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); 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 nilfs->ns_flushed_device = 1; 314 /* make sure store to ns_flushed_device cannot be reordered */ 315 smp_wmb(); 316 return nilfs_sync_super(sb, flag); 317 } 318 319 /** 320 * nilfs_cleanup_super() - write filesystem state for cleanup 321 * @sb: super block instance to be unmounted or degraded to read-only 322 * 323 * This function restores state flags in the on-disk super block. 324 * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the 325 * filesystem was not clean previously. 326 */ 327 int nilfs_cleanup_super(struct super_block *sb) 328 { 329 struct the_nilfs *nilfs = sb->s_fs_info; 330 struct nilfs_super_block **sbp; 331 int flag = NILFS_SB_COMMIT; 332 int ret = -EIO; 333 334 sbp = nilfs_prepare_super(sb, 0); 335 if (sbp) { 336 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state); 337 nilfs_set_log_cursor(sbp[0], nilfs); 338 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) { 339 /* 340 * make the "clean" flag also to the opposite 341 * super block if both super blocks point to 342 * the same checkpoint. 343 */ 344 sbp[1]->s_state = sbp[0]->s_state; 345 flag = NILFS_SB_COMMIT_ALL; 346 } 347 ret = nilfs_commit_super(sb, flag); 348 } 349 return ret; 350 } 351 352 /** 353 * nilfs_move_2nd_super - relocate secondary super block 354 * @sb: super block instance 355 * @sb2off: new offset of the secondary super block (in bytes) 356 */ 357 static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off) 358 { 359 struct the_nilfs *nilfs = sb->s_fs_info; 360 struct buffer_head *nsbh; 361 struct nilfs_super_block *nsbp; 362 sector_t blocknr, newblocknr; 363 unsigned long offset; 364 int sb2i = -1; /* array index of the secondary superblock */ 365 int ret = 0; 366 367 /* nilfs->ns_sem must be locked by the caller. */ 368 if (nilfs->ns_sbh[1] && 369 nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) { 370 sb2i = 1; 371 blocknr = nilfs->ns_sbh[1]->b_blocknr; 372 } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) { 373 sb2i = 0; 374 blocknr = nilfs->ns_sbh[0]->b_blocknr; 375 } 376 if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off) 377 goto out; /* super block location is unchanged */ 378 379 /* Get new super block buffer */ 380 newblocknr = sb2off >> nilfs->ns_blocksize_bits; 381 offset = sb2off & (nilfs->ns_blocksize - 1); 382 nsbh = sb_getblk(sb, newblocknr); 383 if (!nsbh) { 384 printk(KERN_WARNING 385 "NILFS warning: unable to move secondary superblock " 386 "to block %llu\n", (unsigned long long)newblocknr); 387 ret = -EIO; 388 goto out; 389 } 390 nsbp = (void *)nsbh->b_data + offset; 391 memset(nsbp, 0, nilfs->ns_blocksize); 392 393 if (sb2i >= 0) { 394 memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize); 395 brelse(nilfs->ns_sbh[sb2i]); 396 nilfs->ns_sbh[sb2i] = nsbh; 397 nilfs->ns_sbp[sb2i] = nsbp; 398 } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) { 399 /* secondary super block will be restored to index 1 */ 400 nilfs->ns_sbh[1] = nsbh; 401 nilfs->ns_sbp[1] = nsbp; 402 } else { 403 brelse(nsbh); 404 } 405 out: 406 return ret; 407 } 408 409 /** 410 * nilfs_resize_fs - resize the filesystem 411 * @sb: super block instance 412 * @newsize: new size of the filesystem (in bytes) 413 */ 414 int nilfs_resize_fs(struct super_block *sb, __u64 newsize) 415 { 416 struct the_nilfs *nilfs = sb->s_fs_info; 417 struct nilfs_super_block **sbp; 418 __u64 devsize, newnsegs; 419 loff_t sb2off; 420 int ret; 421 422 ret = -ERANGE; 423 devsize = i_size_read(sb->s_bdev->bd_inode); 424 if (newsize > devsize) 425 goto out; 426 427 /* 428 * Write lock is required to protect some functions depending 429 * on the number of segments, the number of reserved segments, 430 * and so forth. 431 */ 432 down_write(&nilfs->ns_segctor_sem); 433 434 sb2off = NILFS_SB2_OFFSET_BYTES(newsize); 435 newnsegs = sb2off >> nilfs->ns_blocksize_bits; 436 do_div(newnsegs, nilfs->ns_blocks_per_segment); 437 438 ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs); 439 up_write(&nilfs->ns_segctor_sem); 440 if (ret < 0) 441 goto out; 442 443 ret = nilfs_construct_segment(sb); 444 if (ret < 0) 445 goto out; 446 447 down_write(&nilfs->ns_sem); 448 nilfs_move_2nd_super(sb, sb2off); 449 ret = -EIO; 450 sbp = nilfs_prepare_super(sb, 0); 451 if (likely(sbp)) { 452 nilfs_set_log_cursor(sbp[0], nilfs); 453 /* 454 * Drop NILFS_RESIZE_FS flag for compatibility with 455 * mount-time resize which may be implemented in a 456 * future release. 457 */ 458 sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & 459 ~NILFS_RESIZE_FS); 460 sbp[0]->s_dev_size = cpu_to_le64(newsize); 461 sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments); 462 if (sbp[1]) 463 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); 464 ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); 465 } 466 up_write(&nilfs->ns_sem); 467 468 /* 469 * Reset the range of allocatable segments last. This order 470 * is important in the case of expansion because the secondary 471 * superblock must be protected from log write until migration 472 * completes. 473 */ 474 if (!ret) 475 nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1); 476 out: 477 return ret; 478 } 479 480 static void nilfs_put_super(struct super_block *sb) 481 { 482 struct the_nilfs *nilfs = sb->s_fs_info; 483 484 nilfs_detach_log_writer(sb); 485 486 if (!(sb->s_flags & MS_RDONLY)) { 487 down_write(&nilfs->ns_sem); 488 nilfs_cleanup_super(sb); 489 up_write(&nilfs->ns_sem); 490 } 491 492 iput(nilfs->ns_sufile); 493 iput(nilfs->ns_cpfile); 494 iput(nilfs->ns_dat); 495 496 destroy_nilfs(nilfs); 497 sb->s_fs_info = NULL; 498 } 499 500 static int nilfs_sync_fs(struct super_block *sb, int wait) 501 { 502 struct the_nilfs *nilfs = sb->s_fs_info; 503 struct nilfs_super_block **sbp; 504 int err = 0; 505 506 /* This function is called when super block should be written back */ 507 if (wait) 508 err = nilfs_construct_segment(sb); 509 510 down_write(&nilfs->ns_sem); 511 if (nilfs_sb_dirty(nilfs)) { 512 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs)); 513 if (likely(sbp)) { 514 nilfs_set_log_cursor(sbp[0], nilfs); 515 nilfs_commit_super(sb, NILFS_SB_COMMIT); 516 } 517 } 518 up_write(&nilfs->ns_sem); 519 520 if (!err) 521 err = nilfs_flush_device(nilfs); 522 523 return err; 524 } 525 526 int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt, 527 struct nilfs_root **rootp) 528 { 529 struct the_nilfs *nilfs = sb->s_fs_info; 530 struct nilfs_root *root; 531 struct nilfs_checkpoint *raw_cp; 532 struct buffer_head *bh_cp; 533 int err = -ENOMEM; 534 535 root = nilfs_find_or_create_root( 536 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno); 537 if (!root) 538 return err; 539 540 if (root->ifile) 541 goto reuse; /* already attached checkpoint */ 542 543 down_read(&nilfs->ns_segctor_sem); 544 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, 545 &bh_cp); 546 up_read(&nilfs->ns_segctor_sem); 547 if (unlikely(err)) { 548 if (err == -ENOENT || err == -EINVAL) { 549 printk(KERN_ERR 550 "NILFS: Invalid checkpoint " 551 "(checkpoint number=%llu)\n", 552 (unsigned long long)cno); 553 err = -EINVAL; 554 } 555 goto failed; 556 } 557 558 err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size, 559 &raw_cp->cp_ifile_inode, &root->ifile); 560 if (err) 561 goto failed_bh; 562 563 atomic64_set(&root->inodes_count, 564 le64_to_cpu(raw_cp->cp_inodes_count)); 565 atomic64_set(&root->blocks_count, 566 le64_to_cpu(raw_cp->cp_blocks_count)); 567 568 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); 569 570 reuse: 571 *rootp = root; 572 return 0; 573 574 failed_bh: 575 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp); 576 failed: 577 nilfs_put_root(root); 578 579 return err; 580 } 581 582 static int nilfs_freeze(struct super_block *sb) 583 { 584 struct the_nilfs *nilfs = sb->s_fs_info; 585 int err; 586 587 if (sb->s_flags & MS_RDONLY) 588 return 0; 589 590 /* Mark super block clean */ 591 down_write(&nilfs->ns_sem); 592 err = nilfs_cleanup_super(sb); 593 up_write(&nilfs->ns_sem); 594 return err; 595 } 596 597 static int nilfs_unfreeze(struct super_block *sb) 598 { 599 struct the_nilfs *nilfs = sb->s_fs_info; 600 601 if (sb->s_flags & MS_RDONLY) 602 return 0; 603 604 down_write(&nilfs->ns_sem); 605 nilfs_setup_super(sb, false); 606 up_write(&nilfs->ns_sem); 607 return 0; 608 } 609 610 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) 611 { 612 struct super_block *sb = dentry->d_sb; 613 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root; 614 struct the_nilfs *nilfs = root->nilfs; 615 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 616 unsigned long long blocks; 617 unsigned long overhead; 618 unsigned long nrsvblocks; 619 sector_t nfreeblocks; 620 u64 nmaxinodes, nfreeinodes; 621 int err; 622 623 /* 624 * Compute all of the segment blocks 625 * 626 * The blocks before first segment and after last segment 627 * are excluded. 628 */ 629 blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments 630 - nilfs->ns_first_data_block; 631 nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment; 632 633 /* 634 * Compute the overhead 635 * 636 * When distributing meta data blocks outside segment structure, 637 * We must count them as the overhead. 638 */ 639 overhead = 0; 640 641 err = nilfs_count_free_blocks(nilfs, &nfreeblocks); 642 if (unlikely(err)) 643 return err; 644 645 err = nilfs_ifile_count_free_inodes(root->ifile, 646 &nmaxinodes, &nfreeinodes); 647 if (unlikely(err)) { 648 printk(KERN_WARNING 649 "NILFS warning: fail to count free inodes: err %d.\n", 650 err); 651 if (err == -ERANGE) { 652 /* 653 * If nilfs_palloc_count_max_entries() returns 654 * -ERANGE error code then we simply treat 655 * curent inodes count as maximum possible and 656 * zero as free inodes value. 657 */ 658 nmaxinodes = atomic64_read(&root->inodes_count); 659 nfreeinodes = 0; 660 err = 0; 661 } else 662 return err; 663 } 664 665 buf->f_type = NILFS_SUPER_MAGIC; 666 buf->f_bsize = sb->s_blocksize; 667 buf->f_blocks = blocks - overhead; 668 buf->f_bfree = nfreeblocks; 669 buf->f_bavail = (buf->f_bfree >= nrsvblocks) ? 670 (buf->f_bfree - nrsvblocks) : 0; 671 buf->f_files = nmaxinodes; 672 buf->f_ffree = nfreeinodes; 673 buf->f_namelen = NILFS_NAME_LEN; 674 buf->f_fsid.val[0] = (u32)id; 675 buf->f_fsid.val[1] = (u32)(id >> 32); 676 677 return 0; 678 } 679 680 static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry) 681 { 682 struct super_block *sb = dentry->d_sb; 683 struct the_nilfs *nilfs = sb->s_fs_info; 684 struct nilfs_root *root = NILFS_I(d_inode(dentry))->i_root; 685 686 if (!nilfs_test_opt(nilfs, BARRIER)) 687 seq_puts(seq, ",nobarrier"); 688 if (root->cno != NILFS_CPTREE_CURRENT_CNO) 689 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno); 690 if (nilfs_test_opt(nilfs, ERRORS_PANIC)) 691 seq_puts(seq, ",errors=panic"); 692 if (nilfs_test_opt(nilfs, ERRORS_CONT)) 693 seq_puts(seq, ",errors=continue"); 694 if (nilfs_test_opt(nilfs, STRICT_ORDER)) 695 seq_puts(seq, ",order=strict"); 696 if (nilfs_test_opt(nilfs, NORECOVERY)) 697 seq_puts(seq, ",norecovery"); 698 if (nilfs_test_opt(nilfs, DISCARD)) 699 seq_puts(seq, ",discard"); 700 701 return 0; 702 } 703 704 static const struct super_operations nilfs_sops = { 705 .alloc_inode = nilfs_alloc_inode, 706 .destroy_inode = nilfs_destroy_inode, 707 .dirty_inode = nilfs_dirty_inode, 708 .evict_inode = nilfs_evict_inode, 709 .put_super = nilfs_put_super, 710 .sync_fs = nilfs_sync_fs, 711 .freeze_fs = nilfs_freeze, 712 .unfreeze_fs = nilfs_unfreeze, 713 .statfs = nilfs_statfs, 714 .remount_fs = nilfs_remount, 715 .show_options = nilfs_show_options 716 }; 717 718 enum { 719 Opt_err_cont, Opt_err_panic, Opt_err_ro, 720 Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery, 721 Opt_discard, Opt_nodiscard, Opt_err, 722 }; 723 724 static match_table_t tokens = { 725 {Opt_err_cont, "errors=continue"}, 726 {Opt_err_panic, "errors=panic"}, 727 {Opt_err_ro, "errors=remount-ro"}, 728 {Opt_barrier, "barrier"}, 729 {Opt_nobarrier, "nobarrier"}, 730 {Opt_snapshot, "cp=%u"}, 731 {Opt_order, "order=%s"}, 732 {Opt_norecovery, "norecovery"}, 733 {Opt_discard, "discard"}, 734 {Opt_nodiscard, "nodiscard"}, 735 {Opt_err, NULL} 736 }; 737 738 static int parse_options(char *options, struct super_block *sb, int is_remount) 739 { 740 struct the_nilfs *nilfs = sb->s_fs_info; 741 char *p; 742 substring_t args[MAX_OPT_ARGS]; 743 744 if (!options) 745 return 1; 746 747 while ((p = strsep(&options, ",")) != NULL) { 748 int token; 749 if (!*p) 750 continue; 751 752 token = match_token(p, tokens, args); 753 switch (token) { 754 case Opt_barrier: 755 nilfs_set_opt(nilfs, BARRIER); 756 break; 757 case Opt_nobarrier: 758 nilfs_clear_opt(nilfs, BARRIER); 759 break; 760 case Opt_order: 761 if (strcmp(args[0].from, "relaxed") == 0) 762 /* Ordered data semantics */ 763 nilfs_clear_opt(nilfs, STRICT_ORDER); 764 else if (strcmp(args[0].from, "strict") == 0) 765 /* Strict in-order semantics */ 766 nilfs_set_opt(nilfs, STRICT_ORDER); 767 else 768 return 0; 769 break; 770 case Opt_err_panic: 771 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC); 772 break; 773 case Opt_err_ro: 774 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO); 775 break; 776 case Opt_err_cont: 777 nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT); 778 break; 779 case Opt_snapshot: 780 if (is_remount) { 781 printk(KERN_ERR 782 "NILFS: \"%s\" option is invalid " 783 "for remount.\n", p); 784 return 0; 785 } 786 break; 787 case Opt_norecovery: 788 nilfs_set_opt(nilfs, NORECOVERY); 789 break; 790 case Opt_discard: 791 nilfs_set_opt(nilfs, DISCARD); 792 break; 793 case Opt_nodiscard: 794 nilfs_clear_opt(nilfs, DISCARD); 795 break; 796 default: 797 printk(KERN_ERR 798 "NILFS: Unrecognized mount option \"%s\"\n", p); 799 return 0; 800 } 801 } 802 return 1; 803 } 804 805 static inline void 806 nilfs_set_default_options(struct super_block *sb, 807 struct nilfs_super_block *sbp) 808 { 809 struct the_nilfs *nilfs = sb->s_fs_info; 810 811 nilfs->ns_mount_opt = 812 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER; 813 } 814 815 static int nilfs_setup_super(struct super_block *sb, int is_mount) 816 { 817 struct the_nilfs *nilfs = sb->s_fs_info; 818 struct nilfs_super_block **sbp; 819 int max_mnt_count; 820 int mnt_count; 821 822 /* nilfs->ns_sem must be locked by the caller. */ 823 sbp = nilfs_prepare_super(sb, 0); 824 if (!sbp) 825 return -EIO; 826 827 if (!is_mount) 828 goto skip_mount_setup; 829 830 max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count); 831 mnt_count = le16_to_cpu(sbp[0]->s_mnt_count); 832 833 if (nilfs->ns_mount_state & NILFS_ERROR_FS) { 834 printk(KERN_WARNING 835 "NILFS warning: mounting fs with errors\n"); 836 #if 0 837 } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) { 838 printk(KERN_WARNING 839 "NILFS warning: maximal mount count reached\n"); 840 #endif 841 } 842 if (!max_mnt_count) 843 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT); 844 845 sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1); 846 sbp[0]->s_mtime = cpu_to_le64(get_seconds()); 847 848 skip_mount_setup: 849 sbp[0]->s_state = 850 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS); 851 /* synchronize sbp[1] with sbp[0] */ 852 if (sbp[1]) 853 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize); 854 return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL); 855 } 856 857 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb, 858 u64 pos, int blocksize, 859 struct buffer_head **pbh) 860 { 861 unsigned long long sb_index = pos; 862 unsigned long offset; 863 864 offset = do_div(sb_index, blocksize); 865 *pbh = sb_bread(sb, sb_index); 866 if (!*pbh) 867 return NULL; 868 return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset); 869 } 870 871 int nilfs_store_magic_and_option(struct super_block *sb, 872 struct nilfs_super_block *sbp, 873 char *data) 874 { 875 struct the_nilfs *nilfs = sb->s_fs_info; 876 877 sb->s_magic = le16_to_cpu(sbp->s_magic); 878 879 /* FS independent flags */ 880 #ifdef NILFS_ATIME_DISABLE 881 sb->s_flags |= MS_NOATIME; 882 #endif 883 884 nilfs_set_default_options(sb, sbp); 885 886 nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid); 887 nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid); 888 nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval); 889 nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max); 890 891 return !parse_options(data, sb, 0) ? -EINVAL : 0 ; 892 } 893 894 int nilfs_check_feature_compatibility(struct super_block *sb, 895 struct nilfs_super_block *sbp) 896 { 897 __u64 features; 898 899 features = le64_to_cpu(sbp->s_feature_incompat) & 900 ~NILFS_FEATURE_INCOMPAT_SUPP; 901 if (features) { 902 printk(KERN_ERR "NILFS: couldn't mount because of unsupported " 903 "optional features (%llx)\n", 904 (unsigned long long)features); 905 return -EINVAL; 906 } 907 features = le64_to_cpu(sbp->s_feature_compat_ro) & 908 ~NILFS_FEATURE_COMPAT_RO_SUPP; 909 if (!(sb->s_flags & MS_RDONLY) && features) { 910 printk(KERN_ERR "NILFS: couldn't mount RDWR because of " 911 "unsupported optional features (%llx)\n", 912 (unsigned long long)features); 913 return -EINVAL; 914 } 915 return 0; 916 } 917 918 static int nilfs_get_root_dentry(struct super_block *sb, 919 struct nilfs_root *root, 920 struct dentry **root_dentry) 921 { 922 struct inode *inode; 923 struct dentry *dentry; 924 int ret = 0; 925 926 inode = nilfs_iget(sb, root, NILFS_ROOT_INO); 927 if (IS_ERR(inode)) { 928 printk(KERN_ERR "NILFS: get root inode failed\n"); 929 ret = PTR_ERR(inode); 930 goto out; 931 } 932 if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) { 933 iput(inode); 934 printk(KERN_ERR "NILFS: corrupt root inode.\n"); 935 ret = -EINVAL; 936 goto out; 937 } 938 939 if (root->cno == NILFS_CPTREE_CURRENT_CNO) { 940 dentry = d_find_alias(inode); 941 if (!dentry) { 942 dentry = d_make_root(inode); 943 if (!dentry) { 944 ret = -ENOMEM; 945 goto failed_dentry; 946 } 947 } else { 948 iput(inode); 949 } 950 } else { 951 dentry = d_obtain_root(inode); 952 if (IS_ERR(dentry)) { 953 ret = PTR_ERR(dentry); 954 goto failed_dentry; 955 } 956 } 957 *root_dentry = dentry; 958 out: 959 return ret; 960 961 failed_dentry: 962 printk(KERN_ERR "NILFS: get root dentry failed\n"); 963 goto out; 964 } 965 966 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno, 967 struct dentry **root_dentry) 968 { 969 struct the_nilfs *nilfs = s->s_fs_info; 970 struct nilfs_root *root; 971 int ret; 972 973 mutex_lock(&nilfs->ns_snapshot_mount_mutex); 974 975 down_read(&nilfs->ns_segctor_sem); 976 ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno); 977 up_read(&nilfs->ns_segctor_sem); 978 if (ret < 0) { 979 ret = (ret == -ENOENT) ? -EINVAL : ret; 980 goto out; 981 } else if (!ret) { 982 printk(KERN_ERR "NILFS: The specified checkpoint is " 983 "not a snapshot (checkpoint number=%llu).\n", 984 (unsigned long long)cno); 985 ret = -EINVAL; 986 goto out; 987 } 988 989 ret = nilfs_attach_checkpoint(s, cno, false, &root); 990 if (ret) { 991 printk(KERN_ERR "NILFS: error loading snapshot " 992 "(checkpoint number=%llu).\n", 993 (unsigned long long)cno); 994 goto out; 995 } 996 ret = nilfs_get_root_dentry(s, root, root_dentry); 997 nilfs_put_root(root); 998 out: 999 mutex_unlock(&nilfs->ns_snapshot_mount_mutex); 1000 return ret; 1001 } 1002 1003 /** 1004 * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint 1005 * @root_dentry: root dentry of the tree to be shrunk 1006 * 1007 * This function returns true if the tree was in-use. 1008 */ 1009 static bool nilfs_tree_is_busy(struct dentry *root_dentry) 1010 { 1011 shrink_dcache_parent(root_dentry); 1012 return d_count(root_dentry) > 1; 1013 } 1014 1015 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno) 1016 { 1017 struct the_nilfs *nilfs = sb->s_fs_info; 1018 struct nilfs_root *root; 1019 struct inode *inode; 1020 struct dentry *dentry; 1021 int ret; 1022 1023 if (cno > nilfs->ns_cno) 1024 return false; 1025 1026 if (cno >= nilfs_last_cno(nilfs)) 1027 return true; /* protect recent checkpoints */ 1028 1029 ret = false; 1030 root = nilfs_lookup_root(nilfs, cno); 1031 if (root) { 1032 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO); 1033 if (inode) { 1034 dentry = d_find_alias(inode); 1035 if (dentry) { 1036 ret = nilfs_tree_is_busy(dentry); 1037 dput(dentry); 1038 } 1039 iput(inode); 1040 } 1041 nilfs_put_root(root); 1042 } 1043 return ret; 1044 } 1045 1046 /** 1047 * nilfs_fill_super() - initialize a super block instance 1048 * @sb: super_block 1049 * @data: mount options 1050 * @silent: silent mode flag 1051 * 1052 * This function is called exclusively by nilfs->ns_mount_mutex. 1053 * So, the recovery process is protected from other simultaneous mounts. 1054 */ 1055 static int 1056 nilfs_fill_super(struct super_block *sb, void *data, int silent) 1057 { 1058 struct the_nilfs *nilfs; 1059 struct nilfs_root *fsroot; 1060 __u64 cno; 1061 int err; 1062 1063 nilfs = alloc_nilfs(sb->s_bdev); 1064 if (!nilfs) 1065 return -ENOMEM; 1066 1067 sb->s_fs_info = nilfs; 1068 1069 err = init_nilfs(nilfs, sb, (char *)data); 1070 if (err) 1071 goto failed_nilfs; 1072 1073 sb->s_op = &nilfs_sops; 1074 sb->s_export_op = &nilfs_export_ops; 1075 sb->s_root = NULL; 1076 sb->s_time_gran = 1; 1077 sb->s_max_links = NILFS_LINK_MAX; 1078 1079 sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info; 1080 1081 err = load_nilfs(nilfs, sb); 1082 if (err) 1083 goto failed_nilfs; 1084 1085 cno = nilfs_last_cno(nilfs); 1086 err = nilfs_attach_checkpoint(sb, cno, true, &fsroot); 1087 if (err) { 1088 printk(KERN_ERR "NILFS: error loading last checkpoint " 1089 "(checkpoint number=%llu).\n", (unsigned long long)cno); 1090 goto failed_unload; 1091 } 1092 1093 if (!(sb->s_flags & MS_RDONLY)) { 1094 err = nilfs_attach_log_writer(sb, fsroot); 1095 if (err) 1096 goto failed_checkpoint; 1097 } 1098 1099 err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root); 1100 if (err) 1101 goto failed_segctor; 1102 1103 nilfs_put_root(fsroot); 1104 1105 if (!(sb->s_flags & MS_RDONLY)) { 1106 down_write(&nilfs->ns_sem); 1107 nilfs_setup_super(sb, true); 1108 up_write(&nilfs->ns_sem); 1109 } 1110 1111 return 0; 1112 1113 failed_segctor: 1114 nilfs_detach_log_writer(sb); 1115 1116 failed_checkpoint: 1117 nilfs_put_root(fsroot); 1118 1119 failed_unload: 1120 iput(nilfs->ns_sufile); 1121 iput(nilfs->ns_cpfile); 1122 iput(nilfs->ns_dat); 1123 1124 failed_nilfs: 1125 destroy_nilfs(nilfs); 1126 return err; 1127 } 1128 1129 static int nilfs_remount(struct super_block *sb, int *flags, char *data) 1130 { 1131 struct the_nilfs *nilfs = sb->s_fs_info; 1132 unsigned long old_sb_flags; 1133 unsigned long old_mount_opt; 1134 int err; 1135 1136 sync_filesystem(sb); 1137 old_sb_flags = sb->s_flags; 1138 old_mount_opt = nilfs->ns_mount_opt; 1139 1140 if (!parse_options(data, sb, 1)) { 1141 err = -EINVAL; 1142 goto restore_opts; 1143 } 1144 sb->s_flags = (sb->s_flags & ~MS_POSIXACL); 1145 1146 err = -EINVAL; 1147 1148 if (!nilfs_valid_fs(nilfs)) { 1149 printk(KERN_WARNING "NILFS (device %s): couldn't " 1150 "remount because the filesystem is in an " 1151 "incomplete recovery state.\n", sb->s_id); 1152 goto restore_opts; 1153 } 1154 1155 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1156 goto out; 1157 if (*flags & MS_RDONLY) { 1158 /* Shutting down log writer */ 1159 nilfs_detach_log_writer(sb); 1160 sb->s_flags |= MS_RDONLY; 1161 1162 /* 1163 * Remounting a valid RW partition RDONLY, so set 1164 * the RDONLY flag and then mark the partition as valid again. 1165 */ 1166 down_write(&nilfs->ns_sem); 1167 nilfs_cleanup_super(sb); 1168 up_write(&nilfs->ns_sem); 1169 } else { 1170 __u64 features; 1171 struct nilfs_root *root; 1172 1173 /* 1174 * Mounting a RDONLY partition read-write, so reread and 1175 * store the current valid flag. (It may have been changed 1176 * by fsck since we originally mounted the partition.) 1177 */ 1178 down_read(&nilfs->ns_sem); 1179 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 1180 ~NILFS_FEATURE_COMPAT_RO_SUPP; 1181 up_read(&nilfs->ns_sem); 1182 if (features) { 1183 printk(KERN_WARNING "NILFS (device %s): couldn't " 1184 "remount RDWR because of unsupported optional " 1185 "features (%llx)\n", 1186 sb->s_id, (unsigned long long)features); 1187 err = -EROFS; 1188 goto restore_opts; 1189 } 1190 1191 sb->s_flags &= ~MS_RDONLY; 1192 1193 root = NILFS_I(d_inode(sb->s_root))->i_root; 1194 err = nilfs_attach_log_writer(sb, root); 1195 if (err) 1196 goto restore_opts; 1197 1198 down_write(&nilfs->ns_sem); 1199 nilfs_setup_super(sb, true); 1200 up_write(&nilfs->ns_sem); 1201 } 1202 out: 1203 return 0; 1204 1205 restore_opts: 1206 sb->s_flags = old_sb_flags; 1207 nilfs->ns_mount_opt = old_mount_opt; 1208 return err; 1209 } 1210 1211 struct nilfs_super_data { 1212 struct block_device *bdev; 1213 __u64 cno; 1214 int flags; 1215 }; 1216 1217 /** 1218 * nilfs_identify - pre-read mount options needed to identify mount instance 1219 * @data: mount options 1220 * @sd: nilfs_super_data 1221 */ 1222 static int nilfs_identify(char *data, struct nilfs_super_data *sd) 1223 { 1224 char *p, *options = data; 1225 substring_t args[MAX_OPT_ARGS]; 1226 int token; 1227 int ret = 0; 1228 1229 do { 1230 p = strsep(&options, ","); 1231 if (p != NULL && *p) { 1232 token = match_token(p, tokens, args); 1233 if (token == Opt_snapshot) { 1234 if (!(sd->flags & MS_RDONLY)) { 1235 ret++; 1236 } else { 1237 sd->cno = simple_strtoull(args[0].from, 1238 NULL, 0); 1239 /* 1240 * No need to see the end pointer; 1241 * match_token() has done syntax 1242 * checking. 1243 */ 1244 if (sd->cno == 0) 1245 ret++; 1246 } 1247 } 1248 if (ret) 1249 printk(KERN_ERR 1250 "NILFS: invalid mount option: %s\n", p); 1251 } 1252 if (!options) 1253 break; 1254 BUG_ON(options == data); 1255 *(options - 1) = ','; 1256 } while (!ret); 1257 return ret; 1258 } 1259 1260 static int nilfs_set_bdev_super(struct super_block *s, void *data) 1261 { 1262 s->s_bdev = data; 1263 s->s_dev = s->s_bdev->bd_dev; 1264 return 0; 1265 } 1266 1267 static int nilfs_test_bdev_super(struct super_block *s, void *data) 1268 { 1269 return (void *)s->s_bdev == data; 1270 } 1271 1272 static struct dentry * 1273 nilfs_mount(struct file_system_type *fs_type, int flags, 1274 const char *dev_name, void *data) 1275 { 1276 struct nilfs_super_data sd; 1277 struct super_block *s; 1278 fmode_t mode = FMODE_READ | FMODE_EXCL; 1279 struct dentry *root_dentry; 1280 int err, s_new = false; 1281 1282 if (!(flags & MS_RDONLY)) 1283 mode |= FMODE_WRITE; 1284 1285 sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type); 1286 if (IS_ERR(sd.bdev)) 1287 return ERR_CAST(sd.bdev); 1288 1289 sd.cno = 0; 1290 sd.flags = flags; 1291 if (nilfs_identify((char *)data, &sd)) { 1292 err = -EINVAL; 1293 goto failed; 1294 } 1295 1296 /* 1297 * once the super is inserted into the list by sget, s_umount 1298 * will protect the lockfs code from trying to start a snapshot 1299 * while we are mounting 1300 */ 1301 mutex_lock(&sd.bdev->bd_fsfreeze_mutex); 1302 if (sd.bdev->bd_fsfreeze_count > 0) { 1303 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); 1304 err = -EBUSY; 1305 goto failed; 1306 } 1307 s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags, 1308 sd.bdev); 1309 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex); 1310 if (IS_ERR(s)) { 1311 err = PTR_ERR(s); 1312 goto failed; 1313 } 1314 1315 if (!s->s_root) { 1316 char b[BDEVNAME_SIZE]; 1317 1318 s_new = true; 1319 1320 /* New superblock instance created */ 1321 s->s_mode = mode; 1322 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id)); 1323 sb_set_blocksize(s, block_size(sd.bdev)); 1324 1325 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0); 1326 if (err) 1327 goto failed_super; 1328 1329 s->s_flags |= MS_ACTIVE; 1330 } else if (!sd.cno) { 1331 if (nilfs_tree_is_busy(s->s_root)) { 1332 if ((flags ^ s->s_flags) & MS_RDONLY) { 1333 printk(KERN_ERR "NILFS: the device already " 1334 "has a %s mount.\n", 1335 (s->s_flags & MS_RDONLY) ? 1336 "read-only" : "read/write"); 1337 err = -EBUSY; 1338 goto failed_super; 1339 } 1340 } else { 1341 /* 1342 * Try remount to setup mount states if the current 1343 * tree is not mounted and only snapshots use this sb. 1344 */ 1345 err = nilfs_remount(s, &flags, data); 1346 if (err) 1347 goto failed_super; 1348 } 1349 } 1350 1351 if (sd.cno) { 1352 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry); 1353 if (err) 1354 goto failed_super; 1355 } else { 1356 root_dentry = dget(s->s_root); 1357 } 1358 1359 if (!s_new) 1360 blkdev_put(sd.bdev, mode); 1361 1362 return root_dentry; 1363 1364 failed_super: 1365 deactivate_locked_super(s); 1366 1367 failed: 1368 if (!s_new) 1369 blkdev_put(sd.bdev, mode); 1370 return ERR_PTR(err); 1371 } 1372 1373 struct file_system_type nilfs_fs_type = { 1374 .owner = THIS_MODULE, 1375 .name = "nilfs2", 1376 .mount = nilfs_mount, 1377 .kill_sb = kill_block_super, 1378 .fs_flags = FS_REQUIRES_DEV, 1379 }; 1380 MODULE_ALIAS_FS("nilfs2"); 1381 1382 static void nilfs_inode_init_once(void *obj) 1383 { 1384 struct nilfs_inode_info *ii = obj; 1385 1386 INIT_LIST_HEAD(&ii->i_dirty); 1387 #ifdef CONFIG_NILFS_XATTR 1388 init_rwsem(&ii->xattr_sem); 1389 #endif 1390 address_space_init_once(&ii->i_btnode_cache); 1391 ii->i_bmap = &ii->i_bmap_data; 1392 inode_init_once(&ii->vfs_inode); 1393 } 1394 1395 static void nilfs_segbuf_init_once(void *obj) 1396 { 1397 memset(obj, 0, sizeof(struct nilfs_segment_buffer)); 1398 } 1399 1400 static void nilfs_destroy_cachep(void) 1401 { 1402 /* 1403 * Make sure all delayed rcu free inodes are flushed before we 1404 * destroy cache. 1405 */ 1406 rcu_barrier(); 1407 1408 if (nilfs_inode_cachep) 1409 kmem_cache_destroy(nilfs_inode_cachep); 1410 if (nilfs_transaction_cachep) 1411 kmem_cache_destroy(nilfs_transaction_cachep); 1412 if (nilfs_segbuf_cachep) 1413 kmem_cache_destroy(nilfs_segbuf_cachep); 1414 if (nilfs_btree_path_cache) 1415 kmem_cache_destroy(nilfs_btree_path_cache); 1416 } 1417 1418 static int __init nilfs_init_cachep(void) 1419 { 1420 nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache", 1421 sizeof(struct nilfs_inode_info), 0, 1422 SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once); 1423 if (!nilfs_inode_cachep) 1424 goto fail; 1425 1426 nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache", 1427 sizeof(struct nilfs_transaction_info), 0, 1428 SLAB_RECLAIM_ACCOUNT, NULL); 1429 if (!nilfs_transaction_cachep) 1430 goto fail; 1431 1432 nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache", 1433 sizeof(struct nilfs_segment_buffer), 0, 1434 SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once); 1435 if (!nilfs_segbuf_cachep) 1436 goto fail; 1437 1438 nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache", 1439 sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX, 1440 0, 0, NULL); 1441 if (!nilfs_btree_path_cache) 1442 goto fail; 1443 1444 return 0; 1445 1446 fail: 1447 nilfs_destroy_cachep(); 1448 return -ENOMEM; 1449 } 1450 1451 static int __init init_nilfs_fs(void) 1452 { 1453 int err; 1454 1455 err = nilfs_init_cachep(); 1456 if (err) 1457 goto fail; 1458 1459 err = nilfs_sysfs_init(); 1460 if (err) 1461 goto free_cachep; 1462 1463 err = register_filesystem(&nilfs_fs_type); 1464 if (err) 1465 goto deinit_sysfs_entry; 1466 1467 printk(KERN_INFO "NILFS version 2 loaded\n"); 1468 return 0; 1469 1470 deinit_sysfs_entry: 1471 nilfs_sysfs_exit(); 1472 free_cachep: 1473 nilfs_destroy_cachep(); 1474 fail: 1475 return err; 1476 } 1477 1478 static void __exit exit_nilfs_fs(void) 1479 { 1480 nilfs_destroy_cachep(); 1481 nilfs_sysfs_exit(); 1482 unregister_filesystem(&nilfs_fs_type); 1483 } 1484 1485 module_init(init_nilfs_fs) 1486 module_exit(exit_nilfs_fs) 1487