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the_nilfs.c
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linux-6.19.14/fs/nilfs2/the_nilfs.c
1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * the_nilfs shared structure. 4 * 5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. 6 * 7 * Written by Ryusuke Konishi. 8 * 9 */ 10 11#include <linux/buffer_head.h> 12#include <linux/slab.h> 13#include <linux/blkdev.h> 14#include <linux/backing-dev.h> 15#include <linux/log2.h> 16#include <linux/crc32.h> 17#include "nilfs.h" 18#include "segment.h" 19#include "alloc.h" 20#include "cpfile.h" 21#include "sufile.h" 22#include "dat.h" 23#include "segbuf.h" 24 25 26static int nilfs_valid_sb(struct nilfs_super_block *sbp); 27 28void nilfs_set_last_segment(struct the_nilfs *nilfs, 29 sector_t start_blocknr, u64 seq, __u64 cno) 30{ 31 spin_lock(&nilfs->ns_last_segment_lock); 32 nilfs->ns_last_pseg = start_blocknr; 33 nilfs->ns_last_seq = seq; 34 nilfs->ns_last_cno = cno; 35 36 if (!nilfs_sb_dirty(nilfs)) { 37 if (nilfs->ns_prev_seq == nilfs->ns_last_seq) 38 goto stay_cursor; 39 40 set_nilfs_sb_dirty(nilfs); 41 } 42 nilfs->ns_prev_seq = nilfs->ns_last_seq; 43 44 stay_cursor: 45 spin_unlock(&nilfs->ns_last_segment_lock); 46} 47 48/** 49 * alloc_nilfs - allocate a nilfs object 50 * @sb: super block instance 51 * 52 * Return: a pointer to the allocated nilfs object on success, or NULL on 53 * failure. 54 */ 55struct the_nilfs *alloc_nilfs(struct super_block *sb) 56{ 57 struct the_nilfs *nilfs; 58 59 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL); 60 if (!nilfs) 61 return NULL; 62 63 nilfs->ns_sb = sb; 64 nilfs->ns_bdev = sb->s_bdev; 65 atomic_set(&nilfs->ns_ndirtyblks, 0); 66 init_rwsem(&nilfs->ns_sem); 67 mutex_init(&nilfs->ns_snapshot_mount_mutex); 68 INIT_LIST_HEAD(&nilfs->ns_dirty_files); 69 INIT_LIST_HEAD(&nilfs->ns_gc_inodes); 70 spin_lock_init(&nilfs->ns_inode_lock); 71 spin_lock_init(&nilfs->ns_last_segment_lock); 72 nilfs->ns_cptree = RB_ROOT; 73 spin_lock_init(&nilfs->ns_cptree_lock); 74 init_rwsem(&nilfs->ns_segctor_sem); 75 nilfs->ns_sb_update_freq = NILFS_SB_FREQ; 76 77 return nilfs; 78} 79 80/** 81 * destroy_nilfs - destroy nilfs object 82 * @nilfs: nilfs object to be released 83 */ 84void destroy_nilfs(struct the_nilfs *nilfs) 85{ 86 might_sleep(); 87 if (nilfs_init(nilfs)) { 88 brelse(nilfs->ns_sbh[0]); 89 brelse(nilfs->ns_sbh[1]); 90 } 91 kfree(nilfs); 92} 93 94static int nilfs_load_super_root(struct the_nilfs *nilfs, 95 struct super_block *sb, sector_t sr_block) 96{ 97 struct buffer_head *bh_sr; 98 struct nilfs_super_root *raw_sr; 99 struct nilfs_super_block **sbp = nilfs->ns_sbp; 100 struct nilfs_inode *rawi; 101 unsigned int dat_entry_size, segment_usage_size, checkpoint_size; 102 unsigned int inode_size; 103 int err; 104 105 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1); 106 if (unlikely(err)) 107 return err; 108 109 down_read(&nilfs->ns_sem); 110 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size); 111 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size); 112 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size); 113 up_read(&nilfs->ns_sem); 114 115 inode_size = nilfs->ns_inode_size; 116 117 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size); 118 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat); 119 if (err) 120 goto failed; 121 122 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size); 123 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile); 124 if (err) 125 goto failed_dat; 126 127 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size); 128 err = nilfs_sufile_read(sb, segment_usage_size, rawi, 129 &nilfs->ns_sufile); 130 if (err) 131 goto failed_cpfile; 132 133 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 134 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime); 135 136 failed: 137 brelse(bh_sr); 138 return err; 139 140 failed_cpfile: 141 iput(nilfs->ns_cpfile); 142 143 failed_dat: 144 iput(nilfs->ns_dat); 145 goto failed; 146} 147 148static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri) 149{ 150 memset(ri, 0, sizeof(*ri)); 151 INIT_LIST_HEAD(&ri->ri_used_segments); 152} 153 154static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri) 155{ 156 nilfs_dispose_segment_list(&ri->ri_used_segments); 157} 158 159/** 160 * nilfs_store_log_cursor - load log cursor from a super block 161 * @nilfs: nilfs object 162 * @sbp: buffer storing super block to be read 163 * 164 * nilfs_store_log_cursor() reads the last position of the log 165 * containing a super root from a given super block, and initializes 166 * relevant information on the nilfs object preparatory for log 167 * scanning and recovery. 168 * 169 * Return: 0 on success, or %-EINVAL if current segment number is out 170 * of range. 171 */ 172static int nilfs_store_log_cursor(struct the_nilfs *nilfs, 173 struct nilfs_super_block *sbp) 174{ 175 int ret = 0; 176 177 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg); 178 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno); 179 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq); 180 181 nilfs->ns_prev_seq = nilfs->ns_last_seq; 182 nilfs->ns_seg_seq = nilfs->ns_last_seq; 183 nilfs->ns_segnum = 184 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg); 185 nilfs->ns_cno = nilfs->ns_last_cno + 1; 186 if (nilfs->ns_segnum >= nilfs->ns_nsegments) { 187 nilfs_err(nilfs->ns_sb, 188 "pointed segment number is out of range: segnum=%llu, nsegments=%lu", 189 (unsigned long long)nilfs->ns_segnum, 190 nilfs->ns_nsegments); 191 ret = -EINVAL; 192 } 193 return ret; 194} 195 196/** 197 * nilfs_get_blocksize - get block size from raw superblock data 198 * @sb: super block instance 199 * @sbp: superblock raw data buffer 200 * @blocksize: place to store block size 201 * 202 * nilfs_get_blocksize() calculates the block size from the block size 203 * exponent information written in @sbp and stores it in @blocksize, 204 * or aborts with an error message if it's too large. 205 * 206 * Return: 0 on success, or %-EINVAL if the block size is too large. 207 */ 208static int nilfs_get_blocksize(struct super_block *sb, 209 struct nilfs_super_block *sbp, int *blocksize) 210{ 211 unsigned int shift_bits = le32_to_cpu(sbp->s_log_block_size); 212 213 if (unlikely(shift_bits > 214 ilog2(NILFS_MAX_BLOCK_SIZE) - BLOCK_SIZE_BITS)) { 215 nilfs_err(sb, "too large filesystem blocksize: 2 ^ %u KiB", 216 shift_bits); 217 return -EINVAL; 218 } 219 *blocksize = BLOCK_SIZE << shift_bits; 220 return 0; 221} 222 223/** 224 * load_nilfs - load and recover the nilfs 225 * @nilfs: the_nilfs structure to be released 226 * @sb: super block instance used to recover past segment 227 * 228 * load_nilfs() searches and load the latest super root, 229 * attaches the last segment, and does recovery if needed. 230 * The caller must call this exclusively for simultaneous mounts. 231 * 232 * Return: 0 on success, or one of the following negative error codes on 233 * failure: 234 * * %-EINVAL - No valid segment found. 235 * * %-EIO - I/O error. 236 * * %-ENOMEM - Insufficient memory available. 237 * * %-EROFS - Read only device or RO compat mode (if recovery is required) 238 */ 239int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb) 240{ 241 struct nilfs_recovery_info ri; 242 unsigned int s_flags = sb->s_flags; 243 int really_read_only = bdev_read_only(nilfs->ns_bdev); 244 int valid_fs = nilfs_valid_fs(nilfs); 245 int err; 246 247 if (!valid_fs) { 248 nilfs_warn(sb, "mounting unchecked fs"); 249 if (s_flags & SB_RDONLY) { 250 nilfs_info(sb, 251 "recovery required for readonly filesystem"); 252 nilfs_info(sb, 253 "write access will be enabled during recovery"); 254 } 255 } 256 257 nilfs_init_recovery_info(&ri); 258 259 err = nilfs_search_super_root(nilfs, &ri); 260 if (unlikely(err)) { 261 struct nilfs_super_block **sbp = nilfs->ns_sbp; 262 int blocksize; 263 264 if (err != -EINVAL) 265 goto scan_error; 266 267 if (!nilfs_valid_sb(sbp[1])) { 268 nilfs_warn(sb, 269 "unable to fall back to spare super block"); 270 goto scan_error; 271 } 272 nilfs_info(sb, "trying rollback from an earlier position"); 273 274 /* 275 * restore super block with its spare and reconfigure 276 * relevant states of the nilfs object. 277 */ 278 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 279 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed); 280 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 281 282 /* verify consistency between two super blocks */ 283 err = nilfs_get_blocksize(sb, sbp[0], &blocksize); 284 if (err) 285 goto scan_error; 286 287 if (blocksize != nilfs->ns_blocksize) { 288 nilfs_warn(sb, 289 "blocksize differs between two super blocks (%d != %d)", 290 blocksize, nilfs->ns_blocksize); 291 err = -EINVAL; 292 goto scan_error; 293 } 294 295 err = nilfs_store_log_cursor(nilfs, sbp[0]); 296 if (err) 297 goto scan_error; 298 299 /* drop clean flag to allow roll-forward and recovery */ 300 nilfs->ns_mount_state &= ~NILFS_VALID_FS; 301 valid_fs = 0; 302 303 err = nilfs_search_super_root(nilfs, &ri); 304 if (err) 305 goto scan_error; 306 } 307 308 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root); 309 if (unlikely(err)) { 310 nilfs_err(sb, "error %d while loading super root", err); 311 goto failed; 312 } 313 314 err = nilfs_sysfs_create_device_group(sb); 315 if (unlikely(err)) 316 goto sysfs_error; 317 318 if (valid_fs) 319 goto skip_recovery; 320 321 if (s_flags & SB_RDONLY) { 322 __u64 features; 323 324 if (nilfs_test_opt(nilfs, NORECOVERY)) { 325 nilfs_info(sb, 326 "norecovery option specified, skipping roll-forward recovery"); 327 goto skip_recovery; 328 } 329 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 330 ~NILFS_FEATURE_COMPAT_RO_SUPP; 331 if (features) { 332 nilfs_err(sb, 333 "couldn't proceed with recovery because of unsupported optional features (%llx)", 334 (unsigned long long)features); 335 err = -EROFS; 336 goto failed_unload; 337 } 338 if (really_read_only) { 339 nilfs_err(sb, 340 "write access unavailable, cannot proceed"); 341 err = -EROFS; 342 goto failed_unload; 343 } 344 sb->s_flags &= ~SB_RDONLY; 345 } else if (nilfs_test_opt(nilfs, NORECOVERY)) { 346 nilfs_err(sb, 347 "recovery cancelled because norecovery option was specified for a read/write mount"); 348 err = -EINVAL; 349 goto failed_unload; 350 } 351 352 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri); 353 if (err) 354 goto failed_unload; 355 356 down_write(&nilfs->ns_sem); 357 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */ 358 err = nilfs_cleanup_super(sb); 359 up_write(&nilfs->ns_sem); 360 361 if (err) { 362 nilfs_err(sb, 363 "error %d updating super block. recovery unfinished.", 364 err); 365 goto failed_unload; 366 } 367 nilfs_info(sb, "recovery complete"); 368 369 skip_recovery: 370 nilfs_clear_recovery_info(&ri); 371 sb->s_flags = s_flags; 372 return 0; 373 374 scan_error: 375 nilfs_err(sb, "error %d while searching super root", err); 376 goto failed; 377 378 failed_unload: 379 nilfs_sysfs_delete_device_group(nilfs); 380 381 sysfs_error: 382 iput(nilfs->ns_cpfile); 383 iput(nilfs->ns_sufile); 384 iput(nilfs->ns_dat); 385 386 failed: 387 nilfs_clear_recovery_info(&ri); 388 sb->s_flags = s_flags; 389 return err; 390} 391 392static unsigned long long nilfs_max_size(unsigned int blkbits) 393{ 394 unsigned int max_bits; 395 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ 396 397 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ 398 if (max_bits < 64) 399 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); 400 return res; 401} 402 403/** 404 * nilfs_nrsvsegs - calculate the number of reserved segments 405 * @nilfs: nilfs object 406 * @nsegs: total number of segments 407 * 408 * Return: Number of reserved segments. 409 */ 410unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs) 411{ 412 return max_t(unsigned long, NILFS_MIN_NRSVSEGS, 413 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage, 414 100)); 415} 416 417/** 418 * nilfs_max_segment_count - calculate the maximum number of segments 419 * @nilfs: nilfs object 420 * 421 * Return: Maximum number of segments 422 */ 423static u64 nilfs_max_segment_count(struct the_nilfs *nilfs) 424{ 425 u64 max_count = U64_MAX; 426 427 max_count = div64_ul(max_count, nilfs->ns_blocks_per_segment); 428 return min_t(u64, max_count, ULONG_MAX); 429} 430 431void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs) 432{ 433 nilfs->ns_nsegments = nsegs; 434 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs); 435} 436 437static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 438 struct nilfs_super_block *sbp) 439{ 440 u64 nsegments, nblocks; 441 442 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 443 nilfs_err(nilfs->ns_sb, 444 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).", 445 le32_to_cpu(sbp->s_rev_level), 446 le16_to_cpu(sbp->s_minor_rev_level), 447 NILFS_CURRENT_REV, NILFS_MINOR_REV); 448 return -EINVAL; 449 } 450 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 451 if (nilfs->ns_sbsize > BLOCK_SIZE) 452 return -EINVAL; 453 454 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 455 if (nilfs->ns_inode_size > nilfs->ns_blocksize) { 456 nilfs_err(nilfs->ns_sb, "too large inode size: %d bytes", 457 nilfs->ns_inode_size); 458 return -EINVAL; 459 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) { 460 nilfs_err(nilfs->ns_sb, "too small inode size: %d bytes", 461 nilfs->ns_inode_size); 462 return -EINVAL; 463 } 464 465 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); 466 if (nilfs->ns_first_ino < NILFS_USER_INO) { 467 nilfs_err(nilfs->ns_sb, 468 "too small lower limit for non-reserved inode numbers: %u", 469 nilfs->ns_first_ino); 470 return -EINVAL; 471 } 472 473 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); 474 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { 475 nilfs_err(nilfs->ns_sb, "too short segment: %lu blocks", 476 nilfs->ns_blocks_per_segment); 477 return -EINVAL; 478 } 479 480 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); 481 nilfs->ns_r_segments_percentage = 482 le32_to_cpu(sbp->s_r_segments_percentage); 483 if (nilfs->ns_r_segments_percentage < 1 || 484 nilfs->ns_r_segments_percentage > 99) { 485 nilfs_err(nilfs->ns_sb, 486 "invalid reserved segments percentage: %lu", 487 nilfs->ns_r_segments_percentage); 488 return -EINVAL; 489 } 490 491 nsegments = le64_to_cpu(sbp->s_nsegments); 492 if (nsegments > nilfs_max_segment_count(nilfs)) { 493 nilfs_err(nilfs->ns_sb, 494 "segment count %llu exceeds upper limit (%llu segments)", 495 (unsigned long long)nsegments, 496 (unsigned long long)nilfs_max_segment_count(nilfs)); 497 return -EINVAL; 498 } 499 500 nblocks = sb_bdev_nr_blocks(nilfs->ns_sb); 501 if (nblocks) { 502 u64 min_block_count = nsegments * nilfs->ns_blocks_per_segment; 503 /* 504 * To avoid failing to mount early device images without a 505 * second superblock, exclude that block count from the 506 * "min_block_count" calculation. 507 */ 508 509 if (nblocks < min_block_count) { 510 nilfs_err(nilfs->ns_sb, 511 "total number of segment blocks %llu exceeds device size (%llu blocks)", 512 (unsigned long long)min_block_count, 513 (unsigned long long)nblocks); 514 return -EINVAL; 515 } 516 } 517 518 nilfs_set_nsegments(nilfs, nsegments); 519 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 520 return 0; 521} 522 523static int nilfs_valid_sb(struct nilfs_super_block *sbp) 524{ 525 static unsigned char sum[4]; 526 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 527 size_t bytes; 528 u32 crc; 529 530 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 531 return 0; 532 bytes = le16_to_cpu(sbp->s_bytes); 533 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE) 534 return 0; 535 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 536 sumoff); 537 crc = crc32_le(crc, sum, 4); 538 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 539 bytes - sumoff - 4); 540 return crc == le32_to_cpu(sbp->s_sum); 541} 542 543/** 544 * nilfs_sb2_bad_offset - check the location of the second superblock 545 * @sbp: superblock raw data buffer 546 * @offset: byte offset of second superblock calculated from device size 547 * 548 * nilfs_sb2_bad_offset() checks if the position on the second 549 * superblock is valid or not based on the filesystem parameters 550 * stored in @sbp. If @offset points to a location within the segment 551 * area, or if the parameters themselves are not normal, it is 552 * determined to be invalid. 553 * 554 * Return: true if invalid, false if valid. 555 */ 556static bool nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 557{ 558 unsigned int shift_bits = le32_to_cpu(sbp->s_log_block_size); 559 u32 blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); 560 u64 nsegments = le64_to_cpu(sbp->s_nsegments); 561 u64 index; 562 563 if (blocks_per_segment < NILFS_SEG_MIN_BLOCKS || 564 shift_bits > ilog2(NILFS_MAX_BLOCK_SIZE) - BLOCK_SIZE_BITS) 565 return true; 566 567 index = offset >> (shift_bits + BLOCK_SIZE_BITS); 568 do_div(index, blocks_per_segment); 569 return index < nsegments; 570} 571 572static void nilfs_release_super_block(struct the_nilfs *nilfs) 573{ 574 int i; 575 576 for (i = 0; i < 2; i++) { 577 if (nilfs->ns_sbp[i]) { 578 brelse(nilfs->ns_sbh[i]); 579 nilfs->ns_sbh[i] = NULL; 580 nilfs->ns_sbp[i] = NULL; 581 } 582 } 583} 584 585void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 586{ 587 brelse(nilfs->ns_sbh[0]); 588 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 589 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 590 nilfs->ns_sbh[1] = NULL; 591 nilfs->ns_sbp[1] = NULL; 592} 593 594void nilfs_swap_super_block(struct the_nilfs *nilfs) 595{ 596 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 597 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 598 599 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 600 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 601 nilfs->ns_sbh[1] = tsbh; 602 nilfs->ns_sbp[1] = tsbp; 603} 604 605static int nilfs_load_super_block(struct the_nilfs *nilfs, 606 struct super_block *sb, int blocksize, 607 struct nilfs_super_block **sbpp) 608{ 609 struct nilfs_super_block **sbp = nilfs->ns_sbp; 610 struct buffer_head **sbh = nilfs->ns_sbh; 611 u64 sb2off, devsize = bdev_nr_bytes(nilfs->ns_bdev); 612 int valid[2], swp = 0, older; 613 614 if (devsize < NILFS_SEG_MIN_BLOCKS * NILFS_MIN_BLOCK_SIZE + 4096) { 615 nilfs_err(sb, "device size too small"); 616 return -EINVAL; 617 } 618 sb2off = NILFS_SB2_OFFSET_BYTES(devsize); 619 620 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 621 &sbh[0]); 622 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 623 624 if (!sbp[0]) { 625 if (!sbp[1]) { 626 nilfs_err(sb, "unable to read superblock"); 627 return -EIO; 628 } 629 nilfs_warn(sb, 630 "unable to read primary superblock (blocksize = %d)", 631 blocksize); 632 } else if (!sbp[1]) { 633 nilfs_warn(sb, 634 "unable to read secondary superblock (blocksize = %d)", 635 blocksize); 636 } 637 638 /* 639 * Compare two super blocks and set 1 in swp if the secondary 640 * super block is valid and newer. Otherwise, set 0 in swp. 641 */ 642 valid[0] = nilfs_valid_sb(sbp[0]); 643 valid[1] = nilfs_valid_sb(sbp[1]); 644 swp = valid[1] && (!valid[0] || 645 le64_to_cpu(sbp[1]->s_last_cno) > 646 le64_to_cpu(sbp[0]->s_last_cno)); 647 648 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 649 brelse(sbh[1]); 650 sbh[1] = NULL; 651 sbp[1] = NULL; 652 valid[1] = 0; 653 swp = 0; 654 } 655 if (!valid[swp]) { 656 nilfs_release_super_block(nilfs); 657 nilfs_err(sb, "couldn't find nilfs on the device"); 658 return -EINVAL; 659 } 660 661 if (!valid[!swp]) 662 nilfs_warn(sb, 663 "broken superblock, retrying with spare superblock (blocksize = %d)", 664 blocksize); 665 if (swp) 666 nilfs_swap_super_block(nilfs); 667 668 /* 669 * Calculate the array index of the older superblock data. 670 * If one has been dropped, set index 0 pointing to the remaining one, 671 * otherwise set index 1 pointing to the old one (including if both 672 * are the same). 673 * 674 * Divided case valid[0] valid[1] swp -> older 675 * ------------------------------------------------------------- 676 * Both SBs are invalid 0 0 N/A (Error) 677 * SB1 is invalid 0 1 1 0 678 * SB2 is invalid 1 0 0 0 679 * SB2 is newer 1 1 1 0 680 * SB2 is older or the same 1 1 0 1 681 */ 682 older = valid[1] ^ swp; 683 684 nilfs->ns_sbwcount = 0; 685 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 686 nilfs->ns_prot_seq = le64_to_cpu(sbp[older]->s_last_seq); 687 *sbpp = sbp[0]; 688 return 0; 689} 690 691/** 692 * init_nilfs - initialize a NILFS instance. 693 * @nilfs: the_nilfs structure 694 * @sb: super block 695 * 696 * init_nilfs() performs common initialization per block device (e.g. 697 * reading the super block, getting disk layout information, initializing 698 * shared fields in the_nilfs). 699 * 700 * Return: 0 on success, or a negative error code on failure. 701 */ 702int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb) 703{ 704 struct nilfs_super_block *sbp; 705 int blocksize; 706 int err; 707 708 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 709 if (!blocksize) { 710 nilfs_err(sb, "unable to set blocksize"); 711 err = -EINVAL; 712 goto out; 713 } 714 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 715 if (err) 716 goto out; 717 718 err = nilfs_store_magic(sb, sbp); 719 if (err) 720 goto failed_sbh; 721 722 err = nilfs_check_feature_compatibility(sb, sbp); 723 if (err) 724 goto failed_sbh; 725 726 err = nilfs_get_blocksize(sb, sbp, &blocksize); 727 if (err) 728 goto failed_sbh; 729 730 if (blocksize < NILFS_MIN_BLOCK_SIZE) { 731 nilfs_err(sb, 732 "couldn't mount because of unsupported filesystem blocksize %d", 733 blocksize); 734 err = -EINVAL; 735 goto failed_sbh; 736 } 737 if (sb->s_blocksize != blocksize) { 738 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 739 740 if (blocksize < hw_blocksize) { 741 nilfs_err(sb, 742 "blocksize %d too small for device (sector-size = %d)", 743 blocksize, hw_blocksize); 744 err = -EINVAL; 745 goto failed_sbh; 746 } 747 nilfs_release_super_block(nilfs); 748 if (!sb_set_blocksize(sb, blocksize)) { 749 nilfs_err(sb, "bad blocksize %d", blocksize); 750 err = -EINVAL; 751 goto out; 752 } 753 754 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 755 if (err) 756 goto out; 757 /* 758 * Not to failed_sbh; sbh is released automatically 759 * when reloading fails. 760 */ 761 } 762 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 763 nilfs->ns_blocksize = blocksize; 764 765 err = nilfs_store_disk_layout(nilfs, sbp); 766 if (err) 767 goto failed_sbh; 768 769 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 770 771 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 772 773 err = nilfs_store_log_cursor(nilfs, sbp); 774 if (err) 775 goto failed_sbh; 776 777 set_nilfs_init(nilfs); 778 err = 0; 779 out: 780 return err; 781 782 failed_sbh: 783 nilfs_release_super_block(nilfs); 784 goto out; 785} 786 787int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 788 size_t nsegs) 789{ 790 sector_t seg_start, seg_end; 791 sector_t start = 0, nblocks = 0; 792 unsigned int sects_per_block; 793 __u64 *sn; 794 int ret = 0; 795 796 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 797 bdev_logical_block_size(nilfs->ns_bdev); 798 for (sn = segnump; sn < segnump + nsegs; sn++) { 799 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 800 801 if (!nblocks) { 802 start = seg_start; 803 nblocks = seg_end - seg_start + 1; 804 } else if (start + nblocks == seg_start) { 805 nblocks += seg_end - seg_start + 1; 806 } else { 807 ret = blkdev_issue_discard(nilfs->ns_bdev, 808 start * sects_per_block, 809 nblocks * sects_per_block, 810 GFP_NOFS); 811 if (ret < 0) 812 return ret; 813 nblocks = 0; 814 } 815 } 816 if (nblocks) 817 ret = blkdev_issue_discard(nilfs->ns_bdev, 818 start * sects_per_block, 819 nblocks * sects_per_block, 820 GFP_NOFS); 821 return ret; 822} 823 824int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 825{ 826 unsigned long ncleansegs; 827 828 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 829 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 830 return 0; 831} 832 833int nilfs_near_disk_full(struct the_nilfs *nilfs) 834{ 835 unsigned long ncleansegs, nincsegs; 836 837 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 838 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 839 nilfs->ns_blocks_per_segment + 1; 840 841 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 842} 843 844struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 845{ 846 struct rb_node *n; 847 struct nilfs_root *root; 848 849 spin_lock(&nilfs->ns_cptree_lock); 850 n = nilfs->ns_cptree.rb_node; 851 while (n) { 852 root = rb_entry(n, struct nilfs_root, rb_node); 853 854 if (cno < root->cno) { 855 n = n->rb_left; 856 } else if (cno > root->cno) { 857 n = n->rb_right; 858 } else { 859 refcount_inc(&root->count); 860 spin_unlock(&nilfs->ns_cptree_lock); 861 return root; 862 } 863 } 864 spin_unlock(&nilfs->ns_cptree_lock); 865 866 return NULL; 867} 868 869struct nilfs_root * 870nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 871{ 872 struct rb_node **p, *parent; 873 struct nilfs_root *root, *new; 874 int err; 875 876 root = nilfs_lookup_root(nilfs, cno); 877 if (root) 878 return root; 879 880 new = kzalloc(sizeof(*root), GFP_KERNEL); 881 if (!new) 882 return NULL; 883 884 spin_lock(&nilfs->ns_cptree_lock); 885 886 p = &nilfs->ns_cptree.rb_node; 887 parent = NULL; 888 889 while (*p) { 890 parent = *p; 891 root = rb_entry(parent, struct nilfs_root, rb_node); 892 893 if (cno < root->cno) { 894 p = &(*p)->rb_left; 895 } else if (cno > root->cno) { 896 p = &(*p)->rb_right; 897 } else { 898 refcount_inc(&root->count); 899 spin_unlock(&nilfs->ns_cptree_lock); 900 kfree(new); 901 return root; 902 } 903 } 904 905 new->cno = cno; 906 new->ifile = NULL; 907 new->nilfs = nilfs; 908 refcount_set(&new->count, 1); 909 atomic64_set(&new->inodes_count, 0); 910 atomic64_set(&new->blocks_count, 0); 911 912 rb_link_node(&new->rb_node, parent, p); 913 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 914 915 spin_unlock(&nilfs->ns_cptree_lock); 916 917 err = nilfs_sysfs_create_snapshot_group(new); 918 if (err) { 919 kfree(new); 920 new = NULL; 921 } 922 923 return new; 924} 925 926void nilfs_put_root(struct nilfs_root *root) 927{ 928 struct the_nilfs *nilfs = root->nilfs; 929 930 if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) { 931 rb_erase(&root->rb_node, &nilfs->ns_cptree); 932 spin_unlock(&nilfs->ns_cptree_lock); 933 934 nilfs_sysfs_delete_snapshot_group(root); 935 iput(root->ifile); 936 937 kfree(root); 938 } 939}
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