| 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/crc32.h> |
| 47 | #include <linux/vfs.h> |
| 48 | #include <linux/writeback.h> |
| 49 | #include <linux/seq_file.h> |
| 50 | #include <linux/mount.h> |
| 51 | #include "nilfs.h" |
| 52 | #include "export.h" |
| 53 | #include "mdt.h" |
| 54 | #include "alloc.h" |
| 55 | #include "btree.h" |
| 56 | #include "btnode.h" |
| 57 | #include "page.h" |
| 58 | #include "cpfile.h" |
| 59 | #include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */ |
| 60 | #include "ifile.h" |
| 61 | #include "dat.h" |
| 62 | #include "segment.h" |
| 63 | #include "segbuf.h" |
| 64 | |
| 65 | MODULE_AUTHOR("NTT Corp."); |
| 66 | MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem " |
| 67 | "(NILFS)"); |
| 68 | MODULE_LICENSE("GPL"); |
| 69 | |
| 70 | static struct kmem_cache *nilfs_inode_cachep; |
| 71 | struct kmem_cache *nilfs_transaction_cachep; |
| 72 | struct kmem_cache *nilfs_segbuf_cachep; |
| 73 | struct kmem_cache *nilfs_btree_path_cache; |
| 74 | |
| 75 | static int nilfs_setup_super(struct super_block *sb, int is_mount); |
| 76 | static int nilfs_remount(struct super_block *sb, int *flags, char *data); |
| 77 | |
| 78 | static void nilfs_set_error(struct super_block *sb) |
| 79 | { |
| 80 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 81 | struct nilfs_super_block **sbp; |
| 82 | |
| 83 | down_write(&nilfs->ns_sem); |
| 84 | if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { |
| 85 | nilfs->ns_mount_state |= NILFS_ERROR_FS; |
| 86 | sbp = nilfs_prepare_super(sb, 0); |
| 87 | if (likely(sbp)) { |
| 88 | sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS); |
| 89 | if (sbp[1]) |
| 90 | sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS); |
| 91 | nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); |
| 92 | } |
| 93 | } |
| 94 | up_write(&nilfs->ns_sem); |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * nilfs_error() - report failure condition on a filesystem |
| 99 | * |
| 100 | * nilfs_error() sets an ERROR_FS flag on the superblock as well as |
| 101 | * reporting an error message. It should be called when NILFS detects |
| 102 | * incoherences or defects of meta data on disk. As for sustainable |
| 103 | * errors such as a single-shot I/O error, nilfs_warning() or the printk() |
| 104 | * function should be used instead. |
| 105 | * |
| 106 | * The segment constructor must not call this function because it can |
| 107 | * kill itself. |
| 108 | */ |
| 109 | void nilfs_error(struct super_block *sb, const char *function, |
| 110 | const char *fmt, ...) |
| 111 | { |
| 112 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 113 | struct va_format vaf; |
| 114 | va_list args; |
| 115 | |
| 116 | va_start(args, fmt); |
| 117 | |
| 118 | vaf.fmt = fmt; |
| 119 | vaf.va = &args; |
| 120 | |
| 121 | printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n", |
| 122 | sb->s_id, function, &vaf); |
| 123 | |
| 124 | va_end(args); |
| 125 | |
| 126 | if (!(sb->s_flags & MS_RDONLY)) { |
| 127 | nilfs_set_error(sb); |
| 128 | |
| 129 | if (nilfs_test_opt(nilfs, ERRORS_RO)) { |
| 130 | printk(KERN_CRIT "Remounting filesystem read-only\n"); |
| 131 | sb->s_flags |= MS_RDONLY; |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | if (nilfs_test_opt(nilfs, ERRORS_PANIC)) |
| 136 | panic("NILFS (device %s): panic forced after error\n", |
| 137 | sb->s_id); |
| 138 | } |
| 139 | |
| 140 | void nilfs_warning(struct super_block *sb, const char *function, |
| 141 | const char *fmt, ...) |
| 142 | { |
| 143 | struct va_format vaf; |
| 144 | va_list args; |
| 145 | |
| 146 | va_start(args, fmt); |
| 147 | |
| 148 | vaf.fmt = fmt; |
| 149 | vaf.va = &args; |
| 150 | |
| 151 | printk(KERN_WARNING "NILFS warning (device %s): %s: %pV\n", |
| 152 | sb->s_id, function, &vaf); |
| 153 | |
| 154 | va_end(args); |
| 155 | } |
| 156 | |
| 157 | |
| 158 | struct inode *nilfs_alloc_inode(struct super_block *sb) |
| 159 | { |
| 160 | struct nilfs_inode_info *ii; |
| 161 | |
| 162 | ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS); |
| 163 | if (!ii) |
| 164 | return NULL; |
| 165 | ii->i_bh = NULL; |
| 166 | ii->i_state = 0; |
| 167 | ii->i_cno = 0; |
| 168 | ii->vfs_inode.i_version = 1; |
| 169 | nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode, sb->s_bdi); |
| 170 | return &ii->vfs_inode; |
| 171 | } |
| 172 | |
| 173 | static void nilfs_i_callback(struct rcu_head *head) |
| 174 | { |
| 175 | struct inode *inode = container_of(head, struct inode, i_rcu); |
| 176 | struct nilfs_mdt_info *mdi = NILFS_MDT(inode); |
| 177 | |
| 178 | if (mdi) { |
| 179 | kfree(mdi->mi_bgl); /* kfree(NULL) is safe */ |
| 180 | kfree(mdi); |
| 181 | } |
| 182 | kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); |
| 183 | } |
| 184 | |
| 185 | void nilfs_destroy_inode(struct inode *inode) |
| 186 | { |
| 187 | call_rcu(&inode->i_rcu, nilfs_i_callback); |
| 188 | } |
| 189 | |
| 190 | static int nilfs_sync_super(struct super_block *sb, int flag) |
| 191 | { |
| 192 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 193 | int err; |
| 194 | |
| 195 | retry: |
| 196 | set_buffer_dirty(nilfs->ns_sbh[0]); |
| 197 | if (nilfs_test_opt(nilfs, BARRIER)) { |
| 198 | err = __sync_dirty_buffer(nilfs->ns_sbh[0], |
| 199 | WRITE_SYNC | WRITE_FLUSH_FUA); |
| 200 | } else { |
| 201 | err = sync_dirty_buffer(nilfs->ns_sbh[0]); |
| 202 | } |
| 203 | |
| 204 | if (unlikely(err)) { |
| 205 | printk(KERN_ERR |
| 206 | "NILFS: unable to write superblock (err=%d)\n", err); |
| 207 | if (err == -EIO && nilfs->ns_sbh[1]) { |
| 208 | /* |
| 209 | * sbp[0] points to newer log than sbp[1], |
| 210 | * so copy sbp[0] to sbp[1] to take over sbp[0]. |
| 211 | */ |
| 212 | memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0], |
| 213 | nilfs->ns_sbsize); |
| 214 | nilfs_fall_back_super_block(nilfs); |
| 215 | goto retry; |
| 216 | } |
| 217 | } else { |
| 218 | struct nilfs_super_block *sbp = nilfs->ns_sbp[0]; |
| 219 | |
| 220 | nilfs->ns_sbwcount++; |
| 221 | |
| 222 | /* |
| 223 | * The latest segment becomes trailable from the position |
| 224 | * written in superblock. |
| 225 | */ |
| 226 | clear_nilfs_discontinued(nilfs); |
| 227 | |
| 228 | /* update GC protection for recent segments */ |
| 229 | if (nilfs->ns_sbh[1]) { |
| 230 | if (flag == NILFS_SB_COMMIT_ALL) { |
| 231 | set_buffer_dirty(nilfs->ns_sbh[1]); |
| 232 | if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0) |
| 233 | goto out; |
| 234 | } |
| 235 | if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) < |
| 236 | le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno)) |
| 237 | sbp = nilfs->ns_sbp[1]; |
| 238 | } |
| 239 | |
| 240 | spin_lock(&nilfs->ns_last_segment_lock); |
| 241 | nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq); |
| 242 | spin_unlock(&nilfs->ns_last_segment_lock); |
| 243 | } |
| 244 | out: |
| 245 | return err; |
| 246 | } |
| 247 | |
| 248 | void nilfs_set_log_cursor(struct nilfs_super_block *sbp, |
| 249 | struct the_nilfs *nilfs) |
| 250 | { |
| 251 | sector_t nfreeblocks; |
| 252 | |
| 253 | /* nilfs->ns_sem must be locked by the caller. */ |
| 254 | nilfs_count_free_blocks(nilfs, &nfreeblocks); |
| 255 | sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks); |
| 256 | |
| 257 | spin_lock(&nilfs->ns_last_segment_lock); |
| 258 | sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); |
| 259 | sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); |
| 260 | sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); |
| 261 | spin_unlock(&nilfs->ns_last_segment_lock); |
| 262 | } |
| 263 | |
| 264 | struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb, |
| 265 | int flip) |
| 266 | { |
| 267 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 268 | struct nilfs_super_block **sbp = nilfs->ns_sbp; |
| 269 | |
| 270 | /* nilfs->ns_sem must be locked by the caller. */ |
| 271 | if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { |
| 272 | if (sbp[1] && |
| 273 | sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) { |
| 274 | memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); |
| 275 | } else { |
| 276 | printk(KERN_CRIT "NILFS: superblock broke on dev %s\n", |
| 277 | sb->s_id); |
| 278 | return NULL; |
| 279 | } |
| 280 | } else if (sbp[1] && |
| 281 | sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { |
| 282 | memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); |
| 283 | } |
| 284 | |
| 285 | if (flip && sbp[1]) |
| 286 | nilfs_swap_super_block(nilfs); |
| 287 | |
| 288 | return sbp; |
| 289 | } |
| 290 | |
| 291 | int nilfs_commit_super(struct super_block *sb, int flag) |
| 292 | { |
| 293 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 294 | struct nilfs_super_block **sbp = nilfs->ns_sbp; |
| 295 | time_t t; |
| 296 | |
| 297 | /* nilfs->ns_sem must be locked by the caller. */ |
| 298 | t = get_seconds(); |
| 299 | nilfs->ns_sbwtime = t; |
| 300 | sbp[0]->s_wtime = cpu_to_le64(t); |
| 301 | sbp[0]->s_sum = 0; |
| 302 | sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, |
| 303 | (unsigned char *)sbp[0], |
| 304 | nilfs->ns_sbsize)); |
| 305 | if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) { |
| 306 | sbp[1]->s_wtime = sbp[0]->s_wtime; |
| 307 | sbp[1]->s_sum = 0; |
| 308 | sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, |
| 309 | (unsigned char *)sbp[1], |
| 310 | nilfs->ns_sbsize)); |
| 311 | } |
| 312 | clear_nilfs_sb_dirty(nilfs); |
| 313 | return nilfs_sync_super(sb, flag); |
| 314 | } |
| 315 | |
| 316 | /** |
| 317 | * nilfs_cleanup_super() - write filesystem state for cleanup |
| 318 | * @sb: super block instance to be unmounted or degraded to read-only |
| 319 | * |
| 320 | * This function restores state flags in the on-disk super block. |
| 321 | * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the |
| 322 | * filesystem was not clean previously. |
| 323 | */ |
| 324 | int nilfs_cleanup_super(struct super_block *sb) |
| 325 | { |
| 326 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 327 | struct nilfs_super_block **sbp; |
| 328 | int flag = NILFS_SB_COMMIT; |
| 329 | int ret = -EIO; |
| 330 | |
| 331 | sbp = nilfs_prepare_super(sb, 0); |
| 332 | if (sbp) { |
| 333 | sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state); |
| 334 | nilfs_set_log_cursor(sbp[0], nilfs); |
| 335 | if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) { |
| 336 | /* |
| 337 | * make the "clean" flag also to the opposite |
| 338 | * super block if both super blocks point to |
| 339 | * the same checkpoint. |
| 340 | */ |
| 341 | sbp[1]->s_state = sbp[0]->s_state; |
| 342 | flag = NILFS_SB_COMMIT_ALL; |
| 343 | } |
| 344 | ret = nilfs_commit_super(sb, flag); |
| 345 | } |
| 346 | return ret; |
| 347 | } |
| 348 | |
| 349 | /** |
| 350 | * nilfs_move_2nd_super - relocate secondary super block |
| 351 | * @sb: super block instance |
| 352 | * @sb2off: new offset of the secondary super block (in bytes) |
| 353 | */ |
| 354 | static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off) |
| 355 | { |
| 356 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 357 | struct buffer_head *nsbh; |
| 358 | struct nilfs_super_block *nsbp; |
| 359 | sector_t blocknr, newblocknr; |
| 360 | unsigned long offset; |
| 361 | int sb2i = -1; /* array index of the secondary superblock */ |
| 362 | int ret = 0; |
| 363 | |
| 364 | /* nilfs->ns_sem must be locked by the caller. */ |
| 365 | if (nilfs->ns_sbh[1] && |
| 366 | nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) { |
| 367 | sb2i = 1; |
| 368 | blocknr = nilfs->ns_sbh[1]->b_blocknr; |
| 369 | } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) { |
| 370 | sb2i = 0; |
| 371 | blocknr = nilfs->ns_sbh[0]->b_blocknr; |
| 372 | } |
| 373 | if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off) |
| 374 | goto out; /* super block location is unchanged */ |
| 375 | |
| 376 | /* Get new super block buffer */ |
| 377 | newblocknr = sb2off >> nilfs->ns_blocksize_bits; |
| 378 | offset = sb2off & (nilfs->ns_blocksize - 1); |
| 379 | nsbh = sb_getblk(sb, newblocknr); |
| 380 | if (!nsbh) { |
| 381 | printk(KERN_WARNING |
| 382 | "NILFS warning: unable to move secondary superblock " |
| 383 | "to block %llu\n", (unsigned long long)newblocknr); |
| 384 | ret = -EIO; |
| 385 | goto out; |
| 386 | } |
| 387 | nsbp = (void *)nsbh->b_data + offset; |
| 388 | memset(nsbp, 0, nilfs->ns_blocksize); |
| 389 | |
| 390 | if (sb2i >= 0) { |
| 391 | memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize); |
| 392 | brelse(nilfs->ns_sbh[sb2i]); |
| 393 | nilfs->ns_sbh[sb2i] = nsbh; |
| 394 | nilfs->ns_sbp[sb2i] = nsbp; |
| 395 | } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) { |
| 396 | /* secondary super block will be restored to index 1 */ |
| 397 | nilfs->ns_sbh[1] = nsbh; |
| 398 | nilfs->ns_sbp[1] = nsbp; |
| 399 | } else { |
| 400 | brelse(nsbh); |
| 401 | } |
| 402 | out: |
| 403 | return ret; |
| 404 | } |
| 405 | |
| 406 | /** |
| 407 | * nilfs_resize_fs - resize the filesystem |
| 408 | * @sb: super block instance |
| 409 | * @newsize: new size of the filesystem (in bytes) |
| 410 | */ |
| 411 | int nilfs_resize_fs(struct super_block *sb, __u64 newsize) |
| 412 | { |
| 413 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 414 | struct nilfs_super_block **sbp; |
| 415 | __u64 devsize, newnsegs; |
| 416 | loff_t sb2off; |
| 417 | int ret; |
| 418 | |
| 419 | ret = -ERANGE; |
| 420 | devsize = i_size_read(sb->s_bdev->bd_inode); |
| 421 | if (newsize > devsize) |
| 422 | goto out; |
| 423 | |
| 424 | /* |
| 425 | * Write lock is required to protect some functions depending |
| 426 | * on the number of segments, the number of reserved segments, |
| 427 | * and so forth. |
| 428 | */ |
| 429 | down_write(&nilfs->ns_segctor_sem); |
| 430 | |
| 431 | sb2off = NILFS_SB2_OFFSET_BYTES(newsize); |
| 432 | newnsegs = sb2off >> nilfs->ns_blocksize_bits; |
| 433 | do_div(newnsegs, nilfs->ns_blocks_per_segment); |
| 434 | |
| 435 | ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs); |
| 436 | up_write(&nilfs->ns_segctor_sem); |
| 437 | if (ret < 0) |
| 438 | goto out; |
| 439 | |
| 440 | ret = nilfs_construct_segment(sb); |
| 441 | if (ret < 0) |
| 442 | goto out; |
| 443 | |
| 444 | down_write(&nilfs->ns_sem); |
| 445 | nilfs_move_2nd_super(sb, sb2off); |
| 446 | ret = -EIO; |
| 447 | sbp = nilfs_prepare_super(sb, 0); |
| 448 | if (likely(sbp)) { |
| 449 | nilfs_set_log_cursor(sbp[0], nilfs); |
| 450 | /* |
| 451 | * Drop NILFS_RESIZE_FS flag for compatibility with |
| 452 | * mount-time resize which may be implemented in a |
| 453 | * future release. |
| 454 | */ |
| 455 | sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & |
| 456 | ~NILFS_RESIZE_FS); |
| 457 | sbp[0]->s_dev_size = cpu_to_le64(newsize); |
| 458 | sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments); |
| 459 | if (sbp[1]) |
| 460 | memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); |
| 461 | ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); |
| 462 | } |
| 463 | up_write(&nilfs->ns_sem); |
| 464 | |
| 465 | /* |
| 466 | * Reset the range of allocatable segments last. This order |
| 467 | * is important in the case of expansion because the secondary |
| 468 | * superblock must be protected from log write until migration |
| 469 | * completes. |
| 470 | */ |
| 471 | if (!ret) |
| 472 | nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1); |
| 473 | out: |
| 474 | return ret; |
| 475 | } |
| 476 | |
| 477 | static void nilfs_put_super(struct super_block *sb) |
| 478 | { |
| 479 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 480 | |
| 481 | nilfs_detach_log_writer(sb); |
| 482 | |
| 483 | if (!(sb->s_flags & MS_RDONLY)) { |
| 484 | down_write(&nilfs->ns_sem); |
| 485 | nilfs_cleanup_super(sb); |
| 486 | up_write(&nilfs->ns_sem); |
| 487 | } |
| 488 | |
| 489 | iput(nilfs->ns_sufile); |
| 490 | iput(nilfs->ns_cpfile); |
| 491 | iput(nilfs->ns_dat); |
| 492 | |
| 493 | destroy_nilfs(nilfs); |
| 494 | sb->s_fs_info = NULL; |
| 495 | } |
| 496 | |
| 497 | static int nilfs_sync_fs(struct super_block *sb, int wait) |
| 498 | { |
| 499 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 500 | struct nilfs_super_block **sbp; |
| 501 | int err = 0; |
| 502 | |
| 503 | /* This function is called when super block should be written back */ |
| 504 | if (wait) |
| 505 | err = nilfs_construct_segment(sb); |
| 506 | |
| 507 | down_write(&nilfs->ns_sem); |
| 508 | if (nilfs_sb_dirty(nilfs)) { |
| 509 | sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs)); |
| 510 | if (likely(sbp)) { |
| 511 | nilfs_set_log_cursor(sbp[0], nilfs); |
| 512 | nilfs_commit_super(sb, NILFS_SB_COMMIT); |
| 513 | } |
| 514 | } |
| 515 | up_write(&nilfs->ns_sem); |
| 516 | |
| 517 | return err; |
| 518 | } |
| 519 | |
| 520 | int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt, |
| 521 | struct nilfs_root **rootp) |
| 522 | { |
| 523 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 524 | struct nilfs_root *root; |
| 525 | struct nilfs_checkpoint *raw_cp; |
| 526 | struct buffer_head *bh_cp; |
| 527 | int err = -ENOMEM; |
| 528 | |
| 529 | root = nilfs_find_or_create_root( |
| 530 | nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno); |
| 531 | if (!root) |
| 532 | return err; |
| 533 | |
| 534 | if (root->ifile) |
| 535 | goto reuse; /* already attached checkpoint */ |
| 536 | |
| 537 | down_read(&nilfs->ns_segctor_sem); |
| 538 | err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, |
| 539 | &bh_cp); |
| 540 | up_read(&nilfs->ns_segctor_sem); |
| 541 | if (unlikely(err)) { |
| 542 | if (err == -ENOENT || err == -EINVAL) { |
| 543 | printk(KERN_ERR |
| 544 | "NILFS: Invalid checkpoint " |
| 545 | "(checkpoint number=%llu)\n", |
| 546 | (unsigned long long)cno); |
| 547 | err = -EINVAL; |
| 548 | } |
| 549 | goto failed; |
| 550 | } |
| 551 | |
| 552 | err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size, |
| 553 | &raw_cp->cp_ifile_inode, &root->ifile); |
| 554 | if (err) |
| 555 | goto failed_bh; |
| 556 | |
| 557 | atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count)); |
| 558 | atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count)); |
| 559 | |
| 560 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); |
| 561 | |
| 562 | reuse: |
| 563 | *rootp = root; |
| 564 | return 0; |
| 565 | |
| 566 | failed_bh: |
| 567 | nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); |
| 568 | failed: |
| 569 | nilfs_put_root(root); |
| 570 | |
| 571 | return err; |
| 572 | } |
| 573 | |
| 574 | static int nilfs_freeze(struct super_block *sb) |
| 575 | { |
| 576 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 577 | int err; |
| 578 | |
| 579 | if (sb->s_flags & MS_RDONLY) |
| 580 | return 0; |
| 581 | |
| 582 | /* Mark super block clean */ |
| 583 | down_write(&nilfs->ns_sem); |
| 584 | err = nilfs_cleanup_super(sb); |
| 585 | up_write(&nilfs->ns_sem); |
| 586 | return err; |
| 587 | } |
| 588 | |
| 589 | static int nilfs_unfreeze(struct super_block *sb) |
| 590 | { |
| 591 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 592 | |
| 593 | if (sb->s_flags & MS_RDONLY) |
| 594 | return 0; |
| 595 | |
| 596 | down_write(&nilfs->ns_sem); |
| 597 | nilfs_setup_super(sb, false); |
| 598 | up_write(&nilfs->ns_sem); |
| 599 | return 0; |
| 600 | } |
| 601 | |
| 602 | static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 603 | { |
| 604 | struct super_block *sb = dentry->d_sb; |
| 605 | struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root; |
| 606 | struct the_nilfs *nilfs = root->nilfs; |
| 607 | u64 id = huge_encode_dev(sb->s_bdev->bd_dev); |
| 608 | unsigned long long blocks; |
| 609 | unsigned long overhead; |
| 610 | unsigned long nrsvblocks; |
| 611 | sector_t nfreeblocks; |
| 612 | int err; |
| 613 | |
| 614 | /* |
| 615 | * Compute all of the segment blocks |
| 616 | * |
| 617 | * The blocks before first segment and after last segment |
| 618 | * are excluded. |
| 619 | */ |
| 620 | blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments |
| 621 | - nilfs->ns_first_data_block; |
| 622 | nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; |
| 623 | |
| 624 | /* |
| 625 | * Compute the overhead |
| 626 | * |
| 627 | * When distributing meta data blocks outside segment structure, |
| 628 | * We must count them as the overhead. |
| 629 | */ |
| 630 | overhead = 0; |
| 631 | |
| 632 | err = nilfs_count_free_blocks(nilfs, &nfreeblocks); |
| 633 | if (unlikely(err)) |
| 634 | return err; |
| 635 | |
| 636 | buf->f_type = NILFS_SUPER_MAGIC; |
| 637 | buf->f_bsize = sb->s_blocksize; |
| 638 | buf->f_blocks = blocks - overhead; |
| 639 | buf->f_bfree = nfreeblocks; |
| 640 | buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? |
| 641 | (buf->f_bfree - nrsvblocks) : 0; |
| 642 | buf->f_files = atomic_read(&root->inodes_count); |
| 643 | buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */ |
| 644 | buf->f_namelen = NILFS_NAME_LEN; |
| 645 | buf->f_fsid.val[0] = (u32)id; |
| 646 | buf->f_fsid.val[1] = (u32)(id >> 32); |
| 647 | |
| 648 | return 0; |
| 649 | } |
| 650 | |
| 651 | static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry) |
| 652 | { |
| 653 | struct super_block *sb = dentry->d_sb; |
| 654 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 655 | struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root; |
| 656 | |
| 657 | if (!nilfs_test_opt(nilfs, BARRIER)) |
| 658 | seq_puts(seq, ",nobarrier"); |
| 659 | if (root->cno != NILFS_CPTREE_CURRENT_CNO) |
| 660 | seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno); |
| 661 | if (nilfs_test_opt(nilfs, ERRORS_PANIC)) |
| 662 | seq_puts(seq, ",errors=panic"); |
| 663 | if (nilfs_test_opt(nilfs, ERRORS_CONT)) |
| 664 | seq_puts(seq, ",errors=continue"); |
| 665 | if (nilfs_test_opt(nilfs, STRICT_ORDER)) |
| 666 | seq_puts(seq, ",order=strict"); |
| 667 | if (nilfs_test_opt(nilfs, NORECOVERY)) |
| 668 | seq_puts(seq, ",norecovery"); |
| 669 | if (nilfs_test_opt(nilfs, DISCARD)) |
| 670 | seq_puts(seq, ",discard"); |
| 671 | |
| 672 | return 0; |
| 673 | } |
| 674 | |
| 675 | static const struct super_operations nilfs_sops = { |
| 676 | .alloc_inode = nilfs_alloc_inode, |
| 677 | .destroy_inode = nilfs_destroy_inode, |
| 678 | .dirty_inode = nilfs_dirty_inode, |
| 679 | /* .write_inode = nilfs_write_inode, */ |
| 680 | /* .drop_inode = nilfs_drop_inode, */ |
| 681 | .evict_inode = nilfs_evict_inode, |
| 682 | .put_super = nilfs_put_super, |
| 683 | /* .write_super = nilfs_write_super, */ |
| 684 | .sync_fs = nilfs_sync_fs, |
| 685 | .freeze_fs = nilfs_freeze, |
| 686 | .unfreeze_fs = nilfs_unfreeze, |
| 687 | .statfs = nilfs_statfs, |
| 688 | .remount_fs = nilfs_remount, |
| 689 | /* .umount_begin */ |
| 690 | .show_options = nilfs_show_options |
| 691 | }; |
| 692 | |
| 693 | enum { |
| 694 | Opt_err_cont, Opt_err_panic, Opt_err_ro, |
| 695 | Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery, |
| 696 | Opt_discard, Opt_nodiscard, Opt_err, |
| 697 | }; |
| 698 | |
| 699 | static match_table_t tokens = { |
| 700 | {Opt_err_cont, "errors=continue"}, |
| 701 | {Opt_err_panic, "errors=panic"}, |
| 702 | {Opt_err_ro, "errors=remount-ro"}, |
| 703 | {Opt_barrier, "barrier"}, |
| 704 | {Opt_nobarrier, "nobarrier"}, |
| 705 | {Opt_snapshot, "cp=%u"}, |
| 706 | {Opt_order, "order=%s"}, |
| 707 | {Opt_norecovery, "norecovery"}, |
| 708 | {Opt_discard, "discard"}, |
| 709 | {Opt_nodiscard, "nodiscard"}, |
| 710 | {Opt_err, NULL} |
| 711 | }; |
| 712 | |
| 713 | static int parse_options(char *options, struct super_block *sb, int is_remount) |
| 714 | { |
| 715 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 716 | char *p; |
| 717 | substring_t args[MAX_OPT_ARGS]; |
| 718 | |
| 719 | if (!options) |
| 720 | return 1; |
| 721 | |
| 722 | while ((p = strsep(&options, ",")) != NULL) { |
| 723 | int token; |
| 724 | if (!*p) |
| 725 | continue; |
| 726 | |
| 727 | token = match_token(p, tokens, args); |
| 728 | switch (token) { |
| 729 | case Opt_barrier: |
| 730 | nilfs_set_opt(nilfs, BARRIER); |
| 731 | break; |
| 732 | case Opt_nobarrier: |
| 733 | nilfs_clear_opt(nilfs, BARRIER); |
| 734 | break; |
| 735 | case Opt_order: |
| 736 | if (strcmp(args[0].from, "relaxed") == 0) |
| 737 | /* Ordered data semantics */ |
| 738 | nilfs_clear_opt(nilfs, STRICT_ORDER); |
| 739 | else if (strcmp(args[0].from, "strict") == 0) |
| 740 | /* Strict in-order semantics */ |
| 741 | nilfs_set_opt(nilfs, STRICT_ORDER); |
| 742 | else |
| 743 | return 0; |
| 744 | break; |
| 745 | case Opt_err_panic: |
| 746 | nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC); |
| 747 | break; |
| 748 | case Opt_err_ro: |
| 749 | nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO); |
| 750 | break; |
| 751 | case Opt_err_cont: |
| 752 | nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT); |
| 753 | break; |
| 754 | case Opt_snapshot: |
| 755 | if (is_remount) { |
| 756 | printk(KERN_ERR |
| 757 | "NILFS: \"%s\" option is invalid " |
| 758 | "for remount.\n", p); |
| 759 | return 0; |
| 760 | } |
| 761 | break; |
| 762 | case Opt_norecovery: |
| 763 | nilfs_set_opt(nilfs, NORECOVERY); |
| 764 | break; |
| 765 | case Opt_discard: |
| 766 | nilfs_set_opt(nilfs, DISCARD); |
| 767 | break; |
| 768 | case Opt_nodiscard: |
| 769 | nilfs_clear_opt(nilfs, DISCARD); |
| 770 | break; |
| 771 | default: |
| 772 | printk(KERN_ERR |
| 773 | "NILFS: Unrecognized mount option \"%s\"\n", p); |
| 774 | return 0; |
| 775 | } |
| 776 | } |
| 777 | return 1; |
| 778 | } |
| 779 | |
| 780 | static inline void |
| 781 | nilfs_set_default_options(struct super_block *sb, |
| 782 | struct nilfs_super_block *sbp) |
| 783 | { |
| 784 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 785 | |
| 786 | nilfs->ns_mount_opt = |
| 787 | NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER; |
| 788 | } |
| 789 | |
| 790 | static int nilfs_setup_super(struct super_block *sb, int is_mount) |
| 791 | { |
| 792 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 793 | struct nilfs_super_block **sbp; |
| 794 | int max_mnt_count; |
| 795 | int mnt_count; |
| 796 | |
| 797 | /* nilfs->ns_sem must be locked by the caller. */ |
| 798 | sbp = nilfs_prepare_super(sb, 0); |
| 799 | if (!sbp) |
| 800 | return -EIO; |
| 801 | |
| 802 | if (!is_mount) |
| 803 | goto skip_mount_setup; |
| 804 | |
| 805 | max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count); |
| 806 | mnt_count = le16_to_cpu(sbp[0]->s_mnt_count); |
| 807 | |
| 808 | if (nilfs->ns_mount_state & NILFS_ERROR_FS) { |
| 809 | printk(KERN_WARNING |
| 810 | "NILFS warning: mounting fs with errors\n"); |
| 811 | #if 0 |
| 812 | } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { |
| 813 | printk(KERN_WARNING |
| 814 | "NILFS warning: maximal mount count reached\n"); |
| 815 | #endif |
| 816 | } |
| 817 | if (!max_mnt_count) |
| 818 | sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); |
| 819 | |
| 820 | sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1); |
| 821 | sbp[0]->s_mtime = cpu_to_le64(get_seconds()); |
| 822 | |
| 823 | skip_mount_setup: |
| 824 | sbp[0]->s_state = |
| 825 | cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS); |
| 826 | /* synchronize sbp[1] with sbp[0] */ |
| 827 | if (sbp[1]) |
| 828 | memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); |
| 829 | return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); |
| 830 | } |
| 831 | |
| 832 | struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb, |
| 833 | u64 pos, int blocksize, |
| 834 | struct buffer_head **pbh) |
| 835 | { |
| 836 | unsigned long long sb_index = pos; |
| 837 | unsigned long offset; |
| 838 | |
| 839 | offset = do_div(sb_index, blocksize); |
| 840 | *pbh = sb_bread(sb, sb_index); |
| 841 | if (!*pbh) |
| 842 | return NULL; |
| 843 | return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); |
| 844 | } |
| 845 | |
| 846 | int nilfs_store_magic_and_option(struct super_block *sb, |
| 847 | struct nilfs_super_block *sbp, |
| 848 | char *data) |
| 849 | { |
| 850 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 851 | |
| 852 | sb->s_magic = le16_to_cpu(sbp->s_magic); |
| 853 | |
| 854 | /* FS independent flags */ |
| 855 | #ifdef NILFS_ATIME_DISABLE |
| 856 | sb->s_flags |= MS_NOATIME; |
| 857 | #endif |
| 858 | |
| 859 | nilfs_set_default_options(sb, sbp); |
| 860 | |
| 861 | nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid); |
| 862 | nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid); |
| 863 | nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval); |
| 864 | nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max); |
| 865 | |
| 866 | return !parse_options(data, sb, 0) ? -EINVAL : 0 ; |
| 867 | } |
| 868 | |
| 869 | int nilfs_check_feature_compatibility(struct super_block *sb, |
| 870 | struct nilfs_super_block *sbp) |
| 871 | { |
| 872 | __u64 features; |
| 873 | |
| 874 | features = le64_to_cpu(sbp->s_feature_incompat) & |
| 875 | ~NILFS_FEATURE_INCOMPAT_SUPP; |
| 876 | if (features) { |
| 877 | printk(KERN_ERR "NILFS: couldn't mount because of unsupported " |
| 878 | "optional features (%llx)\n", |
| 879 | (unsigned long long)features); |
| 880 | return -EINVAL; |
| 881 | } |
| 882 | features = le64_to_cpu(sbp->s_feature_compat_ro) & |
| 883 | ~NILFS_FEATURE_COMPAT_RO_SUPP; |
| 884 | if (!(sb->s_flags & MS_RDONLY) && features) { |
| 885 | printk(KERN_ERR "NILFS: couldn't mount RDWR because of " |
| 886 | "unsupported optional features (%llx)\n", |
| 887 | (unsigned long long)features); |
| 888 | return -EINVAL; |
| 889 | } |
| 890 | return 0; |
| 891 | } |
| 892 | |
| 893 | static int nilfs_get_root_dentry(struct super_block *sb, |
| 894 | struct nilfs_root *root, |
| 895 | struct dentry **root_dentry) |
| 896 | { |
| 897 | struct inode *inode; |
| 898 | struct dentry *dentry; |
| 899 | int ret = 0; |
| 900 | |
| 901 | inode = nilfs_iget(sb, root, NILFS_ROOT_INO); |
| 902 | if (IS_ERR(inode)) { |
| 903 | printk(KERN_ERR "NILFS: get root inode failed\n"); |
| 904 | ret = PTR_ERR(inode); |
| 905 | goto out; |
| 906 | } |
| 907 | if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) { |
| 908 | iput(inode); |
| 909 | printk(KERN_ERR "NILFS: corrupt root inode.\n"); |
| 910 | ret = -EINVAL; |
| 911 | goto out; |
| 912 | } |
| 913 | |
| 914 | if (root->cno == NILFS_CPTREE_CURRENT_CNO) { |
| 915 | dentry = d_find_alias(inode); |
| 916 | if (!dentry) { |
| 917 | dentry = d_make_root(inode); |
| 918 | if (!dentry) { |
| 919 | ret = -ENOMEM; |
| 920 | goto failed_dentry; |
| 921 | } |
| 922 | } else { |
| 923 | iput(inode); |
| 924 | } |
| 925 | } else { |
| 926 | dentry = d_obtain_alias(inode); |
| 927 | if (IS_ERR(dentry)) { |
| 928 | ret = PTR_ERR(dentry); |
| 929 | goto failed_dentry; |
| 930 | } |
| 931 | } |
| 932 | *root_dentry = dentry; |
| 933 | out: |
| 934 | return ret; |
| 935 | |
| 936 | failed_dentry: |
| 937 | printk(KERN_ERR "NILFS: get root dentry failed\n"); |
| 938 | goto out; |
| 939 | } |
| 940 | |
| 941 | static int nilfs_attach_snapshot(struct super_block *s, __u64 cno, |
| 942 | struct dentry **root_dentry) |
| 943 | { |
| 944 | struct the_nilfs *nilfs = s->s_fs_info; |
| 945 | struct nilfs_root *root; |
| 946 | int ret; |
| 947 | |
| 948 | mutex_lock(&nilfs->ns_snapshot_mount_mutex); |
| 949 | |
| 950 | down_read(&nilfs->ns_segctor_sem); |
| 951 | ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno); |
| 952 | up_read(&nilfs->ns_segctor_sem); |
| 953 | if (ret < 0) { |
| 954 | ret = (ret == -ENOENT) ? -EINVAL : ret; |
| 955 | goto out; |
| 956 | } else if (!ret) { |
| 957 | printk(KERN_ERR "NILFS: The specified checkpoint is " |
| 958 | "not a snapshot (checkpoint number=%llu).\n", |
| 959 | (unsigned long long)cno); |
| 960 | ret = -EINVAL; |
| 961 | goto out; |
| 962 | } |
| 963 | |
| 964 | ret = nilfs_attach_checkpoint(s, cno, false, &root); |
| 965 | if (ret) { |
| 966 | printk(KERN_ERR "NILFS: error loading snapshot " |
| 967 | "(checkpoint number=%llu).\n", |
| 968 | (unsigned long long)cno); |
| 969 | goto out; |
| 970 | } |
| 971 | ret = nilfs_get_root_dentry(s, root, root_dentry); |
| 972 | nilfs_put_root(root); |
| 973 | out: |
| 974 | mutex_unlock(&nilfs->ns_snapshot_mount_mutex); |
| 975 | return ret; |
| 976 | } |
| 977 | |
| 978 | static int nilfs_tree_was_touched(struct dentry *root_dentry) |
| 979 | { |
| 980 | return root_dentry->d_count > 1; |
| 981 | } |
| 982 | |
| 983 | /** |
| 984 | * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint |
| 985 | * @root_dentry: root dentry of the tree to be shrunk |
| 986 | * |
| 987 | * This function returns true if the tree was in-use. |
| 988 | */ |
| 989 | static int nilfs_try_to_shrink_tree(struct dentry *root_dentry) |
| 990 | { |
| 991 | if (have_submounts(root_dentry)) |
| 992 | return true; |
| 993 | shrink_dcache_parent(root_dentry); |
| 994 | return nilfs_tree_was_touched(root_dentry); |
| 995 | } |
| 996 | |
| 997 | int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno) |
| 998 | { |
| 999 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 1000 | struct nilfs_root *root; |
| 1001 | struct inode *inode; |
| 1002 | struct dentry *dentry; |
| 1003 | int ret; |
| 1004 | |
| 1005 | if (cno < 0 || cno > nilfs->ns_cno) |
| 1006 | return false; |
| 1007 | |
| 1008 | if (cno >= nilfs_last_cno(nilfs)) |
| 1009 | return true; /* protect recent checkpoints */ |
| 1010 | |
| 1011 | ret = false; |
| 1012 | root = nilfs_lookup_root(nilfs, cno); |
| 1013 | if (root) { |
| 1014 | inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO); |
| 1015 | if (inode) { |
| 1016 | dentry = d_find_alias(inode); |
| 1017 | if (dentry) { |
| 1018 | if (nilfs_tree_was_touched(dentry)) |
| 1019 | ret = nilfs_try_to_shrink_tree(dentry); |
| 1020 | dput(dentry); |
| 1021 | } |
| 1022 | iput(inode); |
| 1023 | } |
| 1024 | nilfs_put_root(root); |
| 1025 | } |
| 1026 | return ret; |
| 1027 | } |
| 1028 | |
| 1029 | /** |
| 1030 | * nilfs_fill_super() - initialize a super block instance |
| 1031 | * @sb: super_block |
| 1032 | * @data: mount options |
| 1033 | * @silent: silent mode flag |
| 1034 | * |
| 1035 | * This function is called exclusively by nilfs->ns_mount_mutex. |
| 1036 | * So, the recovery process is protected from other simultaneous mounts. |
| 1037 | */ |
| 1038 | static int |
| 1039 | nilfs_fill_super(struct super_block *sb, void *data, int silent) |
| 1040 | { |
| 1041 | struct the_nilfs *nilfs; |
| 1042 | struct nilfs_root *fsroot; |
| 1043 | struct backing_dev_info *bdi; |
| 1044 | __u64 cno; |
| 1045 | int err; |
| 1046 | |
| 1047 | nilfs = alloc_nilfs(sb->s_bdev); |
| 1048 | if (!nilfs) |
| 1049 | return -ENOMEM; |
| 1050 | |
| 1051 | sb->s_fs_info = nilfs; |
| 1052 | |
| 1053 | err = init_nilfs(nilfs, sb, (char *)data); |
| 1054 | if (err) |
| 1055 | goto failed_nilfs; |
| 1056 | |
| 1057 | sb->s_op = &nilfs_sops; |
| 1058 | sb->s_export_op = &nilfs_export_ops; |
| 1059 | sb->s_root = NULL; |
| 1060 | sb->s_time_gran = 1; |
| 1061 | sb->s_max_links = NILFS_LINK_MAX; |
| 1062 | |
| 1063 | bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; |
| 1064 | sb->s_bdi = bdi ? : &default_backing_dev_info; |
| 1065 | |
| 1066 | err = load_nilfs(nilfs, sb); |
| 1067 | if (err) |
| 1068 | goto failed_nilfs; |
| 1069 | |
| 1070 | cno = nilfs_last_cno(nilfs); |
| 1071 | err = nilfs_attach_checkpoint(sb, cno, true, &fsroot); |
| 1072 | if (err) { |
| 1073 | printk(KERN_ERR "NILFS: error loading last checkpoint " |
| 1074 | "(checkpoint number=%llu).\n", (unsigned long long)cno); |
| 1075 | goto failed_unload; |
| 1076 | } |
| 1077 | |
| 1078 | if (!(sb->s_flags & MS_RDONLY)) { |
| 1079 | err = nilfs_attach_log_writer(sb, fsroot); |
| 1080 | if (err) |
| 1081 | goto failed_checkpoint; |
| 1082 | } |
| 1083 | |
| 1084 | err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root); |
| 1085 | if (err) |
| 1086 | goto failed_segctor; |
| 1087 | |
| 1088 | nilfs_put_root(fsroot); |
| 1089 | |
| 1090 | if (!(sb->s_flags & MS_RDONLY)) { |
| 1091 | down_write(&nilfs->ns_sem); |
| 1092 | nilfs_setup_super(sb, true); |
| 1093 | up_write(&nilfs->ns_sem); |
| 1094 | } |
| 1095 | |
| 1096 | return 0; |
| 1097 | |
| 1098 | failed_segctor: |
| 1099 | nilfs_detach_log_writer(sb); |
| 1100 | |
| 1101 | failed_checkpoint: |
| 1102 | nilfs_put_root(fsroot); |
| 1103 | |
| 1104 | failed_unload: |
| 1105 | iput(nilfs->ns_sufile); |
| 1106 | iput(nilfs->ns_cpfile); |
| 1107 | iput(nilfs->ns_dat); |
| 1108 | |
| 1109 | failed_nilfs: |
| 1110 | destroy_nilfs(nilfs); |
| 1111 | return err; |
| 1112 | } |
| 1113 | |
| 1114 | static int nilfs_remount(struct super_block *sb, int *flags, char *data) |
| 1115 | { |
| 1116 | struct the_nilfs *nilfs = sb->s_fs_info; |
| 1117 | unsigned long old_sb_flags; |
| 1118 | unsigned long old_mount_opt; |
| 1119 | int err; |
| 1120 | |
| 1121 | old_sb_flags = sb->s_flags; |
| 1122 | old_mount_opt = nilfs->ns_mount_opt; |
| 1123 | |
| 1124 | if (!parse_options(data, sb, 1)) { |
| 1125 | err = -EINVAL; |
| 1126 | goto restore_opts; |
| 1127 | } |
| 1128 | sb->s_flags = (sb->s_flags & ~MS_POSIXACL); |
| 1129 | |
| 1130 | err = -EINVAL; |
| 1131 | |
| 1132 | if (!nilfs_valid_fs(nilfs)) { |
| 1133 | printk(KERN_WARNING "NILFS (device %s): couldn't " |
| 1134 | "remount because the filesystem is in an " |
| 1135 | "incomplete recovery state.\n", sb->s_id); |
| 1136 | goto restore_opts; |
| 1137 | } |
| 1138 | |
| 1139 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) |
| 1140 | goto out; |
| 1141 | if (*flags & MS_RDONLY) { |
| 1142 | /* Shutting down log writer */ |
| 1143 | nilfs_detach_log_writer(sb); |
| 1144 | sb->s_flags |= MS_RDONLY; |
| 1145 | |
| 1146 | /* |
| 1147 | * Remounting a valid RW partition RDONLY, so set |
| 1148 | * the RDONLY flag and then mark the partition as valid again. |
| 1149 | */ |
| 1150 | down_write(&nilfs->ns_sem); |
| 1151 | nilfs_cleanup_super(sb); |
| 1152 | up_write(&nilfs->ns_sem); |
| 1153 | } else { |
| 1154 | __u64 features; |
| 1155 | struct nilfs_root *root; |
| 1156 | |
| 1157 | /* |
| 1158 | * Mounting a RDONLY partition read-write, so reread and |
| 1159 | * store the current valid flag. (It may have been changed |
| 1160 | * by fsck since we originally mounted the partition.) |
| 1161 | */ |
| 1162 | down_read(&nilfs->ns_sem); |
| 1163 | features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & |
| 1164 | ~NILFS_FEATURE_COMPAT_RO_SUPP; |
| 1165 | up_read(&nilfs->ns_sem); |
| 1166 | if (features) { |
| 1167 | printk(KERN_WARNING "NILFS (device %s): couldn't " |
| 1168 | "remount RDWR because of unsupported optional " |
| 1169 | "features (%llx)\n", |
| 1170 | sb->s_id, (unsigned long long)features); |
| 1171 | err = -EROFS; |
| 1172 | goto restore_opts; |
| 1173 | } |
| 1174 | |
| 1175 | sb->s_flags &= ~MS_RDONLY; |
| 1176 | |
| 1177 | root = NILFS_I(sb->s_root->d_inode)->i_root; |
| 1178 | err = nilfs_attach_log_writer(sb, root); |
| 1179 | if (err) |
| 1180 | goto restore_opts; |
| 1181 | |
| 1182 | down_write(&nilfs->ns_sem); |
| 1183 | nilfs_setup_super(sb, true); |
| 1184 | up_write(&nilfs->ns_sem); |
| 1185 | } |
| 1186 | out: |
| 1187 | return 0; |
| 1188 | |
| 1189 | restore_opts: |
| 1190 | sb->s_flags = old_sb_flags; |
| 1191 | nilfs->ns_mount_opt = old_mount_opt; |
| 1192 | return err; |
| 1193 | } |
| 1194 | |
| 1195 | struct nilfs_super_data { |
| 1196 | struct block_device *bdev; |
| 1197 | __u64 cno; |
| 1198 | int flags; |
| 1199 | }; |
| 1200 | |
| 1201 | /** |
| 1202 | * nilfs_identify - pre-read mount options needed to identify mount instance |
| 1203 | * @data: mount options |
| 1204 | * @sd: nilfs_super_data |
| 1205 | */ |
| 1206 | static int nilfs_identify(char *data, struct nilfs_super_data *sd) |
| 1207 | { |
| 1208 | char *p, *options = data; |
| 1209 | substring_t args[MAX_OPT_ARGS]; |
| 1210 | int token; |
| 1211 | int ret = 0; |
| 1212 | |
| 1213 | do { |
| 1214 | p = strsep(&options, ","); |
| 1215 | if (p != NULL && *p) { |
| 1216 | token = match_token(p, tokens, args); |
| 1217 | if (token == Opt_snapshot) { |
| 1218 | if (!(sd->flags & MS_RDONLY)) { |
| 1219 | ret++; |
| 1220 | } else { |
| 1221 | sd->cno = simple_strtoull(args[0].from, |
| 1222 | NULL, 0); |
| 1223 | /* |
| 1224 | * No need to see the end pointer; |
| 1225 | * match_token() has done syntax |
| 1226 | * checking. |
| 1227 | */ |
| 1228 | if (sd->cno == 0) |
| 1229 | ret++; |
| 1230 | } |
| 1231 | } |
| 1232 | if (ret) |
| 1233 | printk(KERN_ERR |
| 1234 | "NILFS: invalid mount option: %s\n", p); |
| 1235 | } |
| 1236 | if (!options) |
| 1237 | break; |
| 1238 | BUG_ON(options == data); |
| 1239 | *(options - 1) = ','; |
| 1240 | } while (!ret); |
| 1241 | return ret; |
| 1242 | } |
| 1243 | |
| 1244 | static int nilfs_set_bdev_super(struct super_block *s, void *data) |
| 1245 | { |
| 1246 | s->s_bdev = data; |
| 1247 | s->s_dev = s->s_bdev->bd_dev; |
| 1248 | return 0; |
| 1249 | } |
| 1250 | |
| 1251 | static int nilfs_test_bdev_super(struct super_block *s, void *data) |
| 1252 | { |
| 1253 | return (void *)s->s_bdev == data; |
| 1254 | } |
| 1255 | |
| 1256 | static struct dentry * |
| 1257 | nilfs_mount(struct file_system_type *fs_type, int flags, |
| 1258 | const char *dev_name, void *data) |
| 1259 | { |
| 1260 | struct nilfs_super_data sd; |
| 1261 | struct super_block *s; |
| 1262 | fmode_t mode = FMODE_READ | FMODE_EXCL; |
| 1263 | struct dentry *root_dentry; |
| 1264 | int err, s_new = false; |
| 1265 | |
| 1266 | if (!(flags & MS_RDONLY)) |
| 1267 | mode |= FMODE_WRITE; |
| 1268 | |
| 1269 | sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type); |
| 1270 | if (IS_ERR(sd.bdev)) |
| 1271 | return ERR_CAST(sd.bdev); |
| 1272 | |
| 1273 | sd.cno = 0; |
| 1274 | sd.flags = flags; |
| 1275 | if (nilfs_identify((char *)data, &sd)) { |
| 1276 | err = -EINVAL; |
| 1277 | goto failed; |
| 1278 | } |
| 1279 | |
| 1280 | /* |
| 1281 | * once the super is inserted into the list by sget, s_umount |
| 1282 | * will protect the lockfs code from trying to start a snapshot |
| 1283 | * while we are mounting |
| 1284 | */ |
| 1285 | mutex_lock(&sd.bdev->bd_fsfreeze_mutex); |
| 1286 | if (sd.bdev->bd_fsfreeze_count > 0) { |
| 1287 | mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); |
| 1288 | err = -EBUSY; |
| 1289 | goto failed; |
| 1290 | } |
| 1291 | s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags, |
| 1292 | sd.bdev); |
| 1293 | mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); |
| 1294 | if (IS_ERR(s)) { |
| 1295 | err = PTR_ERR(s); |
| 1296 | goto failed; |
| 1297 | } |
| 1298 | |
| 1299 | if (!s->s_root) { |
| 1300 | char b[BDEVNAME_SIZE]; |
| 1301 | |
| 1302 | s_new = true; |
| 1303 | |
| 1304 | /* New superblock instance created */ |
| 1305 | s->s_mode = mode; |
| 1306 | strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); |
| 1307 | sb_set_blocksize(s, block_size(sd.bdev)); |
| 1308 | |
| 1309 | err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0); |
| 1310 | if (err) |
| 1311 | goto failed_super; |
| 1312 | |
| 1313 | s->s_flags |= MS_ACTIVE; |
| 1314 | } else if (!sd.cno) { |
| 1315 | int busy = false; |
| 1316 | |
| 1317 | if (nilfs_tree_was_touched(s->s_root)) { |
| 1318 | busy = nilfs_try_to_shrink_tree(s->s_root); |
| 1319 | if (busy && (flags ^ s->s_flags) & MS_RDONLY) { |
| 1320 | printk(KERN_ERR "NILFS: the device already " |
| 1321 | "has a %s mount.\n", |
| 1322 | (s->s_flags & MS_RDONLY) ? |
| 1323 | "read-only" : "read/write"); |
| 1324 | err = -EBUSY; |
| 1325 | goto failed_super; |
| 1326 | } |
| 1327 | } |
| 1328 | if (!busy) { |
| 1329 | /* |
| 1330 | * Try remount to setup mount states if the current |
| 1331 | * tree is not mounted and only snapshots use this sb. |
| 1332 | */ |
| 1333 | err = nilfs_remount(s, &flags, data); |
| 1334 | if (err) |
| 1335 | goto failed_super; |
| 1336 | } |
| 1337 | } |
| 1338 | |
| 1339 | if (sd.cno) { |
| 1340 | err = nilfs_attach_snapshot(s, sd.cno, &root_dentry); |
| 1341 | if (err) |
| 1342 | goto failed_super; |
| 1343 | } else { |
| 1344 | root_dentry = dget(s->s_root); |
| 1345 | } |
| 1346 | |
| 1347 | if (!s_new) |
| 1348 | blkdev_put(sd.bdev, mode); |
| 1349 | |
| 1350 | return root_dentry; |
| 1351 | |
| 1352 | failed_super: |
| 1353 | deactivate_locked_super(s); |
| 1354 | |
| 1355 | failed: |
| 1356 | if (!s_new) |
| 1357 | blkdev_put(sd.bdev, mode); |
| 1358 | return ERR_PTR(err); |
| 1359 | } |
| 1360 | |
| 1361 | struct file_system_type nilfs_fs_type = { |
| 1362 | .owner = THIS_MODULE, |
| 1363 | .name = "nilfs2", |
| 1364 | .mount = nilfs_mount, |
| 1365 | .kill_sb = kill_block_super, |
| 1366 | .fs_flags = FS_REQUIRES_DEV, |
| 1367 | }; |
| 1368 | |
| 1369 | static void nilfs_inode_init_once(void *obj) |
| 1370 | { |
| 1371 | struct nilfs_inode_info *ii = obj; |
| 1372 | |
| 1373 | INIT_LIST_HEAD(&ii->i_dirty); |
| 1374 | #ifdef CONFIG_NILFS_XATTR |
| 1375 | init_rwsem(&ii->xattr_sem); |
| 1376 | #endif |
| 1377 | address_space_init_once(&ii->i_btnode_cache); |
| 1378 | ii->i_bmap = &ii->i_bmap_data; |
| 1379 | inode_init_once(&ii->vfs_inode); |
| 1380 | } |
| 1381 | |
| 1382 | static void nilfs_segbuf_init_once(void *obj) |
| 1383 | { |
| 1384 | memset(obj, 0, sizeof(struct nilfs_segment_buffer)); |
| 1385 | } |
| 1386 | |
| 1387 | static void nilfs_destroy_cachep(void) |
| 1388 | { |
| 1389 | if (nilfs_inode_cachep) |
| 1390 | kmem_cache_destroy(nilfs_inode_cachep); |
| 1391 | if (nilfs_transaction_cachep) |
| 1392 | kmem_cache_destroy(nilfs_transaction_cachep); |
| 1393 | if (nilfs_segbuf_cachep) |
| 1394 | kmem_cache_destroy(nilfs_segbuf_cachep); |
| 1395 | if (nilfs_btree_path_cache) |
| 1396 | kmem_cache_destroy(nilfs_btree_path_cache); |
| 1397 | } |
| 1398 | |
| 1399 | static int __init nilfs_init_cachep(void) |
| 1400 | { |
| 1401 | nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", |
| 1402 | sizeof(struct nilfs_inode_info), 0, |
| 1403 | SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once); |
| 1404 | if (!nilfs_inode_cachep) |
| 1405 | goto fail; |
| 1406 | |
| 1407 | nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache", |
| 1408 | sizeof(struct nilfs_transaction_info), 0, |
| 1409 | SLAB_RECLAIM_ACCOUNT, NULL); |
| 1410 | if (!nilfs_transaction_cachep) |
| 1411 | goto fail; |
| 1412 | |
| 1413 | nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache", |
| 1414 | sizeof(struct nilfs_segment_buffer), 0, |
| 1415 | SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once); |
| 1416 | if (!nilfs_segbuf_cachep) |
| 1417 | goto fail; |
| 1418 | |
| 1419 | nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache", |
| 1420 | sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX, |
| 1421 | 0, 0, NULL); |
| 1422 | if (!nilfs_btree_path_cache) |
| 1423 | goto fail; |
| 1424 | |
| 1425 | return 0; |
| 1426 | |
| 1427 | fail: |
| 1428 | nilfs_destroy_cachep(); |
| 1429 | return -ENOMEM; |
| 1430 | } |
| 1431 | |
| 1432 | static int __init init_nilfs_fs(void) |
| 1433 | { |
| 1434 | int err; |
| 1435 | |
| 1436 | err = nilfs_init_cachep(); |
| 1437 | if (err) |
| 1438 | goto fail; |
| 1439 | |
| 1440 | err = register_filesystem(&nilfs_fs_type); |
| 1441 | if (err) |
| 1442 | goto free_cachep; |
| 1443 | |
| 1444 | printk(KERN_INFO "NILFS version 2 loaded\n"); |
| 1445 | return 0; |
| 1446 | |
| 1447 | free_cachep: |
| 1448 | nilfs_destroy_cachep(); |
| 1449 | fail: |
| 1450 | return err; |
| 1451 | } |
| 1452 | |
| 1453 | static void __exit exit_nilfs_fs(void) |
| 1454 | { |
| 1455 | nilfs_destroy_cachep(); |
| 1456 | unregister_filesystem(&nilfs_fs_type); |
| 1457 | } |
| 1458 | |
| 1459 | module_init(init_nilfs_fs) |
| 1460 | module_exit(exit_nilfs_fs) |