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 static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 367 struct nilfs_super_block *sbp) 368 { 369 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 370 printk(KERN_ERR "NILFS: unsupported revision " 371 "(superblock rev.=%d.%d, current rev.=%d.%d). " 372 "Please check the version of mkfs.nilfs.\n", 373 le32_to_cpu(sbp->s_rev_level), 374 le16_to_cpu(sbp->s_minor_rev_level), 375 NILFS_CURRENT_REV, NILFS_MINOR_REV); 376 return -EINVAL; 377 } 378 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 379 if (nilfs->ns_sbsize > BLOCK_SIZE) 380 return -EINVAL; 381 382 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 383 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); 384 385 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); 386 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { 387 printk(KERN_ERR "NILFS: too short segment.\n"); 388 return -EINVAL; 389 } 390 391 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); 392 nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments); 393 nilfs->ns_r_segments_percentage = 394 le32_to_cpu(sbp->s_r_segments_percentage); 395 nilfs->ns_nrsvsegs = 396 max_t(unsigned long, NILFS_MIN_NRSVSEGS, 397 DIV_ROUND_UP(nilfs->ns_nsegments * 398 nilfs->ns_r_segments_percentage, 100)); 399 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 400 return 0; 401 } 402 403 static int nilfs_valid_sb(struct nilfs_super_block *sbp) 404 { 405 static unsigned char sum[4]; 406 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 407 size_t bytes; 408 u32 crc; 409 410 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 411 return 0; 412 bytes = le16_to_cpu(sbp->s_bytes); 413 if (bytes > BLOCK_SIZE) 414 return 0; 415 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 416 sumoff); 417 crc = crc32_le(crc, sum, 4); 418 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 419 bytes - sumoff - 4); 420 return crc == le32_to_cpu(sbp->s_sum); 421 } 422 423 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 424 { 425 return offset < ((le64_to_cpu(sbp->s_nsegments) * 426 le32_to_cpu(sbp->s_blocks_per_segment)) << 427 (le32_to_cpu(sbp->s_log_block_size) + 10)); 428 } 429 430 static void nilfs_release_super_block(struct the_nilfs *nilfs) 431 { 432 int i; 433 434 for (i = 0; i < 2; i++) { 435 if (nilfs->ns_sbp[i]) { 436 brelse(nilfs->ns_sbh[i]); 437 nilfs->ns_sbh[i] = NULL; 438 nilfs->ns_sbp[i] = NULL; 439 } 440 } 441 } 442 443 void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 444 { 445 brelse(nilfs->ns_sbh[0]); 446 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 447 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 448 nilfs->ns_sbh[1] = NULL; 449 nilfs->ns_sbp[1] = NULL; 450 } 451 452 void nilfs_swap_super_block(struct the_nilfs *nilfs) 453 { 454 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 455 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 456 457 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 458 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 459 nilfs->ns_sbh[1] = tsbh; 460 nilfs->ns_sbp[1] = tsbp; 461 } 462 463 static int nilfs_load_super_block(struct the_nilfs *nilfs, 464 struct super_block *sb, int blocksize, 465 struct nilfs_super_block **sbpp) 466 { 467 struct nilfs_super_block **sbp = nilfs->ns_sbp; 468 struct buffer_head **sbh = nilfs->ns_sbh; 469 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); 470 int valid[2], swp = 0; 471 472 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 473 &sbh[0]); 474 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 475 476 if (!sbp[0]) { 477 if (!sbp[1]) { 478 printk(KERN_ERR "NILFS: unable to read superblock\n"); 479 return -EIO; 480 } 481 printk(KERN_WARNING 482 "NILFS warning: unable to read primary superblock " 483 "(blocksize = %d)\n", blocksize); 484 } else if (!sbp[1]) { 485 printk(KERN_WARNING 486 "NILFS warning: unable to read secondary superblock " 487 "(blocksize = %d)\n", blocksize); 488 } 489 490 /* 491 * Compare two super blocks and set 1 in swp if the secondary 492 * super block is valid and newer. Otherwise, set 0 in swp. 493 */ 494 valid[0] = nilfs_valid_sb(sbp[0]); 495 valid[1] = nilfs_valid_sb(sbp[1]); 496 swp = valid[1] && (!valid[0] || 497 le64_to_cpu(sbp[1]->s_last_cno) > 498 le64_to_cpu(sbp[0]->s_last_cno)); 499 500 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 501 brelse(sbh[1]); 502 sbh[1] = NULL; 503 sbp[1] = NULL; 504 swp = 0; 505 } 506 if (!valid[swp]) { 507 nilfs_release_super_block(nilfs); 508 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n", 509 sb->s_id); 510 return -EINVAL; 511 } 512 513 if (!valid[!swp]) 514 printk(KERN_WARNING "NILFS warning: broken superblock. " 515 "using spare superblock (blocksize = %d).\n", blocksize); 516 if (swp) 517 nilfs_swap_super_block(nilfs); 518 519 nilfs->ns_sbwcount = 0; 520 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 521 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); 522 *sbpp = sbp[0]; 523 return 0; 524 } 525 526 /** 527 * init_nilfs - initialize a NILFS instance. 528 * @nilfs: the_nilfs structure 529 * @sb: super block 530 * @data: mount options 531 * 532 * init_nilfs() performs common initialization per block device (e.g. 533 * reading the super block, getting disk layout information, initializing 534 * shared fields in the_nilfs). 535 * 536 * Return Value: On success, 0 is returned. On error, a negative error 537 * code is returned. 538 */ 539 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data) 540 { 541 struct nilfs_super_block *sbp; 542 int blocksize; 543 int err; 544 545 down_write(&nilfs->ns_sem); 546 547 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 548 if (!blocksize) { 549 printk(KERN_ERR "NILFS: unable to set blocksize\n"); 550 err = -EINVAL; 551 goto out; 552 } 553 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 554 if (err) 555 goto out; 556 557 err = nilfs_store_magic_and_option(sb, sbp, data); 558 if (err) 559 goto failed_sbh; 560 561 err = nilfs_check_feature_compatibility(sb, sbp); 562 if (err) 563 goto failed_sbh; 564 565 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); 566 if (blocksize < NILFS_MIN_BLOCK_SIZE || 567 blocksize > NILFS_MAX_BLOCK_SIZE) { 568 printk(KERN_ERR "NILFS: couldn't mount because of unsupported " 569 "filesystem blocksize %d\n", blocksize); 570 err = -EINVAL; 571 goto failed_sbh; 572 } 573 if (sb->s_blocksize != blocksize) { 574 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 575 576 if (blocksize < hw_blocksize) { 577 printk(KERN_ERR 578 "NILFS: blocksize %d too small for device " 579 "(sector-size = %d).\n", 580 blocksize, hw_blocksize); 581 err = -EINVAL; 582 goto failed_sbh; 583 } 584 nilfs_release_super_block(nilfs); 585 sb_set_blocksize(sb, blocksize); 586 587 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 588 if (err) 589 goto out; 590 /* not failed_sbh; sbh is released automatically 591 when reloading fails. */ 592 } 593 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 594 nilfs->ns_blocksize = blocksize; 595 596 get_random_bytes(&nilfs->ns_next_generation, 597 sizeof(nilfs->ns_next_generation)); 598 599 err = nilfs_store_disk_layout(nilfs, sbp); 600 if (err) 601 goto failed_sbh; 602 603 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 604 605 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 606 607 err = nilfs_store_log_cursor(nilfs, sbp); 608 if (err) 609 goto failed_sbh; 610 611 set_nilfs_init(nilfs); 612 err = 0; 613 out: 614 up_write(&nilfs->ns_sem); 615 return err; 616 617 failed_sbh: 618 nilfs_release_super_block(nilfs); 619 goto out; 620 } 621 622 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 623 size_t nsegs) 624 { 625 sector_t seg_start, seg_end; 626 sector_t start = 0, nblocks = 0; 627 unsigned int sects_per_block; 628 __u64 *sn; 629 int ret = 0; 630 631 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 632 bdev_logical_block_size(nilfs->ns_bdev); 633 for (sn = segnump; sn < segnump + nsegs; sn++) { 634 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 635 636 if (!nblocks) { 637 start = seg_start; 638 nblocks = seg_end - seg_start + 1; 639 } else if (start + nblocks == seg_start) { 640 nblocks += seg_end - seg_start + 1; 641 } else { 642 ret = blkdev_issue_discard(nilfs->ns_bdev, 643 start * sects_per_block, 644 nblocks * sects_per_block, 645 GFP_NOFS, 0); 646 if (ret < 0) 647 return ret; 648 nblocks = 0; 649 } 650 } 651 if (nblocks) 652 ret = blkdev_issue_discard(nilfs->ns_bdev, 653 start * sects_per_block, 654 nblocks * sects_per_block, 655 GFP_NOFS, 0); 656 return ret; 657 } 658 659 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 660 { 661 unsigned long ncleansegs; 662 663 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 664 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 665 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 666 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 667 return 0; 668 } 669 670 int nilfs_near_disk_full(struct the_nilfs *nilfs) 671 { 672 unsigned long ncleansegs, nincsegs; 673 674 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 675 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 676 nilfs->ns_blocks_per_segment + 1; 677 678 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 679 } 680 681 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 682 { 683 struct rb_node *n; 684 struct nilfs_root *root; 685 686 spin_lock(&nilfs->ns_cptree_lock); 687 n = nilfs->ns_cptree.rb_node; 688 while (n) { 689 root = rb_entry(n, struct nilfs_root, rb_node); 690 691 if (cno < root->cno) { 692 n = n->rb_left; 693 } else if (cno > root->cno) { 694 n = n->rb_right; 695 } else { 696 atomic_inc(&root->count); 697 spin_unlock(&nilfs->ns_cptree_lock); 698 return root; 699 } 700 } 701 spin_unlock(&nilfs->ns_cptree_lock); 702 703 return NULL; 704 } 705 706 struct nilfs_root * 707 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 708 { 709 struct rb_node **p, *parent; 710 struct nilfs_root *root, *new; 711 712 root = nilfs_lookup_root(nilfs, cno); 713 if (root) 714 return root; 715 716 new = kmalloc(sizeof(*root), GFP_KERNEL); 717 if (!new) 718 return NULL; 719 720 spin_lock(&nilfs->ns_cptree_lock); 721 722 p = &nilfs->ns_cptree.rb_node; 723 parent = NULL; 724 725 while (*p) { 726 parent = *p; 727 root = rb_entry(parent, struct nilfs_root, rb_node); 728 729 if (cno < root->cno) { 730 p = &(*p)->rb_left; 731 } else if (cno > root->cno) { 732 p = &(*p)->rb_right; 733 } else { 734 atomic_inc(&root->count); 735 spin_unlock(&nilfs->ns_cptree_lock); 736 kfree(new); 737 return root; 738 } 739 } 740 741 new->cno = cno; 742 new->ifile = NULL; 743 new->nilfs = nilfs; 744 atomic_set(&new->count, 1); 745 atomic_set(&new->inodes_count, 0); 746 atomic_set(&new->blocks_count, 0); 747 748 rb_link_node(&new->rb_node, parent, p); 749 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 750 751 spin_unlock(&nilfs->ns_cptree_lock); 752 753 return new; 754 } 755 756 void nilfs_put_root(struct nilfs_root *root) 757 { 758 if (atomic_dec_and_test(&root->count)) { 759 struct the_nilfs *nilfs = root->nilfs; 760 761 spin_lock(&nilfs->ns_cptree_lock); 762 rb_erase(&root->rb_node, &nilfs->ns_cptree); 763 spin_unlock(&nilfs->ns_cptree_lock); 764 if (root->ifile) 765 iput(root->ifile); 766 767 kfree(root); 768 } 769 } 770