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_msg(nilfs->ns_sb, KERN_ERR, 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 isntance 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_msg(sb, KERN_WARNING, "mounting unchecked fs"); 214 if (s_flags & SB_RDONLY) { 215 nilfs_msg(sb, KERN_INFO, 216 "recovery required for readonly filesystem"); 217 nilfs_msg(sb, KERN_INFO, 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_msg(sb, KERN_WARNING, 234 "unable to fall back to spare super block"); 235 goto scan_error; 236 } 237 nilfs_msg(sb, KERN_INFO, 238 "trying rollback from an earlier position"); 239 240 /* 241 * restore super block with its spare and reconfigure 242 * relevant states of the nilfs object. 243 */ 244 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 245 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed); 246 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 247 248 /* verify consistency between two super blocks */ 249 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size); 250 if (blocksize != nilfs->ns_blocksize) { 251 nilfs_msg(sb, KERN_WARNING, 252 "blocksize differs between two super blocks (%d != %d)", 253 blocksize, nilfs->ns_blocksize); 254 goto scan_error; 255 } 256 257 err = nilfs_store_log_cursor(nilfs, sbp[0]); 258 if (err) 259 goto scan_error; 260 261 /* drop clean flag to allow roll-forward and recovery */ 262 nilfs->ns_mount_state &= ~NILFS_VALID_FS; 263 valid_fs = 0; 264 265 err = nilfs_search_super_root(nilfs, &ri); 266 if (err) 267 goto scan_error; 268 } 269 270 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root); 271 if (unlikely(err)) { 272 nilfs_msg(sb, KERN_ERR, "error %d while loading super root", 273 err); 274 goto failed; 275 } 276 277 if (valid_fs) 278 goto skip_recovery; 279 280 if (s_flags & SB_RDONLY) { 281 __u64 features; 282 283 if (nilfs_test_opt(nilfs, NORECOVERY)) { 284 nilfs_msg(sb, KERN_INFO, 285 "norecovery option specified, skipping roll-forward recovery"); 286 goto skip_recovery; 287 } 288 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 289 ~NILFS_FEATURE_COMPAT_RO_SUPP; 290 if (features) { 291 nilfs_msg(sb, KERN_ERR, 292 "couldn't proceed with recovery because of unsupported optional features (%llx)", 293 (unsigned long long)features); 294 err = -EROFS; 295 goto failed_unload; 296 } 297 if (really_read_only) { 298 nilfs_msg(sb, KERN_ERR, 299 "write access unavailable, cannot proceed"); 300 err = -EROFS; 301 goto failed_unload; 302 } 303 sb->s_flags &= ~SB_RDONLY; 304 } else if (nilfs_test_opt(nilfs, NORECOVERY)) { 305 nilfs_msg(sb, KERN_ERR, 306 "recovery cancelled because norecovery option was specified for a read/write mount"); 307 err = -EINVAL; 308 goto failed_unload; 309 } 310 311 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri); 312 if (err) 313 goto failed_unload; 314 315 down_write(&nilfs->ns_sem); 316 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */ 317 err = nilfs_cleanup_super(sb); 318 up_write(&nilfs->ns_sem); 319 320 if (err) { 321 nilfs_msg(sb, KERN_ERR, 322 "error %d updating super block. recovery unfinished.", 323 err); 324 goto failed_unload; 325 } 326 nilfs_msg(sb, KERN_INFO, "recovery complete"); 327 328 skip_recovery: 329 nilfs_clear_recovery_info(&ri); 330 sb->s_flags = s_flags; 331 return 0; 332 333 scan_error: 334 nilfs_msg(sb, KERN_ERR, "error %d while searching super root", err); 335 goto failed; 336 337 failed_unload: 338 iput(nilfs->ns_cpfile); 339 iput(nilfs->ns_sufile); 340 iput(nilfs->ns_dat); 341 342 failed: 343 nilfs_clear_recovery_info(&ri); 344 sb->s_flags = s_flags; 345 return err; 346 } 347 348 static unsigned long long nilfs_max_size(unsigned int blkbits) 349 { 350 unsigned int max_bits; 351 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ 352 353 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ 354 if (max_bits < 64) 355 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); 356 return res; 357 } 358 359 /** 360 * nilfs_nrsvsegs - calculate the number of reserved segments 361 * @nilfs: nilfs object 362 * @nsegs: total number of segments 363 */ 364 unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs) 365 { 366 return max_t(unsigned long, NILFS_MIN_NRSVSEGS, 367 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage, 368 100)); 369 } 370 371 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs) 372 { 373 nilfs->ns_nsegments = nsegs; 374 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs); 375 } 376 377 static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 378 struct nilfs_super_block *sbp) 379 { 380 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 381 nilfs_msg(nilfs->ns_sb, KERN_ERR, 382 "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).", 383 le32_to_cpu(sbp->s_rev_level), 384 le16_to_cpu(sbp->s_minor_rev_level), 385 NILFS_CURRENT_REV, NILFS_MINOR_REV); 386 return -EINVAL; 387 } 388 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 389 if (nilfs->ns_sbsize > BLOCK_SIZE) 390 return -EINVAL; 391 392 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 393 if (nilfs->ns_inode_size > nilfs->ns_blocksize) { 394 nilfs_msg(nilfs->ns_sb, KERN_ERR, 395 "too large inode size: %d bytes", 396 nilfs->ns_inode_size); 397 return -EINVAL; 398 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) { 399 nilfs_msg(nilfs->ns_sb, KERN_ERR, 400 "too small inode size: %d bytes", 401 nilfs->ns_inode_size); 402 return -EINVAL; 403 } 404 405 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); 406 407 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); 408 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { 409 nilfs_msg(nilfs->ns_sb, KERN_ERR, 410 "too short segment: %lu blocks", 411 nilfs->ns_blocks_per_segment); 412 return -EINVAL; 413 } 414 415 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); 416 nilfs->ns_r_segments_percentage = 417 le32_to_cpu(sbp->s_r_segments_percentage); 418 if (nilfs->ns_r_segments_percentage < 1 || 419 nilfs->ns_r_segments_percentage > 99) { 420 nilfs_msg(nilfs->ns_sb, KERN_ERR, 421 "invalid reserved segments percentage: %lu", 422 nilfs->ns_r_segments_percentage); 423 return -EINVAL; 424 } 425 426 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments)); 427 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 428 return 0; 429 } 430 431 static int nilfs_valid_sb(struct nilfs_super_block *sbp) 432 { 433 static unsigned char sum[4]; 434 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 435 size_t bytes; 436 u32 crc; 437 438 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 439 return 0; 440 bytes = le16_to_cpu(sbp->s_bytes); 441 if (bytes < sumoff + 4 || bytes > BLOCK_SIZE) 442 return 0; 443 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 444 sumoff); 445 crc = crc32_le(crc, sum, 4); 446 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 447 bytes - sumoff - 4); 448 return crc == le32_to_cpu(sbp->s_sum); 449 } 450 451 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 452 { 453 return offset < ((le64_to_cpu(sbp->s_nsegments) * 454 le32_to_cpu(sbp->s_blocks_per_segment)) << 455 (le32_to_cpu(sbp->s_log_block_size) + 10)); 456 } 457 458 static void nilfs_release_super_block(struct the_nilfs *nilfs) 459 { 460 int i; 461 462 for (i = 0; i < 2; i++) { 463 if (nilfs->ns_sbp[i]) { 464 brelse(nilfs->ns_sbh[i]); 465 nilfs->ns_sbh[i] = NULL; 466 nilfs->ns_sbp[i] = NULL; 467 } 468 } 469 } 470 471 void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 472 { 473 brelse(nilfs->ns_sbh[0]); 474 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 475 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 476 nilfs->ns_sbh[1] = NULL; 477 nilfs->ns_sbp[1] = NULL; 478 } 479 480 void nilfs_swap_super_block(struct the_nilfs *nilfs) 481 { 482 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 483 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 484 485 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 486 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 487 nilfs->ns_sbh[1] = tsbh; 488 nilfs->ns_sbp[1] = tsbp; 489 } 490 491 static int nilfs_load_super_block(struct the_nilfs *nilfs, 492 struct super_block *sb, int blocksize, 493 struct nilfs_super_block **sbpp) 494 { 495 struct nilfs_super_block **sbp = nilfs->ns_sbp; 496 struct buffer_head **sbh = nilfs->ns_sbh; 497 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); 498 int valid[2], swp = 0; 499 500 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 501 &sbh[0]); 502 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 503 504 if (!sbp[0]) { 505 if (!sbp[1]) { 506 nilfs_msg(sb, KERN_ERR, "unable to read superblock"); 507 return -EIO; 508 } 509 nilfs_msg(sb, KERN_WARNING, 510 "unable to read primary superblock (blocksize = %d)", 511 blocksize); 512 } else if (!sbp[1]) { 513 nilfs_msg(sb, KERN_WARNING, 514 "unable to read secondary superblock (blocksize = %d)", 515 blocksize); 516 } 517 518 /* 519 * Compare two super blocks and set 1 in swp if the secondary 520 * super block is valid and newer. Otherwise, set 0 in swp. 521 */ 522 valid[0] = nilfs_valid_sb(sbp[0]); 523 valid[1] = nilfs_valid_sb(sbp[1]); 524 swp = valid[1] && (!valid[0] || 525 le64_to_cpu(sbp[1]->s_last_cno) > 526 le64_to_cpu(sbp[0]->s_last_cno)); 527 528 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 529 brelse(sbh[1]); 530 sbh[1] = NULL; 531 sbp[1] = NULL; 532 valid[1] = 0; 533 swp = 0; 534 } 535 if (!valid[swp]) { 536 nilfs_release_super_block(nilfs); 537 nilfs_msg(sb, KERN_ERR, "couldn't find nilfs on the device"); 538 return -EINVAL; 539 } 540 541 if (!valid[!swp]) 542 nilfs_msg(sb, KERN_WARNING, 543 "broken superblock, retrying with spare superblock (blocksize = %d)", 544 blocksize); 545 if (swp) 546 nilfs_swap_super_block(nilfs); 547 548 nilfs->ns_sbwcount = 0; 549 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 550 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); 551 *sbpp = sbp[0]; 552 return 0; 553 } 554 555 /** 556 * init_nilfs - initialize a NILFS instance. 557 * @nilfs: the_nilfs structure 558 * @sb: super block 559 * @data: mount options 560 * 561 * init_nilfs() performs common initialization per block device (e.g. 562 * reading the super block, getting disk layout information, initializing 563 * shared fields in the_nilfs). 564 * 565 * Return Value: On success, 0 is returned. On error, a negative error 566 * code is returned. 567 */ 568 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data) 569 { 570 struct nilfs_super_block *sbp; 571 int blocksize; 572 int err; 573 574 down_write(&nilfs->ns_sem); 575 576 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 577 if (!blocksize) { 578 nilfs_msg(sb, KERN_ERR, "unable to set blocksize"); 579 err = -EINVAL; 580 goto out; 581 } 582 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 583 if (err) 584 goto out; 585 586 err = nilfs_store_magic_and_option(sb, sbp, data); 587 if (err) 588 goto failed_sbh; 589 590 err = nilfs_check_feature_compatibility(sb, sbp); 591 if (err) 592 goto failed_sbh; 593 594 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); 595 if (blocksize < NILFS_MIN_BLOCK_SIZE || 596 blocksize > NILFS_MAX_BLOCK_SIZE) { 597 nilfs_msg(sb, KERN_ERR, 598 "couldn't mount because of unsupported filesystem blocksize %d", 599 blocksize); 600 err = -EINVAL; 601 goto failed_sbh; 602 } 603 if (sb->s_blocksize != blocksize) { 604 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 605 606 if (blocksize < hw_blocksize) { 607 nilfs_msg(sb, KERN_ERR, 608 "blocksize %d too small for device (sector-size = %d)", 609 blocksize, hw_blocksize); 610 err = -EINVAL; 611 goto failed_sbh; 612 } 613 nilfs_release_super_block(nilfs); 614 sb_set_blocksize(sb, blocksize); 615 616 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 617 if (err) 618 goto out; 619 /* 620 * Not to failed_sbh; sbh is released automatically 621 * when reloading fails. 622 */ 623 } 624 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 625 nilfs->ns_blocksize = blocksize; 626 627 get_random_bytes(&nilfs->ns_next_generation, 628 sizeof(nilfs->ns_next_generation)); 629 630 err = nilfs_store_disk_layout(nilfs, sbp); 631 if (err) 632 goto failed_sbh; 633 634 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 635 636 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 637 638 err = nilfs_store_log_cursor(nilfs, sbp); 639 if (err) 640 goto failed_sbh; 641 642 err = nilfs_sysfs_create_device_group(sb); 643 if (err) 644 goto failed_sbh; 645 646 set_nilfs_init(nilfs); 647 err = 0; 648 out: 649 up_write(&nilfs->ns_sem); 650 return err; 651 652 failed_sbh: 653 nilfs_release_super_block(nilfs); 654 goto out; 655 } 656 657 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 658 size_t nsegs) 659 { 660 sector_t seg_start, seg_end; 661 sector_t start = 0, nblocks = 0; 662 unsigned int sects_per_block; 663 __u64 *sn; 664 int ret = 0; 665 666 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 667 bdev_logical_block_size(nilfs->ns_bdev); 668 for (sn = segnump; sn < segnump + nsegs; sn++) { 669 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 670 671 if (!nblocks) { 672 start = seg_start; 673 nblocks = seg_end - seg_start + 1; 674 } else if (start + nblocks == seg_start) { 675 nblocks += seg_end - seg_start + 1; 676 } else { 677 ret = blkdev_issue_discard(nilfs->ns_bdev, 678 start * sects_per_block, 679 nblocks * sects_per_block, 680 GFP_NOFS, 0); 681 if (ret < 0) 682 return ret; 683 nblocks = 0; 684 } 685 } 686 if (nblocks) 687 ret = blkdev_issue_discard(nilfs->ns_bdev, 688 start * sects_per_block, 689 nblocks * sects_per_block, 690 GFP_NOFS, 0); 691 return ret; 692 } 693 694 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 695 { 696 unsigned long ncleansegs; 697 698 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 699 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 700 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 701 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 702 return 0; 703 } 704 705 int nilfs_near_disk_full(struct the_nilfs *nilfs) 706 { 707 unsigned long ncleansegs, nincsegs; 708 709 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 710 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 711 nilfs->ns_blocks_per_segment + 1; 712 713 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 714 } 715 716 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 717 { 718 struct rb_node *n; 719 struct nilfs_root *root; 720 721 spin_lock(&nilfs->ns_cptree_lock); 722 n = nilfs->ns_cptree.rb_node; 723 while (n) { 724 root = rb_entry(n, struct nilfs_root, rb_node); 725 726 if (cno < root->cno) { 727 n = n->rb_left; 728 } else if (cno > root->cno) { 729 n = n->rb_right; 730 } else { 731 refcount_inc(&root->count); 732 spin_unlock(&nilfs->ns_cptree_lock); 733 return root; 734 } 735 } 736 spin_unlock(&nilfs->ns_cptree_lock); 737 738 return NULL; 739 } 740 741 struct nilfs_root * 742 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 743 { 744 struct rb_node **p, *parent; 745 struct nilfs_root *root, *new; 746 int err; 747 748 root = nilfs_lookup_root(nilfs, cno); 749 if (root) 750 return root; 751 752 new = kzalloc(sizeof(*root), GFP_KERNEL); 753 if (!new) 754 return NULL; 755 756 spin_lock(&nilfs->ns_cptree_lock); 757 758 p = &nilfs->ns_cptree.rb_node; 759 parent = NULL; 760 761 while (*p) { 762 parent = *p; 763 root = rb_entry(parent, struct nilfs_root, rb_node); 764 765 if (cno < root->cno) { 766 p = &(*p)->rb_left; 767 } else if (cno > root->cno) { 768 p = &(*p)->rb_right; 769 } else { 770 refcount_inc(&root->count); 771 spin_unlock(&nilfs->ns_cptree_lock); 772 kfree(new); 773 return root; 774 } 775 } 776 777 new->cno = cno; 778 new->ifile = NULL; 779 new->nilfs = nilfs; 780 refcount_set(&new->count, 1); 781 atomic64_set(&new->inodes_count, 0); 782 atomic64_set(&new->blocks_count, 0); 783 784 rb_link_node(&new->rb_node, parent, p); 785 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 786 787 spin_unlock(&nilfs->ns_cptree_lock); 788 789 err = nilfs_sysfs_create_snapshot_group(new); 790 if (err) { 791 kfree(new); 792 new = NULL; 793 } 794 795 return new; 796 } 797 798 void nilfs_put_root(struct nilfs_root *root) 799 { 800 if (refcount_dec_and_test(&root->count)) { 801 struct the_nilfs *nilfs = root->nilfs; 802 803 nilfs_sysfs_delete_snapshot_group(root); 804 805 spin_lock(&nilfs->ns_cptree_lock); 806 rb_erase(&root->rb_node, &nilfs->ns_cptree); 807 spin_unlock(&nilfs->ns_cptree_lock); 808 iput(root->ifile); 809 810 kfree(root); 811 } 812 } 813