1 /* 2 * super.c - NILFS module and super block management. 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 * linux/fs/ext2/super.c 24 * 25 * Copyright (C) 1992, 1993, 1994, 1995 26 * Remy Card (card@masi.ibp.fr) 27 * Laboratoire MASI - Institut Blaise Pascal 28 * Universite Pierre et Marie Curie (Paris VI) 29 * 30 * from 31 * 32 * linux/fs/minix/inode.c 33 * 34 * Copyright (C) 1991, 1992 Linus Torvalds 35 * 36 * Big-endian to little-endian byte-swapping/bitmaps by 37 * David S. Miller (davem@caip.rutgers.edu), 1995 38 */ 39 40 #include <linux/module.h> 41 #include <linux/string.h> 42 #include <linux/slab.h> 43 #include <linux/init.h> 44 #include <linux/blkdev.h> 45 #include <linux/parser.h> 46 #include <linux/random.h> 47 #include <linux/crc32.h> 48 #include <linux/vfs.h> 49 #include <linux/writeback.h> 50 #include <linux/kobject.h> 51 #include <linux/seq_file.h> 52 #include <linux/mount.h> 53 #include "nilfs.h" 54 #include "export.h" 55 #include "mdt.h" 56 #include "alloc.h" 57 #include "btree.h" 58 #include "btnode.h" 59 #include "page.h" 60 #include "cpfile.h" 61 #include "ifile.h" 62 #include "dat.h" 63 #include "segment.h" 64 #include "segbuf.h" 65 66 MODULE_AUTHOR("NTT Corp."); 67 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem " 68 "(NILFS)"); 69 MODULE_LICENSE("GPL"); 70 71 static struct kmem_cache *nilfs_inode_cachep; 72 struct kmem_cache *nilfs_transaction_cachep; 73 struct kmem_cache *nilfs_segbuf_cachep; 74 struct kmem_cache *nilfs_btree_path_cache; 75 76 static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount); 77 static int nilfs_remount(struct super_block *sb, int *flags, char *data); 78 79 static void nilfs_set_error(struct nilfs_sb_info *sbi) 80 { 81 struct the_nilfs *nilfs = sbi->s_nilfs; 82 struct nilfs_super_block **sbp; 83 84 down_write(&nilfs->ns_sem); 85 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { 86 nilfs->ns_mount_state |= NILFS_ERROR_FS; 87 sbp = nilfs_prepare_super(sbi, 0); 88 if (likely(sbp)) { 89 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS); 90 if (sbp[1]) 91 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS); 92 nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL); 93 } 94 } 95 up_write(&nilfs->ns_sem); 96 } 97 98 /** 99 * nilfs_error() - report failure condition on a filesystem 100 * 101 * nilfs_error() sets an ERROR_FS flag on the superblock as well as 102 * reporting an error message. It should be called when NILFS detects 103 * incoherences or defects of meta data on disk. As for sustainable 104 * errors such as a single-shot I/O error, nilfs_warning() or the printk() 105 * function should be used instead. 106 * 107 * The segment constructor must not call this function because it can 108 * kill itself. 109 */ 110 void nilfs_error(struct super_block *sb, const char *function, 111 const char *fmt, ...) 112 { 113 struct nilfs_sb_info *sbi = NILFS_SB(sb); 114 va_list args; 115 116 va_start(args, fmt); 117 printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function); 118 vprintk(fmt, args); 119 printk("\n"); 120 va_end(args); 121 122 if (!(sb->s_flags & MS_RDONLY)) { 123 nilfs_set_error(sbi); 124 125 if (nilfs_test_opt(sbi, ERRORS_RO)) { 126 printk(KERN_CRIT "Remounting filesystem read-only\n"); 127 sb->s_flags |= MS_RDONLY; 128 } 129 } 130 131 if (nilfs_test_opt(sbi, ERRORS_PANIC)) 132 panic("NILFS (device %s): panic forced after error\n", 133 sb->s_id); 134 } 135 136 void nilfs_warning(struct super_block *sb, const char *function, 137 const char *fmt, ...) 138 { 139 va_list args; 140 141 va_start(args, fmt); 142 printk(KERN_WARNING "NILFS warning (device %s): %s: ", 143 sb->s_id, function); 144 vprintk(fmt, args); 145 printk("\n"); 146 va_end(args); 147 } 148 149 150 struct inode *nilfs_alloc_inode(struct super_block *sb) 151 { 152 struct nilfs_inode_info *ii; 153 154 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS); 155 if (!ii) 156 return NULL; 157 ii->i_bh = NULL; 158 ii->i_state = 0; 159 ii->i_cno = 0; 160 ii->vfs_inode.i_version = 1; 161 nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi); 162 return &ii->vfs_inode; 163 } 164 165 void nilfs_destroy_inode(struct inode *inode) 166 { 167 struct nilfs_mdt_info *mdi = NILFS_MDT(inode); 168 169 if (mdi) { 170 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */ 171 kfree(mdi); 172 } 173 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); 174 } 175 176 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag) 177 { 178 struct the_nilfs *nilfs = sbi->s_nilfs; 179 int err; 180 181 retry: 182 set_buffer_dirty(nilfs->ns_sbh[0]); 183 if (nilfs_test_opt(sbi, BARRIER)) { 184 err = __sync_dirty_buffer(nilfs->ns_sbh[0], 185 WRITE_SYNC | WRITE_FLUSH_FUA); 186 } else { 187 err = sync_dirty_buffer(nilfs->ns_sbh[0]); 188 } 189 190 if (unlikely(err)) { 191 printk(KERN_ERR 192 "NILFS: unable to write superblock (err=%d)\n", err); 193 if (err == -EIO && nilfs->ns_sbh[1]) { 194 /* 195 * sbp[0] points to newer log than sbp[1], 196 * so copy sbp[0] to sbp[1] to take over sbp[0]. 197 */ 198 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0], 199 nilfs->ns_sbsize); 200 nilfs_fall_back_super_block(nilfs); 201 goto retry; 202 } 203 } else { 204 struct nilfs_super_block *sbp = nilfs->ns_sbp[0]; 205 206 nilfs->ns_sbwcount++; 207 208 /* 209 * The latest segment becomes trailable from the position 210 * written in superblock. 211 */ 212 clear_nilfs_discontinued(nilfs); 213 214 /* update GC protection for recent segments */ 215 if (nilfs->ns_sbh[1]) { 216 if (flag == NILFS_SB_COMMIT_ALL) { 217 set_buffer_dirty(nilfs->ns_sbh[1]); 218 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0) 219 goto out; 220 } 221 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) < 222 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno)) 223 sbp = nilfs->ns_sbp[1]; 224 } 225 226 spin_lock(&nilfs->ns_last_segment_lock); 227 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq); 228 spin_unlock(&nilfs->ns_last_segment_lock); 229 } 230 out: 231 return err; 232 } 233 234 void nilfs_set_log_cursor(struct nilfs_super_block *sbp, 235 struct the_nilfs *nilfs) 236 { 237 sector_t nfreeblocks; 238 239 /* nilfs->ns_sem must be locked by the caller. */ 240 nilfs_count_free_blocks(nilfs, &nfreeblocks); 241 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks); 242 243 spin_lock(&nilfs->ns_last_segment_lock); 244 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); 245 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); 246 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); 247 spin_unlock(&nilfs->ns_last_segment_lock); 248 } 249 250 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi, 251 int flip) 252 { 253 struct the_nilfs *nilfs = sbi->s_nilfs; 254 struct nilfs_super_block **sbp = nilfs->ns_sbp; 255 256 /* nilfs->ns_sem must be locked by the caller. */ 257 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { 258 if (sbp[1] && 259 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) { 260 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 261 } else { 262 printk(KERN_CRIT "NILFS: superblock broke on dev %s\n", 263 sbi->s_super->s_id); 264 return NULL; 265 } 266 } else if (sbp[1] && 267 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { 268 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); 269 } 270 271 if (flip && sbp[1]) 272 nilfs_swap_super_block(nilfs); 273 274 return sbp; 275 } 276 277 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag) 278 { 279 struct the_nilfs *nilfs = sbi->s_nilfs; 280 struct nilfs_super_block **sbp = nilfs->ns_sbp; 281 time_t t; 282 283 /* nilfs->ns_sem must be locked by the caller. */ 284 t = get_seconds(); 285 nilfs->ns_sbwtime = t; 286 sbp[0]->s_wtime = cpu_to_le64(t); 287 sbp[0]->s_sum = 0; 288 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, 289 (unsigned char *)sbp[0], 290 nilfs->ns_sbsize)); 291 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) { 292 sbp[1]->s_wtime = sbp[0]->s_wtime; 293 sbp[1]->s_sum = 0; 294 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, 295 (unsigned char *)sbp[1], 296 nilfs->ns_sbsize)); 297 } 298 clear_nilfs_sb_dirty(nilfs); 299 return nilfs_sync_super(sbi, flag); 300 } 301 302 /** 303 * nilfs_cleanup_super() - write filesystem state for cleanup 304 * @sbi: nilfs_sb_info to be unmounted or degraded to read-only 305 * 306 * This function restores state flags in the on-disk super block. 307 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the 308 * filesystem was not clean previously. 309 */ 310 int nilfs_cleanup_super(struct nilfs_sb_info *sbi) 311 { 312 struct nilfs_super_block **sbp; 313 int flag = NILFS_SB_COMMIT; 314 int ret = -EIO; 315 316 sbp = nilfs_prepare_super(sbi, 0); 317 if (sbp) { 318 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state); 319 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs); 320 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) { 321 /* 322 * make the "clean" flag also to the opposite 323 * super block if both super blocks point to 324 * the same checkpoint. 325 */ 326 sbp[1]->s_state = sbp[0]->s_state; 327 flag = NILFS_SB_COMMIT_ALL; 328 } 329 ret = nilfs_commit_super(sbi, flag); 330 } 331 return ret; 332 } 333 334 static void nilfs_put_super(struct super_block *sb) 335 { 336 struct nilfs_sb_info *sbi = NILFS_SB(sb); 337 struct the_nilfs *nilfs = sbi->s_nilfs; 338 339 nilfs_detach_segment_constructor(sbi); 340 341 if (!(sb->s_flags & MS_RDONLY)) { 342 down_write(&nilfs->ns_sem); 343 nilfs_cleanup_super(sbi); 344 up_write(&nilfs->ns_sem); 345 } 346 347 iput(nilfs->ns_sufile); 348 iput(nilfs->ns_cpfile); 349 iput(nilfs->ns_dat); 350 351 destroy_nilfs(nilfs); 352 sbi->s_super = NULL; 353 sb->s_fs_info = NULL; 354 kfree(sbi); 355 } 356 357 static int nilfs_sync_fs(struct super_block *sb, int wait) 358 { 359 struct nilfs_sb_info *sbi = NILFS_SB(sb); 360 struct the_nilfs *nilfs = sbi->s_nilfs; 361 struct nilfs_super_block **sbp; 362 int err = 0; 363 364 /* This function is called when super block should be written back */ 365 if (wait) 366 err = nilfs_construct_segment(sb); 367 368 down_write(&nilfs->ns_sem); 369 if (nilfs_sb_dirty(nilfs)) { 370 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs)); 371 if (likely(sbp)) { 372 nilfs_set_log_cursor(sbp[0], nilfs); 373 nilfs_commit_super(sbi, NILFS_SB_COMMIT); 374 } 375 } 376 up_write(&nilfs->ns_sem); 377 378 return err; 379 } 380 381 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt, 382 struct nilfs_root **rootp) 383 { 384 struct the_nilfs *nilfs = sbi->s_nilfs; 385 struct nilfs_root *root; 386 struct nilfs_checkpoint *raw_cp; 387 struct buffer_head *bh_cp; 388 int err = -ENOMEM; 389 390 root = nilfs_find_or_create_root( 391 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno); 392 if (!root) 393 return err; 394 395 if (root->ifile) 396 goto reuse; /* already attached checkpoint */ 397 398 down_read(&nilfs->ns_segctor_sem); 399 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, 400 &bh_cp); 401 up_read(&nilfs->ns_segctor_sem); 402 if (unlikely(err)) { 403 if (err == -ENOENT || err == -EINVAL) { 404 printk(KERN_ERR 405 "NILFS: Invalid checkpoint " 406 "(checkpoint number=%llu)\n", 407 (unsigned long long)cno); 408 err = -EINVAL; 409 } 410 goto failed; 411 } 412 413 err = nilfs_ifile_read(sbi->s_super, root, nilfs->ns_inode_size, 414 &raw_cp->cp_ifile_inode, &root->ifile); 415 if (err) 416 goto failed_bh; 417 418 atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count)); 419 atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count)); 420 421 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); 422 423 reuse: 424 *rootp = root; 425 return 0; 426 427 failed_bh: 428 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); 429 failed: 430 nilfs_put_root(root); 431 432 return err; 433 } 434 435 static int nilfs_freeze(struct super_block *sb) 436 { 437 struct nilfs_sb_info *sbi = NILFS_SB(sb); 438 struct the_nilfs *nilfs = sbi->s_nilfs; 439 int err; 440 441 if (sb->s_flags & MS_RDONLY) 442 return 0; 443 444 /* Mark super block clean */ 445 down_write(&nilfs->ns_sem); 446 err = nilfs_cleanup_super(sbi); 447 up_write(&nilfs->ns_sem); 448 return err; 449 } 450 451 static int nilfs_unfreeze(struct super_block *sb) 452 { 453 struct nilfs_sb_info *sbi = NILFS_SB(sb); 454 struct the_nilfs *nilfs = sbi->s_nilfs; 455 456 if (sb->s_flags & MS_RDONLY) 457 return 0; 458 459 down_write(&nilfs->ns_sem); 460 nilfs_setup_super(sbi, false); 461 up_write(&nilfs->ns_sem); 462 return 0; 463 } 464 465 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) 466 { 467 struct super_block *sb = dentry->d_sb; 468 struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root; 469 struct the_nilfs *nilfs = root->nilfs; 470 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 471 unsigned long long blocks; 472 unsigned long overhead; 473 unsigned long nrsvblocks; 474 sector_t nfreeblocks; 475 int err; 476 477 /* 478 * Compute all of the segment blocks 479 * 480 * The blocks before first segment and after last segment 481 * are excluded. 482 */ 483 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments 484 - nilfs->ns_first_data_block; 485 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; 486 487 /* 488 * Compute the overhead 489 * 490 * When distributing meta data blocks outside segment structure, 491 * We must count them as the overhead. 492 */ 493 overhead = 0; 494 495 err = nilfs_count_free_blocks(nilfs, &nfreeblocks); 496 if (unlikely(err)) 497 return err; 498 499 buf->f_type = NILFS_SUPER_MAGIC; 500 buf->f_bsize = sb->s_blocksize; 501 buf->f_blocks = blocks - overhead; 502 buf->f_bfree = nfreeblocks; 503 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? 504 (buf->f_bfree - nrsvblocks) : 0; 505 buf->f_files = atomic_read(&root->inodes_count); 506 buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */ 507 buf->f_namelen = NILFS_NAME_LEN; 508 buf->f_fsid.val[0] = (u32)id; 509 buf->f_fsid.val[1] = (u32)(id >> 32); 510 511 return 0; 512 } 513 514 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs) 515 { 516 struct super_block *sb = vfs->mnt_sb; 517 struct nilfs_sb_info *sbi = NILFS_SB(sb); 518 struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root; 519 520 if (!nilfs_test_opt(sbi, BARRIER)) 521 seq_puts(seq, ",nobarrier"); 522 if (root->cno != NILFS_CPTREE_CURRENT_CNO) 523 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno); 524 if (nilfs_test_opt(sbi, ERRORS_PANIC)) 525 seq_puts(seq, ",errors=panic"); 526 if (nilfs_test_opt(sbi, ERRORS_CONT)) 527 seq_puts(seq, ",errors=continue"); 528 if (nilfs_test_opt(sbi, STRICT_ORDER)) 529 seq_puts(seq, ",order=strict"); 530 if (nilfs_test_opt(sbi, NORECOVERY)) 531 seq_puts(seq, ",norecovery"); 532 if (nilfs_test_opt(sbi, DISCARD)) 533 seq_puts(seq, ",discard"); 534 535 return 0; 536 } 537 538 static const struct super_operations nilfs_sops = { 539 .alloc_inode = nilfs_alloc_inode, 540 .destroy_inode = nilfs_destroy_inode, 541 .dirty_inode = nilfs_dirty_inode, 542 /* .write_inode = nilfs_write_inode, */ 543 /* .put_inode = nilfs_put_inode, */ 544 /* .drop_inode = nilfs_drop_inode, */ 545 .evict_inode = nilfs_evict_inode, 546 .put_super = nilfs_put_super, 547 /* .write_super = nilfs_write_super, */ 548 .sync_fs = nilfs_sync_fs, 549 .freeze_fs = nilfs_freeze, 550 .unfreeze_fs = nilfs_unfreeze, 551 /* .write_super_lockfs */ 552 /* .unlockfs */ 553 .statfs = nilfs_statfs, 554 .remount_fs = nilfs_remount, 555 /* .umount_begin */ 556 .show_options = nilfs_show_options 557 }; 558 559 enum { 560 Opt_err_cont, Opt_err_panic, Opt_err_ro, 561 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery, 562 Opt_discard, Opt_nodiscard, Opt_err, 563 }; 564 565 static match_table_t tokens = { 566 {Opt_err_cont, "errors=continue"}, 567 {Opt_err_panic, "errors=panic"}, 568 {Opt_err_ro, "errors=remount-ro"}, 569 {Opt_barrier, "barrier"}, 570 {Opt_nobarrier, "nobarrier"}, 571 {Opt_snapshot, "cp=%u"}, 572 {Opt_order, "order=%s"}, 573 {Opt_norecovery, "norecovery"}, 574 {Opt_discard, "discard"}, 575 {Opt_nodiscard, "nodiscard"}, 576 {Opt_err, NULL} 577 }; 578 579 static int parse_options(char *options, struct super_block *sb, int is_remount) 580 { 581 struct nilfs_sb_info *sbi = NILFS_SB(sb); 582 char *p; 583 substring_t args[MAX_OPT_ARGS]; 584 585 if (!options) 586 return 1; 587 588 while ((p = strsep(&options, ",")) != NULL) { 589 int token; 590 if (!*p) 591 continue; 592 593 token = match_token(p, tokens, args); 594 switch (token) { 595 case Opt_barrier: 596 nilfs_set_opt(sbi, BARRIER); 597 break; 598 case Opt_nobarrier: 599 nilfs_clear_opt(sbi, BARRIER); 600 break; 601 case Opt_order: 602 if (strcmp(args[0].from, "relaxed") == 0) 603 /* Ordered data semantics */ 604 nilfs_clear_opt(sbi, STRICT_ORDER); 605 else if (strcmp(args[0].from, "strict") == 0) 606 /* Strict in-order semantics */ 607 nilfs_set_opt(sbi, STRICT_ORDER); 608 else 609 return 0; 610 break; 611 case Opt_err_panic: 612 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC); 613 break; 614 case Opt_err_ro: 615 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO); 616 break; 617 case Opt_err_cont: 618 nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT); 619 break; 620 case Opt_snapshot: 621 if (is_remount) { 622 printk(KERN_ERR 623 "NILFS: \"%s\" option is invalid " 624 "for remount.\n", p); 625 return 0; 626 } 627 break; 628 case Opt_norecovery: 629 nilfs_set_opt(sbi, NORECOVERY); 630 break; 631 case Opt_discard: 632 nilfs_set_opt(sbi, DISCARD); 633 break; 634 case Opt_nodiscard: 635 nilfs_clear_opt(sbi, DISCARD); 636 break; 637 default: 638 printk(KERN_ERR 639 "NILFS: Unrecognized mount option \"%s\"\n", p); 640 return 0; 641 } 642 } 643 return 1; 644 } 645 646 static inline void 647 nilfs_set_default_options(struct nilfs_sb_info *sbi, 648 struct nilfs_super_block *sbp) 649 { 650 sbi->s_mount_opt = 651 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER; 652 } 653 654 static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount) 655 { 656 struct the_nilfs *nilfs = sbi->s_nilfs; 657 struct nilfs_super_block **sbp; 658 int max_mnt_count; 659 int mnt_count; 660 661 /* nilfs->ns_sem must be locked by the caller. */ 662 sbp = nilfs_prepare_super(sbi, 0); 663 if (!sbp) 664 return -EIO; 665 666 if (!is_mount) 667 goto skip_mount_setup; 668 669 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count); 670 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count); 671 672 if (nilfs->ns_mount_state & NILFS_ERROR_FS) { 673 printk(KERN_WARNING 674 "NILFS warning: mounting fs with errors\n"); 675 #if 0 676 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { 677 printk(KERN_WARNING 678 "NILFS warning: maximal mount count reached\n"); 679 #endif 680 } 681 if (!max_mnt_count) 682 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); 683 684 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1); 685 sbp[0]->s_mtime = cpu_to_le64(get_seconds()); 686 687 skip_mount_setup: 688 sbp[0]->s_state = 689 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS); 690 /* synchronize sbp[1] with sbp[0] */ 691 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); 692 return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL); 693 } 694 695 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb, 696 u64 pos, int blocksize, 697 struct buffer_head **pbh) 698 { 699 unsigned long long sb_index = pos; 700 unsigned long offset; 701 702 offset = do_div(sb_index, blocksize); 703 *pbh = sb_bread(sb, sb_index); 704 if (!*pbh) 705 return NULL; 706 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); 707 } 708 709 int nilfs_store_magic_and_option(struct super_block *sb, 710 struct nilfs_super_block *sbp, 711 char *data) 712 { 713 struct nilfs_sb_info *sbi = NILFS_SB(sb); 714 715 sb->s_magic = le16_to_cpu(sbp->s_magic); 716 717 /* FS independent flags */ 718 #ifdef NILFS_ATIME_DISABLE 719 sb->s_flags |= MS_NOATIME; 720 #endif 721 722 nilfs_set_default_options(sbi, sbp); 723 724 sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid); 725 sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid); 726 sbi->s_interval = le32_to_cpu(sbp->s_c_interval); 727 sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max); 728 729 return !parse_options(data, sb, 0) ? -EINVAL : 0 ; 730 } 731 732 int nilfs_check_feature_compatibility(struct super_block *sb, 733 struct nilfs_super_block *sbp) 734 { 735 __u64 features; 736 737 features = le64_to_cpu(sbp->s_feature_incompat) & 738 ~NILFS_FEATURE_INCOMPAT_SUPP; 739 if (features) { 740 printk(KERN_ERR "NILFS: couldn't mount because of unsupported " 741 "optional features (%llx)\n", 742 (unsigned long long)features); 743 return -EINVAL; 744 } 745 features = le64_to_cpu(sbp->s_feature_compat_ro) & 746 ~NILFS_FEATURE_COMPAT_RO_SUPP; 747 if (!(sb->s_flags & MS_RDONLY) && features) { 748 printk(KERN_ERR "NILFS: couldn't mount RDWR because of " 749 "unsupported optional features (%llx)\n", 750 (unsigned long long)features); 751 return -EINVAL; 752 } 753 return 0; 754 } 755 756 static int nilfs_get_root_dentry(struct super_block *sb, 757 struct nilfs_root *root, 758 struct dentry **root_dentry) 759 { 760 struct inode *inode; 761 struct dentry *dentry; 762 int ret = 0; 763 764 inode = nilfs_iget(sb, root, NILFS_ROOT_INO); 765 if (IS_ERR(inode)) { 766 printk(KERN_ERR "NILFS: get root inode failed\n"); 767 ret = PTR_ERR(inode); 768 goto out; 769 } 770 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) { 771 iput(inode); 772 printk(KERN_ERR "NILFS: corrupt root inode.\n"); 773 ret = -EINVAL; 774 goto out; 775 } 776 777 if (root->cno == NILFS_CPTREE_CURRENT_CNO) { 778 dentry = d_find_alias(inode); 779 if (!dentry) { 780 dentry = d_alloc_root(inode); 781 if (!dentry) { 782 iput(inode); 783 ret = -ENOMEM; 784 goto failed_dentry; 785 } 786 } else { 787 iput(inode); 788 } 789 } else { 790 dentry = d_obtain_alias(inode); 791 if (IS_ERR(dentry)) { 792 ret = PTR_ERR(dentry); 793 goto failed_dentry; 794 } 795 } 796 *root_dentry = dentry; 797 out: 798 return ret; 799 800 failed_dentry: 801 printk(KERN_ERR "NILFS: get root dentry failed\n"); 802 goto out; 803 } 804 805 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno, 806 struct dentry **root_dentry) 807 { 808 struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs; 809 struct nilfs_root *root; 810 int ret; 811 812 down_read(&nilfs->ns_segctor_sem); 813 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno); 814 up_read(&nilfs->ns_segctor_sem); 815 if (ret < 0) { 816 ret = (ret == -ENOENT) ? -EINVAL : ret; 817 goto out; 818 } else if (!ret) { 819 printk(KERN_ERR "NILFS: The specified checkpoint is " 820 "not a snapshot (checkpoint number=%llu).\n", 821 (unsigned long long)cno); 822 ret = -EINVAL; 823 goto out; 824 } 825 826 ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root); 827 if (ret) { 828 printk(KERN_ERR "NILFS: error loading snapshot " 829 "(checkpoint number=%llu).\n", 830 (unsigned long long)cno); 831 goto out; 832 } 833 ret = nilfs_get_root_dentry(s, root, root_dentry); 834 nilfs_put_root(root); 835 out: 836 return ret; 837 } 838 839 static int nilfs_tree_was_touched(struct dentry *root_dentry) 840 { 841 return atomic_read(&root_dentry->d_count) > 1; 842 } 843 844 /** 845 * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint 846 * @root_dentry: root dentry of the tree to be shrunk 847 * 848 * This function returns true if the tree was in-use. 849 */ 850 static int nilfs_try_to_shrink_tree(struct dentry *root_dentry) 851 { 852 if (have_submounts(root_dentry)) 853 return true; 854 shrink_dcache_parent(root_dentry); 855 return nilfs_tree_was_touched(root_dentry); 856 } 857 858 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno) 859 { 860 struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs; 861 struct nilfs_root *root; 862 struct inode *inode; 863 struct dentry *dentry; 864 int ret; 865 866 if (cno < 0 || cno > nilfs->ns_cno) 867 return false; 868 869 if (cno >= nilfs_last_cno(nilfs)) 870 return true; /* protect recent checkpoints */ 871 872 ret = false; 873 root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno); 874 if (root) { 875 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO); 876 if (inode) { 877 dentry = d_find_alias(inode); 878 if (dentry) { 879 if (nilfs_tree_was_touched(dentry)) 880 ret = nilfs_try_to_shrink_tree(dentry); 881 dput(dentry); 882 } 883 iput(inode); 884 } 885 nilfs_put_root(root); 886 } 887 return ret; 888 } 889 890 /** 891 * nilfs_fill_super() - initialize a super block instance 892 * @sb: super_block 893 * @data: mount options 894 * @silent: silent mode flag 895 * 896 * This function is called exclusively by nilfs->ns_mount_mutex. 897 * So, the recovery process is protected from other simultaneous mounts. 898 */ 899 static int 900 nilfs_fill_super(struct super_block *sb, void *data, int silent) 901 { 902 struct the_nilfs *nilfs; 903 struct nilfs_sb_info *sbi; 904 struct nilfs_root *fsroot; 905 struct backing_dev_info *bdi; 906 __u64 cno; 907 int err; 908 909 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 910 if (!sbi) 911 return -ENOMEM; 912 913 sb->s_fs_info = sbi; 914 sbi->s_super = sb; 915 916 nilfs = alloc_nilfs(sb->s_bdev); 917 if (!nilfs) { 918 err = -ENOMEM; 919 goto failed_sbi; 920 } 921 sbi->s_nilfs = nilfs; 922 923 err = init_nilfs(nilfs, sbi, (char *)data); 924 if (err) 925 goto failed_nilfs; 926 927 spin_lock_init(&sbi->s_inode_lock); 928 INIT_LIST_HEAD(&sbi->s_dirty_files); 929 930 /* 931 * Following initialization is overlapped because 932 * nilfs_sb_info structure has been cleared at the beginning. 933 * But we reserve them to keep our interest and make ready 934 * for the future change. 935 */ 936 get_random_bytes(&sbi->s_next_generation, 937 sizeof(sbi->s_next_generation)); 938 spin_lock_init(&sbi->s_next_gen_lock); 939 940 sb->s_op = &nilfs_sops; 941 sb->s_export_op = &nilfs_export_ops; 942 sb->s_root = NULL; 943 sb->s_time_gran = 1; 944 945 bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; 946 sb->s_bdi = bdi ? : &default_backing_dev_info; 947 948 err = load_nilfs(nilfs, sbi); 949 if (err) 950 goto failed_nilfs; 951 952 cno = nilfs_last_cno(nilfs); 953 err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot); 954 if (err) { 955 printk(KERN_ERR "NILFS: error loading last checkpoint " 956 "(checkpoint number=%llu).\n", (unsigned long long)cno); 957 goto failed_unload; 958 } 959 960 if (!(sb->s_flags & MS_RDONLY)) { 961 err = nilfs_attach_segment_constructor(sbi, fsroot); 962 if (err) 963 goto failed_checkpoint; 964 } 965 966 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root); 967 if (err) 968 goto failed_segctor; 969 970 nilfs_put_root(fsroot); 971 972 if (!(sb->s_flags & MS_RDONLY)) { 973 down_write(&nilfs->ns_sem); 974 nilfs_setup_super(sbi, true); 975 up_write(&nilfs->ns_sem); 976 } 977 978 return 0; 979 980 failed_segctor: 981 nilfs_detach_segment_constructor(sbi); 982 983 failed_checkpoint: 984 nilfs_put_root(fsroot); 985 986 failed_unload: 987 iput(nilfs->ns_sufile); 988 iput(nilfs->ns_cpfile); 989 iput(nilfs->ns_dat); 990 991 failed_nilfs: 992 destroy_nilfs(nilfs); 993 994 failed_sbi: 995 sb->s_fs_info = NULL; 996 kfree(sbi); 997 return err; 998 } 999 1000 static int nilfs_remount(struct super_block *sb, int *flags, char *data) 1001 { 1002 struct nilfs_sb_info *sbi = NILFS_SB(sb); 1003 struct the_nilfs *nilfs = sbi->s_nilfs; 1004 unsigned long old_sb_flags; 1005 struct nilfs_mount_options old_opts; 1006 int err; 1007 1008 old_sb_flags = sb->s_flags; 1009 old_opts.mount_opt = sbi->s_mount_opt; 1010 1011 if (!parse_options(data, sb, 1)) { 1012 err = -EINVAL; 1013 goto restore_opts; 1014 } 1015 sb->s_flags = (sb->s_flags & ~MS_POSIXACL); 1016 1017 err = -EINVAL; 1018 1019 if (!nilfs_valid_fs(nilfs)) { 1020 printk(KERN_WARNING "NILFS (device %s): couldn't " 1021 "remount because the filesystem is in an " 1022 "incomplete recovery state.\n", sb->s_id); 1023 goto restore_opts; 1024 } 1025 1026 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1027 goto out; 1028 if (*flags & MS_RDONLY) { 1029 /* Shutting down the segment constructor */ 1030 nilfs_detach_segment_constructor(sbi); 1031 sb->s_flags |= MS_RDONLY; 1032 1033 /* 1034 * Remounting a valid RW partition RDONLY, so set 1035 * the RDONLY flag and then mark the partition as valid again. 1036 */ 1037 down_write(&nilfs->ns_sem); 1038 nilfs_cleanup_super(sbi); 1039 up_write(&nilfs->ns_sem); 1040 } else { 1041 __u64 features; 1042 struct nilfs_root *root; 1043 1044 /* 1045 * Mounting a RDONLY partition read-write, so reread and 1046 * store the current valid flag. (It may have been changed 1047 * by fsck since we originally mounted the partition.) 1048 */ 1049 down_read(&nilfs->ns_sem); 1050 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 1051 ~NILFS_FEATURE_COMPAT_RO_SUPP; 1052 up_read(&nilfs->ns_sem); 1053 if (features) { 1054 printk(KERN_WARNING "NILFS (device %s): couldn't " 1055 "remount RDWR because of unsupported optional " 1056 "features (%llx)\n", 1057 sb->s_id, (unsigned long long)features); 1058 err = -EROFS; 1059 goto restore_opts; 1060 } 1061 1062 sb->s_flags &= ~MS_RDONLY; 1063 1064 root = NILFS_I(sb->s_root->d_inode)->i_root; 1065 err = nilfs_attach_segment_constructor(sbi, root); 1066 if (err) 1067 goto restore_opts; 1068 1069 down_write(&nilfs->ns_sem); 1070 nilfs_setup_super(sbi, true); 1071 up_write(&nilfs->ns_sem); 1072 } 1073 out: 1074 return 0; 1075 1076 restore_opts: 1077 sb->s_flags = old_sb_flags; 1078 sbi->s_mount_opt = old_opts.mount_opt; 1079 return err; 1080 } 1081 1082 struct nilfs_super_data { 1083 struct block_device *bdev; 1084 struct nilfs_sb_info *sbi; 1085 __u64 cno; 1086 int flags; 1087 }; 1088 1089 /** 1090 * nilfs_identify - pre-read mount options needed to identify mount instance 1091 * @data: mount options 1092 * @sd: nilfs_super_data 1093 */ 1094 static int nilfs_identify(char *data, struct nilfs_super_data *sd) 1095 { 1096 char *p, *options = data; 1097 substring_t args[MAX_OPT_ARGS]; 1098 int token; 1099 int ret = 0; 1100 1101 do { 1102 p = strsep(&options, ","); 1103 if (p != NULL && *p) { 1104 token = match_token(p, tokens, args); 1105 if (token == Opt_snapshot) { 1106 if (!(sd->flags & MS_RDONLY)) { 1107 ret++; 1108 } else { 1109 sd->cno = simple_strtoull(args[0].from, 1110 NULL, 0); 1111 /* 1112 * No need to see the end pointer; 1113 * match_token() has done syntax 1114 * checking. 1115 */ 1116 if (sd->cno == 0) 1117 ret++; 1118 } 1119 } 1120 if (ret) 1121 printk(KERN_ERR 1122 "NILFS: invalid mount option: %s\n", p); 1123 } 1124 if (!options) 1125 break; 1126 BUG_ON(options == data); 1127 *(options - 1) = ','; 1128 } while (!ret); 1129 return ret; 1130 } 1131 1132 static int nilfs_set_bdev_super(struct super_block *s, void *data) 1133 { 1134 s->s_bdev = data; 1135 s->s_dev = s->s_bdev->bd_dev; 1136 return 0; 1137 } 1138 1139 static int nilfs_test_bdev_super(struct super_block *s, void *data) 1140 { 1141 return (void *)s->s_bdev == data; 1142 } 1143 1144 static struct dentry * 1145 nilfs_mount(struct file_system_type *fs_type, int flags, 1146 const char *dev_name, void *data) 1147 { 1148 struct nilfs_super_data sd; 1149 struct super_block *s; 1150 fmode_t mode = FMODE_READ; 1151 struct dentry *root_dentry; 1152 int err, s_new = false; 1153 1154 if (!(flags & MS_RDONLY)) 1155 mode |= FMODE_WRITE; 1156 1157 sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type); 1158 if (IS_ERR(sd.bdev)) 1159 return ERR_CAST(sd.bdev); 1160 1161 sd.cno = 0; 1162 sd.flags = flags; 1163 if (nilfs_identify((char *)data, &sd)) { 1164 err = -EINVAL; 1165 goto failed; 1166 } 1167 1168 /* 1169 * once the super is inserted into the list by sget, s_umount 1170 * will protect the lockfs code from trying to start a snapshot 1171 * while we are mounting 1172 */ 1173 mutex_lock(&sd.bdev->bd_fsfreeze_mutex); 1174 if (sd.bdev->bd_fsfreeze_count > 0) { 1175 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); 1176 err = -EBUSY; 1177 goto failed; 1178 } 1179 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev); 1180 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); 1181 if (IS_ERR(s)) { 1182 err = PTR_ERR(s); 1183 goto failed; 1184 } 1185 1186 if (!s->s_root) { 1187 char b[BDEVNAME_SIZE]; 1188 1189 s_new = true; 1190 1191 /* New superblock instance created */ 1192 s->s_flags = flags; 1193 s->s_mode = mode; 1194 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); 1195 sb_set_blocksize(s, block_size(sd.bdev)); 1196 1197 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0); 1198 if (err) 1199 goto failed_super; 1200 1201 s->s_flags |= MS_ACTIVE; 1202 } else if (!sd.cno) { 1203 int busy = false; 1204 1205 if (nilfs_tree_was_touched(s->s_root)) { 1206 busy = nilfs_try_to_shrink_tree(s->s_root); 1207 if (busy && (flags ^ s->s_flags) & MS_RDONLY) { 1208 printk(KERN_ERR "NILFS: the device already " 1209 "has a %s mount.\n", 1210 (s->s_flags & MS_RDONLY) ? 1211 "read-only" : "read/write"); 1212 err = -EBUSY; 1213 goto failed_super; 1214 } 1215 } 1216 if (!busy) { 1217 /* 1218 * Try remount to setup mount states if the current 1219 * tree is not mounted and only snapshots use this sb. 1220 */ 1221 err = nilfs_remount(s, &flags, data); 1222 if (err) 1223 goto failed_super; 1224 } 1225 } 1226 1227 if (sd.cno) { 1228 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry); 1229 if (err) 1230 goto failed_super; 1231 } else { 1232 root_dentry = dget(s->s_root); 1233 } 1234 1235 if (!s_new) 1236 close_bdev_exclusive(sd.bdev, mode); 1237 1238 return root_dentry; 1239 1240 failed_super: 1241 deactivate_locked_super(s); 1242 1243 failed: 1244 if (!s_new) 1245 close_bdev_exclusive(sd.bdev, mode); 1246 return ERR_PTR(err); 1247 } 1248 1249 struct file_system_type nilfs_fs_type = { 1250 .owner = THIS_MODULE, 1251 .name = "nilfs2", 1252 .mount = nilfs_mount, 1253 .kill_sb = kill_block_super, 1254 .fs_flags = FS_REQUIRES_DEV, 1255 }; 1256 1257 static void nilfs_inode_init_once(void *obj) 1258 { 1259 struct nilfs_inode_info *ii = obj; 1260 1261 INIT_LIST_HEAD(&ii->i_dirty); 1262 #ifdef CONFIG_NILFS_XATTR 1263 init_rwsem(&ii->xattr_sem); 1264 #endif 1265 nilfs_btnode_cache_init_once(&ii->i_btnode_cache); 1266 ii->i_bmap = &ii->i_bmap_data; 1267 inode_init_once(&ii->vfs_inode); 1268 } 1269 1270 static void nilfs_segbuf_init_once(void *obj) 1271 { 1272 memset(obj, 0, sizeof(struct nilfs_segment_buffer)); 1273 } 1274 1275 static void nilfs_destroy_cachep(void) 1276 { 1277 if (nilfs_inode_cachep) 1278 kmem_cache_destroy(nilfs_inode_cachep); 1279 if (nilfs_transaction_cachep) 1280 kmem_cache_destroy(nilfs_transaction_cachep); 1281 if (nilfs_segbuf_cachep) 1282 kmem_cache_destroy(nilfs_segbuf_cachep); 1283 if (nilfs_btree_path_cache) 1284 kmem_cache_destroy(nilfs_btree_path_cache); 1285 } 1286 1287 static int __init nilfs_init_cachep(void) 1288 { 1289 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", 1290 sizeof(struct nilfs_inode_info), 0, 1291 SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once); 1292 if (!nilfs_inode_cachep) 1293 goto fail; 1294 1295 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache", 1296 sizeof(struct nilfs_transaction_info), 0, 1297 SLAB_RECLAIM_ACCOUNT, NULL); 1298 if (!nilfs_transaction_cachep) 1299 goto fail; 1300 1301 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache", 1302 sizeof(struct nilfs_segment_buffer), 0, 1303 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once); 1304 if (!nilfs_segbuf_cachep) 1305 goto fail; 1306 1307 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache", 1308 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX, 1309 0, 0, NULL); 1310 if (!nilfs_btree_path_cache) 1311 goto fail; 1312 1313 return 0; 1314 1315 fail: 1316 nilfs_destroy_cachep(); 1317 return -ENOMEM; 1318 } 1319 1320 static int __init init_nilfs_fs(void) 1321 { 1322 int err; 1323 1324 err = nilfs_init_cachep(); 1325 if (err) 1326 goto fail; 1327 1328 err = register_filesystem(&nilfs_fs_type); 1329 if (err) 1330 goto free_cachep; 1331 1332 printk(KERN_INFO "NILFS version 2 loaded\n"); 1333 return 0; 1334 1335 free_cachep: 1336 nilfs_destroy_cachep(); 1337 fail: 1338 return err; 1339 } 1340 1341 static void __exit exit_nilfs_fs(void) 1342 { 1343 nilfs_destroy_cachep(); 1344 unregister_filesystem(&nilfs_fs_type); 1345 } 1346 1347 module_init(init_nilfs_fs) 1348 module_exit(exit_nilfs_fs) 1349