1 /* 2 * the_nilfs.c - the_nilfs shared structure. 3 * 4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 * 20 * Written by Ryusuke Konishi <ryusuke@osrg.net> 21 * 22 */ 23 24 #include <linux/buffer_head.h> 25 #include <linux/slab.h> 26 #include <linux/blkdev.h> 27 #include <linux/backing-dev.h> 28 #include <linux/random.h> 29 #include <linux/crc32.h> 30 #include "nilfs.h" 31 #include "segment.h" 32 #include "alloc.h" 33 #include "cpfile.h" 34 #include "sufile.h" 35 #include "dat.h" 36 #include "segbuf.h" 37 38 39 static int nilfs_valid_sb(struct nilfs_super_block *sbp); 40 41 void nilfs_set_last_segment(struct the_nilfs *nilfs, 42 sector_t start_blocknr, u64 seq, __u64 cno) 43 { 44 spin_lock(&nilfs->ns_last_segment_lock); 45 nilfs->ns_last_pseg = start_blocknr; 46 nilfs->ns_last_seq = seq; 47 nilfs->ns_last_cno = cno; 48 49 if (!nilfs_sb_dirty(nilfs)) { 50 if (nilfs->ns_prev_seq == nilfs->ns_last_seq) 51 goto stay_cursor; 52 53 set_nilfs_sb_dirty(nilfs); 54 } 55 nilfs->ns_prev_seq = nilfs->ns_last_seq; 56 57 stay_cursor: 58 spin_unlock(&nilfs->ns_last_segment_lock); 59 } 60 61 /** 62 * alloc_nilfs - allocate a nilfs object 63 * @bdev: block device to which the_nilfs is related 64 * 65 * Return Value: On success, pointer to the_nilfs is returned. 66 * On error, NULL is returned. 67 */ 68 struct the_nilfs *alloc_nilfs(struct block_device *bdev) 69 { 70 struct the_nilfs *nilfs; 71 72 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL); 73 if (!nilfs) 74 return NULL; 75 76 nilfs->ns_bdev = bdev; 77 atomic_set(&nilfs->ns_ndirtyblks, 0); 78 init_rwsem(&nilfs->ns_sem); 79 mutex_init(&nilfs->ns_snapshot_mount_mutex); 80 INIT_LIST_HEAD(&nilfs->ns_dirty_files); 81 INIT_LIST_HEAD(&nilfs->ns_gc_inodes); 82 spin_lock_init(&nilfs->ns_inode_lock); 83 spin_lock_init(&nilfs->ns_next_gen_lock); 84 spin_lock_init(&nilfs->ns_last_segment_lock); 85 nilfs->ns_cptree = RB_ROOT; 86 spin_lock_init(&nilfs->ns_cptree_lock); 87 init_rwsem(&nilfs->ns_segctor_sem); 88 89 return nilfs; 90 } 91 92 /** 93 * destroy_nilfs - destroy nilfs object 94 * @nilfs: nilfs object to be released 95 */ 96 void destroy_nilfs(struct the_nilfs *nilfs) 97 { 98 might_sleep(); 99 if (nilfs_init(nilfs)) { 100 brelse(nilfs->ns_sbh[0]); 101 brelse(nilfs->ns_sbh[1]); 102 } 103 kfree(nilfs); 104 } 105 106 static int nilfs_load_super_root(struct the_nilfs *nilfs, 107 struct super_block *sb, sector_t sr_block) 108 { 109 struct buffer_head *bh_sr; 110 struct nilfs_super_root *raw_sr; 111 struct nilfs_super_block **sbp = nilfs->ns_sbp; 112 struct nilfs_inode *rawi; 113 unsigned dat_entry_size, segment_usage_size, checkpoint_size; 114 unsigned inode_size; 115 int err; 116 117 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1); 118 if (unlikely(err)) 119 return err; 120 121 down_read(&nilfs->ns_sem); 122 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size); 123 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size); 124 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size); 125 up_read(&nilfs->ns_sem); 126 127 inode_size = nilfs->ns_inode_size; 128 129 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size); 130 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat); 131 if (err) 132 goto failed; 133 134 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size); 135 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile); 136 if (err) 137 goto failed_dat; 138 139 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size); 140 err = nilfs_sufile_read(sb, segment_usage_size, rawi, 141 &nilfs->ns_sufile); 142 if (err) 143 goto failed_cpfile; 144 145 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 146 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime); 147 148 failed: 149 brelse(bh_sr); 150 return err; 151 152 failed_cpfile: 153 iput(nilfs->ns_cpfile); 154 155 failed_dat: 156 iput(nilfs->ns_dat); 157 goto failed; 158 } 159 160 static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri) 161 { 162 memset(ri, 0, sizeof(*ri)); 163 INIT_LIST_HEAD(&ri->ri_used_segments); 164 } 165 166 static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri) 167 { 168 nilfs_dispose_segment_list(&ri->ri_used_segments); 169 } 170 171 /** 172 * nilfs_store_log_cursor - load log cursor from a super block 173 * @nilfs: nilfs object 174 * @sbp: buffer storing super block to be read 175 * 176 * nilfs_store_log_cursor() reads the last position of the log 177 * containing a super root from a given super block, and initializes 178 * relevant information on the nilfs object preparatory for log 179 * scanning and recovery. 180 */ 181 static int nilfs_store_log_cursor(struct the_nilfs *nilfs, 182 struct nilfs_super_block *sbp) 183 { 184 int ret = 0; 185 186 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg); 187 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno); 188 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq); 189 190 nilfs->ns_prev_seq = nilfs->ns_last_seq; 191 nilfs->ns_seg_seq = nilfs->ns_last_seq; 192 nilfs->ns_segnum = 193 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg); 194 nilfs->ns_cno = nilfs->ns_last_cno + 1; 195 if (nilfs->ns_segnum >= nilfs->ns_nsegments) { 196 printk(KERN_ERR "NILFS invalid last segment number.\n"); 197 ret = -EINVAL; 198 } 199 return ret; 200 } 201 202 /** 203 * load_nilfs - load and recover the nilfs 204 * @nilfs: the_nilfs structure to be released 205 * @sb: super block isntance used to recover past segment 206 * 207 * load_nilfs() searches and load the latest super root, 208 * attaches the last segment, and does recovery if needed. 209 * The caller must call this exclusively for simultaneous mounts. 210 */ 211 int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb) 212 { 213 struct nilfs_recovery_info ri; 214 unsigned int s_flags = sb->s_flags; 215 int really_read_only = bdev_read_only(nilfs->ns_bdev); 216 int valid_fs = nilfs_valid_fs(nilfs); 217 int err; 218 219 if (!valid_fs) { 220 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); 221 if (s_flags & MS_RDONLY) { 222 printk(KERN_INFO "NILFS: INFO: recovery " 223 "required for readonly filesystem.\n"); 224 printk(KERN_INFO "NILFS: write access will " 225 "be enabled during recovery.\n"); 226 } 227 } 228 229 nilfs_init_recovery_info(&ri); 230 231 err = nilfs_search_super_root(nilfs, &ri); 232 if (unlikely(err)) { 233 struct nilfs_super_block **sbp = nilfs->ns_sbp; 234 int blocksize; 235 236 if (err != -EINVAL) 237 goto scan_error; 238 239 if (!nilfs_valid_sb(sbp[1])) { 240 printk(KERN_WARNING 241 "NILFS warning: unable to fall back to spare" 242 "super block\n"); 243 goto scan_error; 244 } 245 printk(KERN_INFO 246 "NILFS: try rollback from an earlier position\n"); 247 248 /* 249 * restore super block with its spare and reconfigure 250 * relevant states of the nilfs object. 251 */ 252 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 253 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed); 254 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 255 256 /* verify consistency between two super blocks */ 257 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size); 258 if (blocksize != nilfs->ns_blocksize) { 259 printk(KERN_WARNING 260 "NILFS warning: blocksize differs between " 261 "two super blocks (%d != %d)\n", 262 blocksize, nilfs->ns_blocksize); 263 goto scan_error; 264 } 265 266 err = nilfs_store_log_cursor(nilfs, sbp[0]); 267 if (err) 268 goto scan_error; 269 270 /* drop clean flag to allow roll-forward and recovery */ 271 nilfs->ns_mount_state &= ~NILFS_VALID_FS; 272 valid_fs = 0; 273 274 err = nilfs_search_super_root(nilfs, &ri); 275 if (err) 276 goto scan_error; 277 } 278 279 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root); 280 if (unlikely(err)) { 281 printk(KERN_ERR "NILFS: error loading super root.\n"); 282 goto failed; 283 } 284 285 if (valid_fs) 286 goto skip_recovery; 287 288 if (s_flags & MS_RDONLY) { 289 __u64 features; 290 291 if (nilfs_test_opt(nilfs, NORECOVERY)) { 292 printk(KERN_INFO "NILFS: norecovery option specified. " 293 "skipping roll-forward recovery\n"); 294 goto skip_recovery; 295 } 296 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 297 ~NILFS_FEATURE_COMPAT_RO_SUPP; 298 if (features) { 299 printk(KERN_ERR "NILFS: couldn't proceed with " 300 "recovery because of unsupported optional " 301 "features (%llx)\n", 302 (unsigned long long)features); 303 err = -EROFS; 304 goto failed_unload; 305 } 306 if (really_read_only) { 307 printk(KERN_ERR "NILFS: write access " 308 "unavailable, cannot proceed.\n"); 309 err = -EROFS; 310 goto failed_unload; 311 } 312 sb->s_flags &= ~MS_RDONLY; 313 } else if (nilfs_test_opt(nilfs, NORECOVERY)) { 314 printk(KERN_ERR "NILFS: recovery cancelled because norecovery " 315 "option was specified for a read/write mount\n"); 316 err = -EINVAL; 317 goto failed_unload; 318 } 319 320 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri); 321 if (err) 322 goto failed_unload; 323 324 down_write(&nilfs->ns_sem); 325 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */ 326 err = nilfs_cleanup_super(sb); 327 up_write(&nilfs->ns_sem); 328 329 if (err) { 330 printk(KERN_ERR "NILFS: failed to update super block. " 331 "recovery unfinished.\n"); 332 goto failed_unload; 333 } 334 printk(KERN_INFO "NILFS: recovery complete.\n"); 335 336 skip_recovery: 337 nilfs_clear_recovery_info(&ri); 338 sb->s_flags = s_flags; 339 return 0; 340 341 scan_error: 342 printk(KERN_ERR "NILFS: error searching super root.\n"); 343 goto failed; 344 345 failed_unload: 346 iput(nilfs->ns_cpfile); 347 iput(nilfs->ns_sufile); 348 iput(nilfs->ns_dat); 349 350 failed: 351 nilfs_clear_recovery_info(&ri); 352 sb->s_flags = s_flags; 353 return err; 354 } 355 356 static unsigned long long nilfs_max_size(unsigned int blkbits) 357 { 358 unsigned int max_bits; 359 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ 360 361 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ 362 if (max_bits < 64) 363 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); 364 return res; 365 } 366 367 /** 368 * nilfs_nrsvsegs - calculate the number of reserved segments 369 * @nilfs: nilfs object 370 * @nsegs: total number of segments 371 */ 372 unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs) 373 { 374 return max_t(unsigned long, NILFS_MIN_NRSVSEGS, 375 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage, 376 100)); 377 } 378 379 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs) 380 { 381 nilfs->ns_nsegments = nsegs; 382 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs); 383 } 384 385 static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 386 struct nilfs_super_block *sbp) 387 { 388 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 389 printk(KERN_ERR "NILFS: unsupported revision " 390 "(superblock rev.=%d.%d, current rev.=%d.%d). " 391 "Please check the version of mkfs.nilfs.\n", 392 le32_to_cpu(sbp->s_rev_level), 393 le16_to_cpu(sbp->s_minor_rev_level), 394 NILFS_CURRENT_REV, NILFS_MINOR_REV); 395 return -EINVAL; 396 } 397 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 398 if (nilfs->ns_sbsize > BLOCK_SIZE) 399 return -EINVAL; 400 401 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 402 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); 403 404 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); 405 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { 406 printk(KERN_ERR "NILFS: too short segment.\n"); 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 printk(KERN_ERR "NILFS: invalid reserved segments percentage.\n"); 416 return -EINVAL; 417 } 418 419 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments)); 420 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 421 return 0; 422 } 423 424 static int nilfs_valid_sb(struct nilfs_super_block *sbp) 425 { 426 static unsigned char sum[4]; 427 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 428 size_t bytes; 429 u32 crc; 430 431 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 432 return 0; 433 bytes = le16_to_cpu(sbp->s_bytes); 434 if (bytes > BLOCK_SIZE) 435 return 0; 436 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 437 sumoff); 438 crc = crc32_le(crc, sum, 4); 439 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 440 bytes - sumoff - 4); 441 return crc == le32_to_cpu(sbp->s_sum); 442 } 443 444 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 445 { 446 return offset < ((le64_to_cpu(sbp->s_nsegments) * 447 le32_to_cpu(sbp->s_blocks_per_segment)) << 448 (le32_to_cpu(sbp->s_log_block_size) + 10)); 449 } 450 451 static void nilfs_release_super_block(struct the_nilfs *nilfs) 452 { 453 int i; 454 455 for (i = 0; i < 2; i++) { 456 if (nilfs->ns_sbp[i]) { 457 brelse(nilfs->ns_sbh[i]); 458 nilfs->ns_sbh[i] = NULL; 459 nilfs->ns_sbp[i] = NULL; 460 } 461 } 462 } 463 464 void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 465 { 466 brelse(nilfs->ns_sbh[0]); 467 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 468 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 469 nilfs->ns_sbh[1] = NULL; 470 nilfs->ns_sbp[1] = NULL; 471 } 472 473 void nilfs_swap_super_block(struct the_nilfs *nilfs) 474 { 475 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 476 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 477 478 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 479 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 480 nilfs->ns_sbh[1] = tsbh; 481 nilfs->ns_sbp[1] = tsbp; 482 } 483 484 static int nilfs_load_super_block(struct the_nilfs *nilfs, 485 struct super_block *sb, int blocksize, 486 struct nilfs_super_block **sbpp) 487 { 488 struct nilfs_super_block **sbp = nilfs->ns_sbp; 489 struct buffer_head **sbh = nilfs->ns_sbh; 490 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); 491 int valid[2], swp = 0; 492 493 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 494 &sbh[0]); 495 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 496 497 if (!sbp[0]) { 498 if (!sbp[1]) { 499 printk(KERN_ERR "NILFS: unable to read superblock\n"); 500 return -EIO; 501 } 502 printk(KERN_WARNING 503 "NILFS warning: unable to read primary superblock " 504 "(blocksize = %d)\n", blocksize); 505 } else if (!sbp[1]) { 506 printk(KERN_WARNING 507 "NILFS warning: unable to read secondary superblock " 508 "(blocksize = %d)\n", blocksize); 509 } 510 511 /* 512 * Compare two super blocks and set 1 in swp if the secondary 513 * super block is valid and newer. Otherwise, set 0 in swp. 514 */ 515 valid[0] = nilfs_valid_sb(sbp[0]); 516 valid[1] = nilfs_valid_sb(sbp[1]); 517 swp = valid[1] && (!valid[0] || 518 le64_to_cpu(sbp[1]->s_last_cno) > 519 le64_to_cpu(sbp[0]->s_last_cno)); 520 521 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 522 brelse(sbh[1]); 523 sbh[1] = NULL; 524 sbp[1] = NULL; 525 valid[1] = 0; 526 swp = 0; 527 } 528 if (!valid[swp]) { 529 nilfs_release_super_block(nilfs); 530 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n", 531 sb->s_id); 532 return -EINVAL; 533 } 534 535 if (!valid[!swp]) 536 printk(KERN_WARNING "NILFS warning: broken superblock. " 537 "using spare superblock (blocksize = %d).\n", blocksize); 538 if (swp) 539 nilfs_swap_super_block(nilfs); 540 541 nilfs->ns_sbwcount = 0; 542 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 543 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); 544 *sbpp = sbp[0]; 545 return 0; 546 } 547 548 /** 549 * init_nilfs - initialize a NILFS instance. 550 * @nilfs: the_nilfs structure 551 * @sb: super block 552 * @data: mount options 553 * 554 * init_nilfs() performs common initialization per block device (e.g. 555 * reading the super block, getting disk layout information, initializing 556 * shared fields in the_nilfs). 557 * 558 * Return Value: On success, 0 is returned. On error, a negative error 559 * code is returned. 560 */ 561 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data) 562 { 563 struct nilfs_super_block *sbp; 564 int blocksize; 565 int err; 566 567 down_write(&nilfs->ns_sem); 568 569 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 570 if (!blocksize) { 571 printk(KERN_ERR "NILFS: unable to set blocksize\n"); 572 err = -EINVAL; 573 goto out; 574 } 575 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 576 if (err) 577 goto out; 578 579 err = nilfs_store_magic_and_option(sb, sbp, data); 580 if (err) 581 goto failed_sbh; 582 583 err = nilfs_check_feature_compatibility(sb, sbp); 584 if (err) 585 goto failed_sbh; 586 587 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); 588 if (blocksize < NILFS_MIN_BLOCK_SIZE || 589 blocksize > NILFS_MAX_BLOCK_SIZE) { 590 printk(KERN_ERR "NILFS: couldn't mount because of unsupported " 591 "filesystem blocksize %d\n", blocksize); 592 err = -EINVAL; 593 goto failed_sbh; 594 } 595 if (sb->s_blocksize != blocksize) { 596 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 597 598 if (blocksize < hw_blocksize) { 599 printk(KERN_ERR 600 "NILFS: blocksize %d too small for device " 601 "(sector-size = %d).\n", 602 blocksize, hw_blocksize); 603 err = -EINVAL; 604 goto failed_sbh; 605 } 606 nilfs_release_super_block(nilfs); 607 sb_set_blocksize(sb, blocksize); 608 609 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 610 if (err) 611 goto out; 612 /* not failed_sbh; sbh is released automatically 613 when reloading fails. */ 614 } 615 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 616 nilfs->ns_blocksize = blocksize; 617 618 get_random_bytes(&nilfs->ns_next_generation, 619 sizeof(nilfs->ns_next_generation)); 620 621 err = nilfs_store_disk_layout(nilfs, sbp); 622 if (err) 623 goto failed_sbh; 624 625 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 626 627 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 628 629 err = nilfs_store_log_cursor(nilfs, sbp); 630 if (err) 631 goto failed_sbh; 632 633 set_nilfs_init(nilfs); 634 err = 0; 635 out: 636 up_write(&nilfs->ns_sem); 637 return err; 638 639 failed_sbh: 640 nilfs_release_super_block(nilfs); 641 goto out; 642 } 643 644 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 645 size_t nsegs) 646 { 647 sector_t seg_start, seg_end; 648 sector_t start = 0, nblocks = 0; 649 unsigned int sects_per_block; 650 __u64 *sn; 651 int ret = 0; 652 653 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 654 bdev_logical_block_size(nilfs->ns_bdev); 655 for (sn = segnump; sn < segnump + nsegs; sn++) { 656 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 657 658 if (!nblocks) { 659 start = seg_start; 660 nblocks = seg_end - seg_start + 1; 661 } else if (start + nblocks == seg_start) { 662 nblocks += seg_end - seg_start + 1; 663 } else { 664 ret = blkdev_issue_discard(nilfs->ns_bdev, 665 start * sects_per_block, 666 nblocks * sects_per_block, 667 GFP_NOFS, 0); 668 if (ret < 0) 669 return ret; 670 nblocks = 0; 671 } 672 } 673 if (nblocks) 674 ret = blkdev_issue_discard(nilfs->ns_bdev, 675 start * sects_per_block, 676 nblocks * sects_per_block, 677 GFP_NOFS, 0); 678 return ret; 679 } 680 681 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 682 { 683 unsigned long ncleansegs; 684 685 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 686 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 687 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 688 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 689 return 0; 690 } 691 692 int nilfs_near_disk_full(struct the_nilfs *nilfs) 693 { 694 unsigned long ncleansegs, nincsegs; 695 696 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 697 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 698 nilfs->ns_blocks_per_segment + 1; 699 700 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 701 } 702 703 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 704 { 705 struct rb_node *n; 706 struct nilfs_root *root; 707 708 spin_lock(&nilfs->ns_cptree_lock); 709 n = nilfs->ns_cptree.rb_node; 710 while (n) { 711 root = rb_entry(n, struct nilfs_root, rb_node); 712 713 if (cno < root->cno) { 714 n = n->rb_left; 715 } else if (cno > root->cno) { 716 n = n->rb_right; 717 } else { 718 atomic_inc(&root->count); 719 spin_unlock(&nilfs->ns_cptree_lock); 720 return root; 721 } 722 } 723 spin_unlock(&nilfs->ns_cptree_lock); 724 725 return NULL; 726 } 727 728 struct nilfs_root * 729 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 730 { 731 struct rb_node **p, *parent; 732 struct nilfs_root *root, *new; 733 734 root = nilfs_lookup_root(nilfs, cno); 735 if (root) 736 return root; 737 738 new = kmalloc(sizeof(*root), GFP_KERNEL); 739 if (!new) 740 return NULL; 741 742 spin_lock(&nilfs->ns_cptree_lock); 743 744 p = &nilfs->ns_cptree.rb_node; 745 parent = NULL; 746 747 while (*p) { 748 parent = *p; 749 root = rb_entry(parent, struct nilfs_root, rb_node); 750 751 if (cno < root->cno) { 752 p = &(*p)->rb_left; 753 } else if (cno > root->cno) { 754 p = &(*p)->rb_right; 755 } else { 756 atomic_inc(&root->count); 757 spin_unlock(&nilfs->ns_cptree_lock); 758 kfree(new); 759 return root; 760 } 761 } 762 763 new->cno = cno; 764 new->ifile = NULL; 765 new->nilfs = nilfs; 766 atomic_set(&new->count, 1); 767 atomic64_set(&new->inodes_count, 0); 768 atomic64_set(&new->blocks_count, 0); 769 770 rb_link_node(&new->rb_node, parent, p); 771 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 772 773 spin_unlock(&nilfs->ns_cptree_lock); 774 775 return new; 776 } 777 778 void nilfs_put_root(struct nilfs_root *root) 779 { 780 if (atomic_dec_and_test(&root->count)) { 781 struct the_nilfs *nilfs = root->nilfs; 782 783 spin_lock(&nilfs->ns_cptree_lock); 784 rb_erase(&root->rb_node, &nilfs->ns_cptree); 785 spin_unlock(&nilfs->ns_cptree_lock); 786 if (root->ifile) 787 iput(root->ifile); 788 789 kfree(root); 790 } 791 } 792