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