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/crc32.h> 29 #include "nilfs.h" 30 #include "segment.h" 31 #include "alloc.h" 32 #include "cpfile.h" 33 #include "sufile.h" 34 #include "dat.h" 35 #include "segbuf.h" 36 37 38 static int nilfs_valid_sb(struct nilfs_super_block *sbp); 39 40 void nilfs_set_last_segment(struct the_nilfs *nilfs, 41 sector_t start_blocknr, u64 seq, __u64 cno) 42 { 43 spin_lock(&nilfs->ns_last_segment_lock); 44 nilfs->ns_last_pseg = start_blocknr; 45 nilfs->ns_last_seq = seq; 46 nilfs->ns_last_cno = cno; 47 48 if (!nilfs_sb_dirty(nilfs)) { 49 if (nilfs->ns_prev_seq == nilfs->ns_last_seq) 50 goto stay_cursor; 51 52 set_nilfs_sb_dirty(nilfs); 53 } 54 nilfs->ns_prev_seq = nilfs->ns_last_seq; 55 56 stay_cursor: 57 spin_unlock(&nilfs->ns_last_segment_lock); 58 } 59 60 /** 61 * alloc_nilfs - allocate a nilfs object 62 * @bdev: block device to which the_nilfs is related 63 * 64 * Return Value: On success, pointer to the_nilfs is returned. 65 * On error, NULL is returned. 66 */ 67 struct the_nilfs *alloc_nilfs(struct block_device *bdev) 68 { 69 struct the_nilfs *nilfs; 70 71 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL); 72 if (!nilfs) 73 return NULL; 74 75 nilfs->ns_bdev = bdev; 76 atomic_set(&nilfs->ns_ndirtyblks, 0); 77 init_rwsem(&nilfs->ns_sem); 78 INIT_LIST_HEAD(&nilfs->ns_gc_inodes); 79 spin_lock_init(&nilfs->ns_last_segment_lock); 80 nilfs->ns_cptree = RB_ROOT; 81 spin_lock_init(&nilfs->ns_cptree_lock); 82 init_rwsem(&nilfs->ns_segctor_sem); 83 84 return nilfs; 85 } 86 87 /** 88 * destroy_nilfs - destroy nilfs object 89 * @nilfs: nilfs object to be released 90 */ 91 void destroy_nilfs(struct the_nilfs *nilfs) 92 { 93 might_sleep(); 94 if (nilfs_init(nilfs)) { 95 brelse(nilfs->ns_sbh[0]); 96 brelse(nilfs->ns_sbh[1]); 97 } 98 kfree(nilfs); 99 } 100 101 static int nilfs_load_super_root(struct the_nilfs *nilfs, 102 struct super_block *sb, sector_t sr_block) 103 { 104 struct buffer_head *bh_sr; 105 struct nilfs_super_root *raw_sr; 106 struct nilfs_super_block **sbp = nilfs->ns_sbp; 107 struct nilfs_inode *rawi; 108 unsigned dat_entry_size, segment_usage_size, checkpoint_size; 109 unsigned inode_size; 110 int err; 111 112 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1); 113 if (unlikely(err)) 114 return err; 115 116 down_read(&nilfs->ns_sem); 117 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size); 118 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size); 119 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size); 120 up_read(&nilfs->ns_sem); 121 122 inode_size = nilfs->ns_inode_size; 123 124 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size); 125 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat); 126 if (err) 127 goto failed; 128 129 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size); 130 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile); 131 if (err) 132 goto failed_dat; 133 134 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size); 135 err = nilfs_sufile_read(sb, segment_usage_size, rawi, 136 &nilfs->ns_sufile); 137 if (err) 138 goto failed_cpfile; 139 140 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 141 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime); 142 143 failed: 144 brelse(bh_sr); 145 return err; 146 147 failed_cpfile: 148 iput(nilfs->ns_cpfile); 149 150 failed_dat: 151 iput(nilfs->ns_dat); 152 goto failed; 153 } 154 155 static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri) 156 { 157 memset(ri, 0, sizeof(*ri)); 158 INIT_LIST_HEAD(&ri->ri_used_segments); 159 } 160 161 static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri) 162 { 163 nilfs_dispose_segment_list(&ri->ri_used_segments); 164 } 165 166 /** 167 * nilfs_store_log_cursor - load log cursor from a super block 168 * @nilfs: nilfs object 169 * @sbp: buffer storing super block to be read 170 * 171 * nilfs_store_log_cursor() reads the last position of the log 172 * containing a super root from a given super block, and initializes 173 * relevant information on the nilfs object preparatory for log 174 * scanning and recovery. 175 */ 176 static int nilfs_store_log_cursor(struct the_nilfs *nilfs, 177 struct nilfs_super_block *sbp) 178 { 179 int ret = 0; 180 181 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg); 182 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno); 183 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq); 184 185 nilfs->ns_prev_seq = nilfs->ns_last_seq; 186 nilfs->ns_seg_seq = nilfs->ns_last_seq; 187 nilfs->ns_segnum = 188 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg); 189 nilfs->ns_cno = nilfs->ns_last_cno + 1; 190 if (nilfs->ns_segnum >= nilfs->ns_nsegments) { 191 printk(KERN_ERR "NILFS invalid last segment number.\n"); 192 ret = -EINVAL; 193 } 194 return ret; 195 } 196 197 /** 198 * load_nilfs - load and recover the nilfs 199 * @nilfs: the_nilfs structure to be released 200 * @sbi: nilfs_sb_info used to recover past segment 201 * 202 * load_nilfs() searches and load the latest super root, 203 * attaches the last segment, and does recovery if needed. 204 * The caller must call this exclusively for simultaneous mounts. 205 */ 206 int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi) 207 { 208 struct nilfs_recovery_info ri; 209 unsigned int s_flags = sbi->s_super->s_flags; 210 int really_read_only = bdev_read_only(nilfs->ns_bdev); 211 int valid_fs = nilfs_valid_fs(nilfs); 212 int err; 213 214 if (!valid_fs) { 215 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); 216 if (s_flags & MS_RDONLY) { 217 printk(KERN_INFO "NILFS: INFO: recovery " 218 "required for readonly filesystem.\n"); 219 printk(KERN_INFO "NILFS: write access will " 220 "be enabled during recovery.\n"); 221 } 222 } 223 224 nilfs_init_recovery_info(&ri); 225 226 err = nilfs_search_super_root(nilfs, &ri); 227 if (unlikely(err)) { 228 struct nilfs_super_block **sbp = nilfs->ns_sbp; 229 int blocksize; 230 231 if (err != -EINVAL) 232 goto scan_error; 233 234 if (!nilfs_valid_sb(sbp[1])) { 235 printk(KERN_WARNING 236 "NILFS warning: unable to fall back to spare" 237 "super block\n"); 238 goto scan_error; 239 } 240 printk(KERN_INFO 241 "NILFS: try rollback from an earlier position\n"); 242 243 /* 244 * restore super block with its spare and reconfigure 245 * relevant states of the nilfs object. 246 */ 247 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 248 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed); 249 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 250 251 /* verify consistency between two super blocks */ 252 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size); 253 if (blocksize != nilfs->ns_blocksize) { 254 printk(KERN_WARNING 255 "NILFS warning: blocksize differs between " 256 "two super blocks (%d != %d)\n", 257 blocksize, nilfs->ns_blocksize); 258 goto scan_error; 259 } 260 261 err = nilfs_store_log_cursor(nilfs, sbp[0]); 262 if (err) 263 goto scan_error; 264 265 /* drop clean flag to allow roll-forward and recovery */ 266 nilfs->ns_mount_state &= ~NILFS_VALID_FS; 267 valid_fs = 0; 268 269 err = nilfs_search_super_root(nilfs, &ri); 270 if (err) 271 goto scan_error; 272 } 273 274 err = nilfs_load_super_root(nilfs, sbi->s_super, ri.ri_super_root); 275 if (unlikely(err)) { 276 printk(KERN_ERR "NILFS: error loading super root.\n"); 277 goto failed; 278 } 279 280 if (valid_fs) 281 goto skip_recovery; 282 283 if (s_flags & MS_RDONLY) { 284 __u64 features; 285 286 if (nilfs_test_opt(sbi, NORECOVERY)) { 287 printk(KERN_INFO "NILFS: norecovery option specified. " 288 "skipping roll-forward recovery\n"); 289 goto skip_recovery; 290 } 291 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 292 ~NILFS_FEATURE_COMPAT_RO_SUPP; 293 if (features) { 294 printk(KERN_ERR "NILFS: couldn't proceed with " 295 "recovery because of unsupported optional " 296 "features (%llx)\n", 297 (unsigned long long)features); 298 err = -EROFS; 299 goto failed_unload; 300 } 301 if (really_read_only) { 302 printk(KERN_ERR "NILFS: write access " 303 "unavailable, cannot proceed.\n"); 304 err = -EROFS; 305 goto failed_unload; 306 } 307 sbi->s_super->s_flags &= ~MS_RDONLY; 308 } else if (nilfs_test_opt(sbi, NORECOVERY)) { 309 printk(KERN_ERR "NILFS: recovery cancelled because norecovery " 310 "option was specified for a read/write mount\n"); 311 err = -EINVAL; 312 goto failed_unload; 313 } 314 315 err = nilfs_salvage_orphan_logs(nilfs, sbi, &ri); 316 if (err) 317 goto failed_unload; 318 319 down_write(&nilfs->ns_sem); 320 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */ 321 err = nilfs_cleanup_super(sbi); 322 up_write(&nilfs->ns_sem); 323 324 if (err) { 325 printk(KERN_ERR "NILFS: failed to update super block. " 326 "recovery unfinished.\n"); 327 goto failed_unload; 328 } 329 printk(KERN_INFO "NILFS: recovery complete.\n"); 330 331 skip_recovery: 332 nilfs_clear_recovery_info(&ri); 333 sbi->s_super->s_flags = s_flags; 334 return 0; 335 336 scan_error: 337 printk(KERN_ERR "NILFS: error searching super root.\n"); 338 goto failed; 339 340 failed_unload: 341 iput(nilfs->ns_cpfile); 342 iput(nilfs->ns_sufile); 343 iput(nilfs->ns_dat); 344 345 failed: 346 nilfs_clear_recovery_info(&ri); 347 sbi->s_super->s_flags = s_flags; 348 return err; 349 } 350 351 static unsigned long long nilfs_max_size(unsigned int blkbits) 352 { 353 unsigned int max_bits; 354 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ 355 356 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ 357 if (max_bits < 64) 358 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); 359 return res; 360 } 361 362 static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 363 struct nilfs_super_block *sbp) 364 { 365 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 366 printk(KERN_ERR "NILFS: unsupported revision " 367 "(superblock rev.=%d.%d, current rev.=%d.%d). " 368 "Please check the version of mkfs.nilfs.\n", 369 le32_to_cpu(sbp->s_rev_level), 370 le16_to_cpu(sbp->s_minor_rev_level), 371 NILFS_CURRENT_REV, NILFS_MINOR_REV); 372 return -EINVAL; 373 } 374 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 375 if (nilfs->ns_sbsize > BLOCK_SIZE) 376 return -EINVAL; 377 378 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 379 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); 380 381 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); 382 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { 383 printk(KERN_ERR "NILFS: too short segment.\n"); 384 return -EINVAL; 385 } 386 387 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); 388 nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments); 389 nilfs->ns_r_segments_percentage = 390 le32_to_cpu(sbp->s_r_segments_percentage); 391 nilfs->ns_nrsvsegs = 392 max_t(unsigned long, NILFS_MIN_NRSVSEGS, 393 DIV_ROUND_UP(nilfs->ns_nsegments * 394 nilfs->ns_r_segments_percentage, 100)); 395 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 396 return 0; 397 } 398 399 static int nilfs_valid_sb(struct nilfs_super_block *sbp) 400 { 401 static unsigned char sum[4]; 402 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 403 size_t bytes; 404 u32 crc; 405 406 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 407 return 0; 408 bytes = le16_to_cpu(sbp->s_bytes); 409 if (bytes > BLOCK_SIZE) 410 return 0; 411 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 412 sumoff); 413 crc = crc32_le(crc, sum, 4); 414 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 415 bytes - sumoff - 4); 416 return crc == le32_to_cpu(sbp->s_sum); 417 } 418 419 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 420 { 421 return offset < ((le64_to_cpu(sbp->s_nsegments) * 422 le32_to_cpu(sbp->s_blocks_per_segment)) << 423 (le32_to_cpu(sbp->s_log_block_size) + 10)); 424 } 425 426 static void nilfs_release_super_block(struct the_nilfs *nilfs) 427 { 428 int i; 429 430 for (i = 0; i < 2; i++) { 431 if (nilfs->ns_sbp[i]) { 432 brelse(nilfs->ns_sbh[i]); 433 nilfs->ns_sbh[i] = NULL; 434 nilfs->ns_sbp[i] = NULL; 435 } 436 } 437 } 438 439 void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 440 { 441 brelse(nilfs->ns_sbh[0]); 442 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 443 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 444 nilfs->ns_sbh[1] = NULL; 445 nilfs->ns_sbp[1] = NULL; 446 } 447 448 void nilfs_swap_super_block(struct the_nilfs *nilfs) 449 { 450 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 451 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 452 453 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 454 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 455 nilfs->ns_sbh[1] = tsbh; 456 nilfs->ns_sbp[1] = tsbp; 457 } 458 459 static int nilfs_load_super_block(struct the_nilfs *nilfs, 460 struct super_block *sb, int blocksize, 461 struct nilfs_super_block **sbpp) 462 { 463 struct nilfs_super_block **sbp = nilfs->ns_sbp; 464 struct buffer_head **sbh = nilfs->ns_sbh; 465 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); 466 int valid[2], swp = 0; 467 468 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 469 &sbh[0]); 470 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 471 472 if (!sbp[0]) { 473 if (!sbp[1]) { 474 printk(KERN_ERR "NILFS: unable to read superblock\n"); 475 return -EIO; 476 } 477 printk(KERN_WARNING 478 "NILFS warning: unable to read primary superblock\n"); 479 } else if (!sbp[1]) 480 printk(KERN_WARNING 481 "NILFS warning: unable to read secondary superblock\n"); 482 483 /* 484 * Compare two super blocks and set 1 in swp if the secondary 485 * super block is valid and newer. Otherwise, set 0 in swp. 486 */ 487 valid[0] = nilfs_valid_sb(sbp[0]); 488 valid[1] = nilfs_valid_sb(sbp[1]); 489 swp = valid[1] && (!valid[0] || 490 le64_to_cpu(sbp[1]->s_last_cno) > 491 le64_to_cpu(sbp[0]->s_last_cno)); 492 493 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 494 brelse(sbh[1]); 495 sbh[1] = NULL; 496 sbp[1] = NULL; 497 swp = 0; 498 } 499 if (!valid[swp]) { 500 nilfs_release_super_block(nilfs); 501 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n", 502 sb->s_id); 503 return -EINVAL; 504 } 505 506 if (!valid[!swp]) 507 printk(KERN_WARNING "NILFS warning: broken superblock. " 508 "using spare superblock.\n"); 509 if (swp) 510 nilfs_swap_super_block(nilfs); 511 512 nilfs->ns_sbwcount = 0; 513 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 514 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); 515 *sbpp = sbp[0]; 516 return 0; 517 } 518 519 /** 520 * init_nilfs - initialize a NILFS instance. 521 * @nilfs: the_nilfs structure 522 * @sbi: nilfs_sb_info 523 * @sb: super block 524 * @data: mount options 525 * 526 * init_nilfs() performs common initialization per block device (e.g. 527 * reading the super block, getting disk layout information, initializing 528 * shared fields in the_nilfs). 529 * 530 * Return Value: On success, 0 is returned. On error, a negative error 531 * code is returned. 532 */ 533 int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data) 534 { 535 struct super_block *sb = sbi->s_super; 536 struct nilfs_super_block *sbp; 537 int blocksize; 538 int err; 539 540 down_write(&nilfs->ns_sem); 541 542 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 543 if (!blocksize) { 544 printk(KERN_ERR "NILFS: unable to set blocksize\n"); 545 err = -EINVAL; 546 goto out; 547 } 548 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 549 if (err) 550 goto out; 551 552 err = nilfs_store_magic_and_option(sb, sbp, data); 553 if (err) 554 goto failed_sbh; 555 556 err = nilfs_check_feature_compatibility(sb, sbp); 557 if (err) 558 goto failed_sbh; 559 560 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); 561 if (blocksize < NILFS_MIN_BLOCK_SIZE || 562 blocksize > NILFS_MAX_BLOCK_SIZE) { 563 printk(KERN_ERR "NILFS: couldn't mount because of unsupported " 564 "filesystem blocksize %d\n", blocksize); 565 err = -EINVAL; 566 goto failed_sbh; 567 } 568 if (sb->s_blocksize != blocksize) { 569 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 570 571 if (blocksize < hw_blocksize) { 572 printk(KERN_ERR 573 "NILFS: blocksize %d too small for device " 574 "(sector-size = %d).\n", 575 blocksize, hw_blocksize); 576 err = -EINVAL; 577 goto failed_sbh; 578 } 579 nilfs_release_super_block(nilfs); 580 sb_set_blocksize(sb, blocksize); 581 582 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 583 if (err) 584 goto out; 585 /* not failed_sbh; sbh is released automatically 586 when reloading fails. */ 587 } 588 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 589 nilfs->ns_blocksize = blocksize; 590 591 err = nilfs_store_disk_layout(nilfs, sbp); 592 if (err) 593 goto failed_sbh; 594 595 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 596 597 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 598 599 err = nilfs_store_log_cursor(nilfs, sbp); 600 if (err) 601 goto failed_sbh; 602 603 set_nilfs_init(nilfs); 604 err = 0; 605 out: 606 up_write(&nilfs->ns_sem); 607 return err; 608 609 failed_sbh: 610 nilfs_release_super_block(nilfs); 611 goto out; 612 } 613 614 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 615 size_t nsegs) 616 { 617 sector_t seg_start, seg_end; 618 sector_t start = 0, nblocks = 0; 619 unsigned int sects_per_block; 620 __u64 *sn; 621 int ret = 0; 622 623 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 624 bdev_logical_block_size(nilfs->ns_bdev); 625 for (sn = segnump; sn < segnump + nsegs; sn++) { 626 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 627 628 if (!nblocks) { 629 start = seg_start; 630 nblocks = seg_end - seg_start + 1; 631 } else if (start + nblocks == seg_start) { 632 nblocks += seg_end - seg_start + 1; 633 } else { 634 ret = blkdev_issue_discard(nilfs->ns_bdev, 635 start * sects_per_block, 636 nblocks * sects_per_block, 637 GFP_NOFS, 0); 638 if (ret < 0) 639 return ret; 640 nblocks = 0; 641 } 642 } 643 if (nblocks) 644 ret = blkdev_issue_discard(nilfs->ns_bdev, 645 start * sects_per_block, 646 nblocks * sects_per_block, 647 GFP_NOFS, 0); 648 return ret; 649 } 650 651 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 652 { 653 unsigned long ncleansegs; 654 655 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 656 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 657 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 658 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 659 return 0; 660 } 661 662 int nilfs_near_disk_full(struct the_nilfs *nilfs) 663 { 664 unsigned long ncleansegs, nincsegs; 665 666 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 667 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 668 nilfs->ns_blocks_per_segment + 1; 669 670 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 671 } 672 673 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 674 { 675 struct rb_node *n; 676 struct nilfs_root *root; 677 678 spin_lock(&nilfs->ns_cptree_lock); 679 n = nilfs->ns_cptree.rb_node; 680 while (n) { 681 root = rb_entry(n, struct nilfs_root, rb_node); 682 683 if (cno < root->cno) { 684 n = n->rb_left; 685 } else if (cno > root->cno) { 686 n = n->rb_right; 687 } else { 688 atomic_inc(&root->count); 689 spin_unlock(&nilfs->ns_cptree_lock); 690 return root; 691 } 692 } 693 spin_unlock(&nilfs->ns_cptree_lock); 694 695 return NULL; 696 } 697 698 struct nilfs_root * 699 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 700 { 701 struct rb_node **p, *parent; 702 struct nilfs_root *root, *new; 703 704 root = nilfs_lookup_root(nilfs, cno); 705 if (root) 706 return root; 707 708 new = kmalloc(sizeof(*root), GFP_KERNEL); 709 if (!new) 710 return NULL; 711 712 spin_lock(&nilfs->ns_cptree_lock); 713 714 p = &nilfs->ns_cptree.rb_node; 715 parent = NULL; 716 717 while (*p) { 718 parent = *p; 719 root = rb_entry(parent, struct nilfs_root, rb_node); 720 721 if (cno < root->cno) { 722 p = &(*p)->rb_left; 723 } else if (cno > root->cno) { 724 p = &(*p)->rb_right; 725 } else { 726 atomic_inc(&root->count); 727 spin_unlock(&nilfs->ns_cptree_lock); 728 kfree(new); 729 return root; 730 } 731 } 732 733 new->cno = cno; 734 new->ifile = NULL; 735 new->nilfs = nilfs; 736 atomic_set(&new->count, 1); 737 atomic_set(&new->inodes_count, 0); 738 atomic_set(&new->blocks_count, 0); 739 740 rb_link_node(&new->rb_node, parent, p); 741 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 742 743 spin_unlock(&nilfs->ns_cptree_lock); 744 745 return new; 746 } 747 748 void nilfs_put_root(struct nilfs_root *root) 749 { 750 if (atomic_dec_and_test(&root->count)) { 751 struct the_nilfs *nilfs = root->nilfs; 752 753 spin_lock(&nilfs->ns_cptree_lock); 754 rb_erase(&root->rb_node, &nilfs->ns_cptree); 755 spin_unlock(&nilfs->ns_cptree_lock); 756 if (root->ifile) 757 iput(root->ifile); 758 759 kfree(root); 760 } 761 } 762