Ryusuke Konishi | 783f618 | 2009-04-06 19:01:35 -0700 | [diff] [blame] | 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/smp_lock.h> |
| 49 | #include <linux/vfs.h> |
| 50 | #include <linux/writeback.h> |
| 51 | #include <linux/kobject.h> |
| 52 | #include <linux/exportfs.h> |
| 53 | #include "nilfs.h" |
| 54 | #include "mdt.h" |
| 55 | #include "alloc.h" |
| 56 | #include "page.h" |
| 57 | #include "cpfile.h" |
| 58 | #include "ifile.h" |
| 59 | #include "dat.h" |
| 60 | #include "segment.h" |
| 61 | #include "segbuf.h" |
| 62 | |
| 63 | MODULE_AUTHOR("NTT Corp."); |
| 64 | MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem " |
| 65 | "(NILFS)"); |
| 66 | MODULE_VERSION(NILFS_VERSION); |
| 67 | MODULE_LICENSE("GPL"); |
| 68 | |
| 69 | static int nilfs_remount(struct super_block *sb, int *flags, char *data); |
| 70 | static int test_exclusive_mount(struct file_system_type *fs_type, |
| 71 | struct block_device *bdev, int flags); |
| 72 | |
| 73 | /** |
| 74 | * nilfs_error() - report failure condition on a filesystem |
| 75 | * |
| 76 | * nilfs_error() sets an ERROR_FS flag on the superblock as well as |
| 77 | * reporting an error message. It should be called when NILFS detects |
| 78 | * incoherences or defects of meta data on disk. As for sustainable |
| 79 | * errors such as a single-shot I/O error, nilfs_warning() or the printk() |
| 80 | * function should be used instead. |
| 81 | * |
| 82 | * The segment constructor must not call this function because it can |
| 83 | * kill itself. |
| 84 | */ |
| 85 | void nilfs_error(struct super_block *sb, const char *function, |
| 86 | const char *fmt, ...) |
| 87 | { |
| 88 | struct nilfs_sb_info *sbi = NILFS_SB(sb); |
| 89 | va_list args; |
| 90 | |
| 91 | va_start(args, fmt); |
| 92 | printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function); |
| 93 | vprintk(fmt, args); |
| 94 | printk("\n"); |
| 95 | va_end(args); |
| 96 | |
| 97 | if (!(sb->s_flags & MS_RDONLY)) { |
| 98 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 99 | |
| 100 | if (!nilfs_test_opt(sbi, ERRORS_CONT)) |
| 101 | nilfs_detach_segment_constructor(sbi); |
| 102 | |
| 103 | down_write(&nilfs->ns_sem); |
| 104 | if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { |
| 105 | nilfs->ns_mount_state |= NILFS_ERROR_FS; |
| 106 | nilfs->ns_sbp->s_state |= cpu_to_le16(NILFS_ERROR_FS); |
| 107 | nilfs_commit_super(sbi); |
| 108 | } |
| 109 | up_write(&nilfs->ns_sem); |
| 110 | |
| 111 | if (nilfs_test_opt(sbi, ERRORS_RO)) { |
| 112 | printk(KERN_CRIT "Remounting filesystem read-only\n"); |
| 113 | sb->s_flags |= MS_RDONLY; |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | if (nilfs_test_opt(sbi, ERRORS_PANIC)) |
| 118 | panic("NILFS (device %s): panic forced after error\n", |
| 119 | sb->s_id); |
| 120 | } |
| 121 | |
| 122 | void nilfs_warning(struct super_block *sb, const char *function, |
| 123 | const char *fmt, ...) |
| 124 | { |
| 125 | va_list args; |
| 126 | |
| 127 | va_start(args, fmt); |
| 128 | printk(KERN_WARNING "NILFS warning (device %s): %s: ", |
| 129 | sb->s_id, function); |
| 130 | vprintk(fmt, args); |
| 131 | printk("\n"); |
| 132 | va_end(args); |
| 133 | } |
| 134 | |
| 135 | static struct kmem_cache *nilfs_inode_cachep; |
| 136 | |
| 137 | struct inode *nilfs_alloc_inode(struct super_block *sb) |
| 138 | { |
| 139 | struct nilfs_inode_info *ii; |
| 140 | |
| 141 | ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS); |
| 142 | if (!ii) |
| 143 | return NULL; |
| 144 | ii->i_bh = NULL; |
| 145 | ii->i_state = 0; |
| 146 | ii->vfs_inode.i_version = 1; |
| 147 | nilfs_btnode_cache_init(&ii->i_btnode_cache); |
| 148 | return &ii->vfs_inode; |
| 149 | } |
| 150 | |
| 151 | void nilfs_destroy_inode(struct inode *inode) |
| 152 | { |
| 153 | kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); |
| 154 | } |
| 155 | |
| 156 | static void init_once(void *obj) |
| 157 | { |
| 158 | struct nilfs_inode_info *ii = obj; |
| 159 | |
| 160 | INIT_LIST_HEAD(&ii->i_dirty); |
| 161 | #ifdef CONFIG_NILFS_XATTR |
| 162 | init_rwsem(&ii->xattr_sem); |
| 163 | #endif |
| 164 | nilfs_btnode_cache_init_once(&ii->i_btnode_cache); |
| 165 | ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union; |
| 166 | inode_init_once(&ii->vfs_inode); |
| 167 | } |
| 168 | |
| 169 | static int nilfs_init_inode_cache(void) |
| 170 | { |
| 171 | nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", |
| 172 | sizeof(struct nilfs_inode_info), |
| 173 | 0, SLAB_RECLAIM_ACCOUNT, |
| 174 | init_once); |
| 175 | |
| 176 | return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0; |
| 177 | } |
| 178 | |
| 179 | static inline void nilfs_destroy_inode_cache(void) |
| 180 | { |
| 181 | kmem_cache_destroy(nilfs_inode_cachep); |
| 182 | } |
| 183 | |
| 184 | static void nilfs_clear_inode(struct inode *inode) |
| 185 | { |
| 186 | struct nilfs_inode_info *ii = NILFS_I(inode); |
| 187 | struct nilfs_transaction_info ti; |
| 188 | struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb); |
| 189 | |
| 190 | #ifdef CONFIG_NILFS_POSIX_ACL |
| 191 | if (ii->i_acl && ii->i_acl != NILFS_ACL_NOT_CACHED) { |
| 192 | posix_acl_release(ii->i_acl); |
| 193 | ii->i_acl = NILFS_ACL_NOT_CACHED; |
| 194 | } |
| 195 | if (ii->i_default_acl && ii->i_default_acl != NILFS_ACL_NOT_CACHED) { |
| 196 | posix_acl_release(ii->i_default_acl); |
| 197 | ii->i_default_acl = NILFS_ACL_NOT_CACHED; |
| 198 | } |
| 199 | #endif |
| 200 | /* |
| 201 | * Free resources allocated in nilfs_read_inode(), here. |
| 202 | */ |
| 203 | nilfs_transaction_begin(inode->i_sb, &ti, 0); |
| 204 | |
| 205 | spin_lock(&sbi->s_inode_lock); |
| 206 | if (!list_empty(&ii->i_dirty)) |
| 207 | list_del_init(&ii->i_dirty); |
| 208 | brelse(ii->i_bh); |
| 209 | ii->i_bh = NULL; |
| 210 | spin_unlock(&sbi->s_inode_lock); |
| 211 | |
| 212 | if (test_bit(NILFS_I_BMAP, &ii->i_state)) |
| 213 | nilfs_bmap_clear(ii->i_bmap); |
| 214 | |
| 215 | nilfs_btnode_cache_clear(&ii->i_btnode_cache); |
| 216 | |
| 217 | nilfs_transaction_end(inode->i_sb, 0); |
| 218 | } |
| 219 | |
| 220 | /** |
| 221 | * nilfs_update_last_segment - change pointer to the latest segment |
| 222 | * @sbi: nilfs_sb_info |
| 223 | * @update_cno: flag whether to update checkpoint number. |
| 224 | * |
| 225 | * nilfs_update_last_segment() changes information in the super block |
| 226 | * after a partial segment is written out successfully. The super |
| 227 | * block is marked dirty. It will be written out at the next VFS sync |
| 228 | * operations such as sync_supers() and generic_shutdown_super(). |
| 229 | */ |
| 230 | void nilfs_update_last_segment(struct nilfs_sb_info *sbi, int update_cno) |
| 231 | { |
| 232 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 233 | struct nilfs_super_block *sbp = nilfs->ns_sbp; |
| 234 | |
| 235 | /* nilfs->sem must be locked by the caller. */ |
| 236 | spin_lock(&nilfs->ns_last_segment_lock); |
| 237 | if (update_cno) |
| 238 | nilfs->ns_last_cno = nilfs->ns_cno++; |
| 239 | sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); |
| 240 | sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); |
| 241 | sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); |
| 242 | spin_unlock(&nilfs->ns_last_segment_lock); |
| 243 | |
| 244 | sbi->s_super->s_dirt = 1; /* must be set if delaying the call of |
| 245 | nilfs_commit_super() */ |
| 246 | } |
| 247 | |
| 248 | static int nilfs_sync_super(struct nilfs_sb_info *sbi) |
| 249 | { |
| 250 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 251 | int err; |
| 252 | int barrier_done = 0; |
| 253 | |
| 254 | if (nilfs_test_opt(sbi, BARRIER)) { |
| 255 | set_buffer_ordered(nilfs->ns_sbh); |
| 256 | barrier_done = 1; |
| 257 | } |
| 258 | retry: |
| 259 | set_buffer_dirty(nilfs->ns_sbh); |
| 260 | err = sync_dirty_buffer(nilfs->ns_sbh); |
| 261 | if (err == -EOPNOTSUPP && barrier_done) { |
| 262 | nilfs_warning(sbi->s_super, __func__, |
| 263 | "barrier-based sync failed. " |
| 264 | "disabling barriers\n"); |
| 265 | nilfs_clear_opt(sbi, BARRIER); |
| 266 | barrier_done = 0; |
| 267 | clear_buffer_ordered(nilfs->ns_sbh); |
| 268 | goto retry; |
| 269 | } |
| 270 | if (unlikely(err)) |
| 271 | printk(KERN_ERR |
| 272 | "NILFS: unable to write superblock (err=%d)\n", err); |
| 273 | else { |
| 274 | nilfs_dispose_used_segments(nilfs); |
| 275 | clear_nilfs_discontinued(nilfs); |
| 276 | } |
| 277 | |
| 278 | return err; |
| 279 | } |
| 280 | |
| 281 | int nilfs_commit_super(struct nilfs_sb_info *sbi) |
| 282 | { |
| 283 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 284 | struct nilfs_super_block *sbp = nilfs->ns_sbp; |
| 285 | sector_t nfreeblocks; |
| 286 | int err; |
| 287 | |
| 288 | /* nilfs->sem must be locked by the caller. */ |
| 289 | err = nilfs_count_free_blocks(nilfs, &nfreeblocks); |
| 290 | if (unlikely(err)) { |
| 291 | printk(KERN_ERR "NILFS: failed to count free blocks\n"); |
| 292 | return err; |
| 293 | } |
| 294 | sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks); |
| 295 | sbp->s_wtime = cpu_to_le64(get_seconds()); |
| 296 | sbp->s_sum = 0; |
| 297 | sbp->s_sum = crc32_le(nilfs->ns_crc_seed, (unsigned char *)sbp, |
| 298 | le16_to_cpu(sbp->s_bytes)); |
| 299 | |
| 300 | sbi->s_super->s_dirt = 0; |
| 301 | return nilfs_sync_super(sbi); |
| 302 | } |
| 303 | |
| 304 | static void nilfs_put_super(struct super_block *sb) |
| 305 | { |
| 306 | struct nilfs_sb_info *sbi = NILFS_SB(sb); |
| 307 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 308 | |
| 309 | nilfs_detach_segment_constructor(sbi); |
| 310 | |
| 311 | if (!(sb->s_flags & MS_RDONLY)) { |
| 312 | down_write(&nilfs->ns_sem); |
| 313 | nilfs->ns_sbp->s_state = cpu_to_le16(nilfs->ns_mount_state); |
| 314 | nilfs_commit_super(sbi); |
| 315 | up_write(&nilfs->ns_sem); |
| 316 | } |
| 317 | |
| 318 | nilfs_detach_checkpoint(sbi); |
| 319 | put_nilfs(sbi->s_nilfs); |
| 320 | sbi->s_super = NULL; |
| 321 | sb->s_fs_info = NULL; |
| 322 | kfree(sbi); |
| 323 | } |
| 324 | |
| 325 | /** |
| 326 | * nilfs_write_super - write super block(s) of NILFS |
| 327 | * @sb: super_block |
| 328 | * |
| 329 | * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and |
| 330 | * clears s_dirt. This function is called in the section protected by |
| 331 | * lock_super(). |
| 332 | * |
| 333 | * The s_dirt flag is managed by each filesystem and we protect it by ns_sem |
| 334 | * of the struct the_nilfs. Lock order must be as follows: |
| 335 | * |
| 336 | * 1. lock_super() |
| 337 | * 2. down_write(&nilfs->ns_sem) |
| 338 | * |
| 339 | * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer |
| 340 | * of the super block (nilfs->ns_sbp). |
| 341 | * |
| 342 | * In most cases, VFS functions call lock_super() before calling these |
| 343 | * methods. So we must be careful not to bring on deadlocks when using |
| 344 | * lock_super(); see generic_shutdown_super(), write_super(), and so on. |
| 345 | * |
| 346 | * Note that order of lock_kernel() and lock_super() depends on contexts |
| 347 | * of VFS. We should also note that lock_kernel() can be used in its |
| 348 | * protective section and only the outermost one has an effect. |
| 349 | */ |
| 350 | static void nilfs_write_super(struct super_block *sb) |
| 351 | { |
| 352 | struct nilfs_sb_info *sbi = NILFS_SB(sb); |
| 353 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 354 | |
| 355 | down_write(&nilfs->ns_sem); |
| 356 | if (!(sb->s_flags & MS_RDONLY)) |
| 357 | nilfs_commit_super(sbi); |
| 358 | sb->s_dirt = 0; |
| 359 | up_write(&nilfs->ns_sem); |
| 360 | } |
| 361 | |
| 362 | static int nilfs_sync_fs(struct super_block *sb, int wait) |
| 363 | { |
| 364 | int err = 0; |
| 365 | |
| 366 | /* This function is called when super block should be written back */ |
| 367 | if (wait) |
| 368 | err = nilfs_construct_segment(sb); |
| 369 | return err; |
| 370 | } |
| 371 | |
| 372 | int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) |
| 373 | { |
| 374 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 375 | struct nilfs_checkpoint *raw_cp; |
| 376 | struct buffer_head *bh_cp; |
| 377 | int err; |
| 378 | |
| 379 | down_write(&nilfs->ns_sem); |
| 380 | list_add(&sbi->s_list, &nilfs->ns_supers); |
| 381 | up_write(&nilfs->ns_sem); |
| 382 | |
| 383 | sbi->s_ifile = nilfs_mdt_new( |
| 384 | nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP); |
| 385 | if (!sbi->s_ifile) |
| 386 | return -ENOMEM; |
| 387 | |
| 388 | err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size); |
| 389 | if (unlikely(err)) |
| 390 | goto failed; |
| 391 | |
| 392 | err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, |
| 393 | &bh_cp); |
| 394 | if (unlikely(err)) { |
| 395 | if (err == -ENOENT || err == -EINVAL) { |
| 396 | printk(KERN_ERR |
| 397 | "NILFS: Invalid checkpoint " |
| 398 | "(checkpoint number=%llu)\n", |
| 399 | (unsigned long long)cno); |
| 400 | err = -EINVAL; |
| 401 | } |
| 402 | goto failed; |
| 403 | } |
| 404 | err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode); |
| 405 | if (unlikely(err)) |
| 406 | goto failed_bh; |
| 407 | atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count)); |
| 408 | atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count)); |
| 409 | |
| 410 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); |
| 411 | return 0; |
| 412 | |
| 413 | failed_bh: |
| 414 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); |
| 415 | failed: |
| 416 | nilfs_mdt_destroy(sbi->s_ifile); |
| 417 | sbi->s_ifile = NULL; |
| 418 | |
| 419 | down_write(&nilfs->ns_sem); |
| 420 | list_del_init(&sbi->s_list); |
| 421 | up_write(&nilfs->ns_sem); |
| 422 | |
| 423 | return err; |
| 424 | } |
| 425 | |
| 426 | void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi) |
| 427 | { |
| 428 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 429 | |
| 430 | nilfs_mdt_clear(sbi->s_ifile); |
| 431 | nilfs_mdt_destroy(sbi->s_ifile); |
| 432 | sbi->s_ifile = NULL; |
| 433 | down_write(&nilfs->ns_sem); |
| 434 | list_del_init(&sbi->s_list); |
| 435 | up_write(&nilfs->ns_sem); |
| 436 | } |
| 437 | |
| 438 | static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi) |
| 439 | { |
| 440 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 441 | int err = 0; |
| 442 | |
| 443 | down_write(&nilfs->ns_sem); |
| 444 | if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) { |
| 445 | nilfs->ns_mount_state |= NILFS_VALID_FS; |
| 446 | err = nilfs_commit_super(sbi); |
| 447 | if (likely(!err)) |
| 448 | printk(KERN_INFO "NILFS: recovery complete.\n"); |
| 449 | } |
| 450 | up_write(&nilfs->ns_sem); |
| 451 | return err; |
| 452 | } |
| 453 | |
| 454 | static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 455 | { |
| 456 | struct super_block *sb = dentry->d_sb; |
| 457 | struct nilfs_sb_info *sbi = NILFS_SB(sb); |
| 458 | unsigned long long blocks; |
| 459 | unsigned long overhead; |
| 460 | unsigned long nrsvblocks; |
| 461 | sector_t nfreeblocks; |
| 462 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 463 | int err; |
| 464 | |
| 465 | /* |
| 466 | * Compute all of the segment blocks |
| 467 | * |
| 468 | * The blocks before first segment and after last segment |
| 469 | * are excluded. |
| 470 | */ |
| 471 | blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments |
| 472 | - nilfs->ns_first_data_block; |
| 473 | nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; |
| 474 | |
| 475 | /* |
| 476 | * Compute the overhead |
| 477 | * |
| 478 | * When distributing meta data blocks outside semgent structure, |
| 479 | * We must count them as the overhead. |
| 480 | */ |
| 481 | overhead = 0; |
| 482 | |
| 483 | err = nilfs_count_free_blocks(nilfs, &nfreeblocks); |
| 484 | if (unlikely(err)) |
| 485 | return err; |
| 486 | |
| 487 | buf->f_type = NILFS_SUPER_MAGIC; |
| 488 | buf->f_bsize = sb->s_blocksize; |
| 489 | buf->f_blocks = blocks - overhead; |
| 490 | buf->f_bfree = nfreeblocks; |
| 491 | buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? |
| 492 | (buf->f_bfree - nrsvblocks) : 0; |
| 493 | buf->f_files = atomic_read(&sbi->s_inodes_count); |
| 494 | buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */ |
| 495 | buf->f_namelen = NILFS_NAME_LEN; |
| 496 | return 0; |
| 497 | } |
| 498 | |
| 499 | static struct super_operations nilfs_sops = { |
| 500 | .alloc_inode = nilfs_alloc_inode, |
| 501 | .destroy_inode = nilfs_destroy_inode, |
| 502 | .dirty_inode = nilfs_dirty_inode, |
| 503 | /* .write_inode = nilfs_write_inode, */ |
| 504 | /* .put_inode = nilfs_put_inode, */ |
| 505 | /* .drop_inode = nilfs_drop_inode, */ |
| 506 | .delete_inode = nilfs_delete_inode, |
| 507 | .put_super = nilfs_put_super, |
| 508 | .write_super = nilfs_write_super, |
| 509 | .sync_fs = nilfs_sync_fs, |
| 510 | /* .write_super_lockfs */ |
| 511 | /* .unlockfs */ |
| 512 | .statfs = nilfs_statfs, |
| 513 | .remount_fs = nilfs_remount, |
| 514 | .clear_inode = nilfs_clear_inode, |
| 515 | /* .umount_begin */ |
| 516 | /* .show_options */ |
| 517 | }; |
| 518 | |
| 519 | static struct inode * |
| 520 | nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation) |
| 521 | { |
| 522 | struct inode *inode; |
| 523 | |
| 524 | if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO && |
| 525 | ino != NILFS_SKETCH_INO) |
| 526 | return ERR_PTR(-ESTALE); |
| 527 | |
| 528 | inode = nilfs_iget(sb, ino); |
| 529 | if (IS_ERR(inode)) |
| 530 | return ERR_CAST(inode); |
| 531 | if (generation && inode->i_generation != generation) { |
| 532 | iput(inode); |
| 533 | return ERR_PTR(-ESTALE); |
| 534 | } |
| 535 | |
| 536 | return inode; |
| 537 | } |
| 538 | |
| 539 | static struct dentry * |
| 540 | nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, |
| 541 | int fh_type) |
| 542 | { |
| 543 | return generic_fh_to_dentry(sb, fid, fh_len, fh_type, |
| 544 | nilfs_nfs_get_inode); |
| 545 | } |
| 546 | |
| 547 | static struct dentry * |
| 548 | nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, |
| 549 | int fh_type) |
| 550 | { |
| 551 | return generic_fh_to_parent(sb, fid, fh_len, fh_type, |
| 552 | nilfs_nfs_get_inode); |
| 553 | } |
| 554 | |
| 555 | static struct export_operations nilfs_export_ops = { |
| 556 | .fh_to_dentry = nilfs_fh_to_dentry, |
| 557 | .fh_to_parent = nilfs_fh_to_parent, |
| 558 | .get_parent = nilfs_get_parent, |
| 559 | }; |
| 560 | |
| 561 | enum { |
| 562 | Opt_err_cont, Opt_err_panic, Opt_err_ro, |
| 563 | Opt_barrier, Opt_snapshot, Opt_order, |
| 564 | Opt_err, |
| 565 | }; |
| 566 | |
| 567 | static match_table_t tokens = { |
| 568 | {Opt_err_cont, "errors=continue"}, |
| 569 | {Opt_err_panic, "errors=panic"}, |
| 570 | {Opt_err_ro, "errors=remount-ro"}, |
| 571 | {Opt_barrier, "barrier=%s"}, |
| 572 | {Opt_snapshot, "cp=%u"}, |
| 573 | {Opt_order, "order=%s"}, |
| 574 | {Opt_err, NULL} |
| 575 | }; |
| 576 | |
| 577 | static int match_bool(substring_t *s, int *result) |
| 578 | { |
| 579 | int len = s->to - s->from; |
| 580 | |
| 581 | if (strncmp(s->from, "on", len) == 0) |
| 582 | *result = 1; |
| 583 | else if (strncmp(s->from, "off", len) == 0) |
| 584 | *result = 0; |
| 585 | else |
| 586 | return 1; |
| 587 | return 0; |
| 588 | } |
| 589 | |
| 590 | static int parse_options(char *options, struct super_block *sb) |
| 591 | { |
| 592 | struct nilfs_sb_info *sbi = NILFS_SB(sb); |
| 593 | char *p; |
| 594 | substring_t args[MAX_OPT_ARGS]; |
| 595 | int option; |
| 596 | |
| 597 | if (!options) |
| 598 | return 1; |
| 599 | |
| 600 | while ((p = strsep(&options, ",")) != NULL) { |
| 601 | int token; |
| 602 | if (!*p) |
| 603 | continue; |
| 604 | |
| 605 | token = match_token(p, tokens, args); |
| 606 | switch (token) { |
| 607 | case Opt_barrier: |
| 608 | if (match_bool(&args[0], &option)) |
| 609 | return 0; |
| 610 | if (option) |
| 611 | nilfs_set_opt(sbi, BARRIER); |
| 612 | else |
| 613 | nilfs_clear_opt(sbi, BARRIER); |
| 614 | break; |
| 615 | case Opt_order: |
| 616 | if (strcmp(args[0].from, "relaxed") == 0) |
| 617 | /* Ordered data semantics */ |
| 618 | nilfs_clear_opt(sbi, STRICT_ORDER); |
| 619 | else if (strcmp(args[0].from, "strict") == 0) |
| 620 | /* Strict in-order semantics */ |
| 621 | nilfs_set_opt(sbi, STRICT_ORDER); |
| 622 | else |
| 623 | return 0; |
| 624 | break; |
| 625 | case Opt_err_panic: |
| 626 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC); |
| 627 | break; |
| 628 | case Opt_err_ro: |
| 629 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO); |
| 630 | break; |
| 631 | case Opt_err_cont: |
| 632 | nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT); |
| 633 | break; |
| 634 | case Opt_snapshot: |
| 635 | if (match_int(&args[0], &option) || option <= 0) |
| 636 | return 0; |
| 637 | if (!(sb->s_flags & MS_RDONLY)) |
| 638 | return 0; |
| 639 | sbi->s_snapshot_cno = option; |
| 640 | nilfs_set_opt(sbi, SNAPSHOT); |
| 641 | break; |
| 642 | default: |
| 643 | printk(KERN_ERR |
| 644 | "NILFS: Unrecognized mount option \"%s\"\n", p); |
| 645 | return 0; |
| 646 | } |
| 647 | } |
| 648 | return 1; |
| 649 | } |
| 650 | |
| 651 | static inline void |
| 652 | nilfs_set_default_options(struct nilfs_sb_info *sbi, |
| 653 | struct nilfs_super_block *sbp) |
| 654 | { |
| 655 | sbi->s_mount_opt = |
| 656 | NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER; |
| 657 | } |
| 658 | |
| 659 | static int nilfs_setup_super(struct nilfs_sb_info *sbi) |
| 660 | { |
| 661 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 662 | struct nilfs_super_block *sbp = nilfs->ns_sbp; |
| 663 | int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count); |
| 664 | int mnt_count = le16_to_cpu(sbp->s_mnt_count); |
| 665 | |
| 666 | /* nilfs->sem must be locked by the caller. */ |
| 667 | if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) { |
| 668 | printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); |
| 669 | } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) { |
| 670 | printk(KERN_WARNING |
| 671 | "NILFS warning: mounting fs with errors\n"); |
| 672 | #if 0 |
| 673 | } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { |
| 674 | printk(KERN_WARNING |
| 675 | "NILFS warning: maximal mount count reached\n"); |
| 676 | #endif |
| 677 | } |
| 678 | if (!max_mnt_count) |
| 679 | sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); |
| 680 | |
| 681 | sbp->s_mnt_count = cpu_to_le16(mnt_count + 1); |
| 682 | sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS); |
| 683 | sbp->s_mtime = cpu_to_le64(get_seconds()); |
| 684 | return nilfs_commit_super(sbi); |
| 685 | } |
| 686 | |
| 687 | struct nilfs_super_block * |
| 688 | nilfs_load_super_block(struct super_block *sb, struct buffer_head **pbh) |
| 689 | { |
| 690 | int blocksize; |
| 691 | unsigned long offset, sb_index; |
| 692 | |
| 693 | /* |
| 694 | * Adjusting block size |
| 695 | * Blocksize will be enlarged when it is smaller than hardware |
| 696 | * sector size. |
| 697 | * Disk format of superblock does not change. |
| 698 | */ |
| 699 | blocksize = sb_min_blocksize(sb, BLOCK_SIZE); |
| 700 | if (!blocksize) { |
| 701 | printk(KERN_ERR |
| 702 | "NILFS: unable to set blocksize of superblock\n"); |
| 703 | return NULL; |
| 704 | } |
| 705 | sb_index = NILFS_SB_OFFSET_BYTES / blocksize; |
| 706 | offset = NILFS_SB_OFFSET_BYTES % blocksize; |
| 707 | |
| 708 | *pbh = sb_bread(sb, sb_index); |
| 709 | if (!*pbh) { |
| 710 | printk(KERN_ERR "NILFS: unable to read superblock\n"); |
| 711 | return NULL; |
| 712 | } |
| 713 | return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); |
| 714 | } |
| 715 | |
| 716 | struct nilfs_super_block * |
| 717 | nilfs_reload_super_block(struct super_block *sb, struct buffer_head **pbh, |
| 718 | int blocksize) |
| 719 | { |
| 720 | struct nilfs_super_block *sbp; |
| 721 | unsigned long offset, sb_index; |
| 722 | int hw_blocksize = bdev_hardsect_size(sb->s_bdev); |
| 723 | |
| 724 | if (blocksize < hw_blocksize) { |
| 725 | printk(KERN_ERR |
| 726 | "NILFS: blocksize %d too small for device " |
| 727 | "(sector-size = %d).\n", |
| 728 | blocksize, hw_blocksize); |
| 729 | goto failed_sbh; |
| 730 | } |
| 731 | brelse(*pbh); |
| 732 | sb_set_blocksize(sb, blocksize); |
| 733 | |
| 734 | sb_index = NILFS_SB_OFFSET_BYTES / blocksize; |
| 735 | offset = NILFS_SB_OFFSET_BYTES % blocksize; |
| 736 | |
| 737 | *pbh = sb_bread(sb, sb_index); |
| 738 | if (!*pbh) { |
| 739 | printk(KERN_ERR |
| 740 | "NILFS: cannot read superblock on 2nd try.\n"); |
| 741 | goto failed; |
| 742 | } |
| 743 | |
| 744 | sbp = (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); |
| 745 | if (sbp->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { |
| 746 | printk(KERN_ERR |
| 747 | "NILFS: !? Magic mismatch on 2nd try.\n"); |
| 748 | goto failed_sbh; |
| 749 | } |
| 750 | return sbp; |
| 751 | |
| 752 | failed_sbh: |
| 753 | brelse(*pbh); |
| 754 | |
| 755 | failed: |
| 756 | return NULL; |
| 757 | } |
| 758 | |
| 759 | int nilfs_store_magic_and_option(struct super_block *sb, |
| 760 | struct nilfs_super_block *sbp, |
| 761 | char *data) |
| 762 | { |
| 763 | struct nilfs_sb_info *sbi = NILFS_SB(sb); |
| 764 | |
| 765 | /* trying to fill super (1st stage) */ |
| 766 | sb->s_magic = le16_to_cpu(sbp->s_magic); |
| 767 | |
| 768 | /* FS independent flags */ |
| 769 | #ifdef NILFS_ATIME_DISABLE |
| 770 | sb->s_flags |= MS_NOATIME; |
| 771 | #endif |
| 772 | |
| 773 | if (sb->s_magic != NILFS_SUPER_MAGIC) { |
| 774 | printk("NILFS: Can't find nilfs on dev %s.\n", sb->s_id); |
| 775 | return -EINVAL; |
| 776 | } |
| 777 | |
| 778 | nilfs_set_default_options(sbi, sbp); |
| 779 | |
| 780 | sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid); |
| 781 | sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid); |
| 782 | sbi->s_interval = le32_to_cpu(sbp->s_c_interval); |
| 783 | sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max); |
| 784 | |
| 785 | if (!parse_options(data, sb)) |
| 786 | return -EINVAL; |
| 787 | |
| 788 | return 0; |
| 789 | } |
| 790 | |
| 791 | /** |
| 792 | * nilfs_fill_super() - initialize a super block instance |
| 793 | * @sb: super_block |
| 794 | * @data: mount options |
| 795 | * @silent: silent mode flag |
| 796 | * @nilfs: the_nilfs struct |
| 797 | * |
| 798 | * This function is called exclusively by bd_mount_mutex. |
| 799 | * So, the recovery process is protected from other simultaneous mounts. |
| 800 | */ |
| 801 | static int |
| 802 | nilfs_fill_super(struct super_block *sb, void *data, int silent, |
| 803 | struct the_nilfs *nilfs) |
| 804 | { |
| 805 | struct nilfs_sb_info *sbi; |
| 806 | struct inode *root; |
| 807 | __u64 cno; |
| 808 | int err; |
| 809 | |
| 810 | sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); |
| 811 | if (!sbi) |
| 812 | return -ENOMEM; |
| 813 | |
| 814 | sb->s_fs_info = sbi; |
| 815 | |
| 816 | get_nilfs(nilfs); |
| 817 | sbi->s_nilfs = nilfs; |
| 818 | sbi->s_super = sb; |
| 819 | |
| 820 | err = init_nilfs(nilfs, sbi, (char *)data); |
| 821 | if (err) |
| 822 | goto failed_sbi; |
| 823 | |
| 824 | spin_lock_init(&sbi->s_inode_lock); |
| 825 | INIT_LIST_HEAD(&sbi->s_dirty_files); |
| 826 | INIT_LIST_HEAD(&sbi->s_list); |
| 827 | |
| 828 | /* |
| 829 | * Following initialization is overlapped because |
| 830 | * nilfs_sb_info structure has been cleared at the beginning. |
| 831 | * But we reserve them to keep our interest and make ready |
| 832 | * for the future change. |
| 833 | */ |
| 834 | get_random_bytes(&sbi->s_next_generation, |
| 835 | sizeof(sbi->s_next_generation)); |
| 836 | spin_lock_init(&sbi->s_next_gen_lock); |
| 837 | |
| 838 | sb->s_op = &nilfs_sops; |
| 839 | sb->s_export_op = &nilfs_export_ops; |
| 840 | sb->s_root = NULL; |
| 841 | |
| 842 | if (!nilfs_loaded(nilfs)) { |
| 843 | err = load_nilfs(nilfs, sbi); |
| 844 | if (err) |
| 845 | goto failed_sbi; |
| 846 | } |
| 847 | cno = nilfs_last_cno(nilfs); |
| 848 | |
| 849 | if (sb->s_flags & MS_RDONLY) { |
| 850 | if (nilfs_test_opt(sbi, SNAPSHOT)) { |
| 851 | if (!nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, |
| 852 | sbi->s_snapshot_cno)) { |
| 853 | printk(KERN_ERR |
| 854 | "NILFS: The specified checkpoint is " |
| 855 | "not a snapshot " |
| 856 | "(checkpoint number=%llu).\n", |
| 857 | (unsigned long long)sbi->s_snapshot_cno); |
| 858 | err = -EINVAL; |
| 859 | goto failed_sbi; |
| 860 | } |
| 861 | cno = sbi->s_snapshot_cno; |
| 862 | } else |
| 863 | /* Read-only mount */ |
| 864 | sbi->s_snapshot_cno = cno; |
| 865 | } |
| 866 | |
| 867 | err = nilfs_attach_checkpoint(sbi, cno); |
| 868 | if (err) { |
| 869 | printk(KERN_ERR "NILFS: error loading a checkpoint" |
| 870 | " (checkpoint number=%llu).\n", (unsigned long long)cno); |
| 871 | goto failed_sbi; |
| 872 | } |
| 873 | |
| 874 | if (!(sb->s_flags & MS_RDONLY)) { |
| 875 | err = nilfs_attach_segment_constructor(sbi, NULL); |
| 876 | if (err) |
| 877 | goto failed_checkpoint; |
| 878 | } |
| 879 | |
| 880 | root = nilfs_iget(sb, NILFS_ROOT_INO); |
| 881 | if (IS_ERR(root)) { |
| 882 | printk(KERN_ERR "NILFS: get root inode failed\n"); |
| 883 | err = PTR_ERR(root); |
| 884 | goto failed_segctor; |
| 885 | } |
| 886 | if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { |
| 887 | iput(root); |
| 888 | printk(KERN_ERR "NILFS: corrupt root inode.\n"); |
| 889 | err = -EINVAL; |
| 890 | goto failed_segctor; |
| 891 | } |
| 892 | sb->s_root = d_alloc_root(root); |
| 893 | if (!sb->s_root) { |
| 894 | iput(root); |
| 895 | printk(KERN_ERR "NILFS: get root dentry failed\n"); |
| 896 | err = -ENOMEM; |
| 897 | goto failed_segctor; |
| 898 | } |
| 899 | |
| 900 | if (!(sb->s_flags & MS_RDONLY)) { |
| 901 | down_write(&nilfs->ns_sem); |
| 902 | nilfs_setup_super(sbi); |
| 903 | up_write(&nilfs->ns_sem); |
| 904 | } |
| 905 | |
| 906 | err = nilfs_mark_recovery_complete(sbi); |
| 907 | if (unlikely(err)) { |
| 908 | printk(KERN_ERR "NILFS: recovery failed.\n"); |
| 909 | goto failed_root; |
| 910 | } |
| 911 | |
| 912 | return 0; |
| 913 | |
| 914 | failed_root: |
| 915 | dput(sb->s_root); |
| 916 | sb->s_root = NULL; |
| 917 | |
| 918 | failed_segctor: |
| 919 | nilfs_detach_segment_constructor(sbi); |
| 920 | |
| 921 | failed_checkpoint: |
| 922 | nilfs_detach_checkpoint(sbi); |
| 923 | |
| 924 | failed_sbi: |
| 925 | put_nilfs(nilfs); |
| 926 | sb->s_fs_info = NULL; |
| 927 | kfree(sbi); |
| 928 | return err; |
| 929 | } |
| 930 | |
| 931 | static int nilfs_remount(struct super_block *sb, int *flags, char *data) |
| 932 | { |
| 933 | struct nilfs_sb_info *sbi = NILFS_SB(sb); |
| 934 | struct nilfs_super_block *sbp; |
| 935 | struct the_nilfs *nilfs = sbi->s_nilfs; |
| 936 | unsigned long old_sb_flags; |
| 937 | struct nilfs_mount_options old_opts; |
| 938 | int err; |
| 939 | |
| 940 | old_sb_flags = sb->s_flags; |
| 941 | old_opts.mount_opt = sbi->s_mount_opt; |
| 942 | old_opts.snapshot_cno = sbi->s_snapshot_cno; |
| 943 | |
| 944 | if (!parse_options(data, sb)) { |
| 945 | err = -EINVAL; |
| 946 | goto restore_opts; |
| 947 | } |
| 948 | sb->s_flags = (sb->s_flags & ~MS_POSIXACL); |
| 949 | |
| 950 | if ((*flags & MS_RDONLY) && |
| 951 | sbi->s_snapshot_cno != old_opts.snapshot_cno) { |
| 952 | printk(KERN_WARNING "NILFS (device %s): couldn't " |
| 953 | "remount to a different snapshot. \n", |
| 954 | sb->s_id); |
| 955 | err = -EINVAL; |
| 956 | goto restore_opts; |
| 957 | } |
| 958 | |
| 959 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) |
| 960 | goto out; |
| 961 | if (*flags & MS_RDONLY) { |
| 962 | /* Shutting down the segment constructor */ |
| 963 | nilfs_detach_segment_constructor(sbi); |
| 964 | sb->s_flags |= MS_RDONLY; |
| 965 | |
| 966 | sbi->s_snapshot_cno = nilfs_last_cno(nilfs); |
| 967 | /* nilfs_set_opt(sbi, SNAPSHOT); */ |
| 968 | |
| 969 | /* |
| 970 | * Remounting a valid RW partition RDONLY, so set |
| 971 | * the RDONLY flag and then mark the partition as valid again. |
| 972 | */ |
| 973 | down_write(&nilfs->ns_sem); |
| 974 | sbp = nilfs->ns_sbp; |
| 975 | if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) && |
| 976 | (nilfs->ns_mount_state & NILFS_VALID_FS)) |
| 977 | sbp->s_state = cpu_to_le16(nilfs->ns_mount_state); |
| 978 | sbp->s_mtime = cpu_to_le64(get_seconds()); |
| 979 | nilfs_commit_super(sbi); |
| 980 | up_write(&nilfs->ns_sem); |
| 981 | } else { |
| 982 | /* |
| 983 | * Mounting a RDONLY partition read-write, so reread and |
| 984 | * store the current valid flag. (It may have been changed |
| 985 | * by fsck since we originally mounted the partition.) |
| 986 | */ |
| 987 | down(&sb->s_bdev->bd_mount_sem); |
| 988 | /* Check existing RW-mount */ |
| 989 | if (test_exclusive_mount(sb->s_type, sb->s_bdev, 0)) { |
| 990 | printk(KERN_WARNING "NILFS (device %s): couldn't " |
| 991 | "remount because a RW-mount exists.\n", |
| 992 | sb->s_id); |
| 993 | err = -EBUSY; |
| 994 | goto rw_remount_failed; |
| 995 | } |
| 996 | if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) { |
| 997 | printk(KERN_WARNING "NILFS (device %s): couldn't " |
| 998 | "remount because the current RO-mount is not " |
| 999 | "the latest one.\n", |
| 1000 | sb->s_id); |
| 1001 | err = -EINVAL; |
| 1002 | goto rw_remount_failed; |
| 1003 | } |
| 1004 | sb->s_flags &= ~MS_RDONLY; |
| 1005 | nilfs_clear_opt(sbi, SNAPSHOT); |
| 1006 | sbi->s_snapshot_cno = 0; |
| 1007 | |
| 1008 | err = nilfs_attach_segment_constructor(sbi, NULL); |
| 1009 | if (err) |
| 1010 | goto rw_remount_failed; |
| 1011 | |
| 1012 | down_write(&nilfs->ns_sem); |
| 1013 | nilfs_setup_super(sbi); |
| 1014 | up_write(&nilfs->ns_sem); |
| 1015 | |
| 1016 | up(&sb->s_bdev->bd_mount_sem); |
| 1017 | } |
| 1018 | out: |
| 1019 | return 0; |
| 1020 | |
| 1021 | rw_remount_failed: |
| 1022 | up(&sb->s_bdev->bd_mount_sem); |
| 1023 | restore_opts: |
| 1024 | sb->s_flags = old_sb_flags; |
| 1025 | sbi->s_mount_opt = old_opts.mount_opt; |
| 1026 | sbi->s_snapshot_cno = old_opts.snapshot_cno; |
| 1027 | return err; |
| 1028 | } |
| 1029 | |
| 1030 | struct nilfs_super_data { |
| 1031 | struct block_device *bdev; |
| 1032 | __u64 cno; |
| 1033 | int flags; |
| 1034 | }; |
| 1035 | |
| 1036 | /** |
| 1037 | * nilfs_identify - pre-read mount options needed to identify mount instance |
| 1038 | * @data: mount options |
| 1039 | * @sd: nilfs_super_data |
| 1040 | */ |
| 1041 | static int nilfs_identify(char *data, struct nilfs_super_data *sd) |
| 1042 | { |
| 1043 | char *p, *options = data; |
| 1044 | substring_t args[MAX_OPT_ARGS]; |
| 1045 | int option, token; |
| 1046 | int ret = 0; |
| 1047 | |
| 1048 | do { |
| 1049 | p = strsep(&options, ","); |
| 1050 | if (p != NULL && *p) { |
| 1051 | token = match_token(p, tokens, args); |
| 1052 | if (token == Opt_snapshot) { |
| 1053 | if (!(sd->flags & MS_RDONLY)) |
| 1054 | ret++; |
| 1055 | else { |
| 1056 | ret = match_int(&args[0], &option); |
| 1057 | if (!ret) { |
| 1058 | if (option > 0) |
| 1059 | sd->cno = option; |
| 1060 | else |
| 1061 | ret++; |
| 1062 | } |
| 1063 | } |
| 1064 | } |
| 1065 | if (ret) |
| 1066 | printk(KERN_ERR |
| 1067 | "NILFS: invalid mount option: %s\n", p); |
| 1068 | } |
| 1069 | if (!options) |
| 1070 | break; |
| 1071 | BUG_ON(options == data); |
| 1072 | *(options - 1) = ','; |
| 1073 | } while (!ret); |
| 1074 | return ret; |
| 1075 | } |
| 1076 | |
| 1077 | static int nilfs_set_bdev_super(struct super_block *s, void *data) |
| 1078 | { |
| 1079 | struct nilfs_super_data *sd = data; |
| 1080 | |
| 1081 | s->s_bdev = sd->bdev; |
| 1082 | s->s_dev = s->s_bdev->bd_dev; |
| 1083 | return 0; |
| 1084 | } |
| 1085 | |
| 1086 | static int nilfs_test_bdev_super(struct super_block *s, void *data) |
| 1087 | { |
| 1088 | struct nilfs_super_data *sd = data; |
| 1089 | |
| 1090 | return s->s_bdev == sd->bdev; |
| 1091 | } |
| 1092 | |
| 1093 | static int nilfs_test_bdev_super2(struct super_block *s, void *data) |
| 1094 | { |
| 1095 | struct nilfs_super_data *sd = data; |
| 1096 | int ret; |
| 1097 | |
| 1098 | if (s->s_bdev != sd->bdev) |
| 1099 | return 0; |
| 1100 | |
| 1101 | if (!((s->s_flags | sd->flags) & MS_RDONLY)) |
| 1102 | return 1; /* Reuse an old R/W-mode super_block */ |
| 1103 | |
| 1104 | if (s->s_flags & sd->flags & MS_RDONLY) { |
| 1105 | if (down_read_trylock(&s->s_umount)) { |
| 1106 | ret = s->s_root && |
| 1107 | (sd->cno == NILFS_SB(s)->s_snapshot_cno); |
| 1108 | up_read(&s->s_umount); |
| 1109 | /* |
| 1110 | * This path is locked with sb_lock by sget(). |
| 1111 | * So, drop_super() causes deadlock. |
| 1112 | */ |
| 1113 | return ret; |
| 1114 | } |
| 1115 | } |
| 1116 | return 0; |
| 1117 | } |
| 1118 | |
| 1119 | static int |
| 1120 | nilfs_get_sb(struct file_system_type *fs_type, int flags, |
| 1121 | const char *dev_name, void *data, struct vfsmount *mnt) |
| 1122 | { |
| 1123 | struct nilfs_super_data sd; |
| 1124 | struct super_block *s, *s2; |
| 1125 | struct the_nilfs *nilfs = NULL; |
| 1126 | int err, need_to_close = 1; |
| 1127 | |
| 1128 | sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type); |
| 1129 | if (IS_ERR(sd.bdev)) |
| 1130 | return PTR_ERR(sd.bdev); |
| 1131 | |
| 1132 | /* |
| 1133 | * To get mount instance using sget() vfs-routine, NILFS needs |
| 1134 | * much more information than normal filesystems to identify mount |
| 1135 | * instance. For snapshot mounts, not only a mount type (ro-mount |
| 1136 | * or rw-mount) but also a checkpoint number is required. |
| 1137 | * The results are passed in sget() using nilfs_super_data. |
| 1138 | */ |
| 1139 | sd.cno = 0; |
| 1140 | sd.flags = flags; |
| 1141 | if (nilfs_identify((char *)data, &sd)) { |
| 1142 | err = -EINVAL; |
| 1143 | goto failed; |
| 1144 | } |
| 1145 | |
| 1146 | /* |
| 1147 | * once the super is inserted into the list by sget, s_umount |
| 1148 | * will protect the lockfs code from trying to start a snapshot |
| 1149 | * while we are mounting |
| 1150 | */ |
| 1151 | down(&sd.bdev->bd_mount_sem); |
| 1152 | if (!sd.cno && |
| 1153 | (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) { |
| 1154 | err = (err < 0) ? : -EBUSY; |
| 1155 | goto failed_unlock; |
| 1156 | } |
| 1157 | |
| 1158 | /* |
| 1159 | * Phase-1: search any existent instance and get the_nilfs |
| 1160 | */ |
| 1161 | s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd); |
| 1162 | if (IS_ERR(s)) |
| 1163 | goto error_s; |
| 1164 | |
| 1165 | if (!s->s_root) { |
| 1166 | err = -ENOMEM; |
| 1167 | nilfs = alloc_nilfs(sd.bdev); |
| 1168 | if (!nilfs) |
| 1169 | goto cancel_new; |
| 1170 | } else { |
| 1171 | struct nilfs_sb_info *sbi = NILFS_SB(s); |
| 1172 | |
| 1173 | BUG_ON(!sbi || !sbi->s_nilfs); |
| 1174 | /* |
| 1175 | * s_umount protects super_block from unmount process; |
| 1176 | * It covers pointers of nilfs_sb_info and the_nilfs. |
| 1177 | */ |
| 1178 | nilfs = sbi->s_nilfs; |
| 1179 | get_nilfs(nilfs); |
| 1180 | up_write(&s->s_umount); |
| 1181 | |
| 1182 | /* |
| 1183 | * Phase-2: search specified snapshot or R/W mode super_block |
| 1184 | */ |
| 1185 | if (!sd.cno) |
| 1186 | /* trying to get the latest checkpoint. */ |
| 1187 | sd.cno = nilfs_last_cno(nilfs); |
| 1188 | |
| 1189 | s2 = sget(fs_type, nilfs_test_bdev_super2, |
| 1190 | nilfs_set_bdev_super, &sd); |
| 1191 | deactivate_super(s); |
| 1192 | /* |
| 1193 | * Although deactivate_super() invokes close_bdev_exclusive() at |
| 1194 | * kill_block_super(). Here, s is an existent mount; we need |
| 1195 | * one more close_bdev_exclusive() call. |
| 1196 | */ |
| 1197 | s = s2; |
| 1198 | if (IS_ERR(s)) |
| 1199 | goto error_s; |
| 1200 | } |
| 1201 | |
| 1202 | if (!s->s_root) { |
| 1203 | char b[BDEVNAME_SIZE]; |
| 1204 | |
| 1205 | s->s_flags = flags; |
| 1206 | strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); |
| 1207 | sb_set_blocksize(s, block_size(sd.bdev)); |
| 1208 | |
| 1209 | err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs); |
| 1210 | if (err) |
| 1211 | goto cancel_new; |
| 1212 | |
| 1213 | s->s_flags |= MS_ACTIVE; |
| 1214 | need_to_close = 0; |
| 1215 | } else if (!(s->s_flags & MS_RDONLY)) { |
| 1216 | err = -EBUSY; |
| 1217 | } |
| 1218 | |
| 1219 | up(&sd.bdev->bd_mount_sem); |
| 1220 | put_nilfs(nilfs); |
| 1221 | if (need_to_close) |
| 1222 | close_bdev_exclusive(sd.bdev, flags); |
| 1223 | simple_set_mnt(mnt, s); |
| 1224 | return 0; |
| 1225 | |
| 1226 | error_s: |
| 1227 | up(&sd.bdev->bd_mount_sem); |
| 1228 | if (nilfs) |
| 1229 | put_nilfs(nilfs); |
| 1230 | close_bdev_exclusive(sd.bdev, flags); |
| 1231 | return PTR_ERR(s); |
| 1232 | |
| 1233 | failed_unlock: |
| 1234 | up(&sd.bdev->bd_mount_sem); |
| 1235 | failed: |
| 1236 | close_bdev_exclusive(sd.bdev, flags); |
| 1237 | |
| 1238 | return err; |
| 1239 | |
| 1240 | cancel_new: |
| 1241 | /* Abandoning the newly allocated superblock */ |
| 1242 | up(&sd.bdev->bd_mount_sem); |
| 1243 | if (nilfs) |
| 1244 | put_nilfs(nilfs); |
| 1245 | up_write(&s->s_umount); |
| 1246 | deactivate_super(s); |
| 1247 | /* |
| 1248 | * deactivate_super() invokes close_bdev_exclusive(). |
| 1249 | * We must finish all post-cleaning before this call; |
| 1250 | * put_nilfs() and unlocking bd_mount_sem need the block device. |
| 1251 | */ |
| 1252 | return err; |
| 1253 | } |
| 1254 | |
| 1255 | static int nilfs_test_bdev_super3(struct super_block *s, void *data) |
| 1256 | { |
| 1257 | struct nilfs_super_data *sd = data; |
| 1258 | int ret; |
| 1259 | |
| 1260 | if (s->s_bdev != sd->bdev) |
| 1261 | return 0; |
| 1262 | if (down_read_trylock(&s->s_umount)) { |
| 1263 | ret = (s->s_flags & MS_RDONLY) && s->s_root && |
| 1264 | nilfs_test_opt(NILFS_SB(s), SNAPSHOT); |
| 1265 | up_read(&s->s_umount); |
| 1266 | if (ret) |
| 1267 | return 0; /* ignore snapshot mounts */ |
| 1268 | } |
| 1269 | return !((sd->flags ^ s->s_flags) & MS_RDONLY); |
| 1270 | } |
| 1271 | |
| 1272 | static int __false_bdev_super(struct super_block *s, void *data) |
| 1273 | { |
| 1274 | #if 0 /* XXX: workaround for lock debug. This is not good idea */ |
| 1275 | up_write(&s->s_umount); |
| 1276 | #endif |
| 1277 | return -EFAULT; |
| 1278 | } |
| 1279 | |
| 1280 | /** |
| 1281 | * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not. |
| 1282 | * fs_type: filesystem type |
| 1283 | * bdev: block device |
| 1284 | * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount) |
| 1285 | * res: pointer to an integer to store result |
| 1286 | * |
| 1287 | * This function must be called within a section protected by bd_mount_mutex. |
| 1288 | */ |
| 1289 | static int test_exclusive_mount(struct file_system_type *fs_type, |
| 1290 | struct block_device *bdev, int flags) |
| 1291 | { |
| 1292 | struct super_block *s; |
| 1293 | struct nilfs_super_data sd = { .flags = flags, .bdev = bdev }; |
| 1294 | |
| 1295 | s = sget(fs_type, nilfs_test_bdev_super3, __false_bdev_super, &sd); |
| 1296 | if (IS_ERR(s)) { |
| 1297 | if (PTR_ERR(s) != -EFAULT) |
| 1298 | return PTR_ERR(s); |
| 1299 | return 0; /* Not found */ |
| 1300 | } |
| 1301 | up_write(&s->s_umount); |
| 1302 | deactivate_super(s); |
| 1303 | return 1; /* Found */ |
| 1304 | } |
| 1305 | |
| 1306 | struct file_system_type nilfs_fs_type = { |
| 1307 | .owner = THIS_MODULE, |
| 1308 | .name = "nilfs2", |
| 1309 | .get_sb = nilfs_get_sb, |
| 1310 | .kill_sb = kill_block_super, |
| 1311 | .fs_flags = FS_REQUIRES_DEV, |
| 1312 | }; |
| 1313 | |
| 1314 | static int __init init_nilfs_fs(void) |
| 1315 | { |
| 1316 | int err; |
| 1317 | |
| 1318 | err = nilfs_init_inode_cache(); |
| 1319 | if (err) |
| 1320 | goto failed; |
| 1321 | |
| 1322 | err = nilfs_init_transaction_cache(); |
| 1323 | if (err) |
| 1324 | goto failed_inode_cache; |
| 1325 | |
| 1326 | err = nilfs_init_segbuf_cache(); |
| 1327 | if (err) |
| 1328 | goto failed_transaction_cache; |
| 1329 | |
| 1330 | err = nilfs_btree_path_cache_init(); |
| 1331 | if (err) |
| 1332 | goto failed_segbuf_cache; |
| 1333 | |
| 1334 | err = register_filesystem(&nilfs_fs_type); |
| 1335 | if (err) |
| 1336 | goto failed_btree_path_cache; |
| 1337 | |
| 1338 | return 0; |
| 1339 | |
| 1340 | failed_btree_path_cache: |
| 1341 | nilfs_btree_path_cache_destroy(); |
| 1342 | |
| 1343 | failed_segbuf_cache: |
| 1344 | nilfs_destroy_segbuf_cache(); |
| 1345 | |
| 1346 | failed_transaction_cache: |
| 1347 | nilfs_destroy_transaction_cache(); |
| 1348 | |
| 1349 | failed_inode_cache: |
| 1350 | nilfs_destroy_inode_cache(); |
| 1351 | |
| 1352 | failed: |
| 1353 | return err; |
| 1354 | } |
| 1355 | |
| 1356 | static void __exit exit_nilfs_fs(void) |
| 1357 | { |
| 1358 | nilfs_destroy_segbuf_cache(); |
| 1359 | nilfs_destroy_transaction_cache(); |
| 1360 | nilfs_destroy_inode_cache(); |
| 1361 | nilfs_btree_path_cache_destroy(); |
| 1362 | unregister_filesystem(&nilfs_fs_type); |
| 1363 | } |
| 1364 | |
| 1365 | module_init(init_nilfs_fs) |
| 1366 | module_exit(exit_nilfs_fs) |