struct list_head *l;
 827
 828        ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 829                 le32_to_cpu(sbi->s_es->s_last_orphan));
 830
 831        printk(KERN_ERR "sb_info orphan list:\n");
 832        list_for_each(l, &sbi->s_orphan) {
 833                struct inode *inode = orphan_list_entry(l);
 834                printk(KERN_ERR "  "
 835                       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 836                       inode->i_sb->s_id, inode->i_ino, inode,
 837                       inode->i_mode, inode->i_nlink,
 838                       NEXT_ORPHAN(inode));
 839        }
 840}
 841
 842static void ext4_put_super(struct super_block *sb)
 843{
 844        struct ext4_sb_info *sbi = EXT4_SB(sb);
 845        struct ext4_super_block *es = sbi->s_es;
 846        int i, err;
 847
 848        ext4_unregister_li_request(sb);
 849        dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 850
 851        flush_workqueue(sbi->dio_unwritten_wq);
 852        destroy_workqueue(sbi->dio_unwritten_wq);
 853
 854        if (sbi->s_journal) {
 855                err = jbd2_journal_destroy(sbi->s_journal);
 856                sbi->s_journal = NULL;
 857                if (err < 0)
 858                        ext4_abort(sb, "Couldn't clean up the journal");
 859        }
 860
 861        del_timer(&sbi->s_err_report);
 862        ext4_release_system_zone(sb);
 863        ext4_mb_release(sb);
 864        ext4_ext_release(sb);
 865        ext4_xattr_put_super(sb);
 866
 867        if (!(sb->s_flags & MS_RDONLY)) {
 868                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 869                es->s_state = cpu_to_le16(sbi->s_mount_state);
 870        }
 871        if (!(sb->s_flags & MS_RDONLY))
 872                ext4_commit_super(sb, 1);
 873
 874        if (sbi->s_proc) {
 875                remove_proc_entry("options", sbi->s_proc);
 876                remove_proc_entry(sb->s_id, ext4_proc_root);
 877        }
 878        kobject_del(&sbi->s_kobj);
 879
 880        for (i = 0; i < sbi->s_gdb_count; i++)
 881                brelse(sbi->s_group_desc[i]);
 882        ext4_kvfree(sbi->s_group_desc);
 883        ext4_kvfree(sbi->s_flex_groups);
 884        percpu_counter_destroy(&sbi->s_freeclusters_counter);
 885        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 886        percpu_counter_destroy(&sbi->s_dirs_counter);
 887        percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 888        brelse(sbi->s_sbh);
 889#ifdef CONFIG_QUOTA
 890        for (i = 0; i < MAXQUOTAS; i++)
 891                kfree(sbi->s_qf_names[i]);
 892#endif
 893
 894        /* Debugging code just in case the in-memory inode orphan list
 895         * isn't empty.  The on-disk one can be non-empty if we've
 896         * detected an error and taken the fs readonly, but the
 897         * in-memory list had better be clean by this point. */
 898        if (!list_empty(&sbi->s_orphan))
 899                dump_orphan_list(sb, sbi);
 900        J_ASSERT(list_empty(&sbi->s_orphan));
 901
 902        invalidate_bdev(sb->s_bdev);
 903        if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 904                /*
 905                 * Invalidate the journal device's buffers.  We don't want them
 906                 * floating about in memory - the physical journal device may
 907                 * hotswapped, and it breaks the `ro-after' testing code.
 908                 */
 909                sync_blockdev(sbi->journal_bdev);
 910                invalidate_bdev(sbi->journal_bdev);
 911                ext4_blkdev_remove(sbi);
 912        }
 913        if (sbi->s_mmp_tsk)
 914                kthread_stop(sbi->s_mmp_tsk);
 915        sb->s_fs_info = NULL;
 916        /*
 917         * Now that we are completely done shutting down the
 918         * superblock, we need to actually destroy the kobject.
 919         */
 920        kobject_put(&sbi->s_kobj);
 921        wait_for_completion(&sbi->s_kobj_unregister);
 922        if (sbi->s_chksum_driver)
 923                crypto_free_shash(sbi->s_chksum_driver);
 924        kfree(sbi->s_blockgroup_lock);
 925        kfree(sbi);
 926}
 927
 928static struct kmem_cache *ext4_inode_cachep;
 929
 930/*
 931 * Called inside transaction, so use GFP_NOFS
 932 */
 933static struct inode *ext4_alloc_inode(struct super_block *sb)
 934{
 935        struct ext4_inode_info *ei;
 936
 937        ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 938        if (!ei)
 939                return NULL;
 940
 941        ei->vfs_inode.i_version = 1;
 942        ei->vfs_inode.i_data.writeback_index = 0;
 943        memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 944        INIT_LIST_HEAD(&ei->i_prealloc_list);
 945        spin_lock_init(&ei->i_prealloc_lock);
 946        ei->i_reserved_data_blocks = 0;
 947        ei->i_reserved_meta_blocks = 0;
 948        ei->i_allocated_meta_blocks = 0;
 949        ei->i_da_metadata_calc_len = 0;
 950        ei->i_da_metadata_calc_last_lblock = 0;
 951        spin_lock_init(&(ei->i_block_reservation_lock));
 952#ifdef CONFIG_QUOTA
 953        ei->i_reserved_quota = 0;
 954#endif
 955        ei->jinode = NULL;
 956        INIT_LIST_HEAD(&ei->i_completed_io_list);
 957        spin_lock_init(&ei->i_completed_io_lock);
 958        ei->i_sync_tid = 0;
 959        ei->i_datasync_tid = 0;
 960        atomic_set(&ei->i_ioend_count, 0);
 961        atomic_set(&ei->i_unwritten, 0);
 962
 963        return &ei->vfs_inode;
 964}
 965
 966static int ext4_drop_inode(struct inode *inode)
 967{
 968        int drop = generic_drop_inode(inode);
 969
 970        trace_ext4_drop_inode(inode, drop);
 971        return drop;
 972}
 973
 974static void ext4_i_callback(struct rcu_head *head)
 975{
 976        struct inode *inode = container_of(head, struct inode, i_rcu);
 977        kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 978}
 979
 980static void ext4_destroy_inode(struct inode *inode)
 981{
 982        if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 983                ext4_msg(inode->i_sb, KERN_ERR,
 984                         "Inode %lu (%p): orphan list check failed!",
 985                         inode->i_ino, EXT4_I(inode));
 986                print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 987                                EXT4_I(inode), sizeof(struct ext4_inode_info),
 988                                true);
 989                dump_stack();
 990        }
 991        call_rcu(&inode->i_rcu, ext4_i_callback);
 992}
 993
 994static void init_once(void *foo)
 995{
 996        struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 997
 998        INIT_LIST_HEAD(&ei->i_orphan);
 999#ifdef CONFIG_EXT4_FS_XATTR
1000        init_rwsem(&ei->xattr_sem);
1001#endif
1002        init_rwsem(&ei->i_data_sem);
1003        inode_init_once(&ei->vfs_inode);
1004}
1005
1006static int init_inodecache(void)
1007{
1008        ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1009                                             sizeof(struct ext4_inode_info),
1010                                             0, (SLAB_RECLAIM_ACCOUNT|
1011                                                SLAB_MEM_SPREAD),
1012                                             init_once);
1013        if (ext4_inode_cachep == NULL)
1014                return -ENOMEM;
1015        return 0;
1016}
1017
1018static void destroy_inodecache(void)
1019{
1020        /*
1021         * Make sure all delayed rcu free inodes are flushed before we
1022         * destroy cache.
1023         */
1024        rcu_barrier();
1025        kmem_cache_destroy(ext4_inode_cachep);
1026}
1027
1028void ext4_clear_inode(struct inode *inode)
1029{
1030        invalidate_inode_buffers(inode);
1031        clear_inode(inode);
1032        dquot_drop(inode);
1033        ext4_discard_preallocations(inode);
1034        if (EXT4_I(inode)->jinode) {
1035                jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1036                                               EXT4_I(inode)->jinode);
1037                jbd2_free_inode(EXT4_I(inode)->jinode);
1038                EXT4_I(inode)->jinode = NULL;
1039        }
1040}
1041
1042static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1043                                        u64 ino, u32 generation)
1044{
1045        struct inode *inode;
1046
1047        if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1048                return ERR_PTR(-ESTALE);
1049        if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1050                return ERR_PTR(-ESTALE);
1051
1052        /* iget isn't really right if the inode is currently unallocated!!
1053         *
1054         * ext4_read_inode will return a bad_inode if the inode had been
1055         * deleted, so we should be safe.
1056         *
1057         * Currently we don't know the generation for parent directory, so
1058         * a generation of 0 means "accept any"
1059         */
1060        inode = ext4_iget(sb, ino);
1061        if (IS_ERR(inode))
1062                return ERR_CAST(inode);
1063        if (generation && inode->i_generation != generation) {
1064                iput(inode);
1065                return ERR_PTR(-ESTALE);
1066        }
1067
1068        return inode;
1069}
1070
1071static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1072                                        int fh_len, int fh_type)
1073{
1074        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1075                                    ext4_nfs_get_inode);
1076}
1077
1078static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1079                                        int fh_len, int fh_type)
1080{
1081        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1082                                    ext4_nfs_get_inode);
1083}
1084
1085/*
1086 * Try to release metadata pages (indirect blocks, directories) which are
1087 * mapped via the block device.  Since these pages could have journal heads
1088 * which would prevent try_to_free_buffers() from freeing them, we must use
1089 * jbd2 layer's try_to_free_buffers() function to release them.
1090 */
1091static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1092                                 gfp_t wait)
1093{
1094        journal_t *journal = EXT4_SB(sb)->s_journal;
1095
1096        WARN_ON(PageChecked(page));
1097        if (!page_has_buffers(page))
1098                return 0;
1099        if (journal)
1100                return jbd2_journal_try_to_free_buffers(journal, page,
1101                                                        wait & ~__GFP_WAIT);
1102        return try_to_free_buffers(page);
1103}
1104
1105#ifdef CONFIG_QUOTA
1106#define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1107#define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1108
1109static int ext4_write_dquot(struct dquot *dquot);
1110static int ext4_acquire_dquot(struct dquot *dquot);
1111static int ext4_release_dquot(struct dquot *dquot);
1112static int ext4_mark_dquot_dirty(struct dquot *dquot);
1113static int ext4_write_info(struct super_block *sb, int type);
1114static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1115                         struct path *path);
1116static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1117                                 int format_id);
1118static int ext4_quota_off(struct super_block *sb, int type);
1119static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1120static int ext4_quota_on_mount(struct super_block *sb, int type);
1121static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1122                               size_t len, loff_t off);
1123static ssize_t ext4_quota_write(struct super_block *sb, int type,
1124                                const char *data, size_t len, loff_t off);
1125static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1126                             unsigned int flags);
1127static int ext4_enable_quotas(struct super_block *sb);
1128
1129static const struct dquot_operations ext4_quota_operations = {
1130        .get_reserved_space = ext4_get_reserved_space,
1131        .write_dquot    = ext4_write_dquot,
1132        .acquire_dquot  = ext4_acquire_dquot,
1133        .release_dquot  = ext4_release_dquot,
1134        .mark_dirty     = ext4_mark_dquot_dirty,
1135        .write_info     = ext4_write_info,
1136        .alloc_dquot    = dquot_alloc,
1137        .destroy_dquot  = dquot_destroy,
1138};
1139
1140static const struct quotactl_ops ext4_qctl_operations = {
1141        .quota_on       = ext4_quota_on,
1142        .quota_off      = ext4_quota_off,
1143        .quota_sync     = dquot_quota_sync,
1144        .get_info       = dquot_get_dqinfo,
1145        .set_info       = dquot_set_dqinfo,
1146        .get_dqblk      = dquot_get_dqblk,
1147        .set_dqblk      = dquot_set_dqblk
1148};
1149
1150static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1151        .quota_on_meta  = ext4_quota_on_sysfile,
1152        .quota_off      = ext4_quota_off_sysfile,
1153        .quota_sync     = dquot_quota_sync,
1154        .get_info       = dquot_get_dqinfo,
1155        .set_info       = dquot_set_dqinfo,
1156        .get_dqblk      = dquot_get_dqblk,
1157        .set_dqblk      = dquot_set_dqblk
1158};
1159#endif
1160
1161static const struct super_operations ext4_sops = {
1162        .alloc_inode    = ext4_alloc_inode,
1163        .destroy_inode  = ext4_destroy_inode,
1164        .write_inode    = ext4_write_inode,
1165        .dirty_inode    = ext4_dirty_inode,
1166        .drop_inode     = ext4_drop_inode,
1167        .evict_inode    = ext4_evict_inode,
1168        .put_super      = ext4_put_super,
1169        .sync_fs        = ext4_sync_fs,
1170        .freeze_fs      = ext4_freeze,
1171        .unfreeze_fs    = ext4_unfreeze,
1172        .statfs         = ext4_statfs,
1173        .remount_fs     = ext4_remount,
1174        .show_options   = ext4_show_options,
1175#ifdef CONFIG_QUOTA
1176        .quota_read     = ext4_quota_read,
1177        .quota_write    = ext4_quota_write,
1178#endif
1179        .bdev_try_to_free_page = bdev_try_to_free_page,
1180};
1181
1182static const struct super_operations ext4_nojournal_sops = {
1183        .alloc_inode    = ext4_alloc_inode,
1184        .destroy_inode  = ext4_destroy_inode,
1185        .write_inode    = ext4_write_inode,
1186        .dirty_inode    = ext4_dirty_inode,
1187        .drop_inode     = ext4_drop_inode,
1188        .evict_inode    = ext4_evict_inode,
1189        .put_super      = ext4_put_super,
1190        .statfs         = ext4_statfs,
1191        .remount_fs     = ext4_remount,
1192        .show_options   = ext4_show_options,
1193#ifdef CONFIG_QUOTA
1194        .quota_read     = ext4_quota_read,
1195        .quota_write    = ext4_quota_write,
1196#endif
1197        .bdev_try_to_free_page = bdev_try_to_free_page,
1198};
1199
1200static const struct export_operations ext4_export_ops = {
1201        .fh_to_dentry = ext4_fh_to_dentry,
1202        .fh_to_parent = ext4_fh_to_parent,
1203        .get_parent = ext4_get_parent,
1204};
1205
1206enum {
1207        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1208        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1209        Opt_nouid32, Opt_debug, Opt_removed,
1210        Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1211        Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1212        Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1213        Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1214        Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1215        Opt_data_err_abort, Opt_data_err_ignore,
1216        Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1217        Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1218        Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1219        Opt_usrquota, Opt_grpquota, Opt_i_version,
1220        Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1221        Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1222        Opt_inode_readahead_blks, Opt_journal_ioprio,
1223        Opt_dioread_nolock, Opt_dioread_lock,
1224        Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1225        Opt_max_dir_size_kb,
1226};
1227
1228static const match_table_t tokens = {
1229        {Opt_bsd_df, "bsddf"},
1230        {Opt_minix_df, "minixdf"},
1231        {Opt_grpid, "grpid"},
1232        {Opt_grpid, "bsdgroups"},
1233        {Opt_nogrpid, "nogrpid"},
1234        {Opt_nogrpid, "sysvgroups"},
1235        {Opt_resgid, "resgid=%u"},
1236        {Opt_resuid, "resuid=%u"},
1237        {Opt_sb, "sb=%u"},
1238        {Opt_err_cont, "errors=continue"},
1239        {Opt_err_panic, "errors=panic"},
1240        {Opt_err_ro, "errors=remount-ro"},
1241        {Opt_nouid32, "nouid32"},
1242        {Opt_debug, "debug"},
1243        {Opt_removed, "oldalloc"},
1244        {Opt_removed, "orlov"},
1245        {Opt_user_xattr, "user_xattr"},
1246        {Opt_nouser_xattr, "nouser_xattr"},
1247        {Opt_acl, "acl"},
1248        {Opt_noacl, "noacl"},
1249        {Opt_noload, "norecovery"},
1250        {Opt_noload, "noload"},
1251        {Opt_removed, "nobh"},
1252        {Opt_removed, "bh"},
1253        {Opt_commit, "commit=%u"},
1254        {Opt_min_batch_time, "min_batch_time=%u"},
1255        {Opt_max_batch_time, "max_batch_time=%u"},
1256        {Opt_journal_dev, "journal_dev=%u"},
1257        {Opt_journal_checksum, "journal_checksum"},
1258        {Opt_journal_async_commit, "journal_async_commit"},
1259        {Opt_abort, "abort"},
1260        {Opt_data_journal, "data=journal"},
1261        {Opt_data_ordered, "data=ordered"},
1262        {Opt_data_writeback, "data=writeback"},
1263        {Opt_data_err_abort, "data_err=abort"},
1264        {Opt_data_err_ignore, "data_err=ignore"},
1265        {Opt_offusrjquota, "usrjquota="},
1266        {Opt_usrjquota, "usrjquota=%s"},
1267        {Opt_offgrpjquota, "grpjquota="},
1268        {Opt_grpjquota, "grpjquota=%s"},
1269        {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1270        {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1271        {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1272        {Opt_grpquota, "grpquota"},
1273        {Opt_noquota, "noquota"},
1274        {Opt_quota, "quota"},
1275        {Opt_usrquota, "usrquota"},
1276        {Opt_barrier, "barrier=%u"},
1277        {Opt_barrier, "barrier"},
1278        {Opt_nobarrier, "nobarrier"},
1279        {Opt_i_version, "i_version"},
1280        {Opt_stripe, "stripe=%u"},
1281        {Opt_delalloc, "delalloc"},
1282        {Opt_nodelalloc, "nodelalloc"},
1283        {Opt_mblk_io_submit, "mblk_io_submit"},
1284        {Opt_nomblk_io_submit, "nomblk_io_submit"},
1285        {Opt_block_validity, "block_validity"},
1286        {Opt_noblock_validity, "noblock_validity"},
1287        {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1288        {Opt_journal_ioprio, "journal_ioprio=%u"},
1289        {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1290        {Opt_auto_da_alloc, "auto_da_alloc"},
1291        {Opt_noauto_da_alloc, "noauto_da_alloc"},
1292        {Opt_dioread_nolock, "dioread_nolock"},
1293        {Opt_dioread_lock, "dioread_lock"},
1294        {Opt_discard, "discard"},
1295        {Opt_nodiscard, "nodiscard"},
1296        {Opt_init_itable, "init_itable=%u"},
1297        {Opt_init_itable, "init_itable"},
1298        {Opt_noinit_itable, "noinit_itable"},
1299        {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1300        {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1301        {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1302        {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1303        {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1304        {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1305        {Opt_err, NULL},
1306};
1307
1308static ext4_fsblk_t get_sb_block(void **data)
1309{
1310        ext4_fsblk_t    sb_block;
1311        char            *options = (char *) *data;
1312
1313        if (!options || strncmp(options, "sb=", 3) != 0)
1314                return 1;       /* Default location */
1315
1316        options += 3;
1317        /* TODO: use simple_strtoll with >32bit ext4 */
1318        sb_block = simple_strtoul(options, &options, 0);
1319        if (*options && *options != ',') {
1320                printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1321                       (char *) *data);
1322                return 1;
1323        }
1324        if (*options == ',')
1325                options++;
1326        *data = (void *) options;
1327
1328        return sb_block;
1329}
1330
1331#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1332static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1333        "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1334
1335#ifdef CONFIG_QUOTA
1336static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1337{
1338        struct ext4_sb_info *sbi = EXT4_SB(sb);
1339        char *qname;
1340
1341        if (sb_any_quota_loaded(sb) &&
1342                !sbi->s_qf_names[qtype]) {
1343                ext4_msg(sb, KERN_ERR,
1344                        "Cannot change journaled "
1345                        "quota options when quota turned on");
1346                return -1;
1347        }
1348        qname = match_strdup(args);
1349        if (!qname) {
1350                ext4_msg(sb, KERN_ERR,
1351                        "Not enough memory for storing quotafile name");
1352                return -1;
1353        }
1354        if (sbi->s_qf_names[qtype] &&
1355                strcmp(sbi->s_qf_names[qtype], qname)) {
1356                ext4_msg(sb, KERN_ERR,
1357                        "%s quota file already specified", QTYPE2NAME(qtype));
1358                kfree(qname);
1359                return -1;
1360        }
1361        sbi->s_qf_names[qtype] = qname;
1362        if (strchr(sbi->s_qf_names[qtype], '/')) {
1363                ext4_msg(sb, KERN_ERR,
1364                        "quotafile must be on filesystem root");
1365                kfree(sbi->s_qf_names[qtype]);
1366                sbi->s_qf_names[qtype] = NULL;
1367                return -1;
1368        }
1369        set_opt(sb, QUOTA);
1370        return 1;
1371}
1372
1373static int clear_qf_name(struct super_block *sb, int qtype)
1374{
1375
1376        struct ext4_sb_info *sbi = EXT4_SB(sb);
1377
1378        if (sb_any_quota_loaded(sb) &&
1379                sbi->s_qf_names[qtype]) {
1380                ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1381                        " when quota turned on");
1382                return -1;
1383        }
1384        /*
1385         * The space will be released later when all options are confirmed
1386         * to be correct
1387         */
1388        sbi->s_qf_names[qtype] = NULL;
1389        return 1;
1390}
1391#endif
1392
1393#define MOPT_SET        0x0001
1394#define MOPT_CLEAR      0x0002
1395#define MOPT_NOSUPPORT  0x0004
1396#define MOPT_EXPLICIT   0x0008
1397#define MOPT_CLEAR_ERR  0x0010
1398#define MOPT_GTE0       0x0020
1399#ifdef CONFIG_QUOTA
1400#define MOPT_Q          0
1401#define MOPT_QFMT       0x0040
1402#else
1403#define MOPT_Q          MOPT_NOSUPPORT
1404#define MOPT_QFMT       MOPT_NOSUPPORT
1405#endif
1406#define MOPT_DATAJ      0x0080
1407
1408static const struct mount_opts {
1409        int     token;
1410        int     mount_opt;
1411        int     flags;
1412} ext4_mount_opts[] = {
1413        {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1414        {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1415        {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1416        {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1417        {Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1418        {Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1419        {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1420        {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1421        {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1422        {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1423        {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1424        {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1425        {Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1426        {Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1427        {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1428        {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1429                                    EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1430        {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1431        {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1432        {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1433        {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1434        {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1435        {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1436        {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1437        {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1438        {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1439        {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1440        {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1441        {Opt_commit, 0, MOPT_GTE0},
1442        {Opt_max_batch_time, 0, MOPT_GTE0},
1443        {Opt_min_batch_time, 0, MOPT_GTE0},
1444        {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1445        {Opt_init_itable, 0, MOPT_GTE0},
1446        {Opt_stripe, 0, MOPT_GTE0},
1447        {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1448        {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1449        {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1450#ifdef CONFIG_EXT4_FS_XATTR
1451        {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1452        {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1453#else
1454        {Opt_user_xattr, 0, MOPT_NOSUPPORT},
1455        {Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
1456#endif
1457#ifdef CONFIG_EXT4_FS_POSIX_ACL
1458        {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1459        {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1460#else
1461        {Opt_acl, 0, MOPT_NOSUPPORT},
1462        {Opt_noacl, 0, MOPT_NOSUPPORT},
1463#endif
1464        {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1465        {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1466        {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1467        {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1468                                                        MOPT_SET | MOPT_Q},
1469        {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1470                                                        MOPT_SET | MOPT_Q},
1471        {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1472                       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1473        {Opt_usrjquota, 0, MOPT_Q},
1474        {Opt_grpjquota, 0, MOPT_Q},
1475        {Opt_offusrjquota, 0, MOPT_Q},
1476        {Opt_offgrpjquota, 0, MOPT_Q},
1477        {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1478        {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1479        {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1480        {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1481        {Opt_err, 0, 0}
1482};
1483
1484static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1485                            substring_t *args, unsigned long *journal_devnum,
1486                            unsigned int *journal_ioprio, int is_remount)
1487{
1488        struct ext4_sb_info *sbi = EXT4_SB(sb);
1489        const struct mount_opts *m;
1490        kuid_t uid;
1491        kgid_t gid;
1492        int arg = 0;
1493
1494#ifdef CONFIG_QUOTA
1495        if (token == Opt_usrjquota)
1496                return set_qf_name(sb, USRQUOTA, &args[0]);
1497        else if (token == Opt_grpjquota)
1498                return set_qf_name(sb, GRPQUOTA, &args[0]);
1499        else if (token == Opt_offusrjquota)
1500                return clear_qf_name(sb, USRQUOTA);
1501        else if (token == Opt_offgrpjquota)
1502                return clear_qf_name(sb, GRPQUOTA);
1503#endif
1504        if (args->from && match_int(args, &arg))
1505                return -1;
1506        switch (token) {
1507        case Opt_noacl:
1508        case Opt_nouser_xattr:
1509                ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1510                break;
1511        case Opt_sb:
1512                return 1;       /* handled by get_sb_block() */
1513        case Opt_removed:
1514                ext4_msg(sb, KERN_WARNING,
1515                         "Ignoring removed %s option", opt);
1516                return 1;
1517        case Opt_resuid:
1518                uid = make_kuid(current_user_ns(), arg);
1519                if (!uid_valid(uid)) {
1520                        ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1521                        return -1;
1522                }
1523                sbi->s_resuid = uid;
1524                return 1;
1525        case Opt_resgid:
1526                gid = make_kgid(current_user_ns(), arg);
1527                if (!gid_valid(gid)) {
1528                        ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1529                        return -1;
1530                }
1531                sbi->s_resgid = gid;
1532                return 1;
1533        case Opt_abort:
1534                sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1535                return 1;
1536        case Opt_i_version:
1537                sb->s_flags |= MS_I_VERSION;
1538                return 1;
1539        case Opt_journal_dev:
1540                if (is_remount) {
1541                        ext4_msg(sb, KERN_ERR,
1542                                 "Cannot specify journal on remount");
1543                        return -1;
1544                }
1545                *journal_devnum = arg;
1546                return 1;
1547        case Opt_journal_ioprio:
1548                if (arg < 0 || arg > 7)
1549                        return -1;
1550                *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1551                return 1;
1552        }
1553
1554        for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1555                if (token != m->token)
1556                        continue;
1557                if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1558                        return -1;
1559                if (m->flags & MOPT_EXPLICIT)
1560                        set_opt2(sb, EXPLICIT_DELALLOC);
1561                if (m->flags & MOPT_CLEAR_ERR)
1562                        clear_opt(sb, ERRORS_MASK);
1563                if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1564                        ext4_msg(sb, KERN_ERR, "Cannot change quota "
1565                                 "options when quota turned on");
1566                        return -1;
1567                }
1568
1569                if (m->flags & MOPT_NOSUPPORT) {
1570                        ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1571                } else if (token == Opt_commit) {
1572                        if (arg == 0)
1573                                arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1574                        sbi->s_commit_interval = HZ * arg;
1575                } else if (token == Opt_max_batch_time) {
1576                        if (arg == 0)
1577                                arg = EXT4_DEF_MAX_BATCH_TIME;
1578                        sbi->s_max_batch_time = arg;
1579                } else if (token == Opt_min_batch_time) {
1580                        sbi->s_min_batch_time = arg;
1581                } else if (token == Opt_inode_readahead_blks) {
1582                        if (arg > (1 << 30))
1583                                return -1;
1584                        if (arg && !is_power_of_2(arg)) {
1585                                ext4_msg(sb, KERN_ERR,
1586                                         "EXT4-fs: inode_readahead_blks"
1587                                         " must be a power of 2");
1588                                return -1;
1589                        }
1590                        sbi->s_inode_readahead_blks = arg;
1591                } else if (token == Opt_init_itable) {
1592                        set_opt(sb, INIT_INODE_TABLE);
1593                        if (!args->from)
1594                                arg = EXT4_DEF_LI_WAIT_MULT;
1595                        sbi->s_li_wait_mult = arg;
1596                } else if (token == Opt_max_dir_size_kb) {
1597                        sbi->s_max_dir_size_kb = arg;
1598                } else if (token == Opt_stripe) {
1599                        sbi->s_stripe = arg;
1600                } else if (m->flags & MOPT_DATAJ) {
1601                        if (is_remount) {
1602                                if (!sbi->s_journal)
1603                                        ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1604                                else if (test_opt(sb, DATA_FLAGS) !=
1605                                         m->mount_opt) {
1606                                        ext4_msg(sb, KERN_ERR,
1607                                         "Cannot change data mode on remount");
1608                                        return -1;
1609                                }
1610                        } else {
1611                                clear_opt(sb, DATA_FLAGS);
1612                                sbi->s_mount_opt |= m->mount_opt;
1613                        }
1614#ifdef CONFIG_QUOTA
1615                } else if (m->flags & MOPT_QFMT) {
1616                        if (sb_any_quota_loaded(sb) &&
1617                            sbi->s_jquota_fmt != m->mount_opt) {
1618                                ext4_msg(sb, KERN_ERR, "Cannot "
1619                                         "change journaled quota options "
1620                                         "when quota turned on");
1621                                return -1;
1622                        }
1623                        sbi->s_jquota_fmt = m->mount_opt;
1624#endif
1625                } else {
1626                        if (!args->from)
1627                                arg = 1;
1628                        if (m->flags & MOPT_CLEAR)
1629                                arg = !arg;
1630                        else if (unlikely(!(m->flags & MOPT_SET))) {
1631                                ext4_msg(sb, KERN_WARNING,
1632                                         "buggy handling of option %s", opt);
1633                                WARN_ON(1);
1634                                return -1;
1635                        }
1636                        if (arg != 0)
1637                                sbi->s_mount_opt |= m->mount_opt;
1638                        else
1639                                sbi->s_mount_opt &= ~m->mount_opt;
1640                }
1641                return 1;
1642        }
1643        ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1644                 "or missing value", opt);
1645        return -1;
1646}
1647
1648static int parse_options(char *options, struct super_block *sb,
1649                         unsigned long *journal_devnum,
1650                         unsigned int *journal_ioprio,
1651                         int is_remount)
1652{
1653#ifdef CONFIG_QUOTA
1654        struct ext4_sb_info *sbi = EXT4_SB(sb);
1655#endif
1656        char *p;
1657        substring_t args[MAX_OPT_ARGS];
1658        int token;
1659
1660        if (!options)
1661                return 1;
1662
1663        while ((p = strsep(&options, ",")) != NULL) {
1664                if (!*p)
1665                        continue;
1666                /*
1667                 * Initialize args struct so we know whether arg was
1668                 * found; some options take optional arguments.
1669                 */
1670                args[0].to = args[0].from = NULL;
1671                token = match_token(p, tokens, args);
1672                if (handle_mount_opt(sb, p, token, args, journal_devnum,
1673                                     journal_ioprio, is_remount) < 0)
1674                        return 0;
1675        }
1676#ifdef CONFIG_QUOTA
1677        if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1678                if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1679                        clear_opt(sb, USRQUOTA);
1680
1681                if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1682                        clear_opt(sb, GRPQUOTA);
1683
1684                if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1685                        ext4_msg(sb, KERN_ERR, "old and new quota "
1686                                        "format mixing");
1687                        return 0;
1688                }
1689
1690                if (!sbi->s_jquota_fmt) {
1691                        ext4_msg(sb, KERN_ERR, "journaled quota format "
1692                                        "not specified");
1693                        return 0;
1694                }
1695        } else {
1696                if (sbi->s_jquota_fmt) {
1697                        ext4_msg(sb, KERN_ERR, "journaled quota format "
1698                                        "specified with no journaling "
1699                                        "enabled");
1700                        return 0;
1701                }
1702        }
1703#endif
1704        return 1;
1705}
1706
1707static inline void ext4_show_quota_options(struct seq_file *seq,
1708                                           struct super_block *sb)
1709{
1710#if defined(CONFIG_QUOTA)
1711        struct ext4_sb_info *sbi = EXT4_SB(sb);
1712
1713        if (sbi->s_jquota_fmt) {
1714                char *fmtname = "";
1715
1716                switch (sbi->s_jquota_fmt) {
1717                case QFMT_VFS_OLD:
1718                        fmtname = "vfsold";
1719                        break;
1720                case QFMT_VFS_V0:
1721                        fmtname = "vfsv0";
1722                        break;
1723                case QFMT_VFS_V1:
1724                        fmtname = "vfsv1";
1725                        break;
1726                }
1727                seq_printf(seq, ",jqfmt=%s", fmtname);
1728        }
1729
1730        if (sbi->s_qf_names[USRQUOTA])
1731                seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1732
1733        if (sbi->s_qf_names[GRPQUOTA])
1734                seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1735
1736        if (test_opt(sb, USRQUOTA))
1737                seq_puts(seq, ",usrquota");
1738
1739        if (test_opt(sb, GRPQUOTA))
1740                seq_puts(seq, ",grpquota");
1741#endif
1742}
1743
1744static const char *token2str(int token)
1745{
1746        const struct match_token *t;
1747
1748        for (t = tokens; t->token != Opt_err; t++)
1749                if (t->token == token && !strchr(t->pattern, '='))
1750                        break;
1751        return t->pattern;
1752}
1753
1754/*
1755 * Show an option if
1756 *  - it's set to a non-default value OR
1757 *  - if the per-sb default is different from the global default
1758 */
1759static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1760                              int nodefs)
1761{
1762        struct ext4_sb_info *sbi = EXT4_SB(sb);
1763        struct ext4_super_block *es = sbi->s_es;
1764        int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1765        const struct mount_opts *m;
1766        char sep = nodefs ? '\n' : ',';
1767
1768#define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1769#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1770
1771        if (sbi->s_sb_block != 1)
1772                SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1773
1774        for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1775                int want_set = m->flags & MOPT_SET;
1776                if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1777                    (m->flags & MOPT_CLEAR_ERR))
1778                        continue;
1779                if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1780                        continue; /* skip if same as the default */
1781                if ((want_set &&
1782                     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1783                    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1784                        continue; /* select Opt_noFoo vs Opt_Foo */
1785                SEQ_OPTS_PRINT("%s", token2str(m->token));
1786        }
1787
1788        if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1789            le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1790                SEQ_OPTS_PRINT("resuid=%u",
1791                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
1792        if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1793            le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1794                SEQ_OPTS_PRINT("resgid=%u",
1795                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
1796        def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1797        if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1798                SEQ_OPTS_PUTS("errors=remount-ro");
1799        if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1800                SEQ_OPTS_PUTS("errors=continue");
1801        if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1802                SEQ_OPTS_PUTS("errors=panic");
1803        if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1804                SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1805        if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1806                SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1807        if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1808                SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1809        if (sb->s_flags & MS_I_VERSION)
1810                SEQ_OPTS_PUTS("i_version");
1811        if (nodefs || sbi->s_stripe)
1812                SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1813        if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1814                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1815                        SEQ_OPTS_PUTS("data=journal");
1816                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1817                        SEQ_OPTS_PUTS("data=ordered");
1818                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1819                        SEQ_OPTS_PUTS("data=writeback");
1820        }
1821        if (nodefs ||
1822            sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1823                SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1824                               sbi->s_inode_readahead_blks);
1825
1826        if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1827                       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1828                SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1829        if (nodefs || sbi->s_max_dir_size_kb)
1830                SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1831
1832        ext4_show_quota_options(seq, sb);
1833        return 0;
1834}
1835
1836static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1837{
1838        return _ext4_show_options(seq, root->d_sb, 0);
1839}
1840
1841static int options_seq_show(struct seq_file *seq, void *offset)
1842{
1843        struct super_block *sb = seq->private;
1844        int rc;
1845
1846        seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1847        rc = _ext4_show_options(seq, sb, 1);
1848        seq_puts(seq, "\n");
1849        return rc;
1850}
1851
1852static int options_open_fs(struct inode *inode, struct file *file)
1853{
1854        return single_open(file, options_seq_show, PDE(inode)->data);
1855}
1856
1857static const struct file_operations ext4_seq_options_fops = {
1858        .owner = THIS_MODULE,
1859        .open = options_open_fs,
1860        .read = seq_read,
1861        .llseek = seq_lseek,
1862        .release = single_release,
1863};
1864
1865static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1866                            int read_only)
1867{
1868        struct ext4_sb_info *sbi = EXT4_SB(sb);
1869        int res = 0;
1870
1871        if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1872                ext4_msg(sb, KERN_ERR, "revision level too high, "
1873                         "forcing read-only mode");
1874                res = MS_RDONLY;
1875        }
1876        if (read_only)
1877                goto done;
1878        if (!(sbi->s_mount_state & EXT4_VALID_FS))
1879                ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1880                         "running e2fsck is recommended");
1881        else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1882                ext4_msg(sb, KERN_WARNING,
1883                         "warning: mounting fs with errors, "
1884                         "running e2fsck is recommended");
1885        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1886                 le16_to_cpu(es->s_mnt_count) >=
1887                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1888                ext4_msg(sb, KERN_WARNING,
1889                         "warning: maximal mount count reached, "
1890                         "running e2fsck is recommended");
1891        else if (le32_to_cpu(es->s_checkinterval) &&
1892                (le32_to_cpu(es->s_lastcheck) +
1893                        le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1894                ext4_msg(sb, KERN_WARNING,
1895                         "warning: checktime reached, "
1896                         "running e2fsck is recommended");
1897        if (!sbi->s_journal)
1898                es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1899        if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1900                es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1901        le16_add_cpu(&es->s_mnt_count, 1);
1902        es->s_mtime = cpu_to_le32(get_seconds());
1903        ext4_update_dynamic_rev(sb);
1904        if (sbi->s_journal)
1905                EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1906
1907        ext4_commit_super(sb, 1);
1908done:
1909        if (test_opt(sb, DEBUG))
1910                printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1911                                "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1912                        sb->s_blocksize,
1913                        sbi->s_groups_count,
1914                        EXT4_BLOCKS_PER_GROUP(sb),
1915                        EXT4_INODES_PER_GROUP(sb),
1916                        sbi->s_mount_opt, sbi->s_mount_opt2);
1917
1918        cleancache_init_fs(sb);
1919        return res;
1920}
1921
1922int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1923{
1924        struct ext4_sb_info *sbi = EXT4_SB(sb);
1925        struct flex_groups *new_groups;
1926        int size;
1927
1928        if (!sbi->s_log_groups_per_flex)
1929                return 0;
1930
1931        size = ext4_flex_group(sbi, ngroup - 1) + 1;
1932        if (size <= sbi->s_flex_groups_allocated)
1933                return 0;
1934
1935        size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1936        new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1937        if (!new_groups) {
1938                ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1939                         size / (int) sizeof(struct flex_groups));
1940                return -ENOMEM;
1941        }
1942
1943        if (sbi->s_flex_groups) {
1944                memcpy(new_groups, sbi->s_flex_groups,
1945                       (sbi->s_flex_groups_allocated *
1946                        sizeof(struct flex_groups)));
1947                ext4_kvfree(sbi->s_flex_groups);
1948        }
1949        sbi->s_flex_groups = new_groups;
1950        sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1951        return 0;
1952}
1953
1954static int ext4_fill_flex_info(struct super_block *sb)
1955{
1956        struct ext4_sb_info *sbi = EXT4_SB(sb);
1957        struct ext4_group_desc *gdp = NULL;
1958        ext4_group_t flex_group;
1959        unsigned int groups_per_flex = 0;
1960        int i, err;
1961
1962        sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1963        if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1964                sbi->s_log_groups_per_flex = 0;
1965                return 1;
1966        }
1967        groups_per_flex = 1U << sbi->s_log_groups_per_flex;
1968
1969        err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1970        if (err)
1971                goto failed;
1972
1973        for (i = 0; i < sbi->s_groups_count; i++) {
1974                gdp = ext4_get_group_desc(sb, i, NULL);
1975
1976                flex_group = ext4_flex_group(sbi, i);
1977                atomic_add(ext4_free_inodes_count(sb, gdp),
1978                           &sbi->s_flex_groups[flex_group].free_inodes);
1979                atomic_add(ext4_free_group_clusters(sb, gdp),
1980                           &sbi->s_flex_groups[flex_group].free_clusters);
1981                atomic_add(ext4_used_dirs_count(sb, gdp),
1982                           &sbi->s_flex_groups[flex_group].used_dirs);
1983        }
1984
1985        return 1;
1986failed:
1987        return 0;
1988}
1989
1990static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1991                                   struct ext4_group_desc *gdp)
1992{
1993        int offset;
1994        __u16 crc = 0;
1995        __le32 le_group = cpu_to_le32(block_group);
1996
1997        if ((sbi->s_es->s_feature_ro_compat &
1998             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1999                /* Use new metadata_csum algorithm */
2000                __u16 old_csum;
2001                __u32 csum32;
2002
2003                old_csum = gdp->bg_checksum;
2004                gdp->bg_checksum = 0;
2005                csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2006                                     sizeof(le_group));
2007                csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2008                                     sbi->s_desc_size);
2009                gdp->bg_checksum = old_csum;
2010
2011                crc = csum32 & 0xFFFF;
2012                goto out;
2013        }
2014
2015        /* old crc16 code */
2016        offset = offsetof(struct ext4_group_desc, bg_checksum);
2017
2018        crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2019        crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2020        crc = crc16(crc, (__u8 *)gdp, offset);
2021        offset += sizeof(gdp->bg_checksum); /* skip checksum */
2022        /* for checksum of struct ext4_group_desc do the rest...*/
2023        if ((sbi->s_es->s_feature_incompat &
2024             cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2025            offset < le16_to_cpu(sbi->s_es->s_desc_size))
2026                crc = crc16(crc, (__u8 *)gdp + offset,
2027                            le16_to_cpu(sbi->s_es->s_desc_size) -
2028                                offset);
2029
2030out:
2031        return cpu_to_le16(crc);
2032}
2033
2034int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2035                                struct ext4_group_desc *gdp)
2036{
2037        if (ext4_has_group_desc_csum(sb) &&
2038            (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2039                                                      block_group, gdp)))
2040                return 0;
2041
2042        return 1;
2043}
2044
2045void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2046                              struct ext4_group_desc *gdp)
2047{
2048        if (!ext4_has_group_desc_csum(sb))
2049                return;
2050        gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2051}
2052
2053/* Called at mount-time, super-block is locked */
2054static int ext4_check_descriptors(struct super_block *sb,
2055                                  ext4_group_t *first_not_zeroed)
2056{
2057        struct ext4_sb_info *sbi = EXT4_SB(sb);
2058        ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2059        ext4_fsblk_t last_block;
2060        ext4_fsblk_t block_bitmap;
2061        ext4_fsblk_t inode_bitmap;
2062        ext4_fsblk_t inode_table;
2063        int flexbg_flag = 0;
2064        ext4_group_t i, grp = sbi->s_groups_count;
2065
2066        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2067                flexbg_flag = 1;
2068
2069        ext4_debug("Checking group descriptors");
2070
2071        for (i = 0; i < sbi->s_groups_count; i++) {
2072                struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2073
2074                if (i == sbi->s_groups_count - 1 || flexbg_flag)
2075                        last_block = ext4_blocks_count(sbi->s_es) - 1;
2076                else
2077                        last_block = first_block +
2078                                (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2079
2080                if ((grp == sbi->s_groups_count) &&
2081                   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2082                        grp = i;
2083
2084                block_bitmap = ext4_block_bitmap(sb, gdp);
2085                if (block_bitmap < first_block || block_bitmap > last_block) {
2086                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2087                               "Block bitmap for group %u not in group "
2088                               "(block %llu)!", i, block_bitmap);
2089                        return 0;
2090                }
2091                inode_bitmap = ext4_inode_bitmap(sb, gdp);
2092                if (inode_bitmap < first_block || inode_bitmap > last_block) {
2093                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2094                               "Inode bitmap for group %u not in group "
2095                               "(block %llu)!", i, inode_bitmap);
2096                        return 0;
2097                }
2098                inode_table = ext4_inode_table(sb, gdp);
2099                if (inode_table < first_block ||
2100                    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2101                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2102                               "Inode table for group %u not in group "
2103                               "(block %llu)!", i, inode_table);
2104                        return 0;
2105                }
2106                ext4_lock_group(sb, i);
2107                if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2108                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2109                                 "Checksum for group %u failed (%u!=%u)",
2110                                 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2111                                     gdp)), le16_to_cpu(gdp->bg_checksum));
2112                        if (!(sb->s_flags & MS_RDONLY)) {
2113                                ext4_unlock_group(sb, i);
2114                                return 0;
2115                        }
2116                }
2117                ext4_unlock_group(sb, i);
2118                if (!flexbg_flag)
2119                        first_block += EXT4_BLOCKS_PER_GROUP(sb);
2120        }
2121        if (NULL != first_not_zeroed)
2122                *first_not_zeroed = grp;
2123
2124        ext4_free_blocks_count_set(sbi->s_es,
2125                                   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2126        sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2127        return 1;
2128}
2129
2130/* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2131 * the superblock) which were deleted from all directories, but held open by
2132 * a process at the time of a crash.  We walk the list and try to delete these
2133 * inodes at recovery time (only with a read-write filesystem).
2134 *
2135 * In order to keep the orphan inode chain consistent during traversal (in
2136 * case of crash during recovery), we link each inode into the superblock
2137 * orphan list_head and handle it the same way as an inode deletion during
2138 * normal operation (which journals the operations for us).
2139 *
2140 * We only do an iget() and an iput() on each inode, which is very safe if we
2141 * accidentally point at an in-use or already deleted inode.  The worst that
2142 * can happen in this case is that we get a "bit already cleared" message from
2143 * ext4_free_inode().  The only reason we would point at a wrong inode is if
2144 * e2fsck was run on this filesystem, and it must have already done the orphan
2145 * inode cleanup for us, so we can safely abort without any further action.
2146 */
2147static void ext4_orphan_cleanup(struct super_block *sb,
2148                                struct ext4_super_block *es)
2149{
2150        unsigned int s_flags = sb->s_flags;
2151        int nr_orphans = 0, nr_truncates = 0;
2152#ifdef CONFIG_QUOTA
2153        int i;
2154#endif
2155        if (!es->s_last_orphan) {
2156                jbd_debug(4, "no orphan inodes to clean up\n");
2157                return;
2158        }
2159
2160        if (bdev_read_only(sb->s_bdev)) {
2161                ext4_msg(sb, KERN_ERR, "write access "
2162                        "unavailable, skipping orphan cleanup");
2163                return;
2164        }
2165
2166        /* Check if feature set would not allow a r/w mount */
2167        if (!ext4_feature_set_ok(sb, 0)) {
2168                ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2169                         "unknown ROCOMPAT features");
2170                return;
2171        }
2172
2173        if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2174                /* don't clear list on RO mount w/ errors */
2175                if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2176                        jbd_debug(1, "Errors on filesystem, "
2177                                  "clearing orphan list.\n");
2178                        es->s_last_orphan = 0;
2179                }
2180                jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2181                return;
2182        }
2183
2184        if (s_flags & MS_RDONLY) {
2185                ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2186                sb->s_flags &= ~MS_RDONLY;
2187        }
2188#ifdef CONFIG_QUOTA
2189        /* Needed for iput() to work correctly and not trash data */
2190        sb->s_flags |= MS_ACTIVE;
2191        /* Turn on quotas so that they are updated correctly */
2192        for (i = 0; i < MAXQUOTAS; i++) {
2193                if (EXT4_SB(sb)->s_qf_names[i]) {
2194                        int ret = ext4_quota_on_mount(sb, i);
2195                        if (ret < 0)
2196                                ext4_msg(sb, KERN_ERR,
2197                                        "Cannot turn on journaled "
2198                                        "quota: error %d", ret);
2199                }
2200        }
2201#endif
2202
2203        while (es->s_last_orphan) {
2204                struct inode *inode;
2205
2206                inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2207                if (IS_ERR(inode)) {
2208                        es->s_last_orphan = 0;
2209                        break;
2210                }
2211
2212                list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2213                dquot_initialize(inode);
2214                if (inode->i_nlink) {
2215                        ext4_msg(sb, KERN_DEBUG,
2216                                "%s: truncating inode %lu to %lld bytes",
2217                                __func__, inode->i_ino, inode->i_size);
2218                        jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2219                                  inode->i_ino, inode->i_size);
2220                        ext4_truncate(inode);
2221                        nr_truncates++;
2222                } else {
2223                        ext4_msg(sb, KERN_DEBUG,
2224                                "%s: deleting unreferenced inode %lu",
2225                                __func__, inode->i_ino);
2226                        jbd_debug(2, "deleting unreferenced inode %lu\n",
2227                                  inode->i_ino);
2228                        nr_orphans++;
2229                }
2230                iput(inode);  /* The delete magic happens here! */
2231        }
2232
2233#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2234
2235        if (nr_orphans)
2236                ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2237                       PLURAL(nr_orphans));
2238        if (nr_truncates)
2239                ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2240                       PLURAL(nr_truncates));
2241#ifdef CONFIG_QUOTA
2242        /* Turn quotas off */
2243        for (i = 0; i < MAXQUOTAS; i++) {
2244                if (sb_dqopt(sb)->files[i])
2245                        dquot_quota_off(sb, i);
2246        }
2247#endif
2248        sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2249}
2250
2251/*
2252 * Maximal extent format file size.
2253 * Resulting logical blkno at s_maxbytes must fit in our on-disk
2254 * extent format containers, within a sector_t, and within i_blocks
2255 * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2256 * so that won't be a limiting factor.
2257 *
2258 * However there is other limiting factor. We do store extents in the form
2259 * of starting block and length, hence the resulting length of the extent
2260 * covering maximum file size must fit into on-disk format containers as
2261 * well. Given that length is always by 1 unit bigger than max unit (because
2262 * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2263 *
2264 * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2265 */
2266static loff_t ext4_max_size(int blkbits, int has_huge_files)
2267{
2268        loff_t res;
2269        loff_t upper_limit = MAX_LFS_FILESIZE;
2270
2271        /* small i_blocks in vfs inode? */
2272        if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2273                /*
2274                 * CONFIG_LBDAF is not enabled implies the inode
2275                 * i_block represent total blocks in 512 bytes
2276                 * 32 == size of vfs inode i_blocks * 8
2277                 */
2278                upper_limit = (1LL << 32) - 1;
2279
2280                /* total blocks in file system block size */
2281                upper_limit >>= (blkbits - 9);
2282                upper_limit <<= blkbits;
2283        }
2284
2285        /*
2286         * 32-bit extent-start container, ee_block. We lower the maxbytes
2287         * by one fs block, so ee_len can cover the extent of maximum file
2288         * size
2289         */
2290        res = (1LL << 32) - 1;
2291        res <<= blkbits;
2292
2293        /* Sanity check against vm- & vfs- imposed limits */
2294        if (res > upper_limit)
2295                res = upper_limit;
2296
2297        return res;
2298}
2299
2300/*
2301 * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2302 * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2303 * We need to be 1 filesystem block less than the 2^48 sector limit.
2304 */
2305static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2306{
2307        loff_t res = EXT4_NDIR_BLOCKS;
2308        int meta_blocks;
2309        loff_t upper_limit;
2310        /* This is calculated to be the largest file size for a dense, block
2311         * mapped file such that the file's total number of 512-byte sectors,
2312         * including data and all indirect blocks, does not exceed (2^48 - 1).
2313         *
2314         * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2315         * number of 512-byte sectors of the file.
2316         */
2317
2318        if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2319                /*
2320                 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2321                 * the inode i_block field represents total file blocks in
2322                 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2323                 */
2324                upper_limit = (1LL << 32) - 1;
2325
2326                /* total blocks in file system block size */
2327                upper_limit >>= (bits - 9);
2328
2329        } else {
2330                /*
2331                 * We use 48 bit ext4_inode i_blocks
2332                 * With EXT4_HUGE_FILE_FL set the i_blocks
2333                 * represent total number of blocks in
2334                 * file system block size
2335                 */
2336                upper_limit = (1LL << 48) - 1;
2337
2338        }
2339
2340        /* indirect blocks */
2341        meta_blocks = 1;
2342        /* double indirect blocks */
2343        meta_blocks += 1 + (1LL << (bits-2));
2344        /* tripple indirect blocks */
2345        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2346
2347        upper_limit -= meta_blocks;
2348        upper_limit <<= bits;
2349
2350        res += 1LL << (bits-2);
2351        res += 1LL << (2*(bits-2));
2352        res += 1LL << (3*(bits-2));
2353        res <<= bits;
2354        if (res > upper_limit)
2355                res = upper_limit;
2356
2357        if (res > MAX_LFS_FILESIZE)
2358                res = MAX_LFS_FILESIZE;
2359
2360        return res;
2361}
2362
2363static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2364                                   ext4_fsblk_t logical_sb_block, int nr)
2365{
2366        struct ext4_sb_info *sbi = EXT4_SB(sb);
2367        ext4_group_t bg, first_meta_bg;
2368        int has_super = 0;
2369
2370        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2371
2372        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2373            nr < first_meta_bg)
2374                return logical_sb_block + nr + 1;
2375        bg = sbi->s_desc_per_block * nr;
2376        if (ext4_bg_has_super(sb, bg))
2377                has_super = 1;
2378
2379        return (has_super + ext4_group_first_block_no(sb, bg));
2380}
2381
2382/**
2383 * ext4_get_stripe_size: Get the stripe size.
2384 * @sbi: In memory super block info
2385 *
2386 * If we have specified it via mount option, then
2387 * use the mount option value. If the value specified at mount time is
2388 * greater than the blocks per group use the super block value.
2389 * If the super block value is greater than blocks per group return 0.
2390 * Allocator needs it be less than blocks per group.
2391 *
2392 */
2393static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2394{
2395        unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2396        unsigned long stripe_width =
2397                        le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2398        int ret;
2399
2400        if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2401                ret = sbi->s_stripe;
2402        else if (stripe_width <= sbi->s_blocks_per_group)
2403                ret = stripe_width;
2404        else if (stride <= sbi->s_blocks_per_group)
2405                ret = stride;
2406        else
2407                ret = 0;
2408
2409        /*
2410         * If the stripe width is 1, this makes no sense and
2411         * we set it to 0 to turn off stripe handling code.
2412         */
2413        if (ret <= 1)
2414                ret = 0;
2415
2416        return ret;
2417}
2418
2419/* sysfs supprt */
2420
2421struct ext4_attr {
2422        struct attribute attr;
2423        ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2424        ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2425                         const char *, size_t);
2426        int offset;
2427};
2428
2429static int parse_strtoul(const char *buf,
2430                unsigned long max, unsigned long *value)
2431{
2432        char *endp;
2433
2434        *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2435        endp = skip_spaces(endp);
2436        if (*endp || *value > max)
2437                return -EINVAL;
2438
2439        return 0;
2440}
2441
2442static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2443                                              struct ext4_sb_info *sbi,
2444                                              char *buf)
2445{
2446        return snprintf(buf, PAGE_SIZE, "%llu\n",
2447                (s64) EXT4_C2B(sbi,
2448                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2449}
2450
2451static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2452                                         struct ext4_sb_info *sbi, char *buf)
2453{
2454        struct super_block *sb = sbi->s_buddy_cache->i_sb;
2455
2456        if (!sb->s_bdev->bd_part)
2457                return snprintf(buf, PAGE_SIZE, "0\n");
2458        return snprintf(buf, PAGE_SIZE, "%lu\n",
2459                        (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2460                         sbi->s_sectors_written_start) >> 1);
2461}
2462
2463static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2464                                          struct ext4_sb_info *sbi, char *buf)
2465{
2466        struct super_block *sb = sbi->s_buddy_cache->i_sb;
2467
2468        if (!sb->s_bdev->bd_part)
2469                return snprintf(buf, PAGE_SIZE, "0\n");
2470        return snprintf(buf, PAGE_SIZE, "%llu\n",
2471                        (unsigned long long)(sbi->s_kbytes_written +
2472                        ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2473                          EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2474}
2475
2476static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2477                                          struct ext4_sb_info *sbi,
2478                                          const char *buf, size_t count)
2479{
2480        unsigned long t;
2481
2482        if (parse_strtoul(buf, 0x40000000, &t))
2483                return -EINVAL;
2484
2485        if (t && !is_power_of_2(t))
2486                return -EINVAL;
2487
2488        sbi->s_inode_readahead_blks = t;
2489        return count;
2490}
2491
2492static ssize_t sbi_ui_show(struct ext4_attr *a,
2493                           struct ext4_sb_info *sbi, char *buf)
2494{
2495        unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2496
2497        return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2498}
2499
2500static ssize_t sbi_ui_store(struct ext4_attr *a,
2501                            struct ext4_sb_info *sbi,
2502                            const char *buf, size_t count)
2503{
2504        unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2505        unsigned long t;
2506
2507        if (parse_strtoul(buf, 0xffffffff, &t))
2508                return -EINVAL;
2509        *ui = t;
2510        return count;
2511}
2512
2513static ssize_t trigger_test_error(struct ext4_attr *a,
2514                                  struct ext4_sb_info *sbi,
2515                                  const char *buf, size_t count)
2516{
2517        int len = count;
2518
2519        if (!capable(CAP_SYS_ADMIN))
2520                return -EPERM;
2521
2522        if (len && buf[len-1] == '\n')
2523                len--;
2524
2525        if (len)
2526                ext4_error(sbi->s_sb, "%.*s", len, buf);
2527        return count;
2528}
2529
2530#define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2531static struct ext4_attr ext4_attr_##_name = {                   \
2532        .attr = {.name = __stringify(_name), .mode = _mode },   \
2533        .show   = _show,                                        \
2534        .store  = _store,                                       \
2535        .offset = offsetof(struct ext4_sb_info, _elname),       \
2536}
2537#define EXT4_ATTR(name, mode, show, store) \
2538static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2539
2540#define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2541#define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2542#define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2543#define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2544        EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2545#define ATTR_LIST(name) &ext4_attr_##name.attr
2546
2547EXT4_RO_ATTR(delayed_allocation_blocks);
2548EXT4_RO_ATTR(session_write_kbytes);
2549EXT4_RO_ATTR(lifetime_write_kbytes);
2550EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2551                 inode_readahead_blks_store, s_inode_readahead_blks);
2552EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2553EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2554EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2555EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2556EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2557EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2558EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2559EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2560EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2561EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2562
2563static struct attribute *ext4_attrs[] = {
2564        ATTR_LIST(delayed_allocation_blocks),
2565        ATTR_LIST(session_write_kbytes),
2566        ATTR_LIST(lifetime_write_kbytes),
2567        ATTR_LIST(inode_readahead_blks),
2568        ATTR_LIST(inode_goal),
2569        ATTR_LIST(mb_stats),
2570        ATTR_LIST(mb_max_to_scan),
2571        ATTR_LIST(mb_min_to_scan),
2572        ATTR_LIST(mb_order2_req),
2573        ATTR_LIST(mb_stream_req),
2574        ATTR_LIST(mb_group_prealloc),
2575        ATTR_LIST(max_writeback_mb_bump),
2576        ATTR_LIST(extent_max_zeroout_kb),
2577        ATTR_LIST(trigger_fs_error),
2578        NULL,
2579};
2580
2581/* Features this copy of ext4 supports */
2582EXT4_INFO_ATTR(lazy_itable_init);
2583EXT4_INFO_ATTR(batched_discard);
2584EXT4_INFO_ATTR(meta_bg_resize);
2585
2586static struct attribute *ext4_feat_attrs[] = {
2587        ATTR_LIST(lazy_itable_init),
2588        ATTR_LIST(batched_discard),
2589        ATTR_LIST(meta_bg_resize),
2590        NULL,
2591};
2592
2593static ssize_t ext4_attr_show(struct kobject *kobj,
2594                              struct attribute *attr, char *buf)
2595{
2596        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2597                                                s_kobj);
2598        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2599
2600        return a->show ? a->show(a, sbi, buf) : 0;
2601}
2602
2603static ssize_t ext4_attr_store(struct kobject *kobj,
2604                               struct attribute *attr,
2605                               const char *buf, size_t len)
2606{
2607        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2608                                                s_kobj);
2609        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2610
2611        return a->store ? a->store(a, sbi, buf, len) : 0;
2612}
2613
2614static void ext4_sb_release(struct kobject *kobj)
2615{
2616        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2617                                                s_kobj);
2618        complete(&sbi->s_kobj_unregister);
2619}
2620
2621static const struct sysfs_ops ext4_attr_ops = {
2622        .show   = ext4_attr_show,
2623        .store  = ext4_attr_store,
2624};
2625
2626static struct kobj_type ext4_ktype = {
2627        .default_attrs  = ext4_attrs,
2628        .sysfs_ops      = &ext4_attr_ops,
2629        .release        = ext4_sb_release,
2630};
2631
2632static void ext4_feat_release(struct kobject *kobj)
2633{
2634        complete(&ext4_feat->f_kobj_unregister);
2635}
2636
2637static struct kobj_type ext4_feat_ktype = {
2638        .default_attrs  = ext4_feat_attrs,
2639        .sysfs_ops      = &ext4_attr_ops,
2640        .release        = ext4_feat_release,
2641};
2642
2643/*
2644 * Check whether this filesystem can be mounted based on
2645 * the features present and the RDONLY/RDWR mount requested.
2646 * Returns 1 if this filesystem can be mounted as requested,
2647 * 0 if it cannot be.
2648 */
2649static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2650{
2651        if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2652                ext4_msg(sb, KERN_ERR,
2653                        "Couldn't mount because of "
2654                        "unsupported optional features (%x)",
2655                        (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2656                        ~EXT4_FEATURE_INCOMPAT_SUPP));
2657                return 0;
2658        }
2659
2660        if (readonly)
2661                return 1;
2662
2663        /* Check that feature set is OK for a read-write mount */
2664        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2665                ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2666                         "unsupported optional features (%x)",
2667                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2668                                ~EXT4_FEATURE_RO_COMPAT_SUPP));
2669                return 0;
2670        }
2671        /*
2672         * Large file size enabled file system can only be mounted
2673         * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2674         */
2675        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2676                if (sizeof(blkcnt_t) < sizeof(u64)) {
2677                        ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2678                                 "cannot be mounted RDWR without "
2679                                 "CONFIG_LBDAF");
2680                        return 0;
2681                }
2682        }
2683        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2684            !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2685                ext4_msg(sb, KERN_ERR,
2686                         "Can't support bigalloc feature without "
2687                         "extents feature\n");
2688                return 0;
2689        }
2690
2691#ifndef CONFIG_QUOTA
2692        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2693            !readonly) {
2694                ext4_msg(sb, KERN_ERR,
2695                         "Filesystem with quota feature cannot be mounted RDWR "
2696                         "without CONFIG_QUOTA");
2697                return 0;
2698        }
2699#endif  /* CONFIG_QUOTA */
2700        return 1;
2701}
2702
2703/*
2704 * This function is called once a day if we have errors logged
2705 * on the file system
2706 */
2707static void print_daily_error_info(unsigned long arg)
2708{
2709        struct super_block *sb = (struct super_block *) arg;
2710        struct ext4_sb_info *sbi;
2711        struct ext4_super_block *es;
2712
2713        sbi = EXT4_SB(sb);
2714        es = sbi->s_es;
2715
2716        if (es->s_error_count)
2717                ext4_msg(sb, KERN_NOTICE, "error count: %u",
2718                         le32_to_cpu(es->s_error_count));
2719        if (es->s_first_error_time) {
2720                printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2721                       sb->s_id, le32_to_cpu(es->s_first_error_time),
2722                       (int) sizeof(es->s_first_error_func),
2723                       es->s_first_error_func,
2724                       le32_to_cpu(es->s_first_error_line));
2725                if (es->s_first_error_ino)
2726                        printk(": inode %u",
2727                               le32_to_cpu(es->s_first_error_ino));
2728                if (es->s_first_error_block)
2729                        printk(": block %llu", (unsigned long long)
2730                               le64_to_cpu(es->s_first_error_block));
2731                printk("\n");
2732        }
2733        if (es->s_last_error_time) {
2734                printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2735                       sb->s_id, le32_to_cpu(es->s_last_error_time),
2736                       (int) sizeof(es->s_last_error_func),
2737                       es->s_last_error_func,
2738                       le32_to_cpu(es->s_last_error_line));
2739                if (es->s_last_error_ino)
2740                        printk(": inode %u",
2741                               le32_to_cpu(es->s_last_error_ino));
2742                if (es->s_last_error_block)
2743                        printk(": block %llu", (unsigned long long)
2744                               le64_to_cpu(es->s_last_error_block));
2745                printk("\n");
2746        }
2747        mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2748}
2749
2750/* Find next suitable group and run ext4_init_inode_table */
2751static int ext4_run_li_request(struct ext4_li_request *elr)
2752{
2753        struct ext4_group_desc *gdp = NULL;
2754        ext4_group_t group, ngroups;
2755        struct super_block *sb;
2756        unsigned long timeout = 0;
2757        int ret = 0;
2758
2759        sb = elr->lr_super;
2760        ngroups = EXT4_SB(sb)->s_groups_count;
2761
2762        sb_start_write(sb);
2763        for (group = elr->lr_next_group; group < ngroups; group++) {
2764                gdp = ext4_get_group_desc(sb, group, NULL);
2765                if (!gdp) {
2766                        ret = 1;
2767                        break;
2768                }
2769
2770                if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2771                        break;
2772        }
2773
2774        if (group == ngroups)
2775                ret = 1;
2776
2777        if (!ret) {
2778                timeout = jiffies;
2779                ret = ext4_init_inode_table(sb, group,
2780                                            elr->lr_timeout ? 0 : 1);
2781                if (elr->lr_timeout == 0) {
2782                        timeout = (jiffies - timeout) *
2783                                  elr->lr_sbi->s_li_wait_mult;
2784                        elr->lr_timeout = timeout;
2785                }
2786                elr->lr_next_sched = jiffies + elr->lr_timeout;
2787                elr->lr_next_group = group + 1;
2788        }
2789        sb_end_write(sb);
2790
2791        return ret;
2792}
2793
2794/*
2795 * Remove lr_request from the list_request and free the
2796 * request structure. Should be called with li_list_mtx held
2797 */
2798static void ext4_remove_li_request(struct ext4_li_request *elr)
2799{
2800        struct ext4_sb_info *sbi;
2801
2802        if (!elr)
2803                return;
2804
2805        sbi = elr->lr_sbi;
2806
2807        list_del(&elr->lr_request);
2808        sbi->s_li_request = NULL;
2809        kfree(elr);
2810}
2811
2812static void ext4_unregister_li_request(struct super_block *sb)
2813{
2814        mutex_lock(&ext4_li_mtx);
2815        if (!ext4_li_info) {
2816                mutex_unlock(&ext4_li_mtx);
2817                return;
2818        }
2819
2820        mutex_lock(&ext4_li_info->li_list_mtx);
2821        ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2822        mutex_unlock(&ext4_li_info->li_list_mtx);
2823        mutex_unlock(&ext4_li_mtx);
2824}
2825
2826static struct task_struct *ext4_lazyinit_task;
2827
2828/*
2829 * This is the function where ext4lazyinit thread lives. It walks
2830 * through the request list searching for next scheduled filesystem.
2831 * When such a fs is found, run the lazy initialization request
2832 * (ext4_rn_li_request) and keep track of the time spend in this
2833 * function. Based on that time we compute next schedule time of
2834 * the request. When walking through the list is complete, compute
2835 * next waking time and put itself into sleep.
2836 */
2837static int ext4_lazyinit_thread(void *arg)
2838{
2839        struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2840        struct list_head *pos, *n;
2841        struct ext4_li_request *elr;
2842        unsigned long next_wakeup, cur;
2843
2844        BUG_ON(NULL == eli);
2845
2846cont_thread:
2847        while (true) {
2848                next_wakeup = MAX_JIFFY_OFFSET;
2849
2850                mutex_lock(&eli->li_list_mtx);
2851                if (list_empty(&eli->li_request_list)) {
2852                        mutex_unlock(&eli->li_list_mtx);
2853                        goto exit_thread;
2854                }
2855
2856                list_for_each_safe(pos, n, &eli->li_request_list) {
2857                        elr = list_entry(pos, struct ext4_li_request,
2858                                         lr_request);
2859
2860                        if (time_after_eq(jiffies, elr->lr_next_sched)) {
2861                                if (ext4_run_li_request(elr) != 0) {
2862                                        /* error, remove the lazy_init job */
2863                                        ext4_remove_li_request(elr);
2864                                        continue;
2865                                }
2866                        }
2867
2868                        if (time_before(elr->lr_next_sched, next_wakeup))
2869                                next_wakeup = elr->lr_next_sched;
2870                }
2871                mutex_unlock(&eli->li_list_mtx);
2872
2873                try_to_freeze();
2874
2875                cur = jiffies;
2876                if ((time_after_eq(cur, next_wakeup)) ||
2877                    (MAX_JIFFY_OFFSET == next_wakeup)) {
2878                        cond_resched();
2879                        continue;
2880                }
2881
2882                schedule_timeout_interruptible(next_wakeup - cur);
2883
2884                if (kthread_should_stop()) {
2885                        ext4_clear_request_list();
2886                        goto exit_thread;
2887                }
2888        }
2889
2890exit_thread:
2891        /*
2892         * It looks like the request list is empty, but we need
2893         * to check it under the li_list_mtx lock, to prevent any
2894         * additions into it, and of course we should lock ext4_li_mtx
2895         * to atomically free the list and ext4_li_info, because at
2896         * this point another ext4 filesystem could be registering
2897         * new one.
2898         */
2899        mutex_lock(&ext4_li_mtx);
2900        mutex_lock(&eli->li_list_mtx);
2901        if (!list_empty(&eli->li_request_list)) {
2902                mutex_unlock(&eli->li_list_mtx);
2903                mutex_unlock(&ext4_li_mtx);
2904                goto cont_thread;
2905        }
2906        mutex_unlock(&eli->li_list_mtx);
2907        kfree(ext4_li_info);
2908        ext4_li_info = NULL;
2909        mutex_unlock(&ext4_li_mtx);
2910
2911        return 0;
2912}
2913
2914static void ext4_clear_request_list(void)
2915{
2916        struct list_head *pos, *n;
2917        struct ext4_li_request *elr;
2918
2919        mutex_lock(&ext4_li_info->li_list_mtx);
2920        list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2921                elr = list_entry(pos, struct ext4_li_request,
2922                                 lr_request);
2923                ext4_remove_li_request(elr);
2924        }
2925        mutex_unlock(&ext4_li_info->li_list_mtx);
2926}
2927
2928static int ext4_run_lazyinit_thread(void)
2929{
2930        ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2931                                         ext4_li_info, "ext4lazyinit");
2932        if (IS_ERR(ext4_lazyinit_task)) {
2933                int err = PTR_ERR(ext4_lazyinit_task);
2934                ext4_clear_request_list();
2935                kfree(ext4_li_info);
2936                ext4_li_info = NULL;
2937                printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2938                                 "initialization thread\n",
2939                                 err);
2940                return err;
2941        }
2942        ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2943        return 0;
2944}
2945
2946/*
2947 * Check whether it make sense to run itable init. thread or not.
2948 * If there is at least one uninitialized inode table, return
2949 * corresponding group number, else the loop goes through all
2950 * groups and return total number of groups.
2951 */
2952static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2953{
2954        ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2955        struct ext4_group_desc *gdp = NULL;
2956
2957        for (group = 0; group < ngroups; group++) {
2958                gdp = ext4_get_group_desc(sb, group, NULL);
2959                if (!gdp)
2960                        continue;
2961
2962                if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2963                        break;
2964        }
2965
2966        return group;
2967}
2968
2969static int ext4_li_info_new(void)
2970{
2971        struct ext4_lazy_init *eli = NULL;
2972
2973        eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2974        if (!eli)
2975                return -ENOMEM;
2976
2977        INIT_LIST_HEAD(&eli->li_request_list);
2978        mutex_init(&eli->li_list_mtx);
2979
2980        eli->li_state |= EXT4_LAZYINIT_QUIT;
2981
2982        ext4_li_info = eli;
2983
2984        return 0;
2985}
2986
2987static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2988                                            ext4_group_t start)
2989{
2990        struct ext4_sb_info *sbi = EXT4_SB(sb);
2991        struct ext4_li_request *elr;
2992        unsigned long rnd;
2993
2994        elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2995        if (!elr)
2996                return NULL;
2997
2998        elr->lr_super = sb;
2999        elr->lr_sbi = sbi;
3000        elr->lr_next_group = start;
3001
3002        /*
3003         * Randomize first schedule time of the request to
3004         * spread the inode table initialization requests
3005         * better.
3006         */
3007        get_random_bytes(&rnd, sizeof(rnd));
3008        elr->lr_next_sched = jiffies + (unsigned long)rnd %
3009                             (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3010
3011        return elr;
3012}
3013
3014static int ext4_register_li_request(struct super_block *sb,
3015                                    ext4_group_t first_not_zeroed)
3016{
3017        struct ext4_sb_info *sbi = EXT4_SB(sb);
3018        struct ext4_li_request *elr;
3019        ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3020        int ret = 0;
3021
3022        if (sbi->s_li_request != NULL) {
3023                /*
3024                 * Reset timeout so it can be computed again, because
3025                 * s_li_wait_mult might have changed.
3026                 */
3027                sbi->s_li_request->lr_timeout = 0;
3028                return 0;
3029        }
3030
3031        if (first_not_zeroed == ngroups ||
3032            (sb->s_flags & MS_RDONLY) ||
3033            !test_opt(sb, INIT_INODE_TABLE))
3034                return 0;
3035
3036        elr = ext4_li_request_new(sb, first_not_zeroed);
3037        if (!elr)
3038                return -ENOMEM;
3039
3040        mutex_lock(&ext4_li_mtx);
3041
3042        if (NULL == ext4_li_info) {
3043                ret = ext4_li_info_new();
3044                if (ret)
3045                        goto out;
3046        }
3047
3048        mutex_lock(&ext4_li_info->li_list_mtx);
3049        list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3050        mutex_unlock(&ext4_li_info->li_list_mtx);
3051
3052        sbi->s_li_request = elr;
3053        /*
3054         * set elr to NULL here since it has been inserted to
3055         * the request_list and the removal and free of it is
3056         * handled by ext4_clear_request_list from now on.
3057         */
3058        elr = NULL;
3059
3060        if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3061                ret = ext4_run_lazyinit_thread();
3062                if (ret)
3063                        goto out;
3064        }
3065out:
3066        mutex_unlock(&ext4_li_mtx);
3067        if (ret)
3068                kfree(elr);
3069        return ret;
3070}
3071
3072/*
3073 * We do not need to lock anything since this is called on
3074 * module unload.
3075 */
3076static void ext4_destroy_lazyinit_thread(void)
3077{
3078        /*
3079         * If thread exited earlier
3080         * there's nothing to be done.
3081         */
3082        if (!ext4_li_info || !ext4_lazyinit_task)
3083                return;
3084
3085        kthread_stop(ext4_lazyinit_task);
3086}
3087
3088static int set_journal_csum_feature_set(struct super_block *sb)
3089{
3090        int ret = 1;
3091        int compat, incompat;
3092        struct ext4_sb_info *sbi = EXT4_SB(sb);
3093
3094        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3095                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3096                /* journal checksum v2 */
3097                compat = 0;
3098                incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3099        } else {
3100                /* journal checksum v1 */
3101                compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3102                incompat = 0;
3103        }
3104
3105        if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3106                ret = jbd2_journal_set_features(sbi->s_journal,
3107                                compat, 0,
3108                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3109                                incompat);
3110        } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3111                ret = jbd2_journal_set_features(sbi->s_journal,
3112                                compat, 0,
3113                                incompat);
3114                jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3115                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3116        } else {
3117                jbd2_journal_clear_features(sbi->s_journal,
3118                                JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3119                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3120                                JBD2_FEATURE_INCOMPAT_CSUM_V2);
3121        }
3122
3123        return ret;
3124}
3125
3126/*
3127 * Note: calculating the overhead so we can be compatible with
3128 * historical BSD practice is quite difficult in the face of
3129 * clusters/bigalloc.  This is because multiple metadata blocks from
3130 * different block group can end up in the same allocation cluster.
3131 * Calculating the exact overhead in the face of clustered allocation
3132 * requires either O(all block bitmaps) in memory or O(number of block
3133 * groups**2) in time.  We will still calculate the superblock for
3134 * older file systems --- and if we come across with a bigalloc file
3135 * system with zero in s_overhead_clusters the estimate will be close to
3136 * correct especially for very large cluster sizes --- but for newer
3137 * file systems, it's better to calculate this figure once at mkfs
3138 * time, and store it in the superblock.  If the superblock value is
3139 * present (even for non-bigalloc file systems), we will use it.
3140 */
3141static int count_overhead(struct super_block *sb, ext4_group_t grp,
3142                          char *buf)
3143{
3144        struct ext4_sb_info     *sbi = EXT4_SB(sb);
3145        struct ext4_group_desc  *gdp;
3146        ext4_fsblk_t            first_block, last_block, b;
3147        ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3148        int                     s, j, count = 0;
3149
3150        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3151                return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3152                        sbi->s_itb_per_group + 2);
3153
3154        first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3155                (grp * EXT4_BLOCKS_PER_GROUP(sb));
3156        last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3157        for (i = 0; i < ngroups; i++) {
3158                gdp = ext4_get_group_desc(sb, i, NULL);
3159                b = ext4_block_bitmap(sb, gdp);
3160                if (b >= first_block && b <= last_block) {
3161                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3162                        count++;
3163                }
3164                b = ext4_inode_bitmap(sb, gdp);
3165                if (b >= first_block && b <= last_block) {
3166                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3167                        count++;
3168                }
3169                b = ext4_inode_table(sb, gdp);
3170                if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3171                        for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3172                                int c = EXT4_B2C(sbi, b - first_block);
3173                                ext4_set_bit(c, buf);
3174                                count++;
3175                        }
3176                if (i != grp)
3177                        continue;
3178                s = 0;
3179                if (ext4_bg_has_super(sb, grp)) {
3180                        ext4_set_bit(s++, buf);
3181                        count++;
3182                }
3183                for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3184                        ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3185                        count++;
3186                }
3187        }
3188        if (!count)
3189                return 0;
3190        return EXT4_CLUSTERS_PER_GROUP(sb) -
3191                ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3192}
3193
3194/*
3195 * Compute the overhead and stash it in sbi->s_overhead
3196 */
3197int ext4_calculate_overhead(struct super_block *sb)
3198{
3199        struct ext4_sb_info *sbi = EXT4_SB(sb);
3200        struct ext4_super_block *es = sbi->s_es;
3201        ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3202        ext4_fsblk_t overhead = 0;
3203        char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3204
3205        memset(buf, 0, PAGE_SIZE);
3206        if (!buf)
3207                return -ENOMEM;
3208
3209        /*
3210         * Compute the overhead (FS structures).  This is constant
3211         * for a given filesystem unless the number of block groups
3212         * changes so we cache the previous value until it does.
3213         */
3214
3215        /*
3216         * All of the blocks before first_data_block are overhead
3217         */
3218        overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3219
3220        /*
3221         * Add the overhead found in each block group
3222         */
3223        for (i = 0; i < ngroups; i++) {
3224                int blks;
3225
3226                blks = count_overhead(sb, i, buf);
3227                overhead += blks;
3228                if (blks)
3229                        memset(buf, 0, PAGE_SIZE);
3230                cond_resched();
3231        }
3232        sbi->s_overhead = overhead;
3233        smp_wmb();
3234        free_page((unsigned long) buf);
3235        return 0;
3236}
3237
3238static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3239{
3240        char *orig_data = kstrdup(data, GFP_KERNEL);
3241        struct buffer_head *bh;
3242        struct ext4_super_block *es = NULL;
3243        struct ext4_sb_info *sbi;
3244        ext4_fsblk_t block;
3245        ext4_fsblk_t sb_block = get_sb_block(&data);
3246        ext4_fsblk_t logical_sb_block;
3247        unsigned long offset = 0;
3248        unsigned long journal_devnum = 0;
3249        unsigned long def_mount_opts;
3250        struct inode *root;
3251        char *cp;
3252        const char *descr;
3253        int ret = -ENOMEM;
3254        int blocksize, clustersize;
3255        unsigned int db_count;
3256        unsigned int i;
3257        int needs_recovery, has_huge_files, has_bigalloc;
3258        __u64 blocks_count;
3259        int err;
3260        unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3261        ext4_group_t first_not_zeroed;
3262
3263        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3264        if (!sbi)
3265                goto out_free_orig;
3266
3267        sbi->s_blockgroup_lock =
3268                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3269        if (!sbi->s_blockgroup_lock) {
3270                kfree(sbi);
3271                goto out_free_orig;
3272        }
3273        sb->s_fs_info = sbi;
3274        sbi->s_sb = sb;
3275        sbi->s_mount_opt = 0;
3276        sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
3277        sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
3278        sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3279        sbi->s_sb_block = sb_block;
3280        if (sb->s_bdev->bd_part)
3281                sbi->s_sectors_written_start =
3282                        part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3283
3284        /* Cleanup superblock name */
3285        for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3286                *cp = '!';
3287
3288        ret = -EINVAL;
3289        blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3290        if (!blocksize) {
3291                ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3292                goto out_fail;
3293        }
3294
3295        /*
3296         * The ext4 superblock will not be buffer aligned for other than 1kB
3297         * block sizes.  We need to calculate the offset from buffer start.
3298         */
3299        if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3300                logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3301                offset = do_div(logical_sb_block, blocksize);
3302        } else {
3303                logical_sb_block = sb_block;
3304        }
3305
3306        if (!(bh = sb_bread(sb, logical_sb_block))) {
3307                ext4_msg(sb, KERN_ERR, "unable to read superblock");
3308                goto out_fail;
3309        }
3310        /*
3311         * Note: s_es must be initialized as soon as possible because
3312         *       some ext4 macro-instructions depend on its value
3313         */
3314        es = (struct ext4_super_block *) (bh->b_data + offset);
3315        sbi->s_es = es;
3316        sb->s_magic = le16_to_cpu(es->s_magic);
3317        if (sb->s_magic != EXT4_SUPER_MAGIC)
3318                goto cantfind_ext4;
3319        sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3320
3321        /* Warn if metadata_csum and gdt_csum are both set. */
3322        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3323                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3324            EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3325                ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3326                             "redundant flags; please run fsck.");
3327
3328        /* Check for a known checksum algorithm */
3329        if (!ext4_verify_csum_type(sb, es)) {
3330                ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3331                         "unknown checksum algorithm.");
3332                silent = 1;
3333                goto cantfind_ext4;
3334        }
3335
3336        /* Load the checksum driver */
3337        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3338                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3339                sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3340                if (IS_ERR(sbi->s_chksum_driver)) {
3341                        ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3342                        ret = PTR_ERR(sbi->s_chksum_driver);
3343                        sbi->s_chksum_driver = NULL;
3344                        goto failed_mount;
3345                }
3346        }
3347
3348        /* Check superblock checksum */
3349        if (!ext4_superblock_csum_verify(sb, es)) {
3350                ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3351                         "invalid superblock checksum.  Run e2fsck?");
3352                silent = 1;
3353                goto cantfind_ext4;
3354        }
3355
3356        /* Precompute checksum seed for all metadata */
3357        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3358                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3359                sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3360                                               sizeof(es->s_uuid));
3361
3362        /* Set defaults before we parse the mount options */
3363        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3364        set_opt(sb, INIT_INODE_TABLE);
3365        if (def_mount_opts & EXT4_DEFM_DEBUG)
3366                set_opt(sb, DEBUG);
3367        if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3368                set_opt(sb, GRPID);
3369        if (def_mount_opts & EXT4_DEFM_UID16)
3370                set_opt(sb, NO_UID32);
3371        /* xattr user namespace & acls are now defaulted on */
3372#ifdef CONFIG_EXT4_FS_XATTR
3373        set_opt(sb, XATTR_USER);
3374#endif
3375#ifdef CONFIG_EXT4_FS_POSIX_ACL
3376        set_opt(sb, POSIX_ACL);
3377#endif
3378        set_opt(sb, MBLK_IO_SUBMIT);
3379        if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3380                set_opt(sb, JOURNAL_DATA);
3381        else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3382                set_opt(sb, ORDERED_DATA);
3383        else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3384                set_opt(sb, WRITEBACK_DATA);
3385
3386        if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3387                set_opt(sb, ERRORS_PANIC);
3388        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3389                set_opt(sb, ERRORS_CONT);
3390        else
3391                set_opt(sb, ERRORS_RO);
3392        if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3393                set_opt(sb, BLOCK_VALIDITY);
3394        if (def_mount_opts & EXT4_DEFM_DISCARD)
3395                set_opt(sb, DISCARD);
3396
3397        sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3398        sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3399        sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3400        sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3401        sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3402
3403        if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3404                set_opt(sb, BARRIER);
3405
3406        /*
3407         * enable delayed allocation by default
3408         * Use -o nodelalloc to turn it off
3409         */
3410        if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3411            ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3412                set_opt(sb, DELALLOC);
3413
3414        /*
3415         * set default s_li_wait_mult for lazyinit, for the case there is
3416         * no mount option specified.
3417         */
3418        sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3419
3420        if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3421                           &journal_devnum, &journal_ioprio, 0)) {
3422                ext4_msg(sb, KERN_WARNING,
3423                         "failed to parse options in superblock: %s",
3424                         sbi->s_es->s_mount_opts);
3425        }
3426        sbi->s_def_mount_opt = sbi->s_mount_opt;
3427        if (!parse_options((char *) data, sb, &journal_devnum,
3428                           &journal_ioprio, 0))
3429                goto failed_mount;
3430
3431        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3432                printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3433                            "with data=journal disables delayed "
3434                            "allocation and O_DIRECT support!\n");
3435                if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3436                        ext4_msg(sb, KERN_ERR, "can't mount with "
3437                                 "both data=journal and delalloc");
3438                        goto failed_mount;
3439                }
3440                if (test_opt(sb, DIOREAD_NOLOCK)) {
3441                        ext4_msg(sb, KERN_ERR, "can't mount with "
3442                                 "both data=journal and delalloc");
3443                        goto failed_mount;
3444                }
3445                if (test_opt(sb, DELALLOC))
3446                        clear_opt(sb, DELALLOC);
3447        }
3448
3449        blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3450        if (test_opt(sb, DIOREAD_NOLOCK)) {
3451                if (blocksize < PAGE_SIZE) {
3452                        ext4_msg(sb, KERN_ERR, "can't mount with "
3453                                 "dioread_nolock if block size != PAGE_SIZE");
3454                        goto failed_mount;
3455                }
3456        }
3457
3458        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3459                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3460
3461        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3462            (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3463             EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3464             EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3465                ext4_msg(sb, KERN_WARNING,
3466                       "feature flags set on rev 0 fs, "
3467                       "running e2fsck is recommended");
3468
3469        if (IS_EXT2_SB(sb)) {
3470                if (ext2_feature_set_ok(sb))
3471                        ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3472                                 "using the ext4 subsystem");
3473                else {
3474                        ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3475                                 "to feature incompatibilities");
3476                        goto failed_mount;
3477                }
3478        }
3479
3480        if (IS_EXT3_SB(sb)) {
3481                if (ext3_feature_set_ok(sb))
3482                        ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3483                                 "using the ext4 subsystem");
3484                else {
3485                        ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3486                                 "to feature incompatibilities");
3487                        goto failed_mount;
3488                }
3489        }
3490
3491        /*
3492         * Check feature flags regardless of the revision level, since we
3493         * previously didn't change the revision level when setting the flags,
3494         * so there is a chance incompat flags are set on a rev 0 filesystem.
3495         */
3496        if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3497                goto failed_mount;
3498
3499        if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3500            blocksize > EXT4_MAX_BLOCK_SIZE) {
3501                ext4_msg(sb, KERN_ERR,
3502                       "Unsupported filesystem blocksize %d", blocksize);
3503                goto failed_mount;
3504        }
3505
3506        if (sb->s_blocksize != blocksize) {
3507                /* Validate the filesystem blocksize */
3508                if (!sb_set_blocksize(sb, blocksize)) {
3509                        ext4_msg(sb, KERN_ERR, "bad block size %d",
3510                                        blocksize);
3511                        goto failed_mount;
3512                }
3513
3514                brelse(bh);
3515                logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3516                offset = do_div(logical_sb_block, blocksize);
3517                bh = sb_bread(sb, logical_sb_block);
3518                if (!bh) {
3519                        ext4_msg(sb, KERN_ERR,
3520                               "Can't read superblock on 2nd try");
3521                        goto failed_mount;
3522                }
3523                es = (struct ext4_super_block *)(bh->b_data + offset);
3524                sbi->s_es = es;
3525                if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3526                        ext4_msg(sb, KERN_ERR,
3527                               "Magic mismatch, very weird!");
3528                        goto failed_mount;
3529                }
3530        }
3531
3532        has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3533                                EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3534        sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3535                                                      has_huge_files);
3536        sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3537
3538        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3539                sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3540                sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3541        } else {
3542                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3543                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3544                if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3545                    (!is_power_of_2(sbi->s_inode_size)) ||
3546                    (sbi->s_inode_size > blocksize)) {
3547                        ext4_msg(sb, KERN_ERR,
3548                               "unsupported inode size: %d",
3549                               sbi->s_inode_size);
3550                        goto failed_mount;
3551                }
3552                if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3553                        sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3554        }
3555
3556        sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3557        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3558                if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3559                    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3560                    !is_power_of_2(sbi->s_desc_size)) {
3561                        ext4_msg(sb, KERN_ERR,
3562                               "unsupported descriptor size %lu",
3563                               sbi->s_desc_size);
3564                        goto failed_mount;
3565                }
3566        } else
3567                sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3568
3569        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3570        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3571        if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3572                goto cantfind_ext4;
3573
3574        sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3575        if (sbi->s_inodes_per_block == 0)
3576                goto cantfind_ext4;
3577        sbi->s_itb_per_group = sbi->s_inodes_per_group /
3578                                        sbi->s_inodes_per_block;
3579        sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3580        sbi->s_sbh = bh;
3581        sbi->s_mount_state = le16_to_cpu(es->s_state);
3582        sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3583        sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3584
3585        for (i = 0; i < 4; i++)
3586                sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3587        sbi->s_def_hash_version = es->s_def_hash_version;
3588        i = le32_to_cpu(es->s_flags);
3589        if (i & EXT2_FLAGS_UNSIGNED_HASH)
3590                sbi->s_hash_unsigned = 3;
3591        else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3592#ifdef __CHAR_UNSIGNED__
3593                es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3594                sbi->s_hash_unsigned = 3;
3595#else
3596                es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3597#endif
3598        }
3599
3600        /* Handle clustersize */
3601        clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3602        has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3603                                EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3604        if (has_bigalloc) {
3605                if (clustersize < blocksize) {
3606                        ext4_msg(sb, KERN_ERR,
3607                                 "cluster size (%d) smaller than "
3608                                 "block size (%d)", clustersize, blocksize);
3609                        goto failed_mount;
3610                }
3611                sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3612                        le32_to_cpu(es->s_log_block_size);
3613                sbi->s_clusters_per_group =
3614                        le32_to_cpu(es->s_clusters_per_group);
3615                if (sbi->s_clusters_per_group > blocksize * 8) {
3616                        ext4_msg(sb, KERN_ERR,
3617                                 "#clusters per group too big: %lu",
3618                                 sbi->s_clusters_per_group);
3619                        goto failed_mount;
3620                }
3621                if (sbi->s_blocks_per_group !=
3622                    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3623                        ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3624                                 "clusters per group (%lu) inconsistent",
3625                                 sbi->s_blocks_per_group,
3626                                 sbi->s_clusters_per_group);
3627                        goto failed_mount;
3628                }
3629        } else {
3630                if (clustersize != blocksize) {
3631                        ext4_warning(sb, "fragment/cluster size (%d) != "
3632                                     "block size (%d)", clustersize,
3633                                     blocksize);
3634                        clustersize = blocksize;
3635                }
3636                if (sbi->s_blocks_per_group > blocksize * 8) {
3637                        ext4_msg(sb, KERN_ERR,
3638                                 "#blocks per group too big: %lu",
3639                                 sbi->s_blocks_per_group);
3640                        goto failed_mount;
3641                }
3642                sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3643                sbi->s_cluster_bits = 0;
3644        }
3645        sbi->s_cluster_ratio = clustersize / blocksize;
3646
3647        if (sbi->s_inodes_per_group > blocksize * 8) {
3648                ext4_msg(sb, KERN_ERR,
3649                       "#inodes per group too big: %lu",
3650                       sbi->s_inodes_per_group);
3651                goto failed_mount;
3652        }
3653
3654        /*
3655         * Test whether we have more sectors than will fit in sector_t,
3656         * and whether the max offset is addressable by the page cache.
3657         */
3658        err = generic_check_addressable(sb->s_blocksize_bits,
3659                                        ext4_blocks_count(es));
3660        if (err) {
3661                ext4_msg(sb, KERN_ERR, "filesystem"
3662                         " too large to mount safely on this system");
3663                if (sizeof(sector_t) < 8)
3664                        ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3665                ret = err;
3666                goto failed_mount;
3667        }
3668
3669        if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3670                goto cantfind_ext4;
3671
3672        /* check blocks count against device size */
3673        blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3674        if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3675                ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3676                       "exceeds size of device (%llu blocks)",
3677                       ext4_blocks_count(es), blocks_count);
3678                goto failed_mount;
3679        }
3680
3681        /*
3682         * It makes no sense for the first data block to be beyond the end
3683         * of the filesystem.
3684         */
3685        if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3686                ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3687                         "block %u is beyond end of filesystem (%llu)",
3688                         le32_to_cpu(es->s_first_data_block),
3689                         ext4_blocks_count(es));
3690                goto failed_mount;
3691        }
3692        blocks_count = (ext4_blocks_count(es) -
3693                        le32_to_cpu(es->s_first_data_block) +
3694                        EXT4_BLOCKS_PER_GROUP(sb) - 1);
3695        do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3696        if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3697                ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3698                       "(block count %llu, first data block %u, "
3699                       "blocks per group %lu)", sbi->s_groups_count,
3700                       ext4_blocks_count(es),
3701                       le32_to_cpu(es->s_first_data_block),
3702                       EXT4_BLOCKS_PER_GROUP(sb));
3703                goto failed_mount;
3704        }
3705        sbi->s_groups_count = blocks_count;
3706        sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3707                        (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3708        db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3709                   EXT4_DESC_PER_BLOCK(sb);
3710        sbi->s_group_desc = ext4_kvmalloc(db_count *
3711                                          sizeof(struct buffer_head *),
3712                                          GFP_KERNEL);
3713        if (sbi->s_group_desc == NULL) {
3714                ext4_msg(sb, KERN_ERR, "not enough memory");
3715                ret = -ENOMEM;
3716                goto failed_mount;
3717        }
3718
3719        if (ext4_proc_root)
3720                sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3721
3722        if (sbi->s_proc)
3723                proc_create_data("options", S_IRUGO, sbi->s_proc,
3724                                 &ext4_seq_options_fops, sb);
3725
3726        bgl_lock_init(sbi->s_blockgroup_lock);
3727
3728        for (i = 0; i < db_count; i++) {
3729                block = descriptor_loc(sb, logical_sb_block, i);
3730                sbi->s_group_desc[i] = sb_bread(sb, block);
3731                if (!sbi->s_group_desc[i]) {
3732                        ext4_msg(sb, KERN_ERR,
3733                               "can't read group descriptor %d", i);
3734                        db_count = i;
3735                        goto failed_mount2;
3736                }
3737        }
3738        if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3739                ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3740                goto failed_mount2;
3741        }
3742        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3743                if (!ext4_fill_flex_info(sb)) {
3744                        ext4_msg(sb, KERN_ERR,
3745                               "unable to initialize "
3746                               "flex_bg meta info!");
3747                        goto failed_mount2;
3748                }
3749
3750        sbi->s_gdb_count = db_count;
3751        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3752        spin_lock_init(&sbi->s_next_gen_lock);
3753
3754        init_timer(&sbi->s_err_report);
3755        sbi->s_err_report.function = print_daily_error_info;
3756        sbi->s_err_report.data = (unsigned long) sb;
3757
3758        err = percpu_counter_init(&sbi->s_freeclusters_counter,
3759                        ext4_count_free_clusters(sb));
3760        if (!err) {
3761                err = percpu_counter_init(&sbi->s_freeinodes_counter,
3762                                ext4_count_free_inodes(sb));
3763        }
3764        if (!err) {
3765                err = percpu_counter_init(&sbi->s_dirs_counter,
3766                                ext4_count_dirs(sb));
3767        }
3768        if (!err) {
3769                err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3770        }
3771        if (err) {
3772                ext4_msg(sb, KERN_ERR, "insufficient memory");
3773                ret = err;
3774                goto failed_mount3;
3775        }
3776
3777        sbi->s_stripe = ext4_get_stripe_size(sbi);
3778        sbi->s_max_writeback_mb_bump = 128;
3779        sbi->s_extent_max_zeroout_kb = 32;
3780
3781        /*
3782         * set up enough so that it can read an inode
3783         */
3784        if (!test_opt(sb, NOLOAD) &&
3785            EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3786                sb->s_op = &ext4_sops;
3787        else
3788                sb->s_op = &ext4_nojournal_sops;
3789        sb->s_export_op = &ext4_export_ops;
3790        sb->s_xattr = ext4_xattr_handlers;
3791#ifdef CONFIG_QUOTA
3792        sb->s_qcop = &ext4_qctl_operations;
3793        sb->dq_op = &ext4_quota_operations;
3794
3795        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3796                /* Use qctl operations for hidden quota files. */
3797                sb->s_qcop = &ext4_qctl_sysfile_operations;
3798        }
3799#endif
3800        memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3801
3802        INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3803        mutex_init(&sbi->s_orphan_lock);
3804        sbi->s_resize_flags = 0;
3805
3806        sb->s_root = NULL;
3807
3808        needs_recovery = (es->s_last_orphan != 0 ||
3809                          EXT4_HAS_INCOMPAT_FEATURE(sb,
3810                                    EXT4_FEATURE_INCOMPAT_RECOVER));
3811
3812        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3813            !(sb->s_flags & MS_RDONLY))
3814                if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3815                        goto failed_mount3;
3816
3817        /*
3818         * The first inode we look at is the journal inode.  Don't try
3819         * root first: it may be modified in the journal!
3820         */
3821        if (!test_opt(sb, NOLOAD) &&
3822            EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3823                if (ext4_load_journal(sb, es, journal_devnum))
3824                        goto failed_mount3;
3825        } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3826              EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3827                ext4_msg(sb, KERN_ERR, "required journal recovery "
3828                       "suppressed and not mounted read-only");
3829                goto failed_mount_wq;
3830        } else {
3831                clear_opt(sb, DATA_FLAGS);
3832                sbi->s_journal = NULL;
3833                needs_recovery = 0;
3834                goto no_journal;
3835        }
3836
3837        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3838            !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3839                                       JBD2_FEATURE_INCOMPAT_64BIT)) {
3840                ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3841                goto failed_mount_wq;
3842        }
3843
3844        if (!set_journal_csum_feature_set(sb)) {
3845                ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3846                         "feature set");
3847                goto failed_mount_wq;
3848        }
3849
3850        /* We have now updated the journal if required, so we can
3851         * validate the data journaling mode. */
3852        switch (test_opt(sb, DATA_FLAGS)) {
3853        case 0:
3854                /* No mode set, assume a default based on the journal
3855                 * capabilities: ORDERED_DATA if the journal can
3856                 * cope, else JOURNAL_DATA
3857                 */
3858                if (jbd2_journal_check_available_features
3859                    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3860                        set_opt(sb, ORDERED_DATA);
3861                else
3862                        set_opt(sb, JOURNAL_DATA);
3863                break;
3864
3865        case EXT4_MOUNT_ORDERED_DATA:
3866        case EXT4_MOUNT_WRITEBACK_DATA:
3867                if (!jbd2_journal_check_available_features
3868                    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3869                        ext4_msg(sb, KERN_ERR, "Journal does not support "
3870                               "requested data journaling mode");
3871                        goto failed_mount_wq;
3872                }
3873        default:
3874                break;
3875        }
3876        set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3877
3878        sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3879
3880        /*
3881         * The journal may have updated the bg summary counts, so we
3882         * need to update the global counters.
3883         */
3884        percpu_counter_set(&sbi->s_freeclusters_counter,
3885                           ext4_count_free_clusters(sb));
3886        percpu_counter_set(&sbi->s_freeinodes_counter,
3887                           ext4_count_free_inodes(sb));
3888        percpu_counter_set(&sbi->s_dirs_counter,
3889                           ext4_count_dirs(sb));
3890        percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3891
3892no_journal:
3893        /*
3894         * Get the # of file system overhead blocks from the
3895         * superblock if present.
3896         */
3897        if (es->s_overhead_clusters)
3898                sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3899        else {
3900                ret = ext4_calculate_overhead(sb);
3901                if (ret)
3902                        goto failed_mount_wq;
3903        }
3904
3905        /*
3906         * The maximum number of concurrent works can be high and
3907         * concurrency isn't really necessary.  Limit it to 1.
3908         */
3909        EXT4_SB(sb)->dio_unwritten_wq =
3910                alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3911        if (!EXT4_SB(sb)->dio_unwritten_wq) {
3912                printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3913                goto failed_mount_wq;
3914        }
3915
3916        /*
3917         * The jbd2_journal_load will have done any necessary log recovery,
3918         * so we can safely mount the rest of the filesystem now.
3919         */
3920
3921        root = ext4_iget(sb, EXT4_ROOT_INO);
3922        if (IS_ERR(root)) {
3923                ext4_msg(sb, KERN_ERR, "get root inode failed");
3924                ret = PTR_ERR(root);
3925                root = NULL;
3926                goto failed_mount4;
3927        }
3928        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3929                ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3930                iput(root);
3931                goto failed_mount4;
3932        }
3933        sb->s_root = d_make_root(root);
3934        if (!sb->s_root) {
3935                ext4_msg(sb, KERN_ERR, "get root dentry failed");
3936                ret = -ENOMEM;
3937                goto failed_mount4;
3938        }
3939
3940        if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3941                sb->s_flags |= MS_RDONLY;
3942
3943        /* determine the minimum size of new large inodes, if present */
3944        if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3945                sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3946                                                     EXT4_GOOD_OLD_INODE_SIZE;
3947                if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3948                                       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3949                        if (sbi->s_want_extra_isize <
3950                            le16_to_cpu(es->s_want_extra_isize))
3951                                sbi->s_want_extra_isize =
3952                                        le16_to_cpu(es->s_want_extra_isize);
3953                        if (sbi->s_want_extra_isize <
3954                            le16_to_cpu(es->s_min_extra_isize))
3955                                sbi->s_want_extra_isize =
3956                                        le16_to_cpu(es->s_min_extra_isize);
3957                }
3958        }
3959        /* Check if enough inode space is available */
3960        if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3961                                                        sbi->s_inode_size) {
3962                sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3963                                                       EXT4_GOOD_OLD_INODE_SIZE;
3964                ext4_msg(sb, KERN_INFO, "required extra inode space not"
3965                         "available");
3966        }
3967
3968        err = ext4_setup_system_zone(sb);
3969        if (err) {
3970                ext4_msg(sb, KERN_ERR, "failed to initialize system "
3971                         "zone (%d)", err);
3972                goto failed_mount4a;
3973        }
3974
3975        ext4_ext_init(sb);
3976        err = ext4_mb_init(sb);
3977        if (err) {
3978                ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3979                         err);
3980                goto failed_mount5;
3981        }
3982
3983        err = ext4_register_li_request(sb, first_not_zeroed);
3984        if (err)
3985                goto failed_mount6;
3986
3987        sbi->s_kobj.kset = ext4_kset;
3988        init_completion(&sbi->s_kobj_unregister);
3989        err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3990                                   "%s", sb->s_id);
3991        if (err)
3992                goto failed_mount7;
3993
3994        EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3995        ext4_orphan_cleanup(sb, es);
3996        EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3997        if (needs_recovery) {
3998                ext4_msg(sb, KERN_INFO, "recovery complete");
3999                ext4_mark_recovery_complete(sb, es);
4000        }
4001        if (EXT4_SB(sb)->s_journal) {
4002                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4003                        descr = " journalled data mode";
4004                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4005                        descr = " ordered data mode";
4006                else
4007                        descr = " writeback data mode";
4008        } else
4009                descr = "out journal";
4010
4011#ifdef CONFIG_QUOTA
4012        /* Enable quota usage during mount. */
4013        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4014            !(sb->s_flags & MS_RDONLY)) {
4015                ret = ext4_enable_quotas(sb);
4016                if (ret)
4017                        goto failed_mount7;
4018        }
4019#endif  /* CONFIG_QUOTA */
4020
4021        ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4022                 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4023                 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4024
4025        if (es->s_error_count)
4026                mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4027
4028        kfree(orig_data);
4029        return 0;
4030
4031cantfind_ext4:
4032        if (!silent)
4033                ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4034        goto failed_mount;
4035
4036failed_mount7:
4037        ext4_unregister_li_request(sb);
4038failed_mount6:
4039        ext4_mb_release(sb);
4040failed_mount5:
4041        ext4_ext_release(sb);
4042        ext4_release_system_zone(sb);
4043failed_mount4a:
4044        dput(sb->s_root);
4045        sb->s_root = NULL;
4046failed_mount4:
4047        ext4_msg(sb, KERN_ERR, "mount failed");
4048        destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4049failed_mount_wq:
4050        if (sbi->s_journal) {
4051                jbd2_journal_destroy(sbi->s_journal);
4052                sbi->s_journal = NULL;
4053        }
4054failed_mount3:
4055        del_timer(&sbi->s_err_report);
4056        if (sbi->s_flex_groups)
4057                ext4_kvfree(sbi->s_flex_groups);
4058        percpu_counter_destroy(&sbi->s_freeclusters_counter);
4059        percpu_counter_destroy(&sbi->s_freeinodes_counter);
4060        percpu_counter_destroy(&sbi->s_dirs_counter);
4061        percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4062        if (sbi->s_mmp_tsk)
4063                kthread_stop(sbi->s_mmp_tsk);
4064failed_mount2:
4065        for (i = 0; i < db_count; i++)
4066                brelse(sbi->s_group_desc[i]);
4067        ext4_kvfree(sbi->s_group_desc);
4068failed_mount:
4069        if (sbi->s_chksum_driver)
4070                crypto_free_shash(sbi->s_chksum_driver);
4071        if (sbi->s_proc) {
4072                remove_proc_entry("options", sbi->s_proc);
4073                remove_proc_entry(sb->s_id, ext4_proc_root);
4074        }
4075#ifdef CONFIG_QUOTA
4076        for (i = 0; i < MAXQUOTAS; i++)
4077                kfree(sbi->s_qf_names[i]);
4078#endif
4079        ext4_blkdev_remove(sbi);
4080        brelse(bh);
4081out_fail:
4082        sb->s_fs_info = NULL;
4083        kfree(sbi->s_blockgroup_lock);
4084        kfree(sbi);
4085out_free_orig:
4086        kfree(orig_data);
4087        return ret;
4088}
4089
4090/*
4091 * Setup any per-fs journal parameters now.  We'll do this both on
4092 * initial mount, once the journal has been initialised but before we've
4093 * done any recovery; and again on any subsequent remount.
4094 */
4095static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4096{
4097        struct ext4_sb_info *sbi = EXT4_SB(sb);
4098
4099        journal->j_commit_interval = sbi->s_commit_interval;
4100        journal->j_min_batch_time = sbi->s_min_batch_time;
4101        journal->j_max_batch_time = sbi->s_max_batch_time;
4102
4103        write_lock(&journal->j_state_lock);
4104        if (test_opt(sb, BARRIER))
4105                journal->j_flags |= JBD2_BARRIER;
4106        else
4107                journal->j_flags &= ~JBD2_BARRIER;
4108        if (test_opt(sb, DATA_ERR_ABORT))
4109                journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4110        else
4111                journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4112        write_unlock(&journal->j_state_lock);
4113}
4114
4115static journal_t *ext4_get_journal(struct super_block *sb,
4116                                   unsigned int journal_inum)
4117{
4118        struct inode *journal_inode;
4119        journal_t *journal;
4120
4121        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4122
4123        /* First, test for the existence of a valid inode on disk.  Bad
4124         * things happen if we iget() an unused inode, as the subsequent
4125         * iput() will try to delete it. */
4126
4127        journal_inode = ext4_iget(sb, journal_inum);
4128        if (IS_ERR(journal_inode)) {
4129                ext4_msg(sb, KERN_ERR, "no journal found");
4130                return NULL;
4131        }
4132        if (!journal_inode->i_nlink) {
4133                make_bad_inode(journal_inode);
4134                iput(journal_inode);
4135                ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4136                return NULL;
4137        }
4138
4139        jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4140                  journal_inode, journal_inode->i_size);
4141        if (!S_ISREG(journal_inode->i_mode)) {
4142                ext4_msg(sb, KERN_ERR, "invalid journal inode");
4143                iput(journal_inode);
4144                return NULL;
4145        }
4146
4147        journal = jbd2_journal_init_inode(journal_inode);
4148        if (!journal) {
4149                ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4150                iput(journal_inode);
4151                return NULL;
4152        }
4153        journal->j_private = sb;
4154        ext4_init_journal_params(sb, journal);
4155        return journal;
4156}
4157
4158static journal_t *ext4_get_dev_journal(struct super_block *sb,
4159                                       dev_t j_dev)
4160{
4161        struct buffer_head *bh;
4162        journal_t *journal;
4163        ext4_fsblk_t start;
4164        ext4_fsblk_t len;
4165        int hblock, blocksize;
4166        ext4_fsblk_t sb_block;
4167        unsigned long offset;
4168        struct ext4_super_block *es;
4169        struct block_device *bdev;
4170
4171        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4172
4173        bdev = ext4_blkdev_get(j_dev, sb);
4174        if (bdev == NULL)
4175                return NULL;
4176
4177        blocksize = sb->s_blocksize;
4178        hblock = bdev_logical_block_size(bdev);
4179        if (blocksize < hblock) {
4180                ext4_msg(sb, KERN_ERR,
4181                        "blocksize too small for journal device");
4182                goto out_bdev;
4183        }
4184
4185        sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4186        offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4187        set_blocksize(bdev, blocksize);
4188        if (!(bh = __bread(bdev, sb_block, blocksize))) {
4189                ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4190                       "external journal");
4191                goto out_bdev;
4192        }
4193
4194        es = (struct ext4_super_block *) (bh->b_data + offset);
4195        if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4196            !(le32_to_cpu(es->s_feature_incompat) &
4197              EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4198                ext4_msg(sb, KERN_ERR, "external journal has "
4199                                        "bad superblock");
4200                brelse(bh);
4201                goto out_bdev;
4202        }
4203
4204        if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4205                ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4206                brelse(bh);
4207                goto out_bdev;
4208        }
4209
4210        len = ext4_blocks_count(es);
4211        start = sb_block + 1;
4212        brelse(bh);     /* we're done with the superblock */
4213
4214        journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4215                                        start, len, blocksize);
4216        if (!journal) {
4217                ext4_msg(sb, KERN_ERR, "failed to create device journal");
4218                goto out_bdev;
4219        }
4220        journal->j_private = sb;
4221        ll_rw_block(READ, 1, &journal->j_sb_buffer);
4222        wait_on_buffer(journal->j_sb_buffer);
4223        if (!buffer_uptodate(journal->j_sb_buffer)) {
4224                ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4225                goto out_journal;
4226        }
4227        if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4228                ext4_msg(sb, KERN_ERR, "External journal has more than one "
4229                                        "user (unsupported) - %d",
4230                        be32_to_cpu(journal->j_superblock->s_nr_users));
4231                goto out_journal;
4232        }
4233        EXT4_SB(sb)->journal_bdev = bdev;
4234        ext4_init_journal_params(sb, journal);
4235        return journal;
4236
4237out_journal:
4238        jbd2_journal_destroy(journal);
4239out_bdev:
4240        ext4_blkdev_put(bdev);
4241        return NULL;
4242}
4243
4244static int ext4_load_journal(struct super_block *sb,
4245                             struct ext4_super_block *es,
4246                             unsigned long journal_devnum)
4247{
4248        journal_t *journal;
4249        unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4250        dev_t journal_dev;
4251        int err = 0;
4252        int really_read_only;
4253
4254        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4255
4256        if (journal_devnum &&
4257            journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4258                ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4259                        "numbers have changed");
4260                journal_dev = new_decode_dev(journal_devnum);
4261        } else
4262                journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4263
4264        really_read_only = bdev_read_only(sb->s_bdev);
4265
4266        /*
4267         * Are we loading a blank journal or performing recovery after a
4268         * crash?  For recovery, we need to check in advance whether we
4269         * can get read-write access to the device.
4270         */
4271        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4272                if (sb->s_flags & MS_RDONLY) {
4273                        ext4_msg(sb, KERN_INFO, "INFO: recovery "
4274                                        "required on readonly filesystem");
4275                        if (really_read_only) {
4276                                ext4_msg(sb, KERN_ERR, "write access "
4277                                        "unavailable, cannot proceed");
4278                                return -EROFS;
4279                        }
4280                        ext4_msg(sb, KERN_INFO, "write access will "
4281                               "be enabled during recovery");
4282                }
4283        }
4284
4285        if (journal_inum && journal_dev) {
4286                ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4287                       "and inode journals!");
4288                return -EINVAL;
4289        }
4290
4291        if (journal_inum) {
4292                if (!(journal = ext4_get_journal(sb, journal_inum)))
4293                        return -EINVAL;
4294        } else {
4295                if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4296                        return -EINVAL;
4297        }
4298
4299        if (!(journal->j_flags & JBD2_BARRIER))
4300                ext4_msg(sb, KERN_INFO, "barriers disabled");
4301
4302        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4303                err = jbd2_journal_wipe(journal, !really_read_only);
4304        if (!err) {
4305                char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4306                if (save)
4307                        memcpy(save, ((char *) es) +
4308                               EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4309                err = jbd2_journal_load(journal);
4310                if (save)
4311                        memcpy(((char *) es) + EXT4_S_ERR_START,
4312                               save, EXT4_S_ERR_LEN);
4313                kfree(save);
4314        }
4315
4316        if (err) {
4317                ext4_msg(sb, KERN_ERR, "error loading journal");
4318                jbd2_journal_destroy(journal);
4319                return err;
4320        }
4321
4322        EXT4_SB(sb)->s_journal = journal;
4323        ext4_clear_journal_err(sb, es);
4324
4325        if (!really_read_only && journal_devnum &&
4326            journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4327                es->s_journal_dev = cpu_to_le32(journal_devnum);
4328
4329                /* Make sure we flush the recovery flag to disk. */
4330                ext4_commit_super(sb, 1);
4331        }
4332
4333        return 0;
4334}
4335
4336static int ext4_commit_super(struct super_block *sb, int sync)
4337{
4338        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4339        struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4340        int error = 0;
4341
4342        if (!sbh || block_device_ejected(sb))
4343                return error;
4344        if (buffer_write_io_error(sbh)) {
4345                /*
4346                 * Oh, dear.  A previous attempt to write the
4347                 * superblock failed.  This could happen because the
4348                 * USB device was yanked out.  Or it could happen to
4349                 * be a transient write error and maybe the block will
4350                 * be remapped.  Nothing we can do but to retry the
4351                 * write and hope for the best.
4352                 */
4353                ext4_msg(sb, KERN_ERR, "previous I/O error to "
4354                       "superblock detected");
4355                clear_buffer_write_io_error(sbh);
4356                set_buffer_uptodate(sbh);
4357        }
4358        /*
4359         * If the file system is mounted read-only, don't update the
4360         * superblock write time.  This avoids updating the superblock
4361         * write time when we are mounting the root file system
4362         * read/only but we need to replay the journal; at that point,
4363         * for people who are east of GMT and who make their clock
4364         * tick in localtime for Windows bug-for-bug compatibility,
4365         * the clock is set in the future, and this will cause e2fsck
4366         * to complain and force a full file system check.
4367         */
4368        if (!(sb->s_flags & MS_RDONLY))
4369                es->s_wtime = cpu_to_le32(get_seconds());
4370        if (sb->s_bdev->bd_part)
4371                es->s_kbytes_written =
4372                        cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4373                            ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4374                              EXT4_SB(sb)->s_sectors_written_start) >> 1));
4375        else
4376                es->s_kbytes_written =
4377                        cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4378        ext4_free_blocks_count_set(es,
4379                        EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4380                                &EXT4_SB(sb)->s_freeclusters_counter)));
4381        es->s_free_inodes_count =
4382                cpu_to_le32(percpu_counter_sum_positive(
4383                                &EXT4_SB(sb)->s_freeinodes_counter));
4384        BUFFER_TRACE(sbh, "marking dirty");
4385        ext4_superblock_csum_set(sb);
4386        mark_buffer_dirty(sbh);
4387        if (sync) {
4388                error = sync_dirty_buffer(sbh);
4389                if (error)
4390                        return error;
4391
4392                error = buffer_write_io_error(sbh);
4393                if (error) {
4394                        ext4_msg(sb, KERN_ERR, "I/O error while writing "
4395                               "superblock");
4396                        clear_buffer_write_io_error(sbh);
4397                        set_buffer_uptodate(sbh);
4398                }
4399        }
4400        return error;
4401}
4402
4403/*
4404 * Have we just finished recovery?  If so, and if we are mounting (or
4405 * remounting) the filesystem readonly, then we will end up with a
4406 * consistent fs on disk.  Record that fact.
4407 */
4408static void ext4_mark_recovery_complete(struct super_block *sb,
4409                                        struct ext4_super_block *es)
4410{
4411        journal_t *journal = EXT4_SB(sb)->s_journal;
4412
4413        if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4414                BUG_ON(journal != NULL);
4415                return;
4416        }
4417        jbd2_journal_lock_updates(journal);
4418        if (jbd2_journal_flush(journal) < 0)
4419                goto out;
4420
4421        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4422            sb->s_flags & MS_RDONLY) {
4423                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4424                ext4_commit_super(sb, 1);
4425        }
4426
4427out:
4428        jbd2_journal_unlock_updates(journal);
4429}
4430
4431/*
4432 * If we are mounting (or read-write remounting) a filesystem whose journal
4433 * has recorded an error from a previous lifetime, move that error to the
4434 * main filesystem now.
4435 */
4436static void ext4_clear_journal_err(struct super_block *sb,
4437                                   struct ext4_super_block *es)
4438{
4439        journal_t *journal;
4440        int j_errno;
4441        const char *errstr;
4442
4443        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4444
4445        journal = EXT4_SB(sb)->s_journal;
4446
4447        /*
4448         * Now check for any error status which may have been recorded in the
4449         * journal by a prior ext4_error() or ext4_abort()
4450         */
4451
4452        j_errno = jbd2_journal_errno(journal);
4453        if (j_errno) {
4454                char nbuf[16];
4455
4456                errstr = ext4_decode_error(sb, j_errno, nbuf);
4457                ext4_warning(sb, "Filesystem error recorded "
4458                             "from previous mount: %s", errstr);
4459                ext4_warning(sb, "Marking fs in need of filesystem check.");
4460
4461                EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4462                es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4463                ext4_commit_super(sb, 1);
4464
4465                jbd2_journal_clear_err(journal);
4466                jbd2_journal_update_sb_errno(journal);
4467        }
4468}
4469
4470/*
4471 * Force the running and committing transactions to commit,
4472 * and wait on the commit.
4473 */
4474int ext4_force_commit(struct super_block *sb)
4475{
4476        journal_t *journal;
4477        int ret = 0;
4478
4479        if (sb->s_flags & MS_RDONLY)
4480                return 0;
4481
4482        journal = EXT4_SB(sb)->s_journal;
4483        if (journal)
4484                ret = ext4_journal_force_commit(journal);
4485
4486        return ret;
4487}
4488
4489static int ext4_sync_fs(struct super_block *sb, int wait)
4490{
4491        int ret = 0;
4492        tid_t target;
4493        struct ext4_sb_info *sbi = EXT4_SB(sb);
4494
4495        trace_ext4_sync_fs(sb, wait);
4496        flush_workqueue(sbi->dio_unwritten_wq);
4497        /*
4498         * Writeback quota in non-journalled quota case - journalled quota has
4499         * no dirty dquots
4500         */
4501        dquot_writeback_dquots(sb, -1);
4502        if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4503                if (wait)
4504                        jbd2_log_wait_commit(sbi->s_journal, target);
4505        }
4506        return ret;
4507}
4508
4509/*
4510 * LVM calls this function before a (read-only) snapshot is created.  This
4511 * gives us a chance to flush the journal completely and mark the fs clean.
4512 *
4513 * Note that only this function cannot bring a filesystem to be in a clean
4514 * state independently. It relies on upper layer to stop all data & metadata
4515 * modifications.
4516 */
4517static int ext4_freeze(struct super_block *sb)
4518{
4519        int error = 0;
4520        journal_t *journal;
4521
4522        if (sb->s_flags & MS_RDONLY)
4523                return 0;
4524
4525        journal = EXT4_SB(sb)->s_journal;
4526
4527        /* Now we set up the journal barrier. */
4528        jbd2_journal_lock_updates(journal);
4529
4530        /*
4531         * Don't clear the needs_recovery flag if we failed to flush
4532         * the journal.
4533         */
4534        error = jbd2_journal_flush(journal);
4535        if (error < 0)
4536                goto out;
4537
4538        /* Journal blocked and flushed, clear needs_recovery flag. */
4539        EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4540        error = ext4_commit_super(sb, 1);
4541out:
4542        /* we rely on upper layer to stop further updates */
4543        jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4544        return error;
4545}
4546
4547/*
4548 * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4549 * flag here, even though the filesystem is not technically dirty yet.
4550 */
4551static int ext4_unfreeze(struct super_block *sb)
4552{
4553        if (sb->s_flags & MS_RDONLY)
4554                return 0;
4555
4556        /* Reset the needs_recovery flag before the fs is unlocked. */
4557        EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4558        ext4_commit_super(sb, 1);
4559        return 0;
4560}
4561
4562/*
4563 * Structure to save mount options for ext4_remount's benefit
4564 */
4565struct ext4_mount_options {
4566        unsigned long s_mount_opt;
4567        unsigned long s_mount_opt2;
4568        kuid_t s_resuid;
4569        kgid_t s_resgid;
4570        unsigned long s_commit_interval;
4571        u32 s_min_batch_time, s_max_batch_time;
4572#ifdef CONFIG_QUOTA
4573        int s_jquota_fmt;
4574        char *s_qf_names[MAXQUOTAS];
4575#endif
4576};
4577
4578static int ext4_remount(struct super_block *sb, int *flags, char *data)
4579{
4580        struct ext4_super_block *es;
4581        struct ext4_sb_info *sbi = EXT4_SB(sb);
4582        unsigned long old_sb_flags;
4583        struct ext4_mount_options old_opts;
4584        int enable_quota = 0;
4585        ext4_group_t g;
4586        unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4587        int err = 0;
4588#ifdef CONFIG_QUOTA
4589        int i;
4590#endif
4591        char *orig_data = kstrdup(data, GFP_KERNEL);
4592
4593        /* Store the original options */
4594        old_sb_flags = sb->s_flags;
4595        old_opts.s_mount_opt = sbi->s_mount_opt;
4596        old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4597        old_opts.s_resuid = sbi->s_resuid;
4598        old_opts.s_resgid = sbi->s_resgid;
4599        old_opts.s_commit_interval = sbi->s_commit_interval;
4600        old_opts.s_min_batch_time = sbi->s_min_batch_time;
4601        old_opts.s_max_batch_time = sbi->s_max_batch_time;
4602#ifdef CONFIG_QUOTA
4603        old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4604        for (i = 0; i < MAXQUOTAS; i++)
4605                old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4606#endif
4607        if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4608                journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4609
4610        /*
4611         * Allow the "check" option to be passed as a remount option.
4612         */
4613        if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4614                err = -EINVAL;
4615                goto restore_opts;
4616        }
4617
4618        if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4619                ext4_abort(sb, "Abort forced by user");
4620
4621        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4622                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4623
4624        es = sbi->s_es;
4625
4626        if (sbi->s_journal) {
4627                ext4_init_journal_params(sb, sbi->s_journal);
4628                set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4629        }
4630
4631        if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4632                if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4633                        err = -EROFS;
4634                        goto restore_opts;
4635                }
4636
4637                if (*flags & MS_RDONLY) {
4638                        err = dquot_suspend(sb, -1);
4639                        if (err < 0)
4640                                goto restore_opts;
4641
4642                        /*
4643                         * First of all, the unconditional stuff we have to do
4644                         * to disable replay of the journal when we next remount
4645                         */
4646                        sb->s_flags |= MS_RDONLY;
4647
4648                        /*
4649                         * OK, test if we are remounting a valid rw partition
4650                         * readonly, and if so set the rdonly flag and then
4651                         * mark the partition as valid again.
4652                         */
4653                        if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4654                            (sbi->s_mount_state & EXT4_VALID_FS))
4655                                es->s_state = cpu_to_le16(sbi->s_mount_state);
4656
4657                        if (sbi->s_journal)
4658                                ext4_mark_recovery_complete(sb, es);
4659                } else {
4660                        /* Make sure we can mount this feature set readwrite */
4661                        if (!ext4_feature_set_ok(sb, 0)) {
4662                                err = -EROFS;
4663                                goto restore_opts;
4664                        }
4665                        /*
4666                         * Make sure the group descriptor checksums
4667                         * are sane.  If they aren't, refuse to remount r/w.
4668                         */
4669                        for (g = 0; g < sbi->s_groups_count; g++) {
4670                                struct ext4_group_desc *gdp =
4671                                        ext4_get_group_desc(sb, g, NULL);
4672
4673                                if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4674                                        ext4_msg(sb, KERN_ERR,
4675               "ext4_remount: Checksum for group %u failed (%u!=%u)",
4676                g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4677                                               le16_to_cpu(gdp->bg_checksum));
4678                                        err = -EINVAL;
4679                                        goto restore_opts;
4680                                }
4681                        }
4682
4683                        /*
4684                         * If we have an unprocessed orphan list hanging
4685                         * around from a previously readonly bdev mount,
4686                         * require a full umount/remount for now.
4687                         */
4688                        if (es->s_last_orphan) {
4689                                ext4_msg(sb, KERN_WARNING, "Couldn't "
4690                                       "remount RDWR because of unprocessed "
4691                                       "orphan inode list.  Please "
4692                                       "umount/remount instead");
4693                                err = -EINVAL;
4694                                goto restore_opts;
4695                        }
4696
4697                        /*
4698                         * Mounting a RDONLY partition read-write, so reread
4699                         * and store the current valid flag.  (It may have
4700                         * been changed by e2fsck since we originally mounted
4701                         * the partition.)
4702                         */
4703                        if (sbi->s_journal)
4704                                ext4_clear_journal_err(sb, es);
4705                        sbi->s_mount_state = le16_to_cpu(es->s_state);
4706                        if (!ext4_setup_super(sb, es, 0))
4707                                sb->s_flags &= ~MS_RDONLY;
4708                        if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4709                                                     EXT4_FEATURE_INCOMPAT_MMP))
4710                                if (ext4_multi_mount_protect(sb,
4711                                                le64_to_cpu(es->s_mmp_block))) {
4712                                        err = -EROFS;
4713                                        goto restore_opts;
4714                                }
4715                        enable_quota = 1;
4716                }
4717        }
4718
4719        /*
4720         * Reinitialize lazy itable initialization thread based on
4721         * current settings
4722         */
4723        if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4724                ext4_unregister_li_request(sb);
4725        else {
4726                ext4_group_t first_not_zeroed;
4727                first_not_zeroed = ext4_has_uninit_itable(sb);
4728                ext4_register_li_request(sb, first_not_zeroed);
4729        }
4730
4731        ext4_setup_system_zone(sb);
4732        if (sbi->s_journal == NULL)
4733                ext4_commit_super(sb, 1);
4734
4735#ifdef CONFIG_QUOTA
4736        /* Release old quota file names */
4737        for (i = 0; i < MAXQUOTAS; i++)
4738                if (old_opts.s_qf_names[i] &&
4739                    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4740                        kfree(old_opts.s_qf_names[i]);
4741        if (enable_quota) {
4742                if (sb_any_quota_suspended(sb))
4743                        dquot_resume(sb, -1);
4744                else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4745                                        EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4746                        err = ext4_enable_quotas(sb);
4747                        if (err)
4748                                goto restore_opts;
4749                }
4750        }
4751#endif
4752
4753        ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4754        kfree(orig_data);
4755        return 0;
4756
4757restore_opts:
4758        sb->s_flags = old_sb_flags;
4759        sbi->s_mount_opt = old_opts.s_mount_opt;
4760        sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4761        sbi->s_resuid = old_opts.s_resuid;
4762        sbi->s_resgid = old_opts.s_resgid;
4763        sbi->s_commit_interval = old_opts.s_commit_interval;
4764        sbi->s_min_batch_time = old_opts.s_min_batch_time;
4765        sbi->s_max_batch_time = old_opts.s_max_batch_time;
4766#ifdef CONFIG_QUOTA
4767        sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4768        for (i = 0; i < MAXQUOTAS; i++) {
4769                if (sbi->s_qf_names[i] &&
4770                    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4771                        kfree(sbi->s_qf_names[i]);
4772                sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4773        }
4774#endif
4775        kfree(orig_data);
4776        return err;
4777}
4778
4779static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4780{
4781        struct super_block *sb = dentry->d_sb;
4782        struct ext4_sb_info *sbi = EXT4_SB(sb);
4783        struct ext4_super_block *es = sbi->s_es;
4784        ext4_fsblk_t overhead = 0;
4785        u64 fsid;
4786        s64 bfree;
4787
4788        if (!test_opt(sb, MINIX_DF))
4789                overhead = sbi->s_overhead;
4790
4791        buf->f_type = EXT4_SUPER_MAGIC;
4792        buf->f_bsize = sb->s_blocksize;
4793        buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
4794        bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4795                percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4796        /* prevent underflow in case that few free space is available */
4797        buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4798        buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4799        if (buf->f_bfree < ext4_r_blocks_count(es))
4800                buf->f_bavail = 0;
4801        buf->f_files = le32_to_cpu(es->s_inodes_count);
4802        buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4803        buf->f_namelen = EXT4_NAME_LEN;
4804        fsid = le64_to_cpup((void *)es->s_uuid) ^
4805               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4806        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4807        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4808
4809        return 0;
4810}
4811
4812/* Helper function for writing quotas on sync - we need to start transaction
4813 * before quota file is locked for write. Otherwise the are possible deadlocks:
4814 * Process 1                         Process 2
4815 * ext4_create()                     quota_sync()
4816 *   jbd2_journal_start()                  write_dquot()
4817 *   dquot_initialize()                         down(dqio_mutex)
4818 *     down(dqio_mutex)                    jbd2_journal_start()
4819 *
4820 */
4821
4822#ifdef CONFIG_QUOTA
4823
4824static inline struct inode *dquot_to_inode(struct dquot *dquot)
4825{
4826        return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4827}
4828
4829static int ext4_write_dquot(struct dquot *dquot)
4830{
4831        int ret, err;
4832        handle_t *handle;
4833        struct inode *inode;
4834
4835        inode = dquot_to_inode(dquot);
4836        handle = ext4_journal_start(inode,
4837                                    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4838        if (IS_ERR(handle))
4839                return PTR_ERR(handle);
4840        ret = dquot_commit(dquot);
4841        err = ext4_journal_stop(handle);
4842        if (!ret)
4843                ret = err;
4844        return ret;
4845}
4846
4847static int ext4_acquire_dquot(struct dquot *dquot)
4848{
4849        int ret, err;
4850        handle_t *handle;
4851
4852        handle = ext4_journal_start(dquot_to_inode(dquot),
4853                                    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4854        if (IS_ERR(handle))
4855                return PTR_ERR(handle);
4856        ret = dquot_acquire(dquot);
4857        err = ext4_journal_stop(handle);
4858        if (!ret)
4859                ret = err;
4860        return ret;
4861}
4862
4863static int ext4_release_dquot(struct dquot *dquot)
4864{
4865        int ret, err;
4866        handle_t *handle;
4867
4868        handle = ext4_journal_start(dquot_to_inode(dquot),
4869                                    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4870        if (IS_ERR(handle)) {
4871                /* Release dquot anyway to avoid endless cycle in dqput() */
4872                dquot_release(dquot);
4873                return PTR_ERR(handle);
4874        }
4875        ret = dquot_release(dquot);
4876        err = ext4_journal_stop(handle);
4877        if (!ret)
4878                ret = err;
4879        return ret;
4880}
4881
4882static int ext4_mark_dquot_dirty(struct dquot *dquot)
4883{
4884        /* Are we journaling quotas? */
4885        if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4886            EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4887                dquot_mark_dquot_dirty(dquot);
4888                return ext4_write_dquot(dquot);
4889        } else {
4890                return dquot_mark_dquot_dirty(dquot);
4891        }
4892}
4893
4894static int ext4_write_info(struct super_block *sb, int type)
4895{
4896        int ret, err;
4897        handle_t *handle;
4898
4899        /* Data block + inode block */
4900        handle = ext4_journal_start(sb->s_root->d_inode, 2);
4901        if (IS_ERR(handle))
4902                return PTR_ERR(handle);
4903        ret = dquot_commit_info(sb, type);
4904        err = ext4_journal_stop(handle);
4905        if (!ret)
4906                ret = err;
4907        return ret;
4908}
4909
4910/*
4911 * Turn on quotas during mount time - we need to find
4912 * the quota file and such...
4913 */
4914static int ext4_quota_on_mount(struct super_block *sb, int type)
4915{
4916        return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4917                                        EXT4_SB(sb)->s_jquota_fmt, type);
4918}
4919
4920/*
4921 * Standard function to be called on quota_on
4922 */
4923static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4924                         struct path *path)
4925{
4926        int err;
4927
4928        if (!test_opt(sb, QUOTA))
4929                return -EINVAL;
4930
4931        /* Quotafile not on the same filesystem? */
4932        if (path->dentry->d_sb != sb)
4933                return -EXDEV;
4934        /* Journaling quota? */
4935        if (EXT4_SB(sb)->s_qf_names[type]) {
4936                /* Quotafile not in fs root? */
4937                if (path->dentry->d_parent != sb->s_root)
4938                        ext4_msg(sb, KERN_WARNING,
4939                                "Quota file not on filesystem root. "
4940                                "Journaled quota will not work");
4941        }
4942
4943        /*
4944         * When we journal data on quota file, we have to flush journal to see
4945         * all updates to the file when we bypass pagecache...
4946         */
4947        if (EXT4_SB(sb)->s_journal &&
4948            ext4_should_journal_data(path->dentry->d_inode)) {
4949                /*
4950                 * We don't need to lock updates but journal_flush() could
4951                 * otherwise be livelocked...
4952                 */
4953                jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4954                err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4955                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4956                if (err)
4957                        return err;
4958        }
4959
4960        return dquot_quota_on(sb, type, format_id, path);
4961}
4962
4963static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4964                             unsigned int flags)
4965{
4966        int err;
4967        struct inode *qf_inode;
4968        unsigned long qf_inums[MAXQUOTAS] = {
4969                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4970                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4971        };
4972
4973        BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4974
4975        if (!qf_inums[type])
4976                return -EPERM;
4977
4978        qf_inode = ext4_iget(sb, qf_inums[type]);
4979        if (IS_ERR(qf_inode)) {
4980                ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4981                return PTR_ERR(qf_inode);
4982        }
4983
4984        err = dquot_enable(qf_inode, type, format_id, flags);
4985        iput(qf_inode);
4986
4987        return err;
4988}
4989
4990/* Enable usage tracking for all quota types. */
4991static int ext4_enable_quotas(struct super_block *sb)
4992{
4993        int type, err = 0;
4994        unsigned long qf_inums[MAXQUOTAS] = {
4995                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4996                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4997        };
4998
4999        sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5000        for (type = 0; type < MAXQUOTAS; type++) {
5001                if (qf_inums[type]) {
5002                        err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5003                                                DQUOT_USAGE_ENABLED);
5004                        if (err) {
5005                                ext4_warning(sb,
5006                                        "Failed to enable quota (type=%d) "
5007                                        "tracking. Please run e2fsck to fix.",
5008                                        type);
5009                                return err;
5010                        }
5011                }
5012        }
5013        return 0;
5014}
5015
5016/*
5017 * quota_on function that is used when QUOTA feature is set.
5018 */
5019static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5020                                 int format_id)
5021{
5022        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5023                return -EINVAL;
5024
5025        /*
5026         * USAGE was enabled at mount time. Only need to enable LIMITS now.
5027         */
5028        return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5029}
5030
5031static int ext4_quota_off(struct super_block *sb, int type)
5032{
5033        struct inode *inode = sb_dqopt(sb)->files[type];
5034        handle_t *handle;
5035
5036        /* Force all delayed allocation blocks to be allocated.
5037         * Caller already holds s_umount sem */
5038        if (test_opt(sb, DELALLOC))
5039                sync_filesystem(sb);
5040
5041        if (!inode)
5042                goto out;
5043
5044        /* Update modification times of quota files when userspace can
5045         * start looking at them */
5046        handle = ext4_journal_start(inode, 1);
5047        if (IS_ERR(handle))
5048                goto out;
5049        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5050        ext4_mark_inode_dirty(handle, inode);
5051        ext4_journal_stop(handle);
5052
5053out:
5054        return dquot_quota_off(sb, type);
5055}
5056
5057/*
5058 * quota_off function that is used when QUOTA feature is set.
5059 */
5060static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5061{
5062        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5063                return -EINVAL;
5064
5065        /* Disable only the limits. */
5066        return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5067}
5068
5069/* Read data from quotafile - avoid pagecache and such because we cannot afford
5070 * acquiring the locks... As quota files are never truncated and quota code
5071 * itself serializes the operations (and no one else should touch the files)
5072 * we don't have to be afraid of races */
5073static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5074                               size_t len, loff_t off)
5075{
5076        struct inode *inode = sb_dqopt(sb)->files[type];
5077        ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5078        int err = 0;
5079        int offset = off & (sb->s_blocksize - 1);
5080        int tocopy;
5081        size_t toread;
5082        struct buffer_head *bh;
5083        loff_t i_size = i_size_read(inode);
5084
5085        if (off > i_size)
5086                return 0;
5087        if (off+len > i_size)
5088                len = i_size-off;
5089        toread = len;
5090        while (toread > 0) {
5091                tocopy = sb->s_blocksize - offset < toread ?
5092                                sb->s_blocksize - offset : toread;
5093                bh = ext4_bread(NULL, inode, blk, 0, &err);
5094                if (err)
5095                        return err;
5096                if (!bh)        /* A hole? */
5097                        memset(data, 0, tocopy);
5098                else
5099                        memcpy(data, bh->b_data+offset, tocopy);
5100                brelse(bh);
5101                offset = 0;
5102                toread -= tocopy;
5103                data += tocopy;
5104                blk++;
5105        }
5106        return len;
5107}
5108
5109/* Write to quotafile (we know the transaction is already started and has
5110 * enough credits) */
5111static ssize_t ext4_quota_write(struct super_block *sb, int type,
5112                                const char *data, size_t len, loff_t off)
5113{
5114        struct inode *inode = sb_dqopt(sb)->files[type];
5115        ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5116        int err = 0;
5117        int offset = off & (sb->s_blocksize - 1);
5118        struct buffer_head *bh;
5119        handle_t *handle = journal_current_handle();
5120
5121        if (EXT4_SB(sb)->s_journal && !handle) {
5122                ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5123                        " cancelled because transaction is not started",
5124                        (unsigned long long)off, (unsigned long long)len);
5125                return -EIO;
5126        }
5127        /*
5128         * Since we account only one data block in transaction credits,
5129         * then it is impossible to cross a block boundary.
5130         */
5131        if (sb->s_blocksize - offset < len) {
5132                ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5133                        " cancelled because not block aligned",
5134                        (unsigned long long)off, (unsigned long long)len);
5135                return -EIO;
5136        }
5137
5138        bh = ext4_bread(handle, inode, blk, 1, &