linux/fs/nilfs2/inode.c
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   1/*
   2 * inode.c - NILFS inode operations.
   3 *
   4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 *
  20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21 *
  22 */
  23
  24#include <linux/buffer_head.h>
  25#include <linux/gfp.h>
  26#include <linux/mpage.h>
  27#include <linux/writeback.h>
  28#include <linux/uio.h>
  29#include "nilfs.h"
  30#include "btnode.h"
  31#include "segment.h"
  32#include "page.h"
  33#include "mdt.h"
  34#include "cpfile.h"
  35#include "ifile.h"
  36
  37/**
  38 * struct nilfs_iget_args - arguments used during comparison between inodes
  39 * @ino: inode number
  40 * @cno: checkpoint number
  41 * @root: pointer on NILFS root object (mounted checkpoint)
  42 * @for_gc: inode for GC flag
  43 */
  44struct nilfs_iget_args {
  45        u64 ino;
  46        __u64 cno;
  47        struct nilfs_root *root;
  48        int for_gc;
  49};
  50
  51void nilfs_inode_add_blocks(struct inode *inode, int n)
  52{
  53        struct nilfs_root *root = NILFS_I(inode)->i_root;
  54
  55        inode_add_bytes(inode, (1 << inode->i_blkbits) * n);
  56        if (root)
  57                atomic_add(n, &root->blocks_count);
  58}
  59
  60void nilfs_inode_sub_blocks(struct inode *inode, int n)
  61{
  62        struct nilfs_root *root = NILFS_I(inode)->i_root;
  63
  64        inode_sub_bytes(inode, (1 << inode->i_blkbits) * n);
  65        if (root)
  66                atomic_sub(n, &root->blocks_count);
  67}
  68
  69/**
  70 * nilfs_get_block() - get a file block on the filesystem (callback function)
  71 * @inode - inode struct of the target file
  72 * @blkoff - file block number
  73 * @bh_result - buffer head to be mapped on
  74 * @create - indicate whether allocating the block or not when it has not
  75 *      been allocated yet.
  76 *
  77 * This function does not issue actual read request of the specified data
  78 * block. It is done by VFS.
  79 */
  80int nilfs_get_block(struct inode *inode, sector_t blkoff,
  81                    struct buffer_head *bh_result, int create)
  82{
  83        struct nilfs_inode_info *ii = NILFS_I(inode);
  84        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  85        __u64 blknum = 0;
  86        int err = 0, ret;
  87        unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
  88
  89        down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  90        ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  91        up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  92        if (ret >= 0) { /* found */
  93                map_bh(bh_result, inode->i_sb, blknum);
  94                if (ret > 0)
  95                        bh_result->b_size = (ret << inode->i_blkbits);
  96                goto out;
  97        }
  98        /* data block was not found */
  99        if (ret == -ENOENT && create) {
 100                struct nilfs_transaction_info ti;
 101
 102                bh_result->b_blocknr = 0;
 103                err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
 104                if (unlikely(err))
 105                        goto out;
 106                err = nilfs_bmap_insert(ii->i_bmap, (unsigned long)blkoff,
 107                                        (unsigned long)bh_result);
 108                if (unlikely(err != 0)) {
 109                        if (err == -EEXIST) {
 110                                /*
 111                                 * The get_block() function could be called
 112                                 * from multiple callers for an inode.
 113                                 * However, the page having this block must
 114                                 * be locked in this case.
 115                                 */
 116                                printk(KERN_WARNING
 117                                       "nilfs_get_block: a race condition "
 118                                       "while inserting a data block. "
 119                                       "(inode number=%lu, file block "
 120                                       "offset=%llu)\n",
 121                                       inode->i_ino,
 122                                       (unsigned long long)blkoff);
 123                                err = 0;
 124                        }
 125                        nilfs_transaction_abort(inode->i_sb);
 126                        goto out;
 127                }
 128                nilfs_mark_inode_dirty(inode);
 129                nilfs_transaction_commit(inode->i_sb); /* never fails */
 130                /* Error handling should be detailed */
 131                set_buffer_new(bh_result);
 132                set_buffer_delay(bh_result);
 133                map_bh(bh_result, inode->i_sb, 0); /* dbn must be changed
 134                                                      to proper value */
 135        } else if (ret == -ENOENT) {
 136                /* not found is not error (e.g. hole); must return without
 137                   the mapped state flag. */
 138                ;
 139        } else {
 140                err = ret;
 141        }
 142
 143 out:
 144        return err;
 145}
 146
 147/**
 148 * nilfs_readpage() - implement readpage() method of nilfs_aops {}
 149 * address_space_operations.
 150 * @file - file struct of the file to be read
 151 * @page - the page to be read
 152 */
 153static int nilfs_readpage(struct file *file, struct page *page)
 154{
 155        return mpage_readpage(page, nilfs_get_block);
 156}
 157
 158/**
 159 * nilfs_readpages() - implement readpages() method of nilfs_aops {}
 160 * address_space_operations.
 161 * @file - file struct of the file to be read
 162 * @mapping - address_space struct used for reading multiple pages
 163 * @pages - the pages to be read
 164 * @nr_pages - number of pages to be read
 165 */
 166static int nilfs_readpages(struct file *file, struct address_space *mapping,
 167                           struct list_head *pages, unsigned nr_pages)
 168{
 169        return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
 170}
 171
 172static int nilfs_writepages(struct address_space *mapping,
 173                            struct writeback_control *wbc)
 174{
 175        struct inode *inode = mapping->host;
 176        int err = 0;
 177
 178        if (wbc->sync_mode == WB_SYNC_ALL)
 179                err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 180                                                    wbc->range_start,
 181                                                    wbc->range_end);
 182        return err;
 183}
 184
 185static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 186{
 187        struct inode *inode = page->mapping->host;
 188        int err;
 189
 190        redirty_page_for_writepage(wbc, page);
 191        unlock_page(page);
 192
 193        if (wbc->sync_mode == WB_SYNC_ALL) {
 194                err = nilfs_construct_segment(inode->i_sb);
 195                if (unlikely(err))
 196                        return err;
 197        } else if (wbc->for_reclaim)
 198                nilfs_flush_segment(inode->i_sb, inode->i_ino);
 199
 200        return 0;
 201}
 202
 203static int nilfs_set_page_dirty(struct page *page)
 204{
 205        int ret = __set_page_dirty_buffers(page);
 206
 207        if (ret) {
 208                struct inode *inode = page->mapping->host;
 209                unsigned nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
 210
 211                nilfs_set_file_dirty(inode, nr_dirty);
 212        }
 213        return ret;
 214}
 215
 216static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 217                             loff_t pos, unsigned len, unsigned flags,
 218                             struct page **pagep, void **fsdata)
 219
 220{
 221        struct inode *inode = mapping->host;
 222        int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 223
 224        if (unlikely(err))
 225                return err;
 226
 227        err = block_write_begin(mapping, pos, len, flags, pagep,
 228                                nilfs_get_block);
 229        if (unlikely(err)) {
 230                loff_t isize = mapping->host->i_size;
 231                if (pos + len > isize)
 232                        vmtruncate(mapping->host, isize);
 233
 234                nilfs_transaction_abort(inode->i_sb);
 235        }
 236        return err;
 237}
 238
 239static int nilfs_write_end(struct file *file, struct address_space *mapping,
 240                           loff_t pos, unsigned len, unsigned copied,
 241                           struct page *page, void *fsdata)
 242{
 243        struct inode *inode = mapping->host;
 244        unsigned start = pos & (PAGE_CACHE_SIZE - 1);
 245        unsigned nr_dirty;
 246        int err;
 247
 248        nr_dirty = nilfs_page_count_clean_buffers(page, start,
 249                                                  start + copied);
 250        copied = generic_write_end(file, mapping, pos, len, copied, page,
 251                                   fsdata);
 252        nilfs_set_file_dirty(inode, nr_dirty);
 253        err = nilfs_transaction_commit(inode->i_sb);
 254        return err ? : copied;
 255}
 256
 257static ssize_t
 258nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
 259                loff_t offset, unsigned long nr_segs)
 260{
 261        struct file *file = iocb->ki_filp;
 262        struct inode *inode = file->f_mapping->host;
 263        ssize_t size;
 264
 265        if (rw == WRITE)
 266                return 0;
 267
 268        /* Needs synchronization with the cleaner */
 269        size = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
 270                                  nilfs_get_block);
 271
 272        /*
 273         * In case of error extending write may have instantiated a few
 274         * blocks outside i_size. Trim these off again.
 275         */
 276        if (unlikely((rw & WRITE) && size < 0)) {
 277                loff_t isize = i_size_read(inode);
 278                loff_t end = offset + iov_length(iov, nr_segs);
 279
 280                if (end > isize)
 281                        vmtruncate(inode, isize);
 282        }
 283
 284        return size;
 285}
 286
 287const struct address_space_operations nilfs_aops = {
 288        .writepage              = nilfs_writepage,
 289        .readpage               = nilfs_readpage,
 290        .writepages             = nilfs_writepages,
 291        .set_page_dirty         = nilfs_set_page_dirty,
 292        .readpages              = nilfs_readpages,
 293        .write_begin            = nilfs_write_begin,
 294        .write_end              = nilfs_write_end,
 295        /* .releasepage         = nilfs_releasepage, */
 296        .invalidatepage         = block_invalidatepage,
 297        .direct_IO              = nilfs_direct_IO,
 298        .is_partially_uptodate  = block_is_partially_uptodate,
 299};
 300
 301struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 302{
 303        struct super_block *sb = dir->i_sb;
 304        struct the_nilfs *nilfs = sb->s_fs_info;
 305        struct inode *inode;
 306        struct nilfs_inode_info *ii;
 307        struct nilfs_root *root;
 308        int err = -ENOMEM;
 309        ino_t ino;
 310
 311        inode = new_inode(sb);
 312        if (unlikely(!inode))
 313                goto failed;
 314
 315        mapping_set_gfp_mask(inode->i_mapping,
 316                             mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 317
 318        root = NILFS_I(dir)->i_root;
 319        ii = NILFS_I(inode);
 320        ii->i_state = 1 << NILFS_I_NEW;
 321        ii->i_root = root;
 322
 323        err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
 324        if (unlikely(err))
 325                goto failed_ifile_create_inode;
 326        /* reference count of i_bh inherits from nilfs_mdt_read_block() */
 327
 328        atomic_inc(&root->inodes_count);
 329        inode_init_owner(inode, dir, mode);
 330        inode->i_ino = ino;
 331        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 332
 333        if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 334                err = nilfs_bmap_read(ii->i_bmap, NULL);
 335                if (err < 0)
 336                        goto failed_bmap;
 337
 338                set_bit(NILFS_I_BMAP, &ii->i_state);
 339                /* No lock is needed; iget() ensures it. */
 340        }
 341
 342        ii->i_flags = nilfs_mask_flags(
 343                mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 344
 345        /* ii->i_file_acl = 0; */
 346        /* ii->i_dir_acl = 0; */
 347        ii->i_dir_start_lookup = 0;
 348        nilfs_set_inode_flags(inode);
 349        spin_lock(&nilfs->ns_next_gen_lock);
 350        inode->i_generation = nilfs->ns_next_generation++;
 351        spin_unlock(&nilfs->ns_next_gen_lock);
 352        insert_inode_hash(inode);
 353
 354        err = nilfs_init_acl(inode, dir);
 355        if (unlikely(err))
 356                goto failed_acl; /* never occur. When supporting
 357                                    nilfs_init_acl(), proper cancellation of
 358                                    above jobs should be considered */
 359
 360        return inode;
 361
 362 failed_acl:
 363 failed_bmap:
 364        clear_nlink(inode);
 365        iput(inode);  /* raw_inode will be deleted through
 366                         generic_delete_inode() */
 367        goto failed;
 368
 369 failed_ifile_create_inode:
 370        make_bad_inode(inode);
 371        iput(inode);  /* if i_nlink == 1, generic_forget_inode() will be
 372                         called */
 373 failed:
 374        return ERR_PTR(err);
 375}
 376
 377void nilfs_set_inode_flags(struct inode *inode)
 378{
 379        unsigned int flags = NILFS_I(inode)->i_flags;
 380
 381        inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
 382                            S_DIRSYNC);
 383        if (flags & FS_SYNC_FL)
 384                inode->i_flags |= S_SYNC;
 385        if (flags & FS_APPEND_FL)
 386                inode->i_flags |= S_APPEND;
 387        if (flags & FS_IMMUTABLE_FL)
 388                inode->i_flags |= S_IMMUTABLE;
 389        if (flags & FS_NOATIME_FL)
 390                inode->i_flags |= S_NOATIME;
 391        if (flags & FS_DIRSYNC_FL)
 392                inode->i_flags |= S_DIRSYNC;
 393        mapping_set_gfp_mask(inode->i_mapping,
 394                             mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 395}
 396
 397int nilfs_read_inode_common(struct inode *inode,
 398                            struct nilfs_inode *raw_inode)
 399{
 400        struct nilfs_inode_info *ii = NILFS_I(inode);
 401        int err;
 402
 403        inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 404        inode->i_uid = (uid_t)le32_to_cpu(raw_inode->i_uid);
 405        inode->i_gid = (gid_t)le32_to_cpu(raw_inode->i_gid);
 406        set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 407        inode->i_size = le64_to_cpu(raw_inode->i_size);
 408        inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 409        inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 410        inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 411        inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 412        inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 413        inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 414        if (inode->i_nlink == 0 && inode->i_mode == 0)
 415                return -EINVAL; /* this inode is deleted */
 416
 417        inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 418        ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 419#if 0
 420        ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 421        ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 422                0 : le32_to_cpu(raw_inode->i_dir_acl);
 423#endif
 424        ii->i_dir_start_lookup = 0;
 425        inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 426
 427        if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 428            S_ISLNK(inode->i_mode)) {
 429                err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 430                if (err < 0)
 431                        return err;
 432                set_bit(NILFS_I_BMAP, &ii->i_state);
 433                /* No lock is needed; iget() ensures it. */
 434        }
 435        return 0;
 436}
 437
 438static int __nilfs_read_inode(struct super_block *sb,
 439                              struct nilfs_root *root, unsigned long ino,
 440                              struct inode *inode)
 441{
 442        struct the_nilfs *nilfs = sb->s_fs_info;
 443        struct buffer_head *bh;
 444        struct nilfs_inode *raw_inode;
 445        int err;
 446
 447        down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 448        err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 449        if (unlikely(err))
 450                goto bad_inode;
 451
 452        raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 453
 454        err = nilfs_read_inode_common(inode, raw_inode);
 455        if (err)
 456                goto failed_unmap;
 457
 458        if (S_ISREG(inode->i_mode)) {
 459                inode->i_op = &nilfs_file_inode_operations;
 460                inode->i_fop = &nilfs_file_operations;
 461                inode->i_mapping->a_ops = &nilfs_aops;
 462        } else if (S_ISDIR(inode->i_mode)) {
 463                inode->i_op = &nilfs_dir_inode_operations;
 464                inode->i_fop = &nilfs_dir_operations;
 465                inode->i_mapping->a_ops = &nilfs_aops;
 466        } else if (S_ISLNK(inode->i_mode)) {
 467                inode->i_op = &nilfs_symlink_inode_operations;
 468                inode->i_mapping->a_ops = &nilfs_aops;
 469        } else {
 470                inode->i_op = &nilfs_special_inode_operations;
 471                init_special_inode(
 472                        inode, inode->i_mode,
 473                        huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 474        }
 475        nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 476        brelse(bh);
 477        up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 478        nilfs_set_inode_flags(inode);
 479        return 0;
 480
 481 failed_unmap:
 482        nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 483        brelse(bh);
 484
 485 bad_inode:
 486        up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 487        return err;
 488}
 489
 490static int nilfs_iget_test(struct inode *inode, void *opaque)
 491{
 492        struct nilfs_iget_args *args = opaque;
 493        struct nilfs_inode_info *ii;
 494
 495        if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 496                return 0;
 497
 498        ii = NILFS_I(inode);
 499        if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 500                return !args->for_gc;
 501
 502        return args->for_gc && args->cno == ii->i_cno;
 503}
 504
 505static int nilfs_iget_set(struct inode *inode, void *opaque)
 506{
 507        struct nilfs_iget_args *args = opaque;
 508
 509        inode->i_ino = args->ino;
 510        if (args->for_gc) {
 511                NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
 512                NILFS_I(inode)->i_cno = args->cno;
 513                NILFS_I(inode)->i_root = NULL;
 514        } else {
 515                if (args->root && args->ino == NILFS_ROOT_INO)
 516                        nilfs_get_root(args->root);
 517                NILFS_I(inode)->i_root = args->root;
 518        }
 519        return 0;
 520}
 521
 522struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 523                            unsigned long ino)
 524{
 525        struct nilfs_iget_args args = {
 526                .ino = ino, .root = root, .cno = 0, .for_gc = 0
 527        };
 528
 529        return ilookup5(sb, ino, nilfs_iget_test, &args);
 530}
 531
 532struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 533                                unsigned long ino)
 534{
 535        struct nilfs_iget_args args = {
 536                .ino = ino, .root = root, .cno = 0, .for_gc = 0
 537        };
 538
 539        return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 540}
 541
 542struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 543                         unsigned long ino)
 544{
 545        struct inode *inode;
 546        int err;
 547
 548        inode = nilfs_iget_locked(sb, root, ino);
 549        if (unlikely(!inode))
 550                return ERR_PTR(-ENOMEM);
 551        if (!(inode->i_state & I_NEW))
 552                return inode;
 553
 554        err = __nilfs_read_inode(sb, root, ino, inode);
 555        if (unlikely(err)) {
 556                iget_failed(inode);
 557                return ERR_PTR(err);
 558        }
 559        unlock_new_inode(inode);
 560        return inode;
 561}
 562
 563struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 564                                __u64 cno)
 565{
 566        struct nilfs_iget_args args = {
 567                .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
 568        };
 569        struct inode *inode;
 570        int err;
 571
 572        inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 573        if (unlikely(!inode))
 574                return ERR_PTR(-ENOMEM);
 575        if (!(inode->i_state & I_NEW))
 576                return inode;
 577
 578        err = nilfs_init_gcinode(inode);
 579        if (unlikely(err)) {
 580                iget_failed(inode);
 581                return ERR_PTR(err);
 582        }
 583        unlock_new_inode(inode);
 584        return inode;
 585}
 586
 587void nilfs_write_inode_common(struct inode *inode,
 588                              struct nilfs_inode *raw_inode, int has_bmap)
 589{
 590        struct nilfs_inode_info *ii = NILFS_I(inode);
 591
 592        raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 593        raw_inode->i_uid = cpu_to_le32(inode->i_uid);
 594        raw_inode->i_gid = cpu_to_le32(inode->i_gid);
 595        raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 596        raw_inode->i_size = cpu_to_le64(inode->i_size);
 597        raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 598        raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 599        raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 600        raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 601        raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 602
 603        raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 604        raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 605
 606        if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 607                struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 608
 609                /* zero-fill unused portion in the case of super root block */
 610                raw_inode->i_xattr = 0;
 611                raw_inode->i_pad = 0;
 612                memset((void *)raw_inode + sizeof(*raw_inode), 0,
 613                       nilfs->ns_inode_size - sizeof(*raw_inode));
 614        }
 615
 616        if (has_bmap)
 617                nilfs_bmap_write(ii->i_bmap, raw_inode);
 618        else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 619                raw_inode->i_device_code =
 620                        cpu_to_le64(huge_encode_dev(inode->i_rdev));
 621        /* When extending inode, nilfs->ns_inode_size should be checked
 622           for substitutions of appended fields */
 623}
 624
 625void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh)
 626{
 627        ino_t ino = inode->i_ino;
 628        struct nilfs_inode_info *ii = NILFS_I(inode);
 629        struct inode *ifile = ii->i_root->ifile;
 630        struct nilfs_inode *raw_inode;
 631
 632        raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 633
 634        if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 635                memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 636        set_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
 637
 638        nilfs_write_inode_common(inode, raw_inode, 0);
 639                /* XXX: call with has_bmap = 0 is a workaround to avoid
 640                   deadlock of bmap. This delays update of i_bmap to just
 641                   before writing */
 642        nilfs_ifile_unmap_inode(ifile, ino, ibh);
 643}
 644
 645#define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
 646
 647static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 648                                unsigned long from)
 649{
 650        unsigned long b;
 651        int ret;
 652
 653        if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 654                return;
 655repeat:
 656        ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 657        if (ret == -ENOENT)
 658                return;
 659        else if (ret < 0)
 660                goto failed;
 661
 662        if (b < from)
 663                return;
 664
 665        b -= min_t(unsigned long, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 666        ret = nilfs_bmap_truncate(ii->i_bmap, b);
 667        nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 668        if (!ret || (ret == -ENOMEM &&
 669                     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 670                goto repeat;
 671
 672failed:
 673        nilfs_warning(ii->vfs_inode.i_sb, __func__,
 674                      "failed to truncate bmap (ino=%lu, err=%d)",
 675                      ii->vfs_inode.i_ino, ret);
 676}
 677
 678void nilfs_truncate(struct inode *inode)
 679{
 680        unsigned long blkoff;
 681        unsigned int blocksize;
 682        struct nilfs_transaction_info ti;
 683        struct super_block *sb = inode->i_sb;
 684        struct nilfs_inode_info *ii = NILFS_I(inode);
 685
 686        if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 687                return;
 688        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 689                return;
 690
 691        blocksize = sb->s_blocksize;
 692        blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 693        nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 694
 695        block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 696
 697        nilfs_truncate_bmap(ii, blkoff);
 698
 699        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 700        if (IS_SYNC(inode))
 701                nilfs_set_transaction_flag(NILFS_TI_SYNC);
 702
 703        nilfs_mark_inode_dirty(inode);
 704        nilfs_set_file_dirty(inode, 0);
 705        nilfs_transaction_commit(sb);
 706        /* May construct a logical segment and may fail in sync mode.
 707           But truncate has no return value. */
 708}
 709
 710static void nilfs_clear_inode(struct inode *inode)
 711{
 712        struct nilfs_inode_info *ii = NILFS_I(inode);
 713        struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 714
 715        /*
 716         * Free resources allocated in nilfs_read_inode(), here.
 717         */
 718        BUG_ON(!list_empty(&ii->i_dirty));
 719        brelse(ii->i_bh);
 720        ii->i_bh = NULL;
 721
 722        if (mdi && mdi->mi_palloc_cache)
 723                nilfs_palloc_destroy_cache(inode);
 724
 725        if (test_bit(NILFS_I_BMAP, &ii->i_state))
 726                nilfs_bmap_clear(ii->i_bmap);
 727
 728        nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 729
 730        if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 731                nilfs_put_root(ii->i_root);
 732}
 733
 734void nilfs_evict_inode(struct inode *inode)
 735{
 736        struct nilfs_transaction_info ti;
 737        struct super_block *sb = inode->i_sb;
 738        struct nilfs_inode_info *ii = NILFS_I(inode);
 739        int ret;
 740
 741        if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 742                if (inode->i_data.nrpages)
 743                        truncate_inode_pages(&inode->i_data, 0);
 744                clear_inode(inode);
 745                nilfs_clear_inode(inode);
 746                return;
 747        }
 748        nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 749
 750        if (inode->i_data.nrpages)
 751                truncate_inode_pages(&inode->i_data, 0);
 752
 753        /* TODO: some of the following operations may fail.  */
 754        nilfs_truncate_bmap(ii, 0);
 755        nilfs_mark_inode_dirty(inode);
 756        clear_inode(inode);
 757
 758        ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 759        if (!ret)
 760                atomic_dec(&ii->i_root->inodes_count);
 761
 762        nilfs_clear_inode(inode);
 763
 764        if (IS_SYNC(inode))
 765                nilfs_set_transaction_flag(NILFS_TI_SYNC);
 766        nilfs_transaction_commit(sb);
 767        /* May construct a logical segment and may fail in sync mode.
 768           But delete_inode has no return value. */
 769}
 770
 771int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
 772{
 773        struct nilfs_transaction_info ti;
 774        struct inode *inode = dentry->d_inode;
 775        struct super_block *sb = inode->i_sb;
 776        int err;
 777
 778        err = inode_change_ok(inode, iattr);
 779        if (err)
 780                return err;
 781
 782        err = nilfs_transaction_begin(sb, &ti, 0);
 783        if (unlikely(err))
 784                return err;
 785
 786        if ((iattr->ia_valid & ATTR_SIZE) &&
 787            iattr->ia_size != i_size_read(inode)) {
 788                inode_dio_wait(inode);
 789
 790                err = vmtruncate(inode, iattr->ia_size);
 791                if (unlikely(err))
 792                        goto out_err;
 793        }
 794
 795        setattr_copy(inode, iattr);
 796        mark_inode_dirty(inode);
 797
 798        if (iattr->ia_valid & ATTR_MODE) {
 799                err = nilfs_acl_chmod(inode);
 800                if (unlikely(err))
 801                        goto out_err;
 802        }
 803
 804        return nilfs_transaction_commit(sb);
 805
 806out_err:
 807        nilfs_transaction_abort(sb);
 808        return err;
 809}
 810
 811int nilfs_permission(struct inode *inode, int mask)
 812{
 813        struct nilfs_root *root = NILFS_I(inode)->i_root;
 814        if ((mask & MAY_WRITE) && root &&
 815            root->cno != NILFS_CPTREE_CURRENT_CNO)
 816                return -EROFS; /* snapshot is not writable */
 817
 818        return generic_permission(inode, mask);
 819}
 820
 821int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
 822{
 823        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 824        struct nilfs_inode_info *ii = NILFS_I(inode);
 825        int err;
 826
 827        spin_lock(&nilfs->ns_inode_lock);
 828        if (ii->i_bh == NULL) {
 829                spin_unlock(&nilfs->ns_inode_lock);
 830                err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
 831                                                  inode->i_ino, pbh);
 832                if (unlikely(err))
 833                        return err;
 834                spin_lock(&nilfs->ns_inode_lock);
 835                if (ii->i_bh == NULL)
 836                        ii->i_bh = *pbh;
 837                else {
 838                        brelse(*pbh);
 839                        *pbh = ii->i_bh;
 840                }
 841        } else
 842                *pbh = ii->i_bh;
 843
 844        get_bh(*pbh);
 845        spin_unlock(&nilfs->ns_inode_lock);
 846        return 0;
 847}
 848
 849int nilfs_inode_dirty(struct inode *inode)
 850{
 851        struct nilfs_inode_info *ii = NILFS_I(inode);
 852        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 853        int ret = 0;
 854
 855        if (!list_empty(&ii->i_dirty)) {
 856                spin_lock(&nilfs->ns_inode_lock);
 857                ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
 858                        test_bit(NILFS_I_BUSY, &ii->i_state);
 859                spin_unlock(&nilfs->ns_inode_lock);
 860        }
 861        return ret;
 862}
 863
 864int nilfs_set_file_dirty(struct inode *inode, unsigned nr_dirty)
 865{
 866        struct nilfs_inode_info *ii = NILFS_I(inode);
 867        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 868
 869        atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
 870
 871        if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
 872                return 0;
 873
 874        spin_lock(&nilfs->ns_inode_lock);
 875        if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
 876            !test_bit(NILFS_I_BUSY, &ii->i_state)) {
 877                /* Because this routine may race with nilfs_dispose_list(),
 878                   we have to check NILFS_I_QUEUED here, too. */
 879                if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
 880                        /* This will happen when somebody is freeing
 881                           this inode. */
 882                        nilfs_warning(inode->i_sb, __func__,
 883                                      "cannot get inode (ino=%lu)\n",
 884                                      inode->i_ino);
 885                        spin_unlock(&nilfs->ns_inode_lock);
 886                        return -EINVAL; /* NILFS_I_DIRTY may remain for
 887                                           freeing inode */
 888                }
 889                list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
 890                set_bit(NILFS_I_QUEUED, &ii->i_state);
 891        }
 892        spin_unlock(&nilfs->ns_inode_lock);
 893        return 0;
 894}
 895
 896int nilfs_mark_inode_dirty(struct inode *inode)
 897{
 898        struct buffer_head *ibh;
 899        int err;
 900
 901        err = nilfs_load_inode_block(inode, &ibh);
 902        if (unlikely(err)) {
 903                nilfs_warning(inode->i_sb, __func__,
 904                              "failed to reget inode block.\n");
 905                return err;
 906        }
 907        nilfs_update_inode(inode, ibh);
 908        mark_buffer_dirty(ibh);
 909        nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
 910        brelse(ibh);
 911        return 0;
 912}
 913
 914/**
 915 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
 916 * @inode: inode of the file to be registered.
 917 *
 918 * nilfs_dirty_inode() loads a inode block containing the specified
 919 * @inode and copies data from a nilfs_inode to a corresponding inode
 920 * entry in the inode block. This operation is excluded from the segment
 921 * construction. This function can be called both as a single operation
 922 * and as a part of indivisible file operations.
 923 */
 924void nilfs_dirty_inode(struct inode *inode, int flags)
 925{
 926        struct nilfs_transaction_info ti;
 927        struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 928
 929        if (is_bad_inode(inode)) {
 930                nilfs_warning(inode->i_sb, __func__,
 931                              "tried to mark bad_inode dirty. ignored.\n");
 932                dump_stack();
 933                return;
 934        }
 935        if (mdi) {
 936                nilfs_mdt_mark_dirty(inode);
 937                return;
 938        }
 939        nilfs_transaction_begin(inode->i_sb, &ti, 0);
 940        nilfs_mark_inode_dirty(inode);
 941        nilfs_transaction_commit(inode->i_sb); /* never fails */
 942}
 943
 944int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 945                 __u64 start, __u64 len)
 946{
 947        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 948        __u64 logical = 0, phys = 0, size = 0;
 949        __u32 flags = 0;
 950        loff_t isize;
 951        sector_t blkoff, end_blkoff;
 952        sector_t delalloc_blkoff;
 953        unsigned long delalloc_blklen;
 954        unsigned int blkbits = inode->i_blkbits;
 955        int ret, n;
 956
 957        ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 958        if (ret)
 959                return ret;
 960
 961        mutex_lock(&inode->i_mutex);
 962
 963        isize = i_size_read(inode);
 964
 965        blkoff = start >> blkbits;
 966        end_blkoff = (start + len - 1) >> blkbits;
 967
 968        delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
 969                                                        &delalloc_blkoff);
 970
 971        do {
 972                __u64 blkphy;
 973                unsigned int maxblocks;
 974
 975                if (delalloc_blklen && blkoff == delalloc_blkoff) {
 976                        if (size) {
 977                                /* End of the current extent */
 978                                ret = fiemap_fill_next_extent(
 979                                        fieinfo, logical, phys, size, flags);
 980                                if (ret)
 981                                        break;
 982                        }
 983                        if (blkoff > end_blkoff)
 984                                break;
 985
 986                        flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
 987                        logical = blkoff << blkbits;
 988                        phys = 0;
 989                        size = delalloc_blklen << blkbits;
 990
 991                        blkoff = delalloc_blkoff + delalloc_blklen;
 992                        delalloc_blklen = nilfs_find_uncommitted_extent(
 993                                inode, blkoff, &delalloc_blkoff);
 994                        continue;
 995                }
 996
 997                /*
 998                 * Limit the number of blocks that we look up so as
 999                 * not to get into the next delayed allocation extent.
1000                 */
1001                maxblocks = INT_MAX;
1002                if (delalloc_blklen)
1003                        maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1004                                          maxblocks);
1005                blkphy = 0;
1006
1007                down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1008                n = nilfs_bmap_lookup_contig(
1009                        NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1010                up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1011
1012                if (n < 0) {
1013                        int past_eof;
1014
1015                        if (unlikely(n != -ENOENT))
1016                                break; /* error */
1017
1018                        /* HOLE */
1019                        blkoff++;
1020                        past_eof = ((blkoff << blkbits) >= isize);
1021
1022                        if (size) {
1023                                /* End of the current extent */
1024
1025                                if (past_eof)
1026                                        flags |= FIEMAP_EXTENT_LAST;
1027
1028                                ret = fiemap_fill_next_extent(
1029                                        fieinfo, logical, phys, size, flags);
1030                                if (ret)
1031                                        break;
1032                                size = 0;
1033                        }
1034                        if (blkoff > end_blkoff || past_eof)
1035                                break;
1036                } else {
1037                        if (size) {
1038                                if (phys && blkphy << blkbits == phys + size) {
1039                                        /* The current extent goes on */
1040                                        size += n << blkbits;
1041                                } else {
1042                                        /* Terminate the current extent */
1043                                        ret = fiemap_fill_next_extent(
1044                                                fieinfo, logical, phys, size,
1045                                                flags);
1046                                        if (ret || blkoff > end_blkoff)
1047                                                break;
1048
1049                                        /* Start another extent */
1050                                        flags = FIEMAP_EXTENT_MERGED;
1051                                        logical = blkoff << blkbits;
1052                                        phys = blkphy << blkbits;
1053                                        size = n << blkbits;
1054                                }
1055                        } else {
1056                                /* Start a new extent */
1057                                flags = FIEMAP_EXTENT_MERGED;
1058                                logical = blkoff << blkbits;
1059                                phys = blkphy << blkbits;
1060                                size = n << blkbits;
1061                        }
1062                        blkoff += n;
1063                }
1064                cond_resched();
1065        } while (true);
1066
1067        /* If ret is 1 then we just hit the end of the extent array */
1068        if (ret == 1)
1069                ret = 0;
1070
1071        mutex_unlock(&inode->i_mutex);
1072        return ret;
1073}
1074
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