fs/nilfs2/inode.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * inode.c - NILFS inode operations.
   4  *
   5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6  *
   7  * Written by Ryusuke Konishi.
   8  *
   9  */
  10
  11 #include <linux/buffer_head.h>
  12 #include <linux/gfp.h>
  13 #include <linux/mpage.h>
  14 #include <linux/pagemap.h>
  15 #include <linux/writeback.h>
  16 #include <linux/uio.h>
  17 #include <linux/fiemap.h>
  18 #include "nilfs.h"
  19 #include "btnode.h"
  20 #include "segment.h"
  21 #include "page.h"
  22 #include "mdt.h"
  23 #include "cpfile.h"
  24 #include "ifile.h"
  25
  26 /**
  27  * struct nilfs_iget_args - arguments used during comparison between inodes
  28  * @ino: inode number
  29  * @cno: checkpoint number
  30  * @root: pointer on NILFS root object (mounted checkpoint)
  31  * @for_gc: inode for GC flag
  32  */
  33 struct nilfs_iget_args {
  34         u64 ino;
  35         __u64 cno;
  36         struct nilfs_root *root;
  37         int for_gc;
  38 };
  39
  40 static int nilfs_iget_test(struct inode *inode, void *opaque);
  41
  42 void nilfs_inode_add_blocks(struct inode *inode, int n)
  43 {
  44         struct nilfs_root *root = NILFS_I(inode)->i_root;
  45
  46         inode_add_bytes(inode, i_blocksize(inode) * n);
  47         if (root)
  48                 atomic64_add(n, &root->blocks_count);
  49 }
  50
  51 void nilfs_inode_sub_blocks(struct inode *inode, int n)
  52 {
  53         struct nilfs_root *root = NILFS_I(inode)->i_root;
  54
  55         inode_sub_bytes(inode, i_blocksize(inode) * n);
  56         if (root)
  57                 atomic64_sub(n, &root->blocks_count);
  58 }
  59
  60 /**
  61  * nilfs_get_block() - get a file block on the filesystem (callback function)
  62  * @inode - inode struct of the target file
  63  * @blkoff - file block number
  64  * @bh_result - buffer head to be mapped on
  65  * @create - indicate whether allocating the block or not when it has not
  66  *      been allocated yet.
  67  *
  68  * This function does not issue actual read request of the specified data
  69  * block. It is done by VFS.
  70  */
  71 int nilfs_get_block(struct inode *inode, sector_t blkoff,
  72                     struct buffer_head *bh_result, int create)
  73 {
  74         struct nilfs_inode_info *ii = NILFS_I(inode);
  75         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  76         __u64 blknum = 0;
  77         int err = 0, ret;
  78         unsigned int maxblocks = bh_result->b_size >> inode->i_blkbits;
  79
  80         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  81         ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  82         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  83         if (ret >= 0) { /* found */
  84                 map_bh(bh_result, inode->i_sb, blknum);
  85                 if (ret > 0)
  86                         bh_result->b_size = (ret << inode->i_blkbits);
  87                 goto out;
  88         }
  89         /* data block was not found */
  90         if (ret == -ENOENT && create) {
  91                 struct nilfs_transaction_info ti;
  92
  93                 bh_result->b_blocknr = 0;
  94                 err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
  95                 if (unlikely(err))
  96                         goto out;
  97                 err = nilfs_bmap_insert(ii->i_bmap, blkoff,
  98                                         (unsigned long)bh_result);
  99                 if (unlikely(err != 0)) {
 100                         if (err == -EEXIST) {
 101                                 /*
 102                                  * The get_block() function could be called
 103                                  * from multiple callers for an inode.
 104                                  * However, the page having this block must
 105                                  * be locked in this case.
 106                                  */
 107                                 nilfs_warn(inode->i_sb,
 108                                            "%s (ino=%lu): a race condition while inserting a data block at offset=%llu",
 109                                            __func__, inode->i_ino,
 110                                            (unsigned long long)blkoff);
 111                                 err = 0;
 112                         }
 113                         nilfs_transaction_abort(inode->i_sb);
 114                         goto out;
 115                 }
 116                 nilfs_mark_inode_dirty_sync(inode);
 117                 nilfs_transaction_commit(inode->i_sb); /* never fails */
 118                 /* Error handling should be detailed */
 119                 set_buffer_new(bh_result);
 120                 set_buffer_delay(bh_result);
 121                 map_bh(bh_result, inode->i_sb, 0);
 122                 /* Disk block number must be changed to proper value */
 123
 124         } else if (ret == -ENOENT) {
 125                 /*
 126                  * not found is not error (e.g. hole); must return without
 127                  * the mapped state flag.
 128                  */
 129                 ;
 130         } else {
 131                 err = ret;
 132         }
 133
 134  out:
 135         return err;
 136 }
 137
 138 /**
 139  * nilfs_readpage() - implement readpage() method of nilfs_aops {}
 140  * address_space_operations.
 141  * @file - file struct of the file to be read
 142  * @page - the page to be read
 143  */
 144 static int nilfs_readpage(struct file *file, struct page *page)
 145 {
 146         return mpage_readpage(page, nilfs_get_block);
 147 }
 148
 149 static void nilfs_readahead(struct readahead_control *rac)
 150 {
 151         mpage_readahead(rac, nilfs_get_block);
 152 }
 153
 154 static int nilfs_writepages(struct address_space *mapping,
 155                             struct writeback_control *wbc)
 156 {
 157         struct inode *inode = mapping->host;
 158         int err = 0;
 159
 160         if (sb_rdonly(inode->i_sb)) {
 161                 nilfs_clear_dirty_pages(mapping, false);
 162                 return -EROFS;
 163         }
 164
 165         if (wbc->sync_mode == WB_SYNC_ALL)
 166                 err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 167                                                     wbc->range_start,
 168                                                     wbc->range_end);
 169         return err;
 170 }
 171
 172 static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 173 {
 174         struct inode *inode = page->mapping->host;
 175         int err;
 176
 177         if (sb_rdonly(inode->i_sb)) {
 178                 /*
 179                  * It means that filesystem was remounted in read-only
 180                  * mode because of error or metadata corruption. But we
 181                  * have dirty pages that try to be flushed in background.
 182                  * So, here we simply discard this dirty page.
 183                  */
 184                 nilfs_clear_dirty_page(page, false);
 185                 unlock_page(page);
 186                 return -EROFS;
 187         }
 188
 189         redirty_page_for_writepage(wbc, page);
 190         unlock_page(page);
 191
 192         if (wbc->sync_mode == WB_SYNC_ALL) {
 193                 err = nilfs_construct_segment(inode->i_sb);
 194                 if (unlikely(err))
 195                         return err;
 196         } else if (wbc->for_reclaim)
 197                 nilfs_flush_segment(inode->i_sb, inode->i_ino);
 198
 199         return 0;
 200 }
 201
 202 static int nilfs_set_page_dirty(struct page *page)
 203 {
 204         struct inode *inode = page->mapping->host;
 205         int ret = __set_page_dirty_nobuffers(page);
 206
 207         if (page_has_buffers(page)) {
 208                 unsigned int nr_dirty = 0;
 209                 struct buffer_head *bh, *head;
 210
 211                 /*
 212                  * This page is locked by callers, and no other thread
 213                  * concurrently marks its buffers dirty since they are
 214                  * only dirtied through routines in fs/buffer.c in
 215                  * which call sites of mark_buffer_dirty are protected
 216                  * by page lock.
 217                  */
 218                 bh = head = page_buffers(page);
 219                 do {
 220                         /* Do not mark hole blocks dirty */
 221                         if (buffer_dirty(bh) || !buffer_mapped(bh))
 222                                 continue;
 223
 224                         set_buffer_dirty(bh);
 225                         nr_dirty++;
 226                 } while (bh = bh->b_this_page, bh != head);
 227
 228                 if (nr_dirty)
 229                         nilfs_set_file_dirty(inode, nr_dirty);
 230         } else if (ret) {
 231                 unsigned int nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
 232
 233                 nilfs_set_file_dirty(inode, nr_dirty);
 234         }
 235         return ret;
 236 }
 237
 238 void nilfs_write_failed(struct address_space *mapping, loff_t to)
 239 {
 240         struct inode *inode = mapping->host;
 241
 242         if (to > inode->i_size) {
 243                 truncate_pagecache(inode, inode->i_size);
 244                 nilfs_truncate(inode);
 245         }
 246 }
 247
 248 static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 249                              loff_t pos, unsigned len, unsigned flags,
 250                              struct page **pagep, void **fsdata)
 251
 252 {
 253         struct inode *inode = mapping->host;
 254         int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 255
 256         if (unlikely(err))
 257                 return err;
 258
 259         err = block_write_begin(mapping, pos, len, flags, pagep,
 260                                 nilfs_get_block);
 261         if (unlikely(err)) {
 262                 nilfs_write_failed(mapping, pos + len);
 263                 nilfs_transaction_abort(inode->i_sb);
 264         }
 265         return err;
 266 }
 267
 268 static int nilfs_write_end(struct file *file, struct address_space *mapping,
 269                            loff_t pos, unsigned len, unsigned copied,
 270                            struct page *page, void *fsdata)
 271 {
 272         struct inode *inode = mapping->host;
 273         unsigned int start = pos & (PAGE_SIZE - 1);
 274         unsigned int nr_dirty;
 275         int err;
 276
 277         nr_dirty = nilfs_page_count_clean_buffers(page, start,
 278                                                   start + copied);
 279         copied = generic_write_end(file, mapping, pos, len, copied, page,
 280                                    fsdata);
 281         nilfs_set_file_dirty(inode, nr_dirty);
 282         err = nilfs_transaction_commit(inode->i_sb);
 283         return err ? : copied;
 284 }
 285
 286 static ssize_t
 287 nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 288 {
 289         struct inode *inode = file_inode(iocb->ki_filp);
 290
 291         if (iov_iter_rw(iter) == WRITE)
 292                 return 0;
 293
 294         /* Needs synchronization with the cleaner */
 295         return blockdev_direct_IO(iocb, inode, iter, nilfs_get_block);
 296 }
 297
 298 const struct address_space_operations nilfs_aops = {
 299         .writepage              = nilfs_writepage,
 300         .readpage               = nilfs_readpage,
 301         .writepages             = nilfs_writepages,
 302         .set_page_dirty         = nilfs_set_page_dirty,
 303         .readahead              = nilfs_readahead,
 304         .write_begin            = nilfs_write_begin,
 305         .write_end              = nilfs_write_end,
 306         /* .releasepage         = nilfs_releasepage, */
 307         .invalidatepage         = block_invalidatepage,
 308         .direct_IO              = nilfs_direct_IO,
 309         .is_partially_uptodate  = block_is_partially_uptodate,
 310 };
 311
 312 static int nilfs_insert_inode_locked(struct inode *inode,
 313                                      struct nilfs_root *root,
 314                                      unsigned long ino)
 315 {
 316         struct nilfs_iget_args args = {
 317                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
 318         };
 319
 320         return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
 321 }
 322
 323 struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 324 {
 325         struct super_block *sb = dir->i_sb;
 326         struct the_nilfs *nilfs = sb->s_fs_info;
 327         struct inode *inode;
 328         struct nilfs_inode_info *ii;
 329         struct nilfs_root *root;
 330         int err = -ENOMEM;
 331         ino_t ino;
 332
 333         inode = new_inode(sb);
 334         if (unlikely(!inode))
 335                 goto failed;
 336
 337         mapping_set_gfp_mask(inode->i_mapping,
 338                            mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 339
 340         root = NILFS_I(dir)->i_root;
 341         ii = NILFS_I(inode);
 342         ii->i_state = BIT(NILFS_I_NEW);
 343         ii->i_root = root;
 344
 345         err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
 346         if (unlikely(err))
 347                 goto failed_ifile_create_inode;
 348         /* reference count of i_bh inherits from nilfs_mdt_read_block() */
 349
 350         atomic64_inc(&root->inodes_count);
 351         inode_init_owner(&init_user_ns, inode, dir, mode);
 352         inode->i_ino = ino;
 353         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 354
 355         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 356                 err = nilfs_bmap_read(ii->i_bmap, NULL);
 357                 if (err < 0)
 358                         goto failed_after_creation;
 359
 360                 set_bit(NILFS_I_BMAP, &ii->i_state);
 361                 /* No lock is needed; iget() ensures it. */
 362         }
 363
 364         ii->i_flags = nilfs_mask_flags(
 365                 mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 366
 367         /* ii->i_file_acl = 0; */
 368         /* ii->i_dir_acl = 0; */
 369         ii->i_dir_start_lookup = 0;
 370         nilfs_set_inode_flags(inode);
 371         spin_lock(&nilfs->ns_next_gen_lock);
 372         inode->i_generation = nilfs->ns_next_generation++;
 373         spin_unlock(&nilfs->ns_next_gen_lock);
 374         if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
 375                 err = -EIO;
 376                 goto failed_after_creation;
 377         }
 378
 379         err = nilfs_init_acl(inode, dir);
 380         if (unlikely(err))
 381                 /*
 382                  * Never occur.  When supporting nilfs_init_acl(),
 383                  * proper cancellation of above jobs should be considered.
 384                  */
 385                 goto failed_after_creation;
 386
 387         return inode;
 388
 389  failed_after_creation:
 390         clear_nlink(inode);
 391         if (inode->i_state & I_NEW)
 392                 unlock_new_inode(inode);
 393         iput(inode);  /*
 394                        * raw_inode will be deleted through
 395                        * nilfs_evict_inode().
 396                        */
 397         goto failed;
 398
 399  failed_ifile_create_inode:
 400         make_bad_inode(inode);
 401         iput(inode);
 402  failed:
 403         return ERR_PTR(err);
 404 }
 405
 406 void nilfs_set_inode_flags(struct inode *inode)
 407 {
 408         unsigned int flags = NILFS_I(inode)->i_flags;
 409         unsigned int new_fl = 0;
 410
 411         if (flags & FS_SYNC_FL)
 412                 new_fl |= S_SYNC;
 413         if (flags & FS_APPEND_FL)
 414                 new_fl |= S_APPEND;
 415         if (flags & FS_IMMUTABLE_FL)
 416                 new_fl |= S_IMMUTABLE;
 417         if (flags & FS_NOATIME_FL)
 418                 new_fl |= S_NOATIME;
 419         if (flags & FS_DIRSYNC_FL)
 420                 new_fl |= S_DIRSYNC;
 421         inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
 422                         S_NOATIME | S_DIRSYNC);
 423 }
 424
 425 int nilfs_read_inode_common(struct inode *inode,
 426                             struct nilfs_inode *raw_inode)
 427 {
 428         struct nilfs_inode_info *ii = NILFS_I(inode);
 429         int err;
 430
 431         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 432         i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 433         i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 434         set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 435         inode->i_size = le64_to_cpu(raw_inode->i_size);
 436         inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 437         inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 438         inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 439         inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 440         inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 441         inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 442         if (inode->i_nlink == 0)
 443                 return -ESTALE; /* this inode is deleted */
 444
 445         inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 446         ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 447 #if 0
 448         ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 449         ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 450                 0 : le32_to_cpu(raw_inode->i_dir_acl);
 451 #endif
 452         ii->i_dir_start_lookup = 0;
 453         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 454
 455         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 456             S_ISLNK(inode->i_mode)) {
 457                 err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 458                 if (err < 0)
 459                         return err;
 460                 set_bit(NILFS_I_BMAP, &ii->i_state);
 461                 /* No lock is needed; iget() ensures it. */
 462         }
 463         return 0;
 464 }
 465
 466 static int __nilfs_read_inode(struct super_block *sb,
 467                               struct nilfs_root *root, unsigned long ino,
 468                               struct inode *inode)
 469 {
 470         struct the_nilfs *nilfs = sb->s_fs_info;
 471         struct buffer_head *bh;
 472         struct nilfs_inode *raw_inode;
 473         int err;
 474
 475         down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 476         err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 477         if (unlikely(err))
 478                 goto bad_inode;
 479
 480         raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 481
 482         err = nilfs_read_inode_common(inode, raw_inode);
 483         if (err)
 484                 goto failed_unmap;
 485
 486         if (S_ISREG(inode->i_mode)) {
 487                 inode->i_op = &nilfs_file_inode_operations;
 488                 inode->i_fop = &nilfs_file_operations;
 489                 inode->i_mapping->a_ops = &nilfs_aops;
 490         } else if (S_ISDIR(inode->i_mode)) {
 491                 inode->i_op = &nilfs_dir_inode_operations;
 492                 inode->i_fop = &nilfs_dir_operations;
 493                 inode->i_mapping->a_ops = &nilfs_aops;
 494         } else if (S_ISLNK(inode->i_mode)) {
 495                 inode->i_op = &nilfs_symlink_inode_operations;
 496                 inode_nohighmem(inode);
 497                 inode->i_mapping->a_ops = &nilfs_aops;
 498         } else {
 499                 inode->i_op = &nilfs_special_inode_operations;
 500                 init_special_inode(
 501                         inode, inode->i_mode,
 502                         huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 503         }
 504         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 505         brelse(bh);
 506         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 507         nilfs_set_inode_flags(inode);
 508         mapping_set_gfp_mask(inode->i_mapping,
 509                            mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 510         return 0;
 511
 512  failed_unmap:
 513         nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 514         brelse(bh);
 515
 516  bad_inode:
 517         up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 518         return err;
 519 }
 520
 521 static int nilfs_iget_test(struct inode *inode, void *opaque)
 522 {
 523         struct nilfs_iget_args *args = opaque;
 524         struct nilfs_inode_info *ii;
 525
 526         if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 527                 return 0;
 528
 529         ii = NILFS_I(inode);
 530         if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 531                 return !args->for_gc;
 532
 533         return args->for_gc && args->cno == ii->i_cno;
 534 }
 535
 536 static int nilfs_iget_set(struct inode *inode, void *opaque)
 537 {
 538         struct nilfs_iget_args *args = opaque;
 539
 540         inode->i_ino = args->ino;
 541         if (args->for_gc) {
 542                 NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
 543                 NILFS_I(inode)->i_cno = args->cno;
 544                 NILFS_I(inode)->i_root = NULL;
 545         } else {
 546                 if (args->root && args->ino == NILFS_ROOT_INO)
 547                         nilfs_get_root(args->root);
 548                 NILFS_I(inode)->i_root = args->root;
 549         }
 550         return 0;
 551 }
 552
 553 struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 554                             unsigned long ino)
 555 {
 556         struct nilfs_iget_args args = {
 557                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
 558         };
 559
 560         return ilookup5(sb, ino, nilfs_iget_test, &args);
 561 }
 562
 563 struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 564                                 unsigned long ino)
 565 {
 566         struct nilfs_iget_args args = {
 567                 .ino = ino, .root = root, .cno = 0, .for_gc = 0
 568         };
 569
 570         return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 571 }
 572
 573 struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 574                          unsigned long ino)
 575 {
 576         struct inode *inode;
 577         int err;
 578
 579         inode = nilfs_iget_locked(sb, root, ino);
 580         if (unlikely(!inode))
 581                 return ERR_PTR(-ENOMEM);
 582         if (!(inode->i_state & I_NEW))
 583                 return inode;
 584
 585         err = __nilfs_read_inode(sb, root, ino, inode);
 586         if (unlikely(err)) {
 587                 iget_failed(inode);
 588                 return ERR_PTR(err);
 589         }
 590         unlock_new_inode(inode);
 591         return inode;
 592 }
 593
 594 struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 595                                 __u64 cno)
 596 {
 597         struct nilfs_iget_args args = {
 598                 .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
 599         };
 600         struct inode *inode;
 601         int err;
 602
 603         inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 604         if (unlikely(!inode))
 605                 return ERR_PTR(-ENOMEM);
 606         if (!(inode->i_state & I_NEW))
 607                 return inode;
 608
 609         err = nilfs_init_gcinode(inode);
 610         if (unlikely(err)) {
 611                 iget_failed(inode);
 612                 return ERR_PTR(err);
 613         }
 614         unlock_new_inode(inode);
 615         return inode;
 616 }
 617
 618 void nilfs_write_inode_common(struct inode *inode,
 619                               struct nilfs_inode *raw_inode, int has_bmap)
 620 {
 621         struct nilfs_inode_info *ii = NILFS_I(inode);
 622
 623         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 624         raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 625         raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 626         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 627         raw_inode->i_size = cpu_to_le64(inode->i_size);
 628         raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 629         raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 630         raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 631         raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 632         raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 633
 634         raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 635         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 636
 637         if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 638                 struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 639
 640                 /* zero-fill unused portion in the case of super root block */
 641                 raw_inode->i_xattr = 0;
 642                 raw_inode->i_pad = 0;
 643                 memset((void *)raw_inode + sizeof(*raw_inode), 0,
 644                        nilfs->ns_inode_size - sizeof(*raw_inode));
 645         }
 646
 647         if (has_bmap)
 648                 nilfs_bmap_write(ii->i_bmap, raw_inode);
 649         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 650                 raw_inode->i_device_code =
 651                         cpu_to_le64(huge_encode_dev(inode->i_rdev));
 652         /*
 653          * When extending inode, nilfs->ns_inode_size should be checked
 654          * for substitutions of appended fields.
 655          */
 656 }
 657
 658 void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 659 {
 660         ino_t ino = inode->i_ino;
 661         struct nilfs_inode_info *ii = NILFS_I(inode);
 662         struct inode *ifile = ii->i_root->ifile;
 663         struct nilfs_inode *raw_inode;
 664
 665         raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 666
 667         if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 668                 memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 669         if (flags & I_DIRTY_DATASYNC)
 670                 set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 671
 672         nilfs_write_inode_common(inode, raw_inode, 0);
 673                 /*
 674                  * XXX: call with has_bmap = 0 is a workaround to avoid
 675                  * deadlock of bmap.  This delays update of i_bmap to just
 676                  * before writing.
 677                  */
 678
 679         nilfs_ifile_unmap_inode(ifile, ino, ibh);
 680 }
 681
 682 #define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
 683
 684 static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 685                                 unsigned long from)
 686 {
 687         __u64 b;
 688         int ret;
 689
 690         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 691                 return;
 692 repeat:
 693         ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 694         if (ret == -ENOENT)
 695                 return;
 696         else if (ret < 0)
 697                 goto failed;
 698
 699         if (b < from)
 700                 return;
 701
 702         b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 703         ret = nilfs_bmap_truncate(ii->i_bmap, b);
 704         nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 705         if (!ret || (ret == -ENOMEM &&
 706                      nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 707                 goto repeat;
 708
 709 failed:
 710         nilfs_warn(ii->vfs_inode.i_sb, "error %d truncating bmap (ino=%lu)",
 711                    ret, ii->vfs_inode.i_ino);
 712 }
 713
 714 void nilfs_truncate(struct inode *inode)
 715 {
 716         unsigned long blkoff;
 717         unsigned int blocksize;
 718         struct nilfs_transaction_info ti;
 719         struct super_block *sb = inode->i_sb;
 720         struct nilfs_inode_info *ii = NILFS_I(inode);
 721
 722         if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 723                 return;
 724         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 725                 return;
 726
 727         blocksize = sb->s_blocksize;
 728         blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 729         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 730
 731         block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 732
 733         nilfs_truncate_bmap(ii, blkoff);
 734
 735         inode->i_mtime = inode->i_ctime = current_time(inode);
 736         if (IS_SYNC(inode))
 737                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
 738
 739         nilfs_mark_inode_dirty(inode);
 740         nilfs_set_file_dirty(inode, 0);
 741         nilfs_transaction_commit(sb);
 742         /*
 743          * May construct a logical segment and may fail in sync mode.
 744          * But truncate has no return value.
 745          */
 746 }
 747
 748 static void nilfs_clear_inode(struct inode *inode)
 749 {
 750         struct nilfs_inode_info *ii = NILFS_I(inode);
 751
 752         /*
 753          * Free resources allocated in nilfs_read_inode(), here.
 754          */
 755         BUG_ON(!list_empty(&ii->i_dirty));
 756         brelse(ii->i_bh);
 757         ii->i_bh = NULL;
 758
 759         if (nilfs_is_metadata_file_inode(inode))
 760                 nilfs_mdt_clear(inode);
 761
 762         if (test_bit(NILFS_I_BMAP, &ii->i_state))
 763                 nilfs_bmap_clear(ii->i_bmap);
 764
 765         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 766
 767         if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 768                 nilfs_put_root(ii->i_root);
 769 }
 770
 771 void nilfs_evict_inode(struct inode *inode)
 772 {
 773         struct nilfs_transaction_info ti;
 774         struct super_block *sb = inode->i_sb;
 775         struct nilfs_inode_info *ii = NILFS_I(inode);
 776         int ret;
 777
 778         if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 779                 truncate_inode_pages_final(&inode->i_data);
 780                 clear_inode(inode);
 781                 nilfs_clear_inode(inode);
 782                 return;
 783         }
 784         nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 785
 786         truncate_inode_pages_final(&inode->i_data);
 787
 788         /* TODO: some of the following operations may fail.  */
 789         nilfs_truncate_bmap(ii, 0);
 790         nilfs_mark_inode_dirty(inode);
 791         clear_inode(inode);
 792
 793         ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 794         if (!ret)
 795                 atomic64_dec(&ii->i_root->inodes_count);
 796
 797         nilfs_clear_inode(inode);
 798
 799         if (IS_SYNC(inode))
 800                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
 801         nilfs_transaction_commit(sb);
 802         /*
 803          * May construct a logical segment and may fail in sync mode.
 804          * But delete_inode has no return value.
 805          */
 806 }
 807
 808 int nilfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 809                   struct iattr *iattr)
 810 {
 811         struct nilfs_transaction_info ti;
 812         struct inode *inode = d_inode(dentry);
 813         struct super_block *sb = inode->i_sb;
 814         int err;
 815
 816         err = setattr_prepare(&init_user_ns, dentry, iattr);
 817         if (err)
 818                 return err;
 819
 820         err = nilfs_transaction_begin(sb, &ti, 0);
 821         if (unlikely(err))
 822                 return err;
 823
 824         if ((iattr->ia_valid & ATTR_SIZE) &&
 825             iattr->ia_size != i_size_read(inode)) {
 826                 inode_dio_wait(inode);
 827                 truncate_setsize(inode, iattr->ia_size);
 828                 nilfs_truncate(inode);
 829         }
 830
 831         setattr_copy(&init_user_ns, inode, iattr);
 832         mark_inode_dirty(inode);
 833
 834         if (iattr->ia_valid & ATTR_MODE) {
 835                 err = nilfs_acl_chmod(inode);
 836                 if (unlikely(err))
 837                         goto out_err;
 838         }
 839
 840         return nilfs_transaction_commit(sb);
 841
 842 out_err:
 843         nilfs_transaction_abort(sb);
 844         return err;
 845 }
 846
 847 int nilfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
 848                      int mask)
 849 {
 850         struct nilfs_root *root = NILFS_I(inode)->i_root;
 851
 852         if ((mask & MAY_WRITE) && root &&
 853             root->cno != NILFS_CPTREE_CURRENT_CNO)
 854                 return -EROFS; /* snapshot is not writable */
 855
 856         return generic_permission(&init_user_ns, inode, mask);
 857 }
 858
 859 int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
 860 {
 861         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 862         struct nilfs_inode_info *ii = NILFS_I(inode);
 863         int err;
 864
 865         spin_lock(&nilfs->ns_inode_lock);
 866         if (ii->i_bh == NULL) {
 867                 spin_unlock(&nilfs->ns_inode_lock);
 868                 err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
 869                                                   inode->i_ino, pbh);
 870                 if (unlikely(err))
 871                         return err;
 872                 spin_lock(&nilfs->ns_inode_lock);
 873                 if (ii->i_bh == NULL)
 874                         ii->i_bh = *pbh;
 875                 else {
 876                         brelse(*pbh);
 877                         *pbh = ii->i_bh;
 878                 }
 879         } else
 880                 *pbh = ii->i_bh;
 881
 882         get_bh(*pbh);
 883         spin_unlock(&nilfs->ns_inode_lock);
 884         return 0;
 885 }
 886
 887 int nilfs_inode_dirty(struct inode *inode)
 888 {
 889         struct nilfs_inode_info *ii = NILFS_I(inode);
 890         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 891         int ret = 0;
 892
 893         if (!list_empty(&ii->i_dirty)) {
 894                 spin_lock(&nilfs->ns_inode_lock);
 895                 ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
 896                         test_bit(NILFS_I_BUSY, &ii->i_state);
 897                 spin_unlock(&nilfs->ns_inode_lock);
 898         }
 899         return ret;
 900 }
 901
 902 int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
 903 {
 904         struct nilfs_inode_info *ii = NILFS_I(inode);
 905         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 906
 907         atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
 908
 909         if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
 910                 return 0;
 911
 912         spin_lock(&nilfs->ns_inode_lock);
 913         if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
 914             !test_bit(NILFS_I_BUSY, &ii->i_state)) {
 915                 /*
 916                  * Because this routine may race with nilfs_dispose_list(),
 917                  * we have to check NILFS_I_QUEUED here, too.
 918                  */
 919                 if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
 920                         /*
 921                          * This will happen when somebody is freeing
 922                          * this inode.
 923                          */
 924                         nilfs_warn(inode->i_sb,
 925                                    "cannot set file dirty (ino=%lu): the file is being freed",
 926                                    inode->i_ino);
 927                         spin_unlock(&nilfs->ns_inode_lock);
 928                         return -EINVAL; /*
 929                                          * NILFS_I_DIRTY may remain for
 930                                          * freeing inode.
 931                                          */
 932                 }
 933                 list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
 934                 set_bit(NILFS_I_QUEUED, &ii->i_state);
 935         }
 936         spin_unlock(&nilfs->ns_inode_lock);
 937         return 0;
 938 }
 939
 940 int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
 941 {
 942         struct buffer_head *ibh;
 943         int err;
 944
 945         err = nilfs_load_inode_block(inode, &ibh);
 946         if (unlikely(err)) {
 947                 nilfs_warn(inode->i_sb,
 948                            "cannot mark inode dirty (ino=%lu): error %d loading inode block",
 949                            inode->i_ino, err);
 950                 return err;
 951         }
 952         nilfs_update_inode(inode, ibh, flags);
 953         mark_buffer_dirty(ibh);
 954         nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
 955         brelse(ibh);
 956         return 0;
 957 }
 958
 959 /**
 960  * nilfs_dirty_inode - reflect changes on given inode to an inode block.
 961  * @inode: inode of the file to be registered.
 962  *
 963  * nilfs_dirty_inode() loads a inode block containing the specified
 964  * @inode and copies data from a nilfs_inode to a corresponding inode
 965  * entry in the inode block. This operation is excluded from the segment
 966  * construction. This function can be called both as a single operation
 967  * and as a part of indivisible file operations.
 968  */
 969 void nilfs_dirty_inode(struct inode *inode, int flags)
 970 {
 971         struct nilfs_transaction_info ti;
 972         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 973
 974         if (is_bad_inode(inode)) {
 975                 nilfs_warn(inode->i_sb,
 976                            "tried to mark bad_inode dirty. ignored.");
 977                 dump_stack();
 978                 return;
 979         }
 980         if (mdi) {
 981                 nilfs_mdt_mark_dirty(inode);
 982                 return;
 983         }
 984         nilfs_transaction_begin(inode->i_sb, &ti, 0);
 985         __nilfs_mark_inode_dirty(inode, flags);
 986         nilfs_transaction_commit(inode->i_sb); /* never fails */
 987 }
 988
 989 int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 990                  __u64 start, __u64 len)
 991 {
 992         struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 993         __u64 logical = 0, phys = 0, size = 0;
 994         __u32 flags = 0;
 995         loff_t isize;
 996         sector_t blkoff, end_blkoff;
 997         sector_t delalloc_blkoff;
 998         unsigned long delalloc_blklen;
 999         unsigned int blkbits = inode->i_blkbits;
1000         int ret, n;
1001
1002         ret = fiemap_prep(inode, fieinfo, start, &len, 0);
1003         if (ret)
1004                 return ret;
1005
1006         inode_lock(inode);
1007
1008         isize = i_size_read(inode);
1009
1010         blkoff = start >> blkbits;
1011         end_blkoff = (start + len - 1) >> blkbits;
1012
1013         delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1014                                                         &delalloc_blkoff);
1015
1016         do {
1017                 __u64 blkphy;
1018                 unsigned int maxblocks;
1019
1020                 if (delalloc_blklen && blkoff == delalloc_blkoff) {
1021                         if (size) {
1022                                 /* End of the current extent */
1023                                 ret = fiemap_fill_next_extent(
1024                                         fieinfo, logical, phys, size, flags);
1025                                 if (ret)
1026                                         break;
1027                         }
1028                         if (blkoff > end_blkoff)
1029                                 break;
1030
1031                         flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1032                         logical = blkoff << blkbits;
1033                         phys = 0;
1034                         size = delalloc_blklen << blkbits;
1035
1036                         blkoff = delalloc_blkoff + delalloc_blklen;
1037                         delalloc_blklen = nilfs_find_uncommitted_extent(
1038                                 inode, blkoff, &delalloc_blkoff);
1039                         continue;
1040                 }
1041
1042                 /*
1043                  * Limit the number of blocks that we look up so as
1044                  * not to get into the next delayed allocation extent.
1045                  */
1046                 maxblocks = INT_MAX;
1047                 if (delalloc_blklen)
1048                         maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1049                                           maxblocks);
1050                 blkphy = 0;
1051
1052                 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1053                 n = nilfs_bmap_lookup_contig(
1054                         NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1055                 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1056
1057                 if (n < 0) {
1058                         int past_eof;
1059
1060                         if (unlikely(n != -ENOENT))
1061                                 break; /* error */
1062
1063                         /* HOLE */
1064                         blkoff++;
1065                         past_eof = ((blkoff << blkbits) >= isize);
1066
1067                         if (size) {
1068                                 /* End of the current extent */
1069
1070                                 if (past_eof)
1071                                         flags |= FIEMAP_EXTENT_LAST;
1072
1073                                 ret = fiemap_fill_next_extent(
1074                                         fieinfo, logical, phys, size, flags);
1075                                 if (ret)
1076                                         break;
1077                                 size = 0;
1078                         }
1079                         if (blkoff > end_blkoff || past_eof)
1080                                 break;
1081                 } else {
1082                         if (size) {
1083                                 if (phys && blkphy << blkbits == phys + size) {
1084                                         /* The current extent goes on */
1085                                         size += n << blkbits;
1086                                 } else {
1087                                         /* Terminate the current extent */
1088                                         ret = fiemap_fill_next_extent(
1089                                                 fieinfo, logical, phys, size,
1090                                                 flags);
1091                                         if (ret || blkoff > end_blkoff)
1092                                                 break;
1093
1094                                         /* Start another extent */
1095                                         flags = FIEMAP_EXTENT_MERGED;
1096                                         logical = blkoff << blkbits;
1097                                         phys = blkphy << blkbits;
1098                                         size = n << blkbits;
1099                                 }
1100                         } else {
1101                                 /* Start a new extent */
1102                                 flags = FIEMAP_EXTENT_MERGED;
1103                                 logical = blkoff << blkbits;
1104                                 phys = blkphy << blkbits;
1105                                 size = n << blkbits;
1106                         }
1107                         blkoff += n;
1108                 }
1109                 cond_resched();
1110         } while (true);
1111
1112         /* If ret is 1 then we just hit the end of the extent array */
1113         if (ret == 1)
1114                 ret = 0;
1115
1116         inode_unlock(inode);
1117         return ret;
1118 }