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        es->s_error_count = cpu_to_le32(le32_to_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        lock_super(sb);
 855        if (sbi->s_journal) {
 856                err = jbd2_journal_destroy(sbi->s_journal);
 857                sbi->s_journal = NULL;
 858                if (err < 0)
 859                        ext4_abort(sb, "Couldn't clean up the journal");
 860        }
 861
 862        del_timer(&sbi->s_err_report);
 863        ext4_release_system_zone(sb);
 864        ext4_mb_release(sb);
 865        ext4_ext_release(sb);
 866        ext4_xattr_put_super(sb);
 867
 868        if (!(sb->s_flags & MS_RDONLY)) {
 869                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 870                es->s_state = cpu_to_le16(sbi->s_mount_state);
 871        }
 872        if (!(sb->s_flags & MS_RDONLY))
 873                ext4_commit_super(sb, 1);
 874
 875        if (sbi->s_proc) {
 876                remove_proc_entry("options", sbi->s_proc);
 877                remove_proc_entry(sb->s_id, ext4_proc_root);
 878        }
 879        kobject_del(&sbi->s_kobj);
 880
 881        for (i = 0; i < sbi->s_gdb_count; i++)
 882                brelse(sbi->s_group_desc[i]);
 883        ext4_kvfree(sbi->s_group_desc);
 884        ext4_kvfree(sbi->s_flex_groups);
 885        percpu_counter_destroy(&sbi->s_freeclusters_counter);
 886        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 887        percpu_counter_destroy(&sbi->s_dirs_counter);
 888        percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 889        brelse(sbi->s_sbh);
 890#ifdef CONFIG_QUOTA
 891        for (i = 0; i < MAXQUOTAS; i++)
 892                kfree(sbi->s_qf_names[i]);
 893#endif
 894
 895        /* Debugging code just in case the in-memory inode orphan list
 896         * isn't empty.  The on-disk one can be non-empty if we've
 897         * detected an error and taken the fs readonly, but the
 898         * in-memory list had better be clean by this point. */
 899        if (!list_empty(&sbi->s_orphan))
 900                dump_orphan_list(sb, sbi);
 901        J_ASSERT(list_empty(&sbi->s_orphan));
 902
 903        invalidate_bdev(sb->s_bdev);
 904        if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 905                /*
 906                 * Invalidate the journal device's buffers.  We don't want them
 907                 * floating about in memory - the physical journal device may
 908                 * hotswapped, and it breaks the `ro-after' testing code.
 909                 */
 910                sync_blockdev(sbi->journal_bdev);
 911                invalidate_bdev(sbi->journal_bdev);
 912                ext4_blkdev_remove(sbi);
 913        }
 914        if (sbi->s_mmp_tsk)
 915                kthread_stop(sbi->s_mmp_tsk);
 916        sb->s_fs_info = NULL;
 917        /*
 918         * Now that we are completely done shutting down the
 919         * superblock, we need to actually destroy the kobject.
 920         */
 921        unlock_super(sb);
 922        kobject_put(&sbi->s_kobj);
 923        wait_for_completion(&sbi->s_kobj_unregister);
 924        if (sbi->s_chksum_driver)
 925                crypto_free_shash(sbi->s_chksum_driver);
 926        kfree(sbi->s_blockgroup_lock);
 927        kfree(sbi);
 928}
 929
 930static struct kmem_cache *ext4_inode_cachep;
 931
 932/*
 933 * Called inside transaction, so use GFP_NOFS
 934 */
 935static struct inode *ext4_alloc_inode(struct super_block *sb)
 936{
 937        struct ext4_inode_info *ei;
 938
 939        ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 940        if (!ei)
 941                return NULL;
 942
 943        ei->vfs_inode.i_version = 1;
 944        ei->vfs_inode.i_data.writeback_index = 0;
 945        memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 946        INIT_LIST_HEAD(&ei->i_prealloc_list);
 947        spin_lock_init(&ei->i_prealloc_lock);
 948        ei->i_reserved_data_blocks = 0;
 949        ei->i_reserved_meta_blocks = 0;
 950        ei->i_allocated_meta_blocks = 0;
 951        ei->i_da_metadata_calc_len = 0;
 952        ei->i_da_metadata_calc_last_lblock = 0;
 953        spin_lock_init(&(ei->i_block_reservation_lock));
 954#ifdef CONFIG_QUOTA
 955        ei->i_reserved_quota = 0;
 956#endif
 957        ei->jinode = NULL;
 958        INIT_LIST_HEAD(&ei->i_completed_io_list);
 959        spin_lock_init(&ei->i_completed_io_lock);
 960        ei->cur_aio_dio = NULL;
 961        ei->i_sync_tid = 0;
 962        ei->i_datasync_tid = 0;
 963        atomic_set(&ei->i_ioend_count, 0);
 964        atomic_set(&ei->i_aiodio_unwritten, 0);
 965
 966        return &ei->vfs_inode;
 967}
 968
 969static int ext4_drop_inode(struct inode *inode)
 970{
 971        int drop = generic_drop_inode(inode);
 972
 973        trace_ext4_drop_inode(inode, drop);
 974        return drop;
 975}
 976
 977static void ext4_i_callback(struct rcu_head *head)
 978{
 979        struct inode *inode = container_of(head, struct inode, i_rcu);
 980        kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 981}
 982
 983static void ext4_destroy_inode(struct inode *inode)
 984{
 985        if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 986                ext4_msg(inode->i_sb, KERN_ERR,
 987                         "Inode %lu (%p): orphan list check failed!",
 988                         inode->i_ino, EXT4_I(inode));
 989                print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 990                                EXT4_I(inode), sizeof(struct ext4_inode_info),
 991                                true);
 992                dump_stack();
 993        }
 994        call_rcu(&inode->i_rcu, ext4_i_callback);
 995}
 996
 997static void init_once(void *foo)
 998{
 999        struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1000
1001        INIT_LIST_HEAD(&ei->i_orphan);
1002#ifdef CONFIG_EXT4_FS_XATTR
1003        init_rwsem(&ei->xattr_sem);
1004#endif
1005        init_rwsem(&ei->i_data_sem);
1006        inode_init_once(&ei->vfs_inode);
1007}
1008
1009static int init_inodecache(void)
1010{
1011        ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1012                                             sizeof(struct ext4_inode_info),
1013                                             0, (SLAB_RECLAIM_ACCOUNT|
1014                                                SLAB_MEM_SPREAD),
1015                                             init_once);
1016        if (ext4_inode_cachep == NULL)
1017                return -ENOMEM;
1018        return 0;
1019}
1020
1021static void destroy_inodecache(void)
1022{
1023        kmem_cache_destroy(ext4_inode_cachep);
1024}
1025
1026void ext4_clear_inode(struct inode *inode)
1027{
1028        invalidate_inode_buffers(inode);
1029        clear_inode(inode);
1030        dquot_drop(inode);
1031        ext4_discard_preallocations(inode);
1032        if (EXT4_I(inode)->jinode) {
1033                jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1034                                               EXT4_I(inode)->jinode);
1035                jbd2_free_inode(EXT4_I(inode)->jinode);
1036                EXT4_I(inode)->jinode = NULL;
1037        }
1038}
1039
1040static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1041                                        u64 ino, u32 generation)
1042{
1043        struct inode *inode;
1044
1045        if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1046                return ERR_PTR(-ESTALE);
1047        if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1048                return ERR_PTR(-ESTALE);
1049
1050        /* iget isn't really right if the inode is currently unallocated!!
1051         *
1052         * ext4_read_inode will return a bad_inode if the inode had been
1053         * deleted, so we should be safe.
1054         *
1055         * Currently we don't know the generation for parent directory, so
1056         * a generation of 0 means "accept any"
1057         */
1058        inode = ext4_iget(sb, ino);
1059        if (IS_ERR(inode))
1060                return ERR_CAST(inode);
1061        if (generation && inode->i_generation != generation) {
1062                iput(inode);
1063                return ERR_PTR(-ESTALE);
1064        }
1065
1066        return inode;
1067}
1068
1069static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1070                                        int fh_len, int fh_type)
1071{
1072        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1073                                    ext4_nfs_get_inode);
1074}
1075
1076static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1077                                        int fh_len, int fh_type)
1078{
1079        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1080                                    ext4_nfs_get_inode);
1081}
1082
1083/*
1084 * Try to release metadata pages (indirect blocks, directories) which are
1085 * mapped via the block device.  Since these pages could have journal heads
1086 * which would prevent try_to_free_buffers() from freeing them, we must use
1087 * jbd2 layer's try_to_free_buffers() function to release them.
1088 */
1089static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1090                                 gfp_t wait)
1091{
1092        journal_t *journal = EXT4_SB(sb)->s_journal;
1093
1094        WARN_ON(PageChecked(page));
1095        if (!page_has_buffers(page))
1096                return 0;
1097        if (journal)
1098                return jbd2_journal_try_to_free_buffers(journal, page,
1099                                                        wait & ~__GFP_WAIT);
1100        return try_to_free_buffers(page);
1101}
1102
1103#ifdef CONFIG_QUOTA
1104#define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1105#define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1106
1107static int ext4_write_dquot(struct dquot *dquot);
1108static int ext4_acquire_dquot(struct dquot *dquot);
1109static int ext4_release_dquot(struct dquot *dquot);
1110static int ext4_mark_dquot_dirty(struct dquot *dquot);
1111static int ext4_write_info(struct super_block *sb, int type);
1112static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1113                         struct path *path);
1114static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1115                                 int format_id);
1116static int ext4_quota_off(struct super_block *sb, int type);
1117static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1118static int ext4_quota_on_mount(struct super_block *sb, int type);
1119static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1120                               size_t len, loff_t off);
1121static ssize_t ext4_quota_write(struct super_block *sb, int type,
1122                                const char *data, size_t len, loff_t off);
1123static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1124                             unsigned int flags);
1125static int ext4_enable_quotas(struct super_block *sb);
1126
1127static const struct dquot_operations ext4_quota_operations = {
1128        .get_reserved_space = ext4_get_reserved_space,
1129        .write_dquot    = ext4_write_dquot,
1130        .acquire_dquot  = ext4_acquire_dquot,
1131        .release_dquot  = ext4_release_dquot,
1132        .mark_dirty     = ext4_mark_dquot_dirty,
1133        .write_info     = ext4_write_info,
1134        .alloc_dquot    = dquot_alloc,
1135        .destroy_dquot  = dquot_destroy,
1136};
1137
1138static const struct quotactl_ops ext4_qctl_operations = {
1139        .quota_on       = ext4_quota_on,
1140        .quota_off      = ext4_quota_off,
1141        .quota_sync     = dquot_quota_sync,
1142        .get_info       = dquot_get_dqinfo,
1143        .set_info       = dquot_set_dqinfo,
1144        .get_dqblk      = dquot_get_dqblk,
1145        .set_dqblk      = dquot_set_dqblk
1146};
1147
1148static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1149        .quota_on_meta  = ext4_quota_on_sysfile,
1150        .quota_off      = ext4_quota_off_sysfile,
1151        .quota_sync     = dquot_quota_sync,
1152        .get_info       = dquot_get_dqinfo,
1153        .set_info       = dquot_set_dqinfo,
1154        .get_dqblk      = dquot_get_dqblk,
1155        .set_dqblk      = dquot_set_dqblk
1156};
1157#endif
1158
1159static const struct super_operations ext4_sops = {
1160        .alloc_inode    = ext4_alloc_inode,
1161        .destroy_inode  = ext4_destroy_inode,
1162        .write_inode    = ext4_write_inode,
1163        .dirty_inode    = ext4_dirty_inode,
1164        .drop_inode     = ext4_drop_inode,
1165        .evict_inode    = ext4_evict_inode,
1166        .put_super      = ext4_put_super,
1167        .sync_fs        = ext4_sync_fs,
1168        .freeze_fs      = ext4_freeze,
1169        .unfreeze_fs    = ext4_unfreeze,
1170        .statfs         = ext4_statfs,
1171        .remount_fs     = ext4_remount,
1172        .show_options   = ext4_show_options,
1173#ifdef CONFIG_QUOTA
1174        .quota_read     = ext4_quota_read,
1175        .quota_write    = ext4_quota_write,
1176#endif
1177        .bdev_try_to_free_page = bdev_try_to_free_page,
1178};
1179
1180static const struct super_operations ext4_nojournal_sops = {
1181        .alloc_inode    = ext4_alloc_inode,
1182        .destroy_inode  = ext4_destroy_inode,
1183        .write_inode    = ext4_write_inode,
1184        .dirty_inode    = ext4_dirty_inode,
1185        .drop_inode     = ext4_drop_inode,
1186        .evict_inode    = ext4_evict_inode,
1187        .put_super      = ext4_put_super,
1188        .statfs         = ext4_statfs,
1189        .remount_fs     = ext4_remount,
1190        .show_options   = ext4_show_options,
1191#ifdef CONFIG_QUOTA
1192        .quota_read     = ext4_quota_read,
1193        .quota_write    = ext4_quota_write,
1194#endif
1195        .bdev_try_to_free_page = bdev_try_to_free_page,
1196};
1197
1198static const struct export_operations ext4_export_ops = {
1199        .fh_to_dentry = ext4_fh_to_dentry,
1200        .fh_to_parent = ext4_fh_to_parent,
1201        .get_parent = ext4_get_parent,
1202};
1203
1204enum {
1205        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1206        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1207        Opt_nouid32, Opt_debug, Opt_removed,
1208        Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1209        Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1210        Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1211        Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1212        Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1213        Opt_data_err_abort, Opt_data_err_ignore,
1214        Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1215        Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1216        Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1217        Opt_usrquota, Opt_grpquota, Opt_i_version,
1218        Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1219        Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1220        Opt_inode_readahead_blks, Opt_journal_ioprio,
1221        Opt_dioread_nolock, Opt_dioread_lock,
1222        Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1223};
1224
1225static const match_table_t tokens = {
1226        {Opt_bsd_df, "bsddf"},
1227        {Opt_minix_df, "minixdf"},
1228        {Opt_grpid, "grpid"},
1229        {Opt_grpid, "bsdgroups"},
1230        {Opt_nogrpid, "nogrpid"},
1231        {Opt_nogrpid, "sysvgroups"},
1232        {Opt_resgid, "resgid=%u"},
1233        {Opt_resuid, "resuid=%u"},
1234        {Opt_sb, "sb=%u"},
1235        {Opt_err_cont, "errors=continue"},
1236        {Opt_err_panic, "errors=panic"},
1237        {Opt_err_ro, "errors=remount-ro"},
1238        {Opt_nouid32, "nouid32"},
1239        {Opt_debug, "debug"},
1240        {Opt_removed, "oldalloc"},
1241        {Opt_removed, "orlov"},
1242        {Opt_user_xattr, "user_xattr"},
1243        {Opt_nouser_xattr, "nouser_xattr"},
1244        {Opt_acl, "acl"},
1245        {Opt_noacl, "noacl"},
1246        {Opt_noload, "norecovery"},
1247        {Opt_noload, "noload"},
1248        {Opt_removed, "nobh"},
1249        {Opt_removed, "bh"},
1250        {Opt_commit, "commit=%u"},
1251        {Opt_min_batch_time, "min_batch_time=%u"},
1252        {Opt_max_batch_time, "max_batch_time=%u"},
1253        {Opt_journal_dev, "journal_dev=%u"},
1254        {Opt_journal_checksum, "journal_checksum"},
1255        {Opt_journal_async_commit, "journal_async_commit"},
1256        {Opt_abort, "abort"},
1257        {Opt_data_journal, "data=journal"},
1258        {Opt_data_ordered, "data=ordered"},
1259        {Opt_data_writeback, "data=writeback"},
1260        {Opt_data_err_abort, "data_err=abort"},
1261        {Opt_data_err_ignore, "data_err=ignore"},
1262        {Opt_offusrjquota, "usrjquota="},
1263        {Opt_usrjquota, "usrjquota=%s"},
1264        {Opt_offgrpjquota, "grpjquota="},
1265        {Opt_grpjquota, "grpjquota=%s"},
1266        {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1267        {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1268        {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1269        {Opt_grpquota, "grpquota"},
1270        {Opt_noquota, "noquota"},
1271        {Opt_quota, "quota"},
1272        {Opt_usrquota, "usrquota"},
1273        {Opt_barrier, "barrier=%u"},
1274        {Opt_barrier, "barrier"},
1275        {Opt_nobarrier, "nobarrier"},
1276        {Opt_i_version, "i_version"},
1277        {Opt_stripe, "stripe=%u"},
1278        {Opt_delalloc, "delalloc"},
1279        {Opt_nodelalloc, "nodelalloc"},
1280        {Opt_mblk_io_submit, "mblk_io_submit"},
1281        {Opt_nomblk_io_submit, "nomblk_io_submit"},
1282        {Opt_block_validity, "block_validity"},
1283        {Opt_noblock_validity, "noblock_validity"},
1284        {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1285        {Opt_journal_ioprio, "journal_ioprio=%u"},
1286        {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1287        {Opt_auto_da_alloc, "auto_da_alloc"},
1288        {Opt_noauto_da_alloc, "noauto_da_alloc"},
1289        {Opt_dioread_nolock, "dioread_nolock"},
1290        {Opt_dioread_lock, "dioread_lock"},
1291        {Opt_discard, "discard"},
1292        {Opt_nodiscard, "nodiscard"},
1293        {Opt_init_itable, "init_itable=%u"},
1294        {Opt_init_itable, "init_itable"},
1295        {Opt_noinit_itable, "noinit_itable"},
1296        {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1297        {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1298        {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1299        {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1300        {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1301        {Opt_err, NULL},
1302};
1303
1304static ext4_fsblk_t get_sb_block(void **data)
1305{
1306        ext4_fsblk_t    sb_block;
1307        char            *options = (char *) *data;
1308
1309        if (!options || strncmp(options, "sb=", 3) != 0)
1310                return 1;       /* Default location */
1311
1312        options += 3;
1313        /* TODO: use simple_strtoll with >32bit ext4 */
1314        sb_block = simple_strtoul(options, &options, 0);
1315        if (*options && *options != ',') {
1316                printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1317                       (char *) *data);
1318                return 1;
1319        }
1320        if (*options == ',')
1321                options++;
1322        *data = (void *) options;
1323
1324        return sb_block;
1325}
1326
1327#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1328static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1329        "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1330
1331#ifdef CONFIG_QUOTA
1332static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1333{
1334        struct ext4_sb_info *sbi = EXT4_SB(sb);
1335        char *qname;
1336
1337        if (sb_any_quota_loaded(sb) &&
1338                !sbi->s_qf_names[qtype]) {
1339                ext4_msg(sb, KERN_ERR,
1340                        "Cannot change journaled "
1341                        "quota options when quota turned on");
1342                return -1;
1343        }
1344        qname = match_strdup(args);
1345        if (!qname) {
1346                ext4_msg(sb, KERN_ERR,
1347                        "Not enough memory for storing quotafile name");
1348                return -1;
1349        }
1350        if (sbi->s_qf_names[qtype] &&
1351                strcmp(sbi->s_qf_names[qtype], qname)) {
1352                ext4_msg(sb, KERN_ERR,
1353                        "%s quota file already specified", QTYPE2NAME(qtype));
1354                kfree(qname);
1355                return -1;
1356        }
1357        sbi->s_qf_names[qtype] = qname;
1358        if (strchr(sbi->s_qf_names[qtype], '/')) {
1359                ext4_msg(sb, KERN_ERR,
1360                        "quotafile must be on filesystem root");
1361                kfree(sbi->s_qf_names[qtype]);
1362                sbi->s_qf_names[qtype] = NULL;
1363                return -1;
1364        }
1365        set_opt(sb, QUOTA);
1366        return 1;
1367}
1368
1369static int clear_qf_name(struct super_block *sb, int qtype)
1370{
1371
1372        struct ext4_sb_info *sbi = EXT4_SB(sb);
1373
1374        if (sb_any_quota_loaded(sb) &&
1375                sbi->s_qf_names[qtype]) {
1376                ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1377                        " when quota turned on");
1378                return -1;
1379        }
1380        /*
1381         * The space will be released later when all options are confirmed
1382         * to be correct
1383         */
1384        sbi->s_qf_names[qtype] = NULL;
1385        return 1;
1386}
1387#endif
1388
1389#define MOPT_SET        0x0001
1390#define MOPT_CLEAR      0x0002
1391#define MOPT_NOSUPPORT  0x0004
1392#define MOPT_EXPLICIT   0x0008
1393#define MOPT_CLEAR_ERR  0x0010
1394#define MOPT_GTE0       0x0020
1395#ifdef CONFIG_QUOTA
1396#define MOPT_Q          0
1397#define MOPT_QFMT       0x0040
1398#else
1399#define MOPT_Q          MOPT_NOSUPPORT
1400#define MOPT_QFMT       MOPT_NOSUPPORT
1401#endif
1402#define MOPT_DATAJ      0x0080
1403
1404static const struct mount_opts {
1405        int     token;
1406        int     mount_opt;
1407        int     flags;
1408} ext4_mount_opts[] = {
1409        {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1410        {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1411        {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1412        {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1413        {Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1414        {Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1415        {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1416        {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1417        {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1418        {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1419        {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1420        {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1421        {Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1422        {Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1423        {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1424        {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1425                                    EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1426        {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1427        {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1428        {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1429        {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1430        {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1431        {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1432        {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1433        {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1434        {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1435        {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1436        {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1437        {Opt_commit, 0, MOPT_GTE0},
1438        {Opt_max_batch_time, 0, MOPT_GTE0},
1439        {Opt_min_batch_time, 0, MOPT_GTE0},
1440        {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1441        {Opt_init_itable, 0, MOPT_GTE0},
1442        {Opt_stripe, 0, MOPT_GTE0},
1443        {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1444        {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1445        {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1446#ifdef CONFIG_EXT4_FS_XATTR
1447        {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1448        {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1449#else
1450        {Opt_user_xattr, 0, MOPT_NOSUPPORT},
1451        {Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
1452#endif
1453#ifdef CONFIG_EXT4_FS_POSIX_ACL
1454        {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1455        {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1456#else
1457        {Opt_acl, 0, MOPT_NOSUPPORT},
1458        {Opt_noacl, 0, MOPT_NOSUPPORT},
1459#endif
1460        {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1461        {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1462        {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1463        {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1464                                                        MOPT_SET | MOPT_Q},
1465        {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1466                                                        MOPT_SET | MOPT_Q},
1467        {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1468                       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1469        {Opt_usrjquota, 0, MOPT_Q},
1470        {Opt_grpjquota, 0, MOPT_Q},
1471        {Opt_offusrjquota, 0, MOPT_Q},
1472        {Opt_offgrpjquota, 0, MOPT_Q},
1473        {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1474        {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1475        {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1476        {Opt_err, 0, 0}
1477};
1478
1479static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1480                            substring_t *args, unsigned long *journal_devnum,
1481                            unsigned int *journal_ioprio, int is_remount)
1482{
1483        struct ext4_sb_info *sbi = EXT4_SB(sb);
1484        const struct mount_opts *m;
1485        kuid_t uid;
1486        kgid_t gid;
1487        int arg = 0;
1488
1489#ifdef CONFIG_QUOTA
1490        if (token == Opt_usrjquota)
1491                return set_qf_name(sb, USRQUOTA, &args[0]);
1492        else if (token == Opt_grpjquota)
1493                return set_qf_name(sb, GRPQUOTA, &args[0]);
1494        else if (token == Opt_offusrjquota)
1495                return clear_qf_name(sb, USRQUOTA);
1496        else if (token == Opt_offgrpjquota)
1497                return clear_qf_name(sb, GRPQUOTA);
1498#endif
1499        if (args->from && match_int(args, &arg))
1500                return -1;
1501        switch (token) {
1502        case Opt_noacl:
1503        case Opt_nouser_xattr:
1504                ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1505                break;
1506        case Opt_sb:
1507                return 1;       /* handled by get_sb_block() */
1508        case Opt_removed:
1509                ext4_msg(sb, KERN_WARNING,
1510                         "Ignoring removed %s option", opt);
1511                return 1;
1512        case Opt_resuid:
1513                uid = make_kuid(current_user_ns(), arg);
1514                if (!uid_valid(uid)) {
1515                        ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1516                        return -1;
1517                }
1518                sbi->s_resuid = uid;
1519                return 1;
1520        case Opt_resgid:
1521                gid = make_kgid(current_user_ns(), arg);
1522                if (!gid_valid(gid)) {
1523                        ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1524                        return -1;
1525                }
1526                sbi->s_resgid = gid;
1527                return 1;
1528        case Opt_abort:
1529                sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1530                return 1;
1531        case Opt_i_version:
1532                sb->s_flags |= MS_I_VERSION;
1533                return 1;
1534        case Opt_journal_dev:
1535                if (is_remount) {
1536                        ext4_msg(sb, KERN_ERR,
1537                                 "Cannot specify journal on remount");
1538                        return -1;
1539                }
1540                *journal_devnum = arg;
1541                return 1;
1542        case Opt_journal_ioprio:
1543                if (arg < 0 || arg > 7)
1544                        return -1;
1545                *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1546                return 1;
1547        }
1548
1549        for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1550                if (token != m->token)
1551                        continue;
1552                if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1553                        return -1;
1554                if (m->flags & MOPT_EXPLICIT)
1555                        set_opt2(sb, EXPLICIT_DELALLOC);
1556                if (m->flags & MOPT_CLEAR_ERR)
1557                        clear_opt(sb, ERRORS_MASK);
1558                if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1559                        ext4_msg(sb, KERN_ERR, "Cannot change quota "
1560                                 "options when quota turned on");
1561                        return -1;
1562                }
1563
1564                if (m->flags & MOPT_NOSUPPORT) {
1565                        ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1566                } else if (token == Opt_commit) {
1567                        if (arg == 0)
1568                                arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1569                        sbi->s_commit_interval = HZ * arg;
1570                } else if (token == Opt_max_batch_time) {
1571                        if (arg == 0)
1572                                arg = EXT4_DEF_MAX_BATCH_TIME;
1573                        sbi->s_max_batch_time = arg;
1574                } else if (token == Opt_min_batch_time) {
1575                        sbi->s_min_batch_time = arg;
1576                } else if (token == Opt_inode_readahead_blks) {
1577                        if (arg > (1 << 30))
1578                                return -1;
1579                        if (arg && !is_power_of_2(arg)) {
1580                                ext4_msg(sb, KERN_ERR,
1581                                         "EXT4-fs: inode_readahead_blks"
1582                                         " must be a power of 2");
1583                                return -1;
1584                        }
1585                        sbi->s_inode_readahead_blks = arg;
1586                } else if (token == Opt_init_itable) {
1587                        set_opt(sb, INIT_INODE_TABLE);
1588                        if (!args->from)
1589                                arg = EXT4_DEF_LI_WAIT_MULT;
1590                        sbi->s_li_wait_mult = arg;
1591                } else if (token == Opt_stripe) {
1592                        sbi->s_stripe = arg;
1593                } else if (m->flags & MOPT_DATAJ) {
1594                        if (is_remount) {
1595                                if (!sbi->s_journal)
1596                                        ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1597                                else if (test_opt(sb, DATA_FLAGS) !=
1598                                         m->mount_opt) {
1599                                        ext4_msg(sb, KERN_ERR,
1600                                         "Cannot change data mode on remount");
1601                                        return -1;
1602                                }
1603                        } else {
1604                                clear_opt(sb, DATA_FLAGS);
1605                                sbi->s_mount_opt |= m->mount_opt;
1606                        }
1607#ifdef CONFIG_QUOTA
1608                } else if (m->flags & MOPT_QFMT) {
1609                        if (sb_any_quota_loaded(sb) &&
1610                            sbi->s_jquota_fmt != m->mount_opt) {
1611                                ext4_msg(sb, KERN_ERR, "Cannot "
1612                                         "change journaled quota options "
1613                                         "when quota turned on");
1614                                return -1;
1615                        }
1616                        sbi->s_jquota_fmt = m->mount_opt;
1617#endif
1618                } else {
1619                        if (!args->from)
1620                                arg = 1;
1621                        if (m->flags & MOPT_CLEAR)
1622                                arg = !arg;
1623                        else if (unlikely(!(m->flags & MOPT_SET))) {
1624                                ext4_msg(sb, KERN_WARNING,
1625                                         "buggy handling of option %s", opt);
1626                                WARN_ON(1);
1627                                return -1;
1628                        }
1629                        if (arg != 0)
1630                                sbi->s_mount_opt |= m->mount_opt;
1631                        else
1632                                sbi->s_mount_opt &= ~m->mount_opt;
1633                }
1634                return 1;
1635        }
1636        ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1637                 "or missing value", opt);
1638        return -1;
1639}
1640
1641static int parse_options(char *options, struct super_block *sb,
1642                         unsigned long *journal_devnum,
1643                         unsigned int *journal_ioprio,
1644                         int is_remount)
1645{
1646#ifdef CONFIG_QUOTA
1647        struct ext4_sb_info *sbi = EXT4_SB(sb);
1648#endif
1649        char *p;
1650        substring_t args[MAX_OPT_ARGS];
1651        int token;
1652
1653        if (!options)
1654                return 1;
1655
1656        while ((p = strsep(&options, ",")) != NULL) {
1657                if (!*p)
1658                        continue;
1659                /*
1660                 * Initialize args struct so we know whether arg was
1661                 * found; some options take optional arguments.
1662                 */
1663                args[0].to = args[0].from = 0;
1664                token = match_token(p, tokens, args);
1665                if (handle_mount_opt(sb, p, token, args, journal_devnum,
1666                                     journal_ioprio, is_remount) < 0)
1667                        return 0;
1668        }
1669#ifdef CONFIG_QUOTA
1670        if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1671                if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1672                        clear_opt(sb, USRQUOTA);
1673
1674                if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1675                        clear_opt(sb, GRPQUOTA);
1676
1677                if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1678                        ext4_msg(sb, KERN_ERR, "old and new quota "
1679                                        "format mixing");
1680                        return 0;
1681                }
1682
1683                if (!sbi->s_jquota_fmt) {
1684                        ext4_msg(sb, KERN_ERR, "journaled quota format "
1685                                        "not specified");
1686                        return 0;
1687                }
1688        } else {
1689                if (sbi->s_jquota_fmt) {
1690                        ext4_msg(sb, KERN_ERR, "journaled quota format "
1691                                        "specified with no journaling "
1692                                        "enabled");
1693                        return 0;
1694                }
1695        }
1696#endif
1697        return 1;
1698}
1699
1700static inline void ext4_show_quota_options(struct seq_file *seq,
1701                                           struct super_block *sb)
1702{
1703#if defined(CONFIG_QUOTA)
1704        struct ext4_sb_info *sbi = EXT4_SB(sb);
1705
1706        if (sbi->s_jquota_fmt) {
1707                char *fmtname = "";
1708
1709                switch (sbi->s_jquota_fmt) {
1710                case QFMT_VFS_OLD:
1711                        fmtname = "vfsold";
1712                        break;
1713                case QFMT_VFS_V0:
1714                        fmtname = "vfsv0";
1715                        break;
1716                case QFMT_VFS_V1:
1717                        fmtname = "vfsv1";
1718                        break;
1719                }
1720                seq_printf(seq, ",jqfmt=%s", fmtname);
1721        }
1722
1723        if (sbi->s_qf_names[USRQUOTA])
1724                seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1725
1726        if (sbi->s_qf_names[GRPQUOTA])
1727                seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1728
1729        if (test_opt(sb, USRQUOTA))
1730                seq_puts(seq, ",usrquota");
1731
1732        if (test_opt(sb, GRPQUOTA))
1733                seq_puts(seq, ",grpquota");
1734#endif
1735}
1736
1737static const char *token2str(int token)
1738{
1739        const struct match_token *t;
1740
1741        for (t = tokens; t->token != Opt_err; t++)
1742                if (t->token == token && !strchr(t->pattern, '='))
1743                        break;
1744        return t->pattern;
1745}
1746
1747/*
1748 * Show an option if
1749 *  - it's set to a non-default value OR
1750 *  - if the per-sb default is different from the global default
1751 */
1752static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1753                              int nodefs)
1754{
1755        struct ext4_sb_info *sbi = EXT4_SB(sb);
1756        struct ext4_super_block *es = sbi->s_es;
1757        int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1758        const struct mount_opts *m;
1759        char sep = nodefs ? '\n' : ',';
1760
1761#define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1762#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1763
1764        if (sbi->s_sb_block != 1)
1765                SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1766
1767        for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1768                int want_set = m->flags & MOPT_SET;
1769                if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1770                    (m->flags & MOPT_CLEAR_ERR))
1771                        continue;
1772                if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1773                        continue; /* skip if same as the default */
1774                if ((want_set &&
1775                     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1776                    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1777                        continue; /* select Opt_noFoo vs Opt_Foo */
1778                SEQ_OPTS_PRINT("%s", token2str(m->token));
1779        }
1780
1781        if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1782            le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1783                SEQ_OPTS_PRINT("resuid=%u",
1784                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
1785        if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1786            le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1787                SEQ_OPTS_PRINT("resgid=%u",
1788                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
1789        def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1790        if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1791                SEQ_OPTS_PUTS("errors=remount-ro");
1792        if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1793                SEQ_OPTS_PUTS("errors=continue");
1794        if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1795                SEQ_OPTS_PUTS("errors=panic");
1796        if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1797                SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1798        if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1799                SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1800        if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1801                SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1802        if (sb->s_flags & MS_I_VERSION)
1803                SEQ_OPTS_PUTS("i_version");
1804        if (nodefs || sbi->s_stripe)
1805                SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1806        if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1807                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1808                        SEQ_OPTS_PUTS("data=journal");
1809                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1810                        SEQ_OPTS_PUTS("data=ordered");
1811                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1812                        SEQ_OPTS_PUTS("data=writeback");
1813        }
1814        if (nodefs ||
1815            sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1816                SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1817                               sbi->s_inode_readahead_blks);
1818
1819        if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1820                       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1821                SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1822
1823        ext4_show_quota_options(seq, sb);
1824        return 0;
1825}
1826
1827static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1828{
1829        return _ext4_show_options(seq, root->d_sb, 0);
1830}
1831
1832static int options_seq_show(struct seq_file *seq, void *offset)
1833{
1834        struct super_block *sb = seq->private;
1835        int rc;
1836
1837        seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1838        rc = _ext4_show_options(seq, sb, 1);
1839        seq_puts(seq, "\n");
1840        return rc;
1841}
1842
1843static int options_open_fs(struct inode *inode, struct file *file)
1844{
1845        return single_open(file, options_seq_show, PDE(inode)->data);
1846}
1847
1848static const struct file_operations ext4_seq_options_fops = {
1849        .owner = THIS_MODULE,
1850        .open = options_open_fs,
1851        .read = seq_read,
1852        .llseek = seq_lseek,
1853        .release = single_release,
1854};
1855
1856static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1857                            int read_only)
1858{
1859        struct ext4_sb_info *sbi = EXT4_SB(sb);
1860        int res = 0;
1861
1862        if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1863                ext4_msg(sb, KERN_ERR, "revision level too high, "
1864                         "forcing read-only mode");
1865                res = MS_RDONLY;
1866        }
1867        if (read_only)
1868                goto done;
1869        if (!(sbi->s_mount_state & EXT4_VALID_FS))
1870                ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1871                         "running e2fsck is recommended");
1872        else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1873                ext4_msg(sb, KERN_WARNING,
1874                         "warning: mounting fs with errors, "
1875                         "running e2fsck is recommended");
1876        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1877                 le16_to_cpu(es->s_mnt_count) >=
1878                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1879                ext4_msg(sb, KERN_WARNING,
1880                         "warning: maximal mount count reached, "
1881                         "running e2fsck is recommended");
1882        else if (le32_to_cpu(es->s_checkinterval) &&
1883                (le32_to_cpu(es->s_lastcheck) +
1884                        le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1885                ext4_msg(sb, KERN_WARNING,
1886                         "warning: checktime reached, "
1887                         "running e2fsck is recommended");
1888        if (!sbi->s_journal)
1889                es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1890        if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1891                es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1892        le16_add_cpu(&es->s_mnt_count, 1);
1893        es->s_mtime = cpu_to_le32(get_seconds());
1894        ext4_update_dynamic_rev(sb);
1895        if (sbi->s_journal)
1896                EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1897
1898        ext4_commit_super(sb, 1);
1899done:
1900        if (test_opt(sb, DEBUG))
1901                printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1902                                "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1903                        sb->s_blocksize,
1904                        sbi->s_groups_count,
1905                        EXT4_BLOCKS_PER_GROUP(sb),
1906                        EXT4_INODES_PER_GROUP(sb),
1907                        sbi->s_mount_opt, sbi->s_mount_opt2);
1908
1909        cleancache_init_fs(sb);
1910        return res;
1911}
1912
1913static int ext4_fill_flex_info(struct super_block *sb)
1914{
1915        struct ext4_sb_info *sbi = EXT4_SB(sb);
1916        struct ext4_group_desc *gdp = NULL;
1917        ext4_group_t flex_group_count;
1918        ext4_group_t flex_group;
1919        unsigned int groups_per_flex = 0;
1920        size_t size;
1921        int i;
1922
1923        sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1924        if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1925                sbi->s_log_groups_per_flex = 0;
1926                return 1;
1927        }
1928        groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1929
1930        /* We allocate both existing and potentially added groups */
1931        flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1932                        ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1933                              EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1934        size = flex_group_count * sizeof(struct flex_groups);
1935        sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
1936        if (sbi->s_flex_groups == NULL) {
1937                ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
1938                         flex_group_count);
1939                goto failed;
1940        }
1941
1942        for (i = 0; i < sbi->s_groups_count; i++) {
1943                gdp = ext4_get_group_desc(sb, i, NULL);
1944
1945                flex_group = ext4_flex_group(sbi, i);
1946                atomic_add(ext4_free_inodes_count(sb, gdp),
1947                           &sbi->s_flex_groups[flex_group].free_inodes);
1948                atomic_add(ext4_free_group_clusters(sb, gdp),
1949                           &sbi->s_flex_groups[flex_group].free_clusters);
1950                atomic_add(ext4_used_dirs_count(sb, gdp),
1951                           &sbi->s_flex_groups[flex_group].used_dirs);
1952        }
1953
1954        return 1;
1955failed:
1956        return 0;
1957}
1958
1959static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1960                                   struct ext4_group_desc *gdp)
1961{
1962        int offset;
1963        __u16 crc = 0;
1964        __le32 le_group = cpu_to_le32(block_group);
1965
1966        if ((sbi->s_es->s_feature_ro_compat &
1967             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1968                /* Use new metadata_csum algorithm */
1969                __u16 old_csum;
1970                __u32 csum32;
1971
1972                old_csum = gdp->bg_checksum;
1973                gdp->bg_checksum = 0;
1974                csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1975                                     sizeof(le_group));
1976                csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1977                                     sbi->s_desc_size);
1978                gdp->bg_checksum = old_csum;
1979
1980                crc = csum32 & 0xFFFF;
1981                goto out;
1982        }
1983
1984        /* old crc16 code */
1985        offset = offsetof(struct ext4_group_desc, bg_checksum);
1986
1987        crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1988        crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1989        crc = crc16(crc, (__u8 *)gdp, offset);
1990        offset += sizeof(gdp->bg_checksum); /* skip checksum */
1991        /* for checksum of struct ext4_group_desc do the rest...*/
1992        if ((sbi->s_es->s_feature_incompat &
1993             cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1994            offset < le16_to_cpu(sbi->s_es->s_desc_size))
1995                crc = crc16(crc, (__u8 *)gdp + offset,
1996                            le16_to_cpu(sbi->s_es->s_desc_size) -
1997                                offset);
1998
1999out:
2000        return cpu_to_le16(crc);
2001}
2002
2003int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2004                                struct ext4_group_desc *gdp)
2005{
2006        if (ext4_has_group_desc_csum(sb) &&
2007            (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2008                                                      block_group, gdp)))
2009                return 0;
2010
2011        return 1;
2012}
2013
2014void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2015                              struct ext4_group_desc *gdp)
2016{
2017        if (!ext4_has_group_desc_csum(sb))
2018                return;
2019        gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2020}
2021
2022/* Called at mount-time, super-block is locked */
2023static int ext4_check_descriptors(struct super_block *sb,
2024                                  ext4_group_t *first_not_zeroed)
2025{
2026        struct ext4_sb_info *sbi = EXT4_SB(sb);
2027        ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2028        ext4_fsblk_t last_block;
2029        ext4_fsblk_t block_bitmap;
2030        ext4_fsblk_t inode_bitmap;
2031        ext4_fsblk_t inode_table;
2032        int flexbg_flag = 0;
2033        ext4_group_t i, grp = sbi->s_groups_count;
2034
2035        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2036                flexbg_flag = 1;
2037
2038        ext4_debug("Checking group descriptors");
2039
2040        for (i = 0; i < sbi->s_groups_count; i++) {
2041                struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2042
2043                if (i == sbi->s_groups_count - 1 || flexbg_flag)
2044                        last_block = ext4_blocks_count(sbi->s_es) - 1;
2045                else
2046                        last_block = first_block +
2047                                (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2048
2049                if ((grp == sbi->s_groups_count) &&
2050                   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2051                        grp = i;
2052
2053                block_bitmap = ext4_block_bitmap(sb, gdp);
2054                if (block_bitmap < first_block || block_bitmap > last_block) {
2055                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2056                               "Block bitmap for group %u not in group "
2057                               "(block %llu)!", i, block_bitmap);
2058                        return 0;
2059                }
2060                inode_bitmap = ext4_inode_bitmap(sb, gdp);
2061                if (inode_bitmap < first_block || inode_bitmap > last_block) {
2062                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2063                               "Inode bitmap for group %u not in group "
2064                               "(block %llu)!", i, inode_bitmap);
2065                        return 0;
2066                }
2067                inode_table = ext4_inode_table(sb, gdp);
2068                if (inode_table < first_block ||
2069                    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2070                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2071                               "Inode table for group %u not in group "
2072                               "(block %llu)!", i, inode_table);
2073                        return 0;
2074                }
2075                ext4_lock_group(sb, i);
2076                if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2077                        ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2078                                 "Checksum for group %u failed (%u!=%u)",
2079                                 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2080                                     gdp)), le16_to_cpu(gdp->bg_checksum));
2081                        if (!(sb->s_flags & MS_RDONLY)) {
2082                                ext4_unlock_group(sb, i);
2083                                return 0;
2084                        }
2085                }
2086                ext4_unlock_group(sb, i);
2087                if (!flexbg_flag)
2088                        first_block += EXT4_BLOCKS_PER_GROUP(sb);
2089        }
2090        if (NULL != first_not_zeroed)
2091                *first_not_zeroed = grp;
2092
2093        ext4_free_blocks_count_set(sbi->s_es,
2094                                   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2095        sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2096        return 1;
2097}
2098
2099/* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2100 * the superblock) which were deleted from all directories, but held open by
2101 * a process at the time of a crash.  We walk the list and try to delete these
2102 * inodes at recovery time (only with a read-write filesystem).
2103 *
2104 * In order to keep the orphan inode chain consistent during traversal (in
2105 * case of crash during recovery), we link each inode into the superblock
2106 * orphan list_head and handle it the same way as an inode deletion during
2107 * normal operation (which journals the operations for us).
2108 *
2109 * We only do an iget() and an iput() on each inode, which is very safe if we
2110 * accidentally point at an in-use or already deleted inode.  The worst that
2111 * can happen in this case is that we get a "bit already cleared" message from
2112 * ext4_free_inode().  The only reason we would point at a wrong inode is if
2113 * e2fsck was run on this filesystem, and it must have already done the orphan
2114 * inode cleanup for us, so we can safely abort without any further action.
2115 */
2116static void ext4_orphan_cleanup(struct super_block *sb,
2117                                struct ext4_super_block *es)
2118{
2119        unsigned int s_flags = sb->s_flags;
2120        int nr_orphans = 0, nr_truncates = 0;
2121#ifdef CONFIG_QUOTA
2122        int i;
2123#endif
2124        if (!es->s_last_orphan) {
2125                jbd_debug(4, "no orphan inodes to clean up\n");
2126                return;
2127        }
2128
2129        if (bdev_read_only(sb->s_bdev)) {
2130                ext4_msg(sb, KERN_ERR, "write access "
2131                        "unavailable, skipping orphan cleanup");
2132                return;
2133        }
2134
2135        /* Check if feature set would not allow a r/w mount */
2136        if (!ext4_feature_set_ok(sb, 0)) {
2137                ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2138                         "unknown ROCOMPAT features");
2139                return;
2140        }
2141
2142        if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2143                if (es->s_last_orphan)
2144                        jbd_debug(1, "Errors on filesystem, "
2145                                  "clearing orphan list.\n");
2146                es->s_last_orphan = 0;
2147                jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2148                return;
2149        }
2150
2151        if (s_flags & MS_RDONLY) {
2152                ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2153                sb->s_flags &= ~MS_RDONLY;
2154        }
2155#ifdef CONFIG_QUOTA
2156        /* Needed for iput() to work correctly and not trash data */
2157        sb->s_flags |= MS_ACTIVE;
2158        /* Turn on quotas so that they are updated correctly */
2159        for (i = 0; i < MAXQUOTAS; i++) {
2160                if (EXT4_SB(sb)->s_qf_names[i]) {
2161                        int ret = ext4_quota_on_mount(sb, i);
2162                        if (ret < 0)
2163                                ext4_msg(sb, KERN_ERR,
2164                                        "Cannot turn on journaled "
2165                                        "quota: error %d", ret);
2166                }
2167        }
2168#endif
2169
2170        while (es->s_last_orphan) {
2171                struct inode *inode;
2172
2173                inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2174                if (IS_ERR(inode)) {
2175                        es->s_last_orphan = 0;
2176                        break;
2177                }
2178
2179                list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2180                dquot_initialize(inode);
2181                if (inode->i_nlink) {
2182                        ext4_msg(sb, KERN_DEBUG,
2183                                "%s: truncating inode %lu to %lld bytes",
2184                                __func__, inode->i_ino, inode->i_size);
2185                        jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2186                                  inode->i_ino, inode->i_size);
2187                        ext4_truncate(inode);
2188                        nr_truncates++;
2189                } else {
2190                        ext4_msg(sb, KERN_DEBUG,
2191                                "%s: deleting unreferenced inode %lu",
2192                                __func__, inode->i_ino);
2193                        jbd_debug(2, "deleting unreferenced inode %lu\n",
2194                                  inode->i_ino);
2195                        nr_orphans++;
2196                }
2197                iput(inode);  /* The delete magic happens here! */
2198        }
2199
2200#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2201
2202        if (nr_orphans)
2203                ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2204                       PLURAL(nr_orphans));
2205        if (nr_truncates)
2206                ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2207                       PLURAL(nr_truncates));
2208#ifdef CONFIG_QUOTA
2209        /* Turn quotas off */
2210        for (i = 0; i < MAXQUOTAS; i++) {
2211                if (sb_dqopt(sb)->files[i])
2212                        dquot_quota_off(sb, i);
2213        }
2214#endif
2215        sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2216}
2217
2218/*
2219 * Maximal extent format file size.
2220 * Resulting logical blkno at s_maxbytes must fit in our on-disk
2221 * extent format containers, within a sector_t, and within i_blocks
2222 * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2223 * so that won't be a limiting factor.
2224 *
2225 * However there is other limiting factor. We do store extents in the form
2226 * of starting block and length, hence the resulting length of the extent
2227 * covering maximum file size must fit into on-disk format containers as
2228 * well. Given that length is always by 1 unit bigger than max unit (because
2229 * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2230 *
2231 * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2232 */
2233static loff_t ext4_max_size(int blkbits, int has_huge_files)
2234{
2235        loff_t res;
2236        loff_t upper_limit = MAX_LFS_FILESIZE;
2237
2238        /* small i_blocks in vfs inode? */
2239        if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2240                /*
2241                 * CONFIG_LBDAF is not enabled implies the inode
2242                 * i_block represent total blocks in 512 bytes
2243                 * 32 == size of vfs inode i_blocks * 8
2244                 */
2245                upper_limit = (1LL << 32) - 1;
2246
2247                /* total blocks in file system block size */
2248                upper_limit >>= (blkbits - 9);
2249                upper_limit <<= blkbits;
2250        }
2251
2252        /*
2253         * 32-bit extent-start container, ee_block. We lower the maxbytes
2254         * by one fs block, so ee_len can cover the extent of maximum file
2255         * size
2256         */
2257        res = (1LL << 32) - 1;
2258        res <<= blkbits;
2259
2260        /* Sanity check against vm- & vfs- imposed limits */
2261        if (res > upper_limit)
2262                res = upper_limit;
2263
2264        return res;
2265}
2266
2267/*
2268 * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2269 * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2270 * We need to be 1 filesystem block less than the 2^48 sector limit.
2271 */
2272static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2273{
2274        loff_t res = EXT4_NDIR_BLOCKS;
2275        int meta_blocks;
2276        loff_t upper_limit;
2277        /* This is calculated to be the largest file size for a dense, block
2278         * mapped file such that the file's total number of 512-byte sectors,
2279         * including data and all indirect blocks, does not exceed (2^48 - 1).
2280         *
2281         * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2282         * number of 512-byte sectors of the file.
2283         */
2284
2285        if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2286                /*
2287                 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2288                 * the inode i_block field represents total file blocks in
2289                 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2290                 */
2291                upper_limit = (1LL << 32) - 1;
2292
2293                /* total blocks in file system block size */
2294                upper_limit >>= (bits - 9);
2295
2296        } else {
2297                /*
2298                 * We use 48 bit ext4_inode i_blocks
2299                 * With EXT4_HUGE_FILE_FL set the i_blocks
2300                 * represent total number of blocks in
2301                 * file system block size
2302                 */
2303                upper_limit = (1LL << 48) - 1;
2304
2305        }
2306
2307        /* indirect blocks */
2308        meta_blocks = 1;
2309        /* double indirect blocks */
2310        meta_blocks += 1 + (1LL << (bits-2));
2311        /* tripple indirect blocks */
2312        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2313
2314        upper_limit -= meta_blocks;
2315        upper_limit <<= bits;
2316
2317        res += 1LL << (bits-2);
2318        res += 1LL << (2*(bits-2));
2319        res += 1LL << (3*(bits-2));
2320        res <<= bits;
2321        if (res > upper_limit)
2322                res = upper_limit;
2323
2324        if (res > MAX_LFS_FILESIZE)
2325                res = MAX_LFS_FILESIZE;
2326
2327        return res;
2328}
2329
2330static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2331                                   ext4_fsblk_t logical_sb_block, int nr)
2332{
2333        struct ext4_sb_info *sbi = EXT4_SB(sb);
2334        ext4_group_t bg, first_meta_bg;
2335        int has_super = 0;
2336
2337        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2338
2339        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2340            nr < first_meta_bg)
2341                return logical_sb_block + nr + 1;
2342        bg = sbi->s_desc_per_block * nr;
2343        if (ext4_bg_has_super(sb, bg))
2344                has_super = 1;
2345
2346        return (has_super + ext4_group_first_block_no(sb, bg));
2347}
2348
2349/**
2350 * ext4_get_stripe_size: Get the stripe size.
2351 * @sbi: In memory super block info
2352 *
2353 * If we have specified it via mount option, then
2354 * use the mount option value. If the value specified at mount time is
2355 * greater than the blocks per group use the super block value.
2356 * If the super block value is greater than blocks per group return 0.
2357 * Allocator needs it be less than blocks per group.
2358 *
2359 */
2360static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2361{
2362        unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2363        unsigned long stripe_width =
2364                        le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2365        int ret;
2366
2367        if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2368                ret = sbi->s_stripe;
2369        else if (stripe_width <= sbi->s_blocks_per_group)
2370                ret = stripe_width;
2371        else if (stride <= sbi->s_blocks_per_group)
2372                ret = stride;
2373        else
2374                ret = 0;
2375
2376        /*
2377         * If the stripe width is 1, this makes no sense and
2378         * we set it to 0 to turn off stripe handling code.
2379         */
2380        if (ret <= 1)
2381                ret = 0;
2382
2383        return ret;
2384}
2385
2386/* sysfs supprt */
2387
2388struct ext4_attr {
2389        struct attribute attr;
2390        ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2391        ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2392                         const char *, size_t);
2393        int offset;
2394};
2395
2396static int parse_strtoul(const char *buf,
2397                unsigned long max, unsigned long *value)
2398{
2399        char *endp;
2400
2401        *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2402        endp = skip_spaces(endp);
2403        if (*endp || *value > max)
2404                return -EINVAL;
2405
2406        return 0;
2407}
2408
2409static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2410                                              struct ext4_sb_info *sbi,
2411                                              char *buf)
2412{
2413        return snprintf(buf, PAGE_SIZE, "%llu\n",
2414                (s64) EXT4_C2B(sbi,
2415                        percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2416}
2417
2418static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2419                                         struct ext4_sb_info *sbi, char *buf)
2420{
2421        struct super_block *sb = sbi->s_buddy_cache->i_sb;
2422
2423        if (!sb->s_bdev->bd_part)
2424                return snprintf(buf, PAGE_SIZE, "0\n");
2425        return snprintf(buf, PAGE_SIZE, "%lu\n",
2426                        (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2427                         sbi->s_sectors_written_start) >> 1);
2428}
2429
2430static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2431                                          struct ext4_sb_info *sbi, char *buf)
2432{
2433        struct super_block *sb = sbi->s_buddy_cache->i_sb;
2434
2435        if (!sb->s_bdev->bd_part)
2436                return snprintf(buf, PAGE_SIZE, "0\n");
2437        return snprintf(buf, PAGE_SIZE, "%llu\n",
2438                        (unsigned long long)(sbi->s_kbytes_written +
2439                        ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2440                          EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2441}
2442
2443static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2444                                          struct ext4_sb_info *sbi,
2445                                          const char *buf, size_t count)
2446{
2447        unsigned long t;
2448
2449        if (parse_strtoul(buf, 0x40000000, &t))
2450                return -EINVAL;
2451
2452        if (t && !is_power_of_2(t))
2453                return -EINVAL;
2454
2455        sbi->s_inode_readahead_blks = t;
2456        return count;
2457}
2458
2459static ssize_t sbi_ui_show(struct ext4_attr *a,
2460                           struct ext4_sb_info *sbi, char *buf)
2461{
2462        unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2463
2464        return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2465}
2466
2467static ssize_t sbi_ui_store(struct ext4_attr *a,
2468                            struct ext4_sb_info *sbi,
2469                            const char *buf, size_t count)
2470{
2471        unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2472        unsigned long t;
2473
2474        if (parse_strtoul(buf, 0xffffffff, &t))
2475                return -EINVAL;
2476        *ui = t;
2477        return count;
2478}
2479
2480static ssize_t trigger_test_error(struct ext4_attr *a,
2481                                  struct ext4_sb_info *sbi,
2482                                  const char *buf, size_t count)
2483{
2484        int len = count;
2485
2486        if (!capable(CAP_SYS_ADMIN))
2487                return -EPERM;
2488
2489        if (len && buf[len-1] == '\n')
2490                len--;
2491
2492        if (len)
2493                ext4_error(sbi->s_sb, "%.*s", len, buf);
2494        return count;
2495}
2496
2497#define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2498static struct ext4_attr ext4_attr_##_name = {                   \
2499        .attr = {.name = __stringify(_name), .mode = _mode },   \
2500        .show   = _show,                                        \
2501        .store  = _store,                                       \
2502        .offset = offsetof(struct ext4_sb_info, _elname),       \
2503}
2504#define EXT4_ATTR(name, mode, show, store) \
2505static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2506
2507#define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2508#define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2509#define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2510#define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2511        EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2512#define ATTR_LIST(name) &ext4_attr_##name.attr
2513
2514EXT4_RO_ATTR(delayed_allocation_blocks);
2515EXT4_RO_ATTR(session_write_kbytes);
2516EXT4_RO_ATTR(lifetime_write_kbytes);
2517EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2518                 inode_readahead_blks_store, s_inode_readahead_blks);
2519EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2520EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2521EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2522EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2523EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2524EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2525EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2526EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2527EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2528
2529static struct attribute *ext4_attrs[] = {
2530        ATTR_LIST(delayed_allocation_blocks),
2531        ATTR_LIST(session_write_kbytes),
2532        ATTR_LIST(lifetime_write_kbytes),
2533        ATTR_LIST(inode_readahead_blks),
2534        ATTR_LIST(inode_goal),
2535        ATTR_LIST(mb_stats),
2536        ATTR_LIST(mb_max_to_scan),
2537        ATTR_LIST(mb_min_to_scan),
2538        ATTR_LIST(mb_order2_req),
2539        ATTR_LIST(mb_stream_req),
2540        ATTR_LIST(mb_group_prealloc),
2541        ATTR_LIST(max_writeback_mb_bump),
2542        ATTR_LIST(trigger_fs_error),
2543        NULL,
2544};
2545
2546/* Features this copy of ext4 supports */
2547EXT4_INFO_ATTR(lazy_itable_init);
2548EXT4_INFO_ATTR(batched_discard);
2549
2550static struct attribute *ext4_feat_attrs[] = {
2551        ATTR_LIST(lazy_itable_init),
2552        ATTR_LIST(batched_discard),
2553        NULL,
2554};
2555
2556static ssize_t ext4_attr_show(struct kobject *kobj,
2557                              struct attribute *attr, char *buf)
2558{
2559        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2560                                                s_kobj);
2561        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2562
2563        return a->show ? a->show(a, sbi, buf) : 0;
2564}
2565
2566static ssize_t ext4_attr_store(struct kobject *kobj,
2567                               struct attribute *attr,
2568                               const char *buf, size_t len)
2569{
2570        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2571                                                s_kobj);
2572        struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2573
2574        return a->store ? a->store(a, sbi, buf, len) : 0;
2575}
2576
2577static void ext4_sb_release(struct kobject *kobj)
2578{
2579        struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2580                                                s_kobj);
2581        complete(&sbi->s_kobj_unregister);
2582}
2583
2584static const struct sysfs_ops ext4_attr_ops = {
2585        .show   = ext4_attr_show,
2586        .store  = ext4_attr_store,
2587};
2588
2589static struct kobj_type ext4_ktype = {
2590        .default_attrs  = ext4_attrs,
2591        .sysfs_ops      = &ext4_attr_ops,
2592        .release        = ext4_sb_release,
2593};
2594
2595static void ext4_feat_release(struct kobject *kobj)
2596{
2597        complete(&ext4_feat->f_kobj_unregister);
2598}
2599
2600static struct kobj_type ext4_feat_ktype = {
2601        .default_attrs  = ext4_feat_attrs,
2602        .sysfs_ops      = &ext4_attr_ops,
2603        .release        = ext4_feat_release,
2604};
2605
2606/*
2607 * Check whether this filesystem can be mounted based on
2608 * the features present and the RDONLY/RDWR mount requested.
2609 * Returns 1 if this filesystem can be mounted as requested,
2610 * 0 if it cannot be.
2611 */
2612static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2613{
2614        if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2615                ext4_msg(sb, KERN_ERR,
2616                        "Couldn't mount because of "
2617                        "unsupported optional features (%x)",
2618                        (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2619                        ~EXT4_FEATURE_INCOMPAT_SUPP));
2620                return 0;
2621        }
2622
2623        if (readonly)
2624                return 1;
2625
2626        /* Check that feature set is OK for a read-write mount */
2627        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2628                ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2629                         "unsupported optional features (%x)",
2630                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2631                                ~EXT4_FEATURE_RO_COMPAT_SUPP));
2632                return 0;
2633        }
2634        /*
2635         * Large file size enabled file system can only be mounted
2636         * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2637         */
2638        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2639                if (sizeof(blkcnt_t) < sizeof(u64)) {
2640                        ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2641                                 "cannot be mounted RDWR without "
2642                                 "CONFIG_LBDAF");
2643                        return 0;
2644                }
2645        }
2646        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2647            !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2648                ext4_msg(sb, KERN_ERR,
2649                         "Can't support bigalloc feature without "
2650                         "extents feature\n");
2651                return 0;
2652        }
2653
2654#ifndef CONFIG_QUOTA
2655        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2656            !readonly) {
2657                ext4_msg(sb, KERN_ERR,
2658                         "Filesystem with quota feature cannot be mounted RDWR "
2659                         "without CONFIG_QUOTA");
2660                return 0;
2661        }
2662#endif  /* CONFIG_QUOTA */
2663        return 1;
2664}
2665
2666/*
2667 * This function is called once a day if we have errors logged
2668 * on the file system
2669 */
2670static void print_daily_error_info(unsigned long arg)
2671{
2672        struct super_block *sb = (struct super_block *) arg;
2673        struct ext4_sb_info *sbi;
2674        struct ext4_super_block *es;
2675
2676        sbi = EXT4_SB(sb);
2677        es = sbi->s_es;
2678
2679        if (es->s_error_count)
2680                ext4_msg(sb, KERN_NOTICE, "error count: %u",
2681                         le32_to_cpu(es->s_error_count));
2682        if (es->s_first_error_time) {
2683                printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2684                       sb->s_id, le32_to_cpu(es->s_first_error_time),
2685                       (int) sizeof(es->s_first_error_func),
2686                       es->s_first_error_func,
2687                       le32_to_cpu(es->s_first_error_line));
2688                if (es->s_first_error_ino)
2689                        printk(": inode %u",
2690                               le32_to_cpu(es->s_first_error_ino));
2691                if (es->s_first_error_block)
2692                        printk(": block %llu", (unsigned long long)
2693                               le64_to_cpu(es->s_first_error_block));
2694                printk("\n");
2695        }
2696        if (es->s_last_error_time) {
2697                printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2698                       sb->s_id, le32_to_cpu(es->s_last_error_time),
2699                       (int) sizeof(es->s_last_error_func),
2700                       es->s_last_error_func,
2701                       le32_to_cpu(es->s_last_error_line));
2702                if (es->s_last_error_ino)
2703                        printk(": inode %u",
2704                               le32_to_cpu(es->s_last_error_ino));
2705                if (es->s_last_error_block)
2706                        printk(": block %llu", (unsigned long long)
2707                               le64_to_cpu(es->s_last_error_block));
2708                printk("\n");
2709        }
2710        mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2711}
2712
2713/* Find next suitable group and run ext4_init_inode_table */
2714static int ext4_run_li_request(struct ext4_li_request *elr)
2715{
2716        struct ext4_group_desc *gdp = NULL;
2717        ext4_group_t group, ngroups;
2718        struct super_block *sb;
2719        unsigned long timeout = 0;
2720        int ret = 0;
2721
2722        sb = elr->lr_super;
2723        ngroups = EXT4_SB(sb)->s_groups_count;
2724
2725        sb_start_write(sb);
2726        for (group = elr->lr_next_group; group < ngroups; group++) {
2727                gdp = ext4_get_group_desc(sb, group, NULL);
2728                if (!gdp) {
2729                        ret = 1;
2730                        break;
2731                }
2732
2733                if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2734                        break;
2735        }
2736
2737        if (group == ngroups)
2738                ret = 1;
2739
2740        if (!ret) {
2741                timeout = jiffies;
2742                ret = ext4_init_inode_table(sb, group,
2743                                            elr->lr_timeout ? 0 : 1);
2744                if (elr->lr_timeout == 0) {
2745                        timeout = (jiffies - timeout) *
2746                                  elr->lr_sbi->s_li_wait_mult;
2747                        elr->lr_timeout = timeout;
2748                }
2749                elr->lr_next_sched = jiffies + elr->lr_timeout;
2750                elr->lr_next_group = group + 1;
2751        }
2752        sb_end_write(sb);
2753
2754        return ret;
2755}
2756
2757/*
2758 * Remove lr_request from the list_request and free the
2759 * request structure. Should be called with li_list_mtx held
2760 */
2761static void ext4_remove_li_request(struct ext4_li_request *elr)
2762{
2763        struct ext4_sb_info *sbi;
2764
2765        if (!elr)
2766                return;
2767
2768        sbi = elr->lr_sbi;
2769
2770        list_del(&elr->lr_request);
2771        sbi->s_li_request = NULL;
2772        kfree(elr);
2773}
2774
2775static void ext4_unregister_li_request(struct super_block *sb)
2776{
2777        mutex_lock(&ext4_li_mtx);
2778        if (!ext4_li_info) {
2779                mutex_unlock(&ext4_li_mtx);
2780                return;
2781        }
2782
2783        mutex_lock(&ext4_li_info->li_list_mtx);
2784        ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2785        mutex_unlock(&ext4_li_info->li_list_mtx);
2786        mutex_unlock(&ext4_li_mtx);
2787}
2788
2789static struct task_struct *ext4_lazyinit_task;
2790
2791/*
2792 * This is the function where ext4lazyinit thread lives. It walks
2793 * through the request list searching for next scheduled filesystem.
2794 * When such a fs is found, run the lazy initialization request
2795 * (ext4_rn_li_request) and keep track of the time spend in this
2796 * function. Based on that time we compute next schedule time of
2797 * the request. When walking through the list is complete, compute
2798 * next waking time and put itself into sleep.
2799 */
2800static int ext4_lazyinit_thread(void *arg)
2801{
2802        struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2803        struct list_head *pos, *n;
2804        struct ext4_li_request *elr;
2805        unsigned long next_wakeup, cur;
2806
2807        BUG_ON(NULL == eli);
2808
2809cont_thread:
2810        while (true) {
2811                next_wakeup = MAX_JIFFY_OFFSET;
2812
2813                mutex_lock(&eli->li_list_mtx);
2814                if (list_empty(&eli->li_request_list)) {
2815                        mutex_unlock(&eli->li_list_mtx);
2816                        goto exit_thread;
2817                }
2818
2819                list_for_each_safe(pos, n, &eli->li_request_list) {
2820                        elr = list_entry(pos, struct ext4_li_request,
2821                                         lr_request);
2822
2823                        if (time_after_eq(jiffies, elr->lr_next_sched)) {
2824                                if (ext4_run_li_request(elr) != 0) {
2825                                        /* error, remove the lazy_init job */
2826                                        ext4_remove_li_request(elr);
2827                                        continue;
2828                                }
2829                        }
2830
2831                        if (time_before(elr->lr_next_sched, next_wakeup))
2832                                next_wakeup = elr->lr_next_sched;
2833                }
2834                mutex_unlock(&eli->li_list_mtx);
2835
2836                try_to_freeze();
2837
2838                cur = jiffies;
2839                if ((time_after_eq(cur, next_wakeup)) ||
2840                    (MAX_JIFFY_OFFSET == next_wakeup)) {
2841                        cond_resched();
2842                        continue;
2843                }
2844
2845                schedule_timeout_interruptible(next_wakeup - cur);
2846
2847                if (kthread_should_stop()) {
2848                        ext4_clear_request_list();
2849                        goto exit_thread;
2850                }
2851        }
2852
2853exit_thread:
2854        /*
2855         * It looks like the request list is empty, but we need
2856         * to check it under the li_list_mtx lock, to prevent any
2857         * additions into it, and of course we should lock ext4_li_mtx
2858         * to atomically free the list and ext4_li_info, because at
2859         * this point another ext4 filesystem could be registering
2860         * new one.
2861         */
2862        mutex_lock(&ext4_li_mtx);
2863        mutex_lock(&eli->li_list_mtx);
2864        if (!list_empty(&eli->li_request_list)) {
2865                mutex_unlock(&eli->li_list_mtx);
2866                mutex_unlock(&ext4_li_mtx);
2867                goto cont_thread;
2868        }
2869        mutex_unlock(&eli->li_list_mtx);
2870        kfree(ext4_li_info);
2871        ext4_li_info = NULL;
2872        mutex_unlock(&ext4_li_mtx);
2873
2874        return 0;
2875}
2876
2877static void ext4_clear_request_list(void)
2878{
2879        struct list_head *pos, *n;
2880        struct ext4_li_request *elr;
2881
2882        mutex_lock(&ext4_li_info->li_list_mtx);
2883        list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2884                elr = list_entry(pos, struct ext4_li_request,
2885                                 lr_request);
2886                ext4_remove_li_request(elr);
2887        }
2888        mutex_unlock(&ext4_li_info->li_list_mtx);
2889}
2890
2891static int ext4_run_lazyinit_thread(void)
2892{
2893        ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2894                                         ext4_li_info, "ext4lazyinit");
2895        if (IS_ERR(ext4_lazyinit_task)) {
2896                int err = PTR_ERR(ext4_lazyinit_task);
2897                ext4_clear_request_list();
2898                kfree(ext4_li_info);
2899                ext4_li_info = NULL;
2900                printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2901                                 "initialization thread\n",
2902                                 err);
2903                return err;
2904        }
2905        ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2906        return 0;
2907}
2908
2909/*
2910 * Check whether it make sense to run itable init. thread or not.
2911 * If there is at least one uninitialized inode table, return
2912 * corresponding group number, else the loop goes through all
2913 * groups and return total number of groups.
2914 */
2915static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2916{
2917        ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2918        struct ext4_group_desc *gdp = NULL;
2919
2920        for (group = 0; group < ngroups; group++) {
2921                gdp = ext4_get_group_desc(sb, group, NULL);
2922                if (!gdp)
2923                        continue;
2924
2925                if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2926                        break;
2927        }
2928
2929        return group;
2930}
2931
2932static int ext4_li_info_new(void)
2933{
2934        struct ext4_lazy_init *eli = NULL;
2935
2936        eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2937        if (!eli)
2938                return -ENOMEM;
2939
2940        INIT_LIST_HEAD(&eli->li_request_list);
2941        mutex_init(&eli->li_list_mtx);
2942
2943        eli->li_state |= EXT4_LAZYINIT_QUIT;
2944
2945        ext4_li_info = eli;
2946
2947        return 0;
2948}
2949
2950static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2951                                            ext4_group_t start)
2952{
2953        struct ext4_sb_info *sbi = EXT4_SB(sb);
2954        struct ext4_li_request *elr;
2955        unsigned long rnd;
2956
2957        elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2958        if (!elr)
2959                return NULL;
2960
2961        elr->lr_super = sb;
2962        elr->lr_sbi = sbi;
2963        elr->lr_next_group = start;
2964
2965        /*
2966         * Randomize first schedule time of the request to
2967         * spread the inode table initialization requests
2968         * better.
2969         */
2970        get_random_bytes(&rnd, sizeof(rnd));
2971        elr->lr_next_sched = jiffies + (unsigned long)rnd %
2972                             (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2973
2974        return elr;
2975}
2976
2977static int ext4_register_li_request(struct super_block *sb,
2978                                    ext4_group_t first_not_zeroed)
2979{
2980        struct ext4_sb_info *sbi = EXT4_SB(sb);
2981        struct ext4_li_request *elr;
2982        ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2983        int ret = 0;
2984
2985        if (sbi->s_li_request != NULL) {
2986                /*
2987                 * Reset timeout so it can be computed again, because
2988                 * s_li_wait_mult might have changed.
2989                 */
2990                sbi->s_li_request->lr_timeout = 0;
2991                return 0;
2992        }
2993
2994        if (first_not_zeroed == ngroups ||
2995            (sb->s_flags & MS_RDONLY) ||
2996            !test_opt(sb, INIT_INODE_TABLE))
2997                return 0;
2998
2999        elr = ext4_li_request_new(sb, first_not_zeroed);
3000        if (!elr)
3001                return -ENOMEM;
3002
3003        mutex_lock(&ext4_li_mtx);
3004
3005        if (NULL == ext4_li_info) {
3006                ret = ext4_li_info_new();
3007                if (ret)
3008                        goto out;
3009        }
3010
3011        mutex_lock(&ext4_li_info->li_list_mtx);
3012        list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3013        mutex_unlock(&ext4_li_info->li_list_mtx);
3014
3015        sbi->s_li_request = elr;
3016        /*
3017         * set elr to NULL here since it has been inserted to
3018         * the request_list and the removal and free of it is
3019         * handled by ext4_clear_request_list from now on.
3020         */
3021        elr = NULL;
3022
3023        if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3024                ret = ext4_run_lazyinit_thread();
3025                if (ret)
3026                        goto out;
3027        }
3028out:
3029        mutex_unlock(&ext4_li_mtx);
3030        if (ret)
3031                kfree(elr);
3032        return ret;
3033}
3034
3035/*
3036 * We do not need to lock anything since this is called on
3037 * module unload.
3038 */
3039static void ext4_destroy_lazyinit_thread(void)
3040{
3041        /*
3042         * If thread exited earlier
3043         * there's nothing to be done.
3044         */
3045        if (!ext4_li_info || !ext4_lazyinit_task)
3046                return;
3047
3048        kthread_stop(ext4_lazyinit_task);
3049}
3050
3051static int set_journal_csum_feature_set(struct super_block *sb)
3052{
3053        int ret = 1;
3054        int compat, incompat;
3055        struct ext4_sb_info *sbi = EXT4_SB(sb);
3056
3057        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3058                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3059                /* journal checksum v2 */
3060                compat = 0;
3061                incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3062        } else {
3063                /* journal checksum v1 */
3064                compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3065                incompat = 0;
3066        }
3067
3068        if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3069                ret = jbd2_journal_set_features(sbi->s_journal,
3070                                compat, 0,
3071                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3072                                incompat);
3073        } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3074                ret = jbd2_journal_set_features(sbi->s_journal,
3075                                compat, 0,
3076                                incompat);
3077                jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3078                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3079        } else {
3080                jbd2_journal_clear_features(sbi->s_journal,
3081                                JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3082                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3083                                JBD2_FEATURE_INCOMPAT_CSUM_V2);
3084        }
3085
3086        return ret;
3087}
3088
3089/*
3090 * Note: calculating the overhead so we can be compatible with
3091 * historical BSD practice is quite difficult in the face of
3092 * clusters/bigalloc.  This is because multiple metadata blocks from
3093 * different block group can end up in the same allocation cluster.
3094 * Calculating the exact overhead in the face of clustered allocation
3095 * requires either O(all block bitmaps) in memory or O(number of block
3096 * groups**2) in time.  We will still calculate the superblock for
3097 * older file systems --- and if we come across with a bigalloc file
3098 * system with zero in s_overhead_clusters the estimate will be close to
3099 * correct especially for very large cluster sizes --- but for newer
3100 * file systems, it's better to calculate this figure once at mkfs
3101 * time, and store it in the superblock.  If the superblock value is
3102 * present (even for non-bigalloc file systems), we will use it.
3103 */
3104static int count_overhead(struct super_block *sb, ext4_group_t grp,
3105                          char *buf)
3106{
3107        struct ext4_sb_info     *sbi = EXT4_SB(sb);
3108        struct ext4_group_desc  *gdp;
3109        ext4_fsblk_t            first_block, last_block, b;
3110        ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3111        int                     s, j, count = 0;
3112
3113        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3114                return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3115                        sbi->s_itb_per_group + 2);
3116
3117        first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3118                (grp * EXT4_BLOCKS_PER_GROUP(sb));
3119        last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3120        for (i = 0; i < ngroups; i++) {
3121                gdp = ext4_get_group_desc(sb, i, NULL);
3122                b = ext4_block_bitmap(sb, gdp);
3123                if (b >= first_block && b <= last_block) {
3124                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3125                        count++;
3126                }
3127                b = ext4_inode_bitmap(sb, gdp);
3128                if (b >= first_block && b <= last_block) {
3129                        ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3130                        count++;
3131                }
3132                b = ext4_inode_table(sb, gdp);
3133                if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3134                        for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3135                                int c = EXT4_B2C(sbi, b - first_block);
3136                                ext4_set_bit(c, buf);
3137                                count++;
3138                        }
3139                if (i != grp)
3140                        continue;
3141                s = 0;
3142                if (ext4_bg_has_super(sb, grp)) {
3143                        ext4_set_bit(s++, buf);
3144                        count++;
3145                }
3146                for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3147                        ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3148                        count++;
3149                }
3150        }
3151        if (!count)
3152                return 0;
3153        return EXT4_CLUSTERS_PER_GROUP(sb) -
3154                ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3155}
3156
3157/*
3158 * Compute the overhead and stash it in sbi->s_overhead
3159 */
3160int ext4_calculate_overhead(struct super_block *sb)
3161{
3162        struct ext4_sb_info *sbi = EXT4_SB(sb);
3163        struct ext4_super_block *es = sbi->s_es;
3164        ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3165        ext4_fsblk_t overhead = 0;
3166        char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3167
3168        memset(buf, 0, PAGE_SIZE);
3169        if (!buf)
3170                return -ENOMEM;
3171
3172        /*
3173         * Compute the overhead (FS structures).  This is constant
3174         * for a given filesystem unless the number of block groups
3175         * changes so we cache the previous value until it does.
3176         */
3177
3178        /*
3179         * All of the blocks before first_data_block are overhead
3180         */
3181        overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3182
3183        /*
3184         * Add the overhead found in each block group
3185         */
3186        for (i = 0; i < ngroups; i++) {
3187                int blks;
3188
3189                blks = count_overhead(sb, i, buf);
3190                overhead += blks;
3191                if (blks)
3192                        memset(buf, 0, PAGE_SIZE);
3193                cond_resched();
3194        }
3195        sbi->s_overhead = overhead;
3196        smp_wmb();
3197        free_page((unsigned long) buf);
3198        return 0;
3199}
3200
3201static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3202{
3203        char *orig_data = kstrdup(data, GFP_KERNEL);
3204        struct buffer_head *bh;
3205        struct ext4_super_block *es = NULL;
3206        struct ext4_sb_info *sbi;
3207        ext4_fsblk_t block;
3208        ext4_fsblk_t sb_block = get_sb_block(&data);
3209        ext4_fsblk_t logical_sb_block;
3210        unsigned long offset = 0;
3211        unsigned long journal_devnum = 0;
3212        unsigned long def_mount_opts;
3213        struct inode *root;
3214        char *cp;
3215        const char *descr;
3216        int ret = -ENOMEM;
3217        int blocksize, clustersize;
3218        unsigned int db_count;
3219        unsigned int i;
3220        int needs_recovery, has_huge_files, has_bigalloc;
3221        __u64 blocks_count;
3222        int err;
3223        unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3224        ext4_group_t first_not_zeroed;
3225
3226        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3227        if (!sbi)
3228                goto out_free_orig;
3229
3230        sbi->s_blockgroup_lock =
3231                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3232        if (!sbi->s_blockgroup_lock) {
3233                kfree(sbi);
3234                goto out_free_orig;
3235        }
3236        sb->s_fs_info = sbi;
3237        sbi->s_sb = sb;
3238        sbi->s_mount_opt = 0;
3239        sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
3240        sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
3241        sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3242        sbi->s_sb_block = sb_block;
3243        if (sb->s_bdev->bd_part)
3244                sbi->s_sectors_written_start =
3245                        part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3246
3247        /* Cleanup superblock name */
3248        for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3249                *cp = '!';
3250
3251        ret = -EINVAL;
3252        blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3253        if (!blocksize) {
3254                ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3255                goto out_fail;
3256        }
3257
3258        /*
3259         * The ext4 superblock will not be buffer aligned for other than 1kB
3260         * block sizes.  We need to calculate the offset from buffer start.
3261         */
3262        if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3263                logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3264                offset = do_div(logical_sb_block, blocksize);
3265        } else {
3266                logical_sb_block = sb_block;
3267        }
3268
3269        if (!(bh = sb_bread(sb, logical_sb_block))) {
3270                ext4_msg(sb, KERN_ERR, "unable to read superblock");
3271                goto out_fail;
3272        }
3273        /*
3274         * Note: s_es must be initialized as soon as possible because
3275         *       some ext4 macro-instructions depend on its value
3276         */
3277        es = (struct ext4_super_block *) (bh->b_data + offset);
3278        sbi->s_es = es;
3279        sb->s_magic = le16_to_cpu(es->s_magic);
3280        if (sb->s_magic != EXT4_SUPER_MAGIC)
3281                goto cantfind_ext4;
3282        sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3283
3284        /* Warn if metadata_csum and gdt_csum are both set. */
3285        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3286                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3287            EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3288                ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3289                             "redundant flags; please run fsck.");
3290
3291        /* Check for a known checksum algorithm */
3292        if (!ext4_verify_csum_type(sb, es)) {
3293                ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3294                         "unknown checksum algorithm.");
3295                silent = 1;
3296                goto cantfind_ext4;
3297        }
3298
3299        /* Load the checksum driver */
3300        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3301                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3302                sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3303                if (IS_ERR(sbi->s_chksum_driver)) {
3304                        ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3305                        ret = PTR_ERR(sbi->s_chksum_driver);
3306                        sbi->s_chksum_driver = NULL;
3307                        goto failed_mount;
3308                }
3309        }
3310
3311        /* Check superblock checksum */
3312        if (!ext4_superblock_csum_verify(sb, es)) {
3313                ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3314                         "invalid superblock checksum.  Run e2fsck?");
3315                silent = 1;
3316                goto cantfind_ext4;
3317        }
3318
3319        /* Precompute checksum seed for all metadata */
3320        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3321                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3322                sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3323                                               sizeof(es->s_uuid));
3324
3325        /* Set defaults before we parse the mount options */
3326        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3327        set_opt(sb, INIT_INODE_TABLE);
3328        if (def_mount_opts & EXT4_DEFM_DEBUG)
3329                set_opt(sb, DEBUG);
3330        if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3331                set_opt(sb, GRPID);
3332        if (def_mount_opts & EXT4_DEFM_UID16)
3333                set_opt(sb, NO_UID32);
3334        /* xattr user namespace & acls are now defaulted on */
3335#ifdef CONFIG_EXT4_FS_XATTR
3336        set_opt(sb, XATTR_USER);
3337#endif
3338#ifdef CONFIG_EXT4_FS_POSIX_ACL
3339        set_opt(sb, POSIX_ACL);
3340#endif
3341        set_opt(sb, MBLK_IO_SUBMIT);
3342        if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3343                set_opt(sb, JOURNAL_DATA);
3344        else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3345                set_opt(sb, ORDERED_DATA);
3346        else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3347                set_opt(sb, WRITEBACK_DATA);
3348
3349        if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3350                set_opt(sb, ERRORS_PANIC);
3351        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3352                set_opt(sb, ERRORS_CONT);
3353        else
3354                set_opt(sb, ERRORS_RO);
3355        if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3356                set_opt(sb, BLOCK_VALIDITY);
3357        if (def_mount_opts & EXT4_DEFM_DISCARD)
3358                set_opt(sb, DISCARD);
3359
3360        sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3361        sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3362        sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3363        sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3364        sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3365
3366        if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3367                set_opt(sb, BARRIER);
3368
3369        /*
3370         * enable delayed allocation by default
3371         * Use -o nodelalloc to turn it off
3372         */
3373        if (!IS_EXT3_SB(sb) &&
3374            ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3375                set_opt(sb, DELALLOC);
3376
3377        /*
3378         * set default s_li_wait_mult for lazyinit, for the case there is
3379         * no mount option specified.
3380         */
3381        sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3382
3383        if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3384                           &journal_devnum, &journal_ioprio, 0)) {
3385                ext4_msg(sb, KERN_WARNING,
3386                         "failed to parse options in superblock: %s",
3387                         sbi->s_es->s_mount_opts);
3388        }
3389        sbi->s_def_mount_opt = sbi->s_mount_opt;
3390        if (!parse_options((char *) data, sb, &journal_devnum,
3391                           &journal_ioprio, 0))
3392                goto failed_mount;
3393
3394        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3395                printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3396                            "with data=journal disables delayed "
3397                            "allocation and O_DIRECT support!\n");
3398                if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3399                        ext4_msg(sb, KERN_ERR, "can't mount with "
3400                                 "both data=journal and delalloc");
3401                        goto failed_mount;
3402                }
3403                if (test_opt(sb, DIOREAD_NOLOCK)) {
3404                        ext4_msg(sb, KERN_ERR, "can't mount with "
3405                                 "both data=journal and delalloc");
3406                        goto failed_mount;
3407                }
3408                if (test_opt(sb, DELALLOC))
3409                        clear_opt(sb, DELALLOC);
3410        }
3411
3412        blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3413        if (test_opt(sb, DIOREAD_NOLOCK)) {
3414                if (blocksize < PAGE_SIZE) {
3415                        ext4_msg(sb, KERN_ERR, "can't mount with "
3416                                 "dioread_nolock if block size != PAGE_SIZE");
3417                        goto failed_mount;
3418                }
3419        }
3420
3421        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3422                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3423
3424        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3425            (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3426             EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3427             EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3428                ext4_msg(sb, KERN_WARNING,
3429                       "feature flags set on rev 0 fs, "
3430                       "running e2fsck is recommended");
3431
3432        if (IS_EXT2_SB(sb)) {
3433                if (ext2_feature_set_ok(sb))
3434                        ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3435                                 "using the ext4 subsystem");
3436                else {
3437                        ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3438                                 "to feature incompatibilities");
3439                        goto failed_mount;
3440                }
3441        }
3442
3443        if (IS_EXT3_SB(sb)) {
3444                if (ext3_feature_set_ok(sb))
3445                        ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3446                                 "using the ext4 subsystem");
3447                else {
3448                        ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3449                                 "to feature incompatibilities");
3450                        goto failed_mount;
3451                }
3452        }
3453
3454        /*
3455         * Check feature flags regardless of the revision level, since we
3456         * previously didn't change the revision level when setting the flags,
3457         * so there is a chance incompat flags are set on a rev 0 filesystem.
3458         */
3459        if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3460                goto failed_mount;
3461
3462        if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3463            blocksize > EXT4_MAX_BLOCK_SIZE) {
3464                ext4_msg(sb, KERN_ERR,
3465                       "Unsupported filesystem blocksize %d", blocksize);
3466                goto failed_mount;
3467        }
3468
3469        if (sb->s_blocksize != blocksize) {
3470                /* Validate the filesystem blocksize */
3471                if (!sb_set_blocksize(sb, blocksize)) {
3472                        ext4_msg(sb, KERN_ERR, "bad block size %d",
3473                                        blocksize);
3474                        goto failed_mount;
3475                }
3476
3477                brelse(bh);
3478                logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3479                offset = do_div(logical_sb_block, blocksize);
3480                bh = sb_bread(sb, logical_sb_block);
3481                if (!bh) {
3482                        ext4_msg(sb, KERN_ERR,
3483                               "Can't read superblock on 2nd try");
3484                        goto failed_mount;
3485                }
3486                es = (struct ext4_super_block *)(bh->b_data + offset);
3487                sbi->s_es = es;
3488                if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3489                        ext4_msg(sb, KERN_ERR,
3490                               "Magic mismatch, very weird!");
3491                        goto failed_mount;
3492                }
3493        }
3494
3495        has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3496                                EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3497        sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3498                                                      has_huge_files);
3499        sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3500
3501        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3502                sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3503                sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3504        } else {
3505                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3506                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3507                if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3508                    (!is_power_of_2(sbi->s_inode_size)) ||
3509                    (sbi->s_inode_size > blocksize)) {
3510                        ext4_msg(sb, KERN_ERR,
3511                               "unsupported inode size: %d",
3512                               sbi->s_inode_size);
3513                        goto failed_mount;
3514                }
3515                if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3516                        sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3517        }
3518
3519        sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3520        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3521                if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3522                    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3523                    !is_power_of_2(sbi->s_desc_size)) {
3524                        ext4_msg(sb, KERN_ERR,
3525                               "unsupported descriptor size %lu",
3526                               sbi->s_desc_size);
3527                        goto failed_mount;
3528                }
3529        } else
3530                sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3531
3532        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3533        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3534        if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3535                goto cantfind_ext4;
3536
3537        sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3538        if (sbi->s_inodes_per_block == 0)
3539                goto cantfind_ext4;
3540        sbi->s_itb_per_group = sbi->s_inodes_per_group /
3541                                        sbi->s_inodes_per_block;
3542        sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3543        sbi->s_sbh = bh;
3544        sbi->s_mount_state = le16_to_cpu(es->s_state);
3545        sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3546        sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3547
3548        for (i = 0; i < 4; i++)
3549                sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3550        sbi->s_def_hash_version = es->s_def_hash_version;
3551        i = le32_to_cpu(es->s_flags);
3552        if (i & EXT2_FLAGS_UNSIGNED_HASH)
3553                sbi->s_hash_unsigned = 3;
3554        else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3555#ifdef __CHAR_UNSIGNED__
3556                es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3557                sbi->s_hash_unsigned = 3;
3558#else
3559                es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3560#endif
3561        }
3562
3563        /* Handle clustersize */
3564        clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3565        has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3566                                EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3567        if (has_bigalloc) {
3568                if (clustersize < blocksize) {
3569                        ext4_msg(sb, KERN_ERR,
3570                                 "cluster size (%d) smaller than "
3571                                 "block size (%d)", clustersize, blocksize);
3572                        goto failed_mount;
3573                }
3574                sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3575                        le32_to_cpu(es->s_log_block_size);
3576                sbi->s_clusters_per_group =
3577                        le32_to_cpu(es->s_clusters_per_group);
3578                if (sbi->s_clusters_per_group > blocksize * 8) {
3579                        ext4_msg(sb, KERN_ERR,
3580                                 "#clusters per group too big: %lu",
3581                                 sbi->s_clusters_per_group);
3582                        goto failed_mount;
3583                }
3584                if (sbi->s_blocks_per_group !=
3585                    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3586                        ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3587                                 "clusters per group (%lu) inconsistent",
3588                                 sbi->s_blocks_per_group,
3589                                 sbi->s_clusters_per_group);
3590                        goto failed_mount;
3591                }
3592        } else {
3593                if (clustersize != blocksize) {
3594                        ext4_warning(sb, "fragment/cluster size (%d) != "
3595                                     "block size (%d)", clustersize,
3596                                     blocksize);
3597                        clustersize = blocksize;
3598                }
3599                if (sbi->s_blocks_per_group > blocksize * 8) {
3600                        ext4_msg(sb, KERN_ERR,
3601                                 "#blocks per group too big: %lu",
3602                                 sbi->s_blocks_per_group);
3603                        goto failed_mount;
3604                }
3605                sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3606                sbi->s_cluster_bits = 0;
3607        }
3608        sbi->s_cluster_ratio = clustersize / blocksize;
3609
3610        if (sbi->s_inodes_per_group > blocksize * 8) {
3611                ext4_msg(sb, KERN_ERR,
3612                       "#inodes per group too big: %lu",
3613                       sbi->s_inodes_per_group);
3614                goto failed_mount;
3615        }
3616
3617        /*
3618         * Test whether we have more sectors than will fit in sector_t,
3619         * and whether the max offset is addressable by the page cache.
3620         */
3621        err = generic_check_addressable(sb->s_blocksize_bits,
3622                                        ext4_blocks_count(es));
3623        if (err) {
3624                ext4_msg(sb, KERN_ERR, "filesystem"
3625                         " too large to mount safely on this system");
3626                if (sizeof(sector_t) < 8)
3627                        ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3628                ret = err;
3629                goto failed_mount;
3630        }
3631
3632        if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3633                goto cantfind_ext4;
3634
3635        /* check blocks count against device size */
3636        blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3637        if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3638                ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3639                       "exceeds size of device (%llu blocks)",
3640                       ext4_blocks_count(es), blocks_count);
3641                goto failed_mount;
3642        }
3643
3644        /*
3645         * It makes no sense for the first data block to be beyond the end
3646         * of the filesystem.
3647         */
3648        if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3649                ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3650                         "block %u is beyond end of filesystem (%llu)",
3651                         le32_to_cpu(es->s_first_data_block),
3652                         ext4_blocks_count(es));
3653                goto failed_mount;
3654        }
3655        blocks_count = (ext4_blocks_count(es) -
3656                        le32_to_cpu(es->s_first_data_block) +
3657                        EXT4_BLOCKS_PER_GROUP(sb) - 1);
3658        do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3659        if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3660                ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3661                       "(block count %llu, first data block %u, "
3662                       "blocks per group %lu)", sbi->s_groups_count,
3663                       ext4_blocks_count(es),
3664                       le32_to_cpu(es->s_first_data_block),
3665                       EXT4_BLOCKS_PER_GROUP(sb));
3666                goto failed_mount;
3667        }
3668        sbi->s_groups_count = blocks_count;
3669        sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3670                        (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3671        db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3672                   EXT4_DESC_PER_BLOCK(sb);
3673        sbi->s_group_desc = ext4_kvmalloc(db_count *
3674                                          sizeof(struct buffer_head *),
3675                                          GFP_KERNEL);
3676        if (sbi->s_group_desc == NULL) {
3677                ext4_msg(sb, KERN_ERR, "not enough memory");
3678                ret = -ENOMEM;
3679                goto failed_mount;
3680        }
3681
3682        if (ext4_proc_root)
3683                sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3684
3685        if (sbi->s_proc)
3686                proc_create_data("options", S_IRUGO, sbi->s_proc,
3687                                 &ext4_seq_options_fops, sb);
3688
3689        bgl_lock_init(sbi->s_blockgroup_lock);
3690
3691        for (i = 0; i < db_count; i++) {
3692                block = descriptor_loc(sb, logical_sb_block, i);
3693                sbi->s_group_desc[i] = sb_bread(sb, block);
3694                if (!sbi->s_group_desc[i]) {
3695                        ext4_msg(sb, KERN_ERR,
3696                               "can't read group descriptor %d", i);
3697                        db_count = i;
3698                        goto failed_mount2;
3699                }
3700        }
3701        if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3702                ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3703                goto failed_mount2;
3704        }
3705        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3706                if (!ext4_fill_flex_info(sb)) {
3707                        ext4_msg(sb, KERN_ERR,
3708                               "unable to initialize "
3709                               "flex_bg meta info!");
3710                        goto failed_mount2;
3711                }
3712
3713        sbi->s_gdb_count = db_count;
3714        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3715        spin_lock_init(&sbi->s_next_gen_lock);
3716
3717        init_timer(&sbi->s_err_report);
3718        sbi->s_err_report.function = print_daily_error_info;
3719        sbi->s_err_report.data = (unsigned long) sb;
3720
3721        err = percpu_counter_init(&sbi->s_freeclusters_counter,
3722                        ext4_count_free_clusters(sb));
3723        if (!err) {
3724                err = percpu_counter_init(&sbi->s_freeinodes_counter,
3725                                ext4_count_free_inodes(sb));
3726        }
3727        if (!err) {
3728                err = percpu_counter_init(&sbi->s_dirs_counter,
3729                                ext4_count_dirs(sb));
3730        }
3731        if (!err) {
3732                err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3733        }
3734        if (err) {
3735                ext4_msg(sb, KERN_ERR, "insufficient memory");
3736                ret = err;
3737                goto failed_mount3;
3738        }
3739
3740        sbi->s_stripe = ext4_get_stripe_size(sbi);
3741        sbi->s_max_writeback_mb_bump = 128;
3742
3743        /*
3744         * set up enough so that it can read an inode
3745         */
3746        if (!test_opt(sb, NOLOAD) &&
3747            EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3748                sb->s_op = &ext4_sops;
3749        else
3750                sb->s_op = &ext4_nojournal_sops;
3751        sb->s_export_op = &ext4_export_ops;
3752        sb->s_xattr = ext4_xattr_handlers;
3753#ifdef CONFIG_QUOTA
3754        sb->s_qcop = &ext4_qctl_operations;
3755        sb->dq_op = &ext4_quota_operations;
3756
3757        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3758                /* Use qctl operations for hidden quota files. */
3759                sb->s_qcop = &ext4_qctl_sysfile_operations;
3760        }
3761#endif
3762        memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3763
3764        INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3765        mutex_init(&sbi->s_orphan_lock);
3766        sbi->s_resize_flags = 0;
3767
3768        sb->s_root = NULL;
3769
3770        needs_recovery = (es->s_last_orphan != 0 ||
3771                          EXT4_HAS_INCOMPAT_FEATURE(sb,
3772                                    EXT4_FEATURE_INCOMPAT_RECOVER));
3773
3774        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3775            !(sb->s_flags & MS_RDONLY))
3776                if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3777                        goto failed_mount3;
3778
3779        /*
3780         * The first inode we look at is the journal inode.  Don't try
3781         * root first: it may be modified in the journal!
3782         */
3783        if (!test_opt(sb, NOLOAD) &&
3784            EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3785                if (ext4_load_journal(sb, es, journal_devnum))
3786                        goto failed_mount3;
3787        } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3788              EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3789                ext4_msg(sb, KERN_ERR, "required journal recovery "
3790                       "suppressed and not mounted read-only");
3791                goto failed_mount_wq;
3792        } else {
3793                clear_opt(sb, DATA_FLAGS);
3794                sbi->s_journal = NULL;
3795                needs_recovery = 0;
3796                goto no_journal;
3797        }
3798
3799        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3800            !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3801                                       JBD2_FEATURE_INCOMPAT_64BIT)) {
3802                ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3803                goto failed_mount_wq;
3804        }
3805
3806        if (!set_journal_csum_feature_set(sb)) {
3807                ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3808                         "feature set");
3809                goto failed_mount_wq;
3810        }
3811
3812        /* We have now updated the journal if required, so we can
3813         * validate the data journaling mode. */
3814        switch (test_opt(sb, DATA_FLAGS)) {
3815        case 0:
3816                /* No mode set, assume a default based on the journal
3817                 * capabilities: ORDERED_DATA if the journal can
3818                 * cope, else JOURNAL_DATA
3819                 */
3820                if (jbd2_journal_check_available_features
3821                    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3822                        set_opt(sb, ORDERED_DATA);
3823                else
3824                        set_opt(sb, JOURNAL_DATA);
3825                break;
3826
3827        case EXT4_MOUNT_ORDERED_DATA:
3828        case EXT4_MOUNT_WRITEBACK_DATA:
3829                if (!jbd2_journal_check_available_features
3830                    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3831                        ext4_msg(sb, KERN_ERR, "Journal does not support "
3832                               "requested data journaling mode");
3833                        goto failed_mount_wq;
3834                }
3835        default:
3836                break;
3837        }
3838        set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3839
3840        sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3841
3842        /*
3843         * The journal may have updated the bg summary counts, so we
3844         * need to update the global counters.
3845         */
3846        percpu_counter_set(&sbi->s_freeclusters_counter,
3847                           ext4_count_free_clusters(sb));
3848        percpu_counter_set(&sbi->s_freeinodes_counter,
3849                           ext4_count_free_inodes(sb));
3850        percpu_counter_set(&sbi->s_dirs_counter,
3851                           ext4_count_dirs(sb));
3852        percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3853
3854no_journal:
3855        /*
3856         * Get the # of file system overhead blocks from the
3857         * superblock if present.
3858         */
3859        if (es->s_overhead_clusters)
3860                sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3861        else {
3862                ret = ext4_calculate_overhead(sb);
3863                if (ret)
3864                        goto failed_mount_wq;
3865        }
3866
3867        /*
3868         * The maximum number of concurrent works can be high and
3869         * concurrency isn't really necessary.  Limit it to 1.
3870         */
3871        EXT4_SB(sb)->dio_unwritten_wq =
3872                alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3873        if (!EXT4_SB(sb)->dio_unwritten_wq) {
3874                printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3875                goto failed_mount_wq;
3876        }
3877
3878        /*
3879         * The jbd2_journal_load will have done any necessary log recovery,
3880         * so we can safely mount the rest of the filesystem now.
3881         */
3882
3883        root = ext4_iget(sb, EXT4_ROOT_INO);
3884        if (IS_ERR(root)) {
3885                ext4_msg(sb, KERN_ERR, "get root inode failed");
3886                ret = PTR_ERR(root);
3887                root = NULL;
3888                goto failed_mount4;
3889        }
3890        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3891                ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3892                iput(root);
3893                goto failed_mount4;
3894        }
3895        sb->s_root = d_make_root(root);
3896        if (!sb->s_root) {
3897                ext4_msg(sb, KERN_ERR, "get root dentry failed");
3898                ret = -ENOMEM;
3899                goto failed_mount4;
3900        }
3901
3902        if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3903                sb->s_flags |= MS_RDONLY;
3904
3905        /* determine the minimum size of new large inodes, if present */
3906        if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3907                sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3908                                                     EXT4_GOOD_OLD_INODE_SIZE;
3909                if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3910                                       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3911                        if (sbi->s_want_extra_isize <
3912                            le16_to_cpu(es->s_want_extra_isize))
3913                                sbi->s_want_extra_isize =
3914                                        le16_to_cpu(es->s_want_extra_isize);
3915                        if (sbi->s_want_extra_isize <
3916                            le16_to_cpu(es->s_min_extra_isize))
3917                                sbi->s_want_extra_isize =
3918                                        le16_to_cpu(es->s_min_extra_isize);
3919                }
3920        }
3921        /* Check if enough inode space is available */
3922        if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3923                                                        sbi->s_inode_size) {
3924                sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3925                                                       EXT4_GOOD_OLD_INODE_SIZE;
3926                ext4_msg(sb, KERN_INFO, "required extra inode space not"
3927                         "available");
3928        }
3929
3930        err = ext4_setup_system_zone(sb);
3931        if (err) {
3932                ext4_msg(sb, KERN_ERR, "failed to initialize system "
3933                         "zone (%d)", err);
3934                goto failed_mount4a;
3935        }
3936
3937        ext4_ext_init(sb);
3938        err = ext4_mb_init(sb);
3939        if (err) {
3940                ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3941                         err);
3942                goto failed_mount5;
3943        }
3944
3945        err = ext4_register_li_request(sb, first_not_zeroed);
3946        if (err)
3947                goto failed_mount6;
3948
3949        sbi->s_kobj.kset = ext4_kset;
3950        init_completion(&sbi->s_kobj_unregister);
3951        err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3952                                   "%s", sb->s_id);
3953        if (err)
3954                goto failed_mount7;
3955
3956        EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3957        ext4_orphan_cleanup(sb, es);
3958        EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3959        if (needs_recovery) {
3960                ext4_msg(sb, KERN_INFO, "recovery complete");
3961                ext4_mark_recovery_complete(sb, es);
3962        }
3963        if (EXT4_SB(sb)->s_journal) {
3964                if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3965                        descr = " journalled data mode";
3966                else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3967                        descr = " ordered data mode";
3968                else
3969                        descr = " writeback data mode";
3970        } else
3971                descr = "out journal";
3972
3973#ifdef CONFIG_QUOTA
3974        /* Enable quota usage during mount. */
3975        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
3976            !(sb->s_flags & MS_RDONLY)) {
3977                ret = ext4_enable_quotas(sb);
3978                if (ret)
3979                        goto failed_mount7;
3980        }
3981#endif  /* CONFIG_QUOTA */
3982
3983        ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3984                 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3985                 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3986
3987        if (es->s_error_count)
3988                mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3989
3990        kfree(orig_data);
3991        return 0;
3992
3993cantfind_ext4:
3994        if (!silent)
3995                ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3996        goto failed_mount;
3997
3998failed_mount7:
3999        ext4_unregister_li_request(sb);
4000failed_mount6:
4001        ext4_mb_release(sb);
4002failed_mount5:
4003        ext4_ext_release(sb);
4004        ext4_release_system_zone(sb);
4005failed_mount4a:
4006        dput(sb->s_root);
4007        sb->s_root = NULL;
4008failed_mount4:
4009        ext4_msg(sb, KERN_ERR, "mount failed");
4010        destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4011failed_mount_wq:
4012        if (sbi->s_journal) {
4013                jbd2_journal_destroy(sbi->s_journal);
4014                sbi->s_journal = NULL;
4015        }
4016failed_mount3:
4017        del_timer(&sbi->s_err_report);
4018        if (sbi->s_flex_groups)
4019                ext4_kvfree(sbi->s_flex_groups);
4020        percpu_counter_destroy(&sbi->s_freeclusters_counter);
4021        percpu_counter_destroy(&sbi->s_freeinodes_counter);
4022        percpu_counter_destroy(&sbi->s_dirs_counter);
4023        percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4024        if (sbi->s_mmp_tsk)
4025                kthread_stop(sbi->s_mmp_tsk);
4026failed_mount2:
4027        for (i = 0; i < db_count; i++)
4028                brelse(sbi->s_group_desc[i]);
4029        ext4_kvfree(sbi->s_group_desc);
4030failed_mount:
4031        if (sbi->s_chksum_driver)
4032                crypto_free_shash(sbi->s_chksum_driver);
4033        if (sbi->s_proc) {
4034                remove_proc_entry("options", sbi->s_proc);
4035                remove_proc_entry(sb->s_id, ext4_proc_root);
4036        }
4037#ifdef CONFIG_QUOTA
4038        for (i = 0; i < MAXQUOTAS; i++)
4039                kfree(sbi->s_qf_names[i]);
4040#endif
4041        ext4_blkdev_remove(sbi);
4042        brelse(bh);
4043out_fail:
4044        sb->s_fs_info = NULL;
4045        kfree(sbi->s_blockgroup_lock);
4046        kfree(sbi);
4047out_free_orig:
4048        kfree(orig_data);
4049        return ret;
4050}
4051
4052/*
4053 * Setup any per-fs journal parameters now.  We'll do this both on
4054 * initial mount, once the journal has been initialised but before we've
4055 * done any recovery; and again on any subsequent remount.
4056 */
4057static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4058{
4059        struct ext4_sb_info *sbi = EXT4_SB(sb);
4060
4061        journal->j_commit_interval = sbi->s_commit_interval;
4062        journal->j_min_batch_time = sbi->s_min_batch_time;
4063        journal->j_max_batch_time = sbi->s_max_batch_time;
4064
4065        write_lock(&journal->j_state_lock);
4066        if (test_opt(sb, BARRIER))
4067                journal->j_flags |= JBD2_BARRIER;
4068        else
4069                journal->j_flags &= ~JBD2_BARRIER;
4070        if (test_opt(sb, DATA_ERR_ABORT))
4071                journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4072        else
4073                journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4074        write_unlock(&journal->j_state_lock);
4075}
4076
4077static journal_t *ext4_get_journal(struct super_block *sb,
4078                                   unsigned int journal_inum)
4079{
4080        struct inode *journal_inode;
4081        journal_t *journal;
4082
4083        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4084
4085        /* First, test for the existence of a valid inode on disk.  Bad
4086         * things happen if we iget() an unused inode, as the subsequent
4087         * iput() will try to delete it. */
4088
4089        journal_inode = ext4_iget(sb, journal_inum);
4090        if (IS_ERR(journal_inode)) {
4091                ext4_msg(sb, KERN_ERR, "no journal found");
4092                return NULL;
4093        }
4094        if (!journal_inode->i_nlink) {
4095                make_bad_inode(journal_inode);
4096                iput(journal_inode);
4097                ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4098                return NULL;
4099        }
4100
4101        jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4102                  journal_inode, journal_inode->i_size);
4103        if (!S_ISREG(journal_inode->i_mode)) {
4104                ext4_msg(sb, KERN_ERR, "invalid journal inode");
4105                iput(journal_inode);
4106                return NULL;
4107        }
4108
4109        journal = jbd2_journal_init_inode(journal_inode);
4110        if (!journal) {
4111                ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4112                iput(journal_inode);
4113                return NULL;
4114        }
4115        journal->j_private = sb;
4116        ext4_init_journal_params(sb, journal);
4117        return journal;
4118}
4119
4120static journal_t *ext4_get_dev_journal(struct super_block *sb,
4121                                       dev_t j_dev)
4122{
4123        struct buffer_head *bh;
4124        journal_t *journal;
4125        ext4_fsblk_t start;
4126        ext4_fsblk_t len;
4127        int hblock, blocksize;
4128        ext4_fsblk_t sb_block;
4129        unsigned long offset;
4130        struct ext4_super_block *es;
4131        struct block_device *bdev;
4132
4133        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4134
4135        bdev = ext4_blkdev_get(j_dev, sb);
4136        if (bdev == NULL)
4137                return NULL;
4138
4139        blocksize = sb->s_blocksize;
4140        hblock = bdev_logical_block_size(bdev);
4141        if (blocksize < hblock) {
4142                ext4_msg(sb, KERN_ERR,
4143                        "blocksize too small for journal device");
4144                goto out_bdev;
4145        }
4146
4147        sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4148        offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4149        set_blocksize(bdev, blocksize);
4150        if (!(bh = __bread(bdev, sb_block, blocksize))) {
4151                ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4152                       "external journal");
4153                goto out_bdev;
4154        }
4155
4156        es = (struct ext4_super_block *) (bh->b_data + offset);
4157        if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4158            !(le32_to_cpu(es->s_feature_incompat) &
4159              EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4160                ext4_msg(sb, KERN_ERR, "external journal has "
4161                                        "bad superblock");
4162                brelse(bh);
4163                goto out_bdev;
4164        }
4165
4166        if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4167                ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4168                brelse(bh);
4169                goto out_bdev;
4170        }
4171
4172        len = ext4_blocks_count(es);
4173        start = sb_block + 1;
4174        brelse(bh);     /* we're done with the superblock */
4175
4176        journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4177                                        start, len, blocksize);
4178        if (!journal) {
4179                ext4_msg(sb, KERN_ERR, "failed to create device journal");
4180                goto out_bdev;
4181        }
4182        journal->j_private = sb;
4183        ll_rw_block(READ, 1, &journal->j_sb_buffer);
4184        wait_on_buffer(journal->j_sb_buffer);
4185        if (!buffer_uptodate(journal->j_sb_buffer)) {
4186                ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4187                goto out_journal;
4188        }
4189        if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4190                ext4_msg(sb, KERN_ERR, "External journal has more than one "
4191                                        "user (unsupported) - %d",
4192                        be32_to_cpu(journal->j_superblock->s_nr_users));
4193                goto out_journal;
4194        }
4195        EXT4_SB(sb)->journal_bdev = bdev;
4196        ext4_init_journal_params(sb, journal);
4197        return journal;
4198
4199out_journal:
4200        jbd2_journal_destroy(journal);
4201out_bdev:
4202        ext4_blkdev_put(bdev);
4203        return NULL;
4204}
4205
4206static int ext4_load_journal(struct super_block *sb,
4207                             struct ext4_super_block *es,
4208                             unsigned long journal_devnum)
4209{
4210        journal_t *journal;
4211        unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4212        dev_t journal_dev;
4213        int err = 0;
4214        int really_read_only;
4215
4216        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4217
4218        if (journal_devnum &&
4219            journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4220                ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4221                        "numbers have changed");
4222                journal_dev = new_decode_dev(journal_devnum);
4223        } else
4224                journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4225
4226        really_read_only = bdev_read_only(sb->s_bdev);
4227
4228        /*
4229         * Are we loading a blank journal or performing recovery after a
4230         * crash?  For recovery, we need to check in advance whether we
4231         * can get read-write access to the device.
4232         */
4233        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4234                if (sb->s_flags & MS_RDONLY) {
4235                        ext4_msg(sb, KERN_INFO, "INFO: recovery "
4236                                        "required on readonly filesystem");
4237                        if (really_read_only) {
4238                                ext4_msg(sb, KERN_ERR, "write access "
4239                                        "unavailable, cannot proceed");
4240                                return -EROFS;
4241                        }
4242                        ext4_msg(sb, KERN_INFO, "write access will "
4243                               "be enabled during recovery");
4244                }
4245        }
4246
4247        if (journal_inum && journal_dev) {
4248                ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4249                       "and inode journals!");
4250                return -EINVAL;
4251        }
4252
4253        if (journal_inum) {
4254                if (!(journal = ext4_get_journal(sb, journal_inum)))
4255                        return -EINVAL;
4256        } else {
4257                if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4258                        return -EINVAL;
4259        }
4260
4261        if (!(journal->j_flags & JBD2_BARRIER))
4262                ext4_msg(sb, KERN_INFO, "barriers disabled");
4263
4264        if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4265                err = jbd2_journal_wipe(journal, !really_read_only);
4266        if (!err) {
4267                char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4268                if (save)
4269                        memcpy(save, ((char *) es) +
4270                               EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4271                err = jbd2_journal_load(journal);
4272                if (save)
4273                        memcpy(((char *) es) + EXT4_S_ERR_START,
4274                               save, EXT4_S_ERR_LEN);
4275                kfree(save);
4276        }
4277
4278        if (err) {
4279                ext4_msg(sb, KERN_ERR, "error loading journal");
4280                jbd2_journal_destroy(journal);
4281                return err;
4282        }
4283
4284        EXT4_SB(sb)->s_journal = journal;
4285        ext4_clear_journal_err(sb, es);
4286
4287        if (!really_read_only && journal_devnum &&
4288            journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4289                es->s_journal_dev = cpu_to_le32(journal_devnum);
4290
4291                /* Make sure we flush the recovery flag to disk. */
4292                ext4_commit_super(sb, 1);
4293        }
4294
4295        return 0;
4296}
4297
4298static int ext4_commit_super(struct super_block *sb, int sync)
4299{
4300        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4301        struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4302        int error = 0;
4303
4304        if (!sbh || block_device_ejected(sb))
4305                return error;
4306        if (buffer_write_io_error(sbh)) {
4307                /*
4308                 * Oh, dear.  A previous attempt to write the
4309                 * superblock failed.  This could happen because the
4310                 * USB device was yanked out.  Or it could happen to
4311                 * be a transient write error and maybe the block will
4312                 * be remapped.  Nothing we can do but to retry the
4313                 * write and hope for the best.
4314                 */
4315                ext4_msg(sb, KERN_ERR, "previous I/O error to "
4316                       "superblock detected");
4317                clear_buffer_write_io_error(sbh);
4318                set_buffer_uptodate(sbh);
4319        }
4320        /*
4321         * If the file system is mounted read-only, don't update the
4322         * superblock write time.  This avoids updating the superblock
4323         * write time when we are mounting the root file system
4324         * read/only but we need to replay the journal; at that point,
4325         * for people who are east of GMT and who make their clock
4326         * tick in localtime for Windows bug-for-bug compatibility,
4327         * the clock is set in the future, and this will cause e2fsck
4328         * to complain and force a full file system check.
4329         */
4330        if (!(sb->s_flags & MS_RDONLY))
4331                es->s_wtime = cpu_to_le32(get_seconds());
4332        if (sb->s_bdev->bd_part)
4333                es->s_kbytes_written =
4334                        cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4335                            ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4336                              EXT4_SB(sb)->s_sectors_written_start) >> 1));
4337        else
4338                es->s_kbytes_written =
4339                        cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4340        ext4_free_blocks_count_set(es,
4341                        EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4342                                &EXT4_SB(sb)->s_freeclusters_counter)));
4343        es->s_free_inodes_count =
4344                cpu_to_le32(percpu_counter_sum_positive(
4345                                &EXT4_SB(sb)->s_freeinodes_counter));
4346        BUFFER_TRACE(sbh, "marking dirty");
4347        ext4_superblock_csum_set(sb);
4348        mark_buffer_dirty(sbh);
4349        if (sync) {
4350                error = sync_dirty_buffer(sbh);
4351                if (error)
4352                        return error;
4353
4354                error = buffer_write_io_error(sbh);
4355                if (error) {
4356                        ext4_msg(sb, KERN_ERR, "I/O error while writing "
4357                               "superblock");
4358                        clear_buffer_write_io_error(sbh);
4359                        set_buffer_uptodate(sbh);
4360                }
4361        }
4362        return error;
4363}
4364
4365/*
4366 * Have we just finished recovery?  If so, and if we are mounting (or
4367 * remounting) the filesystem readonly, then we will end up with a
4368 * consistent fs on disk.  Record that fact.
4369 */
4370static void ext4_mark_recovery_complete(struct super_block *sb,
4371                                        struct ext4_super_block *es)
4372{
4373        journal_t *journal = EXT4_SB(sb)->s_journal;
4374
4375        if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4376                BUG_ON(journal != NULL);
4377                return;
4378        }
4379        jbd2_journal_lock_updates(journal);
4380        if (jbd2_journal_flush(journal) < 0)
4381                goto out;
4382
4383        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4384            sb->s_flags & MS_RDONLY) {
4385                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4386                ext4_commit_super(sb, 1);
4387        }
4388
4389out:
4390        jbd2_journal_unlock_updates(journal);
4391}
4392
4393/*
4394 * If we are mounting (or read-write remounting) a filesystem whose journal
4395 * has recorded an error from a previous lifetime, move that error to the
4396 * main filesystem now.
4397 */
4398static void ext4_clear_journal_err(struct super_block *sb,
4399                                   struct ext4_super_block *es)
4400{
4401        journal_t *journal;
4402        int j_errno;
4403        const char *errstr;
4404
4405        BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4406
4407        journal = EXT4_SB(sb)->s_journal;
4408
4409        /*
4410         * Now check for any error status which may have been recorded in the
4411         * journal by a prior ext4_error() or ext4_abort()
4412         */
4413
4414        j_errno = jbd2_journal_errno(journal);
4415        if (j_errno) {
4416                char nbuf[16];
4417
4418                errstr = ext4_decode_error(sb, j_errno, nbuf);
4419                ext4_warning(sb, "Filesystem error recorded "
4420                             "from previous mount: %s", errstr);
4421                ext4_warning(sb, "Marking fs in need of filesystem check.");
4422
4423                EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4424                es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4425                ext4_commit_super(sb, 1);
4426
4427                jbd2_journal_clear_err(journal);
4428                jbd2_journal_update_sb_errno(journal);
4429        }
4430}
4431
4432/*
4433 * Force the running and committing transactions to commit,
4434 * and wait on the commit.
4435 */
4436int ext4_force_commit(struct super_block *sb)
4437{
4438        journal_t *journal;
4439        int ret = 0;
4440
4441        if (sb->s_flags & MS_RDONLY)
4442                return 0;
4443
4444        journal = EXT4_SB(sb)->s_journal;
4445        if (journal)
4446                ret = ext4_journal_force_commit(journal);
4447
4448        return ret;
4449}
4450
4451static int ext4_sync_fs(struct super_block *sb, int wait)
4452{
4453        int ret = 0;
4454        tid_t target;
4455        struct ext4_sb_info *sbi = EXT4_SB(sb);
4456
4457        trace_ext4_sync_fs(sb, wait);
4458        flush_workqueue(sbi->dio_unwritten_wq);
4459        /*
4460         * Writeback quota in non-journalled quota case - journalled quota has
4461         * no dirty dquots
4462         */
4463        dquot_writeback_dquots(sb, -1);
4464        if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4465                if (wait)
4466                        jbd2_log_wait_commit(sbi->s_journal, target);
4467        }
4468        return ret;
4469}
4470
4471/*
4472 * LVM calls this function before a (read-only) snapshot is created.  This
4473 * gives us a chance to flush the journal completely and mark the fs clean.
4474 *
4475 * Note that only this function cannot bring a filesystem to be in a clean
4476 * state independently. It relies on upper layer to stop all data & metadata
4477 * modifications.
4478 */
4479static int ext4_freeze(struct super_block *sb)
4480{
4481        int error = 0;
4482        journal_t *journal;
4483
4484        if (sb->s_flags & MS_RDONLY)
4485                return 0;
4486
4487        journal = EXT4_SB(sb)->s_journal;
4488
4489        /* Now we set up the journal barrier. */
4490        jbd2_journal_lock_updates(journal);
4491
4492        /*
4493         * Don't clear the needs_recovery flag if we failed to flush
4494         * the journal.
4495         */
4496        error = jbd2_journal_flush(journal);
4497        if (error < 0)
4498                goto out;
4499
4500        /* Journal blocked and flushed, clear needs_recovery flag. */
4501        EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4502        error = ext4_commit_super(sb, 1);
4503out:
4504        /* we rely on upper layer to stop further updates */
4505        jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4506        return error;
4507}
4508
4509/*
4510 * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4511 * flag here, even though the filesystem is not technically dirty yet.
4512 */
4513static int ext4_unfreeze(struct super_block *sb)
4514{
4515        if (sb->s_flags & MS_RDONLY)
4516                return 0;
4517
4518        lock_super(sb);
4519        /* Reset the needs_recovery flag before the fs is unlocked. */
4520        EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4521        ext4_commit_super(sb, 1);
4522        unlock_super(sb);
4523        return 0;
4524}
4525
4526/*
4527 * Structure to save mount options for ext4_remount's benefit
4528 */
4529struct ext4_mount_options {
4530        unsigned long s_mount_opt;
4531        unsigned long s_mount_opt2;
4532        kuid_t s_resuid;
4533        kgid_t s_resgid;
4534        unsigned long s_commit_interval;
4535        u32 s_min_batch_time, s_max_batch_time;
4536#ifdef CONFIG_QUOTA
4537        int s_jquota_fmt;
4538        char *s_qf_names[MAXQUOTAS];
4539#endif
4540};
4541
4542static int ext4_remount(struct super_block *sb, int *flags, char *data)
4543{
4544        struct ext4_super_block *es;
4545        struct ext4_sb_info *sbi = EXT4_SB(sb);
4546        unsigned long old_sb_flags;
4547        struct ext4_mount_options old_opts;
4548        int enable_quota = 0;
4549        ext4_group_t g;
4550        unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4551        int err = 0;
4552#ifdef CONFIG_QUOTA
4553        int i;
4554#endif
4555        char *orig_data = kstrdup(data, GFP_KERNEL);
4556
4557        /* Store the original options */
4558        lock_super(sb);
4559        old_sb_flags = sb->s_flags;
4560        old_opts.s_mount_opt = sbi->s_mount_opt;
4561        old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4562        old_opts.s_resuid = sbi->s_resuid;
4563        old_opts.s_resgid = sbi->s_resgid;
4564        old_opts.s_commit_interval = sbi->s_commit_interval;
4565        old_opts.s_min_batch_time = sbi->s_min_batch_time;
4566        old_opts.s_max_batch_time = sbi->s_max_batch_time;
4567#ifdef CONFIG_QUOTA
4568        old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4569        for (i = 0; i < MAXQUOTAS; i++)
4570                old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4571#endif
4572        if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4573                journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4574
4575        /*
4576         * Allow the "check" option to be passed as a remount option.
4577         */
4578        if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4579                err = -EINVAL;
4580                goto restore_opts;
4581        }
4582
4583        if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4584                ext4_abort(sb, "Abort forced by user");
4585
4586        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4587                (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4588
4589        es = sbi->s_es;
4590
4591        if (sbi->s_journal) {
4592                ext4_init_journal_params(sb, sbi->s_journal);
4593                set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4594        }
4595
4596        if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4597                if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4598                        err = -EROFS;
4599                        goto restore_opts;
4600                }
4601
4602                if (*flags & MS_RDONLY) {
4603                        err = dquot_suspend(sb, -1);
4604                        if (err < 0)
4605                                goto restore_opts;
4606
4607                        /*
4608                         * First of all, the unconditional stuff we have to do
4609                         * to disable replay of the journal when we next remount
4610                         */
4611                        sb->s_flags |= MS_RDONLY;
4612
4613                        /*
4614                         * OK, test if we are remounting a valid rw partition
4615                         * readonly, and if so set the rdonly flag and then
4616                         * mark the partition as valid again.
4617                         */
4618                        if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4619                            (sbi->s_mount_state & EXT4_VALID_FS))
4620                                es->s_state = cpu_to_le16(sbi->s_mount_state);
4621
4622                        if (sbi->s_journal)
4623                                ext4_mark_recovery_complete(sb, es);
4624                } else {
4625                        /* Make sure we can mount this feature set readwrite */
4626                        if (!ext4_feature_set_ok(sb, 0)) {
4627                                err = -EROFS;
4628                                goto restore_opts;
4629                        }
4630                        /*
4631                         * Make sure the group descriptor checksums
4632                         * are sane.  If they aren't, refuse to remount r/w.
4633                         */
4634                        for (g = 0; g < sbi->s_groups_count; g++) {
4635                                struct ext4_group_desc *gdp =
4636                                        ext4_get_group_desc(sb, g, NULL);
4637
4638                                if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4639                                        ext4_msg(sb, KERN_ERR,
4640               "ext4_remount: Checksum for group %u failed (%u!=%u)",
4641                g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4642                                               le16_to_cpu(gdp->bg_checksum));
4643                                        err = -EINVAL;
4644                                        goto restore_opts;
4645                                }
4646                        }
4647
4648                        /*
4649                         * If we have an unprocessed orphan list hanging
4650                         * around from a previously readonly bdev mount,
4651                         * require a full umount/remount for now.
4652                         */
4653                        if (es->s_last_orphan) {
4654                                ext4_msg(sb, KERN_WARNING, "Couldn't "
4655                                       "remount RDWR because of unprocessed "
4656                                       "orphan inode list.  Please "
4657                                       "umount/remount instead");
4658                                err = -EINVAL;
4659                                goto restore_opts;
4660                        }
4661
4662                        /*
4663                         * Mounting a RDONLY partition read-write, so reread
4664                         * and store the current valid flag.  (It may have
4665                         * been changed by e2fsck since we originally mounted
4666                         * the partition.)
4667                         */
4668                        if (sbi->s_journal)
4669                                ext4_clear_journal_err(sb, es);
4670                        sbi->s_mount_state = le16_to_cpu(es->s_state);
4671                        if (!ext4_setup_super(sb, es, 0))
4672                                sb->s_flags &= ~MS_RDONLY;
4673                        if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4674                                                     EXT4_FEATURE_INCOMPAT_MMP))
4675                                if (ext4_multi_mount_protect(sb,
4676                                                le64_to_cpu(es->s_mmp_block))) {
4677                                        err = -EROFS;
4678                                        goto restore_opts;
4679                                }
4680                        enable_quota = 1;
4681                }
4682        }
4683
4684        /*
4685         * Reinitialize lazy itable initialization thread based on
4686         * current settings
4687         */
4688        if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4689                ext4_unregister_li_request(sb);
4690        else {
4691                ext4_group_t first_not_zeroed;
4692                first_not_zeroed = ext4_has_uninit_itable(sb);
4693                ext4_register_li_request(sb, first_not_zeroed);
4694        }
4695
4696        ext4_setup_system_zone(sb);
4697        if (sbi->s_journal == NULL)
4698                ext4_commit_super(sb, 1);
4699
4700        unlock_super(sb);
4701#ifdef CONFIG_QUOTA
4702        /* Release old quota file names */
4703        for (i = 0; i < MAXQUOTAS; i++)
4704                if (old_opts.s_qf_names[i] &&
4705                    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4706                        kfree(old_opts.s_qf_names[i]);
4707        if (enable_quota) {
4708                if (sb_any_quota_suspended(sb))
4709                        dquot_resume(sb, -1);
4710                else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4711                                        EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4712                        err = ext4_enable_quotas(sb);
4713                        if (err) {
4714                                lock_super(sb);
4715                                goto restore_opts;
4716                        }
4717                }
4718        }
4719#endif
4720
4721        ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4722        kfree(orig_data);
4723        return 0;
4724
4725restore_opts:
4726        sb->s_flags = old_sb_flags;
4727        sbi->s_mount_opt = old_opts.s_mount_opt;
4728        sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4729        sbi->s_resuid = old_opts.s_resuid;
4730        sbi->s_resgid = old_opts.s_resgid;
4731        sbi->s_commit_interval = old_opts.s_commit_interval;
4732        sbi->s_min_batch_time = old_opts.s_min_batch_time;
4733        sbi->s_max_batch_time = old_opts.s_max_batch_time;
4734#ifdef CONFIG_QUOTA
4735        sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4736        for (i = 0; i < MAXQUOTAS; i++) {
4737                if (sbi->s_qf_names[i] &&
4738                    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4739                        kfree(sbi->s_qf_names[i]);
4740                sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4741        }
4742#endif
4743        unlock_super(sb);
4744        kfree(orig_data);
4745        return err;
4746}
4747
4748static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4749{
4750        struct super_block *sb = dentry->d_sb;
4751        struct ext4_sb_info *sbi = EXT4_SB(sb);
4752        struct ext4_super_block *es = sbi->s_es;
4753        ext4_fsblk_t overhead = 0;
4754        u64 fsid;
4755        s64 bfree;
4756
4757        if (!test_opt(sb, MINIX_DF))
4758                overhead = sbi->s_overhead;
4759
4760        buf->f_type = EXT4_SUPER_MAGIC;
4761        buf->f_bsize = sb->s_blocksize;
4762        buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
4763        bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4764                percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4765        /* prevent underflow in case that few free space is available */
4766        buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4767        buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4768        if (buf->f_bfree < ext4_r_blocks_count(es))
4769                buf->f_bavail = 0;
4770        buf->f_files = le32_to_cpu(es->s_inodes_count);
4771        buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4772        buf->f_namelen = EXT4_NAME_LEN;
4773        fsid = le64_to_cpup((void *)es->s_uuid) ^
4774               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4775        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4776        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4777
4778        return 0;
4779}
4780
4781/* Helper function for writing quotas on sync - we need to start transaction
4782 * before quota file is locked for write. Otherwise the are possible deadlocks:
4783 * Process 1                         Process 2
4784 * ext4_create()                     quota_sync()
4785 *   jbd2_journal_start()                  write_dquot()
4786 *   dquot_initialize()                         down(dqio_mutex)
4787 *     down(dqio_mutex)                    jbd2_journal_start()
4788 *
4789 */
4790
4791#ifdef CONFIG_QUOTA
4792
4793static inline struct inode *dquot_to_inode(struct dquot *dquot)
4794{
4795        return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4796}
4797
4798static int ext4_write_dquot(struct dquot *dquot)
4799{
4800        int ret, err;
4801        handle_t *handle;
4802        struct inode *inode;
4803
4804        inode = dquot_to_inode(dquot);
4805        handle = ext4_journal_start(inode,
4806                                    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4807        if (IS_ERR(handle))
4808                return PTR_ERR(handle);
4809        ret = dquot_commit(dquot);
4810        err = ext4_journal_stop(handle);
4811        if (!ret)
4812                ret = err;
4813        return ret;
4814}
4815
4816static int ext4_acquire_dquot(struct dquot *dquot)
4817{
4818        int ret, err;
4819        handle_t *handle;
4820
4821        handle = ext4_journal_start(dquot_to_inode(dquot),
4822                                    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4823        if (IS_ERR(handle))
4824                return PTR_ERR(handle);
4825        ret = dquot_acquire(dquot);
4826        err = ext4_journal_stop(handle);
4827        if (!ret)
4828                ret = err;
4829        return ret;
4830}
4831
4832static int ext4_release_dquot(struct dquot *dquot)
4833{
4834        int ret, err;
4835        handle_t *handle;
4836
4837        handle = ext4_journal_start(dquot_to_inode(dquot),
4838                                    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4839        if (IS_ERR(handle)) {
4840                /* Release dquot anyway to avoid endless cycle in dqput() */
4841                dquot_release(dquot);
4842                return PTR_ERR(handle);
4843        }
4844        ret = dquot_release(dquot);
4845        err = ext4_journal_stop(handle);
4846        if (!ret)
4847                ret = err;
4848        return ret;
4849}
4850
4851static int ext4_mark_dquot_dirty(struct dquot *dquot)
4852{
4853        /* Are we journaling quotas? */
4854        if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4855            EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4856                dquot_mark_dquot_dirty(dquot);
4857                return ext4_write_dquot(dquot);
4858        } else {
4859                return dquot_mark_dquot_dirty(dquot);
4860        }
4861}
4862
4863static int ext4_write_info(struct super_block *sb, int type)
4864{
4865        int ret, err;
4866        handle_t *handle;
4867
4868        /* Data block + inode block */
4869        handle = ext4_journal_start(sb->s_root->d_inode, 2);
4870        if (IS_ERR(handle))
4871                return PTR_ERR(handle);
4872        ret = dquot_commit_info(sb, type);
4873        err = ext4_journal_stop(handle);
4874        if (!ret)
4875                ret = err;
4876        return ret;
4877}
4878
4879/*
4880 * Turn on quotas during mount time - we need to find
4881 * the quota file and such...
4882 */
4883static int ext4_quota_on_mount(struct super_block *sb, int type)
4884{
4885        return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4886                                        EXT4_SB(sb)->s_jquota_fmt, type);
4887}
4888
4889/*
4890 * Standard function to be called on quota_on
4891 */
4892static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4893                         struct path *path)
4894{
4895        int err;
4896
4897        if (!test_opt(sb, QUOTA))
4898                return -EINVAL;
4899
4900        /* Quotafile not on the same filesystem? */
4901        if (path->dentry->d_sb != sb)
4902                return -EXDEV;
4903        /* Journaling quota? */
4904        if (EXT4_SB(sb)->s_qf_names[type]) {
4905                /* Quotafile not in fs root? */
4906                if (path->dentry->d_parent != sb->s_root)
4907                        ext4_msg(sb, KERN_WARNING,
4908                                "Quota file not on filesystem root. "
4909                                "Journaled quota will not work");
4910        }
4911
4912        /*
4913         * When we journal data on quota file, we have to flush journal to see
4914         * all updates to the file when we bypass pagecache...
4915         */
4916        if (EXT4_SB(sb)->s_journal &&
4917            ext4_should_journal_data(path->dentry->d_inode)) {
4918                /*
4919                 * We don't need to lock updates but journal_flush() could
4920                 * otherwise be livelocked...
4921                 */
4922                jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4923                err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4924                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4925                if (err)
4926                        return err;
4927        }
4928
4929        return dquot_quota_on(sb, type, format_id, path);
4930}
4931
4932static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4933                             unsigned int flags)
4934{
4935        int err;
4936        struct inode *qf_inode;
4937        unsigned long qf_inums[MAXQUOTAS] = {
4938                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4939                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4940        };
4941
4942        BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4943
4944        if (!qf_inums[type])
4945                return -EPERM;
4946
4947        qf_inode = ext4_iget(sb, qf_inums[type]);
4948        if (IS_ERR(qf_inode)) {
4949                ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4950                return PTR_ERR(qf_inode);
4951        }
4952
4953        err = dquot_enable(qf_inode, type, format_id, flags);
4954        iput(qf_inode);
4955
4956        return err;
4957}
4958
4959/* Enable usage tracking for all quota types. */
4960static int ext4_enable_quotas(struct super_block *sb)
4961{
4962        int type, err = 0;
4963        unsigned long qf_inums[MAXQUOTAS] = {
4964                le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4965                le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4966        };
4967
4968        sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
4969        for (type = 0; type < MAXQUOTAS; type++) {
4970                if (qf_inums[type]) {
4971                        err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
4972                                                DQUOT_USAGE_ENABLED);
4973                        if (err) {
4974                                ext4_warning(sb,
4975                                        "Failed to enable quota (type=%d) "
4976                                        "tracking. Please run e2fsck to fix.",
4977                                        type);
4978                                return err;
4979                        }
4980                }
4981        }
4982        return 0;
4983}
4984
4985/*
4986 * quota_on function that is used when QUOTA feature is set.
4987 */
4988static int ext4_quota_on_sysfile(struct super_block *sb, int type,
4989                                 int format_id)
4990{
4991        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4992                return -EINVAL;
4993
4994        /*
4995         * USAGE was enabled at mount time. Only need to enable LIMITS now.
4996         */
4997        return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
4998}
4999
5000static int ext4_quota_off(struct super_block *sb, int type)
5001{
5002        struct inode *inode = sb_dqopt(sb)->files[type];
5003        handle_t *handle;
5004
5005        /* Force all delayed allocation blocks to be allocated.
5006         * Caller already holds s_umount sem */
5007        if (test_opt(sb, DELALLOC))
5008                sync_filesystem(sb);
5009
5010        if (!inode)
5011                goto out;
5012
5013        /* Update modification times of quota files when userspace can
5014         * start looking at them */
5015        handle = ext4_journal_start(inode, 1);
5016        if (IS_ERR(handle))
5017                goto out;
5018        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5019        ext4_mark_inode_dirty(handle, inode);
5020        ext4_journal_stop(handle);
5021
5022out:
5023        return dquot_quota_off(sb, type);
5024}
5025
5026/*
5027 * quota_off function that is used when QUOTA feature is set.
5028 */
5029static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5030{
5031        if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5032                return -EINVAL;
5033
5034        /* Disable only the limits. */
5035        return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5036}
5037
5038/* Read data from quotafile - avoid pagecache and such because we cannot afford
5039 * acquiring the locks... As quota files are never truncated and quota code
5040 * itself serializes the operations (and no one else should touch the files)
5041 * we don't have to be afraid of races */
5042static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5043                               size_t len, loff_t off)
5044{
5045        struct inode *inode = sb_dqopt(sb)->files[type];
5046        ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5047        int err = 0;
5048        int offset = off & (sb->s_blocksize - 1);
5049        int tocopy;
5050        size_t toread;
5051        struct buffer_head *bh;
5052        loff_t i_size = i_size_read(inode);
5053
5054        if (off > i_size)
5055                return 0;
5056        if (off+len > i_size)
5057                len = i_size-off;
5058        toread = len;
5059        while (toread > 0) {
5060                tocopy = sb->s_blocksize - offset < toread ?
5061                                sb->s_blocksize - offset : toread;
5062                bh = ext4_bread(NULL, inode, blk, 0, &err);
5063                if (err)
5064                        return err;
5065                if (!bh)        /* A hole? */
5066                        memset(data, 0, tocopy);
5067                else
5068                        memcpy(data, bh->b_data+offset, tocopy);
5069                brelse(bh);
5070                offset = 0;
5071                toread -= tocopy;
5072                data += tocopy;
5073                blk++;
5074        }
5075        return len;
5076}
5077
5078/* Write to quotafile (we know the transaction is already started and has
5079 * enough credits) */
5080static ssize_t ext4_quota_write(struct super_block *sb, int type,
5081                                const char *data, size_t len, loff_t off)
5082{
5083        struct inode *inode = sb_dqopt(sb)->files[type];
5084        ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5085        int err = 0;
5086        int offset = off & (sb->s_blocksize - 1);
5087        struct buffer_head *bh;
5088        handle_t *handle = journal_current_handle();
5089
5090        if (EXT4_SB(sb)->s_journal && !handle) {
5091                ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5092                        " cancelled because transaction is not started",
5093                        (unsigned long long)off, (unsigned long long)len);
5094                return -EIO;
5095        }
5096        /*
5097         * Since we account only one data block in transaction credits,
5098         * then it is impossible to cross a block boundary.
5099         */
5100        if (sb->s_blocksize - offset < len) {
5101                ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5102                        " cancelled because not block aligned",
5103                        (unsigned long long)off, (unsigned long long)len);
5104                return -EIO;
5105        }
5106
5107        bh = ext4_bread(handle, inode, blk, 1, &err);
5108        if (!bh)
5109                goto out;
5110        err = ext4_journal_get_write_access(handle, bh);
5111        if (err) {
5112                brelse(bh);
5113                goto out;
5114        }
5115        lock_buffer(bh);
5116        memcpy(bh->b_data+offset