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