1 /* 2 * the_nilfs.c - the_nilfs shared structure. 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 24 #include <linux/buffer_head.h> 25 #include <linux/slab.h> 26 #include <linux/blkdev.h> 27 #include <linux/backing-dev.h> 28 #include <linux/random.h> 29 #include <linux/crc32.h> 30 #include "nilfs.h" 31 #include "segment.h" 32 #include "alloc.h" 33 #include "cpfile.h" 34 #include "sufile.h" 35 #include "dat.h" 36 #include "segbuf.h" 37 38 39 static int nilfs_valid_sb(struct nilfs_super_block *sbp); 40 41 void nilfs_set_last_segment(struct the_nilfs *nilfs, 42 sector_t start_blocknr, u64 seq, __u64 cno) 43 { 44 spin_lock(&nilfs->ns_last_segment_lock); 45 nilfs->ns_last_pseg = start_blocknr; 46 nilfs->ns_last_seq = seq; 47 nilfs->ns_last_cno = cno; 48 49 if (!nilfs_sb_dirty(nilfs)) { 50 if (nilfs->ns_prev_seq == nilfs->ns_last_seq) 51 goto stay_cursor; 52 53 set_nilfs_sb_dirty(nilfs); 54 } 55 nilfs->ns_prev_seq = nilfs->ns_last_seq; 56 57 stay_cursor: 58 spin_unlock(&nilfs->ns_last_segment_lock); 59 } 60 61 /** 62 * alloc_nilfs - allocate a nilfs object 63 * @bdev: block device to which the_nilfs is related 64 * 65 * Return Value: On success, pointer to the_nilfs is returned. 66 * On error, NULL is returned. 67 */ 68 struct the_nilfs *alloc_nilfs(struct block_device *bdev) 69 { 70 struct the_nilfs *nilfs; 71 72 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL); 73 if (!nilfs) 74 return NULL; 75 76 nilfs->ns_bdev = bdev; 77 atomic_set(&nilfs->ns_ndirtyblks, 0); 78 init_rwsem(&nilfs->ns_sem); 79 INIT_LIST_HEAD(&nilfs->ns_dirty_files); 80 INIT_LIST_HEAD(&nilfs->ns_gc_inodes); 81 spin_lock_init(&nilfs->ns_inode_lock); 82 spin_lock_init(&nilfs->ns_next_gen_lock); 83 spin_lock_init(&nilfs->ns_last_segment_lock); 84 nilfs->ns_cptree = RB_ROOT; 85 spin_lock_init(&nilfs->ns_cptree_lock); 86 init_rwsem(&nilfs->ns_segctor_sem); 87 88 return nilfs; 89 } 90 91 /** 92 * destroy_nilfs - destroy nilfs object 93 * @nilfs: nilfs object to be released 94 */ 95 void destroy_nilfs(struct the_nilfs *nilfs) 96 { 97 might_sleep(); 98 if (nilfs_init(nilfs)) { 99 brelse(nilfs->ns_sbh[0]); 100 brelse(nilfs->ns_sbh[1]); 101 } 102 kfree(nilfs); 103 } 104 105 static int nilfs_load_super_root(struct the_nilfs *nilfs, 106 struct super_block *sb, sector_t sr_block) 107 { 108 struct buffer_head *bh_sr; 109 struct nilfs_super_root *raw_sr; 110 struct nilfs_super_block **sbp = nilfs->ns_sbp; 111 struct nilfs_inode *rawi; 112 unsigned dat_entry_size, segment_usage_size, checkpoint_size; 113 unsigned inode_size; 114 int err; 115 116 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1); 117 if (unlikely(err)) 118 return err; 119 120 down_read(&nilfs->ns_sem); 121 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size); 122 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size); 123 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size); 124 up_read(&nilfs->ns_sem); 125 126 inode_size = nilfs->ns_inode_size; 127 128 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size); 129 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat); 130 if (err) 131 goto failed; 132 133 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size); 134 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile); 135 if (err) 136 goto failed_dat; 137 138 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size); 139 err = nilfs_sufile_read(sb, segment_usage_size, rawi, 140 &nilfs->ns_sufile); 141 if (err) 142 goto failed_cpfile; 143 144 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 145 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime); 146 147 failed: 148 brelse(bh_sr); 149 return err; 150 151 failed_cpfile: 152 iput(nilfs->ns_cpfile); 153 154 failed_dat: 155 iput(nilfs->ns_dat); 156 goto failed; 157 } 158 159 static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri) 160 { 161 memset(ri, 0, sizeof(*ri)); 162 INIT_LIST_HEAD(&ri->ri_used_segments); 163 } 164 165 static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri) 166 { 167 nilfs_dispose_segment_list(&ri->ri_used_segments); 168 } 169 170 /** 171 * nilfs_store_log_cursor - load log cursor from a super block 172 * @nilfs: nilfs object 173 * @sbp: buffer storing super block to be read 174 * 175 * nilfs_store_log_cursor() reads the last position of the log 176 * containing a super root from a given super block, and initializes 177 * relevant information on the nilfs object preparatory for log 178 * scanning and recovery. 179 */ 180 static int nilfs_store_log_cursor(struct the_nilfs *nilfs, 181 struct nilfs_super_block *sbp) 182 { 183 int ret = 0; 184 185 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg); 186 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno); 187 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq); 188 189 nilfs->ns_prev_seq = nilfs->ns_last_seq; 190 nilfs->ns_seg_seq = nilfs->ns_last_seq; 191 nilfs->ns_segnum = 192 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg); 193 nilfs->ns_cno = nilfs->ns_last_cno + 1; 194 if (nilfs->ns_segnum >= nilfs->ns_nsegments) { 195 printk(KERN_ERR "NILFS invalid last segment number.\n"); 196 ret = -EINVAL; 197 } 198 return ret; 199 } 200 201 /** 202 * load_nilfs - load and recover the nilfs 203 * @nilfs: the_nilfs structure to be released 204 * @sb: super block isntance used to recover past segment 205 * 206 * load_nilfs() searches and load the latest super root, 207 * attaches the last segment, and does recovery if needed. 208 * The caller must call this exclusively for simultaneous mounts. 209 */ 210 int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb) 211 { 212 struct nilfs_recovery_info ri; 213 unsigned int s_flags = sb->s_flags; 214 int really_read_only = bdev_read_only(nilfs->ns_bdev); 215 int valid_fs = nilfs_valid_fs(nilfs); 216 int err; 217 218 if (!valid_fs) { 219 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); 220 if (s_flags & MS_RDONLY) { 221 printk(KERN_INFO "NILFS: INFO: recovery " 222 "required for readonly filesystem.\n"); 223 printk(KERN_INFO "NILFS: write access will " 224 "be enabled during recovery.\n"); 225 } 226 } 227 228 nilfs_init_recovery_info(&ri); 229 230 err = nilfs_search_super_root(nilfs, &ri); 231 if (unlikely(err)) { 232 struct nilfs_super_block **sbp = nilfs->ns_sbp; 233 int blocksize; 234 235 if (err != -EINVAL) 236 goto scan_error; 237 238 if (!nilfs_valid_sb(sbp[1])) { 239 printk(KERN_WARNING 240 "NILFS warning: unable to fall back to spare" 241 "super block\n"); 242 goto scan_error; 243 } 244 printk(KERN_INFO 245 "NILFS: try rollback from an earlier position\n"); 246 247 /* 248 * restore super block with its spare and reconfigure 249 * relevant states of the nilfs object. 250 */ 251 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 252 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed); 253 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 254 255 /* verify consistency between two super blocks */ 256 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size); 257 if (blocksize != nilfs->ns_blocksize) { 258 printk(KERN_WARNING 259 "NILFS warning: blocksize differs between " 260 "two super blocks (%d != %d)\n", 261 blocksize, nilfs->ns_blocksize); 262 goto scan_error; 263 } 264 265 err = nilfs_store_log_cursor(nilfs, sbp[0]); 266 if (err) 267 goto scan_error; 268 269 /* drop clean flag to allow roll-forward and recovery */ 270 nilfs->ns_mount_state &= ~NILFS_VALID_FS; 271 valid_fs = 0; 272 273 err = nilfs_search_super_root(nilfs, &ri); 274 if (err) 275 goto scan_error; 276 } 277 278 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root); 279 if (unlikely(err)) { 280 printk(KERN_ERR "NILFS: error loading super root.\n"); 281 goto failed; 282 } 283 284 if (valid_fs) 285 goto skip_recovery; 286 287 if (s_flags & MS_RDONLY) { 288 __u64 features; 289 290 if (nilfs_test_opt(nilfs, NORECOVERY)) { 291 printk(KERN_INFO "NILFS: norecovery option specified. " 292 "skipping roll-forward recovery\n"); 293 goto skip_recovery; 294 } 295 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 296 ~NILFS_FEATURE_COMPAT_RO_SUPP; 297 if (features) { 298 printk(KERN_ERR "NILFS: couldn't proceed with " 299 "recovery because of unsupported optional " 300 "features (%llx)\n", 301 (unsigned long long)features); 302 err = -EROFS; 303 goto failed_unload; 304 } 305 if (really_read_only) { 306 printk(KERN_ERR "NILFS: write access " 307 "unavailable, cannot proceed.\n"); 308 err = -EROFS; 309 goto failed_unload; 310 } 311 sb->s_flags &= ~MS_RDONLY; 312 } else if (nilfs_test_opt(nilfs, NORECOVERY)) { 313 printk(KERN_ERR "NILFS: recovery cancelled because norecovery " 314 "option was specified for a read/write mount\n"); 315 err = -EINVAL; 316 goto failed_unload; 317 } 318 319 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri); 320 if (err) 321 goto failed_unload; 322 323 down_write(&nilfs->ns_sem); 324 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */ 325 err = nilfs_cleanup_super(sb); 326 up_write(&nilfs->ns_sem); 327 328 if (err) { 329 printk(KERN_ERR "NILFS: failed to update super block. " 330 "recovery unfinished.\n"); 331 goto failed_unload; 332 } 333 printk(KERN_INFO "NILFS: recovery complete.\n"); 334 335 skip_recovery: 336 nilfs_clear_recovery_info(&ri); 337 sb->s_flags = s_flags; 338 return 0; 339 340 scan_error: 341 printk(KERN_ERR "NILFS: error searching super root.\n"); 342 goto failed; 343 344 failed_unload: 345 iput(nilfs->ns_cpfile); 346 iput(nilfs->ns_sufile); 347 iput(nilfs->ns_dat); 348 349 failed: 350 nilfs_clear_recovery_info(&ri); 351 sb->s_flags = s_flags; 352 return err; 353 } 354 355 static unsigned long long nilfs_max_size(unsigned int blkbits) 356 { 357 unsigned int max_bits; 358 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ 359 360 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ 361 if (max_bits < 64) 362 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); 363 return res; 364 } 365 366 /** 367 * nilfs_nrsvsegs - calculate the number of reserved segments 368 * @nilfs: nilfs object 369 * @nsegs: total number of segments 370 */ 371 unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs) 372 { 373 return max_t(unsigned long, NILFS_MIN_NRSVSEGS, 374 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage, 375 100)); 376 } 377 378 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs) 379 { 380 nilfs->ns_nsegments = nsegs; 381 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs); 382 } 383 384 static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 385 struct nilfs_super_block *sbp) 386 { 387 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 388 printk(KERN_ERR "NILFS: unsupported revision " 389 "(superblock rev.=%d.%d, current rev.=%d.%d). " 390 "Please check the version of mkfs.nilfs.\n", 391 le32_to_cpu(sbp->s_rev_level), 392 le16_to_cpu(sbp->s_minor_rev_level), 393 NILFS_CURRENT_REV, NILFS_MINOR_REV); 394 return -EINVAL; 395 } 396 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 397 if (nilfs->ns_sbsize > BLOCK_SIZE) 398 return -EINVAL; 399 400 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 401 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); 402 403 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); 404 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { 405 printk(KERN_ERR "NILFS: too short segment.\n"); 406 return -EINVAL; 407 } 408 409 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); 410 nilfs->ns_r_segments_percentage = 411 le32_to_cpu(sbp->s_r_segments_percentage); 412 if (nilfs->ns_r_segments_percentage < 1 || 413 nilfs->ns_r_segments_percentage > 99) { 414 printk(KERN_ERR "NILFS: invalid reserved segments percentage.\n"); 415 return -EINVAL; 416 } 417 418 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments)); 419 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 420 return 0; 421 } 422 423 static int nilfs_valid_sb(struct nilfs_super_block *sbp) 424 { 425 static unsigned char sum[4]; 426 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 427 size_t bytes; 428 u32 crc; 429 430 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 431 return 0; 432 bytes = le16_to_cpu(sbp->s_bytes); 433 if (bytes > BLOCK_SIZE) 434 return 0; 435 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 436 sumoff); 437 crc = crc32_le(crc, sum, 4); 438 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 439 bytes - sumoff - 4); 440 return crc == le32_to_cpu(sbp->s_sum); 441 } 442 443 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 444 { 445 return offset < ((le64_to_cpu(sbp->s_nsegments) * 446 le32_to_cpu(sbp->s_blocks_per_segment)) << 447 (le32_to_cpu(sbp->s_log_block_size) + 10)); 448 } 449 450 static void nilfs_release_super_block(struct the_nilfs *nilfs) 451 { 452 int i; 453 454 for (i = 0; i < 2; i++) { 455 if (nilfs->ns_sbp[i]) { 456 brelse(nilfs->ns_sbh[i]); 457 nilfs->ns_sbh[i] = NULL; 458 nilfs->ns_sbp[i] = NULL; 459 } 460 } 461 } 462 463 void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 464 { 465 brelse(nilfs->ns_sbh[0]); 466 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 467 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 468 nilfs->ns_sbh[1] = NULL; 469 nilfs->ns_sbp[1] = NULL; 470 } 471 472 void nilfs_swap_super_block(struct the_nilfs *nilfs) 473 { 474 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 475 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 476 477 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 478 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 479 nilfs->ns_sbh[1] = tsbh; 480 nilfs->ns_sbp[1] = tsbp; 481 } 482 483 static int nilfs_load_super_block(struct the_nilfs *nilfs, 484 struct super_block *sb, int blocksize, 485 struct nilfs_super_block **sbpp) 486 { 487 struct nilfs_super_block **sbp = nilfs->ns_sbp; 488 struct buffer_head **sbh = nilfs->ns_sbh; 489 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); 490 int valid[2], swp = 0; 491 492 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 493 &sbh[0]); 494 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 495 496 if (!sbp[0]) { 497 if (!sbp[1]) { 498 printk(KERN_ERR "NILFS: unable to read superblock\n"); 499 return -EIO; 500 } 501 printk(KERN_WARNING 502 "NILFS warning: unable to read primary superblock " 503 "(blocksize = %d)\n", blocksize); 504 } else if (!sbp[1]) { 505 printk(KERN_WARNING 506 "NILFS warning: unable to read secondary superblock " 507 "(blocksize = %d)\n", blocksize); 508 } 509 510 /* 511 * Compare two super blocks and set 1 in swp if the secondary 512 * super block is valid and newer. Otherwise, set 0 in swp. 513 */ 514 valid[0] = nilfs_valid_sb(sbp[0]); 515 valid[1] = nilfs_valid_sb(sbp[1]); 516 swp = valid[1] && (!valid[0] || 517 le64_to_cpu(sbp[1]->s_last_cno) > 518 le64_to_cpu(sbp[0]->s_last_cno)); 519 520 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 521 brelse(sbh[1]); 522 sbh[1] = NULL; 523 sbp[1] = NULL; 524 valid[1] = 0; 525 swp = 0; 526 } 527 if (!valid[swp]) { 528 nilfs_release_super_block(nilfs); 529 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n", 530 sb->s_id); 531 return -EINVAL; 532 } 533 534 if (!valid[!swp]) 535 printk(KERN_WARNING "NILFS warning: broken superblock. " 536 "using spare superblock (blocksize = %d).\n", blocksize); 537 if (swp) 538 nilfs_swap_super_block(nilfs); 539 540 nilfs->ns_sbwcount = 0; 541 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 542 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); 543 *sbpp = sbp[0]; 544 return 0; 545 } 546 547 /** 548 * init_nilfs - initialize a NILFS instance. 549 * @nilfs: the_nilfs structure 550 * @sb: super block 551 * @data: mount options 552 * 553 * init_nilfs() performs common initialization per block device (e.g. 554 * reading the super block, getting disk layout information, initializing 555 * shared fields in the_nilfs). 556 * 557 * Return Value: On success, 0 is returned. On error, a negative error 558 * code is returned. 559 */ 560 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data) 561 { 562 struct nilfs_super_block *sbp; 563 int blocksize; 564 int err; 565 566 down_write(&nilfs->ns_sem); 567 568 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 569 if (!blocksize) { 570 printk(KERN_ERR "NILFS: unable to set blocksize\n"); 571 err = -EINVAL; 572 goto out; 573 } 574 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 575 if (err) 576 goto out; 577 578 err = nilfs_store_magic_and_option(sb, sbp, data); 579 if (err) 580 goto failed_sbh; 581 582 err = nilfs_check_feature_compatibility(sb, sbp); 583 if (err) 584 goto failed_sbh; 585 586 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); 587 if (blocksize < NILFS_MIN_BLOCK_SIZE || 588 blocksize > NILFS_MAX_BLOCK_SIZE) { 589 printk(KERN_ERR "NILFS: couldn't mount because of unsupported " 590 "filesystem blocksize %d\n", blocksize); 591 err = -EINVAL; 592 goto failed_sbh; 593 } 594 if (sb->s_blocksize != blocksize) { 595 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 596 597 if (blocksize < hw_blocksize) { 598 printk(KERN_ERR 599 "NILFS: blocksize %d too small for device " 600 "(sector-size = %d).\n", 601 blocksize, hw_blocksize); 602 err = -EINVAL; 603 goto failed_sbh; 604 } 605 nilfs_release_super_block(nilfs); 606 sb_set_blocksize(sb, blocksize); 607 608 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 609 if (err) 610 goto out; 611 /* not failed_sbh; sbh is released automatically 612 when reloading fails. */ 613 } 614 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 615 nilfs->ns_blocksize = blocksize; 616 617 get_random_bytes(&nilfs->ns_next_generation, 618 sizeof(nilfs->ns_next_generation)); 619 620 err = nilfs_store_disk_layout(nilfs, sbp); 621 if (err) 622 goto failed_sbh; 623 624 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 625 626 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 627 628 err = nilfs_store_log_cursor(nilfs, sbp); 629 if (err) 630 goto failed_sbh; 631 632 set_nilfs_init(nilfs); 633 err = 0; 634 out: 635 up_write(&nilfs->ns_sem); 636 return err; 637 638 failed_sbh: 639 nilfs_release_super_block(nilfs); 640 goto out; 641 } 642 643 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 644 size_t nsegs) 645 { 646 sector_t seg_start, seg_end; 647 sector_t start = 0, nblocks = 0; 648 unsigned int sects_per_block; 649 __u64 *sn; 650 int ret = 0; 651 652 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 653 bdev_logical_block_size(nilfs->ns_bdev); 654 for (sn = segnump; sn < segnump + nsegs; sn++) { 655 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 656 657 if (!nblocks) { 658 start = seg_start; 659 nblocks = seg_end - seg_start + 1; 660 } else if (start + nblocks == seg_start) { 661 nblocks += seg_end - seg_start + 1; 662 } else { 663 ret = blkdev_issue_discard(nilfs->ns_bdev, 664 start * sects_per_block, 665 nblocks * sects_per_block, 666 GFP_NOFS, 0); 667 if (ret < 0) 668 return ret; 669 nblocks = 0; 670 } 671 } 672 if (nblocks) 673 ret = blkdev_issue_discard(nilfs->ns_bdev, 674 start * sects_per_block, 675 nblocks * sects_per_block, 676 GFP_NOFS, 0); 677 return ret; 678 } 679 680 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 681 { 682 unsigned long ncleansegs; 683 684 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 685 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 686 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 687 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 688 return 0; 689 } 690 691 int nilfs_near_disk_full(struct the_nilfs *nilfs) 692 { 693 unsigned long ncleansegs, nincsegs; 694 695 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 696 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 697 nilfs->ns_blocks_per_segment + 1; 698 699 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 700 } 701 702 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 703 { 704 struct rb_node *n; 705 struct nilfs_root *root; 706 707 spin_lock(&nilfs->ns_cptree_lock); 708 n = nilfs->ns_cptree.rb_node; 709 while (n) { 710 root = rb_entry(n, struct nilfs_root, rb_node); 711 712 if (cno < root->cno) { 713 n = n->rb_left; 714 } else if (cno > root->cno) { 715 n = n->rb_right; 716 } else { 717 atomic_inc(&root->count); 718 spin_unlock(&nilfs->ns_cptree_lock); 719 return root; 720 } 721 } 722 spin_unlock(&nilfs->ns_cptree_lock); 723 724 return NULL; 725 } 726 727 struct nilfs_root * 728 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 729 { 730 struct rb_node **p, *parent; 731 struct nilfs_root *root, *new; 732 733 root = nilfs_lookup_root(nilfs, cno); 734 if (root) 735 return root; 736 737 new = kmalloc(sizeof(*root), GFP_KERNEL); 738 if (!new) 739 return NULL; 740 741 spin_lock(&nilfs->ns_cptree_lock); 742 743 p = &nilfs->ns_cptree.rb_node; 744 parent = NULL; 745 746 while (*p) { 747 parent = *p; 748 root = rb_entry(parent, struct nilfs_root, rb_node); 749 750 if (cno < root->cno) { 751 p = &(*p)->rb_left; 752 } else if (cno > root->cno) { 753 p = &(*p)->rb_right; 754 } else { 755 atomic_inc(&root->count); 756 spin_unlock(&nilfs->ns_cptree_lock); 757 kfree(new); 758 return root; 759 } 760 } 761 762 new->cno = cno; 763 new->ifile = NULL; 764 new->nilfs = nilfs; 765 atomic_set(&new->count, 1); 766 atomic_set(&new->inodes_count, 0); 767 atomic_set(&new->blocks_count, 0); 768 769 rb_link_node(&new->rb_node, parent, p); 770 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 771 772 spin_unlock(&nilfs->ns_cptree_lock); 773 774 return new; 775 } 776 777 void nilfs_put_root(struct nilfs_root *root) 778 { 779 if (atomic_dec_and_test(&root->count)) { 780 struct the_nilfs *nilfs = root->nilfs; 781 782 spin_lock(&nilfs->ns_cptree_lock); 783 rb_erase(&root->rb_node, &nilfs->ns_cptree); 784 spin_unlock(&nilfs->ns_cptree_lock); 785 if (root->ifile) 786 iput(root->ifile); 787 788 kfree(root); 789 } 790 } 791