kernel/fs/nilfs2/inode.c

   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/pagemap.h>
  28 #include <linux/writeback.h>
  29 #include <linux/uio.h>
  30 #include "nilfs.h"
  31 #include "btnode.h"
  32 #include "segment.h"
  33 #include "page.h"
  34 #include "mdt.h"
  35 #include "cpfile.h"
  36 #include "ifile.h"
  37
  38 /**
  39  * struct nilfs_iget_args - arguments used during comparison between inodes
  40  * @ino: inode number
  41  * @cno: checkpoint number
  42  * @root: pointer on NILFS root object (mounted checkpoint)
  43  * @for_gc: inode for GC flag
  44  */
  45 struct nilfs_iget_args {
  46         u64 ino;
  47         __u64 cno;
  48         struct nilfs_root *root;
  49         int for_gc;
  50 };
  51
  52 static int nilfs_iget_test(struct inode *inode, void *opaque);
  53
  54 void nilfs_inode_add_blocks(struct inode *inode, int n)
  55 {
  56         struct nilfs_root *root = NILFS_I(inode)->i_root;
  57
  58         inode_add_bytes(inode, (1 << inode->i_blkbits) * n);
  59         if (root)
  60                 atomic64_add(n, &root->blocks_count);
  61 }
  62
  63 void nilfs_inode_sub_blocks(struct inode *inode, int n)
  64 {
  65         struct nilfs_root *root = NILFS_I(inode)->i_root;
  66
  67         inode_sub_bytes(inode, (1 << inode->i_blkbits) * n);
  68         if (root)
  69                 atomic64_sub(n, &root->blocks_count);
  70 }
  71
  72 /**
  73  * nilfs_get_block() - get a file block on the filesystem (callback function)
  74  * @inode - inode struct of the target file
  75  * @blkoff - file block number
  76  * @bh_result - buffer head to be mapped on
  77  * @create - indicate whether allocating the block or not when it has not
  78  *      been allocated yet.
  79  *
  80  * This function does not issue actual read request of the specified data
  81  * block. It is done by VFS.
  82  */
  83 int nilfs_get_block(struct inode *inode, sector_t blkoff,
  84                     struct buffer_head *bh_result, int create)
  85 {
  86         struct nilfs_inode_info *ii = NILFS_I(inode);
  87         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  88         __u64 blknum = 0;
  89         int err = 0, ret;
  90         unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
  91
  92         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  93         ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  94         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  95         if (ret >= 0) { /* found */
  96                 map_bh(bh_result, inode->i_sb, blknum);
  97                 if (ret > 0)
  98                         bh_result->b_size = (ret << inode->i_blkbits);
  99                 goto out;
 100         }
 101         /* data block was not found */
 102         if (ret == -ENOENT && create) {
 103                 struct nilfs_transaction_info ti;
 104
 105                 bh_result->b_blocknr = 0;
 106                 err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
 107                 if (unlikely(err))
 108                         goto out;
 109                 err = nilfs_bmap_insert(ii->i_bmap, blkoff,
 110                                         (unsigned long)bh_result);
 111                 if (unlikely(err != 0)) {
 112                         if (err == -EEXIST) {
 113                                 /*
 114                                  * The get_block() function could be called
 115                                  * from multiple callers for an inode.
 116                                  * However, the page having this block must
 117                                  * be locked in this case.
 118                                  */
 119                                 printk(KERN_WARNING
 120                                        "nilfs_get_block: a race condition "
 121                                        "while inserting a data block. "
 122                                        "(inode number=%lu, file block "
 123                                        "offset=%llu)\n",
 124                                        inode->i_ino,
 125                                        (unsigned long long)blkoff);
 126                                 err = 0;
 127                         }
 128                         nilfs_transaction_abort(inode->i_sb);
 129                         goto out;
 130                 }
 131                 nilfs_mark_inode_dirty_sync(inode);
 132                 nilfs_transaction_commit(inode->i_sb); /* never fails */
 133                 /* Error handling should be detailed */
 134                 set_buffer_new(bh_result);
 135                 set_buffer_delay(bh_result);
 136                 map_bh(bh_result, inode->i_sb, 0); /* dbn must be changed
 137                                                       to proper value */
 138         } else if (ret == -ENOENT) {
 139                 /* not found is not error (e.g. hole); must return without
 140                    the mapped state flag. */
 141                 ;
 142         } else {
 143                 err = ret;
 144         }
 145
 146  out:
 147         return err;
 148 }
 149
 150 /**
 151  * nilfs_readpage() - implement readpage() method of nilfs_aops {}
 152  * address_space_operations.
 153  * @file - file struct of the file to be read
 154  * @page - the page to be read
 155  */
 156 static int nilfs_readpage(struct file *file, struct page *page)
 157 {
 158         return mpage_readpage(page, nilfs_get_block);
 159 }
 160
 161 /**
 162  * nilfs_readpages() - implement readpages() method of nilfs_aops {}
 163  * address_space_operations.
 164  * @file - file struct of the file to be read
 165  * @mapping - address_space struct used for reading multiple pages
 166  * @pages - the pages to be read
 167  * @nr_pages - number of pages to be read
 168  */
 169 static int nilfs_readpages(struct file *file, struct address_space *mapping,
 170                            struct list_head *pages, unsigned nr_pages)
 171 {
 172         return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
 173 }
 174
 175 static int nilfs_writepages(struct address_space *mapping,
 176                             struct writeback_control *wbc)
 177 {
 178         struct inode *inode = mapping->host;
 179         int err = 0;
 180
 181         if (inode->i_sb->s_flags & MS_RDONLY) {
 182                 nilfs_clear_dirty_pages(mapping, false);
 183                 return -EROFS;
 184         }
 185
 186         if (wbc->sync_mode == WB_SYNC_ALL)
 187                 err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 188                                                     wbc->range_start,
 189                                                     wbc->range_end);
 190         return err;
 191 }
 192
 193 static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 194 {
 195         struct inode *inode = page->mapping->host;
 196         int err;
 197
 198         if (inode->i_sb->s_flags & MS_RDONLY) {
 199                 /*
 200                  * It means that filesystem was remounted in read-only
 201                  * mode because of error or metadata corruption. But we
 202                  * have dirty pages that try to be flushed in background.
 203                  * So, here we simply discard this dirty page.
 204                  */
 205                 nilfs_clear_dirty_page(page, false);
 206                 unlock_page(page);
 207                 return -EROFS;
 208         }
 209
 210         redirty_page_for_writepage(wbc, page);
 211         unlock_page(page);
 212
 213         if (wbc->sync_mode == WB_SYNC_ALL) {
 214                 err = nilfs_construct_segment(inode->i_sb);
 215                 if (unlikely(err))
 216                         return err;
 217         } else if (wbc->for_reclaim)
 218                 nilfs_flush_segment(inode->i_sb, inode->i_ino);
 219
 220         return 0;
 221 }
 222
 223 static int nilfs_set_page_dirty(struct page *page)
 224 {
 225         struct inode *inode = page->mapping->host;
 226         int ret = __set_page_dirty_nobuffers(page);
 227
 228         if (page_has_buffers(page)) {
 229                 unsigned nr_dirty = 0;
 230                 struct buffer_head *bh, *head;
 231
 232                 /*
 233                  * This page is locked by callers, and no other thread
 234                  * concurrently marks its buffers dirty since they are
 235                  * only dirtied through routines in fs/buffer.c in
 236                  * which call sites of mark_buffer_dirty are protected
 237                  * by page lock.
 238                  */
 239                 bh = head = page_buffers(page);
 240                 do {
 241                         /* Do not mark hole blocks dirty */
 242                         if (buffer_dirty(bh) || !buffer_mapped(bh))
 243                                 continue;
 244
 245                         set_buffer_dirty(bh);
 246                         nr_dirty++;
 247                 } while (bh = bh->b_this_page, bh != head);
 248
 249                 if (nr_dirty)
 250                         nilfs_set_file_dirty(inode, nr_dirty);
 251         } else if (ret) {
 252                 unsigned nr_dirty = 1 << (PAGE_CACHE_SHIFT - inode->i_blkbits);
 253
 254                 nilfs_set_file_dirty(inode, nr_dirty);
 255         }
 256         return ret;
 257 }
 258
 259 void nilfs_write_failed(struct address_space *mapping, loff_t to)
 260 {
 261         struct inode *inode = mapping->host;
 262
 263         if (to > inode->i_size) {
 264                 truncate_pagecache(inode, inode->i_size);
 265                 nilfs_truncate(inode);
 266         }
 267 }
 268
 269 static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 270                              loff_t pos, unsigned len, unsigned flags,
 271                              struct page **pagep, void **fsdata)
 272
 273 {
 274         struct inode *inode = mapping->host;
 275         int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 276
 277         if (unlikely(err))
 278                 return err;
 279
 280         err = block_write_begin(mapping, pos, len, flags, pagep,
 281                                 nilfs_get_block);
 282         if (unlikely(err)) {
 283                 nilfs_write_failed(mapping, pos + len);
 284                 nilfs_transaction_abort(inode->i_sb);
 285         }
 286         return err;
 287 }
 288
 289 static int nilfs_write_end(struct file *file, struct address_space *mapping,
 290                            loff_t pos, unsigned len, unsigned copied,
 291                            struct page *page, void *fsdata)
 292 {
 293         struct inode *inode = mapping->host;
 294         unsigned start = pos & (PAGE_CACHE_SIZE - 1);
 295         unsigned nr_dirty;
 296         int err;
 297
 298         nr_dirty = nilfs_page_count_clean_buffers(page, start,
 299                                                   start + copied);
 300         copied = generic_write_end(file, mapping, pos, len, copied, page,
 301                                    fsdata);
 302         nilfs_set_file_dirty(inode, nr_dirty);
 303         err = nilfs_transaction_commit(inode->i_sb);
 304         return err ? : copied;
 305 }
 306
 307 static ssize_t
 308 nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
 309 {
 310         struct file *file = iocb->ki_filp;
 311         struct address_space *mapping = file->f_mapping;
 312         struct inode *inode = file->f_mapping->host;
 313         size_t count = iov_iter_count(iter);
 314         ssize_t size;
 315
 316         if (iov_iter_rw(iter) == WRITE)
 317                 return 0;
 318
 319         /* Needs synchronization with the cleaner */
 320         size = blockdev_direct_IO(iocb, inode, iter, offset, nilfs_get_block);
 321
 322         /*
 323          * In case of error extending write may have instantiated a few
 324          * blocks outside i_size. Trim these off again.
 325          */
 326         if (unlikely(iov_iter_rw(iter) == WRITE && size < 0)) {
 327                 loff_t isize = i_size_read(inode);
 328                 loff_t end = offset + count;
 329
 330                 if (end > isize)
 331                         nilfs_write_failed(mapping, end);
 332         }
 333
 334         return size;
 335 }
 336
 337 const struct address_space_operations nilfs_aops = {
 338         .writepage              = nilfs_writepage,
 339         .readpage               = nilfs_readpage,
 340         .writepages             = nilfs_writepages,
 341         .set_page_dirty         = nilfs_set_page_dirty,
 342         .readpages              = nilfs_readpages,
 343         .write_begin            = nilfs_write_begin,
 344         .write_end              = nilfs_write_end,
 345         /* .releasepage         = nilfs_releasepage, */
 346         .invalidatepage         = block_invalidatepage,
 347         .direct_IO              = nilfs_direct_IO,
 348         .is_partially_uptodate  = block_is_partially_uptodate,
 349 };
 350
 351 static int nilfs_insert_inode_locked(struct inode *inode,
 352                                      struct nilfs_root *root,
 353                                      unsigned long ino)
 354 {
 355         struct nilfs_iget_args args = {
 356                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
 357         };
 358
 359         return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
 360 }
 361
 362 struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 363 {
 364         struct super_block *sb = dir->i_sb;
 365         struct the_nilfs *nilfs = sb->s_fs_info;
 366         struct inode *inode;
 367         struct nilfs_inode_info *ii;
 368         struct nilfs_root *root;
 369         int err = -ENOMEM;
 370         ino_t ino;
 371
 372         inode = new_inode(sb);
 373         if (unlikely(!inode))
 374                 goto failed;
 375
 376         mapping_set_gfp_mask(inode->i_mapping,
 377                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 378
 379         root = NILFS_I(dir)->i_root;
 380         ii = NILFS_I(inode);
 381         ii->i_state = 1 << NILFS_I_NEW;
 382         ii->i_root = root;
 383
 384         err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
 385         if (unlikely(err))
 386                 goto failed_ifile_create_inode;
 387         /* reference count of i_bh inherits from nilfs_mdt_read_block() */
 388
 389         atomic64_inc(&root->inodes_count);
 390         inode_init_owner(inode, dir, mode);
 391         inode->i_ino = ino;
 392         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 393
 394         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 395                 err = nilfs_bmap_read(ii->i_bmap, NULL);
 396                 if (err < 0)
 397                         goto failed_after_creation;
 398
 399                 set_bit(NILFS_I_BMAP, &ii->i_state);
 400                 /* No lock is needed; iget() ensures it. */
 401         }
 402
 403         ii->i_flags = nilfs_mask_flags(
 404                 mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 405
 406         /* ii->i_file_acl = 0; */
 407         /* ii->i_dir_acl = 0; */
 408         ii->i_dir_start_lookup = 0;
 409         nilfs_set_inode_flags(inode);
 410         spin_lock(&nilfs->ns_next_gen_lock);
 411         inode->i_generation = nilfs->ns_next_generation++;
 412         spin_unlock(&nilfs->ns_next_gen_lock);
 413         if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
 414                 err = -EIO;
 415                 goto failed_after_creation;
 416         }
 417
 418         err = nilfs_init_acl(inode, dir);
 419         if (unlikely(err))
 420                 goto failed_after_creation; /* never occur. When supporting
 421                                     nilfs_init_acl(), proper cancellation of
 422                                     above jobs should be considered */
 423
 424         return inode;
 425
 426  failed_after_creation:
 427         clear_nlink(inode);
 428         unlock_new_inode(inode);
 429         iput(inode);  /* raw_inode will be deleted through
 430                          nilfs_evict_inode() */
 431         goto failed;
 432
 433  failed_ifile_create_inode:
 434         make_bad_inode(inode);
 435         iput(inode);  /* if i_nlink == 1, generic_forget_inode() will be
 436                          called */
 437  failed:
 438         return ERR_PTR(err);
 439 }
 440
 441 void nilfs_set_inode_flags(struct inode *inode)
 442 {
 443         unsigned int flags = NILFS_I(inode)->i_flags;
 444         unsigned int new_fl = 0;
 445
 446         if (flags & FS_SYNC_FL)
 447                 new_fl |= S_SYNC;
 448         if (flags & FS_APPEND_FL)
 449                 new_fl |= S_APPEND;
 450         if (flags & FS_IMMUTABLE_FL)
 451                 new_fl |= S_IMMUTABLE;
 452         if (flags & FS_NOATIME_FL)
 453                 new_fl |= S_NOATIME;
 454         if (flags & FS_DIRSYNC_FL)
 455                 new_fl |= S_DIRSYNC;
 456         inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
 457                         S_NOATIME | S_DIRSYNC);
 458 }
 459
 460 int nilfs_read_inode_common(struct inode *inode,
 461                             struct nilfs_inode *raw_inode)
 462 {
 463         struct nilfs_inode_info *ii = NILFS_I(inode);
 464         int err;
 465
 466         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 467         i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 468         i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 469         set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 470         inode->i_size = le64_to_cpu(raw_inode->i_size);
 471         inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 472         inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 473         inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 474         inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 475         inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 476         inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 477         if (inode->i_nlink == 0)
 478                 return -ESTALE; /* this inode is deleted */
 479
 480         inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 481         ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 482 #if 0
 483         ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 484         ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 485                 0 : le32_to_cpu(raw_inode->i_dir_acl);
 486 #endif
 487         ii->i_dir_start_lookup = 0;
 488         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 489
 490         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 491             S_ISLNK(inode->i_mode)) {
 492                 err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 493                 if (err < 0)
 494                         return err;
 495                 set_bit(NILFS_I_BMAP, &ii->i_state);
 496                 /* No lock is needed; iget() ensures it. */
 497         }
 498         return 0;
 499 }
 500
 501 static int __nilfs_read_inode(struct super_block *sb,
 502                               struct nilfs_root *root, unsigned long ino,
 503                               struct inode *inode)
 504 {
 505         struct the_nilfs *nilfs = sb->s_fs_info;
 506         struct buffer_head *bh;
 507         struct nilfs_inode *raw_inode;
 508         int err;
 509
 510         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 511         err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 512         if (unlikely(err))
 513                 goto bad_inode;
 514
 515         raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 516
 517         err = nilfs_read_inode_common(inode, raw_inode);
 518         if (err)
 519                 goto failed_unmap;
 520
 521         if (S_ISREG(inode->i_mode)) {
 522                 inode->i_op = &nilfs_file_inode_operations;
 523                 inode->i_fop = &nilfs_file_operations;
 524                 inode->i_mapping->a_ops = &nilfs_aops;
 525         } else if (S_ISDIR(inode->i_mode)) {
 526                 inode->i_op = &nilfs_dir_inode_operations;
 527                 inode->i_fop = &nilfs_dir_operations;
 528                 inode->i_mapping->a_ops = &nilfs_aops;
 529         } else if (S_ISLNK(inode->i_mode)) {
 530                 inode->i_op = &nilfs_symlink_inode_operations;
 531                 inode->i_mapping->a_ops = &nilfs_aops;
 532         } else {
 533                 inode->i_op = &nilfs_special_inode_operations;
 534                 init_special_inode(
 535                         inode, inode->i_mode,
 536                         huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 537         }
 538         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 539         brelse(bh);
 540         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 541         nilfs_set_inode_flags(inode);
 542         mapping_set_gfp_mask(inode->i_mapping,
 543                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 544         return 0;
 545
 546  failed_unmap:
 547         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 548         brelse(bh);
 549
 550  bad_inode:
 551         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 552         return err;
 553 }
 554
 555 static int nilfs_iget_test(struct inode *inode, void *opaque)
 556 {
 557         struct nilfs_iget_args *args = opaque;
 558         struct nilfs_inode_info *ii;
 559
 560         if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 561                 return 0;
 562
 563         ii = NILFS_I(inode);
 564         if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 565                 return !args->for_gc;
 566
 567         return args->for_gc && args->cno == ii->i_cno;
 568 }
 569
 570 static int nilfs_iget_set(struct inode *inode, void *opaque)
 571 {
 572         struct nilfs_iget_args *args = opaque;
 573
 574         inode->i_ino = args->ino;
 575         if (args->for_gc) {
 576                 NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
 577                 NILFS_I(inode)->i_cno = args->cno;
 578                 NILFS_I(inode)->i_root = NULL;
 579         } else {
 580                 if (args->root && args->ino == NILFS_ROOT_INO)
 581                         nilfs_get_root(args->root);
 582                 NILFS_I(inode)->i_root = args->root;
 583         }
 584         return 0;
 585 }
 586
 587 struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 588                             unsigned long ino)
 589 {
 590         struct nilfs_iget_args args = {
 591                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
 592         };
 593
 594         return ilookup5(sb, ino, nilfs_iget_test, &args);
 595 }
 596
 597 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 598                                 unsigned long ino)
 599 {
 600         struct nilfs_iget_args args = {
 601                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
 602         };
 603
 604         return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 605 }
 606
 607 struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 608                          unsigned long ino)
 609 {
 610         struct inode *inode;
 611         int err;
 612
 613         inode = nilfs_iget_locked(sb, root, ino);
 614         if (unlikely(!inode))
 615                 return ERR_PTR(-ENOMEM);
 616         if (!(inode->i_state & I_NEW))
 617                 return inode;
 618
 619         err = __nilfs_read_inode(sb, root, ino, inode);
 620         if (unlikely(err)) {
 621                 iget_failed(inode);
 622                 return ERR_PTR(err);
 623         }
 624         unlock_new_inode(inode);
 625         return inode;
 626 }
 627
 628 struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 629                                 __u64 cno)
 630 {
 631         struct nilfs_iget_args args = {
 632                 .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
 633         };
 634         struct inode *inode;
 635         int err;
 636
 637         inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 638         if (unlikely(!inode))
 639                 return ERR_PTR(-ENOMEM);
 640         if (!(inode->i_state & I_NEW))
 641                 return inode;
 642
 643         err = nilfs_init_gcinode(inode);
 644         if (unlikely(err)) {
 645                 iget_failed(inode);
 646                 return ERR_PTR(err);
 647         }
 648         unlock_new_inode(inode);
 649         return inode;
 650 }
 651
 652 void nilfs_write_inode_common(struct inode *inode,
 653                               struct nilfs_inode *raw_inode, int has_bmap)
 654 {
 655         struct nilfs_inode_info *ii = NILFS_I(inode);
 656
 657         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 658         raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 659         raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 660         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 661         raw_inode->i_size = cpu_to_le64(inode->i_size);
 662         raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 663         raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 664         raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 665         raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 666         raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 667
 668         raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 669         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 670
 671         if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 672                 struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 673
 674                 /* zero-fill unused portion in the case of super root block */
 675                 raw_inode->i_xattr = 0;
 676                 raw_inode->i_pad = 0;
 677                 memset((void *)raw_inode + sizeof(*raw_inode), 0,
 678                        nilfs->ns_inode_size - sizeof(*raw_inode));
 679         }
 680
 681         if (has_bmap)
 682                 nilfs_bmap_write(ii->i_bmap, raw_inode);
 683         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 684                 raw_inode->i_device_code =
 685                         cpu_to_le64(huge_encode_dev(inode->i_rdev));
 686         /* When extending inode, nilfs->ns_inode_size should be checked
 687            for substitutions of appended fields */
 688 }
 689
 690 void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 691 {
 692         ino_t ino = inode->i_ino;
 693         struct nilfs_inode_info *ii = NILFS_I(inode);
 694         struct inode *ifile = ii->i_root->ifile;
 695         struct nilfs_inode *raw_inode;
 696
 697         raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 698
 699         if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 700                 memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 701         if (flags & I_DIRTY_DATASYNC)
 702                 set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 703
 704         nilfs_write_inode_common(inode, raw_inode, 0);
 705                 /* XXX: call with has_bmap = 0 is a workaround to avoid
 706                    deadlock of bmap. This delays update of i_bmap to just
 707                    before writing */
 708         nilfs_ifile_unmap_inode(ifile, ino, ibh);
 709 }
 710
 711 #define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
 712
 713 static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 714                                 unsigned long from)
 715 {
 716         __u64 b;
 717         int ret;
 718
 719         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 720                 return;
 721 repeat:
 722         ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 723         if (ret == -ENOENT)
 724                 return;
 725         else if (ret < 0)
 726                 goto failed;
 727
 728         if (b < from)
 729                 return;
 730
 731         b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 732         ret = nilfs_bmap_truncate(ii->i_bmap, b);
 733         nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 734         if (!ret || (ret == -ENOMEM &&
 735                      nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 736                 goto repeat;
 737
 738 failed:
 739         nilfs_warning(ii->vfs_inode.i_sb, __func__,
 740                       "failed to truncate bmap (ino=%lu, err=%d)",
 741                       ii->vfs_inode.i_ino, ret);
 742 }
 743
 744 void nilfs_truncate(struct inode *inode)
 745 {
 746         unsigned long blkoff;
 747         unsigned int blocksize;
 748         struct nilfs_transaction_info ti;
 749         struct super_block *sb = inode->i_sb;
 750         struct nilfs_inode_info *ii = NILFS_I(inode);
 751
 752         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 753                 return;
 754         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 755                 return;
 756
 757         blocksize = sb->s_blocksize;
 758         blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 759         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 760
 761         block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 762
 763         nilfs_truncate_bmap(ii, blkoff);
 764
 765         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 766         if (IS_SYNC(inode))
 767                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
 768
 769         nilfs_mark_inode_dirty(inode);
 770         nilfs_set_file_dirty(inode, 0);
 771         nilfs_transaction_commit(sb);
 772         /* May construct a logical segment and may fail in sync mode.
 773            But truncate has no return value. */
 774 }
 775
 776 static void nilfs_clear_inode(struct inode *inode)
 777 {
 778         struct nilfs_inode_info *ii = NILFS_I(inode);
 779         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 780
 781         /*
 782          * Free resources allocated in nilfs_read_inode(), here.
 783          */
 784         BUG_ON(!list_empty(&ii->i_dirty));
 785         brelse(ii->i_bh);
 786         ii->i_bh = NULL;
 787
 788         if (mdi && mdi->mi_palloc_cache)
 789                 nilfs_palloc_destroy_cache(inode);
 790
 791         if (test_bit(NILFS_I_BMAP, &ii->i_state))
 792                 nilfs_bmap_clear(ii->i_bmap);
 793
 794         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 795
 796         if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 797                 nilfs_put_root(ii->i_root);
 798 }
 799
 800 void nilfs_evict_inode(struct inode *inode)
 801 {
 802         struct nilfs_transaction_info ti;
 803         struct super_block *sb = inode->i_sb;
 804         struct nilfs_inode_info *ii = NILFS_I(inode);
 805         int ret;
 806
 807         if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 808                 truncate_inode_pages_final(&inode->i_data);
 809                 clear_inode(inode);
 810                 nilfs_clear_inode(inode);
 811                 return;
 812         }
 813         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 814
 815         truncate_inode_pages_final(&inode->i_data);
 816
 817         /* TODO: some of the following operations may fail.  */
 818         nilfs_truncate_bmap(ii, 0);
 819         nilfs_mark_inode_dirty(inode);
 820         clear_inode(inode);
 821
 822         ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 823         if (!ret)
 824                 atomic64_dec(&ii->i_root->inodes_count);
 825
 826         nilfs_clear_inode(inode);
 827
 828         if (IS_SYNC(inode))
 829                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
 830         nilfs_transaction_commit(sb);
 831         /* May construct a logical segment and may fail in sync mode.
 832            But delete_inode has no return value. */
 833 }
 834
 835 int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
 836 {
 837         struct nilfs_transaction_info ti;
 838         struct inode *inode = d_inode(dentry);
 839         struct super_block *sb = inode->i_sb;
 840         int err;
 841
 842         err = inode_change_ok(inode, iattr);
 843         if (err)
 844                 return err;
 845
 846         err = nilfs_transaction_begin(sb, &ti, 0);
 847         if (unlikely(err))
 848                 return err;
 849
 850         if ((iattr->ia_valid & ATTR_SIZE) &&
 851             iattr->ia_size != i_size_read(inode)) {
 852                 inode_dio_wait(inode);
 853                 truncate_setsize(inode, iattr->ia_size);
 854                 nilfs_truncate(inode);
 855         }
 856
 857         setattr_copy(inode, iattr);
 858         mark_inode_dirty(inode);
 859
 860         if (iattr->ia_valid & ATTR_MODE) {
 861                 err = nilfs_acl_chmod(inode);
 862                 if (unlikely(err))
 863                         goto out_err;
 864         }
 865
 866         return nilfs_transaction_commit(sb);
 867
 868 out_err:
 869         nilfs_transaction_abort(sb);
 870         return err;
 871 }
 872
 873 int nilfs_permission(struct inode *inode, int mask)
 874 {
 875         struct nilfs_root *root = NILFS_I(inode)->i_root;
 876         if ((mask & MAY_WRITE) && root &&
 877             root->cno != NILFS_CPTREE_CURRENT_CNO)
 878                 return -EROFS; /* snapshot is not writable */
 879
 880         return generic_permission(inode, mask);
 881 }
 882
 883 int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
 884 {
 885         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 886         struct nilfs_inode_info *ii = NILFS_I(inode);
 887         int err;
 888
 889         spin_lock(&nilfs->ns_inode_lock);
 890         if (ii->i_bh == NULL) {
 891                 spin_unlock(&nilfs->ns_inode_lock);
 892                 err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
 893                                                   inode->i_ino, pbh);
 894                 if (unlikely(err))
 895                         return err;
 896                 spin_lock(&nilfs->ns_inode_lock);
 897                 if (ii->i_bh == NULL)
 898                         ii->i_bh = *pbh;
 899                 else {
 900                         brelse(*pbh);
 901                         *pbh = ii->i_bh;
 902                 }
 903         } else
 904                 *pbh = ii->i_bh;
 905
 906         get_bh(*pbh);
 907         spin_unlock(&nilfs->ns_inode_lock);
 908         return 0;
 909 }
 910
 911 int nilfs_inode_dirty(struct inode *inode)
 912 {
 913         struct nilfs_inode_info *ii = NILFS_I(inode);
 914         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 915         int ret = 0;
 916
 917         if (!list_empty(&ii->i_dirty)) {
 918                 spin_lock(&nilfs->ns_inode_lock);
 919                 ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
 920                         test_bit(NILFS_I_BUSY, &ii->i_state);
 921                 spin_unlock(&nilfs->ns_inode_lock);
 922         }
 923         return ret;
 924 }
 925
 926 int nilfs_set_file_dirty(struct inode *inode, unsigned nr_dirty)
 927 {
 928         struct nilfs_inode_info *ii = NILFS_I(inode);
 929         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 930
 931         atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
 932
 933         if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
 934                 return 0;
 935
 936         spin_lock(&nilfs->ns_inode_lock);
 937         if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
 938             !test_bit(NILFS_I_BUSY, &ii->i_state)) {
 939                 /* Because this routine may race with nilfs_dispose_list(),
 940                    we have to check NILFS_I_QUEUED here, too. */
 941                 if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
 942                         /* This will happen when somebody is freeing
 943                            this inode. */
 944                         nilfs_warning(inode->i_sb, __func__,
 945                                       "cannot get inode (ino=%lu)\n",
 946                                       inode->i_ino);
 947                         spin_unlock(&nilfs->ns_inode_lock);
 948                         return -EINVAL; /* NILFS_I_DIRTY may remain for
 949                                            freeing inode */
 950                 }
 951                 list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
 952                 set_bit(NILFS_I_QUEUED, &ii->i_state);
 953         }
 954         spin_unlock(&nilfs->ns_inode_lock);
 955         return 0;
 956 }
 957
 958 int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
 959 {
 960         struct buffer_head *ibh;
 961         int err;
 962
 963         err = nilfs_load_inode_block(inode, &ibh);
 964         if (unlikely(err)) {
 965                 nilfs_warning(inode->i_sb, __func__,
 966                               "failed to reget inode block.\n");
 967                 return err;
 968         }
 969         nilfs_update_inode(inode, ibh, flags);
 970         mark_buffer_dirty(ibh);
 971         nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
 972         brelse(ibh);
 973         return 0;
 974 }
 975
 976 /**
 977  * nilfs_dirty_inode - reflect changes on given inode to an inode block.
 978  * @inode: inode of the file to be registered.
 979  *
 980  * nilfs_dirty_inode() loads a inode block containing the specified
 981  * @inode and copies data from a nilfs_inode to a corresponding inode
 982  * entry in the inode block. This operation is excluded from the segment
 983  * construction. This function can be called both as a single operation
 984  * and as a part of indivisible file operations.
 985  */
 986 void nilfs_dirty_inode(struct inode *inode, int flags)
 987 {
 988         struct nilfs_transaction_info ti;
 989         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 990
 991         if (is_bad_inode(inode)) {
 992                 nilfs_warning(inode->i_sb, __func__,
 993                               "tried to mark bad_inode dirty. ignored.\n");
 994                 dump_stack();
 995                 return;
 996         }
 997         if (mdi) {
 998                 nilfs_mdt_mark_dirty(inode);
 999                 return;
1000         }
1001         nilfs_transaction_begin(inode->i_sb, &ti, 0);
1002         __nilfs_mark_inode_dirty(inode, flags);
1003         nilfs_transaction_commit(inode->i_sb); /* never fails */
1004 }
1005
1006 int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1007                  __u64 start, __u64 len)
1008 {
1009         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1010         __u64 logical = 0, phys = 0, size = 0;
1011         __u32 flags = 0;
1012         loff_t isize;
1013         sector_t blkoff, end_blkoff;
1014         sector_t delalloc_blkoff;
1015         unsigned long delalloc_blklen;
1016         unsigned int blkbits = inode->i_blkbits;
1017         int ret, n;
1018
1019         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
1020         if (ret)
1021                 return ret;
1022
1023         mutex_lock(&inode->i_mutex);
1024
1025         isize = i_size_read(inode);
1026
1027         blkoff = start >> blkbits;
1028         end_blkoff = (start + len - 1) >> blkbits;
1029
1030         delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1031                                                         &delalloc_blkoff);
1032
1033         do {
1034                 __u64 blkphy;
1035                 unsigned int maxblocks;
1036
1037                 if (delalloc_blklen && blkoff == delalloc_blkoff) {
1038                         if (size) {
1039                                 /* End of the current extent */
1040                                 ret = fiemap_fill_next_extent(
1041                                         fieinfo, logical, phys, size, flags);
1042                                 if (ret)
1043                                         break;
1044                         }
1045                         if (blkoff > end_blkoff)
1046                                 break;
1047
1048                         flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1049                         logical = blkoff << blkbits;
1050                         phys = 0;
1051                         size = delalloc_blklen << blkbits;
1052
1053                         blkoff = delalloc_blkoff + delalloc_blklen;
1054                         delalloc_blklen = nilfs_find_uncommitted_extent(
1055                                 inode, blkoff, &delalloc_blkoff);
1056                         continue;
1057                 }
1058
1059                 /*
1060                  * Limit the number of blocks that we look up so as
1061                  * not to get into the next delayed allocation extent.
1062                  */
1063                 maxblocks = INT_MAX;
1064                 if (delalloc_blklen)
1065                         maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1066                                           maxblocks);
1067                 blkphy = 0;
1068
1069                 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1070                 n = nilfs_bmap_lookup_contig(
1071                         NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1072                 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1073
1074                 if (n < 0) {
1075                         int past_eof;
1076
1077                         if (unlikely(n != -ENOENT))
1078                                 break; /* error */
1079
1080                         /* HOLE */
1081                         blkoff++;
1082                         past_eof = ((blkoff << blkbits) >= isize);
1083
1084                         if (size) {
1085                                 /* End of the current extent */
1086
1087                                 if (past_eof)
1088                                         flags |= FIEMAP_EXTENT_LAST;
1089
1090                                 ret = fiemap_fill_next_extent(
1091                                         fieinfo, logical, phys, size, flags);
1092                                 if (ret)
1093                                         break;
1094                                 size = 0;
1095                         }
1096                         if (blkoff > end_blkoff || past_eof)
1097                                 break;
1098                 } else {
1099                         if (size) {
1100                                 if (phys && blkphy << blkbits == phys + size) {
1101                                         /* The current extent goes on */
1102                                         size += n << blkbits;
1103                                 } else {
1104                                         /* Terminate the current extent */
1105                                         ret = fiemap_fill_next_extent(
1106                                                 fieinfo, logical, phys, size,
1107                                                 flags);
1108                                         if (ret || blkoff > end_blkoff)
1109                                                 break;
1110
1111                                         /* Start another extent */
1112                                         flags = FIEMAP_EXTENT_MERGED;
1113                                         logical = blkoff << blkbits;
1114                                         phys = blkphy << blkbits;
1115                                         size = n << blkbits;
1116                                 }
1117                         } else {
1118                                 /* Start a new extent */
1119                                 flags = FIEMAP_EXTENT_MERGED;
1120                                 logical = blkoff << blkbits;
1121                                 phys = blkphy << blkbits;
1122                                 size = n << blkbits;
1123                         }
1124                         blkoff += n;
1125                 }
1126                 cond_resched();
1127         } while (true);
1128
1129         /* If ret is 1 then we just hit the end of the extent array */
1130         if (ret == 1)
1131                 ret = 0;
1132
1133         mutex_unlock(&inode->i_mutex);
1134         return ret;
1135 }