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 * Written by Ryusuke Konishi. 17 */ 18 /* 19 * linux/fs/ext2/super.c 20 * 21 * Copyright (C) 1992, 1993, 1994, 1995 22 * Remy Card (card@masi.ibp.fr) 23 * Laboratoire MASI - Institut Blaise Pascal 24 * Universite Pierre et Marie Curie (Paris VI) 25 * 26 * from 27 * 28 * linux/fs/minix/inode.c 29 * 30 * Copyright (C) 1991, 1992 Linus Torvalds 31 * 32 * Big-endian to little-endian byte-swapping/bitmaps by 33 * David S. Miller (davem@caip.rutgers.edu), 1995 34 */ 35 36 #include <linux/module.h> 37 #include <linux/string.h> 38 #include <linux/slab.h> 39 #include <linux/init.h> 40 #include <linux/blkdev.h> 41 #include <linux/parser.h> 42 #include <linux/crc32.h> 43 #include <linux/vfs.h> 44 #include <linux/writeback.h> 45 #include <linux/seq_file.h> 46 #include <linux/mount.h> 47 #include "nilfs.h" 48 #include "export.h" 49 #include "mdt.h" 50 #include "alloc.h" 51 #include "btree.h" 52 #include "btnode.h" 53 #include "page.h" 54 #include "cpfile.h" 55 #include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */ 56 #include "ifile.h" 57 #include "dat.h" 58 #include "segment.h" 59 #include "segbuf.h" 60 61 MODULE_AUTHOR("NTT Corp."); 62 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem " 63 "(NILFS)"); 64 MODULE_LICENSE("GPL"); 65 66 static struct kmem_cache *nilfs_inode_cachep; 67 struct kmem_cache *nilfs_transaction_cachep; 68 struct kmem_cache *nilfs_segbuf_cachep; 69 struct kmem_cache *nilfs_btree_path_cache; 70 71 static int nilfs_setup_super(struct super_block *sb, int is_mount); 72 static int nilfs_remount(struct super_block *sb, int *flags, char *data); 73 74 void __nilfs_msg(struct super_block *sb, const char *level, const char *fmt, 75 ...) 76 { 77 struct va_format vaf; 78 va_list args; 79 80 va_start(args, fmt); 81 vaf.fmt = fmt; 82 vaf.va = &args; 83 if (sb) 84 printk("%sNILFS (%s): %pV\n", level, sb->s_id, &vaf); 85 else 86 printk("%sNILFS: %pV\n", level, &vaf); 87 va_end(args); 88 } 89 90 static void nilfs_set_error(struct super_block *sb) 91 { 92 struct the_nilfs *nilfs = sb->s_fs_info; 93 struct nilfs_super_block **sbp; 94 95 down_write(&nilfs->ns_sem); 96 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { 97 nilfs->ns_mount_state |= NILFS_ERROR_FS; 98 sbp = nilfs_prepare_super(sb, 0); 99 if (likely(sbp)) { 100 sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS); 101 if (sbp[1]) 102 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS); 103 nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); 104 } 105 } 106 up_write(&nilfs->ns_sem); 107 } 108 109 /** 110 * __nilfs_error() - report failure condition on a filesystem 111 * 112 * __nilfs_error() sets an ERROR_FS flag on the superblock as well as 113 * reporting an error message. This function should be called when 114 * NILFS detects incoherences or defects of meta data on disk. 115 * 116 * This implements the body of nilfs_error() macro. Normally, 117 * nilfs_error() should be used. As for sustainable errors such as a 118 * single-shot I/O error, nilfs_msg() should be used instead. 119 * 120 * Callers should not add a trailing newline since this will do it. 121 */ 122 void __nilfs_error(struct super_block *sb, const char *function, 123 const char *fmt, ...) 124 { 125 struct the_nilfs *nilfs = sb->s_fs_info; 126 struct va_format vaf; 127 va_list args; 128 129 va_start(args, fmt); 130 131 vaf.fmt = fmt; 132 vaf.va = &args; 133 134 printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n", 135 sb->s_id, function, &vaf); 136 137 va_end(args); 138 139 if (!sb_rdonly(sb)) { 140 nilfs_set_error(sb); 141 142 if (nilfs_test_opt(nilfs, ERRORS_RO)) { 143 printk(KERN_CRIT "Remounting filesystem read-only\n"); 144 sb->s_flags |= MS_RDONLY; 145 } 146 } 147 148 if (nilfs_test_opt(nilfs, ERRORS_PANIC)) 149 panic("NILFS (device %s): panic forced after error\n", 150 sb->s_id); 151 } 152 153 struct inode *nilfs_alloc_inode(struct super_block *sb) 154 { 155 struct nilfs_inode_info *ii; 156 157 ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS); 158 if (!ii) 159 return NULL; 160 ii->i_bh = NULL; 161 ii->i_state = 0; 162 ii->i_cno = 0; 163 ii->vfs_inode.i_version = 1; 164 nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode); 165 return &ii->vfs_inode; 166 } 167 168 static void nilfs_i_callback(struct rcu_head *head) 169 { 170 struct inode *inode = container_of(head, struct inode, i_rcu); 171 172 if (nilfs_is_metadata_file_inode(inode)) 173 nilfs_mdt_destroy(inode); 174 175 kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); 176 } 177 178 void nilfs_destroy_inode(struct inode *inode) 179 { 180 call_rcu(&inode->i_rcu, nilfs_i_callback); 181 } 182 183 static int nilfs_sync_super(struct super_block *sb, int flag) 184 { 185 struct the_nilfs *nilfs = sb->s_fs_info; 186 int err; 187 188 retry: 189 set_buffer_dirty(nilfs->ns_sbh[0]); 190 if (nilfs_test_opt(nilfs, BARRIER)) { 191 err = __sync_dirty_buffer(nilfs->ns_sbh[0], 192 REQ_SYNC | REQ_PREFLUSH | REQ_FUA); 193 } else { 194 err = sync_dirty_buffer(nilfs->ns_sbh[0]); 195 } 196 197 if (unlikely(err)) { 198 nilfs_msg(sb, KERN_ERR, "unable to write superblock: err=%d", 199 err); 200 if (err == -EIO && nilfs->ns_sbh[1]) { 201 /* 202 * sbp[0] points to newer log than sbp[1], 203 * so copy sbp[0] to sbp[1] to take over sbp[0]. 204 */ 205 memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0], 206 nilfs->ns_sbsize); 207 nilfs_fall_back_super_block(nilfs); 208 goto retry; 209 } 210 } else { 211 struct nilfs_super_block *sbp = nilfs->ns_sbp[0]; 212 213 nilfs->ns_sbwcount++; 214 215 /* 216 * The latest segment becomes trailable from the position 217 * written in superblock. 218 */ 219 clear_nilfs_discontinued(nilfs); 220 221 /* update GC protection for recent segments */ 222 if (nilfs->ns_sbh[1]) { 223 if (flag == NILFS_SB_COMMIT_ALL) { 224 set_buffer_dirty(nilfs->ns_sbh[1]); 225 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0) 226 goto out; 227 } 228 if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) < 229 le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno)) 230 sbp = nilfs->ns_sbp[1]; 231 } 232 233 spin_lock(&nilfs->ns_last_segment_lock); 234 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq); 235 spin_unlock(&nilfs->ns_last_segment_lock); 236 } 237 out: 238 return err; 239 } 240 241 void nilfs_set_log_cursor(struct nilfs_super_block *sbp, 242 struct the_nilfs *nilfs) 243 { 244 sector_t nfreeblocks; 245 246 /* nilfs->ns_sem must be locked by the caller. */ 247 nilfs_count_free_blocks(nilfs, &nfreeblocks); 248 sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks); 249 250 spin_lock(&nilfs->ns_last_segment_lock); 251 sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq); 252 sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg); 253 sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno); 254 spin_unlock(&nilfs->ns_last_segment_lock); 255 } 256 257 struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb, 258 int flip) 259 { 260 struct the_nilfs *nilfs = sb->s_fs_info; 261 struct nilfs_super_block **sbp = nilfs->ns_sbp; 262 263 /* nilfs->ns_sem must be locked by the caller. */ 264 if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { 265 if (sbp[1] && 266 sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) { 267 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 268 } else { 269 nilfs_msg(sb, KERN_CRIT, "superblock broke"); 270 return NULL; 271 } 272 } else if (sbp[1] && 273 sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) { 274 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); 275 } 276 277 if (flip && sbp[1]) 278 nilfs_swap_super_block(nilfs); 279 280 return sbp; 281 } 282 283 int nilfs_commit_super(struct super_block *sb, int flag) 284 { 285 struct the_nilfs *nilfs = sb->s_fs_info; 286 struct nilfs_super_block **sbp = nilfs->ns_sbp; 287 time_t t; 288 289 /* nilfs->ns_sem must be locked by the caller. */ 290 t = get_seconds(); 291 nilfs->ns_sbwtime = t; 292 sbp[0]->s_wtime = cpu_to_le64(t); 293 sbp[0]->s_sum = 0; 294 sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, 295 (unsigned char *)sbp[0], 296 nilfs->ns_sbsize)); 297 if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) { 298 sbp[1]->s_wtime = sbp[0]->s_wtime; 299 sbp[1]->s_sum = 0; 300 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed, 301 (unsigned char *)sbp[1], 302 nilfs->ns_sbsize)); 303 } 304 clear_nilfs_sb_dirty(nilfs); 305 nilfs->ns_flushed_device = 1; 306 /* make sure store to ns_flushed_device cannot be reordered */ 307 smp_wmb(); 308 return nilfs_sync_super(sb, flag); 309 } 310 311 /** 312 * nilfs_cleanup_super() - write filesystem state for cleanup 313 * @sb: super block instance to be unmounted or degraded to read-only 314 * 315 * This function restores state flags in the on-disk super block. 316 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the 317 * filesystem was not clean previously. 318 */ 319 int nilfs_cleanup_super(struct super_block *sb) 320 { 321 struct the_nilfs *nilfs = sb->s_fs_info; 322 struct nilfs_super_block **sbp; 323 int flag = NILFS_SB_COMMIT; 324 int ret = -EIO; 325 326 sbp = nilfs_prepare_super(sb, 0); 327 if (sbp) { 328 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state); 329 nilfs_set_log_cursor(sbp[0], nilfs); 330 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) { 331 /* 332 * make the "clean" flag also to the opposite 333 * super block if both super blocks point to 334 * the same checkpoint. 335 */ 336 sbp[1]->s_state = sbp[0]->s_state; 337 flag = NILFS_SB_COMMIT_ALL; 338 } 339 ret = nilfs_commit_super(sb, flag); 340 } 341 return ret; 342 } 343 344 /** 345 * nilfs_move_2nd_super - relocate secondary super block 346 * @sb: super block instance 347 * @sb2off: new offset of the secondary super block (in bytes) 348 */ 349 static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off) 350 { 351 struct the_nilfs *nilfs = sb->s_fs_info; 352 struct buffer_head *nsbh; 353 struct nilfs_super_block *nsbp; 354 sector_t blocknr, newblocknr; 355 unsigned long offset; 356 int sb2i; /* array index of the secondary superblock */ 357 int ret = 0; 358 359 /* nilfs->ns_sem must be locked by the caller. */ 360 if (nilfs->ns_sbh[1] && 361 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) { 362 sb2i = 1; 363 blocknr = nilfs->ns_sbh[1]->b_blocknr; 364 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) { 365 sb2i = 0; 366 blocknr = nilfs->ns_sbh[0]->b_blocknr; 367 } else { 368 sb2i = -1; 369 blocknr = 0; 370 } 371 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off) 372 goto out; /* super block location is unchanged */ 373 374 /* Get new super block buffer */ 375 newblocknr = sb2off >> nilfs->ns_blocksize_bits; 376 offset = sb2off & (nilfs->ns_blocksize - 1); 377 nsbh = sb_getblk(sb, newblocknr); 378 if (!nsbh) { 379 nilfs_msg(sb, KERN_WARNING, 380 "unable to move secondary superblock to block %llu", 381 (unsigned long long)newblocknr); 382 ret = -EIO; 383 goto out; 384 } 385 nsbp = (void *)nsbh->b_data + offset; 386 memset(nsbp, 0, nilfs->ns_blocksize); 387 388 if (sb2i >= 0) { 389 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize); 390 brelse(nilfs->ns_sbh[sb2i]); 391 nilfs->ns_sbh[sb2i] = nsbh; 392 nilfs->ns_sbp[sb2i] = nsbp; 393 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) { 394 /* secondary super block will be restored to index 1 */ 395 nilfs->ns_sbh[1] = nsbh; 396 nilfs->ns_sbp[1] = nsbp; 397 } else { 398 brelse(nsbh); 399 } 400 out: 401 return ret; 402 } 403 404 /** 405 * nilfs_resize_fs - resize the filesystem 406 * @sb: super block instance 407 * @newsize: new size of the filesystem (in bytes) 408 */ 409 int nilfs_resize_fs(struct super_block *sb, __u64 newsize) 410 { 411 struct the_nilfs *nilfs = sb->s_fs_info; 412 struct nilfs_super_block **sbp; 413 __u64 devsize, newnsegs; 414 loff_t sb2off; 415 int ret; 416 417 ret = -ERANGE; 418 devsize = i_size_read(sb->s_bdev->bd_inode); 419 if (newsize > devsize) 420 goto out; 421 422 /* 423 * Write lock is required to protect some functions depending 424 * on the number of segments, the number of reserved segments, 425 * and so forth. 426 */ 427 down_write(&nilfs->ns_segctor_sem); 428 429 sb2off = NILFS_SB2_OFFSET_BYTES(newsize); 430 newnsegs = sb2off >> nilfs->ns_blocksize_bits; 431 do_div(newnsegs, nilfs->ns_blocks_per_segment); 432 433 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs); 434 up_write(&nilfs->ns_segctor_sem); 435 if (ret < 0) 436 goto out; 437 438 ret = nilfs_construct_segment(sb); 439 if (ret < 0) 440 goto out; 441 442 down_write(&nilfs->ns_sem); 443 nilfs_move_2nd_super(sb, sb2off); 444 ret = -EIO; 445 sbp = nilfs_prepare_super(sb, 0); 446 if (likely(sbp)) { 447 nilfs_set_log_cursor(sbp[0], nilfs); 448 /* 449 * Drop NILFS_RESIZE_FS flag for compatibility with 450 * mount-time resize which may be implemented in a 451 * future release. 452 */ 453 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & 454 ~NILFS_RESIZE_FS); 455 sbp[0]->s_dev_size = cpu_to_le64(newsize); 456 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments); 457 if (sbp[1]) 458 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); 459 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); 460 } 461 up_write(&nilfs->ns_sem); 462 463 /* 464 * Reset the range of allocatable segments last. This order 465 * is important in the case of expansion because the secondary 466 * superblock must be protected from log write until migration 467 * completes. 468 */ 469 if (!ret) 470 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1); 471 out: 472 return ret; 473 } 474 475 static void nilfs_put_super(struct super_block *sb) 476 { 477 struct the_nilfs *nilfs = sb->s_fs_info; 478 479 nilfs_detach_log_writer(sb); 480 481 if (!sb_rdonly(sb)) { 482 down_write(&nilfs->ns_sem); 483 nilfs_cleanup_super(sb); 484 up_write(&nilfs->ns_sem); 485 } 486 487 iput(nilfs->ns_sufile); 488 iput(nilfs->ns_cpfile); 489 iput(nilfs->ns_dat); 490 491 destroy_nilfs(nilfs); 492 sb->s_fs_info = NULL; 493 } 494 495 static int nilfs_sync_fs(struct super_block *sb, int wait) 496 { 497 struct the_nilfs *nilfs = sb->s_fs_info; 498 struct nilfs_super_block **sbp; 499 int err = 0; 500 501 /* This function is called when super block should be written back */ 502 if (wait) 503 err = nilfs_construct_segment(sb); 504 505 down_write(&nilfs->ns_sem); 506 if (nilfs_sb_dirty(nilfs)) { 507 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs)); 508 if (likely(sbp)) { 509 nilfs_set_log_cursor(sbp[0], nilfs); 510 nilfs_commit_super(sb, NILFS_SB_COMMIT); 511 } 512 } 513 up_write(&nilfs->ns_sem); 514 515 if (!err) 516 err = nilfs_flush_device(nilfs); 517 518 return err; 519 } 520 521 int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt, 522 struct nilfs_root **rootp) 523 { 524 struct the_nilfs *nilfs = sb->s_fs_info; 525 struct nilfs_root *root; 526 struct nilfs_checkpoint *raw_cp; 527 struct buffer_head *bh_cp; 528 int err = -ENOMEM; 529 530 root = nilfs_find_or_create_root( 531 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno); 532 if (!root) 533 return err; 534 535 if (root->ifile) 536 goto reuse; /* already attached checkpoint */ 537 538 down_read(&nilfs->ns_segctor_sem); 539 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, 540 &bh_cp); 541 up_read(&nilfs->ns_segctor_sem); 542 if (unlikely(err)) { 543 if (err == -ENOENT || err == -EINVAL) { 544 nilfs_msg(sb, KERN_ERR, 545 "Invalid checkpoint (checkpoint number=%llu)", 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 atomic64_set(&root->inodes_count, 558 le64_to_cpu(raw_cp->cp_inodes_count)); 559 atomic64_set(&root->blocks_count, 560 le64_to_cpu(raw_cp->cp_blocks_count)); 561 562 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); 563 564 reuse: 565 *rootp = root; 566 return 0; 567 568 failed_bh: 569 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); 570 failed: 571 nilfs_put_root(root); 572 573 return err; 574 } 575 576 static int nilfs_freeze(struct super_block *sb) 577 { 578 struct the_nilfs *nilfs = sb->s_fs_info; 579 int err; 580 581 if (sb_rdonly(sb)) 582 return 0; 583 584 /* Mark super block clean */ 585 down_write(&nilfs->ns_sem); 586 err = nilfs_cleanup_super(sb); 587 up_write(&nilfs->ns_sem); 588 return err; 589 } 590 591 static int nilfs_unfreeze(struct super_block *sb) 592 { 593 struct the_nilfs *nilfs = sb->s_fs_info; 594 595 if (sb_rdonly(sb)) 596 return 0; 597 598 down_write(&nilfs->ns_sem); 599 nilfs_setup_super(sb, false); 600 up_write(&nilfs->ns_sem); 601 return 0; 602 } 603 604 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) 605 { 606 struct super_block *sb = dentry->d_sb; 607 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root; 608 struct the_nilfs *nilfs = root->nilfs; 609 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 610 unsigned long long blocks; 611 unsigned long overhead; 612 unsigned long nrsvblocks; 613 sector_t nfreeblocks; 614 u64 nmaxinodes, nfreeinodes; 615 int err; 616 617 /* 618 * Compute all of the segment blocks 619 * 620 * The blocks before first segment and after last segment 621 * are excluded. 622 */ 623 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments 624 - nilfs->ns_first_data_block; 625 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; 626 627 /* 628 * Compute the overhead 629 * 630 * When distributing meta data blocks outside segment structure, 631 * We must count them as the overhead. 632 */ 633 overhead = 0; 634 635 err = nilfs_count_free_blocks(nilfs, &nfreeblocks); 636 if (unlikely(err)) 637 return err; 638 639 err = nilfs_ifile_count_free_inodes(root->ifile, 640 &nmaxinodes, &nfreeinodes); 641 if (unlikely(err)) { 642 nilfs_msg(sb, KERN_WARNING, 643 "failed to count free inodes: err=%d", err); 644 if (err == -ERANGE) { 645 /* 646 * If nilfs_palloc_count_max_entries() returns 647 * -ERANGE error code then we simply treat 648 * curent inodes count as maximum possible and 649 * zero as free inodes value. 650 */ 651 nmaxinodes = atomic64_read(&root->inodes_count); 652 nfreeinodes = 0; 653 err = 0; 654 } else 655 return err; 656 } 657 658 buf->f_type = NILFS_SUPER_MAGIC; 659 buf->f_bsize = sb->s_blocksize; 660 buf->f_blocks = blocks - overhead; 661 buf->f_bfree = nfreeblocks; 662 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? 663 (buf->f_bfree - nrsvblocks) : 0; 664 buf->f_files = nmaxinodes; 665 buf->f_ffree = nfreeinodes; 666 buf->f_namelen = NILFS_NAME_LEN; 667 buf->f_fsid.val[0] = (u32)id; 668 buf->f_fsid.val[1] = (u32)(id >> 32); 669 670 return 0; 671 } 672 673 static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry) 674 { 675 struct super_block *sb = dentry->d_sb; 676 struct the_nilfs *nilfs = sb->s_fs_info; 677 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root; 678 679 if (!nilfs_test_opt(nilfs, BARRIER)) 680 seq_puts(seq, ",nobarrier"); 681 if (root->cno != NILFS_CPTREE_CURRENT_CNO) 682 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno); 683 if (nilfs_test_opt(nilfs, ERRORS_PANIC)) 684 seq_puts(seq, ",errors=panic"); 685 if (nilfs_test_opt(nilfs, ERRORS_CONT)) 686 seq_puts(seq, ",errors=continue"); 687 if (nilfs_test_opt(nilfs, STRICT_ORDER)) 688 seq_puts(seq, ",order=strict"); 689 if (nilfs_test_opt(nilfs, NORECOVERY)) 690 seq_puts(seq, ",norecovery"); 691 if (nilfs_test_opt(nilfs, DISCARD)) 692 seq_puts(seq, ",discard"); 693 694 return 0; 695 } 696 697 static const struct super_operations nilfs_sops = { 698 .alloc_inode = nilfs_alloc_inode, 699 .destroy_inode = nilfs_destroy_inode, 700 .dirty_inode = nilfs_dirty_inode, 701 .evict_inode = nilfs_evict_inode, 702 .put_super = nilfs_put_super, 703 .sync_fs = nilfs_sync_fs, 704 .freeze_fs = nilfs_freeze, 705 .unfreeze_fs = nilfs_unfreeze, 706 .statfs = nilfs_statfs, 707 .remount_fs = nilfs_remount, 708 .show_options = nilfs_show_options 709 }; 710 711 enum { 712 Opt_err_cont, Opt_err_panic, Opt_err_ro, 713 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery, 714 Opt_discard, Opt_nodiscard, Opt_err, 715 }; 716 717 static match_table_t tokens = { 718 {Opt_err_cont, "errors=continue"}, 719 {Opt_err_panic, "errors=panic"}, 720 {Opt_err_ro, "errors=remount-ro"}, 721 {Opt_barrier, "barrier"}, 722 {Opt_nobarrier, "nobarrier"}, 723 {Opt_snapshot, "cp=%u"}, 724 {Opt_order, "order=%s"}, 725 {Opt_norecovery, "norecovery"}, 726 {Opt_discard, "discard"}, 727 {Opt_nodiscard, "nodiscard"}, 728 {Opt_err, NULL} 729 }; 730 731 static int parse_options(char *options, struct super_block *sb, int is_remount) 732 { 733 struct the_nilfs *nilfs = sb->s_fs_info; 734 char *p; 735 substring_t args[MAX_OPT_ARGS]; 736 737 if (!options) 738 return 1; 739 740 while ((p = strsep(&options, ",")) != NULL) { 741 int token; 742 743 if (!*p) 744 continue; 745 746 token = match_token(p, tokens, args); 747 switch (token) { 748 case Opt_barrier: 749 nilfs_set_opt(nilfs, BARRIER); 750 break; 751 case Opt_nobarrier: 752 nilfs_clear_opt(nilfs, BARRIER); 753 break; 754 case Opt_order: 755 if (strcmp(args[0].from, "relaxed") == 0) 756 /* Ordered data semantics */ 757 nilfs_clear_opt(nilfs, STRICT_ORDER); 758 else if (strcmp(args[0].from, "strict") == 0) 759 /* Strict in-order semantics */ 760 nilfs_set_opt(nilfs, STRICT_ORDER); 761 else 762 return 0; 763 break; 764 case Opt_err_panic: 765 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC); 766 break; 767 case Opt_err_ro: 768 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO); 769 break; 770 case Opt_err_cont: 771 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT); 772 break; 773 case Opt_snapshot: 774 if (is_remount) { 775 nilfs_msg(sb, KERN_ERR, 776 "\"%s\" option is invalid for remount", 777 p); 778 return 0; 779 } 780 break; 781 case Opt_norecovery: 782 nilfs_set_opt(nilfs, NORECOVERY); 783 break; 784 case Opt_discard: 785 nilfs_set_opt(nilfs, DISCARD); 786 break; 787 case Opt_nodiscard: 788 nilfs_clear_opt(nilfs, DISCARD); 789 break; 790 default: 791 nilfs_msg(sb, KERN_ERR, 792 "unrecognized mount option \"%s\"", p); 793 return 0; 794 } 795 } 796 return 1; 797 } 798 799 static inline void 800 nilfs_set_default_options(struct super_block *sb, 801 struct nilfs_super_block *sbp) 802 { 803 struct the_nilfs *nilfs = sb->s_fs_info; 804 805 nilfs->ns_mount_opt = 806 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER; 807 } 808 809 static int nilfs_setup_super(struct super_block *sb, int is_mount) 810 { 811 struct the_nilfs *nilfs = sb->s_fs_info; 812 struct nilfs_super_block **sbp; 813 int max_mnt_count; 814 int mnt_count; 815 816 /* nilfs->ns_sem must be locked by the caller. */ 817 sbp = nilfs_prepare_super(sb, 0); 818 if (!sbp) 819 return -EIO; 820 821 if (!is_mount) 822 goto skip_mount_setup; 823 824 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count); 825 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count); 826 827 if (nilfs->ns_mount_state & NILFS_ERROR_FS) { 828 nilfs_msg(sb, KERN_WARNING, "mounting fs with errors"); 829 #if 0 830 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { 831 nilfs_msg(sb, KERN_WARNING, "maximal mount count reached"); 832 #endif 833 } 834 if (!max_mnt_count) 835 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); 836 837 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1); 838 sbp[0]->s_mtime = cpu_to_le64(get_seconds()); 839 840 skip_mount_setup: 841 sbp[0]->s_state = 842 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS); 843 /* synchronize sbp[1] with sbp[0] */ 844 if (sbp[1]) 845 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); 846 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); 847 } 848 849 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb, 850 u64 pos, int blocksize, 851 struct buffer_head **pbh) 852 { 853 unsigned long long sb_index = pos; 854 unsigned long offset; 855 856 offset = do_div(sb_index, blocksize); 857 *pbh = sb_bread(sb, sb_index); 858 if (!*pbh) 859 return NULL; 860 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); 861 } 862 863 int nilfs_store_magic_and_option(struct super_block *sb, 864 struct nilfs_super_block *sbp, 865 char *data) 866 { 867 struct the_nilfs *nilfs = sb->s_fs_info; 868 869 sb->s_magic = le16_to_cpu(sbp->s_magic); 870 871 /* FS independent flags */ 872 #ifdef NILFS_ATIME_DISABLE 873 sb->s_flags |= MS_NOATIME; 874 #endif 875 876 nilfs_set_default_options(sb, sbp); 877 878 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid); 879 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid); 880 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval); 881 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max); 882 883 return !parse_options(data, sb, 0) ? -EINVAL : 0; 884 } 885 886 int nilfs_check_feature_compatibility(struct super_block *sb, 887 struct nilfs_super_block *sbp) 888 { 889 __u64 features; 890 891 features = le64_to_cpu(sbp->s_feature_incompat) & 892 ~NILFS_FEATURE_INCOMPAT_SUPP; 893 if (features) { 894 nilfs_msg(sb, KERN_ERR, 895 "couldn't mount because of unsupported optional features (%llx)", 896 (unsigned long long)features); 897 return -EINVAL; 898 } 899 features = le64_to_cpu(sbp->s_feature_compat_ro) & 900 ~NILFS_FEATURE_COMPAT_RO_SUPP; 901 if (!sb_rdonly(sb) && features) { 902 nilfs_msg(sb, KERN_ERR, 903 "couldn't mount RDWR because of unsupported optional features (%llx)", 904 (unsigned long long)features); 905 return -EINVAL; 906 } 907 return 0; 908 } 909 910 static int nilfs_get_root_dentry(struct super_block *sb, 911 struct nilfs_root *root, 912 struct dentry **root_dentry) 913 { 914 struct inode *inode; 915 struct dentry *dentry; 916 int ret = 0; 917 918 inode = nilfs_iget(sb, root, NILFS_ROOT_INO); 919 if (IS_ERR(inode)) { 920 ret = PTR_ERR(inode); 921 nilfs_msg(sb, KERN_ERR, "error %d getting root inode", ret); 922 goto out; 923 } 924 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) { 925 iput(inode); 926 nilfs_msg(sb, KERN_ERR, "corrupt root inode"); 927 ret = -EINVAL; 928 goto out; 929 } 930 931 if (root->cno == NILFS_CPTREE_CURRENT_CNO) { 932 dentry = d_find_alias(inode); 933 if (!dentry) { 934 dentry = d_make_root(inode); 935 if (!dentry) { 936 ret = -ENOMEM; 937 goto failed_dentry; 938 } 939 } else { 940 iput(inode); 941 } 942 } else { 943 dentry = d_obtain_root(inode); 944 if (IS_ERR(dentry)) { 945 ret = PTR_ERR(dentry); 946 goto failed_dentry; 947 } 948 } 949 *root_dentry = dentry; 950 out: 951 return ret; 952 953 failed_dentry: 954 nilfs_msg(sb, KERN_ERR, "error %d getting root dentry", ret); 955 goto out; 956 } 957 958 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno, 959 struct dentry **root_dentry) 960 { 961 struct the_nilfs *nilfs = s->s_fs_info; 962 struct nilfs_root *root; 963 int ret; 964 965 mutex_lock(&nilfs->ns_snapshot_mount_mutex); 966 967 down_read(&nilfs->ns_segctor_sem); 968 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno); 969 up_read(&nilfs->ns_segctor_sem); 970 if (ret < 0) { 971 ret = (ret == -ENOENT) ? -EINVAL : ret; 972 goto out; 973 } else if (!ret) { 974 nilfs_msg(s, KERN_ERR, 975 "The specified checkpoint is not a snapshot (checkpoint number=%llu)", 976 (unsigned long long)cno); 977 ret = -EINVAL; 978 goto out; 979 } 980 981 ret = nilfs_attach_checkpoint(s, cno, false, &root); 982 if (ret) { 983 nilfs_msg(s, KERN_ERR, 984 "error %d while loading snapshot (checkpoint number=%llu)", 985 ret, (unsigned long long)cno); 986 goto out; 987 } 988 ret = nilfs_get_root_dentry(s, root, root_dentry); 989 nilfs_put_root(root); 990 out: 991 mutex_unlock(&nilfs->ns_snapshot_mount_mutex); 992 return ret; 993 } 994 995 /** 996 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint 997 * @root_dentry: root dentry of the tree to be shrunk 998 * 999 * This function returns true if the tree was in-use. 1000 */ 1001 static bool nilfs_tree_is_busy(struct dentry *root_dentry) 1002 { 1003 shrink_dcache_parent(root_dentry); 1004 return d_count(root_dentry) > 1; 1005 } 1006 1007 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno) 1008 { 1009 struct the_nilfs *nilfs = sb->s_fs_info; 1010 struct nilfs_root *root; 1011 struct inode *inode; 1012 struct dentry *dentry; 1013 int ret; 1014 1015 if (cno > nilfs->ns_cno) 1016 return false; 1017 1018 if (cno >= nilfs_last_cno(nilfs)) 1019 return true; /* protect recent checkpoints */ 1020 1021 ret = false; 1022 root = nilfs_lookup_root(nilfs, cno); 1023 if (root) { 1024 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO); 1025 if (inode) { 1026 dentry = d_find_alias(inode); 1027 if (dentry) { 1028 ret = nilfs_tree_is_busy(dentry); 1029 dput(dentry); 1030 } 1031 iput(inode); 1032 } 1033 nilfs_put_root(root); 1034 } 1035 return ret; 1036 } 1037 1038 /** 1039 * nilfs_fill_super() - initialize a super block instance 1040 * @sb: super_block 1041 * @data: mount options 1042 * @silent: silent mode flag 1043 * 1044 * This function is called exclusively by nilfs->ns_mount_mutex. 1045 * So, the recovery process is protected from other simultaneous mounts. 1046 */ 1047 static int 1048 nilfs_fill_super(struct super_block *sb, void *data, int silent) 1049 { 1050 struct the_nilfs *nilfs; 1051 struct nilfs_root *fsroot; 1052 __u64 cno; 1053 int err; 1054 1055 nilfs = alloc_nilfs(sb); 1056 if (!nilfs) 1057 return -ENOMEM; 1058 1059 sb->s_fs_info = nilfs; 1060 1061 err = init_nilfs(nilfs, sb, (char *)data); 1062 if (err) 1063 goto failed_nilfs; 1064 1065 sb->s_op = &nilfs_sops; 1066 sb->s_export_op = &nilfs_export_ops; 1067 sb->s_root = NULL; 1068 sb->s_time_gran = 1; 1069 sb->s_max_links = NILFS_LINK_MAX; 1070 1071 sb->s_bdi = bdi_get(sb->s_bdev->bd_bdi); 1072 1073 err = load_nilfs(nilfs, sb); 1074 if (err) 1075 goto failed_nilfs; 1076 1077 cno = nilfs_last_cno(nilfs); 1078 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot); 1079 if (err) { 1080 nilfs_msg(sb, KERN_ERR, 1081 "error %d while loading last checkpoint (checkpoint number=%llu)", 1082 err, (unsigned long long)cno); 1083 goto failed_unload; 1084 } 1085 1086 if (!sb_rdonly(sb)) { 1087 err = nilfs_attach_log_writer(sb, fsroot); 1088 if (err) 1089 goto failed_checkpoint; 1090 } 1091 1092 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root); 1093 if (err) 1094 goto failed_segctor; 1095 1096 nilfs_put_root(fsroot); 1097 1098 if (!sb_rdonly(sb)) { 1099 down_write(&nilfs->ns_sem); 1100 nilfs_setup_super(sb, true); 1101 up_write(&nilfs->ns_sem); 1102 } 1103 1104 return 0; 1105 1106 failed_segctor: 1107 nilfs_detach_log_writer(sb); 1108 1109 failed_checkpoint: 1110 nilfs_put_root(fsroot); 1111 1112 failed_unload: 1113 iput(nilfs->ns_sufile); 1114 iput(nilfs->ns_cpfile); 1115 iput(nilfs->ns_dat); 1116 1117 failed_nilfs: 1118 destroy_nilfs(nilfs); 1119 return err; 1120 } 1121 1122 static int nilfs_remount(struct super_block *sb, int *flags, char *data) 1123 { 1124 struct the_nilfs *nilfs = sb->s_fs_info; 1125 unsigned long old_sb_flags; 1126 unsigned long old_mount_opt; 1127 int err; 1128 1129 sync_filesystem(sb); 1130 old_sb_flags = sb->s_flags; 1131 old_mount_opt = nilfs->ns_mount_opt; 1132 1133 if (!parse_options(data, sb, 1)) { 1134 err = -EINVAL; 1135 goto restore_opts; 1136 } 1137 sb->s_flags = (sb->s_flags & ~MS_POSIXACL); 1138 1139 err = -EINVAL; 1140 1141 if (!nilfs_valid_fs(nilfs)) { 1142 nilfs_msg(sb, KERN_WARNING, 1143 "couldn't remount because the filesystem is in an incomplete recovery state"); 1144 goto restore_opts; 1145 } 1146 1147 if ((bool)(*flags & MS_RDONLY) == sb_rdonly(sb)) 1148 goto out; 1149 if (*flags & MS_RDONLY) { 1150 /* Shutting down log writer */ 1151 nilfs_detach_log_writer(sb); 1152 sb->s_flags |= MS_RDONLY; 1153 1154 /* 1155 * Remounting a valid RW partition RDONLY, so set 1156 * the RDONLY flag and then mark the partition as valid again. 1157 */ 1158 down_write(&nilfs->ns_sem); 1159 nilfs_cleanup_super(sb); 1160 up_write(&nilfs->ns_sem); 1161 } else { 1162 __u64 features; 1163 struct nilfs_root *root; 1164 1165 /* 1166 * Mounting a RDONLY partition read-write, so reread and 1167 * store the current valid flag. (It may have been changed 1168 * by fsck since we originally mounted the partition.) 1169 */ 1170 down_read(&nilfs->ns_sem); 1171 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 1172 ~NILFS_FEATURE_COMPAT_RO_SUPP; 1173 up_read(&nilfs->ns_sem); 1174 if (features) { 1175 nilfs_msg(sb, KERN_WARNING, 1176 "couldn't remount RDWR because of unsupported optional features (%llx)", 1177 (unsigned long long)features); 1178 err = -EROFS; 1179 goto restore_opts; 1180 } 1181 1182 sb->s_flags &= ~MS_RDONLY; 1183 1184 root = NILFS_I(d_inode(sb->s_root))->i_root; 1185 err = nilfs_attach_log_writer(sb, root); 1186 if (err) 1187 goto restore_opts; 1188 1189 down_write(&nilfs->ns_sem); 1190 nilfs_setup_super(sb, true); 1191 up_write(&nilfs->ns_sem); 1192 } 1193 out: 1194 return 0; 1195 1196 restore_opts: 1197 sb->s_flags = old_sb_flags; 1198 nilfs->ns_mount_opt = old_mount_opt; 1199 return err; 1200 } 1201 1202 struct nilfs_super_data { 1203 struct block_device *bdev; 1204 __u64 cno; 1205 int flags; 1206 }; 1207 1208 static int nilfs_parse_snapshot_option(const char *option, 1209 const substring_t *arg, 1210 struct nilfs_super_data *sd) 1211 { 1212 unsigned long long val; 1213 const char *msg = NULL; 1214 int err; 1215 1216 if (!(sd->flags & MS_RDONLY)) { 1217 msg = "read-only option is not specified"; 1218 goto parse_error; 1219 } 1220 1221 err = kstrtoull(arg->from, 0, &val); 1222 if (err) { 1223 if (err == -ERANGE) 1224 msg = "too large checkpoint number"; 1225 else 1226 msg = "malformed argument"; 1227 goto parse_error; 1228 } else if (val == 0) { 1229 msg = "invalid checkpoint number 0"; 1230 goto parse_error; 1231 } 1232 sd->cno = val; 1233 return 0; 1234 1235 parse_error: 1236 nilfs_msg(NULL, KERN_ERR, "invalid option \"%s\": %s", option, msg); 1237 return 1; 1238 } 1239 1240 /** 1241 * nilfs_identify - pre-read mount options needed to identify mount instance 1242 * @data: mount options 1243 * @sd: nilfs_super_data 1244 */ 1245 static int nilfs_identify(char *data, struct nilfs_super_data *sd) 1246 { 1247 char *p, *options = data; 1248 substring_t args[MAX_OPT_ARGS]; 1249 int token; 1250 int ret = 0; 1251 1252 do { 1253 p = strsep(&options, ","); 1254 if (p != NULL && *p) { 1255 token = match_token(p, tokens, args); 1256 if (token == Opt_snapshot) 1257 ret = nilfs_parse_snapshot_option(p, &args[0], 1258 sd); 1259 } 1260 if (!options) 1261 break; 1262 BUG_ON(options == data); 1263 *(options - 1) = ','; 1264 } while (!ret); 1265 return ret; 1266 } 1267 1268 static int nilfs_set_bdev_super(struct super_block *s, void *data) 1269 { 1270 s->s_bdev = data; 1271 s->s_dev = s->s_bdev->bd_dev; 1272 return 0; 1273 } 1274 1275 static int nilfs_test_bdev_super(struct super_block *s, void *data) 1276 { 1277 return (void *)s->s_bdev == data; 1278 } 1279 1280 static struct dentry * 1281 nilfs_mount(struct file_system_type *fs_type, int flags, 1282 const char *dev_name, void *data) 1283 { 1284 struct nilfs_super_data sd; 1285 struct super_block *s; 1286 fmode_t mode = FMODE_READ | FMODE_EXCL; 1287 struct dentry *root_dentry; 1288 int err, s_new = false; 1289 1290 if (!(flags & MS_RDONLY)) 1291 mode |= FMODE_WRITE; 1292 1293 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type); 1294 if (IS_ERR(sd.bdev)) 1295 return ERR_CAST(sd.bdev); 1296 1297 sd.cno = 0; 1298 sd.flags = flags; 1299 if (nilfs_identify((char *)data, &sd)) { 1300 err = -EINVAL; 1301 goto failed; 1302 } 1303 1304 /* 1305 * once the super is inserted into the list by sget, s_umount 1306 * will protect the lockfs code from trying to start a snapshot 1307 * while we are mounting 1308 */ 1309 mutex_lock(&sd.bdev->bd_fsfreeze_mutex); 1310 if (sd.bdev->bd_fsfreeze_count > 0) { 1311 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); 1312 err = -EBUSY; 1313 goto failed; 1314 } 1315 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags, 1316 sd.bdev); 1317 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); 1318 if (IS_ERR(s)) { 1319 err = PTR_ERR(s); 1320 goto failed; 1321 } 1322 1323 if (!s->s_root) { 1324 s_new = true; 1325 1326 /* New superblock instance created */ 1327 s->s_mode = mode; 1328 snprintf(s->s_id, sizeof(s->s_id), "%pg", sd.bdev); 1329 sb_set_blocksize(s, block_size(sd.bdev)); 1330 1331 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0); 1332 if (err) 1333 goto failed_super; 1334 1335 s->s_flags |= MS_ACTIVE; 1336 } else if (!sd.cno) { 1337 if (nilfs_tree_is_busy(s->s_root)) { 1338 if ((flags ^ s->s_flags) & MS_RDONLY) { 1339 nilfs_msg(s, KERN_ERR, 1340 "the device already has a %s mount.", 1341 sb_rdonly(s) ? "read-only" : "read/write"); 1342 err = -EBUSY; 1343 goto failed_super; 1344 } 1345 } else { 1346 /* 1347 * Try remount to setup mount states if the current 1348 * tree is not mounted and only snapshots use this sb. 1349 */ 1350 err = nilfs_remount(s, &flags, data); 1351 if (err) 1352 goto failed_super; 1353 } 1354 } 1355 1356 if (sd.cno) { 1357 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry); 1358 if (err) 1359 goto failed_super; 1360 } else { 1361 root_dentry = dget(s->s_root); 1362 } 1363 1364 if (!s_new) 1365 blkdev_put(sd.bdev, mode); 1366 1367 return root_dentry; 1368 1369 failed_super: 1370 deactivate_locked_super(s); 1371 1372 failed: 1373 if (!s_new) 1374 blkdev_put(sd.bdev, mode); 1375 return ERR_PTR(err); 1376 } 1377 1378 struct file_system_type nilfs_fs_type = { 1379 .owner = THIS_MODULE, 1380 .name = "nilfs2", 1381 .mount = nilfs_mount, 1382 .kill_sb = kill_block_super, 1383 .fs_flags = FS_REQUIRES_DEV, 1384 }; 1385 MODULE_ALIAS_FS("nilfs2"); 1386 1387 static void nilfs_inode_init_once(void *obj) 1388 { 1389 struct nilfs_inode_info *ii = obj; 1390 1391 INIT_LIST_HEAD(&ii->i_dirty); 1392 #ifdef CONFIG_NILFS_XATTR 1393 init_rwsem(&ii->xattr_sem); 1394 #endif 1395 address_space_init_once(&ii->i_btnode_cache); 1396 ii->i_bmap = &ii->i_bmap_data; 1397 inode_init_once(&ii->vfs_inode); 1398 } 1399 1400 static void nilfs_segbuf_init_once(void *obj) 1401 { 1402 memset(obj, 0, sizeof(struct nilfs_segment_buffer)); 1403 } 1404 1405 static void nilfs_destroy_cachep(void) 1406 { 1407 /* 1408 * Make sure all delayed rcu free inodes are flushed before we 1409 * destroy cache. 1410 */ 1411 rcu_barrier(); 1412 1413 kmem_cache_destroy(nilfs_inode_cachep); 1414 kmem_cache_destroy(nilfs_transaction_cachep); 1415 kmem_cache_destroy(nilfs_segbuf_cachep); 1416 kmem_cache_destroy(nilfs_btree_path_cache); 1417 } 1418 1419 static int __init nilfs_init_cachep(void) 1420 { 1421 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", 1422 sizeof(struct nilfs_inode_info), 0, 1423 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT, 1424 nilfs_inode_init_once); 1425 if (!nilfs_inode_cachep) 1426 goto fail; 1427 1428 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache", 1429 sizeof(struct nilfs_transaction_info), 0, 1430 SLAB_RECLAIM_ACCOUNT, NULL); 1431 if (!nilfs_transaction_cachep) 1432 goto fail; 1433 1434 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache", 1435 sizeof(struct nilfs_segment_buffer), 0, 1436 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once); 1437 if (!nilfs_segbuf_cachep) 1438 goto fail; 1439 1440 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache", 1441 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX, 1442 0, 0, NULL); 1443 if (!nilfs_btree_path_cache) 1444 goto fail; 1445 1446 return 0; 1447 1448 fail: 1449 nilfs_destroy_cachep(); 1450 return -ENOMEM; 1451 } 1452 1453 static int __init init_nilfs_fs(void) 1454 { 1455 int err; 1456 1457 err = nilfs_init_cachep(); 1458 if (err) 1459 goto fail; 1460 1461 err = nilfs_sysfs_init(); 1462 if (err) 1463 goto free_cachep; 1464 1465 err = register_filesystem(&nilfs_fs_type); 1466 if (err) 1467 goto deinit_sysfs_entry; 1468 1469 printk(KERN_INFO "NILFS version 2 loaded\n"); 1470 return 0; 1471 1472 deinit_sysfs_entry: 1473 nilfs_sysfs_exit(); 1474 free_cachep: 1475 nilfs_destroy_cachep(); 1476 fail: 1477 return err; 1478 } 1479 1480 static void __exit exit_nilfs_fs(void) 1481 { 1482 nilfs_destroy_cachep(); 1483 nilfs_sysfs_exit(); 1484 unregister_filesystem(&nilfs_fs_type); 1485 } 1486 1487 module_init(init_nilfs_fs) 1488 module_exit(exit_nilfs_fs) 1489