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/bitops.h> 28 #include <linux/bio.h> 29 #include <linux/completion.h> 30 #include <linux/blkdev.h> 31 #include <linux/backing-dev.h> 32 #include <linux/freezer.h> 33 #include <linux/kthread.h> 34 #include <linux/crc32.h> 35 #include <linux/pagevec.h> 36 #include <linux/slab.h> 37 #include "nilfs.h" 38 #include "btnode.h" 39 #include "page.h" 40 #include "segment.h" 41 #include "sufile.h" 42 #include "cpfile.h" 43 #include "ifile.h" 44 #include "segbuf.h" 45 46 47 /* 48 * Segment constructor 49 */ 50 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */ 51 52 #define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments 53 appended in collection retry loop */ 54 55 /* Construction mode */ 56 enum { 57 SC_LSEG_SR = 1, /* Make a logical segment having a super root */ 58 SC_LSEG_DSYNC, /* Flush data blocks of a given file and make 59 a logical segment without a super root */ 60 SC_FLUSH_FILE, /* Flush data files, leads to segment writes without 61 creating a checkpoint */ 62 SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without 63 a checkpoint */ 64 }; 65 66 /* Stage numbers of dirty block collection */ 67 enum { 68 NILFS_ST_INIT = 0, 69 NILFS_ST_GC, /* Collecting dirty blocks for GC */ 70 NILFS_ST_FILE, 71 NILFS_ST_IFILE, 72 NILFS_ST_CPFILE, 73 NILFS_ST_SUFILE, 74 NILFS_ST_DAT, 75 NILFS_ST_SR, /* Super root */ 76 NILFS_ST_DSYNC, /* Data sync blocks */ 77 NILFS_ST_DONE, 78 }; 79 80 /* State flags of collection */ 81 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */ 82 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */ 83 #define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */ 84 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED) 85 86 /* Operations depending on the construction mode and file type */ 87 struct nilfs_sc_operations { 88 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *, 89 struct inode *); 90 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *, 91 struct inode *); 92 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *, 93 struct inode *); 94 void (*write_data_binfo)(struct nilfs_sc_info *, 95 struct nilfs_segsum_pointer *, 96 union nilfs_binfo *); 97 void (*write_node_binfo)(struct nilfs_sc_info *, 98 struct nilfs_segsum_pointer *, 99 union nilfs_binfo *); 100 }; 101 102 /* 103 * Other definitions 104 */ 105 static void nilfs_segctor_start_timer(struct nilfs_sc_info *); 106 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int); 107 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *); 108 static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, 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 the_nilfs *nilfs; 186 int ret = nilfs_prepare_segment_lock(ti); 187 188 if (unlikely(ret < 0)) 189 return ret; 190 if (ret > 0) 191 return 0; 192 193 sb_start_intwrite(sb); 194 195 nilfs = sb->s_fs_info; 196 down_read(&nilfs->ns_segctor_sem); 197 if (vacancy_check && nilfs_near_disk_full(nilfs)) { 198 up_read(&nilfs->ns_segctor_sem); 199 ret = -ENOSPC; 200 goto failed; 201 } 202 return 0; 203 204 failed: 205 ti = current->journal_info; 206 current->journal_info = ti->ti_save; 207 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 208 kmem_cache_free(nilfs_transaction_cachep, ti); 209 sb_end_intwrite(sb); 210 return ret; 211 } 212 213 /** 214 * nilfs_transaction_commit - commit indivisible file operations. 215 * @sb: super block 216 * 217 * nilfs_transaction_commit() releases the read semaphore which is 218 * acquired by nilfs_transaction_begin(). This is only performed 219 * in outermost call of this function. If a commit flag is set, 220 * nilfs_transaction_commit() sets a timer to start the segment 221 * constructor. If a sync flag is set, it starts construction 222 * directly. 223 */ 224 int nilfs_transaction_commit(struct super_block *sb) 225 { 226 struct nilfs_transaction_info *ti = current->journal_info; 227 struct the_nilfs *nilfs = sb->s_fs_info; 228 int err = 0; 229 230 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 231 ti->ti_flags |= NILFS_TI_COMMIT; 232 if (ti->ti_count > 0) { 233 ti->ti_count--; 234 return 0; 235 } 236 if (nilfs->ns_writer) { 237 struct nilfs_sc_info *sci = nilfs->ns_writer; 238 239 if (ti->ti_flags & NILFS_TI_COMMIT) 240 nilfs_segctor_start_timer(sci); 241 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark) 242 nilfs_segctor_do_flush(sci, 0); 243 } 244 up_read(&nilfs->ns_segctor_sem); 245 current->journal_info = ti->ti_save; 246 247 if (ti->ti_flags & NILFS_TI_SYNC) 248 err = nilfs_construct_segment(sb); 249 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 250 kmem_cache_free(nilfs_transaction_cachep, ti); 251 sb_end_intwrite(sb); 252 return err; 253 } 254 255 void nilfs_transaction_abort(struct super_block *sb) 256 { 257 struct nilfs_transaction_info *ti = current->journal_info; 258 struct the_nilfs *nilfs = sb->s_fs_info; 259 260 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 261 if (ti->ti_count > 0) { 262 ti->ti_count--; 263 return; 264 } 265 up_read(&nilfs->ns_segctor_sem); 266 267 current->journal_info = ti->ti_save; 268 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 269 kmem_cache_free(nilfs_transaction_cachep, ti); 270 sb_end_intwrite(sb); 271 } 272 273 void nilfs_relax_pressure_in_lock(struct super_block *sb) 274 { 275 struct the_nilfs *nilfs = sb->s_fs_info; 276 struct nilfs_sc_info *sci = nilfs->ns_writer; 277 278 if (!sci || !sci->sc_flush_request) 279 return; 280 281 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 282 up_read(&nilfs->ns_segctor_sem); 283 284 down_write(&nilfs->ns_segctor_sem); 285 if (sci->sc_flush_request && 286 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) { 287 struct nilfs_transaction_info *ti = current->journal_info; 288 289 ti->ti_flags |= NILFS_TI_WRITER; 290 nilfs_segctor_do_immediate_flush(sci); 291 ti->ti_flags &= ~NILFS_TI_WRITER; 292 } 293 downgrade_write(&nilfs->ns_segctor_sem); 294 } 295 296 static void nilfs_transaction_lock(struct super_block *sb, 297 struct nilfs_transaction_info *ti, 298 int gcflag) 299 { 300 struct nilfs_transaction_info *cur_ti = current->journal_info; 301 struct the_nilfs *nilfs = sb->s_fs_info; 302 struct nilfs_sc_info *sci = nilfs->ns_writer; 303 304 WARN_ON(cur_ti); 305 ti->ti_flags = NILFS_TI_WRITER; 306 ti->ti_count = 0; 307 ti->ti_save = cur_ti; 308 ti->ti_magic = NILFS_TI_MAGIC; 309 current->journal_info = ti; 310 311 for (;;) { 312 down_write(&nilfs->ns_segctor_sem); 313 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) 314 break; 315 316 nilfs_segctor_do_immediate_flush(sci); 317 318 up_write(&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 super_block *sb) 326 { 327 struct nilfs_transaction_info *ti = current->journal_info; 328 struct the_nilfs *nilfs = sb->s_fs_info; 329 330 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 331 BUG_ON(ti->ti_count > 0); 332 333 up_write(&nilfs->ns_segctor_sem); 334 current->journal_info = ti->ti_save; 335 } 336 337 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci, 338 struct nilfs_segsum_pointer *ssp, 339 unsigned bytes) 340 { 341 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 342 unsigned blocksize = sci->sc_super->s_blocksize; 343 void *p; 344 345 if (unlikely(ssp->offset + bytes > blocksize)) { 346 ssp->offset = 0; 347 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh, 348 &segbuf->sb_segsum_buffers)); 349 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh); 350 } 351 p = ssp->bh->b_data + ssp->offset; 352 ssp->offset += bytes; 353 return p; 354 } 355 356 /** 357 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer 358 * @sci: nilfs_sc_info 359 */ 360 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci) 361 { 362 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 363 struct buffer_head *sumbh; 364 unsigned sumbytes; 365 unsigned flags = 0; 366 int err; 367 368 if (nilfs_doing_gc()) 369 flags = NILFS_SS_GC; 370 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno); 371 if (unlikely(err)) 372 return err; 373 374 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); 375 sumbytes = segbuf->sb_sum.sumbytes; 376 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes; 377 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes; 378 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; 379 return 0; 380 } 381 382 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci) 383 { 384 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; 385 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs)) 386 return -E2BIG; /* The current segment is filled up 387 (internal code) */ 388 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg); 389 return nilfs_segctor_reset_segment_buffer(sci); 390 } 391 392 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci) 393 { 394 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 395 int err; 396 397 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) { 398 err = nilfs_segctor_feed_segment(sci); 399 if (err) 400 return err; 401 segbuf = sci->sc_curseg; 402 } 403 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root); 404 if (likely(!err)) 405 segbuf->sb_sum.flags |= NILFS_SS_SR; 406 return err; 407 } 408 409 /* 410 * Functions for making segment summary and payloads 411 */ 412 static int nilfs_segctor_segsum_block_required( 413 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp, 414 unsigned binfo_size) 415 { 416 unsigned blocksize = sci->sc_super->s_blocksize; 417 /* Size of finfo and binfo is enough small against blocksize */ 418 419 return ssp->offset + binfo_size + 420 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) > 421 blocksize; 422 } 423 424 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci, 425 struct inode *inode) 426 { 427 sci->sc_curseg->sb_sum.nfinfo++; 428 sci->sc_binfo_ptr = sci->sc_finfo_ptr; 429 nilfs_segctor_map_segsum_entry( 430 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo)); 431 432 if (NILFS_I(inode)->i_root && 433 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 434 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 435 /* skip finfo */ 436 } 437 438 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci, 439 struct inode *inode) 440 { 441 struct nilfs_finfo *finfo; 442 struct nilfs_inode_info *ii; 443 struct nilfs_segment_buffer *segbuf; 444 __u64 cno; 445 446 if (sci->sc_blk_cnt == 0) 447 return; 448 449 ii = NILFS_I(inode); 450 451 if (test_bit(NILFS_I_GCINODE, &ii->i_state)) 452 cno = ii->i_cno; 453 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) 454 cno = 0; 455 else 456 cno = sci->sc_cno; 457 458 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr, 459 sizeof(*finfo)); 460 finfo->fi_ino = cpu_to_le64(inode->i_ino); 461 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt); 462 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt); 463 finfo->fi_cno = cpu_to_le64(cno); 464 465 segbuf = sci->sc_curseg; 466 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset + 467 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1); 468 sci->sc_finfo_ptr = sci->sc_binfo_ptr; 469 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; 470 } 471 472 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci, 473 struct buffer_head *bh, 474 struct inode *inode, 475 unsigned binfo_size) 476 { 477 struct nilfs_segment_buffer *segbuf; 478 int required, err = 0; 479 480 retry: 481 segbuf = sci->sc_curseg; 482 required = nilfs_segctor_segsum_block_required( 483 sci, &sci->sc_binfo_ptr, binfo_size); 484 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) { 485 nilfs_segctor_end_finfo(sci, inode); 486 err = nilfs_segctor_feed_segment(sci); 487 if (err) 488 return err; 489 goto retry; 490 } 491 if (unlikely(required)) { 492 err = nilfs_segbuf_extend_segsum(segbuf); 493 if (unlikely(err)) 494 goto failed; 495 } 496 if (sci->sc_blk_cnt == 0) 497 nilfs_segctor_begin_finfo(sci, inode); 498 499 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size); 500 /* Substitution to vblocknr is delayed until update_blocknr() */ 501 nilfs_segbuf_add_file_buffer(segbuf, bh); 502 sci->sc_blk_cnt++; 503 failed: 504 return err; 505 } 506 507 /* 508 * Callback functions that enumerate, mark, and collect dirty blocks 509 */ 510 static int nilfs_collect_file_data(struct nilfs_sc_info *sci, 511 struct buffer_head *bh, struct inode *inode) 512 { 513 int err; 514 515 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 516 if (err < 0) 517 return err; 518 519 err = nilfs_segctor_add_file_block(sci, bh, inode, 520 sizeof(struct nilfs_binfo_v)); 521 if (!err) 522 sci->sc_datablk_cnt++; 523 return err; 524 } 525 526 static int nilfs_collect_file_node(struct nilfs_sc_info *sci, 527 struct buffer_head *bh, 528 struct inode *inode) 529 { 530 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 531 } 532 533 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci, 534 struct buffer_head *bh, 535 struct inode *inode) 536 { 537 WARN_ON(!buffer_dirty(bh)); 538 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); 539 } 540 541 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci, 542 struct nilfs_segsum_pointer *ssp, 543 union nilfs_binfo *binfo) 544 { 545 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry( 546 sci, ssp, sizeof(*binfo_v)); 547 *binfo_v = binfo->bi_v; 548 } 549 550 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci, 551 struct nilfs_segsum_pointer *ssp, 552 union nilfs_binfo *binfo) 553 { 554 __le64 *vblocknr = nilfs_segctor_map_segsum_entry( 555 sci, ssp, sizeof(*vblocknr)); 556 *vblocknr = binfo->bi_v.bi_vblocknr; 557 } 558 559 static struct nilfs_sc_operations nilfs_sc_file_ops = { 560 .collect_data = nilfs_collect_file_data, 561 .collect_node = nilfs_collect_file_node, 562 .collect_bmap = nilfs_collect_file_bmap, 563 .write_data_binfo = nilfs_write_file_data_binfo, 564 .write_node_binfo = nilfs_write_file_node_binfo, 565 }; 566 567 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci, 568 struct buffer_head *bh, struct inode *inode) 569 { 570 int err; 571 572 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 573 if (err < 0) 574 return err; 575 576 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); 577 if (!err) 578 sci->sc_datablk_cnt++; 579 return err; 580 } 581 582 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci, 583 struct buffer_head *bh, struct inode *inode) 584 { 585 WARN_ON(!buffer_dirty(bh)); 586 return nilfs_segctor_add_file_block(sci, bh, inode, 587 sizeof(struct nilfs_binfo_dat)); 588 } 589 590 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci, 591 struct nilfs_segsum_pointer *ssp, 592 union nilfs_binfo *binfo) 593 { 594 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp, 595 sizeof(*blkoff)); 596 *blkoff = binfo->bi_dat.bi_blkoff; 597 } 598 599 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci, 600 struct nilfs_segsum_pointer *ssp, 601 union nilfs_binfo *binfo) 602 { 603 struct nilfs_binfo_dat *binfo_dat = 604 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat)); 605 *binfo_dat = binfo->bi_dat; 606 } 607 608 static struct nilfs_sc_operations nilfs_sc_dat_ops = { 609 .collect_data = nilfs_collect_dat_data, 610 .collect_node = nilfs_collect_file_node, 611 .collect_bmap = nilfs_collect_dat_bmap, 612 .write_data_binfo = nilfs_write_dat_data_binfo, 613 .write_node_binfo = nilfs_write_dat_node_binfo, 614 }; 615 616 static struct nilfs_sc_operations nilfs_sc_dsync_ops = { 617 .collect_data = nilfs_collect_file_data, 618 .collect_node = NULL, 619 .collect_bmap = NULL, 620 .write_data_binfo = nilfs_write_file_data_binfo, 621 .write_node_binfo = NULL, 622 }; 623 624 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode, 625 struct list_head *listp, 626 size_t nlimit, 627 loff_t start, loff_t end) 628 { 629 struct address_space *mapping = inode->i_mapping; 630 struct pagevec pvec; 631 pgoff_t index = 0, last = ULONG_MAX; 632 size_t ndirties = 0; 633 int i; 634 635 if (unlikely(start != 0 || end != LLONG_MAX)) { 636 /* 637 * A valid range is given for sync-ing data pages. The 638 * range is rounded to per-page; extra dirty buffers 639 * may be included if blocksize < pagesize. 640 */ 641 index = start >> PAGE_SHIFT; 642 last = end >> PAGE_SHIFT; 643 } 644 pagevec_init(&pvec, 0); 645 repeat: 646 if (unlikely(index > last) || 647 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 648 min_t(pgoff_t, last - index, 649 PAGEVEC_SIZE - 1) + 1)) 650 return ndirties; 651 652 for (i = 0; i < pagevec_count(&pvec); i++) { 653 struct buffer_head *bh, *head; 654 struct page *page = pvec.pages[i]; 655 656 if (unlikely(page->index > last)) 657 break; 658 659 lock_page(page); 660 if (!page_has_buffers(page)) 661 create_empty_buffers(page, 1 << inode->i_blkbits, 0); 662 unlock_page(page); 663 664 bh = head = page_buffers(page); 665 do { 666 if (!buffer_dirty(bh) || buffer_async_write(bh)) 667 continue; 668 get_bh(bh); 669 list_add_tail(&bh->b_assoc_buffers, listp); 670 ndirties++; 671 if (unlikely(ndirties >= nlimit)) { 672 pagevec_release(&pvec); 673 cond_resched(); 674 return ndirties; 675 } 676 } while (bh = bh->b_this_page, bh != head); 677 } 678 pagevec_release(&pvec); 679 cond_resched(); 680 goto repeat; 681 } 682 683 static void nilfs_lookup_dirty_node_buffers(struct inode *inode, 684 struct list_head *listp) 685 { 686 struct nilfs_inode_info *ii = NILFS_I(inode); 687 struct address_space *mapping = &ii->i_btnode_cache; 688 struct pagevec pvec; 689 struct buffer_head *bh, *head; 690 unsigned int i; 691 pgoff_t index = 0; 692 693 pagevec_init(&pvec, 0); 694 695 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 696 PAGEVEC_SIZE)) { 697 for (i = 0; i < pagevec_count(&pvec); i++) { 698 bh = head = page_buffers(pvec.pages[i]); 699 do { 700 if (buffer_dirty(bh) && 701 !buffer_async_write(bh)) { 702 get_bh(bh); 703 list_add_tail(&bh->b_assoc_buffers, 704 listp); 705 } 706 bh = bh->b_this_page; 707 } while (bh != head); 708 } 709 pagevec_release(&pvec); 710 cond_resched(); 711 } 712 } 713 714 static void nilfs_dispose_list(struct the_nilfs *nilfs, 715 struct list_head *head, int force) 716 { 717 struct nilfs_inode_info *ii, *n; 718 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii; 719 unsigned nv = 0; 720 721 while (!list_empty(head)) { 722 spin_lock(&nilfs->ns_inode_lock); 723 list_for_each_entry_safe(ii, n, head, i_dirty) { 724 list_del_init(&ii->i_dirty); 725 if (force) { 726 if (unlikely(ii->i_bh)) { 727 brelse(ii->i_bh); 728 ii->i_bh = NULL; 729 } 730 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) { 731 set_bit(NILFS_I_QUEUED, &ii->i_state); 732 list_add_tail(&ii->i_dirty, 733 &nilfs->ns_dirty_files); 734 continue; 735 } 736 ivec[nv++] = ii; 737 if (nv == SC_N_INODEVEC) 738 break; 739 } 740 spin_unlock(&nilfs->ns_inode_lock); 741 742 for (pii = ivec; nv > 0; pii++, nv--) 743 iput(&(*pii)->vfs_inode); 744 } 745 } 746 747 static void nilfs_iput_work_func(struct work_struct *work) 748 { 749 struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info, 750 sc_iput_work); 751 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 752 753 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0); 754 } 755 756 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs, 757 struct nilfs_root *root) 758 { 759 int ret = 0; 760 761 if (nilfs_mdt_fetch_dirty(root->ifile)) 762 ret++; 763 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile)) 764 ret++; 765 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile)) 766 ret++; 767 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat)) 768 ret++; 769 return ret; 770 } 771 772 static int nilfs_segctor_clean(struct nilfs_sc_info *sci) 773 { 774 return list_empty(&sci->sc_dirty_files) && 775 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) && 776 sci->sc_nfreesegs == 0 && 777 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes)); 778 } 779 780 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci) 781 { 782 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 783 int ret = 0; 784 785 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 786 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 787 788 spin_lock(&nilfs->ns_inode_lock); 789 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci)) 790 ret++; 791 792 spin_unlock(&nilfs->ns_inode_lock); 793 return ret; 794 } 795 796 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci) 797 { 798 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 799 800 nilfs_mdt_clear_dirty(sci->sc_root->ifile); 801 nilfs_mdt_clear_dirty(nilfs->ns_cpfile); 802 nilfs_mdt_clear_dirty(nilfs->ns_sufile); 803 nilfs_mdt_clear_dirty(nilfs->ns_dat); 804 } 805 806 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci) 807 { 808 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 809 struct buffer_head *bh_cp; 810 struct nilfs_checkpoint *raw_cp; 811 int err; 812 813 /* XXX: this interface will be changed */ 814 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1, 815 &raw_cp, &bh_cp); 816 if (likely(!err)) { 817 /* The following code is duplicated with cpfile. But, it is 818 needed to collect the checkpoint even if it was not newly 819 created */ 820 mark_buffer_dirty(bh_cp); 821 nilfs_mdt_mark_dirty(nilfs->ns_cpfile); 822 nilfs_cpfile_put_checkpoint( 823 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 824 } else 825 WARN_ON(err == -EINVAL || err == -ENOENT); 826 827 return err; 828 } 829 830 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci) 831 { 832 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 833 struct buffer_head *bh_cp; 834 struct nilfs_checkpoint *raw_cp; 835 int err; 836 837 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0, 838 &raw_cp, &bh_cp); 839 if (unlikely(err)) { 840 WARN_ON(err == -EINVAL || err == -ENOENT); 841 goto failed_ibh; 842 } 843 raw_cp->cp_snapshot_list.ssl_next = 0; 844 raw_cp->cp_snapshot_list.ssl_prev = 0; 845 raw_cp->cp_inodes_count = 846 cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count)); 847 raw_cp->cp_blocks_count = 848 cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count)); 849 raw_cp->cp_nblk_inc = 850 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc); 851 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime); 852 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno); 853 854 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 855 nilfs_checkpoint_clear_minor(raw_cp); 856 else 857 nilfs_checkpoint_set_minor(raw_cp); 858 859 nilfs_write_inode_common(sci->sc_root->ifile, 860 &raw_cp->cp_ifile_inode, 1); 861 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 862 return 0; 863 864 failed_ibh: 865 return err; 866 } 867 868 static void nilfs_fill_in_file_bmap(struct inode *ifile, 869 struct nilfs_inode_info *ii) 870 871 { 872 struct buffer_head *ibh; 873 struct nilfs_inode *raw_inode; 874 875 if (test_bit(NILFS_I_BMAP, &ii->i_state)) { 876 ibh = ii->i_bh; 877 BUG_ON(!ibh); 878 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino, 879 ibh); 880 nilfs_bmap_write(ii->i_bmap, raw_inode); 881 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh); 882 } 883 } 884 885 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci) 886 { 887 struct nilfs_inode_info *ii; 888 889 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) { 890 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii); 891 set_bit(NILFS_I_COLLECTED, &ii->i_state); 892 } 893 } 894 895 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci, 896 struct the_nilfs *nilfs) 897 { 898 struct buffer_head *bh_sr; 899 struct nilfs_super_root *raw_sr; 900 unsigned isz, srsz; 901 902 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root; 903 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 904 isz = nilfs->ns_inode_size; 905 srsz = NILFS_SR_BYTES(isz); 906 907 raw_sr->sr_bytes = cpu_to_le16(srsz); 908 raw_sr->sr_nongc_ctime 909 = cpu_to_le64(nilfs_doing_gc() ? 910 nilfs->ns_nongc_ctime : sci->sc_seg_ctime); 911 raw_sr->sr_flags = 0; 912 913 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr + 914 NILFS_SR_DAT_OFFSET(isz), 1); 915 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr + 916 NILFS_SR_CPFILE_OFFSET(isz), 1); 917 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr + 918 NILFS_SR_SUFILE_OFFSET(isz), 1); 919 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz); 920 } 921 922 static void nilfs_redirty_inodes(struct list_head *head) 923 { 924 struct nilfs_inode_info *ii; 925 926 list_for_each_entry(ii, head, i_dirty) { 927 if (test_bit(NILFS_I_COLLECTED, &ii->i_state)) 928 clear_bit(NILFS_I_COLLECTED, &ii->i_state); 929 } 930 } 931 932 static void nilfs_drop_collected_inodes(struct list_head *head) 933 { 934 struct nilfs_inode_info *ii; 935 936 list_for_each_entry(ii, head, i_dirty) { 937 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state)) 938 continue; 939 940 clear_bit(NILFS_I_INODE_SYNC, &ii->i_state); 941 set_bit(NILFS_I_UPDATED, &ii->i_state); 942 } 943 } 944 945 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci, 946 struct inode *inode, 947 struct list_head *listp, 948 int (*collect)(struct nilfs_sc_info *, 949 struct buffer_head *, 950 struct inode *)) 951 { 952 struct buffer_head *bh, *n; 953 int err = 0; 954 955 if (collect) { 956 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) { 957 list_del_init(&bh->b_assoc_buffers); 958 err = collect(sci, bh, inode); 959 brelse(bh); 960 if (unlikely(err)) 961 goto dispose_buffers; 962 } 963 return 0; 964 } 965 966 dispose_buffers: 967 while (!list_empty(listp)) { 968 bh = list_first_entry(listp, struct buffer_head, 969 b_assoc_buffers); 970 list_del_init(&bh->b_assoc_buffers); 971 brelse(bh); 972 } 973 return err; 974 } 975 976 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci) 977 { 978 /* Remaining number of blocks within segment buffer */ 979 return sci->sc_segbuf_nblocks - 980 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks); 981 } 982 983 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci, 984 struct inode *inode, 985 struct nilfs_sc_operations *sc_ops) 986 { 987 LIST_HEAD(data_buffers); 988 LIST_HEAD(node_buffers); 989 int err; 990 991 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { 992 size_t n, rest = nilfs_segctor_buffer_rest(sci); 993 994 n = nilfs_lookup_dirty_data_buffers( 995 inode, &data_buffers, rest + 1, 0, LLONG_MAX); 996 if (n > rest) { 997 err = nilfs_segctor_apply_buffers( 998 sci, inode, &data_buffers, 999 sc_ops->collect_data); 1000 BUG_ON(!err); /* always receive -E2BIG or true error */ 1001 goto break_or_fail; 1002 } 1003 } 1004 nilfs_lookup_dirty_node_buffers(inode, &node_buffers); 1005 1006 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { 1007 err = nilfs_segctor_apply_buffers( 1008 sci, inode, &data_buffers, sc_ops->collect_data); 1009 if (unlikely(err)) { 1010 /* dispose node list */ 1011 nilfs_segctor_apply_buffers( 1012 sci, inode, &node_buffers, NULL); 1013 goto break_or_fail; 1014 } 1015 sci->sc_stage.flags |= NILFS_CF_NODE; 1016 } 1017 /* Collect node */ 1018 err = nilfs_segctor_apply_buffers( 1019 sci, inode, &node_buffers, sc_ops->collect_node); 1020 if (unlikely(err)) 1021 goto break_or_fail; 1022 1023 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers); 1024 err = nilfs_segctor_apply_buffers( 1025 sci, inode, &node_buffers, sc_ops->collect_bmap); 1026 if (unlikely(err)) 1027 goto break_or_fail; 1028 1029 nilfs_segctor_end_finfo(sci, inode); 1030 sci->sc_stage.flags &= ~NILFS_CF_NODE; 1031 1032 break_or_fail: 1033 return err; 1034 } 1035 1036 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci, 1037 struct inode *inode) 1038 { 1039 LIST_HEAD(data_buffers); 1040 size_t n, rest = nilfs_segctor_buffer_rest(sci); 1041 int err; 1042 1043 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1, 1044 sci->sc_dsync_start, 1045 sci->sc_dsync_end); 1046 1047 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers, 1048 nilfs_collect_file_data); 1049 if (!err) { 1050 nilfs_segctor_end_finfo(sci, inode); 1051 BUG_ON(n > rest); 1052 /* always receive -E2BIG or true error if n > rest */ 1053 } 1054 return err; 1055 } 1056 1057 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode) 1058 { 1059 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1060 struct list_head *head; 1061 struct nilfs_inode_info *ii; 1062 size_t ndone; 1063 int err = 0; 1064 1065 switch (sci->sc_stage.scnt) { 1066 case NILFS_ST_INIT: 1067 /* Pre-processes */ 1068 sci->sc_stage.flags = 0; 1069 1070 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) { 1071 sci->sc_nblk_inc = 0; 1072 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN; 1073 if (mode == SC_LSEG_DSYNC) { 1074 sci->sc_stage.scnt = NILFS_ST_DSYNC; 1075 goto dsync_mode; 1076 } 1077 } 1078 1079 sci->sc_stage.dirty_file_ptr = NULL; 1080 sci->sc_stage.gc_inode_ptr = NULL; 1081 if (mode == SC_FLUSH_DAT) { 1082 sci->sc_stage.scnt = NILFS_ST_DAT; 1083 goto dat_stage; 1084 } 1085 sci->sc_stage.scnt++; /* Fall through */ 1086 case NILFS_ST_GC: 1087 if (nilfs_doing_gc()) { 1088 head = &sci->sc_gc_inodes; 1089 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr, 1090 head, i_dirty); 1091 list_for_each_entry_continue(ii, head, i_dirty) { 1092 err = nilfs_segctor_scan_file( 1093 sci, &ii->vfs_inode, 1094 &nilfs_sc_file_ops); 1095 if (unlikely(err)) { 1096 sci->sc_stage.gc_inode_ptr = list_entry( 1097 ii->i_dirty.prev, 1098 struct nilfs_inode_info, 1099 i_dirty); 1100 goto break_or_fail; 1101 } 1102 set_bit(NILFS_I_COLLECTED, &ii->i_state); 1103 } 1104 sci->sc_stage.gc_inode_ptr = NULL; 1105 } 1106 sci->sc_stage.scnt++; /* Fall through */ 1107 case NILFS_ST_FILE: 1108 head = &sci->sc_dirty_files; 1109 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head, 1110 i_dirty); 1111 list_for_each_entry_continue(ii, head, i_dirty) { 1112 clear_bit(NILFS_I_DIRTY, &ii->i_state); 1113 1114 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode, 1115 &nilfs_sc_file_ops); 1116 if (unlikely(err)) { 1117 sci->sc_stage.dirty_file_ptr = 1118 list_entry(ii->i_dirty.prev, 1119 struct nilfs_inode_info, 1120 i_dirty); 1121 goto break_or_fail; 1122 } 1123 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */ 1124 /* XXX: required ? */ 1125 } 1126 sci->sc_stage.dirty_file_ptr = NULL; 1127 if (mode == SC_FLUSH_FILE) { 1128 sci->sc_stage.scnt = NILFS_ST_DONE; 1129 return 0; 1130 } 1131 sci->sc_stage.scnt++; 1132 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED; 1133 /* Fall through */ 1134 case NILFS_ST_IFILE: 1135 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile, 1136 &nilfs_sc_file_ops); 1137 if (unlikely(err)) 1138 break; 1139 sci->sc_stage.scnt++; 1140 /* Creating a checkpoint */ 1141 err = nilfs_segctor_create_checkpoint(sci); 1142 if (unlikely(err)) 1143 break; 1144 /* Fall through */ 1145 case NILFS_ST_CPFILE: 1146 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile, 1147 &nilfs_sc_file_ops); 1148 if (unlikely(err)) 1149 break; 1150 sci->sc_stage.scnt++; /* Fall through */ 1151 case NILFS_ST_SUFILE: 1152 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs, 1153 sci->sc_nfreesegs, &ndone); 1154 if (unlikely(err)) { 1155 nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1156 sci->sc_freesegs, ndone, 1157 NULL); 1158 break; 1159 } 1160 sci->sc_stage.flags |= NILFS_CF_SUFREED; 1161 1162 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile, 1163 &nilfs_sc_file_ops); 1164 if (unlikely(err)) 1165 break; 1166 sci->sc_stage.scnt++; /* Fall through */ 1167 case NILFS_ST_DAT: 1168 dat_stage: 1169 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat, 1170 &nilfs_sc_dat_ops); 1171 if (unlikely(err)) 1172 break; 1173 if (mode == SC_FLUSH_DAT) { 1174 sci->sc_stage.scnt = NILFS_ST_DONE; 1175 return 0; 1176 } 1177 sci->sc_stage.scnt++; /* Fall through */ 1178 case NILFS_ST_SR: 1179 if (mode == SC_LSEG_SR) { 1180 /* Appending a super root */ 1181 err = nilfs_segctor_add_super_root(sci); 1182 if (unlikely(err)) 1183 break; 1184 } 1185 /* End of a logical segment */ 1186 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; 1187 sci->sc_stage.scnt = NILFS_ST_DONE; 1188 return 0; 1189 case NILFS_ST_DSYNC: 1190 dsync_mode: 1191 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT; 1192 ii = sci->sc_dsync_inode; 1193 if (!test_bit(NILFS_I_BUSY, &ii->i_state)) 1194 break; 1195 1196 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode); 1197 if (unlikely(err)) 1198 break; 1199 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; 1200 sci->sc_stage.scnt = NILFS_ST_DONE; 1201 return 0; 1202 case NILFS_ST_DONE: 1203 return 0; 1204 default: 1205 BUG(); 1206 } 1207 1208 break_or_fail: 1209 return err; 1210 } 1211 1212 /** 1213 * nilfs_segctor_begin_construction - setup segment buffer to make a new log 1214 * @sci: nilfs_sc_info 1215 * @nilfs: nilfs object 1216 */ 1217 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci, 1218 struct the_nilfs *nilfs) 1219 { 1220 struct nilfs_segment_buffer *segbuf, *prev; 1221 __u64 nextnum; 1222 int err, alloc = 0; 1223 1224 segbuf = nilfs_segbuf_new(sci->sc_super); 1225 if (unlikely(!segbuf)) 1226 return -ENOMEM; 1227 1228 if (list_empty(&sci->sc_write_logs)) { 1229 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 1230 nilfs->ns_pseg_offset, nilfs); 1231 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { 1232 nilfs_shift_to_next_segment(nilfs); 1233 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs); 1234 } 1235 1236 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq; 1237 nextnum = nilfs->ns_nextnum; 1238 1239 if (nilfs->ns_segnum == nilfs->ns_nextnum) 1240 /* Start from the head of a new full segment */ 1241 alloc++; 1242 } else { 1243 /* Continue logs */ 1244 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1245 nilfs_segbuf_map_cont(segbuf, prev); 1246 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq; 1247 nextnum = prev->sb_nextnum; 1248 1249 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { 1250 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); 1251 segbuf->sb_sum.seg_seq++; 1252 alloc++; 1253 } 1254 } 1255 1256 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum); 1257 if (err) 1258 goto failed; 1259 1260 if (alloc) { 1261 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum); 1262 if (err) 1263 goto failed; 1264 } 1265 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs); 1266 1267 BUG_ON(!list_empty(&sci->sc_segbufs)); 1268 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs); 1269 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks; 1270 return 0; 1271 1272 failed: 1273 nilfs_segbuf_free(segbuf); 1274 return err; 1275 } 1276 1277 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci, 1278 struct the_nilfs *nilfs, int nadd) 1279 { 1280 struct nilfs_segment_buffer *segbuf, *prev; 1281 struct inode *sufile = nilfs->ns_sufile; 1282 __u64 nextnextnum; 1283 LIST_HEAD(list); 1284 int err, ret, i; 1285 1286 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs); 1287 /* 1288 * Since the segment specified with nextnum might be allocated during 1289 * the previous construction, the buffer including its segusage may 1290 * not be dirty. The following call ensures that the buffer is dirty 1291 * and will pin the buffer on memory until the sufile is written. 1292 */ 1293 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum); 1294 if (unlikely(err)) 1295 return err; 1296 1297 for (i = 0; i < nadd; i++) { 1298 /* extend segment info */ 1299 err = -ENOMEM; 1300 segbuf = nilfs_segbuf_new(sci->sc_super); 1301 if (unlikely(!segbuf)) 1302 goto failed; 1303 1304 /* map this buffer to region of segment on-disk */ 1305 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); 1306 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks; 1307 1308 /* allocate the next next full segment */ 1309 err = nilfs_sufile_alloc(sufile, &nextnextnum); 1310 if (unlikely(err)) 1311 goto failed_segbuf; 1312 1313 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1; 1314 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs); 1315 1316 list_add_tail(&segbuf->sb_list, &list); 1317 prev = segbuf; 1318 } 1319 list_splice_tail(&list, &sci->sc_segbufs); 1320 return 0; 1321 1322 failed_segbuf: 1323 nilfs_segbuf_free(segbuf); 1324 failed: 1325 list_for_each_entry(segbuf, &list, sb_list) { 1326 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1327 WARN_ON(ret); /* never fails */ 1328 } 1329 nilfs_destroy_logs(&list); 1330 return err; 1331 } 1332 1333 static void nilfs_free_incomplete_logs(struct list_head *logs, 1334 struct the_nilfs *nilfs) 1335 { 1336 struct nilfs_segment_buffer *segbuf, *prev; 1337 struct inode *sufile = nilfs->ns_sufile; 1338 int ret; 1339 1340 segbuf = NILFS_FIRST_SEGBUF(logs); 1341 if (nilfs->ns_nextnum != segbuf->sb_nextnum) { 1342 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1343 WARN_ON(ret); /* never fails */ 1344 } 1345 if (atomic_read(&segbuf->sb_err)) { 1346 /* Case 1: The first segment failed */ 1347 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start) 1348 /* Case 1a: Partial segment appended into an existing 1349 segment */ 1350 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start, 1351 segbuf->sb_fseg_end); 1352 else /* Case 1b: New full segment */ 1353 set_nilfs_discontinued(nilfs); 1354 } 1355 1356 prev = segbuf; 1357 list_for_each_entry_continue(segbuf, logs, sb_list) { 1358 if (prev->sb_nextnum != segbuf->sb_nextnum) { 1359 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1360 WARN_ON(ret); /* never fails */ 1361 } 1362 if (atomic_read(&segbuf->sb_err) && 1363 segbuf->sb_segnum != nilfs->ns_nextnum) 1364 /* Case 2: extended segment (!= next) failed */ 1365 nilfs_sufile_set_error(sufile, segbuf->sb_segnum); 1366 prev = segbuf; 1367 } 1368 } 1369 1370 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci, 1371 struct inode *sufile) 1372 { 1373 struct nilfs_segment_buffer *segbuf; 1374 unsigned long live_blocks; 1375 int ret; 1376 1377 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1378 live_blocks = segbuf->sb_sum.nblocks + 1379 (segbuf->sb_pseg_start - segbuf->sb_fseg_start); 1380 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1381 live_blocks, 1382 sci->sc_seg_ctime); 1383 WARN_ON(ret); /* always succeed because the segusage is dirty */ 1384 } 1385 } 1386 1387 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile) 1388 { 1389 struct nilfs_segment_buffer *segbuf; 1390 int ret; 1391 1392 segbuf = NILFS_FIRST_SEGBUF(logs); 1393 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1394 segbuf->sb_pseg_start - 1395 segbuf->sb_fseg_start, 0); 1396 WARN_ON(ret); /* always succeed because the segusage is dirty */ 1397 1398 list_for_each_entry_continue(segbuf, logs, sb_list) { 1399 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1400 0, 0); 1401 WARN_ON(ret); /* always succeed */ 1402 } 1403 } 1404 1405 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci, 1406 struct nilfs_segment_buffer *last, 1407 struct inode *sufile) 1408 { 1409 struct nilfs_segment_buffer *segbuf = last; 1410 int ret; 1411 1412 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) { 1413 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks; 1414 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1415 WARN_ON(ret); 1416 } 1417 nilfs_truncate_logs(&sci->sc_segbufs, last); 1418 } 1419 1420 1421 static int nilfs_segctor_collect(struct nilfs_sc_info *sci, 1422 struct the_nilfs *nilfs, int mode) 1423 { 1424 struct nilfs_cstage prev_stage = sci->sc_stage; 1425 int err, nadd = 1; 1426 1427 /* Collection retry loop */ 1428 for (;;) { 1429 sci->sc_nblk_this_inc = 0; 1430 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs); 1431 1432 err = nilfs_segctor_reset_segment_buffer(sci); 1433 if (unlikely(err)) 1434 goto failed; 1435 1436 err = nilfs_segctor_collect_blocks(sci, mode); 1437 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; 1438 if (!err) 1439 break; 1440 1441 if (unlikely(err != -E2BIG)) 1442 goto failed; 1443 1444 /* The current segment is filled up */ 1445 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE) 1446 break; 1447 1448 nilfs_clear_logs(&sci->sc_segbufs); 1449 1450 if (sci->sc_stage.flags & NILFS_CF_SUFREED) { 1451 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1452 sci->sc_freesegs, 1453 sci->sc_nfreesegs, 1454 NULL); 1455 WARN_ON(err); /* do not happen */ 1456 sci->sc_stage.flags &= ~NILFS_CF_SUFREED; 1457 } 1458 1459 err = nilfs_segctor_extend_segments(sci, nilfs, nadd); 1460 if (unlikely(err)) 1461 return err; 1462 1463 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA); 1464 sci->sc_stage = prev_stage; 1465 } 1466 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile); 1467 return 0; 1468 1469 failed: 1470 return err; 1471 } 1472 1473 static void nilfs_list_replace_buffer(struct buffer_head *old_bh, 1474 struct buffer_head *new_bh) 1475 { 1476 BUG_ON(!list_empty(&new_bh->b_assoc_buffers)); 1477 1478 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers); 1479 /* The caller must release old_bh */ 1480 } 1481 1482 static int 1483 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci, 1484 struct nilfs_segment_buffer *segbuf, 1485 int mode) 1486 { 1487 struct inode *inode = NULL; 1488 sector_t blocknr; 1489 unsigned long nfinfo = segbuf->sb_sum.nfinfo; 1490 unsigned long nblocks = 0, ndatablk = 0; 1491 struct nilfs_sc_operations *sc_op = NULL; 1492 struct nilfs_segsum_pointer ssp; 1493 struct nilfs_finfo *finfo = NULL; 1494 union nilfs_binfo binfo; 1495 struct buffer_head *bh, *bh_org; 1496 ino_t ino = 0; 1497 int err = 0; 1498 1499 if (!nfinfo) 1500 goto out; 1501 1502 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk; 1503 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); 1504 ssp.offset = sizeof(struct nilfs_segment_summary); 1505 1506 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { 1507 if (bh == segbuf->sb_super_root) 1508 break; 1509 if (!finfo) { 1510 finfo = nilfs_segctor_map_segsum_entry( 1511 sci, &ssp, sizeof(*finfo)); 1512 ino = le64_to_cpu(finfo->fi_ino); 1513 nblocks = le32_to_cpu(finfo->fi_nblocks); 1514 ndatablk = le32_to_cpu(finfo->fi_ndatablk); 1515 1516 inode = bh->b_page->mapping->host; 1517 1518 if (mode == SC_LSEG_DSYNC) 1519 sc_op = &nilfs_sc_dsync_ops; 1520 else if (ino == NILFS_DAT_INO) 1521 sc_op = &nilfs_sc_dat_ops; 1522 else /* file blocks */ 1523 sc_op = &nilfs_sc_file_ops; 1524 } 1525 bh_org = bh; 1526 get_bh(bh_org); 1527 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr, 1528 &binfo); 1529 if (bh != bh_org) 1530 nilfs_list_replace_buffer(bh_org, bh); 1531 brelse(bh_org); 1532 if (unlikely(err)) 1533 goto failed_bmap; 1534 1535 if (ndatablk > 0) 1536 sc_op->write_data_binfo(sci, &ssp, &binfo); 1537 else 1538 sc_op->write_node_binfo(sci, &ssp, &binfo); 1539 1540 blocknr++; 1541 if (--nblocks == 0) { 1542 finfo = NULL; 1543 if (--nfinfo == 0) 1544 break; 1545 } else if (ndatablk > 0) 1546 ndatablk--; 1547 } 1548 out: 1549 return 0; 1550 1551 failed_bmap: 1552 return err; 1553 } 1554 1555 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode) 1556 { 1557 struct nilfs_segment_buffer *segbuf; 1558 int err; 1559 1560 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1561 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode); 1562 if (unlikely(err)) 1563 return err; 1564 nilfs_segbuf_fill_in_segsum(segbuf); 1565 } 1566 return 0; 1567 } 1568 1569 static void nilfs_begin_page_io(struct page *page) 1570 { 1571 if (!page || PageWriteback(page)) 1572 /* For split b-tree node pages, this function may be called 1573 twice. We ignore the 2nd or later calls by this check. */ 1574 return; 1575 1576 lock_page(page); 1577 clear_page_dirty_for_io(page); 1578 set_page_writeback(page); 1579 unlock_page(page); 1580 } 1581 1582 static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) 1583 { 1584 struct nilfs_segment_buffer *segbuf; 1585 struct page *bd_page = NULL, *fs_page = NULL; 1586 1587 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1588 struct buffer_head *bh; 1589 1590 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1591 b_assoc_buffers) { 1592 if (bh->b_page != bd_page) { 1593 if (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 } 1599 bd_page = bh->b_page; 1600 } 1601 } 1602 1603 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1604 b_assoc_buffers) { 1605 set_buffer_async_write(bh); 1606 if (bh == segbuf->sb_super_root) { 1607 if (bh->b_page != bd_page) { 1608 lock_page(bd_page); 1609 clear_page_dirty_for_io(bd_page); 1610 set_page_writeback(bd_page); 1611 unlock_page(bd_page); 1612 bd_page = bh->b_page; 1613 } 1614 break; 1615 } 1616 if (bh->b_page != fs_page) { 1617 nilfs_begin_page_io(fs_page); 1618 fs_page = bh->b_page; 1619 } 1620 } 1621 } 1622 if (bd_page) { 1623 lock_page(bd_page); 1624 clear_page_dirty_for_io(bd_page); 1625 set_page_writeback(bd_page); 1626 unlock_page(bd_page); 1627 } 1628 nilfs_begin_page_io(fs_page); 1629 } 1630 1631 static int nilfs_segctor_write(struct nilfs_sc_info *sci, 1632 struct the_nilfs *nilfs) 1633 { 1634 int ret; 1635 1636 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs); 1637 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs); 1638 return ret; 1639 } 1640 1641 static void nilfs_end_page_io(struct page *page, int err) 1642 { 1643 if (!page) 1644 return; 1645 1646 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) { 1647 /* 1648 * For b-tree node pages, this function may be called twice 1649 * or more because they might be split in a segment. 1650 */ 1651 if (PageDirty(page)) { 1652 /* 1653 * For pages holding split b-tree node buffers, dirty 1654 * flag on the buffers may be cleared discretely. 1655 * In that case, the page is once redirtied for 1656 * remaining buffers, and it must be cancelled if 1657 * all the buffers get cleaned later. 1658 */ 1659 lock_page(page); 1660 if (nilfs_page_buffers_clean(page)) 1661 __nilfs_clear_page_dirty(page); 1662 unlock_page(page); 1663 } 1664 return; 1665 } 1666 1667 if (!err) { 1668 if (!nilfs_page_buffers_clean(page)) 1669 __set_page_dirty_nobuffers(page); 1670 ClearPageError(page); 1671 } else { 1672 __set_page_dirty_nobuffers(page); 1673 SetPageError(page); 1674 } 1675 1676 end_page_writeback(page); 1677 } 1678 1679 static void nilfs_abort_logs(struct list_head *logs, int err) 1680 { 1681 struct nilfs_segment_buffer *segbuf; 1682 struct page *bd_page = NULL, *fs_page = NULL; 1683 struct buffer_head *bh; 1684 1685 if (list_empty(logs)) 1686 return; 1687 1688 list_for_each_entry(segbuf, logs, sb_list) { 1689 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1690 b_assoc_buffers) { 1691 if (bh->b_page != bd_page) { 1692 if (bd_page) 1693 end_page_writeback(bd_page); 1694 bd_page = bh->b_page; 1695 } 1696 } 1697 1698 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1699 b_assoc_buffers) { 1700 clear_buffer_async_write(bh); 1701 if (bh == segbuf->sb_super_root) { 1702 if (bh->b_page != bd_page) { 1703 end_page_writeback(bd_page); 1704 bd_page = bh->b_page; 1705 } 1706 break; 1707 } 1708 if (bh->b_page != fs_page) { 1709 nilfs_end_page_io(fs_page, err); 1710 fs_page = bh->b_page; 1711 } 1712 } 1713 } 1714 if (bd_page) 1715 end_page_writeback(bd_page); 1716 1717 nilfs_end_page_io(fs_page, err); 1718 } 1719 1720 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci, 1721 struct the_nilfs *nilfs, int err) 1722 { 1723 LIST_HEAD(logs); 1724 int ret; 1725 1726 list_splice_tail_init(&sci->sc_write_logs, &logs); 1727 ret = nilfs_wait_on_logs(&logs); 1728 nilfs_abort_logs(&logs, ret ? : err); 1729 1730 list_splice_tail_init(&sci->sc_segbufs, &logs); 1731 nilfs_cancel_segusage(&logs, nilfs->ns_sufile); 1732 nilfs_free_incomplete_logs(&logs, nilfs); 1733 1734 if (sci->sc_stage.flags & NILFS_CF_SUFREED) { 1735 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1736 sci->sc_freesegs, 1737 sci->sc_nfreesegs, 1738 NULL); 1739 WARN_ON(ret); /* do not happen */ 1740 } 1741 1742 nilfs_destroy_logs(&logs); 1743 } 1744 1745 static void nilfs_set_next_segment(struct the_nilfs *nilfs, 1746 struct nilfs_segment_buffer *segbuf) 1747 { 1748 nilfs->ns_segnum = segbuf->sb_segnum; 1749 nilfs->ns_nextnum = segbuf->sb_nextnum; 1750 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start 1751 + segbuf->sb_sum.nblocks; 1752 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq; 1753 nilfs->ns_ctime = segbuf->sb_sum.ctime; 1754 } 1755 1756 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) 1757 { 1758 struct nilfs_segment_buffer *segbuf; 1759 struct page *bd_page = NULL, *fs_page = NULL; 1760 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1761 int update_sr = false; 1762 1763 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) { 1764 struct buffer_head *bh; 1765 1766 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1767 b_assoc_buffers) { 1768 set_buffer_uptodate(bh); 1769 clear_buffer_dirty(bh); 1770 if (bh->b_page != bd_page) { 1771 if (bd_page) 1772 end_page_writeback(bd_page); 1773 bd_page = bh->b_page; 1774 } 1775 } 1776 /* 1777 * We assume that the buffers which belong to the same page 1778 * continue over the buffer list. 1779 * Under this assumption, the last BHs of pages is 1780 * identifiable by the discontinuity of bh->b_page 1781 * (page != fs_page). 1782 * 1783 * For B-tree node blocks, however, this assumption is not 1784 * guaranteed. The cleanup code of B-tree node pages needs 1785 * special care. 1786 */ 1787 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1788 b_assoc_buffers) { 1789 const unsigned long set_bits = (1 << BH_Uptodate); 1790 const unsigned long clear_bits = 1791 (1 << BH_Dirty | 1 << BH_Async_Write | 1792 1 << BH_Delay | 1 << BH_NILFS_Volatile | 1793 1 << BH_NILFS_Redirected); 1794 1795 set_mask_bits(&bh->b_state, clear_bits, set_bits); 1796 if (bh == segbuf->sb_super_root) { 1797 if (bh->b_page != bd_page) { 1798 end_page_writeback(bd_page); 1799 bd_page = bh->b_page; 1800 } 1801 update_sr = true; 1802 break; 1803 } 1804 if (bh->b_page != fs_page) { 1805 nilfs_end_page_io(fs_page, 0); 1806 fs_page = bh->b_page; 1807 } 1808 } 1809 1810 if (!nilfs_segbuf_simplex(segbuf)) { 1811 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) { 1812 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1813 sci->sc_lseg_stime = jiffies; 1814 } 1815 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND) 1816 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1817 } 1818 } 1819 /* 1820 * Since pages may continue over multiple segment buffers, 1821 * end of the last page must be checked outside of the loop. 1822 */ 1823 if (bd_page) 1824 end_page_writeback(bd_page); 1825 1826 nilfs_end_page_io(fs_page, 0); 1827 1828 nilfs_drop_collected_inodes(&sci->sc_dirty_files); 1829 1830 if (nilfs_doing_gc()) 1831 nilfs_drop_collected_inodes(&sci->sc_gc_inodes); 1832 else 1833 nilfs->ns_nongc_ctime = sci->sc_seg_ctime; 1834 1835 sci->sc_nblk_inc += sci->sc_nblk_this_inc; 1836 1837 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1838 nilfs_set_next_segment(nilfs, segbuf); 1839 1840 if (update_sr) { 1841 nilfs->ns_flushed_device = 0; 1842 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start, 1843 segbuf->sb_sum.seg_seq, nilfs->ns_cno++); 1844 1845 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 1846 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags); 1847 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1848 nilfs_segctor_clear_metadata_dirty(sci); 1849 } else 1850 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1851 } 1852 1853 static int nilfs_segctor_wait(struct nilfs_sc_info *sci) 1854 { 1855 int ret; 1856 1857 ret = nilfs_wait_on_logs(&sci->sc_write_logs); 1858 if (!ret) { 1859 nilfs_segctor_complete_write(sci); 1860 nilfs_destroy_logs(&sci->sc_write_logs); 1861 } 1862 return ret; 1863 } 1864 1865 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci, 1866 struct the_nilfs *nilfs) 1867 { 1868 struct nilfs_inode_info *ii, *n; 1869 struct inode *ifile = sci->sc_root->ifile; 1870 1871 spin_lock(&nilfs->ns_inode_lock); 1872 retry: 1873 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) { 1874 if (!ii->i_bh) { 1875 struct buffer_head *ibh; 1876 int err; 1877 1878 spin_unlock(&nilfs->ns_inode_lock); 1879 err = nilfs_ifile_get_inode_block( 1880 ifile, ii->vfs_inode.i_ino, &ibh); 1881 if (unlikely(err)) { 1882 nilfs_warning(sci->sc_super, __func__, 1883 "failed to get inode block.\n"); 1884 return err; 1885 } 1886 mark_buffer_dirty(ibh); 1887 nilfs_mdt_mark_dirty(ifile); 1888 spin_lock(&nilfs->ns_inode_lock); 1889 if (likely(!ii->i_bh)) 1890 ii->i_bh = ibh; 1891 else 1892 brelse(ibh); 1893 goto retry; 1894 } 1895 1896 clear_bit(NILFS_I_QUEUED, &ii->i_state); 1897 set_bit(NILFS_I_BUSY, &ii->i_state); 1898 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files); 1899 } 1900 spin_unlock(&nilfs->ns_inode_lock); 1901 1902 return 0; 1903 } 1904 1905 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci, 1906 struct the_nilfs *nilfs) 1907 { 1908 struct nilfs_inode_info *ii, *n; 1909 int during_mount = !(sci->sc_super->s_flags & MS_ACTIVE); 1910 int defer_iput = false; 1911 1912 spin_lock(&nilfs->ns_inode_lock); 1913 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) { 1914 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) || 1915 test_bit(NILFS_I_DIRTY, &ii->i_state)) 1916 continue; 1917 1918 clear_bit(NILFS_I_BUSY, &ii->i_state); 1919 brelse(ii->i_bh); 1920 ii->i_bh = NULL; 1921 list_del_init(&ii->i_dirty); 1922 if (!ii->vfs_inode.i_nlink || during_mount) { 1923 /* 1924 * Defer calling iput() to avoid deadlocks if 1925 * i_nlink == 0 or mount is not yet finished. 1926 */ 1927 list_add_tail(&ii->i_dirty, &sci->sc_iput_queue); 1928 defer_iput = true; 1929 } else { 1930 spin_unlock(&nilfs->ns_inode_lock); 1931 iput(&ii->vfs_inode); 1932 spin_lock(&nilfs->ns_inode_lock); 1933 } 1934 } 1935 spin_unlock(&nilfs->ns_inode_lock); 1936 1937 if (defer_iput) 1938 schedule_work(&sci->sc_iput_work); 1939 } 1940 1941 /* 1942 * Main procedure of segment constructor 1943 */ 1944 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) 1945 { 1946 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1947 int err; 1948 1949 sci->sc_stage.scnt = NILFS_ST_INIT; 1950 sci->sc_cno = nilfs->ns_cno; 1951 1952 err = nilfs_segctor_collect_dirty_files(sci, nilfs); 1953 if (unlikely(err)) 1954 goto out; 1955 1956 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 1957 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 1958 1959 if (nilfs_segctor_clean(sci)) 1960 goto out; 1961 1962 do { 1963 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK; 1964 1965 err = nilfs_segctor_begin_construction(sci, nilfs); 1966 if (unlikely(err)) 1967 goto out; 1968 1969 /* Update time stamp */ 1970 sci->sc_seg_ctime = get_seconds(); 1971 1972 err = nilfs_segctor_collect(sci, nilfs, mode); 1973 if (unlikely(err)) 1974 goto failed; 1975 1976 /* Avoid empty segment */ 1977 if (sci->sc_stage.scnt == NILFS_ST_DONE && 1978 nilfs_segbuf_empty(sci->sc_curseg)) { 1979 nilfs_segctor_abort_construction(sci, nilfs, 1); 1980 goto out; 1981 } 1982 1983 err = nilfs_segctor_assign(sci, mode); 1984 if (unlikely(err)) 1985 goto failed; 1986 1987 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 1988 nilfs_segctor_fill_in_file_bmap(sci); 1989 1990 if (mode == SC_LSEG_SR && 1991 sci->sc_stage.scnt >= NILFS_ST_CPFILE) { 1992 err = nilfs_segctor_fill_in_checkpoint(sci); 1993 if (unlikely(err)) 1994 goto failed_to_write; 1995 1996 nilfs_segctor_fill_in_super_root(sci, nilfs); 1997 } 1998 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile); 1999 2000 /* Write partial segments */ 2001 nilfs_segctor_prepare_write(sci); 2002 2003 nilfs_add_checksums_on_logs(&sci->sc_segbufs, 2004 nilfs->ns_crc_seed); 2005 2006 err = nilfs_segctor_write(sci, nilfs); 2007 if (unlikely(err)) 2008 goto failed_to_write; 2009 2010 if (sci->sc_stage.scnt == NILFS_ST_DONE || 2011 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) { 2012 /* 2013 * At this point, we avoid double buffering 2014 * for blocksize < pagesize because page dirty 2015 * flag is turned off during write and dirty 2016 * buffers are not properly collected for 2017 * pages crossing over segments. 2018 */ 2019 err = nilfs_segctor_wait(sci); 2020 if (err) 2021 goto failed_to_write; 2022 } 2023 } while (sci->sc_stage.scnt != NILFS_ST_DONE); 2024 2025 out: 2026 nilfs_segctor_drop_written_files(sci, nilfs); 2027 return err; 2028 2029 failed_to_write: 2030 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 2031 nilfs_redirty_inodes(&sci->sc_dirty_files); 2032 2033 failed: 2034 if (nilfs_doing_gc()) 2035 nilfs_redirty_inodes(&sci->sc_gc_inodes); 2036 nilfs_segctor_abort_construction(sci, nilfs, err); 2037 goto out; 2038 } 2039 2040 /** 2041 * nilfs_segctor_start_timer - set timer of background write 2042 * @sci: nilfs_sc_info 2043 * 2044 * If the timer has already been set, it ignores the new request. 2045 * This function MUST be called within a section locking the segment 2046 * semaphore. 2047 */ 2048 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci) 2049 { 2050 spin_lock(&sci->sc_state_lock); 2051 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) { 2052 sci->sc_timer.expires = jiffies + sci->sc_interval; 2053 add_timer(&sci->sc_timer); 2054 sci->sc_state |= NILFS_SEGCTOR_COMMIT; 2055 } 2056 spin_unlock(&sci->sc_state_lock); 2057 } 2058 2059 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn) 2060 { 2061 spin_lock(&sci->sc_state_lock); 2062 if (!(sci->sc_flush_request & (1 << bn))) { 2063 unsigned long prev_req = sci->sc_flush_request; 2064 2065 sci->sc_flush_request |= (1 << bn); 2066 if (!prev_req) 2067 wake_up(&sci->sc_wait_daemon); 2068 } 2069 spin_unlock(&sci->sc_state_lock); 2070 } 2071 2072 /** 2073 * nilfs_flush_segment - trigger a segment construction for resource control 2074 * @sb: super block 2075 * @ino: inode number of the file to be flushed out. 2076 */ 2077 void nilfs_flush_segment(struct super_block *sb, ino_t ino) 2078 { 2079 struct the_nilfs *nilfs = sb->s_fs_info; 2080 struct nilfs_sc_info *sci = nilfs->ns_writer; 2081 2082 if (!sci || nilfs_doing_construction()) 2083 return; 2084 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0); 2085 /* assign bit 0 to data files */ 2086 } 2087 2088 struct nilfs_segctor_wait_request { 2089 wait_queue_t wq; 2090 __u32 seq; 2091 int err; 2092 atomic_t done; 2093 }; 2094 2095 static int nilfs_segctor_sync(struct nilfs_sc_info *sci) 2096 { 2097 struct nilfs_segctor_wait_request wait_req; 2098 int err = 0; 2099 2100 spin_lock(&sci->sc_state_lock); 2101 init_wait(&wait_req.wq); 2102 wait_req.err = 0; 2103 atomic_set(&wait_req.done, 0); 2104 wait_req.seq = ++sci->sc_seq_request; 2105 spin_unlock(&sci->sc_state_lock); 2106 2107 init_waitqueue_entry(&wait_req.wq, current); 2108 add_wait_queue(&sci->sc_wait_request, &wait_req.wq); 2109 set_current_state(TASK_INTERRUPTIBLE); 2110 wake_up(&sci->sc_wait_daemon); 2111 2112 for (;;) { 2113 if (atomic_read(&wait_req.done)) { 2114 err = wait_req.err; 2115 break; 2116 } 2117 if (!signal_pending(current)) { 2118 schedule(); 2119 continue; 2120 } 2121 err = -ERESTARTSYS; 2122 break; 2123 } 2124 finish_wait(&sci->sc_wait_request, &wait_req.wq); 2125 return err; 2126 } 2127 2128 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err) 2129 { 2130 struct nilfs_segctor_wait_request *wrq, *n; 2131 unsigned long flags; 2132 2133 spin_lock_irqsave(&sci->sc_wait_request.lock, flags); 2134 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list, 2135 wq.task_list) { 2136 if (!atomic_read(&wrq->done) && 2137 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) { 2138 wrq->err = err; 2139 atomic_set(&wrq->done, 1); 2140 } 2141 if (atomic_read(&wrq->done)) { 2142 wrq->wq.func(&wrq->wq, 2143 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 2144 0, NULL); 2145 } 2146 } 2147 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags); 2148 } 2149 2150 /** 2151 * nilfs_construct_segment - construct a logical segment 2152 * @sb: super block 2153 * 2154 * Return Value: On success, 0 is retured. On errors, one of the following 2155 * negative error code is returned. 2156 * 2157 * %-EROFS - Read only filesystem. 2158 * 2159 * %-EIO - I/O error 2160 * 2161 * %-ENOSPC - No space left on device (only in a panic state). 2162 * 2163 * %-ERESTARTSYS - Interrupted. 2164 * 2165 * %-ENOMEM - Insufficient memory available. 2166 */ 2167 int nilfs_construct_segment(struct super_block *sb) 2168 { 2169 struct the_nilfs *nilfs = sb->s_fs_info; 2170 struct nilfs_sc_info *sci = nilfs->ns_writer; 2171 struct nilfs_transaction_info *ti; 2172 int err; 2173 2174 if (!sci) 2175 return -EROFS; 2176 2177 /* A call inside transactions causes a deadlock. */ 2178 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC); 2179 2180 err = nilfs_segctor_sync(sci); 2181 return err; 2182 } 2183 2184 /** 2185 * nilfs_construct_dsync_segment - construct a data-only logical segment 2186 * @sb: super block 2187 * @inode: inode whose data blocks should be written out 2188 * @start: start byte offset 2189 * @end: end byte offset (inclusive) 2190 * 2191 * Return Value: On success, 0 is retured. On errors, one of the following 2192 * negative error code is returned. 2193 * 2194 * %-EROFS - Read only filesystem. 2195 * 2196 * %-EIO - I/O error 2197 * 2198 * %-ENOSPC - No space left on device (only in a panic state). 2199 * 2200 * %-ERESTARTSYS - Interrupted. 2201 * 2202 * %-ENOMEM - Insufficient memory available. 2203 */ 2204 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode, 2205 loff_t start, loff_t end) 2206 { 2207 struct the_nilfs *nilfs = sb->s_fs_info; 2208 struct nilfs_sc_info *sci = nilfs->ns_writer; 2209 struct nilfs_inode_info *ii; 2210 struct nilfs_transaction_info ti; 2211 int err = 0; 2212 2213 if (!sci) 2214 return -EROFS; 2215 2216 nilfs_transaction_lock(sb, &ti, 0); 2217 2218 ii = NILFS_I(inode); 2219 if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) || 2220 nilfs_test_opt(nilfs, STRICT_ORDER) || 2221 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2222 nilfs_discontinued(nilfs)) { 2223 nilfs_transaction_unlock(sb); 2224 err = nilfs_segctor_sync(sci); 2225 return err; 2226 } 2227 2228 spin_lock(&nilfs->ns_inode_lock); 2229 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) && 2230 !test_bit(NILFS_I_BUSY, &ii->i_state)) { 2231 spin_unlock(&nilfs->ns_inode_lock); 2232 nilfs_transaction_unlock(sb); 2233 return 0; 2234 } 2235 spin_unlock(&nilfs->ns_inode_lock); 2236 sci->sc_dsync_inode = ii; 2237 sci->sc_dsync_start = start; 2238 sci->sc_dsync_end = end; 2239 2240 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC); 2241 if (!err) 2242 nilfs->ns_flushed_device = 0; 2243 2244 nilfs_transaction_unlock(sb); 2245 return err; 2246 } 2247 2248 #define FLUSH_FILE_BIT (0x1) /* data file only */ 2249 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */ 2250 2251 /** 2252 * nilfs_segctor_accept - record accepted sequence count of log-write requests 2253 * @sci: segment constructor object 2254 */ 2255 static void nilfs_segctor_accept(struct nilfs_sc_info *sci) 2256 { 2257 spin_lock(&sci->sc_state_lock); 2258 sci->sc_seq_accepted = sci->sc_seq_request; 2259 spin_unlock(&sci->sc_state_lock); 2260 del_timer_sync(&sci->sc_timer); 2261 } 2262 2263 /** 2264 * nilfs_segctor_notify - notify the result of request to caller threads 2265 * @sci: segment constructor object 2266 * @mode: mode of log forming 2267 * @err: error code to be notified 2268 */ 2269 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err) 2270 { 2271 /* Clear requests (even when the construction failed) */ 2272 spin_lock(&sci->sc_state_lock); 2273 2274 if (mode == SC_LSEG_SR) { 2275 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT; 2276 sci->sc_seq_done = sci->sc_seq_accepted; 2277 nilfs_segctor_wakeup(sci, err); 2278 sci->sc_flush_request = 0; 2279 } else { 2280 if (mode == SC_FLUSH_FILE) 2281 sci->sc_flush_request &= ~FLUSH_FILE_BIT; 2282 else if (mode == SC_FLUSH_DAT) 2283 sci->sc_flush_request &= ~FLUSH_DAT_BIT; 2284 2285 /* re-enable timer if checkpoint creation was not done */ 2286 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2287 time_before(jiffies, sci->sc_timer.expires)) 2288 add_timer(&sci->sc_timer); 2289 } 2290 spin_unlock(&sci->sc_state_lock); 2291 } 2292 2293 /** 2294 * nilfs_segctor_construct - form logs and write them to disk 2295 * @sci: segment constructor object 2296 * @mode: mode of log forming 2297 */ 2298 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode) 2299 { 2300 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2301 struct nilfs_super_block **sbp; 2302 int err = 0; 2303 2304 nilfs_segctor_accept(sci); 2305 2306 if (nilfs_discontinued(nilfs)) 2307 mode = SC_LSEG_SR; 2308 if (!nilfs_segctor_confirm(sci)) 2309 err = nilfs_segctor_do_construct(sci, mode); 2310 2311 if (likely(!err)) { 2312 if (mode != SC_FLUSH_DAT) 2313 atomic_set(&nilfs->ns_ndirtyblks, 0); 2314 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) && 2315 nilfs_discontinued(nilfs)) { 2316 down_write(&nilfs->ns_sem); 2317 err = -EIO; 2318 sbp = nilfs_prepare_super(sci->sc_super, 2319 nilfs_sb_will_flip(nilfs)); 2320 if (likely(sbp)) { 2321 nilfs_set_log_cursor(sbp[0], nilfs); 2322 err = nilfs_commit_super(sci->sc_super, 2323 NILFS_SB_COMMIT); 2324 } 2325 up_write(&nilfs->ns_sem); 2326 } 2327 } 2328 2329 nilfs_segctor_notify(sci, mode, err); 2330 return err; 2331 } 2332 2333 static void nilfs_construction_timeout(unsigned long data) 2334 { 2335 struct task_struct *p = (struct task_struct *)data; 2336 wake_up_process(p); 2337 } 2338 2339 static void 2340 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head) 2341 { 2342 struct nilfs_inode_info *ii, *n; 2343 2344 list_for_each_entry_safe(ii, n, head, i_dirty) { 2345 if (!test_bit(NILFS_I_UPDATED, &ii->i_state)) 2346 continue; 2347 list_del_init(&ii->i_dirty); 2348 truncate_inode_pages(&ii->vfs_inode.i_data, 0); 2349 nilfs_btnode_cache_clear(&ii->i_btnode_cache); 2350 iput(&ii->vfs_inode); 2351 } 2352 } 2353 2354 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv, 2355 void **kbufs) 2356 { 2357 struct the_nilfs *nilfs = sb->s_fs_info; 2358 struct nilfs_sc_info *sci = nilfs->ns_writer; 2359 struct nilfs_transaction_info ti; 2360 int err; 2361 2362 if (unlikely(!sci)) 2363 return -EROFS; 2364 2365 nilfs_transaction_lock(sb, &ti, 1); 2366 2367 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat); 2368 if (unlikely(err)) 2369 goto out_unlock; 2370 2371 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs); 2372 if (unlikely(err)) { 2373 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat); 2374 goto out_unlock; 2375 } 2376 2377 sci->sc_freesegs = kbufs[4]; 2378 sci->sc_nfreesegs = argv[4].v_nmembs; 2379 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes); 2380 2381 for (;;) { 2382 err = nilfs_segctor_construct(sci, SC_LSEG_SR); 2383 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes); 2384 2385 if (likely(!err)) 2386 break; 2387 2388 nilfs_warning(sb, __func__, 2389 "segment construction failed. (err=%d)", err); 2390 set_current_state(TASK_INTERRUPTIBLE); 2391 schedule_timeout(sci->sc_interval); 2392 } 2393 if (nilfs_test_opt(nilfs, DISCARD)) { 2394 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs, 2395 sci->sc_nfreesegs); 2396 if (ret) { 2397 printk(KERN_WARNING 2398 "NILFS warning: error %d on discard request, " 2399 "turning discards off for the device\n", ret); 2400 nilfs_clear_opt(nilfs, DISCARD); 2401 } 2402 } 2403 2404 out_unlock: 2405 sci->sc_freesegs = NULL; 2406 sci->sc_nfreesegs = 0; 2407 nilfs_mdt_clear_shadow_map(nilfs->ns_dat); 2408 nilfs_transaction_unlock(sb); 2409 return err; 2410 } 2411 2412 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode) 2413 { 2414 struct nilfs_transaction_info ti; 2415 2416 nilfs_transaction_lock(sci->sc_super, &ti, 0); 2417 nilfs_segctor_construct(sci, mode); 2418 2419 /* 2420 * Unclosed segment should be retried. We do this using sc_timer. 2421 * Timeout of sc_timer will invoke complete construction which leads 2422 * to close the current logical segment. 2423 */ 2424 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) 2425 nilfs_segctor_start_timer(sci); 2426 2427 nilfs_transaction_unlock(sci->sc_super); 2428 } 2429 2430 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci) 2431 { 2432 int mode = 0; 2433 int err; 2434 2435 spin_lock(&sci->sc_state_lock); 2436 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ? 2437 SC_FLUSH_DAT : SC_FLUSH_FILE; 2438 spin_unlock(&sci->sc_state_lock); 2439 2440 if (mode) { 2441 err = nilfs_segctor_do_construct(sci, mode); 2442 2443 spin_lock(&sci->sc_state_lock); 2444 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ? 2445 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT; 2446 spin_unlock(&sci->sc_state_lock); 2447 } 2448 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 2449 } 2450 2451 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci) 2452 { 2453 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2454 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) { 2455 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT)) 2456 return SC_FLUSH_FILE; 2457 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT)) 2458 return SC_FLUSH_DAT; 2459 } 2460 return SC_LSEG_SR; 2461 } 2462 2463 /** 2464 * nilfs_segctor_thread - main loop of the segment constructor thread. 2465 * @arg: pointer to a struct nilfs_sc_info. 2466 * 2467 * nilfs_segctor_thread() initializes a timer and serves as a daemon 2468 * to execute segment constructions. 2469 */ 2470 static int nilfs_segctor_thread(void *arg) 2471 { 2472 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg; 2473 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2474 int timeout = 0; 2475 2476 sci->sc_timer.data = (unsigned long)current; 2477 sci->sc_timer.function = nilfs_construction_timeout; 2478 2479 /* start sync. */ 2480 sci->sc_task = current; 2481 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */ 2482 printk(KERN_INFO 2483 "segctord starting. Construction interval = %lu seconds, " 2484 "CP frequency < %lu seconds\n", 2485 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ); 2486 2487 spin_lock(&sci->sc_state_lock); 2488 loop: 2489 for (;;) { 2490 int mode; 2491 2492 if (sci->sc_state & NILFS_SEGCTOR_QUIT) 2493 goto end_thread; 2494 2495 if (timeout || sci->sc_seq_request != sci->sc_seq_done) 2496 mode = SC_LSEG_SR; 2497 else if (!sci->sc_flush_request) 2498 break; 2499 else 2500 mode = nilfs_segctor_flush_mode(sci); 2501 2502 spin_unlock(&sci->sc_state_lock); 2503 nilfs_segctor_thread_construct(sci, mode); 2504 spin_lock(&sci->sc_state_lock); 2505 timeout = 0; 2506 } 2507 2508 2509 if (freezing(current)) { 2510 spin_unlock(&sci->sc_state_lock); 2511 try_to_freeze(); 2512 spin_lock(&sci->sc_state_lock); 2513 } else { 2514 DEFINE_WAIT(wait); 2515 int should_sleep = 1; 2516 2517 prepare_to_wait(&sci->sc_wait_daemon, &wait, 2518 TASK_INTERRUPTIBLE); 2519 2520 if (sci->sc_seq_request != sci->sc_seq_done) 2521 should_sleep = 0; 2522 else if (sci->sc_flush_request) 2523 should_sleep = 0; 2524 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT) 2525 should_sleep = time_before(jiffies, 2526 sci->sc_timer.expires); 2527 2528 if (should_sleep) { 2529 spin_unlock(&sci->sc_state_lock); 2530 schedule(); 2531 spin_lock(&sci->sc_state_lock); 2532 } 2533 finish_wait(&sci->sc_wait_daemon, &wait); 2534 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2535 time_after_eq(jiffies, sci->sc_timer.expires)); 2536 2537 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs)) 2538 set_nilfs_discontinued(nilfs); 2539 } 2540 goto loop; 2541 2542 end_thread: 2543 spin_unlock(&sci->sc_state_lock); 2544 2545 /* end sync. */ 2546 sci->sc_task = NULL; 2547 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */ 2548 return 0; 2549 } 2550 2551 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci) 2552 { 2553 struct task_struct *t; 2554 2555 t = kthread_run(nilfs_segctor_thread, sci, "segctord"); 2556 if (IS_ERR(t)) { 2557 int err = PTR_ERR(t); 2558 2559 printk(KERN_ERR "NILFS: error %d creating segctord thread\n", 2560 err); 2561 return err; 2562 } 2563 wait_event(sci->sc_wait_task, sci->sc_task != NULL); 2564 return 0; 2565 } 2566 2567 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci) 2568 __acquires(&sci->sc_state_lock) 2569 __releases(&sci->sc_state_lock) 2570 { 2571 sci->sc_state |= NILFS_SEGCTOR_QUIT; 2572 2573 while (sci->sc_task) { 2574 wake_up(&sci->sc_wait_daemon); 2575 spin_unlock(&sci->sc_state_lock); 2576 wait_event(sci->sc_wait_task, sci->sc_task == NULL); 2577 spin_lock(&sci->sc_state_lock); 2578 } 2579 } 2580 2581 /* 2582 * Setup & clean-up functions 2583 */ 2584 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb, 2585 struct nilfs_root *root) 2586 { 2587 struct the_nilfs *nilfs = sb->s_fs_info; 2588 struct nilfs_sc_info *sci; 2589 2590 sci = kzalloc(sizeof(*sci), GFP_KERNEL); 2591 if (!sci) 2592 return NULL; 2593 2594 sci->sc_super = sb; 2595 2596 nilfs_get_root(root); 2597 sci->sc_root = root; 2598 2599 init_waitqueue_head(&sci->sc_wait_request); 2600 init_waitqueue_head(&sci->sc_wait_daemon); 2601 init_waitqueue_head(&sci->sc_wait_task); 2602 spin_lock_init(&sci->sc_state_lock); 2603 INIT_LIST_HEAD(&sci->sc_dirty_files); 2604 INIT_LIST_HEAD(&sci->sc_segbufs); 2605 INIT_LIST_HEAD(&sci->sc_write_logs); 2606 INIT_LIST_HEAD(&sci->sc_gc_inodes); 2607 INIT_LIST_HEAD(&sci->sc_iput_queue); 2608 INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func); 2609 init_timer(&sci->sc_timer); 2610 2611 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT; 2612 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ; 2613 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK; 2614 2615 if (nilfs->ns_interval) 2616 sci->sc_interval = HZ * nilfs->ns_interval; 2617 if (nilfs->ns_watermark) 2618 sci->sc_watermark = nilfs->ns_watermark; 2619 return sci; 2620 } 2621 2622 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci) 2623 { 2624 int ret, retrycount = NILFS_SC_CLEANUP_RETRY; 2625 2626 /* The segctord thread was stopped and its timer was removed. 2627 But some tasks remain. */ 2628 do { 2629 struct nilfs_transaction_info ti; 2630 2631 nilfs_transaction_lock(sci->sc_super, &ti, 0); 2632 ret = nilfs_segctor_construct(sci, SC_LSEG_SR); 2633 nilfs_transaction_unlock(sci->sc_super); 2634 2635 flush_work(&sci->sc_iput_work); 2636 2637 } while (ret && retrycount-- > 0); 2638 } 2639 2640 /** 2641 * nilfs_segctor_destroy - destroy the segment constructor. 2642 * @sci: nilfs_sc_info 2643 * 2644 * nilfs_segctor_destroy() kills the segctord thread and frees 2645 * the nilfs_sc_info struct. 2646 * Caller must hold the segment semaphore. 2647 */ 2648 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci) 2649 { 2650 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2651 int flag; 2652 2653 up_write(&nilfs->ns_segctor_sem); 2654 2655 spin_lock(&sci->sc_state_lock); 2656 nilfs_segctor_kill_thread(sci); 2657 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request 2658 || sci->sc_seq_request != sci->sc_seq_done); 2659 spin_unlock(&sci->sc_state_lock); 2660 2661 if (flush_work(&sci->sc_iput_work)) 2662 flag = true; 2663 2664 if (flag || !nilfs_segctor_confirm(sci)) 2665 nilfs_segctor_write_out(sci); 2666 2667 if (!list_empty(&sci->sc_dirty_files)) { 2668 nilfs_warning(sci->sc_super, __func__, 2669 "dirty file(s) after the final construction\n"); 2670 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1); 2671 } 2672 2673 if (!list_empty(&sci->sc_iput_queue)) { 2674 nilfs_warning(sci->sc_super, __func__, 2675 "iput queue is not empty\n"); 2676 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1); 2677 } 2678 2679 WARN_ON(!list_empty(&sci->sc_segbufs)); 2680 WARN_ON(!list_empty(&sci->sc_write_logs)); 2681 2682 nilfs_put_root(sci->sc_root); 2683 2684 down_write(&nilfs->ns_segctor_sem); 2685 2686 del_timer_sync(&sci->sc_timer); 2687 kfree(sci); 2688 } 2689 2690 /** 2691 * nilfs_attach_log_writer - attach log writer 2692 * @sb: super block instance 2693 * @root: root object of the current filesystem tree 2694 * 2695 * This allocates a log writer object, initializes it, and starts the 2696 * log writer. 2697 * 2698 * Return Value: On success, 0 is returned. On error, one of the following 2699 * negative error code is returned. 2700 * 2701 * %-ENOMEM - Insufficient memory available. 2702 */ 2703 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root) 2704 { 2705 struct the_nilfs *nilfs = sb->s_fs_info; 2706 int err; 2707 2708 if (nilfs->ns_writer) { 2709 /* 2710 * This happens if the filesystem was remounted 2711 * read/write after nilfs_error degenerated it into a 2712 * read-only mount. 2713 */ 2714 nilfs_detach_log_writer(sb); 2715 } 2716 2717 nilfs->ns_writer = nilfs_segctor_new(sb, root); 2718 if (!nilfs->ns_writer) 2719 return -ENOMEM; 2720 2721 err = nilfs_segctor_start_thread(nilfs->ns_writer); 2722 if (err) { 2723 kfree(nilfs->ns_writer); 2724 nilfs->ns_writer = NULL; 2725 } 2726 return err; 2727 } 2728 2729 /** 2730 * nilfs_detach_log_writer - destroy log writer 2731 * @sb: super block instance 2732 * 2733 * This kills log writer daemon, frees the log writer object, and 2734 * destroys list of dirty files. 2735 */ 2736 void nilfs_detach_log_writer(struct super_block *sb) 2737 { 2738 struct the_nilfs *nilfs = sb->s_fs_info; 2739 LIST_HEAD(garbage_list); 2740 2741 down_write(&nilfs->ns_segctor_sem); 2742 if (nilfs->ns_writer) { 2743 nilfs_segctor_destroy(nilfs->ns_writer); 2744 nilfs->ns_writer = NULL; 2745 } 2746 2747 /* Force to free the list of dirty files */ 2748 spin_lock(&nilfs->ns_inode_lock); 2749 if (!list_empty(&nilfs->ns_dirty_files)) { 2750 list_splice_init(&nilfs->ns_dirty_files, &garbage_list); 2751 nilfs_warning(sb, __func__, 2752 "Hit dirty file after stopped log writer\n"); 2753 } 2754 spin_unlock(&nilfs->ns_inode_lock); 2755 up_write(&nilfs->ns_segctor_sem); 2756 2757 nilfs_dispose_list(nilfs, &garbage_list, 1); 2758 } 2759