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 39static int nilfs_valid_sb(struct nilfs_super_block *sbp); 40 41void 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 */ 68struct 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 nilfs->ns_sb_update_freq = NILFS_SB_FREQ; 89 90 return nilfs; 91} 92 93/** 94 * destroy_nilfs - destroy nilfs object 95 * @nilfs: nilfs object to be released 96 */ 97void destroy_nilfs(struct the_nilfs *nilfs) 98{ 99 might_sleep(); 100 if (nilfs_init(nilfs)) { 101 nilfs_sysfs_delete_device_group(nilfs); 102 brelse(nilfs->ns_sbh[0]); 103 brelse(nilfs->ns_sbh[1]); 104 } 105 kfree(nilfs); 106} 107 108static int nilfs_load_super_root(struct the_nilfs *nilfs, 109 struct super_block *sb, sector_t sr_block) 110{ 111 struct buffer_head *bh_sr; 112 struct nilfs_super_root *raw_sr; 113 struct nilfs_super_block **sbp = nilfs->ns_sbp; 114 struct nilfs_inode *rawi; 115 unsigned dat_entry_size, segment_usage_size, checkpoint_size; 116 unsigned inode_size; 117 int err; 118 119 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1); 120 if (unlikely(err)) 121 return err; 122 123 down_read(&nilfs->ns_sem); 124 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size); 125 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size); 126 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size); 127 up_read(&nilfs->ns_sem); 128 129 inode_size = nilfs->ns_inode_size; 130 131 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size); 132 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat); 133 if (err) 134 goto failed; 135 136 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size); 137 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile); 138 if (err) 139 goto failed_dat; 140 141 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size); 142 err = nilfs_sufile_read(sb, segment_usage_size, rawi, 143 &nilfs->ns_sufile); 144 if (err) 145 goto failed_cpfile; 146 147 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 148 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime); 149 150 failed: 151 brelse(bh_sr); 152 return err; 153 154 failed_cpfile: 155 iput(nilfs->ns_cpfile); 156 157 failed_dat: 158 iput(nilfs->ns_dat); 159 goto failed; 160} 161 162static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri) 163{ 164 memset(ri, 0, sizeof(*ri)); 165 INIT_LIST_HEAD(&ri->ri_used_segments); 166} 167 168static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri) 169{ 170 nilfs_dispose_segment_list(&ri->ri_used_segments); 171} 172 173/** 174 * nilfs_store_log_cursor - load log cursor from a super block 175 * @nilfs: nilfs object 176 * @sbp: buffer storing super block to be read 177 * 178 * nilfs_store_log_cursor() reads the last position of the log 179 * containing a super root from a given super block, and initializes 180 * relevant information on the nilfs object preparatory for log 181 * scanning and recovery. 182 */ 183static int nilfs_store_log_cursor(struct the_nilfs *nilfs, 184 struct nilfs_super_block *sbp) 185{ 186 int ret = 0; 187 188 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg); 189 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno); 190 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq); 191 192 nilfs->ns_prev_seq = nilfs->ns_last_seq; 193 nilfs->ns_seg_seq = nilfs->ns_last_seq; 194 nilfs->ns_segnum = 195 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg); 196 nilfs->ns_cno = nilfs->ns_last_cno + 1; 197 if (nilfs->ns_segnum >= nilfs->ns_nsegments) { 198 printk(KERN_ERR "NILFS invalid last segment number.\n"); 199 ret = -EINVAL; 200 } 201 return ret; 202} 203 204/** 205 * load_nilfs - load and recover the nilfs 206 * @nilfs: the_nilfs structure to be released 207 * @sb: super block isntance used to recover past segment 208 * 209 * load_nilfs() searches and load the latest super root, 210 * attaches the last segment, and does recovery if needed. 211 * The caller must call this exclusively for simultaneous mounts. 212 */ 213int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb) 214{ 215 struct nilfs_recovery_info ri; 216 unsigned int s_flags = sb->s_flags; 217 int really_read_only = bdev_read_only(nilfs->ns_bdev); 218 int valid_fs = nilfs_valid_fs(nilfs); 219 int err; 220 221 if (!valid_fs) { 222 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n"); 223 if (s_flags & MS_RDONLY) { 224 printk(KERN_INFO "NILFS: INFO: recovery " 225 "required for readonly filesystem.\n"); 226 printk(KERN_INFO "NILFS: write access will " 227 "be enabled during recovery.\n"); 228 } 229 } 230 231 nilfs_init_recovery_info(&ri); 232 233 err = nilfs_search_super_root(nilfs, &ri); 234 if (unlikely(err)) { 235 struct nilfs_super_block **sbp = nilfs->ns_sbp; 236 int blocksize; 237 238 if (err != -EINVAL) 239 goto scan_error; 240 241 if (!nilfs_valid_sb(sbp[1])) { 242 printk(KERN_WARNING 243 "NILFS warning: unable to fall back to spare" 244 "super block\n"); 245 goto scan_error; 246 } 247 printk(KERN_INFO 248 "NILFS: try rollback from an earlier position\n"); 249 250 /* 251 * restore super block with its spare and reconfigure 252 * relevant states of the nilfs object. 253 */ 254 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize); 255 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed); 256 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 257 258 /* verify consistency between two super blocks */ 259 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size); 260 if (blocksize != nilfs->ns_blocksize) { 261 printk(KERN_WARNING 262 "NILFS warning: blocksize differs between " 263 "two super blocks (%d != %d)\n", 264 blocksize, nilfs->ns_blocksize); 265 goto scan_error; 266 } 267 268 err = nilfs_store_log_cursor(nilfs, sbp[0]); 269 if (err) 270 goto scan_error; 271 272 /* drop clean flag to allow roll-forward and recovery */ 273 nilfs->ns_mount_state &= ~NILFS_VALID_FS; 274 valid_fs = 0; 275 276 err = nilfs_search_super_root(nilfs, &ri); 277 if (err) 278 goto scan_error; 279 } 280 281 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root); 282 if (unlikely(err)) { 283 printk(KERN_ERR "NILFS: error loading super root.\n"); 284 goto failed; 285 } 286 287 if (valid_fs) 288 goto skip_recovery; 289 290 if (s_flags & MS_RDONLY) { 291 __u64 features; 292 293 if (nilfs_test_opt(nilfs, NORECOVERY)) { 294 printk(KERN_INFO "NILFS: norecovery option specified. " 295 "skipping roll-forward recovery\n"); 296 goto skip_recovery; 297 } 298 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) & 299 ~NILFS_FEATURE_COMPAT_RO_SUPP; 300 if (features) { 301 printk(KERN_ERR "NILFS: couldn't proceed with " 302 "recovery because of unsupported optional " 303 "features (%llx)\n", 304 (unsigned long long)features); 305 err = -EROFS; 306 goto failed_unload; 307 } 308 if (really_read_only) { 309 printk(KERN_ERR "NILFS: write access " 310 "unavailable, cannot proceed.\n"); 311 err = -EROFS; 312 goto failed_unload; 313 } 314 sb->s_flags &= ~MS_RDONLY; 315 } else if (nilfs_test_opt(nilfs, NORECOVERY)) { 316 printk(KERN_ERR "NILFS: recovery cancelled because norecovery " 317 "option was specified for a read/write mount\n"); 318 err = -EINVAL; 319 goto failed_unload; 320 } 321 322 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri); 323 if (err) 324 goto failed_unload; 325 326 down_write(&nilfs->ns_sem); 327 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */ 328 err = nilfs_cleanup_super(sb); 329 up_write(&nilfs->ns_sem); 330 331 if (err) { 332 printk(KERN_ERR "NILFS: failed to update super block. " 333 "recovery unfinished.\n"); 334 goto failed_unload; 335 } 336 printk(KERN_INFO "NILFS: recovery complete.\n"); 337 338 skip_recovery: 339 nilfs_clear_recovery_info(&ri); 340 sb->s_flags = s_flags; 341 return 0; 342 343 scan_error: 344 printk(KERN_ERR "NILFS: error searching super root.\n"); 345 goto failed; 346 347 failed_unload: 348 iput(nilfs->ns_cpfile); 349 iput(nilfs->ns_sufile); 350 iput(nilfs->ns_dat); 351 352 failed: 353 nilfs_clear_recovery_info(&ri); 354 sb->s_flags = s_flags; 355 return err; 356} 357 358static unsigned long long nilfs_max_size(unsigned int blkbits) 359{ 360 unsigned int max_bits; 361 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */ 362 363 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */ 364 if (max_bits < 64) 365 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1); 366 return res; 367} 368 369/** 370 * nilfs_nrsvsegs - calculate the number of reserved segments 371 * @nilfs: nilfs object 372 * @nsegs: total number of segments 373 */ 374unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs) 375{ 376 return max_t(unsigned long, NILFS_MIN_NRSVSEGS, 377 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage, 378 100)); 379} 380 381void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs) 382{ 383 nilfs->ns_nsegments = nsegs; 384 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs); 385} 386 387static int nilfs_store_disk_layout(struct the_nilfs *nilfs, 388 struct nilfs_super_block *sbp) 389{ 390 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) { 391 printk(KERN_ERR "NILFS: unsupported revision " 392 "(superblock rev.=%d.%d, current rev.=%d.%d). " 393 "Please check the version of mkfs.nilfs.\n", 394 le32_to_cpu(sbp->s_rev_level), 395 le16_to_cpu(sbp->s_minor_rev_level), 396 NILFS_CURRENT_REV, NILFS_MINOR_REV); 397 return -EINVAL; 398 } 399 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes); 400 if (nilfs->ns_sbsize > BLOCK_SIZE) 401 return -EINVAL; 402 403 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size); 404 if (nilfs->ns_inode_size > nilfs->ns_blocksize) { 405 printk(KERN_ERR "NILFS: too large inode size: %d bytes.\n", 406 nilfs->ns_inode_size); 407 return -EINVAL; 408 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) { 409 printk(KERN_ERR "NILFS: too small inode size: %d bytes.\n", 410 nilfs->ns_inode_size); 411 return -EINVAL; 412 } 413 414 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); 415 416 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); 417 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { 418 printk(KERN_ERR "NILFS: too short segment.\n"); 419 return -EINVAL; 420 } 421 422 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block); 423 nilfs->ns_r_segments_percentage = 424 le32_to_cpu(sbp->s_r_segments_percentage); 425 if (nilfs->ns_r_segments_percentage < 1 || 426 nilfs->ns_r_segments_percentage > 99) { 427 printk(KERN_ERR "NILFS: invalid reserved segments percentage.\n"); 428 return -EINVAL; 429 } 430 431 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments)); 432 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed); 433 return 0; 434} 435 436static int nilfs_valid_sb(struct nilfs_super_block *sbp) 437{ 438 static unsigned char sum[4]; 439 const int sumoff = offsetof(struct nilfs_super_block, s_sum); 440 size_t bytes; 441 u32 crc; 442 443 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC) 444 return 0; 445 bytes = le16_to_cpu(sbp->s_bytes); 446 if (bytes > BLOCK_SIZE) 447 return 0; 448 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp, 449 sumoff); 450 crc = crc32_le(crc, sum, 4); 451 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4, 452 bytes - sumoff - 4); 453 return crc == le32_to_cpu(sbp->s_sum); 454} 455 456static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset) 457{ 458 return offset < ((le64_to_cpu(sbp->s_nsegments) * 459 le32_to_cpu(sbp->s_blocks_per_segment)) << 460 (le32_to_cpu(sbp->s_log_block_size) + 10)); 461} 462 463static void nilfs_release_super_block(struct the_nilfs *nilfs) 464{ 465 int i; 466 467 for (i = 0; i < 2; i++) { 468 if (nilfs->ns_sbp[i]) { 469 brelse(nilfs->ns_sbh[i]); 470 nilfs->ns_sbh[i] = NULL; 471 nilfs->ns_sbp[i] = NULL; 472 } 473 } 474} 475 476void nilfs_fall_back_super_block(struct the_nilfs *nilfs) 477{ 478 brelse(nilfs->ns_sbh[0]); 479 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 480 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 481 nilfs->ns_sbh[1] = NULL; 482 nilfs->ns_sbp[1] = NULL; 483} 484 485void nilfs_swap_super_block(struct the_nilfs *nilfs) 486{ 487 struct buffer_head *tsbh = nilfs->ns_sbh[0]; 488 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0]; 489 490 nilfs->ns_sbh[0] = nilfs->ns_sbh[1]; 491 nilfs->ns_sbp[0] = nilfs->ns_sbp[1]; 492 nilfs->ns_sbh[1] = tsbh; 493 nilfs->ns_sbp[1] = tsbp; 494} 495 496static int nilfs_load_super_block(struct the_nilfs *nilfs, 497 struct super_block *sb, int blocksize, 498 struct nilfs_super_block **sbpp) 499{ 500 struct nilfs_super_block **sbp = nilfs->ns_sbp; 501 struct buffer_head **sbh = nilfs->ns_sbh; 502 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size); 503 int valid[2], swp = 0; 504 505 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize, 506 &sbh[0]); 507 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]); 508 509 if (!sbp[0]) { 510 if (!sbp[1]) { 511 printk(KERN_ERR "NILFS: unable to read superblock\n"); 512 return -EIO; 513 } 514 printk(KERN_WARNING 515 "NILFS warning: unable to read primary superblock " 516 "(blocksize = %d)\n", blocksize); 517 } else if (!sbp[1]) { 518 printk(KERN_WARNING 519 "NILFS warning: unable to read secondary superblock " 520 "(blocksize = %d)\n", blocksize); 521 } 522 523 /* 524 * Compare two super blocks and set 1 in swp if the secondary 525 * super block is valid and newer. Otherwise, set 0 in swp. 526 */ 527 valid[0] = nilfs_valid_sb(sbp[0]); 528 valid[1] = nilfs_valid_sb(sbp[1]); 529 swp = valid[1] && (!valid[0] || 530 le64_to_cpu(sbp[1]->s_last_cno) > 531 le64_to_cpu(sbp[0]->s_last_cno)); 532 533 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) { 534 brelse(sbh[1]); 535 sbh[1] = NULL; 536 sbp[1] = NULL; 537 valid[1] = 0; 538 swp = 0; 539 } 540 if (!valid[swp]) { 541 nilfs_release_super_block(nilfs); 542 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n", 543 sb->s_id); 544 return -EINVAL; 545 } 546 547 if (!valid[!swp]) 548 printk(KERN_WARNING "NILFS warning: broken superblock. " 549 "using spare superblock (blocksize = %d).\n", blocksize); 550 if (swp) 551 nilfs_swap_super_block(nilfs); 552 553 nilfs->ns_sbwcount = 0; 554 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime); 555 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq); 556 *sbpp = sbp[0]; 557 return 0; 558} 559 560/** 561 * init_nilfs - initialize a NILFS instance. 562 * @nilfs: the_nilfs structure 563 * @sb: super block 564 * @data: mount options 565 * 566 * init_nilfs() performs common initialization per block device (e.g. 567 * reading the super block, getting disk layout information, initializing 568 * shared fields in the_nilfs). 569 * 570 * Return Value: On success, 0 is returned. On error, a negative error 571 * code is returned. 572 */ 573int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data) 574{ 575 struct nilfs_super_block *sbp; 576 int blocksize; 577 int err; 578 579 down_write(&nilfs->ns_sem); 580 581 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE); 582 if (!blocksize) { 583 printk(KERN_ERR "NILFS: unable to set blocksize\n"); 584 err = -EINVAL; 585 goto out; 586 } 587 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 588 if (err) 589 goto out; 590 591 err = nilfs_store_magic_and_option(sb, sbp, data); 592 if (err) 593 goto failed_sbh; 594 595 err = nilfs_check_feature_compatibility(sb, sbp); 596 if (err) 597 goto failed_sbh; 598 599 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size); 600 if (blocksize < NILFS_MIN_BLOCK_SIZE || 601 blocksize > NILFS_MAX_BLOCK_SIZE) { 602 printk(KERN_ERR "NILFS: couldn't mount because of unsupported " 603 "filesystem blocksize %d\n", blocksize); 604 err = -EINVAL; 605 goto failed_sbh; 606 } 607 if (sb->s_blocksize != blocksize) { 608 int hw_blocksize = bdev_logical_block_size(sb->s_bdev); 609 610 if (blocksize < hw_blocksize) { 611 printk(KERN_ERR 612 "NILFS: blocksize %d too small for device " 613 "(sector-size = %d).\n", 614 blocksize, hw_blocksize); 615 err = -EINVAL; 616 goto failed_sbh; 617 } 618 nilfs_release_super_block(nilfs); 619 sb_set_blocksize(sb, blocksize); 620 621 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp); 622 if (err) 623 goto out; 624 /* not failed_sbh; sbh is released automatically 625 when reloading fails. */ 626 } 627 nilfs->ns_blocksize_bits = sb->s_blocksize_bits; 628 nilfs->ns_blocksize = blocksize; 629 630 get_random_bytes(&nilfs->ns_next_generation, 631 sizeof(nilfs->ns_next_generation)); 632 633 err = nilfs_store_disk_layout(nilfs, sbp); 634 if (err) 635 goto failed_sbh; 636 637 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits); 638 639 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state); 640 641 err = nilfs_store_log_cursor(nilfs, sbp); 642 if (err) 643 goto failed_sbh; 644 645 err = nilfs_sysfs_create_device_group(sb); 646 if (err) 647 goto failed_sbh; 648 649 set_nilfs_init(nilfs); 650 err = 0; 651 out: 652 up_write(&nilfs->ns_sem); 653 return err; 654 655 failed_sbh: 656 nilfs_release_super_block(nilfs); 657 goto out; 658} 659 660int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump, 661 size_t nsegs) 662{ 663 sector_t seg_start, seg_end; 664 sector_t start = 0, nblocks = 0; 665 unsigned int sects_per_block; 666 __u64 *sn; 667 int ret = 0; 668 669 sects_per_block = (1 << nilfs->ns_blocksize_bits) / 670 bdev_logical_block_size(nilfs->ns_bdev); 671 for (sn = segnump; sn < segnump + nsegs; sn++) { 672 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end); 673 674 if (!nblocks) { 675 start = seg_start; 676 nblocks = seg_end - seg_start + 1; 677 } else if (start + nblocks == seg_start) { 678 nblocks += seg_end - seg_start + 1; 679 } else { 680 ret = blkdev_issue_discard(nilfs->ns_bdev, 681 start * sects_per_block, 682 nblocks * sects_per_block, 683 GFP_NOFS, 0); 684 if (ret < 0) 685 return ret; 686 nblocks = 0; 687 } 688 } 689 if (nblocks) 690 ret = blkdev_issue_discard(nilfs->ns_bdev, 691 start * sects_per_block, 692 nblocks * sects_per_block, 693 GFP_NOFS, 0); 694 return ret; 695} 696 697int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks) 698{ 699 unsigned long ncleansegs; 700 701 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 702 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 703 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem); 704 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment; 705 return 0; 706} 707 708int nilfs_near_disk_full(struct the_nilfs *nilfs) 709{ 710 unsigned long ncleansegs, nincsegs; 711 712 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile); 713 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) / 714 nilfs->ns_blocks_per_segment + 1; 715 716 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs; 717} 718 719struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno) 720{ 721 struct rb_node *n; 722 struct nilfs_root *root; 723 724 spin_lock(&nilfs->ns_cptree_lock); 725 n = nilfs->ns_cptree.rb_node; 726 while (n) { 727 root = rb_entry(n, struct nilfs_root, rb_node); 728 729 if (cno < root->cno) { 730 n = n->rb_left; 731 } else if (cno > root->cno) { 732 n = n->rb_right; 733 } else { 734 atomic_inc(&root->count); 735 spin_unlock(&nilfs->ns_cptree_lock); 736 return root; 737 } 738 } 739 spin_unlock(&nilfs->ns_cptree_lock); 740 741 return NULL; 742} 743 744struct nilfs_root * 745nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno) 746{ 747 struct rb_node **p, *parent; 748 struct nilfs_root *root, *new; 749 int err; 750 751 root = nilfs_lookup_root(nilfs, cno); 752 if (root) 753 return root; 754 755 new = kzalloc(sizeof(*root), GFP_KERNEL); 756 if (!new) 757 return NULL; 758 759 spin_lock(&nilfs->ns_cptree_lock); 760 761 p = &nilfs->ns_cptree.rb_node; 762 parent = NULL; 763 764 while (*p) { 765 parent = *p; 766 root = rb_entry(parent, struct nilfs_root, rb_node); 767 768 if (cno < root->cno) { 769 p = &(*p)->rb_left; 770 } else if (cno > root->cno) { 771 p = &(*p)->rb_right; 772 } else { 773 atomic_inc(&root->count); 774 spin_unlock(&nilfs->ns_cptree_lock); 775 kfree(new); 776 return root; 777 } 778 } 779 780 new->cno = cno; 781 new->ifile = NULL; 782 new->nilfs = nilfs; 783 atomic_set(&new->count, 1); 784 atomic64_set(&new->inodes_count, 0); 785 atomic64_set(&new->blocks_count, 0); 786 787 rb_link_node(&new->rb_node, parent, p); 788 rb_insert_color(&new->rb_node, &nilfs->ns_cptree); 789 790 spin_unlock(&nilfs->ns_cptree_lock); 791 792 err = nilfs_sysfs_create_snapshot_group(new); 793 if (err) { 794 kfree(new); 795 new = NULL; 796 } 797 798 return new; 799} 800 801void nilfs_put_root(struct nilfs_root *root) 802{ 803 if (atomic_dec_and_test(&root->count)) { 804 struct the_nilfs *nilfs = root->nilfs; 805 806 nilfs_sysfs_delete_snapshot_group(root); 807 808 spin_lock(&nilfs->ns_cptree_lock); 809 rb_erase(&root->rb_node, &nilfs->ns_cptree); 810 spin_unlock(&nilfs->ns_cptree_lock); 811 iput(root->ifile); 812 813 kfree(root); 814 } 815} 816