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 lock_page(page); 659 if (!page_has_buffers(page)) 660 create_empty_buffers(page, 1 << inode->i_blkbits, 0); 661 unlock_page(page); 662 663 bh = head = page_buffers(page); 664 do { 665 if (!buffer_dirty(bh)) 666 continue; 667 get_bh(bh); 668 list_add_tail(&bh->b_assoc_buffers, listp); 669 ndirties++; 670 if (unlikely(ndirties >= nlimit)) { 671 pagevec_release(&pvec); 672 cond_resched(); 673 return ndirties; 674 } 675 } while (bh = bh->b_this_page, bh != head); 676 } 677 pagevec_release(&pvec); 678 cond_resched(); 679 goto repeat; 680 } 681 682 static void nilfs_lookup_dirty_node_buffers(struct inode *inode, 683 struct list_head *listp) 684 { 685 struct nilfs_inode_info *ii = NILFS_I(inode); 686 struct address_space *mapping = &ii->i_btnode_cache; 687 struct pagevec pvec; 688 struct buffer_head *bh, *head; 689 unsigned int i; 690 pgoff_t index = 0; 691 692 pagevec_init(&pvec, 0); 693 694 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 695 PAGEVEC_SIZE)) { 696 for (i = 0; i < pagevec_count(&pvec); i++) { 697 bh = head = page_buffers(pvec.pages[i]); 698 do { 699 if (buffer_dirty(bh)) { 700 get_bh(bh); 701 list_add_tail(&bh->b_assoc_buffers, 702 listp); 703 } 704 bh = bh->b_this_page; 705 } while (bh != head); 706 } 707 pagevec_release(&pvec); 708 cond_resched(); 709 } 710 } 711 712 static void nilfs_dispose_list(struct the_nilfs *nilfs, 713 struct list_head *head, int force) 714 { 715 struct nilfs_inode_info *ii, *n; 716 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii; 717 unsigned nv = 0; 718 719 while (!list_empty(head)) { 720 spin_lock(&nilfs->ns_inode_lock); 721 list_for_each_entry_safe(ii, n, head, i_dirty) { 722 list_del_init(&ii->i_dirty); 723 if (force) { 724 if (unlikely(ii->i_bh)) { 725 brelse(ii->i_bh); 726 ii->i_bh = NULL; 727 } 728 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) { 729 set_bit(NILFS_I_QUEUED, &ii->i_state); 730 list_add_tail(&ii->i_dirty, 731 &nilfs->ns_dirty_files); 732 continue; 733 } 734 ivec[nv++] = ii; 735 if (nv == SC_N_INODEVEC) 736 break; 737 } 738 spin_unlock(&nilfs->ns_inode_lock); 739 740 for (pii = ivec; nv > 0; pii++, nv--) 741 iput(&(*pii)->vfs_inode); 742 } 743 } 744 745 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs, 746 struct nilfs_root *root) 747 { 748 int ret = 0; 749 750 if (nilfs_mdt_fetch_dirty(root->ifile)) 751 ret++; 752 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile)) 753 ret++; 754 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile)) 755 ret++; 756 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat)) 757 ret++; 758 return ret; 759 } 760 761 static int nilfs_segctor_clean(struct nilfs_sc_info *sci) 762 { 763 return list_empty(&sci->sc_dirty_files) && 764 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) && 765 sci->sc_nfreesegs == 0 && 766 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes)); 767 } 768 769 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci) 770 { 771 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 772 int ret = 0; 773 774 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 775 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 776 777 spin_lock(&nilfs->ns_inode_lock); 778 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci)) 779 ret++; 780 781 spin_unlock(&nilfs->ns_inode_lock); 782 return ret; 783 } 784 785 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci) 786 { 787 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 788 789 nilfs_mdt_clear_dirty(sci->sc_root->ifile); 790 nilfs_mdt_clear_dirty(nilfs->ns_cpfile); 791 nilfs_mdt_clear_dirty(nilfs->ns_sufile); 792 nilfs_mdt_clear_dirty(nilfs->ns_dat); 793 } 794 795 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci) 796 { 797 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 798 struct buffer_head *bh_cp; 799 struct nilfs_checkpoint *raw_cp; 800 int err; 801 802 /* XXX: this interface will be changed */ 803 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1, 804 &raw_cp, &bh_cp); 805 if (likely(!err)) { 806 /* The following code is duplicated with cpfile. But, it is 807 needed to collect the checkpoint even if it was not newly 808 created */ 809 mark_buffer_dirty(bh_cp); 810 nilfs_mdt_mark_dirty(nilfs->ns_cpfile); 811 nilfs_cpfile_put_checkpoint( 812 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 813 } else 814 WARN_ON(err == -EINVAL || err == -ENOENT); 815 816 return err; 817 } 818 819 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci) 820 { 821 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 822 struct buffer_head *bh_cp; 823 struct nilfs_checkpoint *raw_cp; 824 int err; 825 826 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0, 827 &raw_cp, &bh_cp); 828 if (unlikely(err)) { 829 WARN_ON(err == -EINVAL || err == -ENOENT); 830 goto failed_ibh; 831 } 832 raw_cp->cp_snapshot_list.ssl_next = 0; 833 raw_cp->cp_snapshot_list.ssl_prev = 0; 834 raw_cp->cp_inodes_count = 835 cpu_to_le64(atomic_read(&sci->sc_root->inodes_count)); 836 raw_cp->cp_blocks_count = 837 cpu_to_le64(atomic_read(&sci->sc_root->blocks_count)); 838 raw_cp->cp_nblk_inc = 839 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc); 840 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime); 841 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno); 842 843 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 844 nilfs_checkpoint_clear_minor(raw_cp); 845 else 846 nilfs_checkpoint_set_minor(raw_cp); 847 848 nilfs_write_inode_common(sci->sc_root->ifile, 849 &raw_cp->cp_ifile_inode, 1); 850 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 851 return 0; 852 853 failed_ibh: 854 return err; 855 } 856 857 static void nilfs_fill_in_file_bmap(struct inode *ifile, 858 struct nilfs_inode_info *ii) 859 860 { 861 struct buffer_head *ibh; 862 struct nilfs_inode *raw_inode; 863 864 if (test_bit(NILFS_I_BMAP, &ii->i_state)) { 865 ibh = ii->i_bh; 866 BUG_ON(!ibh); 867 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino, 868 ibh); 869 nilfs_bmap_write(ii->i_bmap, raw_inode); 870 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh); 871 } 872 } 873 874 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci) 875 { 876 struct nilfs_inode_info *ii; 877 878 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) { 879 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii); 880 set_bit(NILFS_I_COLLECTED, &ii->i_state); 881 } 882 } 883 884 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci, 885 struct the_nilfs *nilfs) 886 { 887 struct buffer_head *bh_sr; 888 struct nilfs_super_root *raw_sr; 889 unsigned isz, srsz; 890 891 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root; 892 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 893 isz = nilfs->ns_inode_size; 894 srsz = NILFS_SR_BYTES(isz); 895 896 raw_sr->sr_bytes = cpu_to_le16(srsz); 897 raw_sr->sr_nongc_ctime 898 = cpu_to_le64(nilfs_doing_gc() ? 899 nilfs->ns_nongc_ctime : sci->sc_seg_ctime); 900 raw_sr->sr_flags = 0; 901 902 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr + 903 NILFS_SR_DAT_OFFSET(isz), 1); 904 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr + 905 NILFS_SR_CPFILE_OFFSET(isz), 1); 906 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr + 907 NILFS_SR_SUFILE_OFFSET(isz), 1); 908 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz); 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_first_entry(listp, 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 inode = bh->b_page->mapping->host; 1504 1505 if (mode == SC_LSEG_DSYNC) 1506 sc_op = &nilfs_sc_dsync_ops; 1507 else if (ino == NILFS_DAT_INO) 1508 sc_op = &nilfs_sc_dat_ops; 1509 else /* file blocks */ 1510 sc_op = &nilfs_sc_file_ops; 1511 } 1512 bh_org = bh; 1513 get_bh(bh_org); 1514 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr, 1515 &binfo); 1516 if (bh != bh_org) 1517 nilfs_list_replace_buffer(bh_org, bh); 1518 brelse(bh_org); 1519 if (unlikely(err)) 1520 goto failed_bmap; 1521 1522 if (ndatablk > 0) 1523 sc_op->write_data_binfo(sci, &ssp, &binfo); 1524 else 1525 sc_op->write_node_binfo(sci, &ssp, &binfo); 1526 1527 blocknr++; 1528 if (--nblocks == 0) { 1529 finfo = NULL; 1530 if (--nfinfo == 0) 1531 break; 1532 } else if (ndatablk > 0) 1533 ndatablk--; 1534 } 1535 out: 1536 return 0; 1537 1538 failed_bmap: 1539 return err; 1540 } 1541 1542 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode) 1543 { 1544 struct nilfs_segment_buffer *segbuf; 1545 int err; 1546 1547 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1548 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode); 1549 if (unlikely(err)) 1550 return err; 1551 nilfs_segbuf_fill_in_segsum(segbuf); 1552 } 1553 return 0; 1554 } 1555 1556 static void nilfs_begin_page_io(struct page *page) 1557 { 1558 if (!page || PageWriteback(page)) 1559 /* For split b-tree node pages, this function may be called 1560 twice. We ignore the 2nd or later calls by this check. */ 1561 return; 1562 1563 lock_page(page); 1564 clear_page_dirty_for_io(page); 1565 set_page_writeback(page); 1566 unlock_page(page); 1567 } 1568 1569 static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) 1570 { 1571 struct nilfs_segment_buffer *segbuf; 1572 struct page *bd_page = NULL, *fs_page = NULL; 1573 1574 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1575 struct buffer_head *bh; 1576 1577 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1578 b_assoc_buffers) { 1579 if (bh->b_page != bd_page) { 1580 if (bd_page) { 1581 lock_page(bd_page); 1582 clear_page_dirty_for_io(bd_page); 1583 set_page_writeback(bd_page); 1584 unlock_page(bd_page); 1585 } 1586 bd_page = bh->b_page; 1587 } 1588 } 1589 1590 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1591 b_assoc_buffers) { 1592 if (bh == segbuf->sb_super_root) { 1593 if (bh->b_page != bd_page) { 1594 lock_page(bd_page); 1595 clear_page_dirty_for_io(bd_page); 1596 set_page_writeback(bd_page); 1597 unlock_page(bd_page); 1598 bd_page = bh->b_page; 1599 } 1600 break; 1601 } 1602 if (bh->b_page != fs_page) { 1603 nilfs_begin_page_io(fs_page); 1604 fs_page = bh->b_page; 1605 } 1606 } 1607 } 1608 if (bd_page) { 1609 lock_page(bd_page); 1610 clear_page_dirty_for_io(bd_page); 1611 set_page_writeback(bd_page); 1612 unlock_page(bd_page); 1613 } 1614 nilfs_begin_page_io(fs_page); 1615 } 1616 1617 static int nilfs_segctor_write(struct nilfs_sc_info *sci, 1618 struct the_nilfs *nilfs) 1619 { 1620 int ret; 1621 1622 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs); 1623 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs); 1624 return ret; 1625 } 1626 1627 static void nilfs_end_page_io(struct page *page, int err) 1628 { 1629 if (!page) 1630 return; 1631 1632 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) { 1633 /* 1634 * For b-tree node pages, this function may be called twice 1635 * or more because they might be split in a segment. 1636 */ 1637 if (PageDirty(page)) { 1638 /* 1639 * For pages holding split b-tree node buffers, dirty 1640 * flag on the buffers may be cleared discretely. 1641 * In that case, the page is once redirtied for 1642 * remaining buffers, and it must be cancelled if 1643 * all the buffers get cleaned later. 1644 */ 1645 lock_page(page); 1646 if (nilfs_page_buffers_clean(page)) 1647 __nilfs_clear_page_dirty(page); 1648 unlock_page(page); 1649 } 1650 return; 1651 } 1652 1653 if (!err) { 1654 if (!nilfs_page_buffers_clean(page)) 1655 __set_page_dirty_nobuffers(page); 1656 ClearPageError(page); 1657 } else { 1658 __set_page_dirty_nobuffers(page); 1659 SetPageError(page); 1660 } 1661 1662 end_page_writeback(page); 1663 } 1664 1665 static void nilfs_abort_logs(struct list_head *logs, int err) 1666 { 1667 struct nilfs_segment_buffer *segbuf; 1668 struct page *bd_page = NULL, *fs_page = NULL; 1669 struct buffer_head *bh; 1670 1671 if (list_empty(logs)) 1672 return; 1673 1674 list_for_each_entry(segbuf, logs, sb_list) { 1675 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1676 b_assoc_buffers) { 1677 if (bh->b_page != bd_page) { 1678 if (bd_page) 1679 end_page_writeback(bd_page); 1680 bd_page = bh->b_page; 1681 } 1682 } 1683 1684 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1685 b_assoc_buffers) { 1686 if (bh == segbuf->sb_super_root) { 1687 if (bh->b_page != bd_page) { 1688 end_page_writeback(bd_page); 1689 bd_page = bh->b_page; 1690 } 1691 break; 1692 } 1693 if (bh->b_page != fs_page) { 1694 nilfs_end_page_io(fs_page, err); 1695 fs_page = bh->b_page; 1696 } 1697 } 1698 } 1699 if (bd_page) 1700 end_page_writeback(bd_page); 1701 1702 nilfs_end_page_io(fs_page, err); 1703 } 1704 1705 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci, 1706 struct the_nilfs *nilfs, int err) 1707 { 1708 LIST_HEAD(logs); 1709 int ret; 1710 1711 list_splice_tail_init(&sci->sc_write_logs, &logs); 1712 ret = nilfs_wait_on_logs(&logs); 1713 nilfs_abort_logs(&logs, ret ? : err); 1714 1715 list_splice_tail_init(&sci->sc_segbufs, &logs); 1716 nilfs_cancel_segusage(&logs, nilfs->ns_sufile); 1717 nilfs_free_incomplete_logs(&logs, nilfs); 1718 1719 if (sci->sc_stage.flags & NILFS_CF_SUFREED) { 1720 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1721 sci->sc_freesegs, 1722 sci->sc_nfreesegs, 1723 NULL); 1724 WARN_ON(ret); /* do not happen */ 1725 } 1726 1727 nilfs_destroy_logs(&logs); 1728 } 1729 1730 static void nilfs_set_next_segment(struct the_nilfs *nilfs, 1731 struct nilfs_segment_buffer *segbuf) 1732 { 1733 nilfs->ns_segnum = segbuf->sb_segnum; 1734 nilfs->ns_nextnum = segbuf->sb_nextnum; 1735 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start 1736 + segbuf->sb_sum.nblocks; 1737 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq; 1738 nilfs->ns_ctime = segbuf->sb_sum.ctime; 1739 } 1740 1741 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) 1742 { 1743 struct nilfs_segment_buffer *segbuf; 1744 struct page *bd_page = NULL, *fs_page = NULL; 1745 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1746 int update_sr = false; 1747 1748 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) { 1749 struct buffer_head *bh; 1750 1751 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1752 b_assoc_buffers) { 1753 set_buffer_uptodate(bh); 1754 clear_buffer_dirty(bh); 1755 if (bh->b_page != bd_page) { 1756 if (bd_page) 1757 end_page_writeback(bd_page); 1758 bd_page = bh->b_page; 1759 } 1760 } 1761 /* 1762 * We assume that the buffers which belong to the same page 1763 * continue over the buffer list. 1764 * Under this assumption, the last BHs of pages is 1765 * identifiable by the discontinuity of bh->b_page 1766 * (page != fs_page). 1767 * 1768 * For B-tree node blocks, however, this assumption is not 1769 * guaranteed. The cleanup code of B-tree node pages needs 1770 * special care. 1771 */ 1772 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1773 b_assoc_buffers) { 1774 set_buffer_uptodate(bh); 1775 clear_buffer_dirty(bh); 1776 clear_buffer_delay(bh); 1777 clear_buffer_nilfs_volatile(bh); 1778 clear_buffer_nilfs_redirected(bh); 1779 if (bh == segbuf->sb_super_root) { 1780 if (bh->b_page != bd_page) { 1781 end_page_writeback(bd_page); 1782 bd_page = bh->b_page; 1783 } 1784 update_sr = true; 1785 break; 1786 } 1787 if (bh->b_page != fs_page) { 1788 nilfs_end_page_io(fs_page, 0); 1789 fs_page = bh->b_page; 1790 } 1791 } 1792 1793 if (!nilfs_segbuf_simplex(segbuf)) { 1794 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) { 1795 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1796 sci->sc_lseg_stime = jiffies; 1797 } 1798 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND) 1799 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1800 } 1801 } 1802 /* 1803 * Since pages may continue over multiple segment buffers, 1804 * end of the last page must be checked outside of the loop. 1805 */ 1806 if (bd_page) 1807 end_page_writeback(bd_page); 1808 1809 nilfs_end_page_io(fs_page, 0); 1810 1811 nilfs_drop_collected_inodes(&sci->sc_dirty_files); 1812 1813 if (nilfs_doing_gc()) 1814 nilfs_drop_collected_inodes(&sci->sc_gc_inodes); 1815 else 1816 nilfs->ns_nongc_ctime = sci->sc_seg_ctime; 1817 1818 sci->sc_nblk_inc += sci->sc_nblk_this_inc; 1819 1820 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1821 nilfs_set_next_segment(nilfs, segbuf); 1822 1823 if (update_sr) { 1824 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start, 1825 segbuf->sb_sum.seg_seq, nilfs->ns_cno++); 1826 1827 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 1828 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags); 1829 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1830 nilfs_segctor_clear_metadata_dirty(sci); 1831 } else 1832 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1833 } 1834 1835 static int nilfs_segctor_wait(struct nilfs_sc_info *sci) 1836 { 1837 int ret; 1838 1839 ret = nilfs_wait_on_logs(&sci->sc_write_logs); 1840 if (!ret) { 1841 nilfs_segctor_complete_write(sci); 1842 nilfs_destroy_logs(&sci->sc_write_logs); 1843 } 1844 return ret; 1845 } 1846 1847 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci, 1848 struct the_nilfs *nilfs) 1849 { 1850 struct nilfs_inode_info *ii, *n; 1851 struct inode *ifile = sci->sc_root->ifile; 1852 1853 spin_lock(&nilfs->ns_inode_lock); 1854 retry: 1855 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) { 1856 if (!ii->i_bh) { 1857 struct buffer_head *ibh; 1858 int err; 1859 1860 spin_unlock(&nilfs->ns_inode_lock); 1861 err = nilfs_ifile_get_inode_block( 1862 ifile, ii->vfs_inode.i_ino, &ibh); 1863 if (unlikely(err)) { 1864 nilfs_warning(sci->sc_super, __func__, 1865 "failed to get inode block.\n"); 1866 return err; 1867 } 1868 mark_buffer_dirty(ibh); 1869 nilfs_mdt_mark_dirty(ifile); 1870 spin_lock(&nilfs->ns_inode_lock); 1871 if (likely(!ii->i_bh)) 1872 ii->i_bh = ibh; 1873 else 1874 brelse(ibh); 1875 goto retry; 1876 } 1877 1878 clear_bit(NILFS_I_QUEUED, &ii->i_state); 1879 set_bit(NILFS_I_BUSY, &ii->i_state); 1880 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files); 1881 } 1882 spin_unlock(&nilfs->ns_inode_lock); 1883 1884 return 0; 1885 } 1886 1887 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci, 1888 struct the_nilfs *nilfs) 1889 { 1890 struct nilfs_transaction_info *ti = current->journal_info; 1891 struct nilfs_inode_info *ii, *n; 1892 1893 spin_lock(&nilfs->ns_inode_lock); 1894 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) { 1895 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) || 1896 test_bit(NILFS_I_DIRTY, &ii->i_state)) 1897 continue; 1898 1899 clear_bit(NILFS_I_BUSY, &ii->i_state); 1900 brelse(ii->i_bh); 1901 ii->i_bh = NULL; 1902 list_move_tail(&ii->i_dirty, &ti->ti_garbage); 1903 } 1904 spin_unlock(&nilfs->ns_inode_lock); 1905 } 1906 1907 /* 1908 * Main procedure of segment constructor 1909 */ 1910 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) 1911 { 1912 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1913 int err; 1914 1915 sci->sc_stage.scnt = NILFS_ST_INIT; 1916 sci->sc_cno = nilfs->ns_cno; 1917 1918 err = nilfs_segctor_collect_dirty_files(sci, nilfs); 1919 if (unlikely(err)) 1920 goto out; 1921 1922 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 1923 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 1924 1925 if (nilfs_segctor_clean(sci)) 1926 goto out; 1927 1928 do { 1929 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK; 1930 1931 err = nilfs_segctor_begin_construction(sci, nilfs); 1932 if (unlikely(err)) 1933 goto out; 1934 1935 /* Update time stamp */ 1936 sci->sc_seg_ctime = get_seconds(); 1937 1938 err = nilfs_segctor_collect(sci, nilfs, mode); 1939 if (unlikely(err)) 1940 goto failed; 1941 1942 /* Avoid empty segment */ 1943 if (sci->sc_stage.scnt == NILFS_ST_DONE && 1944 nilfs_segbuf_empty(sci->sc_curseg)) { 1945 nilfs_segctor_abort_construction(sci, nilfs, 1); 1946 goto out; 1947 } 1948 1949 err = nilfs_segctor_assign(sci, mode); 1950 if (unlikely(err)) 1951 goto failed; 1952 1953 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 1954 nilfs_segctor_fill_in_file_bmap(sci); 1955 1956 if (mode == SC_LSEG_SR && 1957 sci->sc_stage.scnt >= NILFS_ST_CPFILE) { 1958 err = nilfs_segctor_fill_in_checkpoint(sci); 1959 if (unlikely(err)) 1960 goto failed_to_write; 1961 1962 nilfs_segctor_fill_in_super_root(sci, nilfs); 1963 } 1964 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile); 1965 1966 /* Write partial segments */ 1967 nilfs_segctor_prepare_write(sci); 1968 1969 nilfs_add_checksums_on_logs(&sci->sc_segbufs, 1970 nilfs->ns_crc_seed); 1971 1972 err = nilfs_segctor_write(sci, nilfs); 1973 if (unlikely(err)) 1974 goto failed_to_write; 1975 1976 if (sci->sc_stage.scnt == NILFS_ST_DONE || 1977 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) { 1978 /* 1979 * At this point, we avoid double buffering 1980 * for blocksize < pagesize because page dirty 1981 * flag is turned off during write and dirty 1982 * buffers are not properly collected for 1983 * pages crossing over segments. 1984 */ 1985 err = nilfs_segctor_wait(sci); 1986 if (err) 1987 goto failed_to_write; 1988 } 1989 } while (sci->sc_stage.scnt != NILFS_ST_DONE); 1990 1991 out: 1992 nilfs_segctor_drop_written_files(sci, nilfs); 1993 return err; 1994 1995 failed_to_write: 1996 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 1997 nilfs_redirty_inodes(&sci->sc_dirty_files); 1998 1999 failed: 2000 if (nilfs_doing_gc()) 2001 nilfs_redirty_inodes(&sci->sc_gc_inodes); 2002 nilfs_segctor_abort_construction(sci, nilfs, err); 2003 goto out; 2004 } 2005 2006 /** 2007 * nilfs_segctor_start_timer - set timer of background write 2008 * @sci: nilfs_sc_info 2009 * 2010 * If the timer has already been set, it ignores the new request. 2011 * This function MUST be called within a section locking the segment 2012 * semaphore. 2013 */ 2014 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci) 2015 { 2016 spin_lock(&sci->sc_state_lock); 2017 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) { 2018 sci->sc_timer.expires = jiffies + sci->sc_interval; 2019 add_timer(&sci->sc_timer); 2020 sci->sc_state |= NILFS_SEGCTOR_COMMIT; 2021 } 2022 spin_unlock(&sci->sc_state_lock); 2023 } 2024 2025 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn) 2026 { 2027 spin_lock(&sci->sc_state_lock); 2028 if (!(sci->sc_flush_request & (1 << bn))) { 2029 unsigned long prev_req = sci->sc_flush_request; 2030 2031 sci->sc_flush_request |= (1 << bn); 2032 if (!prev_req) 2033 wake_up(&sci->sc_wait_daemon); 2034 } 2035 spin_unlock(&sci->sc_state_lock); 2036 } 2037 2038 /** 2039 * nilfs_flush_segment - trigger a segment construction for resource control 2040 * @sb: super block 2041 * @ino: inode number of the file to be flushed out. 2042 */ 2043 void nilfs_flush_segment(struct super_block *sb, ino_t ino) 2044 { 2045 struct the_nilfs *nilfs = sb->s_fs_info; 2046 struct nilfs_sc_info *sci = nilfs->ns_writer; 2047 2048 if (!sci || nilfs_doing_construction()) 2049 return; 2050 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0); 2051 /* assign bit 0 to data files */ 2052 } 2053 2054 struct nilfs_segctor_wait_request { 2055 wait_queue_t wq; 2056 __u32 seq; 2057 int err; 2058 atomic_t done; 2059 }; 2060 2061 static int nilfs_segctor_sync(struct nilfs_sc_info *sci) 2062 { 2063 struct nilfs_segctor_wait_request wait_req; 2064 int err = 0; 2065 2066 spin_lock(&sci->sc_state_lock); 2067 init_wait(&wait_req.wq); 2068 wait_req.err = 0; 2069 atomic_set(&wait_req.done, 0); 2070 wait_req.seq = ++sci->sc_seq_request; 2071 spin_unlock(&sci->sc_state_lock); 2072 2073 init_waitqueue_entry(&wait_req.wq, current); 2074 add_wait_queue(&sci->sc_wait_request, &wait_req.wq); 2075 set_current_state(TASK_INTERRUPTIBLE); 2076 wake_up(&sci->sc_wait_daemon); 2077 2078 for (;;) { 2079 if (atomic_read(&wait_req.done)) { 2080 err = wait_req.err; 2081 break; 2082 } 2083 if (!signal_pending(current)) { 2084 schedule(); 2085 continue; 2086 } 2087 err = -ERESTARTSYS; 2088 break; 2089 } 2090 finish_wait(&sci->sc_wait_request, &wait_req.wq); 2091 return err; 2092 } 2093 2094 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err) 2095 { 2096 struct nilfs_segctor_wait_request *wrq, *n; 2097 unsigned long flags; 2098 2099 spin_lock_irqsave(&sci->sc_wait_request.lock, flags); 2100 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list, 2101 wq.task_list) { 2102 if (!atomic_read(&wrq->done) && 2103 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) { 2104 wrq->err = err; 2105 atomic_set(&wrq->done, 1); 2106 } 2107 if (atomic_read(&wrq->done)) { 2108 wrq->wq.func(&wrq->wq, 2109 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 2110 0, NULL); 2111 } 2112 } 2113 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags); 2114 } 2115 2116 /** 2117 * nilfs_construct_segment - construct a logical segment 2118 * @sb: super block 2119 * 2120 * Return Value: On success, 0 is retured. On errors, one of the following 2121 * negative error code is returned. 2122 * 2123 * %-EROFS - Read only filesystem. 2124 * 2125 * %-EIO - I/O error 2126 * 2127 * %-ENOSPC - No space left on device (only in a panic state). 2128 * 2129 * %-ERESTARTSYS - Interrupted. 2130 * 2131 * %-ENOMEM - Insufficient memory available. 2132 */ 2133 int nilfs_construct_segment(struct super_block *sb) 2134 { 2135 struct the_nilfs *nilfs = sb->s_fs_info; 2136 struct nilfs_sc_info *sci = nilfs->ns_writer; 2137 struct nilfs_transaction_info *ti; 2138 int err; 2139 2140 if (!sci) 2141 return -EROFS; 2142 2143 /* A call inside transactions causes a deadlock. */ 2144 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC); 2145 2146 err = nilfs_segctor_sync(sci); 2147 return err; 2148 } 2149 2150 /** 2151 * nilfs_construct_dsync_segment - construct a data-only logical segment 2152 * @sb: super block 2153 * @inode: inode whose data blocks should be written out 2154 * @start: start byte offset 2155 * @end: end byte offset (inclusive) 2156 * 2157 * Return Value: On success, 0 is retured. On errors, one of the following 2158 * negative error code is returned. 2159 * 2160 * %-EROFS - Read only filesystem. 2161 * 2162 * %-EIO - I/O error 2163 * 2164 * %-ENOSPC - No space left on device (only in a panic state). 2165 * 2166 * %-ERESTARTSYS - Interrupted. 2167 * 2168 * %-ENOMEM - Insufficient memory available. 2169 */ 2170 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode, 2171 loff_t start, loff_t end) 2172 { 2173 struct the_nilfs *nilfs = sb->s_fs_info; 2174 struct nilfs_sc_info *sci = nilfs->ns_writer; 2175 struct nilfs_inode_info *ii; 2176 struct nilfs_transaction_info ti; 2177 int err = 0; 2178 2179 if (!sci) 2180 return -EROFS; 2181 2182 nilfs_transaction_lock(sb, &ti, 0); 2183 2184 ii = NILFS_I(inode); 2185 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) || 2186 nilfs_test_opt(nilfs, STRICT_ORDER) || 2187 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2188 nilfs_discontinued(nilfs)) { 2189 nilfs_transaction_unlock(sb); 2190 err = nilfs_segctor_sync(sci); 2191 return err; 2192 } 2193 2194 spin_lock(&nilfs->ns_inode_lock); 2195 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) && 2196 !test_bit(NILFS_I_BUSY, &ii->i_state)) { 2197 spin_unlock(&nilfs->ns_inode_lock); 2198 nilfs_transaction_unlock(sb); 2199 return 0; 2200 } 2201 spin_unlock(&nilfs->ns_inode_lock); 2202 sci->sc_dsync_inode = ii; 2203 sci->sc_dsync_start = start; 2204 sci->sc_dsync_end = end; 2205 2206 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC); 2207 2208 nilfs_transaction_unlock(sb); 2209 return err; 2210 } 2211 2212 #define FLUSH_FILE_BIT (0x1) /* data file only */ 2213 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */ 2214 2215 /** 2216 * nilfs_segctor_accept - record accepted sequence count of log-write requests 2217 * @sci: segment constructor object 2218 */ 2219 static void nilfs_segctor_accept(struct nilfs_sc_info *sci) 2220 { 2221 spin_lock(&sci->sc_state_lock); 2222 sci->sc_seq_accepted = sci->sc_seq_request; 2223 spin_unlock(&sci->sc_state_lock); 2224 del_timer_sync(&sci->sc_timer); 2225 } 2226 2227 /** 2228 * nilfs_segctor_notify - notify the result of request to caller threads 2229 * @sci: segment constructor object 2230 * @mode: mode of log forming 2231 * @err: error code to be notified 2232 */ 2233 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err) 2234 { 2235 /* Clear requests (even when the construction failed) */ 2236 spin_lock(&sci->sc_state_lock); 2237 2238 if (mode == SC_LSEG_SR) { 2239 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT; 2240 sci->sc_seq_done = sci->sc_seq_accepted; 2241 nilfs_segctor_wakeup(sci, err); 2242 sci->sc_flush_request = 0; 2243 } else { 2244 if (mode == SC_FLUSH_FILE) 2245 sci->sc_flush_request &= ~FLUSH_FILE_BIT; 2246 else if (mode == SC_FLUSH_DAT) 2247 sci->sc_flush_request &= ~FLUSH_DAT_BIT; 2248 2249 /* re-enable timer if checkpoint creation was not done */ 2250 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2251 time_before(jiffies, sci->sc_timer.expires)) 2252 add_timer(&sci->sc_timer); 2253 } 2254 spin_unlock(&sci->sc_state_lock); 2255 } 2256 2257 /** 2258 * nilfs_segctor_construct - form logs and write them to disk 2259 * @sci: segment constructor object 2260 * @mode: mode of log forming 2261 */ 2262 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode) 2263 { 2264 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2265 struct nilfs_super_block **sbp; 2266 int err = 0; 2267 2268 nilfs_segctor_accept(sci); 2269 2270 if (nilfs_discontinued(nilfs)) 2271 mode = SC_LSEG_SR; 2272 if (!nilfs_segctor_confirm(sci)) 2273 err = nilfs_segctor_do_construct(sci, mode); 2274 2275 if (likely(!err)) { 2276 if (mode != SC_FLUSH_DAT) 2277 atomic_set(&nilfs->ns_ndirtyblks, 0); 2278 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) && 2279 nilfs_discontinued(nilfs)) { 2280 down_write(&nilfs->ns_sem); 2281 err = -EIO; 2282 sbp = nilfs_prepare_super(sci->sc_super, 2283 nilfs_sb_will_flip(nilfs)); 2284 if (likely(sbp)) { 2285 nilfs_set_log_cursor(sbp[0], nilfs); 2286 err = nilfs_commit_super(sci->sc_super, 2287 NILFS_SB_COMMIT); 2288 } 2289 up_write(&nilfs->ns_sem); 2290 } 2291 } 2292 2293 nilfs_segctor_notify(sci, mode, err); 2294 return err; 2295 } 2296 2297 static void nilfs_construction_timeout(unsigned long data) 2298 { 2299 struct task_struct *p = (struct task_struct *)data; 2300 wake_up_process(p); 2301 } 2302 2303 static void 2304 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head) 2305 { 2306 struct nilfs_inode_info *ii, *n; 2307 2308 list_for_each_entry_safe(ii, n, head, i_dirty) { 2309 if (!test_bit(NILFS_I_UPDATED, &ii->i_state)) 2310 continue; 2311 list_del_init(&ii->i_dirty); 2312 iput(&ii->vfs_inode); 2313 } 2314 } 2315 2316 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv, 2317 void **kbufs) 2318 { 2319 struct the_nilfs *nilfs = sb->s_fs_info; 2320 struct nilfs_sc_info *sci = nilfs->ns_writer; 2321 struct nilfs_transaction_info ti; 2322 int err; 2323 2324 if (unlikely(!sci)) 2325 return -EROFS; 2326 2327 nilfs_transaction_lock(sb, &ti, 1); 2328 2329 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat); 2330 if (unlikely(err)) 2331 goto out_unlock; 2332 2333 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs); 2334 if (unlikely(err)) { 2335 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat); 2336 goto out_unlock; 2337 } 2338 2339 sci->sc_freesegs = kbufs[4]; 2340 sci->sc_nfreesegs = argv[4].v_nmembs; 2341 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes); 2342 2343 for (;;) { 2344 err = nilfs_segctor_construct(sci, SC_LSEG_SR); 2345 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes); 2346 2347 if (likely(!err)) 2348 break; 2349 2350 nilfs_warning(sb, __func__, 2351 "segment construction failed. (err=%d)", err); 2352 set_current_state(TASK_INTERRUPTIBLE); 2353 schedule_timeout(sci->sc_interval); 2354 } 2355 if (nilfs_test_opt(nilfs, DISCARD)) { 2356 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs, 2357 sci->sc_nfreesegs); 2358 if (ret) { 2359 printk(KERN_WARNING 2360 "NILFS warning: error %d on discard request, " 2361 "turning discards off for the device\n", ret); 2362 nilfs_clear_opt(nilfs, DISCARD); 2363 } 2364 } 2365 2366 out_unlock: 2367 sci->sc_freesegs = NULL; 2368 sci->sc_nfreesegs = 0; 2369 nilfs_mdt_clear_shadow_map(nilfs->ns_dat); 2370 nilfs_transaction_unlock(sb); 2371 return err; 2372 } 2373 2374 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode) 2375 { 2376 struct nilfs_transaction_info ti; 2377 2378 nilfs_transaction_lock(sci->sc_super, &ti, 0); 2379 nilfs_segctor_construct(sci, mode); 2380 2381 /* 2382 * Unclosed segment should be retried. We do this using sc_timer. 2383 * Timeout of sc_timer will invoke complete construction which leads 2384 * to close the current logical segment. 2385 */ 2386 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) 2387 nilfs_segctor_start_timer(sci); 2388 2389 nilfs_transaction_unlock(sci->sc_super); 2390 } 2391 2392 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci) 2393 { 2394 int mode = 0; 2395 int err; 2396 2397 spin_lock(&sci->sc_state_lock); 2398 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ? 2399 SC_FLUSH_DAT : SC_FLUSH_FILE; 2400 spin_unlock(&sci->sc_state_lock); 2401 2402 if (mode) { 2403 err = nilfs_segctor_do_construct(sci, mode); 2404 2405 spin_lock(&sci->sc_state_lock); 2406 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ? 2407 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT; 2408 spin_unlock(&sci->sc_state_lock); 2409 } 2410 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 2411 } 2412 2413 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci) 2414 { 2415 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2416 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) { 2417 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT)) 2418 return SC_FLUSH_FILE; 2419 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT)) 2420 return SC_FLUSH_DAT; 2421 } 2422 return SC_LSEG_SR; 2423 } 2424 2425 /** 2426 * nilfs_segctor_thread - main loop of the segment constructor thread. 2427 * @arg: pointer to a struct nilfs_sc_info. 2428 * 2429 * nilfs_segctor_thread() initializes a timer and serves as a daemon 2430 * to execute segment constructions. 2431 */ 2432 static int nilfs_segctor_thread(void *arg) 2433 { 2434 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg; 2435 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2436 int timeout = 0; 2437 2438 sci->sc_timer.data = (unsigned long)current; 2439 sci->sc_timer.function = nilfs_construction_timeout; 2440 2441 /* start sync. */ 2442 sci->sc_task = current; 2443 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */ 2444 printk(KERN_INFO 2445 "segctord starting. Construction interval = %lu seconds, " 2446 "CP frequency < %lu seconds\n", 2447 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ); 2448 2449 spin_lock(&sci->sc_state_lock); 2450 loop: 2451 for (;;) { 2452 int mode; 2453 2454 if (sci->sc_state & NILFS_SEGCTOR_QUIT) 2455 goto end_thread; 2456 2457 if (timeout || sci->sc_seq_request != sci->sc_seq_done) 2458 mode = SC_LSEG_SR; 2459 else if (!sci->sc_flush_request) 2460 break; 2461 else 2462 mode = nilfs_segctor_flush_mode(sci); 2463 2464 spin_unlock(&sci->sc_state_lock); 2465 nilfs_segctor_thread_construct(sci, mode); 2466 spin_lock(&sci->sc_state_lock); 2467 timeout = 0; 2468 } 2469 2470 2471 if (freezing(current)) { 2472 spin_unlock(&sci->sc_state_lock); 2473 try_to_freeze(); 2474 spin_lock(&sci->sc_state_lock); 2475 } else { 2476 DEFINE_WAIT(wait); 2477 int should_sleep = 1; 2478 2479 prepare_to_wait(&sci->sc_wait_daemon, &wait, 2480 TASK_INTERRUPTIBLE); 2481 2482 if (sci->sc_seq_request != sci->sc_seq_done) 2483 should_sleep = 0; 2484 else if (sci->sc_flush_request) 2485 should_sleep = 0; 2486 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT) 2487 should_sleep = time_before(jiffies, 2488 sci->sc_timer.expires); 2489 2490 if (should_sleep) { 2491 spin_unlock(&sci->sc_state_lock); 2492 schedule(); 2493 spin_lock(&sci->sc_state_lock); 2494 } 2495 finish_wait(&sci->sc_wait_daemon, &wait); 2496 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2497 time_after_eq(jiffies, sci->sc_timer.expires)); 2498 2499 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs)) 2500 set_nilfs_discontinued(nilfs); 2501 } 2502 goto loop; 2503 2504 end_thread: 2505 spin_unlock(&sci->sc_state_lock); 2506 2507 /* end sync. */ 2508 sci->sc_task = NULL; 2509 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */ 2510 return 0; 2511 } 2512 2513 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci) 2514 { 2515 struct task_struct *t; 2516 2517 t = kthread_run(nilfs_segctor_thread, sci, "segctord"); 2518 if (IS_ERR(t)) { 2519 int err = PTR_ERR(t); 2520 2521 printk(KERN_ERR "NILFS: error %d creating segctord thread\n", 2522 err); 2523 return err; 2524 } 2525 wait_event(sci->sc_wait_task, sci->sc_task != NULL); 2526 return 0; 2527 } 2528 2529 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci) 2530 __acquires(&sci->sc_state_lock) 2531 __releases(&sci->sc_state_lock) 2532 { 2533 sci->sc_state |= NILFS_SEGCTOR_QUIT; 2534 2535 while (sci->sc_task) { 2536 wake_up(&sci->sc_wait_daemon); 2537 spin_unlock(&sci->sc_state_lock); 2538 wait_event(sci->sc_wait_task, sci->sc_task == NULL); 2539 spin_lock(&sci->sc_state_lock); 2540 } 2541 } 2542 2543 /* 2544 * Setup & clean-up functions 2545 */ 2546 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb, 2547 struct nilfs_root *root) 2548 { 2549 struct the_nilfs *nilfs = sb->s_fs_info; 2550 struct nilfs_sc_info *sci; 2551 2552 sci = kzalloc(sizeof(*sci), GFP_KERNEL); 2553 if (!sci) 2554 return NULL; 2555 2556 sci->sc_super = sb; 2557 2558 nilfs_get_root(root); 2559 sci->sc_root = root; 2560 2561 init_waitqueue_head(&sci->sc_wait_request); 2562 init_waitqueue_head(&sci->sc_wait_daemon); 2563 init_waitqueue_head(&sci->sc_wait_task); 2564 spin_lock_init(&sci->sc_state_lock); 2565 INIT_LIST_HEAD(&sci->sc_dirty_files); 2566 INIT_LIST_HEAD(&sci->sc_segbufs); 2567 INIT_LIST_HEAD(&sci->sc_write_logs); 2568 INIT_LIST_HEAD(&sci->sc_gc_inodes); 2569 init_timer(&sci->sc_timer); 2570 2571 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT; 2572 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ; 2573 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK; 2574 2575 if (nilfs->ns_interval) 2576 sci->sc_interval = HZ * nilfs->ns_interval; 2577 if (nilfs->ns_watermark) 2578 sci->sc_watermark = nilfs->ns_watermark; 2579 return sci; 2580 } 2581 2582 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci) 2583 { 2584 int ret, retrycount = NILFS_SC_CLEANUP_RETRY; 2585 2586 /* The segctord thread was stopped and its timer was removed. 2587 But some tasks remain. */ 2588 do { 2589 struct nilfs_transaction_info ti; 2590 2591 nilfs_transaction_lock(sci->sc_super, &ti, 0); 2592 ret = nilfs_segctor_construct(sci, SC_LSEG_SR); 2593 nilfs_transaction_unlock(sci->sc_super); 2594 2595 } while (ret && retrycount-- > 0); 2596 } 2597 2598 /** 2599 * nilfs_segctor_destroy - destroy the segment constructor. 2600 * @sci: nilfs_sc_info 2601 * 2602 * nilfs_segctor_destroy() kills the segctord thread and frees 2603 * the nilfs_sc_info struct. 2604 * Caller must hold the segment semaphore. 2605 */ 2606 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci) 2607 { 2608 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2609 int flag; 2610 2611 up_write(&nilfs->ns_segctor_sem); 2612 2613 spin_lock(&sci->sc_state_lock); 2614 nilfs_segctor_kill_thread(sci); 2615 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request 2616 || sci->sc_seq_request != sci->sc_seq_done); 2617 spin_unlock(&sci->sc_state_lock); 2618 2619 if (flag || !nilfs_segctor_confirm(sci)) 2620 nilfs_segctor_write_out(sci); 2621 2622 if (!list_empty(&sci->sc_dirty_files)) { 2623 nilfs_warning(sci->sc_super, __func__, 2624 "dirty file(s) after the final construction\n"); 2625 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1); 2626 } 2627 2628 WARN_ON(!list_empty(&sci->sc_segbufs)); 2629 WARN_ON(!list_empty(&sci->sc_write_logs)); 2630 2631 nilfs_put_root(sci->sc_root); 2632 2633 down_write(&nilfs->ns_segctor_sem); 2634 2635 del_timer_sync(&sci->sc_timer); 2636 kfree(sci); 2637 } 2638 2639 /** 2640 * nilfs_attach_log_writer - attach log writer 2641 * @sb: super block instance 2642 * @root: root object of the current filesystem tree 2643 * 2644 * This allocates a log writer object, initializes it, and starts the 2645 * log writer. 2646 * 2647 * Return Value: On success, 0 is returned. On error, one of the following 2648 * negative error code is returned. 2649 * 2650 * %-ENOMEM - Insufficient memory available. 2651 */ 2652 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root) 2653 { 2654 struct the_nilfs *nilfs = sb->s_fs_info; 2655 int err; 2656 2657 if (nilfs->ns_writer) { 2658 /* 2659 * This happens if the filesystem was remounted 2660 * read/write after nilfs_error degenerated it into a 2661 * read-only mount. 2662 */ 2663 nilfs_detach_log_writer(sb); 2664 } 2665 2666 nilfs->ns_writer = nilfs_segctor_new(sb, root); 2667 if (!nilfs->ns_writer) 2668 return -ENOMEM; 2669 2670 err = nilfs_segctor_start_thread(nilfs->ns_writer); 2671 if (err) { 2672 kfree(nilfs->ns_writer); 2673 nilfs->ns_writer = NULL; 2674 } 2675 return err; 2676 } 2677 2678 /** 2679 * nilfs_detach_log_writer - destroy log writer 2680 * @sb: super block instance 2681 * 2682 * This kills log writer daemon, frees the log writer object, and 2683 * destroys list of dirty files. 2684 */ 2685 void nilfs_detach_log_writer(struct super_block *sb) 2686 { 2687 struct the_nilfs *nilfs = sb->s_fs_info; 2688 LIST_HEAD(garbage_list); 2689 2690 down_write(&nilfs->ns_segctor_sem); 2691 if (nilfs->ns_writer) { 2692 nilfs_segctor_destroy(nilfs->ns_writer); 2693 nilfs->ns_writer = NULL; 2694 } 2695 2696 /* Force to free the list of dirty files */ 2697 spin_lock(&nilfs->ns_inode_lock); 2698 if (!list_empty(&nilfs->ns_dirty_files)) { 2699 list_splice_init(&nilfs->ns_dirty_files, &garbage_list); 2700 nilfs_warning(sb, __func__, 2701 "Hit dirty file after stopped log writer\n"); 2702 } 2703 spin_unlock(&nilfs->ns_inode_lock); 2704 up_write(&nilfs->ns_segctor_sem); 2705 2706 nilfs_dispose_list(nilfs, &garbage_list, 1); 2707 } 2708