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 nilfs_sb_info *, struct list_head *, 108 int); 109 110 #define nilfs_cnt32_gt(a, b) \ 111 (typecheck(__u32, a) && typecheck(__u32, b) && \ 112 ((__s32)(b) - (__s32)(a) < 0)) 113 #define nilfs_cnt32_ge(a, b) \ 114 (typecheck(__u32, a) && typecheck(__u32, b) && \ 115 ((__s32)(a) - (__s32)(b) >= 0)) 116 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a) 117 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a) 118 119 static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti) 120 { 121 struct nilfs_transaction_info *cur_ti = current->journal_info; 122 void *save = NULL; 123 124 if (cur_ti) { 125 if (cur_ti->ti_magic == NILFS_TI_MAGIC) 126 return ++cur_ti->ti_count; 127 else { 128 /* 129 * If journal_info field is occupied by other FS, 130 * it is saved and will be restored on 131 * nilfs_transaction_commit(). 132 */ 133 printk(KERN_WARNING 134 "NILFS warning: journal info from a different " 135 "FS\n"); 136 save = current->journal_info; 137 } 138 } 139 if (!ti) { 140 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS); 141 if (!ti) 142 return -ENOMEM; 143 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC; 144 } else { 145 ti->ti_flags = 0; 146 } 147 ti->ti_count = 0; 148 ti->ti_save = save; 149 ti->ti_magic = NILFS_TI_MAGIC; 150 current->journal_info = ti; 151 return 0; 152 } 153 154 /** 155 * nilfs_transaction_begin - start indivisible file operations. 156 * @sb: super block 157 * @ti: nilfs_transaction_info 158 * @vacancy_check: flags for vacancy rate checks 159 * 160 * nilfs_transaction_begin() acquires a reader/writer semaphore, called 161 * the segment semaphore, to make a segment construction and write tasks 162 * exclusive. The function is used with nilfs_transaction_commit() in pairs. 163 * The region enclosed by these two functions can be nested. To avoid a 164 * deadlock, the semaphore is only acquired or released in the outermost call. 165 * 166 * This function allocates a nilfs_transaction_info struct to keep context 167 * information on it. It is initialized and hooked onto the current task in 168 * the outermost call. If a pre-allocated struct is given to @ti, it is used 169 * instead; otherwise a new struct is assigned from a slab. 170 * 171 * When @vacancy_check flag is set, this function will check the amount of 172 * free space, and will wait for the GC to reclaim disk space if low capacity. 173 * 174 * Return Value: On success, 0 is returned. On error, one of the following 175 * negative error code is returned. 176 * 177 * %-ENOMEM - Insufficient memory available. 178 * 179 * %-ENOSPC - No space left on device 180 */ 181 int nilfs_transaction_begin(struct super_block *sb, 182 struct nilfs_transaction_info *ti, 183 int vacancy_check) 184 { 185 struct nilfs_sb_info *sbi; 186 struct the_nilfs *nilfs; 187 int ret = nilfs_prepare_segment_lock(ti); 188 189 if (unlikely(ret < 0)) 190 return ret; 191 if (ret > 0) 192 return 0; 193 194 vfs_check_frozen(sb, SB_FREEZE_WRITE); 195 196 sbi = NILFS_SB(sb); 197 nilfs = sbi->s_nilfs; 198 down_read(&nilfs->ns_segctor_sem); 199 if (vacancy_check && nilfs_near_disk_full(nilfs)) { 200 up_read(&nilfs->ns_segctor_sem); 201 ret = -ENOSPC; 202 goto failed; 203 } 204 return 0; 205 206 failed: 207 ti = current->journal_info; 208 current->journal_info = ti->ti_save; 209 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 210 kmem_cache_free(nilfs_transaction_cachep, ti); 211 return ret; 212 } 213 214 /** 215 * nilfs_transaction_commit - commit indivisible file operations. 216 * @sb: super block 217 * 218 * nilfs_transaction_commit() releases the read semaphore which is 219 * acquired by nilfs_transaction_begin(). This is only performed 220 * in outermost call of this function. If a commit flag is set, 221 * nilfs_transaction_commit() sets a timer to start the segment 222 * constructor. If a sync flag is set, it starts construction 223 * directly. 224 */ 225 int nilfs_transaction_commit(struct super_block *sb) 226 { 227 struct nilfs_transaction_info *ti = current->journal_info; 228 struct nilfs_sb_info *sbi; 229 struct nilfs_sc_info *sci; 230 int err = 0; 231 232 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 233 ti->ti_flags |= NILFS_TI_COMMIT; 234 if (ti->ti_count > 0) { 235 ti->ti_count--; 236 return 0; 237 } 238 sbi = NILFS_SB(sb); 239 sci = NILFS_SC(sbi); 240 if (sci != NULL) { 241 if (ti->ti_flags & NILFS_TI_COMMIT) 242 nilfs_segctor_start_timer(sci); 243 if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) > 244 sci->sc_watermark) 245 nilfs_segctor_do_flush(sci, 0); 246 } 247 up_read(&sbi->s_nilfs->ns_segctor_sem); 248 current->journal_info = ti->ti_save; 249 250 if (ti->ti_flags & NILFS_TI_SYNC) 251 err = nilfs_construct_segment(sb); 252 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 253 kmem_cache_free(nilfs_transaction_cachep, ti); 254 return err; 255 } 256 257 void nilfs_transaction_abort(struct super_block *sb) 258 { 259 struct nilfs_transaction_info *ti = current->journal_info; 260 261 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 262 if (ti->ti_count > 0) { 263 ti->ti_count--; 264 return; 265 } 266 up_read(&NILFS_SB(sb)->s_nilfs->ns_segctor_sem); 267 268 current->journal_info = ti->ti_save; 269 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 270 kmem_cache_free(nilfs_transaction_cachep, ti); 271 } 272 273 void nilfs_relax_pressure_in_lock(struct super_block *sb) 274 { 275 struct nilfs_sb_info *sbi = NILFS_SB(sb); 276 struct nilfs_sc_info *sci = NILFS_SC(sbi); 277 struct the_nilfs *nilfs = sbi->s_nilfs; 278 279 if (!sci || !sci->sc_flush_request) 280 return; 281 282 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 283 up_read(&nilfs->ns_segctor_sem); 284 285 down_write(&nilfs->ns_segctor_sem); 286 if (sci->sc_flush_request && 287 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) { 288 struct nilfs_transaction_info *ti = current->journal_info; 289 290 ti->ti_flags |= NILFS_TI_WRITER; 291 nilfs_segctor_do_immediate_flush(sci); 292 ti->ti_flags &= ~NILFS_TI_WRITER; 293 } 294 downgrade_write(&nilfs->ns_segctor_sem); 295 } 296 297 static void nilfs_transaction_lock(struct nilfs_sb_info *sbi, 298 struct nilfs_transaction_info *ti, 299 int gcflag) 300 { 301 struct nilfs_transaction_info *cur_ti = current->journal_info; 302 303 WARN_ON(cur_ti); 304 ti->ti_flags = NILFS_TI_WRITER; 305 ti->ti_count = 0; 306 ti->ti_save = cur_ti; 307 ti->ti_magic = NILFS_TI_MAGIC; 308 INIT_LIST_HEAD(&ti->ti_garbage); 309 current->journal_info = ti; 310 311 for (;;) { 312 down_write(&sbi->s_nilfs->ns_segctor_sem); 313 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags)) 314 break; 315 316 nilfs_segctor_do_immediate_flush(NILFS_SC(sbi)); 317 318 up_write(&sbi->s_nilfs->ns_segctor_sem); 319 yield(); 320 } 321 if (gcflag) 322 ti->ti_flags |= NILFS_TI_GC; 323 } 324 325 static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi) 326 { 327 struct nilfs_transaction_info *ti = current->journal_info; 328 329 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 330 BUG_ON(ti->ti_count > 0); 331 332 up_write(&sbi->s_nilfs->ns_segctor_sem); 333 current->journal_info = ti->ti_save; 334 if (!list_empty(&ti->ti_garbage)) 335 nilfs_dispose_list(sbi, &ti->ti_garbage, 0); 336 } 337 338 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci, 339 struct nilfs_segsum_pointer *ssp, 340 unsigned bytes) 341 { 342 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 343 unsigned blocksize = sci->sc_super->s_blocksize; 344 void *p; 345 346 if (unlikely(ssp->offset + bytes > blocksize)) { 347 ssp->offset = 0; 348 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh, 349 &segbuf->sb_segsum_buffers)); 350 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh); 351 } 352 p = ssp->bh->b_data + ssp->offset; 353 ssp->offset += bytes; 354 return p; 355 } 356 357 /** 358 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer 359 * @sci: nilfs_sc_info 360 */ 361 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci) 362 { 363 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 364 struct buffer_head *sumbh; 365 unsigned sumbytes; 366 unsigned flags = 0; 367 int err; 368 369 if (nilfs_doing_gc()) 370 flags = NILFS_SS_GC; 371 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno); 372 if (unlikely(err)) 373 return err; 374 375 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); 376 sumbytes = segbuf->sb_sum.sumbytes; 377 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes; 378 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes; 379 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; 380 return 0; 381 } 382 383 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci) 384 { 385 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; 386 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs)) 387 return -E2BIG; /* The current segment is filled up 388 (internal code) */ 389 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg); 390 return nilfs_segctor_reset_segment_buffer(sci); 391 } 392 393 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci) 394 { 395 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 396 int err; 397 398 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) { 399 err = nilfs_segctor_feed_segment(sci); 400 if (err) 401 return err; 402 segbuf = sci->sc_curseg; 403 } 404 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root); 405 if (likely(!err)) 406 segbuf->sb_sum.flags |= NILFS_SS_SR; 407 return err; 408 } 409 410 /* 411 * Functions for making segment summary and payloads 412 */ 413 static int nilfs_segctor_segsum_block_required( 414 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp, 415 unsigned binfo_size) 416 { 417 unsigned blocksize = sci->sc_super->s_blocksize; 418 /* Size of finfo and binfo is enough small against blocksize */ 419 420 return ssp->offset + binfo_size + 421 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) > 422 blocksize; 423 } 424 425 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci, 426 struct inode *inode) 427 { 428 sci->sc_curseg->sb_sum.nfinfo++; 429 sci->sc_binfo_ptr = sci->sc_finfo_ptr; 430 nilfs_segctor_map_segsum_entry( 431 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo)); 432 433 if (NILFS_I(inode)->i_root && 434 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 435 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 436 /* skip finfo */ 437 } 438 439 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci, 440 struct inode *inode) 441 { 442 struct nilfs_finfo *finfo; 443 struct nilfs_inode_info *ii; 444 struct nilfs_segment_buffer *segbuf; 445 __u64 cno; 446 447 if (sci->sc_blk_cnt == 0) 448 return; 449 450 ii = NILFS_I(inode); 451 452 if (test_bit(NILFS_I_GCINODE, &ii->i_state)) 453 cno = ii->i_cno; 454 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) 455 cno = 0; 456 else 457 cno = sci->sc_cno; 458 459 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr, 460 sizeof(*finfo)); 461 finfo->fi_ino = cpu_to_le64(inode->i_ino); 462 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt); 463 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt); 464 finfo->fi_cno = cpu_to_le64(cno); 465 466 segbuf = sci->sc_curseg; 467 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset + 468 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1); 469 sci->sc_finfo_ptr = sci->sc_binfo_ptr; 470 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; 471 } 472 473 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci, 474 struct buffer_head *bh, 475 struct inode *inode, 476 unsigned binfo_size) 477 { 478 struct nilfs_segment_buffer *segbuf; 479 int required, err = 0; 480 481 retry: 482 segbuf = sci->sc_curseg; 483 required = nilfs_segctor_segsum_block_required( 484 sci, &sci->sc_binfo_ptr, binfo_size); 485 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) { 486 nilfs_segctor_end_finfo(sci, inode); 487 err = nilfs_segctor_feed_segment(sci); 488 if (err) 489 return err; 490 goto retry; 491 } 492 if (unlikely(required)) { 493 err = nilfs_segbuf_extend_segsum(segbuf); 494 if (unlikely(err)) 495 goto failed; 496 } 497 if (sci->sc_blk_cnt == 0) 498 nilfs_segctor_begin_finfo(sci, inode); 499 500 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size); 501 /* Substitution to vblocknr is delayed until update_blocknr() */ 502 nilfs_segbuf_add_file_buffer(segbuf, bh); 503 sci->sc_blk_cnt++; 504 failed: 505 return err; 506 } 507 508 /* 509 * Callback functions that enumerate, mark, and collect dirty blocks 510 */ 511 static int nilfs_collect_file_data(struct nilfs_sc_info *sci, 512 struct buffer_head *bh, struct inode *inode) 513 { 514 int err; 515 516 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 517 if (err < 0) 518 return err; 519 520 err = nilfs_segctor_add_file_block(sci, bh, inode, 521 sizeof(struct nilfs_binfo_v)); 522 if (!err) 523 sci->sc_datablk_cnt++; 524 return err; 525 } 526 527 static int nilfs_collect_file_node(struct nilfs_sc_info *sci, 528 struct buffer_head *bh, 529 struct inode *inode) 530 { 531 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 532 } 533 534 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci, 535 struct buffer_head *bh, 536 struct inode *inode) 537 { 538 WARN_ON(!buffer_dirty(bh)); 539 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); 540 } 541 542 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci, 543 struct nilfs_segsum_pointer *ssp, 544 union nilfs_binfo *binfo) 545 { 546 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry( 547 sci, ssp, sizeof(*binfo_v)); 548 *binfo_v = binfo->bi_v; 549 } 550 551 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci, 552 struct nilfs_segsum_pointer *ssp, 553 union nilfs_binfo *binfo) 554 { 555 __le64 *vblocknr = nilfs_segctor_map_segsum_entry( 556 sci, ssp, sizeof(*vblocknr)); 557 *vblocknr = binfo->bi_v.bi_vblocknr; 558 } 559 560 static struct nilfs_sc_operations nilfs_sc_file_ops = { 561 .collect_data = nilfs_collect_file_data, 562 .collect_node = nilfs_collect_file_node, 563 .collect_bmap = nilfs_collect_file_bmap, 564 .write_data_binfo = nilfs_write_file_data_binfo, 565 .write_node_binfo = nilfs_write_file_node_binfo, 566 }; 567 568 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci, 569 struct buffer_head *bh, struct inode *inode) 570 { 571 int err; 572 573 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 574 if (err < 0) 575 return err; 576 577 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); 578 if (!err) 579 sci->sc_datablk_cnt++; 580 return err; 581 } 582 583 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci, 584 struct buffer_head *bh, struct inode *inode) 585 { 586 WARN_ON(!buffer_dirty(bh)); 587 return nilfs_segctor_add_file_block(sci, bh, inode, 588 sizeof(struct nilfs_binfo_dat)); 589 } 590 591 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci, 592 struct nilfs_segsum_pointer *ssp, 593 union nilfs_binfo *binfo) 594 { 595 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp, 596 sizeof(*blkoff)); 597 *blkoff = binfo->bi_dat.bi_blkoff; 598 } 599 600 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci, 601 struct nilfs_segsum_pointer *ssp, 602 union nilfs_binfo *binfo) 603 { 604 struct nilfs_binfo_dat *binfo_dat = 605 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat)); 606 *binfo_dat = binfo->bi_dat; 607 } 608 609 static struct nilfs_sc_operations nilfs_sc_dat_ops = { 610 .collect_data = nilfs_collect_dat_data, 611 .collect_node = nilfs_collect_file_node, 612 .collect_bmap = nilfs_collect_dat_bmap, 613 .write_data_binfo = nilfs_write_dat_data_binfo, 614 .write_node_binfo = nilfs_write_dat_node_binfo, 615 }; 616 617 static struct nilfs_sc_operations nilfs_sc_dsync_ops = { 618 .collect_data = nilfs_collect_file_data, 619 .collect_node = NULL, 620 .collect_bmap = NULL, 621 .write_data_binfo = nilfs_write_file_data_binfo, 622 .write_node_binfo = NULL, 623 }; 624 625 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode, 626 struct list_head *listp, 627 size_t nlimit, 628 loff_t start, loff_t end) 629 { 630 struct address_space *mapping = inode->i_mapping; 631 struct pagevec pvec; 632 pgoff_t index = 0, last = ULONG_MAX; 633 size_t ndirties = 0; 634 int i; 635 636 if (unlikely(start != 0 || end != LLONG_MAX)) { 637 /* 638 * A valid range is given for sync-ing data pages. The 639 * range is rounded to per-page; extra dirty buffers 640 * may be included if blocksize < pagesize. 641 */ 642 index = start >> PAGE_SHIFT; 643 last = end >> PAGE_SHIFT; 644 } 645 pagevec_init(&pvec, 0); 646 repeat: 647 if (unlikely(index > last) || 648 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 649 min_t(pgoff_t, last - index, 650 PAGEVEC_SIZE - 1) + 1)) 651 return ndirties; 652 653 for (i = 0; i < pagevec_count(&pvec); i++) { 654 struct buffer_head *bh, *head; 655 struct page *page = pvec.pages[i]; 656 657 if (unlikely(page->index > last)) 658 break; 659 660 if (mapping->host) { 661 lock_page(page); 662 if (!page_has_buffers(page)) 663 create_empty_buffers(page, 664 1 << inode->i_blkbits, 0); 665 unlock_page(page); 666 } 667 668 bh = head = page_buffers(page); 669 do { 670 if (!buffer_dirty(bh)) 671 continue; 672 get_bh(bh); 673 list_add_tail(&bh->b_assoc_buffers, listp); 674 ndirties++; 675 if (unlikely(ndirties >= nlimit)) { 676 pagevec_release(&pvec); 677 cond_resched(); 678 return ndirties; 679 } 680 } while (bh = bh->b_this_page, bh != head); 681 } 682 pagevec_release(&pvec); 683 cond_resched(); 684 goto repeat; 685 } 686 687 static void nilfs_lookup_dirty_node_buffers(struct inode *inode, 688 struct list_head *listp) 689 { 690 struct nilfs_inode_info *ii = NILFS_I(inode); 691 struct address_space *mapping = &ii->i_btnode_cache; 692 struct pagevec pvec; 693 struct buffer_head *bh, *head; 694 unsigned int i; 695 pgoff_t index = 0; 696 697 pagevec_init(&pvec, 0); 698 699 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 700 PAGEVEC_SIZE)) { 701 for (i = 0; i < pagevec_count(&pvec); i++) { 702 bh = head = page_buffers(pvec.pages[i]); 703 do { 704 if (buffer_dirty(bh)) { 705 get_bh(bh); 706 list_add_tail(&bh->b_assoc_buffers, 707 listp); 708 } 709 bh = bh->b_this_page; 710 } while (bh != head); 711 } 712 pagevec_release(&pvec); 713 cond_resched(); 714 } 715 } 716 717 static void nilfs_dispose_list(struct nilfs_sb_info *sbi, 718 struct list_head *head, int force) 719 { 720 struct nilfs_inode_info *ii, *n; 721 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii; 722 unsigned nv = 0; 723 724 while (!list_empty(head)) { 725 spin_lock(&sbi->s_inode_lock); 726 list_for_each_entry_safe(ii, n, head, i_dirty) { 727 list_del_init(&ii->i_dirty); 728 if (force) { 729 if (unlikely(ii->i_bh)) { 730 brelse(ii->i_bh); 731 ii->i_bh = NULL; 732 } 733 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) { 734 set_bit(NILFS_I_QUEUED, &ii->i_state); 735 list_add_tail(&ii->i_dirty, 736 &sbi->s_dirty_files); 737 continue; 738 } 739 ivec[nv++] = ii; 740 if (nv == SC_N_INODEVEC) 741 break; 742 } 743 spin_unlock(&sbi->s_inode_lock); 744 745 for (pii = ivec; nv > 0; pii++, nv--) 746 iput(&(*pii)->vfs_inode); 747 } 748 } 749 750 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs, 751 struct nilfs_root *root) 752 { 753 int ret = 0; 754 755 if (nilfs_mdt_fetch_dirty(root->ifile)) 756 ret++; 757 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile)) 758 ret++; 759 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile)) 760 ret++; 761 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat)) 762 ret++; 763 return ret; 764 } 765 766 static int nilfs_segctor_clean(struct nilfs_sc_info *sci) 767 { 768 return list_empty(&sci->sc_dirty_files) && 769 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) && 770 sci->sc_nfreesegs == 0 && 771 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes)); 772 } 773 774 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci) 775 { 776 struct nilfs_sb_info *sbi = sci->sc_sbi; 777 int ret = 0; 778 779 if (nilfs_test_metadata_dirty(sbi->s_nilfs, sci->sc_root)) 780 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 781 782 spin_lock(&sbi->s_inode_lock); 783 if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci)) 784 ret++; 785 786 spin_unlock(&sbi->s_inode_lock); 787 return ret; 788 } 789 790 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci) 791 { 792 struct nilfs_sb_info *sbi = sci->sc_sbi; 793 struct the_nilfs *nilfs = sbi->s_nilfs; 794 795 nilfs_mdt_clear_dirty(sci->sc_root->ifile); 796 nilfs_mdt_clear_dirty(nilfs->ns_cpfile); 797 nilfs_mdt_clear_dirty(nilfs->ns_sufile); 798 nilfs_mdt_clear_dirty(nilfs->ns_dat); 799 } 800 801 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci) 802 { 803 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs; 804 struct buffer_head *bh_cp; 805 struct nilfs_checkpoint *raw_cp; 806 int err; 807 808 /* XXX: this interface will be changed */ 809 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1, 810 &raw_cp, &bh_cp); 811 if (likely(!err)) { 812 /* The following code is duplicated with cpfile. But, it is 813 needed to collect the checkpoint even if it was not newly 814 created */ 815 nilfs_mdt_mark_buffer_dirty(bh_cp); 816 nilfs_mdt_mark_dirty(nilfs->ns_cpfile); 817 nilfs_cpfile_put_checkpoint( 818 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 819 } else 820 WARN_ON(err == -EINVAL || err == -ENOENT); 821 822 return err; 823 } 824 825 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci) 826 { 827 struct nilfs_sb_info *sbi = sci->sc_sbi; 828 struct the_nilfs *nilfs = sbi->s_nilfs; 829 struct buffer_head *bh_cp; 830 struct nilfs_checkpoint *raw_cp; 831 int err; 832 833 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0, 834 &raw_cp, &bh_cp); 835 if (unlikely(err)) { 836 WARN_ON(err == -EINVAL || err == -ENOENT); 837 goto failed_ibh; 838 } 839 raw_cp->cp_snapshot_list.ssl_next = 0; 840 raw_cp->cp_snapshot_list.ssl_prev = 0; 841 raw_cp->cp_inodes_count = 842 cpu_to_le64(atomic_read(&sci->sc_root->inodes_count)); 843 raw_cp->cp_blocks_count = 844 cpu_to_le64(atomic_read(&sci->sc_root->blocks_count)); 845 raw_cp->cp_nblk_inc = 846 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc); 847 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime); 848 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno); 849 850 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 851 nilfs_checkpoint_clear_minor(raw_cp); 852 else 853 nilfs_checkpoint_set_minor(raw_cp); 854 855 nilfs_write_inode_common(sci->sc_root->ifile, 856 &raw_cp->cp_ifile_inode, 1); 857 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 858 return 0; 859 860 failed_ibh: 861 return err; 862 } 863 864 static void nilfs_fill_in_file_bmap(struct inode *ifile, 865 struct nilfs_inode_info *ii) 866 867 { 868 struct buffer_head *ibh; 869 struct nilfs_inode *raw_inode; 870 871 if (test_bit(NILFS_I_BMAP, &ii->i_state)) { 872 ibh = ii->i_bh; 873 BUG_ON(!ibh); 874 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino, 875 ibh); 876 nilfs_bmap_write(ii->i_bmap, raw_inode); 877 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh); 878 } 879 } 880 881 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci) 882 { 883 struct nilfs_inode_info *ii; 884 885 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) { 886 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii); 887 set_bit(NILFS_I_COLLECTED, &ii->i_state); 888 } 889 } 890 891 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci, 892 struct the_nilfs *nilfs) 893 { 894 struct buffer_head *bh_sr; 895 struct nilfs_super_root *raw_sr; 896 unsigned isz = nilfs->ns_inode_size; 897 898 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root; 899 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 900 901 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES); 902 raw_sr->sr_nongc_ctime 903 = cpu_to_le64(nilfs_doing_gc() ? 904 nilfs->ns_nongc_ctime : sci->sc_seg_ctime); 905 raw_sr->sr_flags = 0; 906 907 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr + 908 NILFS_SR_DAT_OFFSET(isz), 1); 909 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr + 910 NILFS_SR_CPFILE_OFFSET(isz), 1); 911 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr + 912 NILFS_SR_SUFILE_OFFSET(isz), 1); 913 } 914 915 static void nilfs_redirty_inodes(struct list_head *head) 916 { 917 struct nilfs_inode_info *ii; 918 919 list_for_each_entry(ii, head, i_dirty) { 920 if (test_bit(NILFS_I_COLLECTED, &ii->i_state)) 921 clear_bit(NILFS_I_COLLECTED, &ii->i_state); 922 } 923 } 924 925 static void nilfs_drop_collected_inodes(struct list_head *head) 926 { 927 struct nilfs_inode_info *ii; 928 929 list_for_each_entry(ii, head, i_dirty) { 930 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state)) 931 continue; 932 933 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state); 934 set_bit(NILFS_I_UPDATED, &ii->i_state); 935 } 936 } 937 938 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci, 939 struct inode *inode, 940 struct list_head *listp, 941 int (*collect)(struct nilfs_sc_info *, 942 struct buffer_head *, 943 struct inode *)) 944 { 945 struct buffer_head *bh, *n; 946 int err = 0; 947 948 if (collect) { 949 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) { 950 list_del_init(&bh->b_assoc_buffers); 951 err = collect(sci, bh, inode); 952 brelse(bh); 953 if (unlikely(err)) 954 goto dispose_buffers; 955 } 956 return 0; 957 } 958 959 dispose_buffers: 960 while (!list_empty(listp)) { 961 bh = list_entry(listp->next, struct buffer_head, 962 b_assoc_buffers); 963 list_del_init(&bh->b_assoc_buffers); 964 brelse(bh); 965 } 966 return err; 967 } 968 969 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci) 970 { 971 /* Remaining number of blocks within segment buffer */ 972 return sci->sc_segbuf_nblocks - 973 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks); 974 } 975 976 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci, 977 struct inode *inode, 978 struct nilfs_sc_operations *sc_ops) 979 { 980 LIST_HEAD(data_buffers); 981 LIST_HEAD(node_buffers); 982 int err; 983 984 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { 985 size_t n, rest = nilfs_segctor_buffer_rest(sci); 986 987 n = nilfs_lookup_dirty_data_buffers( 988 inode, &data_buffers, rest + 1, 0, LLONG_MAX); 989 if (n > rest) { 990 err = nilfs_segctor_apply_buffers( 991 sci, inode, &data_buffers, 992 sc_ops->collect_data); 993 BUG_ON(!err); /* always receive -E2BIG or true error */ 994 goto break_or_fail; 995 } 996 } 997 nilfs_lookup_dirty_node_buffers(inode, &node_buffers); 998 999 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { 1000 err = nilfs_segctor_apply_buffers( 1001 sci, inode, &data_buffers, sc_ops->collect_data); 1002 if (unlikely(err)) { 1003 /* dispose node list */ 1004 nilfs_segctor_apply_buffers( 1005 sci, inode, &node_buffers, NULL); 1006 goto break_or_fail; 1007 } 1008 sci->sc_stage.flags |= NILFS_CF_NODE; 1009 } 1010 /* Collect node */ 1011 err = nilfs_segctor_apply_buffers( 1012 sci, inode, &node_buffers, sc_ops->collect_node); 1013 if (unlikely(err)) 1014 goto break_or_fail; 1015 1016 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers); 1017 err = nilfs_segctor_apply_buffers( 1018 sci, inode, &node_buffers, sc_ops->collect_bmap); 1019 if (unlikely(err)) 1020 goto break_or_fail; 1021 1022 nilfs_segctor_end_finfo(sci, inode); 1023 sci->sc_stage.flags &= ~NILFS_CF_NODE; 1024 1025 break_or_fail: 1026 return err; 1027 } 1028 1029 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci, 1030 struct inode *inode) 1031 { 1032 LIST_HEAD(data_buffers); 1033 size_t n, rest = nilfs_segctor_buffer_rest(sci); 1034 int err; 1035 1036 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1, 1037 sci->sc_dsync_start, 1038 sci->sc_dsync_end); 1039 1040 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers, 1041 nilfs_collect_file_data); 1042 if (!err) { 1043 nilfs_segctor_end_finfo(sci, inode); 1044 BUG_ON(n > rest); 1045 /* always receive -E2BIG or true error if n > rest */ 1046 } 1047 return err; 1048 } 1049 1050 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode) 1051 { 1052 struct nilfs_sb_info *sbi = sci->sc_sbi; 1053 struct the_nilfs *nilfs = sbi->s_nilfs; 1054 struct list_head *head; 1055 struct nilfs_inode_info *ii; 1056 size_t ndone; 1057 int err = 0; 1058 1059 switch (sci->sc_stage.scnt) { 1060 case NILFS_ST_INIT: 1061 /* Pre-processes */ 1062 sci->sc_stage.flags = 0; 1063 1064 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) { 1065 sci->sc_nblk_inc = 0; 1066 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN; 1067 if (mode == SC_LSEG_DSYNC) { 1068 sci->sc_stage.scnt = NILFS_ST_DSYNC; 1069 goto dsync_mode; 1070 } 1071 } 1072 1073 sci->sc_stage.dirty_file_ptr = NULL; 1074 sci->sc_stage.gc_inode_ptr = NULL; 1075 if (mode == SC_FLUSH_DAT) { 1076 sci->sc_stage.scnt = NILFS_ST_DAT; 1077 goto dat_stage; 1078 } 1079 sci->sc_stage.scnt++; /* Fall through */ 1080 case NILFS_ST_GC: 1081 if (nilfs_doing_gc()) { 1082 head = &sci->sc_gc_inodes; 1083 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr, 1084 head, i_dirty); 1085 list_for_each_entry_continue(ii, head, i_dirty) { 1086 err = nilfs_segctor_scan_file( 1087 sci, &ii->vfs_inode, 1088 &nilfs_sc_file_ops); 1089 if (unlikely(err)) { 1090 sci->sc_stage.gc_inode_ptr = list_entry( 1091 ii->i_dirty.prev, 1092 struct nilfs_inode_info, 1093 i_dirty); 1094 goto break_or_fail; 1095 } 1096 set_bit(NILFS_I_COLLECTED, &ii->i_state); 1097 } 1098 sci->sc_stage.gc_inode_ptr = NULL; 1099 } 1100 sci->sc_stage.scnt++; /* Fall through */ 1101 case NILFS_ST_FILE: 1102 head = &sci->sc_dirty_files; 1103 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head, 1104 i_dirty); 1105 list_for_each_entry_continue(ii, head, i_dirty) { 1106 clear_bit(NILFS_I_DIRTY, &ii->i_state); 1107 1108 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode, 1109 &nilfs_sc_file_ops); 1110 if (unlikely(err)) { 1111 sci->sc_stage.dirty_file_ptr = 1112 list_entry(ii->i_dirty.prev, 1113 struct nilfs_inode_info, 1114 i_dirty); 1115 goto break_or_fail; 1116 } 1117 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */ 1118 /* XXX: required ? */ 1119 } 1120 sci->sc_stage.dirty_file_ptr = NULL; 1121 if (mode == SC_FLUSH_FILE) { 1122 sci->sc_stage.scnt = NILFS_ST_DONE; 1123 return 0; 1124 } 1125 sci->sc_stage.scnt++; 1126 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED; 1127 /* Fall through */ 1128 case NILFS_ST_IFILE: 1129 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile, 1130 &nilfs_sc_file_ops); 1131 if (unlikely(err)) 1132 break; 1133 sci->sc_stage.scnt++; 1134 /* Creating a checkpoint */ 1135 err = nilfs_segctor_create_checkpoint(sci); 1136 if (unlikely(err)) 1137 break; 1138 /* Fall through */ 1139 case NILFS_ST_CPFILE: 1140 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile, 1141 &nilfs_sc_file_ops); 1142 if (unlikely(err)) 1143 break; 1144 sci->sc_stage.scnt++; /* Fall through */ 1145 case NILFS_ST_SUFILE: 1146 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs, 1147 sci->sc_nfreesegs, &ndone); 1148 if (unlikely(err)) { 1149 nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1150 sci->sc_freesegs, ndone, 1151 NULL); 1152 break; 1153 } 1154 sci->sc_stage.flags |= NILFS_CF_SUFREED; 1155 1156 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile, 1157 &nilfs_sc_file_ops); 1158 if (unlikely(err)) 1159 break; 1160 sci->sc_stage.scnt++; /* Fall through */ 1161 case NILFS_ST_DAT: 1162 dat_stage: 1163 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat, 1164 &nilfs_sc_dat_ops); 1165 if (unlikely(err)) 1166 break; 1167 if (mode == SC_FLUSH_DAT) { 1168 sci->sc_stage.scnt = NILFS_ST_DONE; 1169 return 0; 1170 } 1171 sci->sc_stage.scnt++; /* Fall through */ 1172 case NILFS_ST_SR: 1173 if (mode == SC_LSEG_SR) { 1174 /* Appending a super root */ 1175 err = nilfs_segctor_add_super_root(sci); 1176 if (unlikely(err)) 1177 break; 1178 } 1179 /* End of a logical segment */ 1180 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; 1181 sci->sc_stage.scnt = NILFS_ST_DONE; 1182 return 0; 1183 case NILFS_ST_DSYNC: 1184 dsync_mode: 1185 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT; 1186 ii = sci->sc_dsync_inode; 1187 if (!test_bit(NILFS_I_BUSY, &ii->i_state)) 1188 break; 1189 1190 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode); 1191 if (unlikely(err)) 1192 break; 1193 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; 1194 sci->sc_stage.scnt = NILFS_ST_DONE; 1195 return 0; 1196 case NILFS_ST_DONE: 1197 return 0; 1198 default: 1199 BUG(); 1200 } 1201 1202 break_or_fail: 1203 return err; 1204 } 1205 1206 /** 1207 * nilfs_segctor_begin_construction - setup segment buffer to make a new log 1208 * @sci: nilfs_sc_info 1209 * @nilfs: nilfs object 1210 */ 1211 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci, 1212 struct the_nilfs *nilfs) 1213 { 1214 struct nilfs_segment_buffer *segbuf, *prev; 1215 __u64 nextnum; 1216 int err, alloc = 0; 1217 1218 segbuf = nilfs_segbuf_new(sci->sc_super); 1219 if (unlikely(!segbuf)) 1220 return -ENOMEM; 1221 1222 if (list_empty(&sci->sc_write_logs)) { 1223 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 1224 nilfs->ns_pseg_offset, nilfs); 1225 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { 1226 nilfs_shift_to_next_segment(nilfs); 1227 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs); 1228 } 1229 1230 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq; 1231 nextnum = nilfs->ns_nextnum; 1232 1233 if (nilfs->ns_segnum == nilfs->ns_nextnum) 1234 /* Start from the head of a new full segment */ 1235 alloc++; 1236 } else { 1237 /* Continue logs */ 1238 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1239 nilfs_segbuf_map_cont(segbuf, prev); 1240 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq; 1241 nextnum = prev->sb_nextnum; 1242 1243 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { 1244 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); 1245 segbuf->sb_sum.seg_seq++; 1246 alloc++; 1247 } 1248 } 1249 1250 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum); 1251 if (err) 1252 goto failed; 1253 1254 if (alloc) { 1255 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum); 1256 if (err) 1257 goto failed; 1258 } 1259 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs); 1260 1261 BUG_ON(!list_empty(&sci->sc_segbufs)); 1262 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs); 1263 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks; 1264 return 0; 1265 1266 failed: 1267 nilfs_segbuf_free(segbuf); 1268 return err; 1269 } 1270 1271 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci, 1272 struct the_nilfs *nilfs, int nadd) 1273 { 1274 struct nilfs_segment_buffer *segbuf, *prev; 1275 struct inode *sufile = nilfs->ns_sufile; 1276 __u64 nextnextnum; 1277 LIST_HEAD(list); 1278 int err, ret, i; 1279 1280 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs); 1281 /* 1282 * Since the segment specified with nextnum might be allocated during 1283 * the previous construction, the buffer including its segusage may 1284 * not be dirty. The following call ensures that the buffer is dirty 1285 * and will pin the buffer on memory until the sufile is written. 1286 */ 1287 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum); 1288 if (unlikely(err)) 1289 return err; 1290 1291 for (i = 0; i < nadd; i++) { 1292 /* extend segment info */ 1293 err = -ENOMEM; 1294 segbuf = nilfs_segbuf_new(sci->sc_super); 1295 if (unlikely(!segbuf)) 1296 goto failed; 1297 1298 /* map this buffer to region of segment on-disk */ 1299 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); 1300 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks; 1301 1302 /* allocate the next next full segment */ 1303 err = nilfs_sufile_alloc(sufile, &nextnextnum); 1304 if (unlikely(err)) 1305 goto failed_segbuf; 1306 1307 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1; 1308 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs); 1309 1310 list_add_tail(&segbuf->sb_list, &list); 1311 prev = segbuf; 1312 } 1313 list_splice_tail(&list, &sci->sc_segbufs); 1314 return 0; 1315 1316 failed_segbuf: 1317 nilfs_segbuf_free(segbuf); 1318 failed: 1319 list_for_each_entry(segbuf, &list, sb_list) { 1320 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1321 WARN_ON(ret); /* never fails */ 1322 } 1323 nilfs_destroy_logs(&list); 1324 return err; 1325 } 1326 1327 static void nilfs_free_incomplete_logs(struct list_head *logs, 1328 struct the_nilfs *nilfs) 1329 { 1330 struct nilfs_segment_buffer *segbuf, *prev; 1331 struct inode *sufile = nilfs->ns_sufile; 1332 int ret; 1333 1334 segbuf = NILFS_FIRST_SEGBUF(logs); 1335 if (nilfs->ns_nextnum != segbuf->sb_nextnum) { 1336 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1337 WARN_ON(ret); /* never fails */ 1338 } 1339 if (atomic_read(&segbuf->sb_err)) { 1340 /* Case 1: The first segment failed */ 1341 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start) 1342 /* Case 1a: Partial segment appended into an existing 1343 segment */ 1344 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start, 1345 segbuf->sb_fseg_end); 1346 else /* Case 1b: New full segment */ 1347 set_nilfs_discontinued(nilfs); 1348 } 1349 1350 prev = segbuf; 1351 list_for_each_entry_continue(segbuf, logs, sb_list) { 1352 if (prev->sb_nextnum != segbuf->sb_nextnum) { 1353 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1354 WARN_ON(ret); /* never fails */ 1355 } 1356 if (atomic_read(&segbuf->sb_err) && 1357 segbuf->sb_segnum != nilfs->ns_nextnum) 1358 /* Case 2: extended segment (!= next) failed */ 1359 nilfs_sufile_set_error(sufile, segbuf->sb_segnum); 1360 prev = segbuf; 1361 } 1362 } 1363 1364 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci, 1365 struct inode *sufile) 1366 { 1367 struct nilfs_segment_buffer *segbuf; 1368 unsigned long live_blocks; 1369 int ret; 1370 1371 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1372 live_blocks = segbuf->sb_sum.nblocks + 1373 (segbuf->sb_pseg_start - segbuf->sb_fseg_start); 1374 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1375 live_blocks, 1376 sci->sc_seg_ctime); 1377 WARN_ON(ret); /* always succeed because the segusage is dirty */ 1378 } 1379 } 1380 1381 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile) 1382 { 1383 struct nilfs_segment_buffer *segbuf; 1384 int ret; 1385 1386 segbuf = NILFS_FIRST_SEGBUF(logs); 1387 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1388 segbuf->sb_pseg_start - 1389 segbuf->sb_fseg_start, 0); 1390 WARN_ON(ret); /* always succeed because the segusage is dirty */ 1391 1392 list_for_each_entry_continue(segbuf, logs, sb_list) { 1393 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1394 0, 0); 1395 WARN_ON(ret); /* always succeed */ 1396 } 1397 } 1398 1399 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci, 1400 struct nilfs_segment_buffer *last, 1401 struct inode *sufile) 1402 { 1403 struct nilfs_segment_buffer *segbuf = last; 1404 int ret; 1405 1406 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) { 1407 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks; 1408 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1409 WARN_ON(ret); 1410 } 1411 nilfs_truncate_logs(&sci->sc_segbufs, last); 1412 } 1413 1414 1415 static int nilfs_segctor_collect(struct nilfs_sc_info *sci, 1416 struct the_nilfs *nilfs, int mode) 1417 { 1418 struct nilfs_cstage prev_stage = sci->sc_stage; 1419 int err, nadd = 1; 1420 1421 /* Collection retry loop */ 1422 for (;;) { 1423 sci->sc_nblk_this_inc = 0; 1424 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs); 1425 1426 err = nilfs_segctor_reset_segment_buffer(sci); 1427 if (unlikely(err)) 1428 goto failed; 1429 1430 err = nilfs_segctor_collect_blocks(sci, mode); 1431 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; 1432 if (!err) 1433 break; 1434 1435 if (unlikely(err != -E2BIG)) 1436 goto failed; 1437 1438 /* The current segment is filled up */ 1439 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE) 1440 break; 1441 1442 nilfs_clear_logs(&sci->sc_segbufs); 1443 1444 err = nilfs_segctor_extend_segments(sci, nilfs, nadd); 1445 if (unlikely(err)) 1446 return err; 1447 1448 if (sci->sc_stage.flags & NILFS_CF_SUFREED) { 1449 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1450 sci->sc_freesegs, 1451 sci->sc_nfreesegs, 1452 NULL); 1453 WARN_ON(err); /* do not happen */ 1454 } 1455 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA); 1456 sci->sc_stage = prev_stage; 1457 } 1458 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile); 1459 return 0; 1460 1461 failed: 1462 return err; 1463 } 1464 1465 static void nilfs_list_replace_buffer(struct buffer_head *old_bh, 1466 struct buffer_head *new_bh) 1467 { 1468 BUG_ON(!list_empty(&new_bh->b_assoc_buffers)); 1469 1470 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers); 1471 /* The caller must release old_bh */ 1472 } 1473 1474 static int 1475 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci, 1476 struct nilfs_segment_buffer *segbuf, 1477 int mode) 1478 { 1479 struct inode *inode = NULL; 1480 sector_t blocknr; 1481 unsigned long nfinfo = segbuf->sb_sum.nfinfo; 1482 unsigned long nblocks = 0, ndatablk = 0; 1483 struct nilfs_sc_operations *sc_op = NULL; 1484 struct nilfs_segsum_pointer ssp; 1485 struct nilfs_finfo *finfo = NULL; 1486 union nilfs_binfo binfo; 1487 struct buffer_head *bh, *bh_org; 1488 ino_t ino = 0; 1489 int err = 0; 1490 1491 if (!nfinfo) 1492 goto out; 1493 1494 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk; 1495 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); 1496 ssp.offset = sizeof(struct nilfs_segment_summary); 1497 1498 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { 1499 if (bh == segbuf->sb_super_root) 1500 break; 1501 if (!finfo) { 1502 finfo = nilfs_segctor_map_segsum_entry( 1503 sci, &ssp, sizeof(*finfo)); 1504 ino = le64_to_cpu(finfo->fi_ino); 1505 nblocks = le32_to_cpu(finfo->fi_nblocks); 1506 ndatablk = le32_to_cpu(finfo->fi_ndatablk); 1507 1508 if (buffer_nilfs_node(bh)) 1509 inode = NILFS_BTNC_I(bh->b_page->mapping); 1510 else 1511 inode = NILFS_AS_I(bh->b_page->mapping); 1512 1513 if (mode == SC_LSEG_DSYNC) 1514 sc_op = &nilfs_sc_dsync_ops; 1515 else if (ino == NILFS_DAT_INO) 1516 sc_op = &nilfs_sc_dat_ops; 1517 else /* file blocks */ 1518 sc_op = &nilfs_sc_file_ops; 1519 } 1520 bh_org = bh; 1521 get_bh(bh_org); 1522 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr, 1523 &binfo); 1524 if (bh != bh_org) 1525 nilfs_list_replace_buffer(bh_org, bh); 1526 brelse(bh_org); 1527 if (unlikely(err)) 1528 goto failed_bmap; 1529 1530 if (ndatablk > 0) 1531 sc_op->write_data_binfo(sci, &ssp, &binfo); 1532 else 1533 sc_op->write_node_binfo(sci, &ssp, &binfo); 1534 1535 blocknr++; 1536 if (--nblocks == 0) { 1537 finfo = NULL; 1538 if (--nfinfo == 0) 1539 break; 1540 } else if (ndatablk > 0) 1541 ndatablk--; 1542 } 1543 out: 1544 return 0; 1545 1546 failed_bmap: 1547 return err; 1548 } 1549 1550 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode) 1551 { 1552 struct nilfs_segment_buffer *segbuf; 1553 int err; 1554 1555 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1556 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode); 1557 if (unlikely(err)) 1558 return err; 1559 nilfs_segbuf_fill_in_segsum(segbuf); 1560 } 1561 return 0; 1562 } 1563 1564 static int 1565 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out) 1566 { 1567 struct page *clone_page; 1568 struct buffer_head *bh, *head, *bh2; 1569 void *kaddr; 1570 1571 bh = head = page_buffers(page); 1572 1573 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0); 1574 if (unlikely(!clone_page)) 1575 return -ENOMEM; 1576 1577 bh2 = page_buffers(clone_page); 1578 kaddr = kmap_atomic(page, KM_USER0); 1579 do { 1580 if (list_empty(&bh->b_assoc_buffers)) 1581 continue; 1582 get_bh(bh2); 1583 page_cache_get(clone_page); /* for each bh */ 1584 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size); 1585 bh2->b_blocknr = bh->b_blocknr; 1586 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers); 1587 list_add_tail(&bh->b_assoc_buffers, out); 1588 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head); 1589 kunmap_atomic(kaddr, KM_USER0); 1590 1591 if (!TestSetPageWriteback(clone_page)) 1592 account_page_writeback(clone_page); 1593 unlock_page(clone_page); 1594 1595 return 0; 1596 } 1597 1598 static int nilfs_test_page_to_be_frozen(struct page *page) 1599 { 1600 struct address_space *mapping = page->mapping; 1601 1602 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode)) 1603 return 0; 1604 1605 if (page_mapped(page)) { 1606 ClearPageChecked(page); 1607 return 1; 1608 } 1609 return PageChecked(page); 1610 } 1611 1612 static int nilfs_begin_page_io(struct page *page, struct list_head *out) 1613 { 1614 if (!page || PageWriteback(page)) 1615 /* For split b-tree node pages, this function may be called 1616 twice. We ignore the 2nd or later calls by this check. */ 1617 return 0; 1618 1619 lock_page(page); 1620 clear_page_dirty_for_io(page); 1621 set_page_writeback(page); 1622 unlock_page(page); 1623 1624 if (nilfs_test_page_to_be_frozen(page)) { 1625 int err = nilfs_copy_replace_page_buffers(page, out); 1626 if (unlikely(err)) 1627 return err; 1628 } 1629 return 0; 1630 } 1631 1632 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci, 1633 struct page **failed_page) 1634 { 1635 struct nilfs_segment_buffer *segbuf; 1636 struct page *bd_page = NULL, *fs_page = NULL; 1637 struct list_head *list = &sci->sc_copied_buffers; 1638 int err; 1639 1640 *failed_page = NULL; 1641 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1642 struct buffer_head *bh; 1643 1644 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1645 b_assoc_buffers) { 1646 if (bh->b_page != bd_page) { 1647 if (bd_page) { 1648 lock_page(bd_page); 1649 clear_page_dirty_for_io(bd_page); 1650 set_page_writeback(bd_page); 1651 unlock_page(bd_page); 1652 } 1653 bd_page = bh->b_page; 1654 } 1655 } 1656 1657 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1658 b_assoc_buffers) { 1659 if (bh == segbuf->sb_super_root) { 1660 if (bh->b_page != bd_page) { 1661 lock_page(bd_page); 1662 clear_page_dirty_for_io(bd_page); 1663 set_page_writeback(bd_page); 1664 unlock_page(bd_page); 1665 bd_page = bh->b_page; 1666 } 1667 break; 1668 } 1669 if (bh->b_page != fs_page) { 1670 err = nilfs_begin_page_io(fs_page, list); 1671 if (unlikely(err)) { 1672 *failed_page = fs_page; 1673 goto out; 1674 } 1675 fs_page = bh->b_page; 1676 } 1677 } 1678 } 1679 if (bd_page) { 1680 lock_page(bd_page); 1681 clear_page_dirty_for_io(bd_page); 1682 set_page_writeback(bd_page); 1683 unlock_page(bd_page); 1684 } 1685 err = nilfs_begin_page_io(fs_page, list); 1686 if (unlikely(err)) 1687 *failed_page = fs_page; 1688 out: 1689 return err; 1690 } 1691 1692 static int nilfs_segctor_write(struct nilfs_sc_info *sci, 1693 struct the_nilfs *nilfs) 1694 { 1695 int ret; 1696 1697 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs); 1698 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs); 1699 return ret; 1700 } 1701 1702 static void __nilfs_end_page_io(struct page *page, int err) 1703 { 1704 if (!err) { 1705 if (!nilfs_page_buffers_clean(page)) 1706 __set_page_dirty_nobuffers(page); 1707 ClearPageError(page); 1708 } else { 1709 __set_page_dirty_nobuffers(page); 1710 SetPageError(page); 1711 } 1712 1713 if (buffer_nilfs_allocated(page_buffers(page))) { 1714 if (TestClearPageWriteback(page)) 1715 dec_zone_page_state(page, NR_WRITEBACK); 1716 } else 1717 end_page_writeback(page); 1718 } 1719 1720 static void nilfs_end_page_io(struct page *page, int err) 1721 { 1722 if (!page) 1723 return; 1724 1725 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) { 1726 /* 1727 * For b-tree node pages, this function may be called twice 1728 * or more because they might be split in a segment. 1729 */ 1730 if (PageDirty(page)) { 1731 /* 1732 * For pages holding split b-tree node buffers, dirty 1733 * flag on the buffers may be cleared discretely. 1734 * In that case, the page is once redirtied for 1735 * remaining buffers, and it must be cancelled if 1736 * all the buffers get cleaned later. 1737 */ 1738 lock_page(page); 1739 if (nilfs_page_buffers_clean(page)) 1740 __nilfs_clear_page_dirty(page); 1741 unlock_page(page); 1742 } 1743 return; 1744 } 1745 1746 __nilfs_end_page_io(page, err); 1747 } 1748 1749 static void nilfs_clear_copied_buffers(struct list_head *list, int err) 1750 { 1751 struct buffer_head *bh, *head; 1752 struct page *page; 1753 1754 while (!list_empty(list)) { 1755 bh = list_entry(list->next, struct buffer_head, 1756 b_assoc_buffers); 1757 page = bh->b_page; 1758 page_cache_get(page); 1759 head = bh = page_buffers(page); 1760 do { 1761 if (!list_empty(&bh->b_assoc_buffers)) { 1762 list_del_init(&bh->b_assoc_buffers); 1763 if (!err) { 1764 set_buffer_uptodate(bh); 1765 clear_buffer_dirty(bh); 1766 clear_buffer_delay(bh); 1767 clear_buffer_nilfs_volatile(bh); 1768 } 1769 brelse(bh); /* for b_assoc_buffers */ 1770 } 1771 } while ((bh = bh->b_this_page) != head); 1772 1773 __nilfs_end_page_io(page, err); 1774 page_cache_release(page); 1775 } 1776 } 1777 1778 static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page, 1779 int err) 1780 { 1781 struct nilfs_segment_buffer *segbuf; 1782 struct page *bd_page = NULL, *fs_page = NULL; 1783 struct buffer_head *bh; 1784 1785 if (list_empty(logs)) 1786 return; 1787 1788 list_for_each_entry(segbuf, logs, sb_list) { 1789 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1790 b_assoc_buffers) { 1791 if (bh->b_page != bd_page) { 1792 if (bd_page) 1793 end_page_writeback(bd_page); 1794 bd_page = bh->b_page; 1795 } 1796 } 1797 1798 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1799 b_assoc_buffers) { 1800 if (bh == segbuf->sb_super_root) { 1801 if (bh->b_page != bd_page) { 1802 end_page_writeback(bd_page); 1803 bd_page = bh->b_page; 1804 } 1805 break; 1806 } 1807 if (bh->b_page != fs_page) { 1808 nilfs_end_page_io(fs_page, err); 1809 if (fs_page && fs_page == failed_page) 1810 return; 1811 fs_page = bh->b_page; 1812 } 1813 } 1814 } 1815 if (bd_page) 1816 end_page_writeback(bd_page); 1817 1818 nilfs_end_page_io(fs_page, err); 1819 } 1820 1821 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci, 1822 struct the_nilfs *nilfs, int err) 1823 { 1824 LIST_HEAD(logs); 1825 int ret; 1826 1827 list_splice_tail_init(&sci->sc_write_logs, &logs); 1828 ret = nilfs_wait_on_logs(&logs); 1829 nilfs_abort_logs(&logs, NULL, ret ? : err); 1830 1831 list_splice_tail_init(&sci->sc_segbufs, &logs); 1832 nilfs_cancel_segusage(&logs, nilfs->ns_sufile); 1833 nilfs_free_incomplete_logs(&logs, nilfs); 1834 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err); 1835 1836 if (sci->sc_stage.flags & NILFS_CF_SUFREED) { 1837 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1838 sci->sc_freesegs, 1839 sci->sc_nfreesegs, 1840 NULL); 1841 WARN_ON(ret); /* do not happen */ 1842 } 1843 1844 nilfs_destroy_logs(&logs); 1845 } 1846 1847 static void nilfs_set_next_segment(struct the_nilfs *nilfs, 1848 struct nilfs_segment_buffer *segbuf) 1849 { 1850 nilfs->ns_segnum = segbuf->sb_segnum; 1851 nilfs->ns_nextnum = segbuf->sb_nextnum; 1852 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start 1853 + segbuf->sb_sum.nblocks; 1854 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq; 1855 nilfs->ns_ctime = segbuf->sb_sum.ctime; 1856 } 1857 1858 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) 1859 { 1860 struct nilfs_segment_buffer *segbuf; 1861 struct page *bd_page = NULL, *fs_page = NULL; 1862 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs; 1863 int update_sr = false; 1864 1865 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) { 1866 struct buffer_head *bh; 1867 1868 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1869 b_assoc_buffers) { 1870 set_buffer_uptodate(bh); 1871 clear_buffer_dirty(bh); 1872 if (bh->b_page != bd_page) { 1873 if (bd_page) 1874 end_page_writeback(bd_page); 1875 bd_page = bh->b_page; 1876 } 1877 } 1878 /* 1879 * We assume that the buffers which belong to the same page 1880 * continue over the buffer list. 1881 * Under this assumption, the last BHs of pages is 1882 * identifiable by the discontinuity of bh->b_page 1883 * (page != fs_page). 1884 * 1885 * For B-tree node blocks, however, this assumption is not 1886 * guaranteed. The cleanup code of B-tree node pages needs 1887 * special care. 1888 */ 1889 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1890 b_assoc_buffers) { 1891 set_buffer_uptodate(bh); 1892 clear_buffer_dirty(bh); 1893 clear_buffer_delay(bh); 1894 clear_buffer_nilfs_volatile(bh); 1895 clear_buffer_nilfs_redirected(bh); 1896 if (bh == segbuf->sb_super_root) { 1897 if (bh->b_page != bd_page) { 1898 end_page_writeback(bd_page); 1899 bd_page = bh->b_page; 1900 } 1901 update_sr = true; 1902 break; 1903 } 1904 if (bh->b_page != fs_page) { 1905 nilfs_end_page_io(fs_page, 0); 1906 fs_page = bh->b_page; 1907 } 1908 } 1909 1910 if (!nilfs_segbuf_simplex(segbuf)) { 1911 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) { 1912 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1913 sci->sc_lseg_stime = jiffies; 1914 } 1915 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND) 1916 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1917 } 1918 } 1919 /* 1920 * Since pages may continue over multiple segment buffers, 1921 * end of the last page must be checked outside of the loop. 1922 */ 1923 if (bd_page) 1924 end_page_writeback(bd_page); 1925 1926 nilfs_end_page_io(fs_page, 0); 1927 1928 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0); 1929 1930 nilfs_drop_collected_inodes(&sci->sc_dirty_files); 1931 1932 if (nilfs_doing_gc()) 1933 nilfs_drop_collected_inodes(&sci->sc_gc_inodes); 1934 else 1935 nilfs->ns_nongc_ctime = sci->sc_seg_ctime; 1936 1937 sci->sc_nblk_inc += sci->sc_nblk_this_inc; 1938 1939 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1940 nilfs_set_next_segment(nilfs, segbuf); 1941 1942 if (update_sr) { 1943 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start, 1944 segbuf->sb_sum.seg_seq, nilfs->ns_cno++); 1945 1946 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 1947 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags); 1948 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1949 nilfs_segctor_clear_metadata_dirty(sci); 1950 } else 1951 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1952 } 1953 1954 static int nilfs_segctor_wait(struct nilfs_sc_info *sci) 1955 { 1956 int ret; 1957 1958 ret = nilfs_wait_on_logs(&sci->sc_write_logs); 1959 if (!ret) { 1960 nilfs_segctor_complete_write(sci); 1961 nilfs_destroy_logs(&sci->sc_write_logs); 1962 } 1963 return ret; 1964 } 1965 1966 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci, 1967 struct nilfs_sb_info *sbi) 1968 { 1969 struct nilfs_inode_info *ii, *n; 1970 struct inode *ifile = sci->sc_root->ifile; 1971 1972 spin_lock(&sbi->s_inode_lock); 1973 retry: 1974 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) { 1975 if (!ii->i_bh) { 1976 struct buffer_head *ibh; 1977 int err; 1978 1979 spin_unlock(&sbi->s_inode_lock); 1980 err = nilfs_ifile_get_inode_block( 1981 ifile, ii->vfs_inode.i_ino, &ibh); 1982 if (unlikely(err)) { 1983 nilfs_warning(sbi->s_super, __func__, 1984 "failed to get inode block.\n"); 1985 return err; 1986 } 1987 nilfs_mdt_mark_buffer_dirty(ibh); 1988 nilfs_mdt_mark_dirty(ifile); 1989 spin_lock(&sbi->s_inode_lock); 1990 if (likely(!ii->i_bh)) 1991 ii->i_bh = ibh; 1992 else 1993 brelse(ibh); 1994 goto retry; 1995 } 1996 1997 clear_bit(NILFS_I_QUEUED, &ii->i_state); 1998 set_bit(NILFS_I_BUSY, &ii->i_state); 1999 list_del(&ii->i_dirty); 2000 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files); 2001 } 2002 spin_unlock(&sbi->s_inode_lock); 2003 2004 return 0; 2005 } 2006 2007 static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci, 2008 struct nilfs_sb_info *sbi) 2009 { 2010 struct nilfs_transaction_info *ti = current->journal_info; 2011 struct nilfs_inode_info *ii, *n; 2012 2013 spin_lock(&sbi->s_inode_lock); 2014 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) { 2015 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) || 2016 test_bit(NILFS_I_DIRTY, &ii->i_state)) 2017 continue; 2018 2019 clear_bit(NILFS_I_BUSY, &ii->i_state); 2020 brelse(ii->i_bh); 2021 ii->i_bh = NULL; 2022 list_del(&ii->i_dirty); 2023 list_add_tail(&ii->i_dirty, &ti->ti_garbage); 2024 } 2025 spin_unlock(&sbi->s_inode_lock); 2026 } 2027 2028 /* 2029 * Main procedure of segment constructor 2030 */ 2031 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) 2032 { 2033 struct nilfs_sb_info *sbi = sci->sc_sbi; 2034 struct the_nilfs *nilfs = sbi->s_nilfs; 2035 struct page *failed_page; 2036 int err; 2037 2038 sci->sc_stage.scnt = NILFS_ST_INIT; 2039 sci->sc_cno = nilfs->ns_cno; 2040 2041 err = nilfs_segctor_check_in_files(sci, sbi); 2042 if (unlikely(err)) 2043 goto out; 2044 2045 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 2046 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 2047 2048 if (nilfs_segctor_clean(sci)) 2049 goto out; 2050 2051 do { 2052 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK; 2053 2054 err = nilfs_segctor_begin_construction(sci, nilfs); 2055 if (unlikely(err)) 2056 goto out; 2057 2058 /* Update time stamp */ 2059 sci->sc_seg_ctime = get_seconds(); 2060 2061 err = nilfs_segctor_collect(sci, nilfs, mode); 2062 if (unlikely(err)) 2063 goto failed; 2064 2065 /* Avoid empty segment */ 2066 if (sci->sc_stage.scnt == NILFS_ST_DONE && 2067 nilfs_segbuf_empty(sci->sc_curseg)) { 2068 nilfs_segctor_abort_construction(sci, nilfs, 1); 2069 goto out; 2070 } 2071 2072 err = nilfs_segctor_assign(sci, mode); 2073 if (unlikely(err)) 2074 goto failed; 2075 2076 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 2077 nilfs_segctor_fill_in_file_bmap(sci); 2078 2079 if (mode == SC_LSEG_SR && 2080 sci->sc_stage.scnt >= NILFS_ST_CPFILE) { 2081 err = nilfs_segctor_fill_in_checkpoint(sci); 2082 if (unlikely(err)) 2083 goto failed_to_write; 2084 2085 nilfs_segctor_fill_in_super_root(sci, nilfs); 2086 } 2087 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile); 2088 2089 /* Write partial segments */ 2090 err = nilfs_segctor_prepare_write(sci, &failed_page); 2091 if (err) { 2092 nilfs_abort_logs(&sci->sc_segbufs, failed_page, err); 2093 goto failed_to_write; 2094 } 2095 2096 nilfs_add_checksums_on_logs(&sci->sc_segbufs, 2097 nilfs->ns_crc_seed); 2098 2099 err = nilfs_segctor_write(sci, nilfs); 2100 if (unlikely(err)) 2101 goto failed_to_write; 2102 2103 if (sci->sc_stage.scnt == NILFS_ST_DONE || 2104 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) { 2105 /* 2106 * At this point, we avoid double buffering 2107 * for blocksize < pagesize because page dirty 2108 * flag is turned off during write and dirty 2109 * buffers are not properly collected for 2110 * pages crossing over segments. 2111 */ 2112 err = nilfs_segctor_wait(sci); 2113 if (err) 2114 goto failed_to_write; 2115 } 2116 } while (sci->sc_stage.scnt != NILFS_ST_DONE); 2117 2118 out: 2119 nilfs_segctor_check_out_files(sci, sbi); 2120 return err; 2121 2122 failed_to_write: 2123 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 2124 nilfs_redirty_inodes(&sci->sc_dirty_files); 2125 2126 failed: 2127 if (nilfs_doing_gc()) 2128 nilfs_redirty_inodes(&sci->sc_gc_inodes); 2129 nilfs_segctor_abort_construction(sci, nilfs, err); 2130 goto out; 2131 } 2132 2133 /** 2134 * nilfs_segctor_start_timer - set timer of background write 2135 * @sci: nilfs_sc_info 2136 * 2137 * If the timer has already been set, it ignores the new request. 2138 * This function MUST be called within a section locking the segment 2139 * semaphore. 2140 */ 2141 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci) 2142 { 2143 spin_lock(&sci->sc_state_lock); 2144 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) { 2145 sci->sc_timer.expires = jiffies + sci->sc_interval; 2146 add_timer(&sci->sc_timer); 2147 sci->sc_state |= NILFS_SEGCTOR_COMMIT; 2148 } 2149 spin_unlock(&sci->sc_state_lock); 2150 } 2151 2152 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn) 2153 { 2154 spin_lock(&sci->sc_state_lock); 2155 if (!(sci->sc_flush_request & (1 << bn))) { 2156 unsigned long prev_req = sci->sc_flush_request; 2157 2158 sci->sc_flush_request |= (1 << bn); 2159 if (!prev_req) 2160 wake_up(&sci->sc_wait_daemon); 2161 } 2162 spin_unlock(&sci->sc_state_lock); 2163 } 2164 2165 /** 2166 * nilfs_flush_segment - trigger a segment construction for resource control 2167 * @sb: super block 2168 * @ino: inode number of the file to be flushed out. 2169 */ 2170 void nilfs_flush_segment(struct super_block *sb, ino_t ino) 2171 { 2172 struct nilfs_sb_info *sbi = NILFS_SB(sb); 2173 struct nilfs_sc_info *sci = NILFS_SC(sbi); 2174 2175 if (!sci || nilfs_doing_construction()) 2176 return; 2177 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0); 2178 /* assign bit 0 to data files */ 2179 } 2180 2181 struct nilfs_segctor_wait_request { 2182 wait_queue_t wq; 2183 __u32 seq; 2184 int err; 2185 atomic_t done; 2186 }; 2187 2188 static int nilfs_segctor_sync(struct nilfs_sc_info *sci) 2189 { 2190 struct nilfs_segctor_wait_request wait_req; 2191 int err = 0; 2192 2193 spin_lock(&sci->sc_state_lock); 2194 init_wait(&wait_req.wq); 2195 wait_req.err = 0; 2196 atomic_set(&wait_req.done, 0); 2197 wait_req.seq = ++sci->sc_seq_request; 2198 spin_unlock(&sci->sc_state_lock); 2199 2200 init_waitqueue_entry(&wait_req.wq, current); 2201 add_wait_queue(&sci->sc_wait_request, &wait_req.wq); 2202 set_current_state(TASK_INTERRUPTIBLE); 2203 wake_up(&sci->sc_wait_daemon); 2204 2205 for (;;) { 2206 if (atomic_read(&wait_req.done)) { 2207 err = wait_req.err; 2208 break; 2209 } 2210 if (!signal_pending(current)) { 2211 schedule(); 2212 continue; 2213 } 2214 err = -ERESTARTSYS; 2215 break; 2216 } 2217 finish_wait(&sci->sc_wait_request, &wait_req.wq); 2218 return err; 2219 } 2220 2221 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err) 2222 { 2223 struct nilfs_segctor_wait_request *wrq, *n; 2224 unsigned long flags; 2225 2226 spin_lock_irqsave(&sci->sc_wait_request.lock, flags); 2227 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list, 2228 wq.task_list) { 2229 if (!atomic_read(&wrq->done) && 2230 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) { 2231 wrq->err = err; 2232 atomic_set(&wrq->done, 1); 2233 } 2234 if (atomic_read(&wrq->done)) { 2235 wrq->wq.func(&wrq->wq, 2236 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 2237 0, NULL); 2238 } 2239 } 2240 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags); 2241 } 2242 2243 /** 2244 * nilfs_construct_segment - construct a logical segment 2245 * @sb: super block 2246 * 2247 * Return Value: On success, 0 is retured. On errors, one of the following 2248 * negative error code is returned. 2249 * 2250 * %-EROFS - Read only filesystem. 2251 * 2252 * %-EIO - I/O error 2253 * 2254 * %-ENOSPC - No space left on device (only in a panic state). 2255 * 2256 * %-ERESTARTSYS - Interrupted. 2257 * 2258 * %-ENOMEM - Insufficient memory available. 2259 */ 2260 int nilfs_construct_segment(struct super_block *sb) 2261 { 2262 struct nilfs_sb_info *sbi = NILFS_SB(sb); 2263 struct nilfs_sc_info *sci = NILFS_SC(sbi); 2264 struct nilfs_transaction_info *ti; 2265 int err; 2266 2267 if (!sci) 2268 return -EROFS; 2269 2270 /* A call inside transactions causes a deadlock. */ 2271 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC); 2272 2273 err = nilfs_segctor_sync(sci); 2274 return err; 2275 } 2276 2277 /** 2278 * nilfs_construct_dsync_segment - construct a data-only logical segment 2279 * @sb: super block 2280 * @inode: inode whose data blocks should be written out 2281 * @start: start byte offset 2282 * @end: end byte offset (inclusive) 2283 * 2284 * Return Value: On success, 0 is retured. On errors, one of the following 2285 * negative error code is returned. 2286 * 2287 * %-EROFS - Read only filesystem. 2288 * 2289 * %-EIO - I/O error 2290 * 2291 * %-ENOSPC - No space left on device (only in a panic state). 2292 * 2293 * %-ERESTARTSYS - Interrupted. 2294 * 2295 * %-ENOMEM - Insufficient memory available. 2296 */ 2297 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode, 2298 loff_t start, loff_t end) 2299 { 2300 struct nilfs_sb_info *sbi = NILFS_SB(sb); 2301 struct nilfs_sc_info *sci = NILFS_SC(sbi); 2302 struct nilfs_inode_info *ii; 2303 struct nilfs_transaction_info ti; 2304 int err = 0; 2305 2306 if (!sci) 2307 return -EROFS; 2308 2309 nilfs_transaction_lock(sbi, &ti, 0); 2310 2311 ii = NILFS_I(inode); 2312 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) || 2313 nilfs_test_opt(sbi, STRICT_ORDER) || 2314 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2315 nilfs_discontinued(sbi->s_nilfs)) { 2316 nilfs_transaction_unlock(sbi); 2317 err = nilfs_segctor_sync(sci); 2318 return err; 2319 } 2320 2321 spin_lock(&sbi->s_inode_lock); 2322 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) && 2323 !test_bit(NILFS_I_BUSY, &ii->i_state)) { 2324 spin_unlock(&sbi->s_inode_lock); 2325 nilfs_transaction_unlock(sbi); 2326 return 0; 2327 } 2328 spin_unlock(&sbi->s_inode_lock); 2329 sci->sc_dsync_inode = ii; 2330 sci->sc_dsync_start = start; 2331 sci->sc_dsync_end = end; 2332 2333 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC); 2334 2335 nilfs_transaction_unlock(sbi); 2336 return err; 2337 } 2338 2339 #define FLUSH_FILE_BIT (0x1) /* data file only */ 2340 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */ 2341 2342 /** 2343 * nilfs_segctor_accept - record accepted sequence count of log-write requests 2344 * @sci: segment constructor object 2345 */ 2346 static void nilfs_segctor_accept(struct nilfs_sc_info *sci) 2347 { 2348 spin_lock(&sci->sc_state_lock); 2349 sci->sc_seq_accepted = sci->sc_seq_request; 2350 spin_unlock(&sci->sc_state_lock); 2351 del_timer_sync(&sci->sc_timer); 2352 } 2353 2354 /** 2355 * nilfs_segctor_notify - notify the result of request to caller threads 2356 * @sci: segment constructor object 2357 * @mode: mode of log forming 2358 * @err: error code to be notified 2359 */ 2360 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err) 2361 { 2362 /* Clear requests (even when the construction failed) */ 2363 spin_lock(&sci->sc_state_lock); 2364 2365 if (mode == SC_LSEG_SR) { 2366 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT; 2367 sci->sc_seq_done = sci->sc_seq_accepted; 2368 nilfs_segctor_wakeup(sci, err); 2369 sci->sc_flush_request = 0; 2370 } else { 2371 if (mode == SC_FLUSH_FILE) 2372 sci->sc_flush_request &= ~FLUSH_FILE_BIT; 2373 else if (mode == SC_FLUSH_DAT) 2374 sci->sc_flush_request &= ~FLUSH_DAT_BIT; 2375 2376 /* re-enable timer if checkpoint creation was not done */ 2377 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2378 time_before(jiffies, sci->sc_timer.expires)) 2379 add_timer(&sci->sc_timer); 2380 } 2381 spin_unlock(&sci->sc_state_lock); 2382 } 2383 2384 /** 2385 * nilfs_segctor_construct - form logs and write them to disk 2386 * @sci: segment constructor object 2387 * @mode: mode of log forming 2388 */ 2389 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode) 2390 { 2391 struct nilfs_sb_info *sbi = sci->sc_sbi; 2392 struct the_nilfs *nilfs = sbi->s_nilfs; 2393 struct nilfs_super_block **sbp; 2394 int err = 0; 2395 2396 nilfs_segctor_accept(sci); 2397 2398 if (nilfs_discontinued(nilfs)) 2399 mode = SC_LSEG_SR; 2400 if (!nilfs_segctor_confirm(sci)) 2401 err = nilfs_segctor_do_construct(sci, mode); 2402 2403 if (likely(!err)) { 2404 if (mode != SC_FLUSH_DAT) 2405 atomic_set(&nilfs->ns_ndirtyblks, 0); 2406 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) && 2407 nilfs_discontinued(nilfs)) { 2408 down_write(&nilfs->ns_sem); 2409 err = -EIO; 2410 sbp = nilfs_prepare_super(sbi, 2411 nilfs_sb_will_flip(nilfs)); 2412 if (likely(sbp)) { 2413 nilfs_set_log_cursor(sbp[0], nilfs); 2414 err = nilfs_commit_super(sbi, NILFS_SB_COMMIT); 2415 } 2416 up_write(&nilfs->ns_sem); 2417 } 2418 } 2419 2420 nilfs_segctor_notify(sci, mode, err); 2421 return err; 2422 } 2423 2424 static void nilfs_construction_timeout(unsigned long data) 2425 { 2426 struct task_struct *p = (struct task_struct *)data; 2427 wake_up_process(p); 2428 } 2429 2430 static void 2431 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head) 2432 { 2433 struct nilfs_inode_info *ii, *n; 2434 2435 list_for_each_entry_safe(ii, n, head, i_dirty) { 2436 if (!test_bit(NILFS_I_UPDATED, &ii->i_state)) 2437 continue; 2438 list_del_init(&ii->i_dirty); 2439 iput(&ii->vfs_inode); 2440 } 2441 } 2442 2443 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv, 2444 void **kbufs) 2445 { 2446 struct nilfs_sb_info *sbi = NILFS_SB(sb); 2447 struct nilfs_sc_info *sci = NILFS_SC(sbi); 2448 struct the_nilfs *nilfs = sbi->s_nilfs; 2449 struct nilfs_transaction_info ti; 2450 int err; 2451 2452 if (unlikely(!sci)) 2453 return -EROFS; 2454 2455 nilfs_transaction_lock(sbi, &ti, 1); 2456 2457 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat); 2458 if (unlikely(err)) 2459 goto out_unlock; 2460 2461 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs); 2462 if (unlikely(err)) { 2463 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat); 2464 goto out_unlock; 2465 } 2466 2467 sci->sc_freesegs = kbufs[4]; 2468 sci->sc_nfreesegs = argv[4].v_nmembs; 2469 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes); 2470 2471 for (;;) { 2472 err = nilfs_segctor_construct(sci, SC_LSEG_SR); 2473 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes); 2474 2475 if (likely(!err)) 2476 break; 2477 2478 nilfs_warning(sb, __func__, 2479 "segment construction failed. (err=%d)", err); 2480 set_current_state(TASK_INTERRUPTIBLE); 2481 schedule_timeout(sci->sc_interval); 2482 } 2483 if (nilfs_test_opt(sbi, DISCARD)) { 2484 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs, 2485 sci->sc_nfreesegs); 2486 if (ret) { 2487 printk(KERN_WARNING 2488 "NILFS warning: error %d on discard request, " 2489 "turning discards off for the device\n", ret); 2490 nilfs_clear_opt(sbi, DISCARD); 2491 } 2492 } 2493 2494 out_unlock: 2495 sci->sc_freesegs = NULL; 2496 sci->sc_nfreesegs = 0; 2497 nilfs_mdt_clear_shadow_map(nilfs->ns_dat); 2498 nilfs_transaction_unlock(sbi); 2499 return err; 2500 } 2501 2502 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode) 2503 { 2504 struct nilfs_sb_info *sbi = sci->sc_sbi; 2505 struct nilfs_transaction_info ti; 2506 2507 nilfs_transaction_lock(sbi, &ti, 0); 2508 nilfs_segctor_construct(sci, mode); 2509 2510 /* 2511 * Unclosed segment should be retried. We do this using sc_timer. 2512 * Timeout of sc_timer will invoke complete construction which leads 2513 * to close the current logical segment. 2514 */ 2515 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) 2516 nilfs_segctor_start_timer(sci); 2517 2518 nilfs_transaction_unlock(sbi); 2519 } 2520 2521 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci) 2522 { 2523 int mode = 0; 2524 int err; 2525 2526 spin_lock(&sci->sc_state_lock); 2527 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ? 2528 SC_FLUSH_DAT : SC_FLUSH_FILE; 2529 spin_unlock(&sci->sc_state_lock); 2530 2531 if (mode) { 2532 err = nilfs_segctor_do_construct(sci, mode); 2533 2534 spin_lock(&sci->sc_state_lock); 2535 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ? 2536 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT; 2537 spin_unlock(&sci->sc_state_lock); 2538 } 2539 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 2540 } 2541 2542 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci) 2543 { 2544 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2545 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) { 2546 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT)) 2547 return SC_FLUSH_FILE; 2548 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT)) 2549 return SC_FLUSH_DAT; 2550 } 2551 return SC_LSEG_SR; 2552 } 2553 2554 /** 2555 * nilfs_segctor_thread - main loop of the segment constructor thread. 2556 * @arg: pointer to a struct nilfs_sc_info. 2557 * 2558 * nilfs_segctor_thread() initializes a timer and serves as a daemon 2559 * to execute segment constructions. 2560 */ 2561 static int nilfs_segctor_thread(void *arg) 2562 { 2563 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg; 2564 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs; 2565 int timeout = 0; 2566 2567 sci->sc_timer.data = (unsigned long)current; 2568 sci->sc_timer.function = nilfs_construction_timeout; 2569 2570 /* start sync. */ 2571 sci->sc_task = current; 2572 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */ 2573 printk(KERN_INFO 2574 "segctord starting. Construction interval = %lu seconds, " 2575 "CP frequency < %lu seconds\n", 2576 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ); 2577 2578 spin_lock(&sci->sc_state_lock); 2579 loop: 2580 for (;;) { 2581 int mode; 2582 2583 if (sci->sc_state & NILFS_SEGCTOR_QUIT) 2584 goto end_thread; 2585 2586 if (timeout || sci->sc_seq_request != sci->sc_seq_done) 2587 mode = SC_LSEG_SR; 2588 else if (!sci->sc_flush_request) 2589 break; 2590 else 2591 mode = nilfs_segctor_flush_mode(sci); 2592 2593 spin_unlock(&sci->sc_state_lock); 2594 nilfs_segctor_thread_construct(sci, mode); 2595 spin_lock(&sci->sc_state_lock); 2596 timeout = 0; 2597 } 2598 2599 2600 if (freezing(current)) { 2601 spin_unlock(&sci->sc_state_lock); 2602 refrigerator(); 2603 spin_lock(&sci->sc_state_lock); 2604 } else { 2605 DEFINE_WAIT(wait); 2606 int should_sleep = 1; 2607 2608 prepare_to_wait(&sci->sc_wait_daemon, &wait, 2609 TASK_INTERRUPTIBLE); 2610 2611 if (sci->sc_seq_request != sci->sc_seq_done) 2612 should_sleep = 0; 2613 else if (sci->sc_flush_request) 2614 should_sleep = 0; 2615 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT) 2616 should_sleep = time_before(jiffies, 2617 sci->sc_timer.expires); 2618 2619 if (should_sleep) { 2620 spin_unlock(&sci->sc_state_lock); 2621 schedule(); 2622 spin_lock(&sci->sc_state_lock); 2623 } 2624 finish_wait(&sci->sc_wait_daemon, &wait); 2625 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2626 time_after_eq(jiffies, sci->sc_timer.expires)); 2627 2628 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs)) 2629 set_nilfs_discontinued(nilfs); 2630 } 2631 goto loop; 2632 2633 end_thread: 2634 spin_unlock(&sci->sc_state_lock); 2635 2636 /* end sync. */ 2637 sci->sc_task = NULL; 2638 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */ 2639 return 0; 2640 } 2641 2642 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci) 2643 { 2644 struct task_struct *t; 2645 2646 t = kthread_run(nilfs_segctor_thread, sci, "segctord"); 2647 if (IS_ERR(t)) { 2648 int err = PTR_ERR(t); 2649 2650 printk(KERN_ERR "NILFS: error %d creating segctord thread\n", 2651 err); 2652 return err; 2653 } 2654 wait_event(sci->sc_wait_task, sci->sc_task != NULL); 2655 return 0; 2656 } 2657 2658 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci) 2659 __acquires(&sci->sc_state_lock) 2660 __releases(&sci->sc_state_lock) 2661 { 2662 sci->sc_state |= NILFS_SEGCTOR_QUIT; 2663 2664 while (sci->sc_task) { 2665 wake_up(&sci->sc_wait_daemon); 2666 spin_unlock(&sci->sc_state_lock); 2667 wait_event(sci->sc_wait_task, sci->sc_task == NULL); 2668 spin_lock(&sci->sc_state_lock); 2669 } 2670 } 2671 2672 /* 2673 * Setup & clean-up functions 2674 */ 2675 static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi, 2676 struct nilfs_root *root) 2677 { 2678 struct nilfs_sc_info *sci; 2679 2680 sci = kzalloc(sizeof(*sci), GFP_KERNEL); 2681 if (!sci) 2682 return NULL; 2683 2684 sci->sc_sbi = sbi; 2685 sci->sc_super = sbi->s_super; 2686 2687 nilfs_get_root(root); 2688 sci->sc_root = root; 2689 2690 init_waitqueue_head(&sci->sc_wait_request); 2691 init_waitqueue_head(&sci->sc_wait_daemon); 2692 init_waitqueue_head(&sci->sc_wait_task); 2693 spin_lock_init(&sci->sc_state_lock); 2694 INIT_LIST_HEAD(&sci->sc_dirty_files); 2695 INIT_LIST_HEAD(&sci->sc_segbufs); 2696 INIT_LIST_HEAD(&sci->sc_write_logs); 2697 INIT_LIST_HEAD(&sci->sc_gc_inodes); 2698 INIT_LIST_HEAD(&sci->sc_copied_buffers); 2699 init_timer(&sci->sc_timer); 2700 2701 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT; 2702 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ; 2703 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK; 2704 2705 if (sbi->s_interval) 2706 sci->sc_interval = sbi->s_interval; 2707 if (sbi->s_watermark) 2708 sci->sc_watermark = sbi->s_watermark; 2709 return sci; 2710 } 2711 2712 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci) 2713 { 2714 int ret, retrycount = NILFS_SC_CLEANUP_RETRY; 2715 2716 /* The segctord thread was stopped and its timer was removed. 2717 But some tasks remain. */ 2718 do { 2719 struct nilfs_sb_info *sbi = sci->sc_sbi; 2720 struct nilfs_transaction_info ti; 2721 2722 nilfs_transaction_lock(sbi, &ti, 0); 2723 ret = nilfs_segctor_construct(sci, SC_LSEG_SR); 2724 nilfs_transaction_unlock(sbi); 2725 2726 } while (ret && retrycount-- > 0); 2727 } 2728 2729 /** 2730 * nilfs_segctor_destroy - destroy the segment constructor. 2731 * @sci: nilfs_sc_info 2732 * 2733 * nilfs_segctor_destroy() kills the segctord thread and frees 2734 * the nilfs_sc_info struct. 2735 * Caller must hold the segment semaphore. 2736 */ 2737 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci) 2738 { 2739 struct nilfs_sb_info *sbi = sci->sc_sbi; 2740 int flag; 2741 2742 up_write(&sbi->s_nilfs->ns_segctor_sem); 2743 2744 spin_lock(&sci->sc_state_lock); 2745 nilfs_segctor_kill_thread(sci); 2746 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request 2747 || sci->sc_seq_request != sci->sc_seq_done); 2748 spin_unlock(&sci->sc_state_lock); 2749 2750 if (flag || !nilfs_segctor_confirm(sci)) 2751 nilfs_segctor_write_out(sci); 2752 2753 WARN_ON(!list_empty(&sci->sc_copied_buffers)); 2754 2755 if (!list_empty(&sci->sc_dirty_files)) { 2756 nilfs_warning(sbi->s_super, __func__, 2757 "dirty file(s) after the final construction\n"); 2758 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1); 2759 } 2760 2761 WARN_ON(!list_empty(&sci->sc_segbufs)); 2762 WARN_ON(!list_empty(&sci->sc_write_logs)); 2763 2764 nilfs_put_root(sci->sc_root); 2765 2766 down_write(&sbi->s_nilfs->ns_segctor_sem); 2767 2768 del_timer_sync(&sci->sc_timer); 2769 kfree(sci); 2770 } 2771 2772 /** 2773 * nilfs_attach_segment_constructor - attach a segment constructor 2774 * @sbi: nilfs_sb_info 2775 * @root: root object of the current filesystem tree 2776 * 2777 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info, 2778 * initializes it, and starts the segment constructor. 2779 * 2780 * Return Value: On success, 0 is returned. On error, one of the following 2781 * negative error code is returned. 2782 * 2783 * %-ENOMEM - Insufficient memory available. 2784 */ 2785 int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi, 2786 struct nilfs_root *root) 2787 { 2788 int err; 2789 2790 if (NILFS_SC(sbi)) { 2791 /* 2792 * This happens if the filesystem was remounted 2793 * read/write after nilfs_error degenerated it into a 2794 * read-only mount. 2795 */ 2796 nilfs_detach_segment_constructor(sbi); 2797 } 2798 2799 sbi->s_sc_info = nilfs_segctor_new(sbi, root); 2800 if (!sbi->s_sc_info) 2801 return -ENOMEM; 2802 2803 err = nilfs_segctor_start_thread(NILFS_SC(sbi)); 2804 if (err) { 2805 kfree(sbi->s_sc_info); 2806 sbi->s_sc_info = NULL; 2807 } 2808 return err; 2809 } 2810 2811 /** 2812 * nilfs_detach_segment_constructor - destroy the segment constructor 2813 * @sbi: nilfs_sb_info 2814 * 2815 * nilfs_detach_segment_constructor() kills the segment constructor daemon, 2816 * frees the struct nilfs_sc_info, and destroy the dirty file list. 2817 */ 2818 void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi) 2819 { 2820 struct the_nilfs *nilfs = sbi->s_nilfs; 2821 LIST_HEAD(garbage_list); 2822 2823 down_write(&nilfs->ns_segctor_sem); 2824 if (NILFS_SC(sbi)) { 2825 nilfs_segctor_destroy(NILFS_SC(sbi)); 2826 sbi->s_sc_info = NULL; 2827 } 2828 2829 /* Force to free the list of dirty files */ 2830 spin_lock(&sbi->s_inode_lock); 2831 if (!list_empty(&sbi->s_dirty_files)) { 2832 list_splice_init(&sbi->s_dirty_files, &garbage_list); 2833 nilfs_warning(sbi->s_super, __func__, 2834 "Non empty dirty list after the last " 2835 "segment construction\n"); 2836 } 2837 spin_unlock(&sbi->s_inode_lock); 2838 up_write(&nilfs->ns_segctor_sem); 2839 2840 nilfs_dispose_list(sbi, &garbage_list, 1); 2841 } 2842