1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * the_nilfs.c - 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/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_next_gen_lock); 72 spin_lock_init(&nilfs->ns_last_segment_lock); 73 nilfs->ns_cptree = RB_ROOT; 74 spin_lock_init(&nilfs->ns_cptree_lock); 75 init_rwsem(&nilfs->ns_segctor_sem); 76 nilfs->ns_sb_update_freq = NILFS_SB_FREQ; 77 78 return nilfs; 79 } 80 81 /** 82 * destroy_nilfs - destroy nilfs object 83 * @nilfs: nilfs object to be released 84 */ 85 void destroy_nilfs(struct the_nilfs *nilfs) 86 { 87 might_sleep(); 88 if (nilfs_init(nilfs)) { 89 nilfs_sysfs_delete_device_group(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 * load_nilfs - load and recover the nilfs 197 * @nilfs: the_nilfs structure to be released 198 * @sb: super block instance used to recover past segment 199 * 200 * load_nilfs() searches and load the latest super root, 201 * attaches the last segment, and does recovery if needed. 202 * The caller must call this exclusively for simultaneous mounts. 203 */ 204 int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb) 205 { 206 struct nilfs_recovery_info ri; 207 unsigned int s_flags = sb->s_flags; 208 int really_read_only = bdev_read_only(nilfs->ns_bdev); 209 int valid_fs = nilfs_valid_fs(nilfs); 210 int err; 211 212 if (!valid_fs) { 213 nilfs_warn(sb, "mounting unchecked fs"); 214 if (s_flags & SB_RDONLY) { 215 nilfs_info(sb, 216 "recovery required for readonly filesystem"); 217 nilfs_info(sb, 218 "write access will be enabled during recovery"); 219 } 220 } 221 222 nilfs_init_recovery_info(&ri); 223 224 err = nilfs_search_super_root(nilfs, &ri); 225 if (unlikely(err)) { 226 struct nilfs_super_block **sbp = nilfs->ns_sbp; 227 int blocksize; 228 229 if (err != -EINVAL) 230 goto scan_error; 231 232 if (!nilfs_valid_sb(sbp[1])) { 233 nilfs_warn(sb, 234 "unable to fall back to spare super block"); 235 goto scan_error; 236 } 237 nilfs_info(sb, "trying rollback from an earlier position"); 238 239 /* 240 * restore super block with its spare and reconfigure 241 * relevant states of the nilfs object. 242 */ 243 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 244 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed); 245 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 246 247 /* verify consistency between two super blocks */ 248 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size); 249 if (blocksize != nilfs->ns_blocksize) { 250 nilfs_warn(sb, 251 "blocksize differs between two super blocks (%d != %d)", 252 blocksize, nilfs->ns_blocksize); 253 goto scan_error; 254 } 255 256 err = nilfs_store_log_cursor(nilfs, sbp[0]); 257 if (err) 258 goto scan_error; 259 260 /* drop clean flag to allow roll-forward and recovery */ 261 nilfs->ns_mount_state &= ~NILFS_VALID_FS; 262 valid_fs = 0; 263 264 err = nilfs_search_super_root(nilfs, &ri); 265 if (err) 266 goto scan_error; 267 } 268 269 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root); 270 if (unlikely(err)) { 271 nilfs_err(sb, "error %d while loading super root", err); 272 goto failed; 273 } 274 275 if (valid_fs) 276 goto skip_recovery; 277 278 if (s_flags & SB_RDONLY) { 279 __u64 features; 280 281 if (nilfs_test_opt(nilfs, NORECOVERY)) { 282 nilfs_info(sb, 283 "norecovery option specified, skipping roll-forward recovery"); 284 goto skip_recovery; 285 } 286 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 287 ~NILFS_FEATURE_COMPAT_RO_SUPP; 288 if (features) { 289 nilfs_err(sb, 290 "couldn't proceed with recovery because of unsupported optional features (%llx)", 291 (unsigned long long)features); 292 err = -EROFS; 293 goto failed_unload; 294 } 295 if (really_read_only) { 296 nilfs_err(sb, 297 "write access unavailable, cannot proceed"); 298 err = -EROFS; 299 goto failed_unload; 300 } 301 sb->s_flags &= ~SB_RDONLY; 302 } else if (nilfs_test_opt(nilfs, NORECOVERY)) { 303 nilfs_err(sb, 304 "recovery cancelled because norecovery option was specified for a read/write mount"); 305 err = -EINVAL; 306 goto failed_unload; 307 } 308 309 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri); 310 if (err) 311 goto failed_unload; 312 313 down_write(&nilfs->ns_sem); 314 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */ 315 err = nilfs_cleanup_super(sb); 316 up_write(&nilfs->ns_sem); 317 318 if (err) { 319 nilfs_err(sb, 320 "error %d updating super block. recovery unfinished.", 321 err); 322 goto failed_unload; 323 } 324 nilfs_info(sb, "recovery complete"); 325 326 skip_recovery: 327 nilfs_clear_recovery_info(&ri); 328 sb->s_flags = s_flags; 329 return 0; 330 331 scan_error: 332 nilfs_err(sb, "error %d while searching super root", err); 333 goto failed; 334 335 failed_unload: 336 iput(nilfs->ns_cpfile); 337 iput(nilfs->ns_sufile); 338 iput(nilfs->ns_dat); 339 340 failed: 341 nilfs_clear_recovery_info(&ri); 342 sb->s_flags = s_flags; 343 return err; 344 } 345 346 static unsigned long long nilfs_max_size(unsigned int blkbits) 347 { 348 unsigned int max_bits; 349 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ 350 351 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ 352 if (max_bits < 64) 353 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); 354 return res; 355 } 356 357 /** 358 * nilfs_nrsvsegs - calculate the number of reserved segments 359 * @nilfs: nilfs object 360 * @nsegs: total number of segments 361 */ 362 unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs) 363 { 364 return max_t(unsigned long, NILFS_MIN_NRSVSEGS, 365 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage, 366 100)); 367 } 368 369 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs) 370 { 371 nilfs->ns_nsegments = nsegs; 372 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs); 373 } 374 375 static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 376 struct nilfs_super_block *sbp) 377 { 378 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 379 nilfs_err(nilfs->ns_sb, 380 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).", 381 le32_to_cpu(sbp->s_rev_level), 382 le16_to_cpu(sbp->s_minor_rev_level), 383 NILFS_CURRENT_REV, NILFS_MINOR_REV); 384 return -EINVAL; 385 } 386 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 387 if (nilfs->ns_sbsize > BLOCK_SIZE) 388 return -EINVAL; 389 390 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 391 if (nilfs->ns_inode_size > nilfs->ns_blocksize) { 392 nilfs_err(nilfs->ns_sb, "too large inode size: %d bytes", 393 nilfs->ns_inode_size); 394 return -EINVAL; 395 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) { 396 nilfs_err(nilfs->ns_sb, "too small inode size: %d bytes", 397 nilfs->ns_inode_size); 398 return -EINVAL; 399 } 400 401 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 nilfs_err(nilfs->ns_sb, "too short segment: %lu blocks", 406 nilfs->ns_blocks_per_segment); 407 return -EINVAL; 408 } 409 410 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); 411 nilfs->ns_r_segments_percentage = 412 le32_to_cpu(sbp->s_r_segments_percentage); 413 if (nilfs->ns_r_segments_percentage < 1 || 414 nilfs->ns_r_segments_percentage > 99) { 415 nilfs_err(nilfs->ns_sb, 416 "invalid reserved segments percentage: %lu", 417 nilfs->ns_r_segments_percentage); 418 return -EINVAL; 419 } 420 421 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments)); 422 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 423 return 0; 424 } 425 426 static int nilfs_valid_sb(struct nilfs_super_block *sbp) 427 { 428 static unsigned char sum[4]; 429 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 430 size_t bytes; 431 u32 crc; 432 433 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 434 return 0; 435 bytes = le16_to_cpu(sbp->s_bytes); 436 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE) 437 return 0; 438 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 439 sumoff); 440 crc = crc32_le(crc, sum, 4); 441 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 442 bytes - sumoff - 4); 443 return crc == le32_to_cpu(sbp->s_sum); 444 } 445 446 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 447 { 448 return offset < ((le64_to_cpu(sbp->s_nsegments) * 449 le32_to_cpu(sbp->s_blocks_per_segment)) << 450 (le32_to_cpu(sbp->s_log_block_size) + 10)); 451 } 452 453 static void nilfs_release_super_block(struct the_nilfs *nilfs) 454 { 455 int i; 456 457 for (i = 0; i < 2; i++) { 458 if (nilfs->ns_sbp[i]) { 459 brelse(nilfs->ns_sbh[i]); 460 nilfs->ns_sbh[i] = NULL; 461 nilfs->ns_sbp[i] = NULL; 462 } 463 } 464 } 465 466 void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 467 { 468 brelse(nilfs->ns_sbh[0]); 469 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 470 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 471 nilfs->ns_sbh[1] = NULL; 472 nilfs->ns_sbp[1] = NULL; 473 } 474 475 void nilfs_swap_super_block(struct the_nilfs *nilfs) 476 { 477 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 478 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 479 480 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 481 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 482 nilfs->ns_sbh[1] = tsbh; 483 nilfs->ns_sbp[1] = tsbp; 484 } 485 486 static int nilfs_load_super_block(struct the_nilfs *nilfs, 487 struct super_block *sb, int blocksize, 488 struct nilfs_super_block **sbpp) 489 { 490 struct nilfs_super_block **sbp = nilfs->ns_sbp; 491 struct buffer_head **sbh = nilfs->ns_sbh; 492 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); 493 int valid[2], swp = 0; 494 495 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 496 &sbh[0]); 497 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 498 499 if (!sbp[0]) { 500 if (!sbp[1]) { 501 nilfs_err(sb, "unable to read superblock"); 502 return -EIO; 503 } 504 nilfs_warn(sb, 505 "unable to read primary superblock (blocksize = %d)", 506 blocksize); 507 } else if (!sbp[1]) { 508 nilfs_warn(sb, 509 "unable to read secondary superblock (blocksize = %d)", 510 blocksize); 511 } 512 513 /* 514 * Compare two super blocks and set 1 in swp if the secondary 515 * super block is valid and newer. Otherwise, set 0 in swp. 516 */ 517 valid[0] = nilfs_valid_sb(sbp[0]); 518 valid[1] = nilfs_valid_sb(sbp[1]); 519 swp = valid[1] && (!valid[0] || 520 le64_to_cpu(sbp[1]->s_last_cno) > 521 le64_to_cpu(sbp[0]->s_last_cno)); 522 523 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 524 brelse(sbh[1]); 525 sbh[1] = NULL; 526 sbp[1] = NULL; 527 valid[1] = 0; 528 swp = 0; 529 } 530 if (!valid[swp]) { 531 nilfs_release_super_block(nilfs); 532 nilfs_err(sb, "couldn't find nilfs on the device"); 533 return -EINVAL; 534 } 535 536 if (!valid[!swp]) 537 nilfs_warn(sb, 538 "broken superblock, retrying with spare superblock (blocksize = %d)", 539 blocksize); 540 if (swp) 541 nilfs_swap_super_block(nilfs); 542 543 nilfs->ns_sbwcount = 0; 544 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 545 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); 546 *sbpp = sbp[0]; 547 return 0; 548 } 549 550 /** 551 * init_nilfs - initialize a NILFS instance. 552 * @nilfs: the_nilfs structure 553 * @sb: super block 554 * @data: mount options 555 * 556 * init_nilfs() performs common initialization per block device (e.g. 557 * reading the super block, getting disk layout information, initializing 558 * shared fields in the_nilfs). 559 * 560 * Return Value: On success, 0 is returned. On error, a negative error 561 * code is returned. 562 */ 563 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data) 564 { 565 struct nilfs_super_block *sbp; 566 int blocksize; 567 int err; 568 569 down_write(&nilfs->ns_sem); 570 571 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 572 if (!blocksize) { 573 nilfs_err(sb, "unable to set blocksize"); 574 err = -EINVAL; 575 goto out; 576 } 577 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 578 if (err) 579 goto out; 580 581 err = nilfs_store_magic_and_option(sb, sbp, data); 582 if (err) 583 goto failed_sbh; 584 585 err = nilfs_check_feature_compatibility(sb, sbp); 586 if (err) 587 goto failed_sbh; 588 589 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); 590 if (blocksize < NILFS_MIN_BLOCK_SIZE || 591 blocksize > NILFS_MAX_BLOCK_SIZE) { 592 nilfs_err(sb, 593 "couldn't mount because of unsupported filesystem blocksize %d", 594 blocksize); 595 err = -EINVAL; 596 goto failed_sbh; 597 } 598 if (sb->s_blocksize != blocksize) { 599 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 600 601 if (blocksize < hw_blocksize) { 602 nilfs_err(sb, 603 "blocksize %d too small for device (sector-size = %d)", 604 blocksize, hw_blocksize); 605 err = -EINVAL; 606 goto failed_sbh; 607 } 608 nilfs_release_super_block(nilfs); 609 sb_set_blocksize(sb, blocksize); 610 611 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 612 if (err) 613 goto out; 614 /* 615 * Not to failed_sbh; sbh is released automatically 616 * when reloading fails. 617 */ 618 } 619 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 620 nilfs->ns_blocksize = blocksize; 621 622 get_random_bytes(&nilfs->ns_next_generation, 623 sizeof(nilfs->ns_next_generation)); 624 625 err = nilfs_store_disk_layout(nilfs, sbp); 626 if (err) 627 goto failed_sbh; 628 629 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 630 631 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 632 633 err = nilfs_store_log_cursor(nilfs, sbp); 634 if (err) 635 goto failed_sbh; 636 637 err = nilfs_sysfs_create_device_group(sb); 638 if (err) 639 goto failed_sbh; 640 641 set_nilfs_init(nilfs); 642 err = 0; 643 out: 644 up_write(&nilfs->ns_sem); 645 return err; 646 647 failed_sbh: 648 nilfs_release_super_block(nilfs); 649 goto out; 650 } 651 652 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 653 size_t nsegs) 654 { 655 sector_t seg_start, seg_end; 656 sector_t start = 0, nblocks = 0; 657 unsigned int sects_per_block; 658 __u64 *sn; 659 int ret = 0; 660 661 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 662 bdev_logical_block_size(nilfs->ns_bdev); 663 for (sn = segnump; sn < segnump + nsegs; sn++) { 664 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 665 666 if (!nblocks) { 667 start = seg_start; 668 nblocks = seg_end - seg_start + 1; 669 } else if (start + nblocks == seg_start) { 670 nblocks += seg_end - seg_start + 1; 671 } else { 672 ret = blkdev_issue_discard(nilfs->ns_bdev, 673 start * sects_per_block, 674 nblocks * sects_per_block, 675 GFP_NOFS, 0); 676 if (ret < 0) 677 return ret; 678 nblocks = 0; 679 } 680 } 681 if (nblocks) 682 ret = blkdev_issue_discard(nilfs->ns_bdev, 683 start * sects_per_block, 684 nblocks * sects_per_block, 685 GFP_NOFS, 0); 686 return ret; 687 } 688 689 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 690 { 691 unsigned long ncleansegs; 692 693 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 694 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 695 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 696 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 697 return 0; 698 } 699 700 int nilfs_near_disk_full(struct the_nilfs *nilfs) 701 { 702 unsigned long ncleansegs, nincsegs; 703 704 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 705 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 706 nilfs->ns_blocks_per_segment + 1; 707 708 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 709 } 710 711 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 712 { 713 struct rb_node *n; 714 struct nilfs_root *root; 715 716 spin_lock(&nilfs->ns_cptree_lock); 717 n = nilfs->ns_cptree.rb_node; 718 while (n) { 719 root = rb_entry(n, struct nilfs_root, rb_node); 720 721 if (cno < root->cno) { 722 n = n->rb_left; 723 } else if (cno > root->cno) { 724 n = n->rb_right; 725 } else { 726 refcount_inc(&root->count); 727 spin_unlock(&nilfs->ns_cptree_lock); 728 return root; 729 } 730 } 731 spin_unlock(&nilfs->ns_cptree_lock); 732 733 return NULL; 734 } 735 736 struct nilfs_root * 737 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 738 { 739 struct rb_node **p, *parent; 740 struct nilfs_root *root, *new; 741 int err; 742 743 root = nilfs_lookup_root(nilfs, cno); 744 if (root) 745 return root; 746 747 new = kzalloc(sizeof(*root), GFP_KERNEL); 748 if (!new) 749 return NULL; 750 751 spin_lock(&nilfs->ns_cptree_lock); 752 753 p = &nilfs->ns_cptree.rb_node; 754 parent = NULL; 755 756 while (*p) { 757 parent = *p; 758 root = rb_entry(parent, struct nilfs_root, rb_node); 759 760 if (cno < root->cno) { 761 p = &(*p)->rb_left; 762 } else if (cno > root->cno) { 763 p = &(*p)->rb_right; 764 } else { 765 refcount_inc(&root->count); 766 spin_unlock(&nilfs->ns_cptree_lock); 767 kfree(new); 768 return root; 769 } 770 } 771 772 new->cno = cno; 773 new->ifile = NULL; 774 new->nilfs = nilfs; 775 refcount_set(&new->count, 1); 776 atomic64_set(&new->inodes_count, 0); 777 atomic64_set(&new->blocks_count, 0); 778 779 rb_link_node(&new->rb_node, parent, p); 780 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 781 782 spin_unlock(&nilfs->ns_cptree_lock); 783 784 err = nilfs_sysfs_create_snapshot_group(new); 785 if (err) { 786 kfree(new); 787 new = NULL; 788 } 789 790 return new; 791 } 792 793 void nilfs_put_root(struct nilfs_root *root) 794 { 795 struct the_nilfs *nilfs = root->nilfs; 796 797 if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) { 798 rb_erase(&root->rb_node, &nilfs->ns_cptree); 799 spin_unlock(&nilfs->ns_cptree_lock); 800 801 nilfs_sysfs_delete_snapshot_group(root); 802 iput(root->ifile); 803 804 kfree(root); 805 } 806 } 807