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 INIT_LIST_HEAD(&nilfs->ns_dirty_files); 80 INIT_LIST_HEAD(&nilfs->ns_gc_inodes); 81 spin_lock_init(&nilfs->ns_inode_lock); 82 spin_lock_init(&nilfs->ns_next_gen_lock); 83 spin_lock_init(&nilfs->ns_last_segment_lock); 84 nilfs->ns_cptree = RB_ROOT; 85 spin_lock_init(&nilfs->ns_cptree_lock); 86 init_rwsem(&nilfs->ns_segctor_sem); 87 88 return nilfs; 89 } 90 91 /** 92 * destroy_nilfs - destroy nilfs object 93 * @nilfs: nilfs object to be released 94 */ 95 void destroy_nilfs(struct the_nilfs *nilfs) 96 { 97 might_sleep(); 98 if (nilfs_init(nilfs)) { 99 brelse(nilfs->ns_sbh[0]); 100 brelse(nilfs->ns_sbh[1]); 101 } 102 kfree(nilfs); 103 } 104 105 static int nilfs_load_super_root(struct the_nilfs *nilfs, 106 struct super_block *sb, sector_t sr_block) 107 { 108 struct buffer_head *bh_sr; 109 struct nilfs_super_root *raw_sr; 110 struct nilfs_super_block **sbp = nilfs->ns_sbp; 111 struct nilfs_inode *rawi; 112 unsigned dat_entry_size, segment_usage_size, checkpoint_size; 113 unsigned inode_size; 114 int err; 115 116 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1); 117 if (unlikely(err)) 118 return err; 119 120 down_read(&nilfs->ns_sem); 121 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size); 122 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size); 123 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size); 124 up_read(&nilfs->ns_sem); 125 126 inode_size = nilfs->ns_inode_size; 127 128 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size); 129 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat); 130 if (err) 131 goto failed; 132 133 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size); 134 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile); 135 if (err) 136 goto failed_dat; 137 138 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size); 139 err = nilfs_sufile_read(sb, segment_usage_size, rawi, 140 &nilfs->ns_sufile); 141 if (err) 142 goto failed_cpfile; 143 144 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 145 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime); 146 147 failed: 148 brelse(bh_sr); 149 return err; 150 151 failed_cpfile: 152 iput(nilfs->ns_cpfile); 153 154 failed_dat: 155 iput(nilfs->ns_dat); 156 goto failed; 157 } 158 159 static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri) 160 { 161 memset(ri, 0, sizeof(*ri)); 162 INIT_LIST_HEAD(&ri->ri_used_segments); 163 } 164 165 static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri) 166 { 167 nilfs_dispose_segment_list(&ri->ri_used_segments); 168 } 169 170 /** 171 * nilfs_store_log_cursor - load log cursor from a super block 172 * @nilfs: nilfs object 173 * @sbp: buffer storing super block to be read 174 * 175 * nilfs_store_log_cursor() reads the last position of the log 176 * containing a super root from a given super block, and initializes 177 * relevant information on the nilfs object preparatory for log 178 * scanning and recovery. 179 */ 180 static int nilfs_store_log_cursor(struct the_nilfs *nilfs, 181 struct nilfs_super_block *sbp) 182 { 183 int ret = 0; 184 185 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg); 186 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno); 187 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq); 188 189 nilfs->ns_prev_seq = nilfs->ns_last_seq; 190 nilfs->ns_seg_seq = nilfs->ns_last_seq; 191 nilfs->ns_segnum = 192 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg); 193 nilfs->ns_cno = nilfs->ns_last_cno + 1; 194 if (nilfs->ns_segnum >= nilfs->ns_nsegments) { 195 printk(KERN_ERR "NILFS invalid last segment number.\n"); 196 ret = -EINVAL; 197 } 198 return ret; 199 } 200 201 /** 202 * load_nilfs - load and recover the nilfs 203 * @nilfs: the_nilfs structure to be released 204 * @sb: super block isntance used to recover past segment 205 * 206 * load_nilfs() searches and load the latest super root, 207 * attaches the last segment, and does recovery if needed. 208 * The caller must call this exclusively for simultaneous mounts. 209 */ 210 int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb) 211 { 212 struct nilfs_recovery_info ri; 213 unsigned int s_flags = sb->s_flags; 214 int really_read_only = bdev_read_only(nilfs->ns_bdev); 215 int valid_fs = nilfs_valid_fs(nilfs); 216 int err; 217 218 if (!valid_fs) { 219 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); 220 if (s_flags & MS_RDONLY) { 221 printk(KERN_INFO "NILFS: INFO: recovery " 222 "required for readonly filesystem.\n"); 223 printk(KERN_INFO "NILFS: write access will " 224 "be enabled during recovery.\n"); 225 } 226 } 227 228 nilfs_init_recovery_info(&ri); 229 230 err = nilfs_search_super_root(nilfs, &ri); 231 if (unlikely(err)) { 232 struct nilfs_super_block **sbp = nilfs->ns_sbp; 233 int blocksize; 234 235 if (err != -EINVAL) 236 goto scan_error; 237 238 if (!nilfs_valid_sb(sbp[1])) { 239 printk(KERN_WARNING 240 "NILFS warning: unable to fall back to spare" 241 "super block\n"); 242 goto scan_error; 243 } 244 printk(KERN_INFO 245 "NILFS: try rollback from an earlier position\n"); 246 247 /* 248 * restore super block with its spare and reconfigure 249 * relevant states of the nilfs object. 250 */ 251 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 252 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed); 253 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 254 255 /* verify consistency between two super blocks */ 256 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size); 257 if (blocksize != nilfs->ns_blocksize) { 258 printk(KERN_WARNING 259 "NILFS warning: blocksize differs between " 260 "two super blocks (%d != %d)\n", 261 blocksize, nilfs->ns_blocksize); 262 goto scan_error; 263 } 264 265 err = nilfs_store_log_cursor(nilfs, sbp[0]); 266 if (err) 267 goto scan_error; 268 269 /* drop clean flag to allow roll-forward and recovery */ 270 nilfs->ns_mount_state &= ~NILFS_VALID_FS; 271 valid_fs = 0; 272 273 err = nilfs_search_super_root(nilfs, &ri); 274 if (err) 275 goto scan_error; 276 } 277 278 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root); 279 if (unlikely(err)) { 280 printk(KERN_ERR "NILFS: error loading super root.\n"); 281 goto failed; 282 } 283 284 if (valid_fs) 285 goto skip_recovery; 286 287 if (s_flags & MS_RDONLY) { 288 __u64 features; 289 290 if (nilfs_test_opt(nilfs, NORECOVERY)) { 291 printk(KERN_INFO "NILFS: norecovery option specified. " 292 "skipping roll-forward recovery\n"); 293 goto skip_recovery; 294 } 295 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 296 ~NILFS_FEATURE_COMPAT_RO_SUPP; 297 if (features) { 298 printk(KERN_ERR "NILFS: couldn't proceed with " 299 "recovery because of unsupported optional " 300 "features (%llx)\n", 301 (unsigned long long)features); 302 err = -EROFS; 303 goto failed_unload; 304 } 305 if (really_read_only) { 306 printk(KERN_ERR "NILFS: write access " 307 "unavailable, cannot proceed.\n"); 308 err = -EROFS; 309 goto failed_unload; 310 } 311 sb->s_flags &= ~MS_RDONLY; 312 } else if (nilfs_test_opt(nilfs, NORECOVERY)) { 313 printk(KERN_ERR "NILFS: recovery cancelled because norecovery " 314 "option was specified for a read/write mount\n"); 315 err = -EINVAL; 316 goto failed_unload; 317 } 318 319 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri); 320 if (err) 321 goto failed_unload; 322 323 down_write(&nilfs->ns_sem); 324 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */ 325 err = nilfs_cleanup_super(sb); 326 up_write(&nilfs->ns_sem); 327 328 if (err) { 329 printk(KERN_ERR "NILFS: failed to update super block. " 330 "recovery unfinished.\n"); 331 goto failed_unload; 332 } 333 printk(KERN_INFO "NILFS: recovery complete.\n"); 334 335 skip_recovery: 336 nilfs_clear_recovery_info(&ri); 337 sb->s_flags = s_flags; 338 return 0; 339 340 scan_error: 341 printk(KERN_ERR "NILFS: error searching super root.\n"); 342 goto failed; 343 344 failed_unload: 345 iput(nilfs->ns_cpfile); 346 iput(nilfs->ns_sufile); 347 iput(nilfs->ns_dat); 348 349 failed: 350 nilfs_clear_recovery_info(&ri); 351 sb->s_flags = s_flags; 352 return err; 353 } 354 355 static unsigned long long nilfs_max_size(unsigned int blkbits) 356 { 357 unsigned int max_bits; 358 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ 359 360 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ 361 if (max_bits < 64) 362 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); 363 return res; 364 } 365 366 /** 367 * nilfs_nrsvsegs - calculate the number of reserved segments 368 * @nilfs: nilfs object 369 * @nsegs: total number of segments 370 */ 371 unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs) 372 { 373 return max_t(unsigned long, NILFS_MIN_NRSVSEGS, 374 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage, 375 100)); 376 } 377 378 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs) 379 { 380 nilfs->ns_nsegments = nsegs; 381 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs); 382 } 383 384 static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 385 struct nilfs_super_block *sbp) 386 { 387 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 388 printk(KERN_ERR "NILFS: unsupported revision " 389 "(superblock rev.=%d.%d, current rev.=%d.%d). " 390 "Please check the version of mkfs.nilfs.\n", 391 le32_to_cpu(sbp->s_rev_level), 392 le16_to_cpu(sbp->s_minor_rev_level), 393 NILFS_CURRENT_REV, NILFS_MINOR_REV); 394 return -EINVAL; 395 } 396 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 397 if (nilfs->ns_sbsize > BLOCK_SIZE) 398 return -EINVAL; 399 400 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 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 printk(KERN_ERR "NILFS: too short segment.\n"); 406 return -EINVAL; 407 } 408 409 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); 410 nilfs->ns_r_segments_percentage = 411 le32_to_cpu(sbp->s_r_segments_percentage); 412 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments)); 413 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 414 return 0; 415 } 416 417 static int nilfs_valid_sb(struct nilfs_super_block *sbp) 418 { 419 static unsigned char sum[4]; 420 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 421 size_t bytes; 422 u32 crc; 423 424 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 425 return 0; 426 bytes = le16_to_cpu(sbp->s_bytes); 427 if (bytes > BLOCK_SIZE) 428 return 0; 429 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 430 sumoff); 431 crc = crc32_le(crc, sum, 4); 432 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 433 bytes - sumoff - 4); 434 return crc == le32_to_cpu(sbp->s_sum); 435 } 436 437 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 438 { 439 return offset < ((le64_to_cpu(sbp->s_nsegments) * 440 le32_to_cpu(sbp->s_blocks_per_segment)) << 441 (le32_to_cpu(sbp->s_log_block_size) + 10)); 442 } 443 444 static void nilfs_release_super_block(struct the_nilfs *nilfs) 445 { 446 int i; 447 448 for (i = 0; i < 2; i++) { 449 if (nilfs->ns_sbp[i]) { 450 brelse(nilfs->ns_sbh[i]); 451 nilfs->ns_sbh[i] = NULL; 452 nilfs->ns_sbp[i] = NULL; 453 } 454 } 455 } 456 457 void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 458 { 459 brelse(nilfs->ns_sbh[0]); 460 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 461 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 462 nilfs->ns_sbh[1] = NULL; 463 nilfs->ns_sbp[1] = NULL; 464 } 465 466 void nilfs_swap_super_block(struct the_nilfs *nilfs) 467 { 468 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 469 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 470 471 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 472 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 473 nilfs->ns_sbh[1] = tsbh; 474 nilfs->ns_sbp[1] = tsbp; 475 } 476 477 static int nilfs_load_super_block(struct the_nilfs *nilfs, 478 struct super_block *sb, int blocksize, 479 struct nilfs_super_block **sbpp) 480 { 481 struct nilfs_super_block **sbp = nilfs->ns_sbp; 482 struct buffer_head **sbh = nilfs->ns_sbh; 483 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); 484 int valid[2], swp = 0; 485 486 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 487 &sbh[0]); 488 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 489 490 if (!sbp[0]) { 491 if (!sbp[1]) { 492 printk(KERN_ERR "NILFS: unable to read superblock\n"); 493 return -EIO; 494 } 495 printk(KERN_WARNING 496 "NILFS warning: unable to read primary superblock " 497 "(blocksize = %d)\n", blocksize); 498 } else if (!sbp[1]) { 499 printk(KERN_WARNING 500 "NILFS warning: unable to read secondary superblock " 501 "(blocksize = %d)\n", blocksize); 502 } 503 504 /* 505 * Compare two super blocks and set 1 in swp if the secondary 506 * super block is valid and newer. Otherwise, set 0 in swp. 507 */ 508 valid[0] = nilfs_valid_sb(sbp[0]); 509 valid[1] = nilfs_valid_sb(sbp[1]); 510 swp = valid[1] && (!valid[0] || 511 le64_to_cpu(sbp[1]->s_last_cno) > 512 le64_to_cpu(sbp[0]->s_last_cno)); 513 514 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 515 brelse(sbh[1]); 516 sbh[1] = NULL; 517 sbp[1] = NULL; 518 swp = 0; 519 } 520 if (!valid[swp]) { 521 nilfs_release_super_block(nilfs); 522 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n", 523 sb->s_id); 524 return -EINVAL; 525 } 526 527 if (!valid[!swp]) 528 printk(KERN_WARNING "NILFS warning: broken superblock. " 529 "using spare superblock (blocksize = %d).\n", blocksize); 530 if (swp) 531 nilfs_swap_super_block(nilfs); 532 533 nilfs->ns_sbwcount = 0; 534 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 535 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); 536 *sbpp = sbp[0]; 537 return 0; 538 } 539 540 /** 541 * init_nilfs - initialize a NILFS instance. 542 * @nilfs: the_nilfs structure 543 * @sb: super block 544 * @data: mount options 545 * 546 * init_nilfs() performs common initialization per block device (e.g. 547 * reading the super block, getting disk layout information, initializing 548 * shared fields in the_nilfs). 549 * 550 * Return Value: On success, 0 is returned. On error, a negative error 551 * code is returned. 552 */ 553 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data) 554 { 555 struct nilfs_super_block *sbp; 556 int blocksize; 557 int err; 558 559 down_write(&nilfs->ns_sem); 560 561 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 562 if (!blocksize) { 563 printk(KERN_ERR "NILFS: unable to set blocksize\n"); 564 err = -EINVAL; 565 goto out; 566 } 567 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 568 if (err) 569 goto out; 570 571 err = nilfs_store_magic_and_option(sb, sbp, data); 572 if (err) 573 goto failed_sbh; 574 575 err = nilfs_check_feature_compatibility(sb, sbp); 576 if (err) 577 goto failed_sbh; 578 579 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); 580 if (blocksize < NILFS_MIN_BLOCK_SIZE || 581 blocksize > NILFS_MAX_BLOCK_SIZE) { 582 printk(KERN_ERR "NILFS: couldn't mount because of unsupported " 583 "filesystem blocksize %d\n", blocksize); 584 err = -EINVAL; 585 goto failed_sbh; 586 } 587 if (sb->s_blocksize != blocksize) { 588 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 589 590 if (blocksize < hw_blocksize) { 591 printk(KERN_ERR 592 "NILFS: blocksize %d too small for device " 593 "(sector-size = %d).\n", 594 blocksize, hw_blocksize); 595 err = -EINVAL; 596 goto failed_sbh; 597 } 598 nilfs_release_super_block(nilfs); 599 sb_set_blocksize(sb, blocksize); 600 601 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 602 if (err) 603 goto out; 604 /* not failed_sbh; sbh is released automatically 605 when reloading fails. */ 606 } 607 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 608 nilfs->ns_blocksize = blocksize; 609 610 get_random_bytes(&nilfs->ns_next_generation, 611 sizeof(nilfs->ns_next_generation)); 612 613 err = nilfs_store_disk_layout(nilfs, sbp); 614 if (err) 615 goto failed_sbh; 616 617 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 618 619 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 620 621 err = nilfs_store_log_cursor(nilfs, sbp); 622 if (err) 623 goto failed_sbh; 624 625 set_nilfs_init(nilfs); 626 err = 0; 627 out: 628 up_write(&nilfs->ns_sem); 629 return err; 630 631 failed_sbh: 632 nilfs_release_super_block(nilfs); 633 goto out; 634 } 635 636 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 637 size_t nsegs) 638 { 639 sector_t seg_start, seg_end; 640 sector_t start = 0, nblocks = 0; 641 unsigned int sects_per_block; 642 __u64 *sn; 643 int ret = 0; 644 645 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 646 bdev_logical_block_size(nilfs->ns_bdev); 647 for (sn = segnump; sn < segnump + nsegs; sn++) { 648 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 649 650 if (!nblocks) { 651 start = seg_start; 652 nblocks = seg_end - seg_start + 1; 653 } else if (start + nblocks == seg_start) { 654 nblocks += seg_end - seg_start + 1; 655 } else { 656 ret = blkdev_issue_discard(nilfs->ns_bdev, 657 start * sects_per_block, 658 nblocks * sects_per_block, 659 GFP_NOFS, 0); 660 if (ret < 0) 661 return ret; 662 nblocks = 0; 663 } 664 } 665 if (nblocks) 666 ret = blkdev_issue_discard(nilfs->ns_bdev, 667 start * sects_per_block, 668 nblocks * sects_per_block, 669 GFP_NOFS, 0); 670 return ret; 671 } 672 673 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 674 { 675 unsigned long ncleansegs; 676 677 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 678 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 679 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 680 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 681 return 0; 682 } 683 684 int nilfs_near_disk_full(struct the_nilfs *nilfs) 685 { 686 unsigned long ncleansegs, nincsegs; 687 688 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 689 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 690 nilfs->ns_blocks_per_segment + 1; 691 692 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 693 } 694 695 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 696 { 697 struct rb_node *n; 698 struct nilfs_root *root; 699 700 spin_lock(&nilfs->ns_cptree_lock); 701 n = nilfs->ns_cptree.rb_node; 702 while (n) { 703 root = rb_entry(n, struct nilfs_root, rb_node); 704 705 if (cno < root->cno) { 706 n = n->rb_left; 707 } else if (cno > root->cno) { 708 n = n->rb_right; 709 } else { 710 atomic_inc(&root->count); 711 spin_unlock(&nilfs->ns_cptree_lock); 712 return root; 713 } 714 } 715 spin_unlock(&nilfs->ns_cptree_lock); 716 717 return NULL; 718 } 719 720 struct nilfs_root * 721 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 722 { 723 struct rb_node **p, *parent; 724 struct nilfs_root *root, *new; 725 726 root = nilfs_lookup_root(nilfs, cno); 727 if (root) 728 return root; 729 730 new = kmalloc(sizeof(*root), GFP_KERNEL); 731 if (!new) 732 return NULL; 733 734 spin_lock(&nilfs->ns_cptree_lock); 735 736 p = &nilfs->ns_cptree.rb_node; 737 parent = NULL; 738 739 while (*p) { 740 parent = *p; 741 root = rb_entry(parent, struct nilfs_root, rb_node); 742 743 if (cno < root->cno) { 744 p = &(*p)->rb_left; 745 } else if (cno > root->cno) { 746 p = &(*p)->rb_right; 747 } else { 748 atomic_inc(&root->count); 749 spin_unlock(&nilfs->ns_cptree_lock); 750 kfree(new); 751 return root; 752 } 753 } 754 755 new->cno = cno; 756 new->ifile = NULL; 757 new->nilfs = nilfs; 758 atomic_set(&new->count, 1); 759 atomic_set(&new->inodes_count, 0); 760 atomic_set(&new->blocks_count, 0); 761 762 rb_link_node(&new->rb_node, parent, p); 763 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 764 765 spin_unlock(&nilfs->ns_cptree_lock); 766 767 return new; 768 } 769 770 void nilfs_put_root(struct nilfs_root *root) 771 { 772 if (atomic_dec_and_test(&root->count)) { 773 struct the_nilfs *nilfs = root->nilfs; 774 775 spin_lock(&nilfs->ns_cptree_lock); 776 rb_erase(&root->rb_node, &nilfs->ns_cptree); 777 spin_unlock(&nilfs->ns_cptree_lock); 778 if (root->ifile) 779 iput(root->ifile); 780 781 kfree(root); 782 } 783 } 784