1 /* 2 * segment.c - NILFS segment constructor. 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/pagemap.h> 25 #include <linux/buffer_head.h> 26 #include <linux/writeback.h> 27 #include <linux/bio.h> 28 #include <linux/completion.h> 29 #include <linux/blkdev.h> 30 #include <linux/backing-dev.h> 31 #include <linux/freezer.h> 32 #include <linux/kthread.h> 33 #include <linux/crc32.h> 34 #include <linux/pagevec.h> 35 #include <linux/slab.h> 36 #include "nilfs.h" 37 #include "btnode.h" 38 #include "page.h" 39 #include "segment.h" 40 #include "sufile.h" 41 #include "cpfile.h" 42 #include "ifile.h" 43 #include "segbuf.h" 44 45 46 /* 47 * Segment constructor 48 */ 49 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */ 50 51 #define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments 52 appended in collection retry loop */ 53 54 /* Construction mode */ 55 enum { 56 SC_LSEG_SR = 1, /* Make a logical segment having a super root */ 57 SC_LSEG_DSYNC, /* Flush data blocks of a given file and make 58 a logical segment without a super root */ 59 SC_FLUSH_FILE, /* Flush data files, leads to segment writes without 60 creating a checkpoint */ 61 SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without 62 a checkpoint */ 63 }; 64 65 /* Stage numbers of dirty block collection */ 66 enum { 67 NILFS_ST_INIT = 0, 68 NILFS_ST_GC, /* Collecting dirty blocks for GC */ 69 NILFS_ST_FILE, 70 NILFS_ST_IFILE, 71 NILFS_ST_CPFILE, 72 NILFS_ST_SUFILE, 73 NILFS_ST_DAT, 74 NILFS_ST_SR, /* Super root */ 75 NILFS_ST_DSYNC, /* Data sync blocks */ 76 NILFS_ST_DONE, 77 }; 78 79 /* State flags of collection */ 80 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */ 81 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */ 82 #define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */ 83 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED) 84 85 /* Operations depending on the construction mode and file type */ 86 struct nilfs_sc_operations { 87 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *, 88 struct inode *); 89 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *, 90 struct inode *); 91 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *, 92 struct inode *); 93 void (*write_data_binfo)(struct nilfs_sc_info *, 94 struct nilfs_segsum_pointer *, 95 union nilfs_binfo *); 96 void (*write_node_binfo)(struct nilfs_sc_info *, 97 struct nilfs_segsum_pointer *, 98 union nilfs_binfo *); 99 }; 100 101 /* 102 * Other definitions 103 */ 104 static void nilfs_segctor_start_timer(struct nilfs_sc_info *); 105 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int); 106 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *); 107 static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int); 108 109 #define nilfs_cnt32_gt(a, b) \ 110 (typecheck(__u32, a) && typecheck(__u32, b) && \ 111 ((__s32)(b) - (__s32)(a) < 0)) 112 #define nilfs_cnt32_ge(a, b) \ 113 (typecheck(__u32, a) && typecheck(__u32, b) && \ 114 ((__s32)(a) - (__s32)(b) >= 0)) 115 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a) 116 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a) 117 118 static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti) 119 { 120 struct nilfs_transaction_info *cur_ti = current->journal_info; 121 void *save = NULL; 122 123 if (cur_ti) { 124 if (cur_ti->ti_magic == NILFS_TI_MAGIC) 125 return ++cur_ti->ti_count; 126 else { 127 /* 128 * If journal_info field is occupied by other FS, 129 * it is saved and will be restored on 130 * nilfs_transaction_commit(). 131 */ 132 printk(KERN_WARNING 133 "NILFS warning: journal info from a different " 134 "FS\n"); 135 save = current->journal_info; 136 } 137 } 138 if (!ti) { 139 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS); 140 if (!ti) 141 return -ENOMEM; 142 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC; 143 } else { 144 ti->ti_flags = 0; 145 } 146 ti->ti_count = 0; 147 ti->ti_save = save; 148 ti->ti_magic = NILFS_TI_MAGIC; 149 current->journal_info = ti; 150 return 0; 151 } 152 153 /** 154 * nilfs_transaction_begin - start indivisible file operations. 155 * @sb: super block 156 * @ti: nilfs_transaction_info 157 * @vacancy_check: flags for vacancy rate checks 158 * 159 * nilfs_transaction_begin() acquires a reader/writer semaphore, called 160 * the segment semaphore, to make a segment construction and write tasks 161 * exclusive. The function is used with nilfs_transaction_commit() in pairs. 162 * The region enclosed by these two functions can be nested. To avoid a 163 * deadlock, the semaphore is only acquired or released in the outermost call. 164 * 165 * This function allocates a nilfs_transaction_info struct to keep context 166 * information on it. It is initialized and hooked onto the current task in 167 * the outermost call. If a pre-allocated struct is given to @ti, it is used 168 * instead; otherwise a new struct is assigned from a slab. 169 * 170 * When @vacancy_check flag is set, this function will check the amount of 171 * free space, and will wait for the GC to reclaim disk space if low capacity. 172 * 173 * Return Value: On success, 0 is returned. On error, one of the following 174 * negative error code is returned. 175 * 176 * %-ENOMEM - Insufficient memory available. 177 * 178 * %-ENOSPC - No space left on device 179 */ 180 int nilfs_transaction_begin(struct super_block *sb, 181 struct nilfs_transaction_info *ti, 182 int vacancy_check) 183 { 184 struct the_nilfs *nilfs; 185 int ret = nilfs_prepare_segment_lock(ti); 186 187 if (unlikely(ret < 0)) 188 return ret; 189 if (ret > 0) 190 return 0; 191 192 vfs_check_frozen(sb, SB_FREEZE_WRITE); 193 194 nilfs = sb->s_fs_info; 195 down_read(&nilfs->ns_segctor_sem); 196 if (vacancy_check && nilfs_near_disk_full(nilfs)) { 197 up_read(&nilfs->ns_segctor_sem); 198 ret = -ENOSPC; 199 goto failed; 200 } 201 return 0; 202 203 failed: 204 ti = current->journal_info; 205 current->journal_info = ti->ti_save; 206 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 207 kmem_cache_free(nilfs_transaction_cachep, ti); 208 return ret; 209 } 210 211 /** 212 * nilfs_transaction_commit - commit indivisible file operations. 213 * @sb: super block 214 * 215 * nilfs_transaction_commit() releases the read semaphore which is 216 * acquired by nilfs_transaction_begin(). This is only performed 217 * in outermost call of this function. If a commit flag is set, 218 * nilfs_transaction_commit() sets a timer to start the segment 219 * constructor. If a sync flag is set, it starts construction 220 * directly. 221 */ 222 int nilfs_transaction_commit(struct super_block *sb) 223 { 224 struct nilfs_transaction_info *ti = current->journal_info; 225 struct the_nilfs *nilfs = sb->s_fs_info; 226 int err = 0; 227 228 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 229 ti->ti_flags |= NILFS_TI_COMMIT; 230 if (ti->ti_count > 0) { 231 ti->ti_count--; 232 return 0; 233 } 234 if (nilfs->ns_writer) { 235 struct nilfs_sc_info *sci = nilfs->ns_writer; 236 237 if (ti->ti_flags & NILFS_TI_COMMIT) 238 nilfs_segctor_start_timer(sci); 239 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark) 240 nilfs_segctor_do_flush(sci, 0); 241 } 242 up_read(&nilfs->ns_segctor_sem); 243 current->journal_info = ti->ti_save; 244 245 if (ti->ti_flags & NILFS_TI_SYNC) 246 err = nilfs_construct_segment(sb); 247 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 248 kmem_cache_free(nilfs_transaction_cachep, ti); 249 return err; 250 } 251 252 void nilfs_transaction_abort(struct super_block *sb) 253 { 254 struct nilfs_transaction_info *ti = current->journal_info; 255 struct the_nilfs *nilfs = sb->s_fs_info; 256 257 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 258 if (ti->ti_count > 0) { 259 ti->ti_count--; 260 return; 261 } 262 up_read(&nilfs->ns_segctor_sem); 263 264 current->journal_info = ti->ti_save; 265 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 266 kmem_cache_free(nilfs_transaction_cachep, ti); 267 } 268 269 void nilfs_relax_pressure_in_lock(struct super_block *sb) 270 { 271 struct the_nilfs *nilfs = sb->s_fs_info; 272 struct nilfs_sc_info *sci = nilfs->ns_writer; 273 274 if (!sci || !sci->sc_flush_request) 275 return; 276 277 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 278 up_read(&nilfs->ns_segctor_sem); 279 280 down_write(&nilfs->ns_segctor_sem); 281 if (sci->sc_flush_request && 282 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) { 283 struct nilfs_transaction_info *ti = current->journal_info; 284 285 ti->ti_flags |= NILFS_TI_WRITER; 286 nilfs_segctor_do_immediate_flush(sci); 287 ti->ti_flags &= ~NILFS_TI_WRITER; 288 } 289 downgrade_write(&nilfs->ns_segctor_sem); 290 } 291 292 static void nilfs_transaction_lock(struct super_block *sb, 293 struct nilfs_transaction_info *ti, 294 int gcflag) 295 { 296 struct nilfs_transaction_info *cur_ti = current->journal_info; 297 struct the_nilfs *nilfs = sb->s_fs_info; 298 struct nilfs_sc_info *sci = nilfs->ns_writer; 299 300 WARN_ON(cur_ti); 301 ti->ti_flags = NILFS_TI_WRITER; 302 ti->ti_count = 0; 303 ti->ti_save = cur_ti; 304 ti->ti_magic = NILFS_TI_MAGIC; 305 INIT_LIST_HEAD(&ti->ti_garbage); 306 current->journal_info = ti; 307 308 for (;;) { 309 down_write(&nilfs->ns_segctor_sem); 310 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) 311 break; 312 313 nilfs_segctor_do_immediate_flush(sci); 314 315 up_write(&nilfs->ns_segctor_sem); 316 yield(); 317 } 318 if (gcflag) 319 ti->ti_flags |= NILFS_TI_GC; 320 } 321 322 static void nilfs_transaction_unlock(struct super_block *sb) 323 { 324 struct nilfs_transaction_info *ti = current->journal_info; 325 struct the_nilfs *nilfs = sb->s_fs_info; 326 327 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 328 BUG_ON(ti->ti_count > 0); 329 330 up_write(&nilfs->ns_segctor_sem); 331 current->journal_info = ti->ti_save; 332 if (!list_empty(&ti->ti_garbage)) 333 nilfs_dispose_list(nilfs, &ti->ti_garbage, 0); 334 } 335 336 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci, 337 struct nilfs_segsum_pointer *ssp, 338 unsigned bytes) 339 { 340 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 341 unsigned blocksize = sci->sc_super->s_blocksize; 342 void *p; 343 344 if (unlikely(ssp->offset + bytes > blocksize)) { 345 ssp->offset = 0; 346 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh, 347 &segbuf->sb_segsum_buffers)); 348 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh); 349 } 350 p = ssp->bh->b_data + ssp->offset; 351 ssp->offset += bytes; 352 return p; 353 } 354 355 /** 356 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer 357 * @sci: nilfs_sc_info 358 */ 359 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci) 360 { 361 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 362 struct buffer_head *sumbh; 363 unsigned sumbytes; 364 unsigned flags = 0; 365 int err; 366 367 if (nilfs_doing_gc()) 368 flags = NILFS_SS_GC; 369 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno); 370 if (unlikely(err)) 371 return err; 372 373 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); 374 sumbytes = segbuf->sb_sum.sumbytes; 375 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes; 376 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes; 377 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; 378 return 0; 379 } 380 381 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci) 382 { 383 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; 384 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs)) 385 return -E2BIG; /* The current segment is filled up 386 (internal code) */ 387 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg); 388 return nilfs_segctor_reset_segment_buffer(sci); 389 } 390 391 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci) 392 { 393 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 394 int err; 395 396 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) { 397 err = nilfs_segctor_feed_segment(sci); 398 if (err) 399 return err; 400 segbuf = sci->sc_curseg; 401 } 402 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root); 403 if (likely(!err)) 404 segbuf->sb_sum.flags |= NILFS_SS_SR; 405 return err; 406 } 407 408 /* 409 * Functions for making segment summary and payloads 410 */ 411 static int nilfs_segctor_segsum_block_required( 412 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp, 413 unsigned binfo_size) 414 { 415 unsigned blocksize = sci->sc_super->s_blocksize; 416 /* Size of finfo and binfo is enough small against blocksize */ 417 418 return ssp->offset + binfo_size + 419 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) > 420 blocksize; 421 } 422 423 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci, 424 struct inode *inode) 425 { 426 sci->sc_curseg->sb_sum.nfinfo++; 427 sci->sc_binfo_ptr = sci->sc_finfo_ptr; 428 nilfs_segctor_map_segsum_entry( 429 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo)); 430 431 if (NILFS_I(inode)->i_root && 432 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 433 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 434 /* skip finfo */ 435 } 436 437 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci, 438 struct inode *inode) 439 { 440 struct nilfs_finfo *finfo; 441 struct nilfs_inode_info *ii; 442 struct nilfs_segment_buffer *segbuf; 443 __u64 cno; 444 445 if (sci->sc_blk_cnt == 0) 446 return; 447 448 ii = NILFS_I(inode); 449 450 if (test_bit(NILFS_I_GCINODE, &ii->i_state)) 451 cno = ii->i_cno; 452 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) 453 cno = 0; 454 else 455 cno = sci->sc_cno; 456 457 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr, 458 sizeof(*finfo)); 459 finfo->fi_ino = cpu_to_le64(inode->i_ino); 460 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt); 461 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt); 462 finfo->fi_cno = cpu_to_le64(cno); 463 464 segbuf = sci->sc_curseg; 465 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset + 466 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1); 467 sci->sc_finfo_ptr = sci->sc_binfo_ptr; 468 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; 469 } 470 471 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci, 472 struct buffer_head *bh, 473 struct inode *inode, 474 unsigned binfo_size) 475 { 476 struct nilfs_segment_buffer *segbuf; 477 int required, err = 0; 478 479 retry: 480 segbuf = sci->sc_curseg; 481 required = nilfs_segctor_segsum_block_required( 482 sci, &sci->sc_binfo_ptr, binfo_size); 483 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) { 484 nilfs_segctor_end_finfo(sci, inode); 485 err = nilfs_segctor_feed_segment(sci); 486 if (err) 487 return err; 488 goto retry; 489 } 490 if (unlikely(required)) { 491 err = nilfs_segbuf_extend_segsum(segbuf); 492 if (unlikely(err)) 493 goto failed; 494 } 495 if (sci->sc_blk_cnt == 0) 496 nilfs_segctor_begin_finfo(sci, inode); 497 498 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size); 499 /* Substitution to vblocknr is delayed until update_blocknr() */ 500 nilfs_segbuf_add_file_buffer(segbuf, bh); 501 sci->sc_blk_cnt++; 502 failed: 503 return err; 504 } 505 506 /* 507 * Callback functions that enumerate, mark, and collect dirty blocks 508 */ 509 static int nilfs_collect_file_data(struct nilfs_sc_info *sci, 510 struct buffer_head *bh, struct inode *inode) 511 { 512 int err; 513 514 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 515 if (err < 0) 516 return err; 517 518 err = nilfs_segctor_add_file_block(sci, bh, inode, 519 sizeof(struct nilfs_binfo_v)); 520 if (!err) 521 sci->sc_datablk_cnt++; 522 return err; 523 } 524 525 static int nilfs_collect_file_node(struct nilfs_sc_info *sci, 526 struct buffer_head *bh, 527 struct inode *inode) 528 { 529 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 530 } 531 532 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci, 533 struct buffer_head *bh, 534 struct inode *inode) 535 { 536 WARN_ON(!buffer_dirty(bh)); 537 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); 538 } 539 540 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci, 541 struct nilfs_segsum_pointer *ssp, 542 union nilfs_binfo *binfo) 543 { 544 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry( 545 sci, ssp, sizeof(*binfo_v)); 546 *binfo_v = binfo->bi_v; 547 } 548 549 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci, 550 struct nilfs_segsum_pointer *ssp, 551 union nilfs_binfo *binfo) 552 { 553 __le64 *vblocknr = nilfs_segctor_map_segsum_entry( 554 sci, ssp, sizeof(*vblocknr)); 555 *vblocknr = binfo->bi_v.bi_vblocknr; 556 } 557 558 static struct nilfs_sc_operations nilfs_sc_file_ops = { 559 .collect_data = nilfs_collect_file_data, 560 .collect_node = nilfs_collect_file_node, 561 .collect_bmap = nilfs_collect_file_bmap, 562 .write_data_binfo = nilfs_write_file_data_binfo, 563 .write_node_binfo = nilfs_write_file_node_binfo, 564 }; 565 566 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci, 567 struct buffer_head *bh, struct inode *inode) 568 { 569 int err; 570 571 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 572 if (err < 0) 573 return err; 574 575 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); 576 if (!err) 577 sci->sc_datablk_cnt++; 578 return err; 579 } 580 581 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci, 582 struct buffer_head *bh, struct inode *inode) 583 { 584 WARN_ON(!buffer_dirty(bh)); 585 return nilfs_segctor_add_file_block(sci, bh, inode, 586 sizeof(struct nilfs_binfo_dat)); 587 } 588 589 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci, 590 struct nilfs_segsum_pointer *ssp, 591 union nilfs_binfo *binfo) 592 { 593 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp, 594 sizeof(*blkoff)); 595 *blkoff = binfo->bi_dat.bi_blkoff; 596 } 597 598 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci, 599 struct nilfs_segsum_pointer *ssp, 600 union nilfs_binfo *binfo) 601 { 602 struct nilfs_binfo_dat *binfo_dat = 603 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat)); 604 *binfo_dat = binfo->bi_dat; 605 } 606 607 static struct nilfs_sc_operations nilfs_sc_dat_ops = { 608 .collect_data = nilfs_collect_dat_data, 609 .collect_node = nilfs_collect_file_node, 610 .collect_bmap = nilfs_collect_dat_bmap, 611 .write_data_binfo = nilfs_write_dat_data_binfo, 612 .write_node_binfo = nilfs_write_dat_node_binfo, 613 }; 614 615 static struct nilfs_sc_operations nilfs_sc_dsync_ops = { 616 .collect_data = nilfs_collect_file_data, 617 .collect_node = NULL, 618 .collect_bmap = NULL, 619 .write_data_binfo = nilfs_write_file_data_binfo, 620 .write_node_binfo = NULL, 621 }; 622 623 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode, 624 struct list_head *listp, 625 size_t nlimit, 626 loff_t start, loff_t end) 627 { 628 struct address_space *mapping = inode->i_mapping; 629 struct pagevec pvec; 630 pgoff_t index = 0, last = ULONG_MAX; 631 size_t ndirties = 0; 632 int i; 633 634 if (unlikely(start != 0 || end != LLONG_MAX)) { 635 /* 636 * A valid range is given for sync-ing data pages. The 637 * range is rounded to per-page; extra dirty buffers 638 * may be included if blocksize < pagesize. 639 */ 640 index = start >> PAGE_SHIFT; 641 last = end >> PAGE_SHIFT; 642 } 643 pagevec_init(&pvec, 0); 644 repeat: 645 if (unlikely(index > last) || 646 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 647 min_t(pgoff_t, last - index, 648 PAGEVEC_SIZE - 1) + 1)) 649 return ndirties; 650 651 for (i = 0; i < pagevec_count(&pvec); i++) { 652 struct buffer_head *bh, *head; 653 struct page *page = pvec.pages[i]; 654 655 if (unlikely(page->index > last)) 656 break; 657 658 if (mapping->host) { 659 lock_page(page); 660 if (!page_has_buffers(page)) 661 create_empty_buffers(page, 662 1 << inode->i_blkbits, 0); 663 unlock_page(page); 664 } 665 666 bh = head = page_buffers(page); 667 do { 668 if (!buffer_dirty(bh)) 669 continue; 670 get_bh(bh); 671 list_add_tail(&bh->b_assoc_buffers, listp); 672 ndirties++; 673 if (unlikely(ndirties >= nlimit)) { 674 pagevec_release(&pvec); 675 cond_resched(); 676 return ndirties; 677 } 678 } while (bh = bh->b_this_page, bh != head); 679 } 680 pagevec_release(&pvec); 681 cond_resched(); 682 goto repeat; 683 } 684 685 static void nilfs_lookup_dirty_node_buffers(struct inode *inode, 686 struct list_head *listp) 687 { 688 struct nilfs_inode_info *ii = NILFS_I(inode); 689 struct address_space *mapping = &ii->i_btnode_cache; 690 struct pagevec pvec; 691 struct buffer_head *bh, *head; 692 unsigned int i; 693 pgoff_t index = 0; 694 695 pagevec_init(&pvec, 0); 696 697 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 698 PAGEVEC_SIZE)) { 699 for (i = 0; i < pagevec_count(&pvec); i++) { 700 bh = head = page_buffers(pvec.pages[i]); 701 do { 702 if (buffer_dirty(bh)) { 703 get_bh(bh); 704 list_add_tail(&bh->b_assoc_buffers, 705 listp); 706 } 707 bh = bh->b_this_page; 708 } while (bh != head); 709 } 710 pagevec_release(&pvec); 711 cond_resched(); 712 } 713 } 714 715 static void nilfs_dispose_list(struct the_nilfs *nilfs, 716 struct list_head *head, int force) 717 { 718 struct nilfs_inode_info *ii, *n; 719 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii; 720 unsigned nv = 0; 721 722 while (!list_empty(head)) { 723 spin_lock(&nilfs->ns_inode_lock); 724 list_for_each_entry_safe(ii, n, head, i_dirty) { 725 list_del_init(&ii->i_dirty); 726 if (force) { 727 if (unlikely(ii->i_bh)) { 728 brelse(ii->i_bh); 729 ii->i_bh = NULL; 730 } 731 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) { 732 set_bit(NILFS_I_QUEUED, &ii->i_state); 733 list_add_tail(&ii->i_dirty, 734 &nilfs->ns_dirty_files); 735 continue; 736 } 737 ivec[nv++] = ii; 738 if (nv == SC_N_INODEVEC) 739 break; 740 } 741 spin_unlock(&nilfs->ns_inode_lock); 742 743 for (pii = ivec; nv > 0; pii++, nv--) 744 iput(&(*pii)->vfs_inode); 745 } 746 } 747 748 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs, 749 struct nilfs_root *root) 750 { 751 int ret = 0; 752 753 if (nilfs_mdt_fetch_dirty(root->ifile)) 754 ret++; 755 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile)) 756 ret++; 757 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile)) 758 ret++; 759 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat)) 760 ret++; 761 return ret; 762 } 763 764 static int nilfs_segctor_clean(struct nilfs_sc_info *sci) 765 { 766 return list_empty(&sci->sc_dirty_files) && 767 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) && 768 sci->sc_nfreesegs == 0 && 769 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes)); 770 } 771 772 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci) 773 { 774 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 775 int ret = 0; 776 777 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 778 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 779 780 spin_lock(&nilfs->ns_inode_lock); 781 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci)) 782 ret++; 783 784 spin_unlock(&nilfs->ns_inode_lock); 785 return ret; 786 } 787 788 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci) 789 { 790 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 791 792 nilfs_mdt_clear_dirty(sci->sc_root->ifile); 793 nilfs_mdt_clear_dirty(nilfs->ns_cpfile); 794 nilfs_mdt_clear_dirty(nilfs->ns_sufile); 795 nilfs_mdt_clear_dirty(nilfs->ns_dat); 796 } 797 798 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci) 799 { 800 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 801 struct buffer_head *bh_cp; 802 struct nilfs_checkpoint *raw_cp; 803 int err; 804 805 /* XXX: this interface will be changed */ 806 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1, 807 &raw_cp, &bh_cp); 808 if (likely(!err)) { 809 /* The following code is duplicated with cpfile. But, it is 810 needed to collect the checkpoint even if it was not newly 811 created */ 812 nilfs_mdt_mark_buffer_dirty(bh_cp); 813 nilfs_mdt_mark_dirty(nilfs->ns_cpfile); 814 nilfs_cpfile_put_checkpoint( 815 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 816 } else 817 WARN_ON(err == -EINVAL || err == -ENOENT); 818 819 return err; 820 } 821 822 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci) 823 { 824 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 825 struct buffer_head *bh_cp; 826 struct nilfs_checkpoint *raw_cp; 827 int err; 828 829 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0, 830 &raw_cp, &bh_cp); 831 if (unlikely(err)) { 832 WARN_ON(err == -EINVAL || err == -ENOENT); 833 goto failed_ibh; 834 } 835 raw_cp->cp_snapshot_list.ssl_next = 0; 836 raw_cp->cp_snapshot_list.ssl_prev = 0; 837 raw_cp->cp_inodes_count = 838 cpu_to_le64(atomic_read(&sci->sc_root->inodes_count)); 839 raw_cp->cp_blocks_count = 840 cpu_to_le64(atomic_read(&sci->sc_root->blocks_count)); 841 raw_cp->cp_nblk_inc = 842 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc); 843 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime); 844 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno); 845 846 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 847 nilfs_checkpoint_clear_minor(raw_cp); 848 else 849 nilfs_checkpoint_set_minor(raw_cp); 850 851 nilfs_write_inode_common(sci->sc_root->ifile, 852 &raw_cp->cp_ifile_inode, 1); 853 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 854 return 0; 855 856 failed_ibh: 857 return err; 858 } 859 860 static void nilfs_fill_in_file_bmap(struct inode *ifile, 861 struct nilfs_inode_info *ii) 862 863 { 864 struct buffer_head *ibh; 865 struct nilfs_inode *raw_inode; 866 867 if (test_bit(NILFS_I_BMAP, &ii->i_state)) { 868 ibh = ii->i_bh; 869 BUG_ON(!ibh); 870 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino, 871 ibh); 872 nilfs_bmap_write(ii->i_bmap, raw_inode); 873 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh); 874 } 875 } 876 877 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci) 878 { 879 struct nilfs_inode_info *ii; 880 881 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) { 882 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii); 883 set_bit(NILFS_I_COLLECTED, &ii->i_state); 884 } 885 } 886 887 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci, 888 struct the_nilfs *nilfs) 889 { 890 struct buffer_head *bh_sr; 891 struct nilfs_super_root *raw_sr; 892 unsigned isz = nilfs->ns_inode_size; 893 894 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root; 895 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 896 897 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES); 898 raw_sr->sr_nongc_ctime 899 = cpu_to_le64(nilfs_doing_gc() ? 900 nilfs->ns_nongc_ctime : sci->sc_seg_ctime); 901 raw_sr->sr_flags = 0; 902 903 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr + 904 NILFS_SR_DAT_OFFSET(isz), 1); 905 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr + 906 NILFS_SR_CPFILE_OFFSET(isz), 1); 907 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr + 908 NILFS_SR_SUFILE_OFFSET(isz), 1); 909 } 910 911 static void nilfs_redirty_inodes(struct list_head *head) 912 { 913 struct nilfs_inode_info *ii; 914 915 list_for_each_entry(ii, head, i_dirty) { 916 if (test_bit(NILFS_I_COLLECTED, &ii->i_state)) 917 clear_bit(NILFS_I_COLLECTED, &ii->i_state); 918 } 919 } 920 921 static void nilfs_drop_collected_inodes(struct list_head *head) 922 { 923 struct nilfs_inode_info *ii; 924 925 list_for_each_entry(ii, head, i_dirty) { 926 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state)) 927 continue; 928 929 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state); 930 set_bit(NILFS_I_UPDATED, &ii->i_state); 931 } 932 } 933 934 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci, 935 struct inode *inode, 936 struct list_head *listp, 937 int (*collect)(struct nilfs_sc_info *, 938 struct buffer_head *, 939 struct inode *)) 940 { 941 struct buffer_head *bh, *n; 942 int err = 0; 943 944 if (collect) { 945 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) { 946 list_del_init(&bh->b_assoc_buffers); 947 err = collect(sci, bh, inode); 948 brelse(bh); 949 if (unlikely(err)) 950 goto dispose_buffers; 951 } 952 return 0; 953 } 954 955 dispose_buffers: 956 while (!list_empty(listp)) { 957 bh = list_entry(listp->next, struct buffer_head, 958 b_assoc_buffers); 959 list_del_init(&bh->b_assoc_buffers); 960 brelse(bh); 961 } 962 return err; 963 } 964 965 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci) 966 { 967 /* Remaining number of blocks within segment buffer */ 968 return sci->sc_segbuf_nblocks - 969 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks); 970 } 971 972 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci, 973 struct inode *inode, 974 struct nilfs_sc_operations *sc_ops) 975 { 976 LIST_HEAD(data_buffers); 977 LIST_HEAD(node_buffers); 978 int err; 979 980 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { 981 size_t n, rest = nilfs_segctor_buffer_rest(sci); 982 983 n = nilfs_lookup_dirty_data_buffers( 984 inode, &data_buffers, rest + 1, 0, LLONG_MAX); 985 if (n > rest) { 986 err = nilfs_segctor_apply_buffers( 987 sci, inode, &data_buffers, 988 sc_ops->collect_data); 989 BUG_ON(!err); /* always receive -E2BIG or true error */ 990 goto break_or_fail; 991 } 992 } 993 nilfs_lookup_dirty_node_buffers(inode, &node_buffers); 994 995 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { 996 err = nilfs_segctor_apply_buffers( 997 sci, inode, &data_buffers, sc_ops->collect_data); 998 if (unlikely(err)) { 999 /* dispose node list */ 1000 nilfs_segctor_apply_buffers( 1001 sci, inode, &node_buffers, NULL); 1002 goto break_or_fail; 1003 } 1004 sci->sc_stage.flags |= NILFS_CF_NODE; 1005 } 1006 /* Collect node */ 1007 err = nilfs_segctor_apply_buffers( 1008 sci, inode, &node_buffers, sc_ops->collect_node); 1009 if (unlikely(err)) 1010 goto break_or_fail; 1011 1012 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers); 1013 err = nilfs_segctor_apply_buffers( 1014 sci, inode, &node_buffers, sc_ops->collect_bmap); 1015 if (unlikely(err)) 1016 goto break_or_fail; 1017 1018 nilfs_segctor_end_finfo(sci, inode); 1019 sci->sc_stage.flags &= ~NILFS_CF_NODE; 1020 1021 break_or_fail: 1022 return err; 1023 } 1024 1025 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci, 1026 struct inode *inode) 1027 { 1028 LIST_HEAD(data_buffers); 1029 size_t n, rest = nilfs_segctor_buffer_rest(sci); 1030 int err; 1031 1032 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1, 1033 sci->sc_dsync_start, 1034 sci->sc_dsync_end); 1035 1036 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers, 1037 nilfs_collect_file_data); 1038 if (!err) { 1039 nilfs_segctor_end_finfo(sci, inode); 1040 BUG_ON(n > rest); 1041 /* always receive -E2BIG or true error if n > rest */ 1042 } 1043 return err; 1044 } 1045 1046 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode) 1047 { 1048 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1049 struct list_head *head; 1050 struct nilfs_inode_info *ii; 1051 size_t ndone; 1052 int err = 0; 1053 1054 switch (sci->sc_stage.scnt) { 1055 case NILFS_ST_INIT: 1056 /* Pre-processes */ 1057 sci->sc_stage.flags = 0; 1058 1059 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) { 1060 sci->sc_nblk_inc = 0; 1061 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN; 1062 if (mode == SC_LSEG_DSYNC) { 1063 sci->sc_stage.scnt = NILFS_ST_DSYNC; 1064 goto dsync_mode; 1065 } 1066 } 1067 1068 sci->sc_stage.dirty_file_ptr = NULL; 1069 sci->sc_stage.gc_inode_ptr = NULL; 1070 if (mode == SC_FLUSH_DAT) { 1071 sci->sc_stage.scnt = NILFS_ST_DAT; 1072 goto dat_stage; 1073 } 1074 sci->sc_stage.scnt++; /* Fall through */ 1075 case NILFS_ST_GC: 1076 if (nilfs_doing_gc()) { 1077 head = &sci->sc_gc_inodes; 1078 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr, 1079 head, i_dirty); 1080 list_for_each_entry_continue(ii, head, i_dirty) { 1081 err = nilfs_segctor_scan_file( 1082 sci, &ii->vfs_inode, 1083 &nilfs_sc_file_ops); 1084 if (unlikely(err)) { 1085 sci->sc_stage.gc_inode_ptr = list_entry( 1086 ii->i_dirty.prev, 1087 struct nilfs_inode_info, 1088 i_dirty); 1089 goto break_or_fail; 1090 } 1091 set_bit(NILFS_I_COLLECTED, &ii->i_state); 1092 } 1093 sci->sc_stage.gc_inode_ptr = NULL; 1094 } 1095 sci->sc_stage.scnt++; /* Fall through */ 1096 case NILFS_ST_FILE: 1097 head = &sci->sc_dirty_files; 1098 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head, 1099 i_dirty); 1100 list_for_each_entry_continue(ii, head, i_dirty) { 1101 clear_bit(NILFS_I_DIRTY, &ii->i_state); 1102 1103 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode, 1104 &nilfs_sc_file_ops); 1105 if (unlikely(err)) { 1106 sci->sc_stage.dirty_file_ptr = 1107 list_entry(ii->i_dirty.prev, 1108 struct nilfs_inode_info, 1109 i_dirty); 1110 goto break_or_fail; 1111 } 1112 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */ 1113 /* XXX: required ? */ 1114 } 1115 sci->sc_stage.dirty_file_ptr = NULL; 1116 if (mode == SC_FLUSH_FILE) { 1117 sci->sc_stage.scnt = NILFS_ST_DONE; 1118 return 0; 1119 } 1120 sci->sc_stage.scnt++; 1121 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED; 1122 /* Fall through */ 1123 case NILFS_ST_IFILE: 1124 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile, 1125 &nilfs_sc_file_ops); 1126 if (unlikely(err)) 1127 break; 1128 sci->sc_stage.scnt++; 1129 /* Creating a checkpoint */ 1130 err = nilfs_segctor_create_checkpoint(sci); 1131 if (unlikely(err)) 1132 break; 1133 /* Fall through */ 1134 case NILFS_ST_CPFILE: 1135 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile, 1136 &nilfs_sc_file_ops); 1137 if (unlikely(err)) 1138 break; 1139 sci->sc_stage.scnt++; /* Fall through */ 1140 case NILFS_ST_SUFILE: 1141 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs, 1142 sci->sc_nfreesegs, &ndone); 1143 if (unlikely(err)) { 1144 nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1145 sci->sc_freesegs, ndone, 1146 NULL); 1147 break; 1148 } 1149 sci->sc_stage.flags |= NILFS_CF_SUFREED; 1150 1151 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile, 1152 &nilfs_sc_file_ops); 1153 if (unlikely(err)) 1154 break; 1155 sci->sc_stage.scnt++; /* Fall through */ 1156 case NILFS_ST_DAT: 1157 dat_stage: 1158 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat, 1159 &nilfs_sc_dat_ops); 1160 if (unlikely(err)) 1161 break; 1162 if (mode == SC_FLUSH_DAT) { 1163 sci->sc_stage.scnt = NILFS_ST_DONE; 1164 return 0; 1165 } 1166 sci->sc_stage.scnt++; /* Fall through */ 1167 case NILFS_ST_SR: 1168 if (mode == SC_LSEG_SR) { 1169 /* Appending a super root */ 1170 err = nilfs_segctor_add_super_root(sci); 1171 if (unlikely(err)) 1172 break; 1173 } 1174 /* End of a logical segment */ 1175 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; 1176 sci->sc_stage.scnt = NILFS_ST_DONE; 1177 return 0; 1178 case NILFS_ST_DSYNC: 1179 dsync_mode: 1180 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT; 1181 ii = sci->sc_dsync_inode; 1182 if (!test_bit(NILFS_I_BUSY, &ii->i_state)) 1183 break; 1184 1185 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode); 1186 if (unlikely(err)) 1187 break; 1188 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; 1189 sci->sc_stage.scnt = NILFS_ST_DONE; 1190 return 0; 1191 case NILFS_ST_DONE: 1192 return 0; 1193 default: 1194 BUG(); 1195 } 1196 1197 break_or_fail: 1198 return err; 1199 } 1200 1201 /** 1202 * nilfs_segctor_begin_construction - setup segment buffer to make a new log 1203 * @sci: nilfs_sc_info 1204 * @nilfs: nilfs object 1205 */ 1206 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci, 1207 struct the_nilfs *nilfs) 1208 { 1209 struct nilfs_segment_buffer *segbuf, *prev; 1210 __u64 nextnum; 1211 int err, alloc = 0; 1212 1213 segbuf = nilfs_segbuf_new(sci->sc_super); 1214 if (unlikely(!segbuf)) 1215 return -ENOMEM; 1216 1217 if (list_empty(&sci->sc_write_logs)) { 1218 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 1219 nilfs->ns_pseg_offset, nilfs); 1220 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { 1221 nilfs_shift_to_next_segment(nilfs); 1222 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs); 1223 } 1224 1225 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq; 1226 nextnum = nilfs->ns_nextnum; 1227 1228 if (nilfs->ns_segnum == nilfs->ns_nextnum) 1229 /* Start from the head of a new full segment */ 1230 alloc++; 1231 } else { 1232 /* Continue logs */ 1233 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1234 nilfs_segbuf_map_cont(segbuf, prev); 1235 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq; 1236 nextnum = prev->sb_nextnum; 1237 1238 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { 1239 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); 1240 segbuf->sb_sum.seg_seq++; 1241 alloc++; 1242 } 1243 } 1244 1245 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum); 1246 if (err) 1247 goto failed; 1248 1249 if (alloc) { 1250 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum); 1251 if (err) 1252 goto failed; 1253 } 1254 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs); 1255 1256 BUG_ON(!list_empty(&sci->sc_segbufs)); 1257 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs); 1258 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks; 1259 return 0; 1260 1261 failed: 1262 nilfs_segbuf_free(segbuf); 1263 return err; 1264 } 1265 1266 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci, 1267 struct the_nilfs *nilfs, int nadd) 1268 { 1269 struct nilfs_segment_buffer *segbuf, *prev; 1270 struct inode *sufile = nilfs->ns_sufile; 1271 __u64 nextnextnum; 1272 LIST_HEAD(list); 1273 int err, ret, i; 1274 1275 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs); 1276 /* 1277 * Since the segment specified with nextnum might be allocated during 1278 * the previous construction, the buffer including its segusage may 1279 * not be dirty. The following call ensures that the buffer is dirty 1280 * and will pin the buffer on memory until the sufile is written. 1281 */ 1282 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum); 1283 if (unlikely(err)) 1284 return err; 1285 1286 for (i = 0; i < nadd; i++) { 1287 /* extend segment info */ 1288 err = -ENOMEM; 1289 segbuf = nilfs_segbuf_new(sci->sc_super); 1290 if (unlikely(!segbuf)) 1291 goto failed; 1292 1293 /* map this buffer to region of segment on-disk */ 1294 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); 1295 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks; 1296 1297 /* allocate the next next full segment */ 1298 err = nilfs_sufile_alloc(sufile, &nextnextnum); 1299 if (unlikely(err)) 1300 goto failed_segbuf; 1301 1302 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1; 1303 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs); 1304 1305 list_add_tail(&segbuf->sb_list, &list); 1306 prev = segbuf; 1307 } 1308 list_splice_tail(&list, &sci->sc_segbufs); 1309 return 0; 1310 1311 failed_segbuf: 1312 nilfs_segbuf_free(segbuf); 1313 failed: 1314 list_for_each_entry(segbuf, &list, sb_list) { 1315 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1316 WARN_ON(ret); /* never fails */ 1317 } 1318 nilfs_destroy_logs(&list); 1319 return err; 1320 } 1321 1322 static void nilfs_free_incomplete_logs(struct list_head *logs, 1323 struct the_nilfs *nilfs) 1324 { 1325 struct nilfs_segment_buffer *segbuf, *prev; 1326 struct inode *sufile = nilfs->ns_sufile; 1327 int ret; 1328 1329 segbuf = NILFS_FIRST_SEGBUF(logs); 1330 if (nilfs->ns_nextnum != segbuf->sb_nextnum) { 1331 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1332 WARN_ON(ret); /* never fails */ 1333 } 1334 if (atomic_read(&segbuf->sb_err)) { 1335 /* Case 1: The first segment failed */ 1336 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start) 1337 /* Case 1a: Partial segment appended into an existing 1338 segment */ 1339 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start, 1340 segbuf->sb_fseg_end); 1341 else /* Case 1b: New full segment */ 1342 set_nilfs_discontinued(nilfs); 1343 } 1344 1345 prev = segbuf; 1346 list_for_each_entry_continue(segbuf, logs, sb_list) { 1347 if (prev->sb_nextnum != segbuf->sb_nextnum) { 1348 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1349 WARN_ON(ret); /* never fails */ 1350 } 1351 if (atomic_read(&segbuf->sb_err) && 1352 segbuf->sb_segnum != nilfs->ns_nextnum) 1353 /* Case 2: extended segment (!= next) failed */ 1354 nilfs_sufile_set_error(sufile, segbuf->sb_segnum); 1355 prev = segbuf; 1356 } 1357 } 1358 1359 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci, 1360 struct inode *sufile) 1361 { 1362 struct nilfs_segment_buffer *segbuf; 1363 unsigned long live_blocks; 1364 int ret; 1365 1366 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1367 live_blocks = segbuf->sb_sum.nblocks + 1368 (segbuf->sb_pseg_start - segbuf->sb_fseg_start); 1369 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1370 live_blocks, 1371 sci->sc_seg_ctime); 1372 WARN_ON(ret); /* always succeed because the segusage is dirty */ 1373 } 1374 } 1375 1376 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile) 1377 { 1378 struct nilfs_segment_buffer *segbuf; 1379 int ret; 1380 1381 segbuf = NILFS_FIRST_SEGBUF(logs); 1382 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1383 segbuf->sb_pseg_start - 1384 segbuf->sb_fseg_start, 0); 1385 WARN_ON(ret); /* always succeed because the segusage is dirty */ 1386 1387 list_for_each_entry_continue(segbuf, logs, sb_list) { 1388 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1389 0, 0); 1390 WARN_ON(ret); /* always succeed */ 1391 } 1392 } 1393 1394 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci, 1395 struct nilfs_segment_buffer *last, 1396 struct inode *sufile) 1397 { 1398 struct nilfs_segment_buffer *segbuf = last; 1399 int ret; 1400 1401 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) { 1402 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks; 1403 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1404 WARN_ON(ret); 1405 } 1406 nilfs_truncate_logs(&sci->sc_segbufs, last); 1407 } 1408 1409 1410 static int nilfs_segctor_collect(struct nilfs_sc_info *sci, 1411 struct the_nilfs *nilfs, int mode) 1412 { 1413 struct nilfs_cstage prev_stage = sci->sc_stage; 1414 int err, nadd = 1; 1415 1416 /* Collection retry loop */ 1417 for (;;) { 1418 sci->sc_nblk_this_inc = 0; 1419 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs); 1420 1421 err = nilfs_segctor_reset_segment_buffer(sci); 1422 if (unlikely(err)) 1423 goto failed; 1424 1425 err = nilfs_segctor_collect_blocks(sci, mode); 1426 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; 1427 if (!err) 1428 break; 1429 1430 if (unlikely(err != -E2BIG)) 1431 goto failed; 1432 1433 /* The current segment is filled up */ 1434 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE) 1435 break; 1436 1437 nilfs_clear_logs(&sci->sc_segbufs); 1438 1439 err = nilfs_segctor_extend_segments(sci, nilfs, nadd); 1440 if (unlikely(err)) 1441 return err; 1442 1443 if (sci->sc_stage.flags & NILFS_CF_SUFREED) { 1444 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1445 sci->sc_freesegs, 1446 sci->sc_nfreesegs, 1447 NULL); 1448 WARN_ON(err); /* do not happen */ 1449 } 1450 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA); 1451 sci->sc_stage = prev_stage; 1452 } 1453 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile); 1454 return 0; 1455 1456 failed: 1457 return err; 1458 } 1459 1460 static void nilfs_list_replace_buffer(struct buffer_head *old_bh, 1461 struct buffer_head *new_bh) 1462 { 1463 BUG_ON(!list_empty(&new_bh->b_assoc_buffers)); 1464 1465 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers); 1466 /* The caller must release old_bh */ 1467 } 1468 1469 static int 1470 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci, 1471 struct nilfs_segment_buffer *segbuf, 1472 int mode) 1473 { 1474 struct inode *inode = NULL; 1475 sector_t blocknr; 1476 unsigned long nfinfo = segbuf->sb_sum.nfinfo; 1477 unsigned long nblocks = 0, ndatablk = 0; 1478 struct nilfs_sc_operations *sc_op = NULL; 1479 struct nilfs_segsum_pointer ssp; 1480 struct nilfs_finfo *finfo = NULL; 1481 union nilfs_binfo binfo; 1482 struct buffer_head *bh, *bh_org; 1483 ino_t ino = 0; 1484 int err = 0; 1485 1486 if (!nfinfo) 1487 goto out; 1488 1489 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk; 1490 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); 1491 ssp.offset = sizeof(struct nilfs_segment_summary); 1492 1493 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { 1494 if (bh == segbuf->sb_super_root) 1495 break; 1496 if (!finfo) { 1497 finfo = nilfs_segctor_map_segsum_entry( 1498 sci, &ssp, sizeof(*finfo)); 1499 ino = le64_to_cpu(finfo->fi_ino); 1500 nblocks = le32_to_cpu(finfo->fi_nblocks); 1501 ndatablk = le32_to_cpu(finfo->fi_ndatablk); 1502 1503 if (buffer_nilfs_node(bh)) 1504 inode = NILFS_BTNC_I(bh->b_page->mapping); 1505 else 1506 inode = NILFS_AS_I(bh->b_page->mapping); 1507 1508 if (mode == SC_LSEG_DSYNC) 1509 sc_op = &nilfs_sc_dsync_ops; 1510 else if (ino == NILFS_DAT_INO) 1511 sc_op = &nilfs_sc_dat_ops; 1512 else /* file blocks */ 1513 sc_op = &nilfs_sc_file_ops; 1514 } 1515 bh_org = bh; 1516 get_bh(bh_org); 1517 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr, 1518 &binfo); 1519 if (bh != bh_org) 1520 nilfs_list_replace_buffer(bh_org, bh); 1521 brelse(bh_org); 1522 if (unlikely(err)) 1523 goto failed_bmap; 1524 1525 if (ndatablk > 0) 1526 sc_op->write_data_binfo(sci, &ssp, &binfo); 1527 else 1528 sc_op->write_node_binfo(sci, &ssp, &binfo); 1529 1530 blocknr++; 1531 if (--nblocks == 0) { 1532 finfo = NULL; 1533 if (--nfinfo == 0) 1534 break; 1535 } else if (ndatablk > 0) 1536 ndatablk--; 1537 } 1538 out: 1539 return 0; 1540 1541 failed_bmap: 1542 return err; 1543 } 1544 1545 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode) 1546 { 1547 struct nilfs_segment_buffer *segbuf; 1548 int err; 1549 1550 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1551 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode); 1552 if (unlikely(err)) 1553 return err; 1554 nilfs_segbuf_fill_in_segsum(segbuf); 1555 } 1556 return 0; 1557 } 1558 1559 static int 1560 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out) 1561 { 1562 struct page *clone_page; 1563 struct buffer_head *bh, *head, *bh2; 1564 void *kaddr; 1565 1566 bh = head = page_buffers(page); 1567 1568 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0); 1569 if (unlikely(!clone_page)) 1570 return -ENOMEM; 1571 1572 bh2 = page_buffers(clone_page); 1573 kaddr = kmap_atomic(page, KM_USER0); 1574 do { 1575 if (list_empty(&bh->b_assoc_buffers)) 1576 continue; 1577 get_bh(bh2); 1578 page_cache_get(clone_page); /* for each bh */ 1579 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size); 1580 bh2->b_blocknr = bh->b_blocknr; 1581 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers); 1582 list_add_tail(&bh->b_assoc_buffers, out); 1583 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head); 1584 kunmap_atomic(kaddr, KM_USER0); 1585 1586 if (!TestSetPageWriteback(clone_page)) 1587 account_page_writeback(clone_page); 1588 unlock_page(clone_page); 1589 1590 return 0; 1591 } 1592 1593 static int nilfs_test_page_to_be_frozen(struct page *page) 1594 { 1595 struct address_space *mapping = page->mapping; 1596 1597 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode)) 1598 return 0; 1599 1600 if (page_mapped(page)) { 1601 ClearPageChecked(page); 1602 return 1; 1603 } 1604 return PageChecked(page); 1605 } 1606 1607 static int nilfs_begin_page_io(struct page *page, struct list_head *out) 1608 { 1609 if (!page || PageWriteback(page)) 1610 /* For split b-tree node pages, this function may be called 1611 twice. We ignore the 2nd or later calls by this check. */ 1612 return 0; 1613 1614 lock_page(page); 1615 clear_page_dirty_for_io(page); 1616 set_page_writeback(page); 1617 unlock_page(page); 1618 1619 if (nilfs_test_page_to_be_frozen(page)) { 1620 int err = nilfs_copy_replace_page_buffers(page, out); 1621 if (unlikely(err)) 1622 return err; 1623 } 1624 return 0; 1625 } 1626 1627 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci, 1628 struct page **failed_page) 1629 { 1630 struct nilfs_segment_buffer *segbuf; 1631 struct page *bd_page = NULL, *fs_page = NULL; 1632 struct list_head *list = &sci->sc_copied_buffers; 1633 int err; 1634 1635 *failed_page = NULL; 1636 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1637 struct buffer_head *bh; 1638 1639 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1640 b_assoc_buffers) { 1641 if (bh->b_page != bd_page) { 1642 if (bd_page) { 1643 lock_page(bd_page); 1644 clear_page_dirty_for_io(bd_page); 1645 set_page_writeback(bd_page); 1646 unlock_page(bd_page); 1647 } 1648 bd_page = bh->b_page; 1649 } 1650 } 1651 1652 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1653 b_assoc_buffers) { 1654 if (bh == segbuf->sb_super_root) { 1655 if (bh->b_page != bd_page) { 1656 lock_page(bd_page); 1657 clear_page_dirty_for_io(bd_page); 1658 set_page_writeback(bd_page); 1659 unlock_page(bd_page); 1660 bd_page = bh->b_page; 1661 } 1662 break; 1663 } 1664 if (bh->b_page != fs_page) { 1665 err = nilfs_begin_page_io(fs_page, list); 1666 if (unlikely(err)) { 1667 *failed_page = fs_page; 1668 goto out; 1669 } 1670 fs_page = bh->b_page; 1671 } 1672 } 1673 } 1674 if (bd_page) { 1675 lock_page(bd_page); 1676 clear_page_dirty_for_io(bd_page); 1677 set_page_writeback(bd_page); 1678 unlock_page(bd_page); 1679 } 1680 err = nilfs_begin_page_io(fs_page, list); 1681 if (unlikely(err)) 1682 *failed_page = fs_page; 1683 out: 1684 return err; 1685 } 1686 1687 static int nilfs_segctor_write(struct nilfs_sc_info *sci, 1688 struct the_nilfs *nilfs) 1689 { 1690 int ret; 1691 1692 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs); 1693 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs); 1694 return ret; 1695 } 1696 1697 static void __nilfs_end_page_io(struct page *page, int err) 1698 { 1699 if (!err) { 1700 if (!nilfs_page_buffers_clean(page)) 1701 __set_page_dirty_nobuffers(page); 1702 ClearPageError(page); 1703 } else { 1704 __set_page_dirty_nobuffers(page); 1705 SetPageError(page); 1706 } 1707 1708 if (buffer_nilfs_allocated(page_buffers(page))) { 1709 if (TestClearPageWriteback(page)) 1710 dec_zone_page_state(page, NR_WRITEBACK); 1711 } else 1712 end_page_writeback(page); 1713 } 1714 1715 static void nilfs_end_page_io(struct page *page, int err) 1716 { 1717 if (!page) 1718 return; 1719 1720 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) { 1721 /* 1722 * For b-tree node pages, this function may be called twice 1723 * or more because they might be split in a segment. 1724 */ 1725 if (PageDirty(page)) { 1726 /* 1727 * For pages holding split b-tree node buffers, dirty 1728 * flag on the buffers may be cleared discretely. 1729 * In that case, the page is once redirtied for 1730 * remaining buffers, and it must be cancelled if 1731 * all the buffers get cleaned later. 1732 */ 1733 lock_page(page); 1734 if (nilfs_page_buffers_clean(page)) 1735 __nilfs_clear_page_dirty(page); 1736 unlock_page(page); 1737 } 1738 return; 1739 } 1740 1741 __nilfs_end_page_io(page, err); 1742 } 1743 1744 static void nilfs_clear_copied_buffers(struct list_head *list, int err) 1745 { 1746 struct buffer_head *bh, *head; 1747 struct page *page; 1748 1749 while (!list_empty(list)) { 1750 bh = list_entry(list->next, struct buffer_head, 1751 b_assoc_buffers); 1752 page = bh->b_page; 1753 page_cache_get(page); 1754 head = bh = page_buffers(page); 1755 do { 1756 if (!list_empty(&bh->b_assoc_buffers)) { 1757 list_del_init(&bh->b_assoc_buffers); 1758 if (!err) { 1759 set_buffer_uptodate(bh); 1760 clear_buffer_dirty(bh); 1761 clear_buffer_delay(bh); 1762 clear_buffer_nilfs_volatile(bh); 1763 } 1764 brelse(bh); /* for b_assoc_buffers */ 1765 } 1766 } while ((bh = bh->b_this_page) != head); 1767 1768 __nilfs_end_page_io(page, err); 1769 page_cache_release(page); 1770 } 1771 } 1772 1773 static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page, 1774 int err) 1775 { 1776 struct nilfs_segment_buffer *segbuf; 1777 struct page *bd_page = NULL, *fs_page = NULL; 1778 struct buffer_head *bh; 1779 1780 if (list_empty(logs)) 1781 return; 1782 1783 list_for_each_entry(segbuf, logs, sb_list) { 1784 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1785 b_assoc_buffers) { 1786 if (bh->b_page != bd_page) { 1787 if (bd_page) 1788 end_page_writeback(bd_page); 1789 bd_page = bh->b_page; 1790 } 1791 } 1792 1793 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1794 b_assoc_buffers) { 1795 if (bh == segbuf->sb_super_root) { 1796 if (bh->b_page != bd_page) { 1797 end_page_writeback(bd_page); 1798 bd_page = bh->b_page; 1799 } 1800 break; 1801 } 1802 if (bh->b_page != fs_page) { 1803 nilfs_end_page_io(fs_page, err); 1804 if (fs_page && fs_page == failed_page) 1805 return; 1806 fs_page = bh->b_page; 1807 } 1808 } 1809 } 1810 if (bd_page) 1811 end_page_writeback(bd_page); 1812 1813 nilfs_end_page_io(fs_page, err); 1814 } 1815 1816 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci, 1817 struct the_nilfs *nilfs, int err) 1818 { 1819 LIST_HEAD(logs); 1820 int ret; 1821 1822 list_splice_tail_init(&sci->sc_write_logs, &logs); 1823 ret = nilfs_wait_on_logs(&logs); 1824 nilfs_abort_logs(&logs, NULL, ret ? : err); 1825 1826 list_splice_tail_init(&sci->sc_segbufs, &logs); 1827 nilfs_cancel_segusage(&logs, nilfs->ns_sufile); 1828 nilfs_free_incomplete_logs(&logs, nilfs); 1829 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err); 1830 1831 if (sci->sc_stage.flags & NILFS_CF_SUFREED) { 1832 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1833 sci->sc_freesegs, 1834 sci->sc_nfreesegs, 1835 NULL); 1836 WARN_ON(ret); /* do not happen */ 1837 } 1838 1839 nilfs_destroy_logs(&logs); 1840 } 1841 1842 static void nilfs_set_next_segment(struct the_nilfs *nilfs, 1843 struct nilfs_segment_buffer *segbuf) 1844 { 1845 nilfs->ns_segnum = segbuf->sb_segnum; 1846 nilfs->ns_nextnum = segbuf->sb_nextnum; 1847 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start 1848 + segbuf->sb_sum.nblocks; 1849 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq; 1850 nilfs->ns_ctime = segbuf->sb_sum.ctime; 1851 } 1852 1853 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) 1854 { 1855 struct nilfs_segment_buffer *segbuf; 1856 struct page *bd_page = NULL, *fs_page = NULL; 1857 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1858 int update_sr = false; 1859 1860 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) { 1861 struct buffer_head *bh; 1862 1863 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1864 b_assoc_buffers) { 1865 set_buffer_uptodate(bh); 1866 clear_buffer_dirty(bh); 1867 if (bh->b_page != bd_page) { 1868 if (bd_page) 1869 end_page_writeback(bd_page); 1870 bd_page = bh->b_page; 1871 } 1872 } 1873 /* 1874 * We assume that the buffers which belong to the same page 1875 * continue over the buffer list. 1876 * Under this assumption, the last BHs of pages is 1877 * identifiable by the discontinuity of bh->b_page 1878 * (page != fs_page). 1879 * 1880 * For B-tree node blocks, however, this assumption is not 1881 * guaranteed. The cleanup code of B-tree node pages needs 1882 * special care. 1883 */ 1884 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1885 b_assoc_buffers) { 1886 set_buffer_uptodate(bh); 1887 clear_buffer_dirty(bh); 1888 clear_buffer_delay(bh); 1889 clear_buffer_nilfs_volatile(bh); 1890 clear_buffer_nilfs_redirected(bh); 1891 if (bh == segbuf->sb_super_root) { 1892 if (bh->b_page != bd_page) { 1893 end_page_writeback(bd_page); 1894 bd_page = bh->b_page; 1895 } 1896 update_sr = true; 1897 break; 1898 } 1899 if (bh->b_page != fs_page) { 1900 nilfs_end_page_io(fs_page, 0); 1901 fs_page = bh->b_page; 1902 } 1903 } 1904 1905 if (!nilfs_segbuf_simplex(segbuf)) { 1906 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) { 1907 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1908 sci->sc_lseg_stime = jiffies; 1909 } 1910 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND) 1911 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1912 } 1913 } 1914 /* 1915 * Since pages may continue over multiple segment buffers, 1916 * end of the last page must be checked outside of the loop. 1917 */ 1918 if (bd_page) 1919 end_page_writeback(bd_page); 1920 1921 nilfs_end_page_io(fs_page, 0); 1922 1923 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0); 1924 1925 nilfs_drop_collected_inodes(&sci->sc_dirty_files); 1926 1927 if (nilfs_doing_gc()) 1928 nilfs_drop_collected_inodes(&sci->sc_gc_inodes); 1929 else 1930 nilfs->ns_nongc_ctime = sci->sc_seg_ctime; 1931 1932 sci->sc_nblk_inc += sci->sc_nblk_this_inc; 1933 1934 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1935 nilfs_set_next_segment(nilfs, segbuf); 1936 1937 if (update_sr) { 1938 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start, 1939 segbuf->sb_sum.seg_seq, nilfs->ns_cno++); 1940 1941 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 1942 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags); 1943 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1944 nilfs_segctor_clear_metadata_dirty(sci); 1945 } else 1946 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1947 } 1948 1949 static int nilfs_segctor_wait(struct nilfs_sc_info *sci) 1950 { 1951 int ret; 1952 1953 ret = nilfs_wait_on_logs(&sci->sc_write_logs); 1954 if (!ret) { 1955 nilfs_segctor_complete_write(sci); 1956 nilfs_destroy_logs(&sci->sc_write_logs); 1957 } 1958 return ret; 1959 } 1960 1961 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci, 1962 struct the_nilfs *nilfs) 1963 { 1964 struct nilfs_inode_info *ii, *n; 1965 struct inode *ifile = sci->sc_root->ifile; 1966 1967 spin_lock(&nilfs->ns_inode_lock); 1968 retry: 1969 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) { 1970 if (!ii->i_bh) { 1971 struct buffer_head *ibh; 1972 int err; 1973 1974 spin_unlock(&nilfs->ns_inode_lock); 1975 err = nilfs_ifile_get_inode_block( 1976 ifile, ii->vfs_inode.i_ino, &ibh); 1977 if (unlikely(err)) { 1978 nilfs_warning(sci->sc_super, __func__, 1979 "failed to get inode block.\n"); 1980 return err; 1981 } 1982 nilfs_mdt_mark_buffer_dirty(ibh); 1983 nilfs_mdt_mark_dirty(ifile); 1984 spin_lock(&nilfs->ns_inode_lock); 1985 if (likely(!ii->i_bh)) 1986 ii->i_bh = ibh; 1987 else 1988 brelse(ibh); 1989 goto retry; 1990 } 1991 1992 clear_bit(NILFS_I_QUEUED, &ii->i_state); 1993 set_bit(NILFS_I_BUSY, &ii->i_state); 1994 list_del(&ii->i_dirty); 1995 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files); 1996 } 1997 spin_unlock(&nilfs->ns_inode_lock); 1998 1999 return 0; 2000 } 2001 2002 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci, 2003 struct the_nilfs *nilfs) 2004 { 2005 struct nilfs_transaction_info *ti = current->journal_info; 2006 struct nilfs_inode_info *ii, *n; 2007 2008 spin_lock(&nilfs->ns_inode_lock); 2009 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) { 2010 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) || 2011 test_bit(NILFS_I_DIRTY, &ii->i_state)) 2012 continue; 2013 2014 clear_bit(NILFS_I_BUSY, &ii->i_state); 2015 brelse(ii->i_bh); 2016 ii->i_bh = NULL; 2017 list_del(&ii->i_dirty); 2018 list_add_tail(&ii->i_dirty, &ti->ti_garbage); 2019 } 2020 spin_unlock(&nilfs->ns_inode_lock); 2021 } 2022 2023 /* 2024 * Main procedure of segment constructor 2025 */ 2026 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) 2027 { 2028 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2029 struct page *failed_page; 2030 int err; 2031 2032 sci->sc_stage.scnt = NILFS_ST_INIT; 2033 sci->sc_cno = nilfs->ns_cno; 2034 2035 err = nilfs_segctor_collect_dirty_files(sci, nilfs); 2036 if (unlikely(err)) 2037 goto out; 2038 2039 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 2040 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 2041 2042 if (nilfs_segctor_clean(sci)) 2043 goto out; 2044 2045 do { 2046 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK; 2047 2048 err = nilfs_segctor_begin_construction(sci, nilfs); 2049 if (unlikely(err)) 2050 goto out; 2051 2052 /* Update time stamp */ 2053 sci->sc_seg_ctime = get_seconds(); 2054 2055 err = nilfs_segctor_collect(sci, nilfs, mode); 2056 if (unlikely(err)) 2057 goto failed; 2058 2059 /* Avoid empty segment */ 2060 if (sci->sc_stage.scnt == NILFS_ST_DONE && 2061 nilfs_segbuf_empty(sci->sc_curseg)) { 2062 nilfs_segctor_abort_construction(sci, nilfs, 1); 2063 goto out; 2064 } 2065 2066 err = nilfs_segctor_assign(sci, mode); 2067 if (unlikely(err)) 2068 goto failed; 2069 2070 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 2071 nilfs_segctor_fill_in_file_bmap(sci); 2072 2073 if (mode == SC_LSEG_SR && 2074 sci->sc_stage.scnt >= NILFS_ST_CPFILE) { 2075 err = nilfs_segctor_fill_in_checkpoint(sci); 2076 if (unlikely(err)) 2077 goto failed_to_write; 2078 2079 nilfs_segctor_fill_in_super_root(sci, nilfs); 2080 } 2081 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile); 2082 2083 /* Write partial segments */ 2084 err = nilfs_segctor_prepare_write(sci, &failed_page); 2085 if (err) { 2086 nilfs_abort_logs(&sci->sc_segbufs, failed_page, err); 2087 goto failed_to_write; 2088 } 2089 2090 nilfs_add_checksums_on_logs(&sci->sc_segbufs, 2091 nilfs->ns_crc_seed); 2092 2093 err = nilfs_segctor_write(sci, nilfs); 2094 if (unlikely(err)) 2095 goto failed_to_write; 2096 2097 if (sci->sc_stage.scnt == NILFS_ST_DONE || 2098 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) { 2099 /* 2100 * At this point, we avoid double buffering 2101 * for blocksize < pagesize because page dirty 2102 * flag is turned off during write and dirty 2103 * buffers are not properly collected for 2104 * pages crossing over segments. 2105 */ 2106 err = nilfs_segctor_wait(sci); 2107 if (err) 2108 goto failed_to_write; 2109 } 2110 } while (sci->sc_stage.scnt != NILFS_ST_DONE); 2111 2112 out: 2113 nilfs_segctor_drop_written_files(sci, nilfs); 2114 return err; 2115 2116 failed_to_write: 2117 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 2118 nilfs_redirty_inodes(&sci->sc_dirty_files); 2119 2120 failed: 2121 if (nilfs_doing_gc()) 2122 nilfs_redirty_inodes(&sci->sc_gc_inodes); 2123 nilfs_segctor_abort_construction(sci, nilfs, err); 2124 goto out; 2125 } 2126 2127 /** 2128 * nilfs_segctor_start_timer - set timer of background write 2129 * @sci: nilfs_sc_info 2130 * 2131 * If the timer has already been set, it ignores the new request. 2132 * This function MUST be called within a section locking the segment 2133 * semaphore. 2134 */ 2135 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci) 2136 { 2137 spin_lock(&sci->sc_state_lock); 2138 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) { 2139 sci->sc_timer.expires = jiffies + sci->sc_interval; 2140 add_timer(&sci->sc_timer); 2141 sci->sc_state |= NILFS_SEGCTOR_COMMIT; 2142 } 2143 spin_unlock(&sci->sc_state_lock); 2144 } 2145 2146 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn) 2147 { 2148 spin_lock(&sci->sc_state_lock); 2149 if (!(sci->sc_flush_request & (1 << bn))) { 2150 unsigned long prev_req = sci->sc_flush_request; 2151 2152 sci->sc_flush_request |= (1 << bn); 2153 if (!prev_req) 2154 wake_up(&sci->sc_wait_daemon); 2155 } 2156 spin_unlock(&sci->sc_state_lock); 2157 } 2158 2159 /** 2160 * nilfs_flush_segment - trigger a segment construction for resource control 2161 * @sb: super block 2162 * @ino: inode number of the file to be flushed out. 2163 */ 2164 void nilfs_flush_segment(struct super_block *sb, ino_t ino) 2165 { 2166 struct the_nilfs *nilfs = sb->s_fs_info; 2167 struct nilfs_sc_info *sci = nilfs->ns_writer; 2168 2169 if (!sci || nilfs_doing_construction()) 2170 return; 2171 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0); 2172 /* assign bit 0 to data files */ 2173 } 2174 2175 struct nilfs_segctor_wait_request { 2176 wait_queue_t wq; 2177 __u32 seq; 2178 int err; 2179 atomic_t done; 2180 }; 2181 2182 static int nilfs_segctor_sync(struct nilfs_sc_info *sci) 2183 { 2184 struct nilfs_segctor_wait_request wait_req; 2185 int err = 0; 2186 2187 spin_lock(&sci->sc_state_lock); 2188 init_wait(&wait_req.wq); 2189 wait_req.err = 0; 2190 atomic_set(&wait_req.done, 0); 2191 wait_req.seq = ++sci->sc_seq_request; 2192 spin_unlock(&sci->sc_state_lock); 2193 2194 init_waitqueue_entry(&wait_req.wq, current); 2195 add_wait_queue(&sci->sc_wait_request, &wait_req.wq); 2196 set_current_state(TASK_INTERRUPTIBLE); 2197 wake_up(&sci->sc_wait_daemon); 2198 2199 for (;;) { 2200 if (atomic_read(&wait_req.done)) { 2201 err = wait_req.err; 2202 break; 2203 } 2204 if (!signal_pending(current)) { 2205 schedule(); 2206 continue; 2207 } 2208 err = -ERESTARTSYS; 2209 break; 2210 } 2211 finish_wait(&sci->sc_wait_request, &wait_req.wq); 2212 return err; 2213 } 2214 2215 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err) 2216 { 2217 struct nilfs_segctor_wait_request *wrq, *n; 2218 unsigned long flags; 2219 2220 spin_lock_irqsave(&sci->sc_wait_request.lock, flags); 2221 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list, 2222 wq.task_list) { 2223 if (!atomic_read(&wrq->done) && 2224 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) { 2225 wrq->err = err; 2226 atomic_set(&wrq->done, 1); 2227 } 2228 if (atomic_read(&wrq->done)) { 2229 wrq->wq.func(&wrq->wq, 2230 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 2231 0, NULL); 2232 } 2233 } 2234 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags); 2235 } 2236 2237 /** 2238 * nilfs_construct_segment - construct a logical segment 2239 * @sb: super block 2240 * 2241 * Return Value: On success, 0 is retured. On errors, one of the following 2242 * negative error code is returned. 2243 * 2244 * %-EROFS - Read only filesystem. 2245 * 2246 * %-EIO - I/O error 2247 * 2248 * %-ENOSPC - No space left on device (only in a panic state). 2249 * 2250 * %-ERESTARTSYS - Interrupted. 2251 * 2252 * %-ENOMEM - Insufficient memory available. 2253 */ 2254 int nilfs_construct_segment(struct super_block *sb) 2255 { 2256 struct the_nilfs *nilfs = sb->s_fs_info; 2257 struct nilfs_sc_info *sci = nilfs->ns_writer; 2258 struct nilfs_transaction_info *ti; 2259 int err; 2260 2261 if (!sci) 2262 return -EROFS; 2263 2264 /* A call inside transactions causes a deadlock. */ 2265 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC); 2266 2267 err = nilfs_segctor_sync(sci); 2268 return err; 2269 } 2270 2271 /** 2272 * nilfs_construct_dsync_segment - construct a data-only logical segment 2273 * @sb: super block 2274 * @inode: inode whose data blocks should be written out 2275 * @start: start byte offset 2276 * @end: end byte offset (inclusive) 2277 * 2278 * Return Value: On success, 0 is retured. On errors, one of the following 2279 * negative error code is returned. 2280 * 2281 * %-EROFS - Read only filesystem. 2282 * 2283 * %-EIO - I/O error 2284 * 2285 * %-ENOSPC - No space left on device (only in a panic state). 2286 * 2287 * %-ERESTARTSYS - Interrupted. 2288 * 2289 * %-ENOMEM - Insufficient memory available. 2290 */ 2291 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode, 2292 loff_t start, loff_t end) 2293 { 2294 struct the_nilfs *nilfs = sb->s_fs_info; 2295 struct nilfs_sc_info *sci = nilfs->ns_writer; 2296 struct nilfs_inode_info *ii; 2297 struct nilfs_transaction_info ti; 2298 int err = 0; 2299 2300 if (!sci) 2301 return -EROFS; 2302 2303 nilfs_transaction_lock(sb, &ti, 0); 2304 2305 ii = NILFS_I(inode); 2306 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) || 2307 nilfs_test_opt(nilfs, STRICT_ORDER) || 2308 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2309 nilfs_discontinued(nilfs)) { 2310 nilfs_transaction_unlock(sb); 2311 err = nilfs_segctor_sync(sci); 2312 return err; 2313 } 2314 2315 spin_lock(&nilfs->ns_inode_lock); 2316 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) && 2317 !test_bit(NILFS_I_BUSY, &ii->i_state)) { 2318 spin_unlock(&nilfs->ns_inode_lock); 2319 nilfs_transaction_unlock(sb); 2320 return 0; 2321 } 2322 spin_unlock(&nilfs->ns_inode_lock); 2323 sci->sc_dsync_inode = ii; 2324 sci->sc_dsync_start = start; 2325 sci->sc_dsync_end = end; 2326 2327 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC); 2328 2329 nilfs_transaction_unlock(sb); 2330 return err; 2331 } 2332 2333 #define FLUSH_FILE_BIT (0x1) /* data file only */ 2334 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */ 2335 2336 /** 2337 * nilfs_segctor_accept - record accepted sequence count of log-write requests 2338 * @sci: segment constructor object 2339 */ 2340 static void nilfs_segctor_accept(struct nilfs_sc_info *sci) 2341 { 2342 spin_lock(&sci->sc_state_lock); 2343 sci->sc_seq_accepted = sci->sc_seq_request; 2344 spin_unlock(&sci->sc_state_lock); 2345 del_timer_sync(&sci->sc_timer); 2346 } 2347 2348 /** 2349 * nilfs_segctor_notify - notify the result of request to caller threads 2350 * @sci: segment constructor object 2351 * @mode: mode of log forming 2352 * @err: error code to be notified 2353 */ 2354 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err) 2355 { 2356 /* Clear requests (even when the construction failed) */ 2357 spin_lock(&sci->sc_state_lock); 2358 2359 if (mode == SC_LSEG_SR) { 2360 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT; 2361 sci->sc_seq_done = sci->sc_seq_accepted; 2362 nilfs_segctor_wakeup(sci, err); 2363 sci->sc_flush_request = 0; 2364 } else { 2365 if (mode == SC_FLUSH_FILE) 2366 sci->sc_flush_request &= ~FLUSH_FILE_BIT; 2367 else if (mode == SC_FLUSH_DAT) 2368 sci->sc_flush_request &= ~FLUSH_DAT_BIT; 2369 2370 /* re-enable timer if checkpoint creation was not done */ 2371 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2372 time_before(jiffies, sci->sc_timer.expires)) 2373 add_timer(&sci->sc_timer); 2374 } 2375 spin_unlock(&sci->sc_state_lock); 2376 } 2377 2378 /** 2379 * nilfs_segctor_construct - form logs and write them to disk 2380 * @sci: segment constructor object 2381 * @mode: mode of log forming 2382 */ 2383 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode) 2384 { 2385 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2386 struct nilfs_super_block **sbp; 2387 int err = 0; 2388 2389 nilfs_segctor_accept(sci); 2390 2391 if (nilfs_discontinued(nilfs)) 2392 mode = SC_LSEG_SR; 2393 if (!nilfs_segctor_confirm(sci)) 2394 err = nilfs_segctor_do_construct(sci, mode); 2395 2396 if (likely(!err)) { 2397 if (mode != SC_FLUSH_DAT) 2398 atomic_set(&nilfs->ns_ndirtyblks, 0); 2399 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) && 2400 nilfs_discontinued(nilfs)) { 2401 down_write(&nilfs->ns_sem); 2402 err = -EIO; 2403 sbp = nilfs_prepare_super(sci->sc_super, 2404 nilfs_sb_will_flip(nilfs)); 2405 if (likely(sbp)) { 2406 nilfs_set_log_cursor(sbp[0], nilfs); 2407 err = nilfs_commit_super(sci->sc_super, 2408 NILFS_SB_COMMIT); 2409 } 2410 up_write(&nilfs->ns_sem); 2411 } 2412 } 2413 2414 nilfs_segctor_notify(sci, mode, err); 2415 return err; 2416 } 2417 2418 static void nilfs_construction_timeout(unsigned long data) 2419 { 2420 struct task_struct *p = (struct task_struct *)data; 2421 wake_up_process(p); 2422 } 2423 2424 static void 2425 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head) 2426 { 2427 struct nilfs_inode_info *ii, *n; 2428 2429 list_for_each_entry_safe(ii, n, head, i_dirty) { 2430 if (!test_bit(NILFS_I_UPDATED, &ii->i_state)) 2431 continue; 2432 list_del_init(&ii->i_dirty); 2433 iput(&ii->vfs_inode); 2434 } 2435 } 2436 2437 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv, 2438 void **kbufs) 2439 { 2440 struct the_nilfs *nilfs = sb->s_fs_info; 2441 struct nilfs_sc_info *sci = nilfs->ns_writer; 2442 struct nilfs_transaction_info ti; 2443 int err; 2444 2445 if (unlikely(!sci)) 2446 return -EROFS; 2447 2448 nilfs_transaction_lock(sb, &ti, 1); 2449 2450 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat); 2451 if (unlikely(err)) 2452 goto out_unlock; 2453 2454 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs); 2455 if (unlikely(err)) { 2456 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat); 2457 goto out_unlock; 2458 } 2459 2460 sci->sc_freesegs = kbufs[4]; 2461 sci->sc_nfreesegs = argv[4].v_nmembs; 2462 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes); 2463 2464 for (;;) { 2465 err = nilfs_segctor_construct(sci, SC_LSEG_SR); 2466 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes); 2467 2468 if (likely(!err)) 2469 break; 2470 2471 nilfs_warning(sb, __func__, 2472 "segment construction failed. (err=%d)", err); 2473 set_current_state(TASK_INTERRUPTIBLE); 2474 schedule_timeout(sci->sc_interval); 2475 } 2476 if (nilfs_test_opt(nilfs, DISCARD)) { 2477 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs, 2478 sci->sc_nfreesegs); 2479 if (ret) { 2480 printk(KERN_WARNING 2481 "NILFS warning: error %d on discard request, " 2482 "turning discards off for the device\n", ret); 2483 nilfs_clear_opt(nilfs, DISCARD); 2484 } 2485 } 2486 2487 out_unlock: 2488 sci->sc_freesegs = NULL; 2489 sci->sc_nfreesegs = 0; 2490 nilfs_mdt_clear_shadow_map(nilfs->ns_dat); 2491 nilfs_transaction_unlock(sb); 2492 return err; 2493 } 2494 2495 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode) 2496 { 2497 struct nilfs_transaction_info ti; 2498 2499 nilfs_transaction_lock(sci->sc_super, &ti, 0); 2500 nilfs_segctor_construct(sci, mode); 2501 2502 /* 2503 * Unclosed segment should be retried. We do this using sc_timer. 2504 * Timeout of sc_timer will invoke complete construction which leads 2505 * to close the current logical segment. 2506 */ 2507 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) 2508 nilfs_segctor_start_timer(sci); 2509 2510 nilfs_transaction_unlock(sci->sc_super); 2511 } 2512 2513 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci) 2514 { 2515 int mode = 0; 2516 int err; 2517 2518 spin_lock(&sci->sc_state_lock); 2519 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ? 2520 SC_FLUSH_DAT : SC_FLUSH_FILE; 2521 spin_unlock(&sci->sc_state_lock); 2522 2523 if (mode) { 2524 err = nilfs_segctor_do_construct(sci, mode); 2525 2526 spin_lock(&sci->sc_state_lock); 2527 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ? 2528 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT; 2529 spin_unlock(&sci->sc_state_lock); 2530 } 2531 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 2532 } 2533 2534 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci) 2535 { 2536 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2537 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) { 2538 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT)) 2539 return SC_FLUSH_FILE; 2540 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT)) 2541 return SC_FLUSH_DAT; 2542 } 2543 return SC_LSEG_SR; 2544 } 2545 2546 /** 2547 * nilfs_segctor_thread - main loop of the segment constructor thread. 2548 * @arg: pointer to a struct nilfs_sc_info. 2549 * 2550 * nilfs_segctor_thread() initializes a timer and serves as a daemon 2551 * to execute segment constructions. 2552 */ 2553 static int nilfs_segctor_thread(void *arg) 2554 { 2555 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg; 2556 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2557 int timeout = 0; 2558 2559 sci->sc_timer.data = (unsigned long)current; 2560 sci->sc_timer.function = nilfs_construction_timeout; 2561 2562 /* start sync. */ 2563 sci->sc_task = current; 2564 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */ 2565 printk(KERN_INFO 2566 "segctord starting. Construction interval = %lu seconds, " 2567 "CP frequency < %lu seconds\n", 2568 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ); 2569 2570 spin_lock(&sci->sc_state_lock); 2571 loop: 2572 for (;;) { 2573 int mode; 2574 2575 if (sci->sc_state & NILFS_SEGCTOR_QUIT) 2576 goto end_thread; 2577 2578 if (timeout || sci->sc_seq_request != sci->sc_seq_done) 2579 mode = SC_LSEG_SR; 2580 else if (!sci->sc_flush_request) 2581 break; 2582 else 2583 mode = nilfs_segctor_flush_mode(sci); 2584 2585 spin_unlock(&sci->sc_state_lock); 2586 nilfs_segctor_thread_construct(sci, mode); 2587 spin_lock(&sci->sc_state_lock); 2588 timeout = 0; 2589 } 2590 2591 2592 if (freezing(current)) { 2593 spin_unlock(&sci->sc_state_lock); 2594 refrigerator(); 2595 spin_lock(&sci->sc_state_lock); 2596 } else { 2597 DEFINE_WAIT(wait); 2598 int should_sleep = 1; 2599 2600 prepare_to_wait(&sci->sc_wait_daemon, &wait, 2601 TASK_INTERRUPTIBLE); 2602 2603 if (sci->sc_seq_request != sci->sc_seq_done) 2604 should_sleep = 0; 2605 else if (sci->sc_flush_request) 2606 should_sleep = 0; 2607 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT) 2608 should_sleep = time_before(jiffies, 2609 sci->sc_timer.expires); 2610 2611 if (should_sleep) { 2612 spin_unlock(&sci->sc_state_lock); 2613 schedule(); 2614 spin_lock(&sci->sc_state_lock); 2615 } 2616 finish_wait(&sci->sc_wait_daemon, &wait); 2617 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2618 time_after_eq(jiffies, sci->sc_timer.expires)); 2619 2620 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs)) 2621 set_nilfs_discontinued(nilfs); 2622 } 2623 goto loop; 2624 2625 end_thread: 2626 spin_unlock(&sci->sc_state_lock); 2627 2628 /* end sync. */ 2629 sci->sc_task = NULL; 2630 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */ 2631 return 0; 2632 } 2633 2634 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci) 2635 { 2636 struct task_struct *t; 2637 2638 t = kthread_run(nilfs_segctor_thread, sci, "segctord"); 2639 if (IS_ERR(t)) { 2640 int err = PTR_ERR(t); 2641 2642 printk(KERN_ERR "NILFS: error %d creating segctord thread\n", 2643 err); 2644 return err; 2645 } 2646 wait_event(sci->sc_wait_task, sci->sc_task != NULL); 2647 return 0; 2648 } 2649 2650 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci) 2651 __acquires(&sci->sc_state_lock) 2652 __releases(&sci->sc_state_lock) 2653 { 2654 sci->sc_state |= NILFS_SEGCTOR_QUIT; 2655 2656 while (sci->sc_task) { 2657 wake_up(&sci->sc_wait_daemon); 2658 spin_unlock(&sci->sc_state_lock); 2659 wait_event(sci->sc_wait_task, sci->sc_task == NULL); 2660 spin_lock(&sci->sc_state_lock); 2661 } 2662 } 2663 2664 /* 2665 * Setup & clean-up functions 2666 */ 2667 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb, 2668 struct nilfs_root *root) 2669 { 2670 struct the_nilfs *nilfs = sb->s_fs_info; 2671 struct nilfs_sc_info *sci; 2672 2673 sci = kzalloc(sizeof(*sci), GFP_KERNEL); 2674 if (!sci) 2675 return NULL; 2676 2677 sci->sc_super = sb; 2678 2679 nilfs_get_root(root); 2680 sci->sc_root = root; 2681 2682 init_waitqueue_head(&sci->sc_wait_request); 2683 init_waitqueue_head(&sci->sc_wait_daemon); 2684 init_waitqueue_head(&sci->sc_wait_task); 2685 spin_lock_init(&sci->sc_state_lock); 2686 INIT_LIST_HEAD(&sci->sc_dirty_files); 2687 INIT_LIST_HEAD(&sci->sc_segbufs); 2688 INIT_LIST_HEAD(&sci->sc_write_logs); 2689 INIT_LIST_HEAD(&sci->sc_gc_inodes); 2690 INIT_LIST_HEAD(&sci->sc_copied_buffers); 2691 init_timer(&sci->sc_timer); 2692 2693 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT; 2694 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ; 2695 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK; 2696 2697 if (nilfs->ns_interval) 2698 sci->sc_interval = nilfs->ns_interval; 2699 if (nilfs->ns_watermark) 2700 sci->sc_watermark = nilfs->ns_watermark; 2701 return sci; 2702 } 2703 2704 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci) 2705 { 2706 int ret, retrycount = NILFS_SC_CLEANUP_RETRY; 2707 2708 /* The segctord thread was stopped and its timer was removed. 2709 But some tasks remain. */ 2710 do { 2711 struct nilfs_transaction_info ti; 2712 2713 nilfs_transaction_lock(sci->sc_super, &ti, 0); 2714 ret = nilfs_segctor_construct(sci, SC_LSEG_SR); 2715 nilfs_transaction_unlock(sci->sc_super); 2716 2717 } while (ret && retrycount-- > 0); 2718 } 2719 2720 /** 2721 * nilfs_segctor_destroy - destroy the segment constructor. 2722 * @sci: nilfs_sc_info 2723 * 2724 * nilfs_segctor_destroy() kills the segctord thread and frees 2725 * the nilfs_sc_info struct. 2726 * Caller must hold the segment semaphore. 2727 */ 2728 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci) 2729 { 2730 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2731 int flag; 2732 2733 up_write(&nilfs->ns_segctor_sem); 2734 2735 spin_lock(&sci->sc_state_lock); 2736 nilfs_segctor_kill_thread(sci); 2737 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request 2738 || sci->sc_seq_request != sci->sc_seq_done); 2739 spin_unlock(&sci->sc_state_lock); 2740 2741 if (flag || !nilfs_segctor_confirm(sci)) 2742 nilfs_segctor_write_out(sci); 2743 2744 WARN_ON(!list_empty(&sci->sc_copied_buffers)); 2745 2746 if (!list_empty(&sci->sc_dirty_files)) { 2747 nilfs_warning(sci->sc_super, __func__, 2748 "dirty file(s) after the final construction\n"); 2749 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1); 2750 } 2751 2752 WARN_ON(!list_empty(&sci->sc_segbufs)); 2753 WARN_ON(!list_empty(&sci->sc_write_logs)); 2754 2755 nilfs_put_root(sci->sc_root); 2756 2757 down_write(&nilfs->ns_segctor_sem); 2758 2759 del_timer_sync(&sci->sc_timer); 2760 kfree(sci); 2761 } 2762 2763 /** 2764 * nilfs_attach_log_writer - attach log writer 2765 * @sb: super block instance 2766 * @root: root object of the current filesystem tree 2767 * 2768 * This allocates a log writer object, initializes it, and starts the 2769 * log writer. 2770 * 2771 * Return Value: On success, 0 is returned. On error, one of the following 2772 * negative error code is returned. 2773 * 2774 * %-ENOMEM - Insufficient memory available. 2775 */ 2776 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root) 2777 { 2778 struct the_nilfs *nilfs = sb->s_fs_info; 2779 int err; 2780 2781 if (nilfs->ns_writer) { 2782 /* 2783 * This happens if the filesystem was remounted 2784 * read/write after nilfs_error degenerated it into a 2785 * read-only mount. 2786 */ 2787 nilfs_detach_log_writer(sb); 2788 } 2789 2790 nilfs->ns_writer = nilfs_segctor_new(sb, root); 2791 if (!nilfs->ns_writer) 2792 return -ENOMEM; 2793 2794 err = nilfs_segctor_start_thread(nilfs->ns_writer); 2795 if (err) { 2796 kfree(nilfs->ns_writer); 2797 nilfs->ns_writer = NULL; 2798 } 2799 return err; 2800 } 2801 2802 /** 2803 * nilfs_detach_log_writer - destroy log writer 2804 * @sb: super block instance 2805 * 2806 * This kills log writer daemon, frees the log writer object, and 2807 * destroys list of dirty files. 2808 */ 2809 void nilfs_detach_log_writer(struct super_block *sb) 2810 { 2811 struct the_nilfs *nilfs = sb->s_fs_info; 2812 LIST_HEAD(garbage_list); 2813 2814 down_write(&nilfs->ns_segctor_sem); 2815 if (nilfs->ns_writer) { 2816 nilfs_segctor_destroy(nilfs->ns_writer); 2817 nilfs->ns_writer = NULL; 2818 } 2819 2820 /* Force to free the list of dirty files */ 2821 spin_lock(&nilfs->ns_inode_lock); 2822 if (!list_empty(&nilfs->ns_dirty_files)) { 2823 list_splice_init(&nilfs->ns_dirty_files, &garbage_list); 2824 nilfs_warning(sb, __func__, 2825 "Hit dirty file after stopped log writer\n"); 2826 } 2827 spin_unlock(&nilfs->ns_inode_lock); 2828 up_write(&nilfs->ns_segctor_sem); 2829 2830 nilfs_dispose_list(nilfs, &garbage_list, 1); 2831 } 2832