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 sb_start_intwrite(sb); 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 sb_end_intwrite(sb); 209 return ret; 210 } 211 212 /** 213 * nilfs_transaction_commit - commit indivisible file operations. 214 * @sb: super block 215 * 216 * nilfs_transaction_commit() releases the read semaphore which is 217 * acquired by nilfs_transaction_begin(). This is only performed 218 * in outermost call of this function. If a commit flag is set, 219 * nilfs_transaction_commit() sets a timer to start the segment 220 * constructor. If a sync flag is set, it starts construction 221 * directly. 222 */ 223 int nilfs_transaction_commit(struct super_block *sb) 224 { 225 struct nilfs_transaction_info *ti = current->journal_info; 226 struct the_nilfs *nilfs = sb->s_fs_info; 227 int err = 0; 228 229 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 230 ti->ti_flags |= NILFS_TI_COMMIT; 231 if (ti->ti_count > 0) { 232 ti->ti_count--; 233 return 0; 234 } 235 if (nilfs->ns_writer) { 236 struct nilfs_sc_info *sci = nilfs->ns_writer; 237 238 if (ti->ti_flags & NILFS_TI_COMMIT) 239 nilfs_segctor_start_timer(sci); 240 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark) 241 nilfs_segctor_do_flush(sci, 0); 242 } 243 up_read(&nilfs->ns_segctor_sem); 244 current->journal_info = ti->ti_save; 245 246 if (ti->ti_flags & NILFS_TI_SYNC) 247 err = nilfs_construct_segment(sb); 248 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 249 kmem_cache_free(nilfs_transaction_cachep, ti); 250 sb_end_intwrite(sb); 251 return err; 252 } 253 254 void nilfs_transaction_abort(struct super_block *sb) 255 { 256 struct nilfs_transaction_info *ti = current->journal_info; 257 struct the_nilfs *nilfs = sb->s_fs_info; 258 259 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); 260 if (ti->ti_count > 0) { 261 ti->ti_count--; 262 return; 263 } 264 up_read(&nilfs->ns_segctor_sem); 265 266 current->journal_info = ti->ti_save; 267 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) 268 kmem_cache_free(nilfs_transaction_cachep, ti); 269 sb_end_intwrite(sb); 270 } 271 272 void nilfs_relax_pressure_in_lock(struct super_block *sb) 273 { 274 struct the_nilfs *nilfs = sb->s_fs_info; 275 struct nilfs_sc_info *sci = nilfs->ns_writer; 276 277 if (!sci || !sci->sc_flush_request) 278 return; 279 280 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 281 up_read(&nilfs->ns_segctor_sem); 282 283 down_write(&nilfs->ns_segctor_sem); 284 if (sci->sc_flush_request && 285 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) { 286 struct nilfs_transaction_info *ti = current->journal_info; 287 288 ti->ti_flags |= NILFS_TI_WRITER; 289 nilfs_segctor_do_immediate_flush(sci); 290 ti->ti_flags &= ~NILFS_TI_WRITER; 291 } 292 downgrade_write(&nilfs->ns_segctor_sem); 293 } 294 295 static void nilfs_transaction_lock(struct super_block *sb, 296 struct nilfs_transaction_info *ti, 297 int gcflag) 298 { 299 struct nilfs_transaction_info *cur_ti = current->journal_info; 300 struct the_nilfs *nilfs = sb->s_fs_info; 301 struct nilfs_sc_info *sci = nilfs->ns_writer; 302 303 WARN_ON(cur_ti); 304 ti->ti_flags = NILFS_TI_WRITER; 305 ti->ti_count = 0; 306 ti->ti_save = cur_ti; 307 ti->ti_magic = NILFS_TI_MAGIC; 308 INIT_LIST_HEAD(&ti->ti_garbage); 309 current->journal_info = ti; 310 311 for (;;) { 312 down_write(&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 if (!list_empty(&ti->ti_garbage)) 336 nilfs_dispose_list(nilfs, &ti->ti_garbage, 0); 337 } 338 339 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci, 340 struct nilfs_segsum_pointer *ssp, 341 unsigned bytes) 342 { 343 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 344 unsigned blocksize = sci->sc_super->s_blocksize; 345 void *p; 346 347 if (unlikely(ssp->offset + bytes > blocksize)) { 348 ssp->offset = 0; 349 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh, 350 &segbuf->sb_segsum_buffers)); 351 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh); 352 } 353 p = ssp->bh->b_data + ssp->offset; 354 ssp->offset += bytes; 355 return p; 356 } 357 358 /** 359 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer 360 * @sci: nilfs_sc_info 361 */ 362 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci) 363 { 364 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 365 struct buffer_head *sumbh; 366 unsigned sumbytes; 367 unsigned flags = 0; 368 int err; 369 370 if (nilfs_doing_gc()) 371 flags = NILFS_SS_GC; 372 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno); 373 if (unlikely(err)) 374 return err; 375 376 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); 377 sumbytes = segbuf->sb_sum.sumbytes; 378 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes; 379 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes; 380 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; 381 return 0; 382 } 383 384 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci) 385 { 386 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; 387 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs)) 388 return -E2BIG; /* The current segment is filled up 389 (internal code) */ 390 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg); 391 return nilfs_segctor_reset_segment_buffer(sci); 392 } 393 394 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci) 395 { 396 struct nilfs_segment_buffer *segbuf = sci->sc_curseg; 397 int err; 398 399 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) { 400 err = nilfs_segctor_feed_segment(sci); 401 if (err) 402 return err; 403 segbuf = sci->sc_curseg; 404 } 405 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root); 406 if (likely(!err)) 407 segbuf->sb_sum.flags |= NILFS_SS_SR; 408 return err; 409 } 410 411 /* 412 * Functions for making segment summary and payloads 413 */ 414 static int nilfs_segctor_segsum_block_required( 415 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp, 416 unsigned binfo_size) 417 { 418 unsigned blocksize = sci->sc_super->s_blocksize; 419 /* Size of finfo and binfo is enough small against blocksize */ 420 421 return ssp->offset + binfo_size + 422 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) > 423 blocksize; 424 } 425 426 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci, 427 struct inode *inode) 428 { 429 sci->sc_curseg->sb_sum.nfinfo++; 430 sci->sc_binfo_ptr = sci->sc_finfo_ptr; 431 nilfs_segctor_map_segsum_entry( 432 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo)); 433 434 if (NILFS_I(inode)->i_root && 435 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 436 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 437 /* skip finfo */ 438 } 439 440 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci, 441 struct inode *inode) 442 { 443 struct nilfs_finfo *finfo; 444 struct nilfs_inode_info *ii; 445 struct nilfs_segment_buffer *segbuf; 446 __u64 cno; 447 448 if (sci->sc_blk_cnt == 0) 449 return; 450 451 ii = NILFS_I(inode); 452 453 if (test_bit(NILFS_I_GCINODE, &ii->i_state)) 454 cno = ii->i_cno; 455 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) 456 cno = 0; 457 else 458 cno = sci->sc_cno; 459 460 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr, 461 sizeof(*finfo)); 462 finfo->fi_ino = cpu_to_le64(inode->i_ino); 463 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt); 464 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt); 465 finfo->fi_cno = cpu_to_le64(cno); 466 467 segbuf = sci->sc_curseg; 468 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset + 469 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1); 470 sci->sc_finfo_ptr = sci->sc_binfo_ptr; 471 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; 472 } 473 474 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci, 475 struct buffer_head *bh, 476 struct inode *inode, 477 unsigned binfo_size) 478 { 479 struct nilfs_segment_buffer *segbuf; 480 int required, err = 0; 481 482 retry: 483 segbuf = sci->sc_curseg; 484 required = nilfs_segctor_segsum_block_required( 485 sci, &sci->sc_binfo_ptr, binfo_size); 486 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) { 487 nilfs_segctor_end_finfo(sci, inode); 488 err = nilfs_segctor_feed_segment(sci); 489 if (err) 490 return err; 491 goto retry; 492 } 493 if (unlikely(required)) { 494 err = nilfs_segbuf_extend_segsum(segbuf); 495 if (unlikely(err)) 496 goto failed; 497 } 498 if (sci->sc_blk_cnt == 0) 499 nilfs_segctor_begin_finfo(sci, inode); 500 501 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size); 502 /* Substitution to vblocknr is delayed until update_blocknr() */ 503 nilfs_segbuf_add_file_buffer(segbuf, bh); 504 sci->sc_blk_cnt++; 505 failed: 506 return err; 507 } 508 509 /* 510 * Callback functions that enumerate, mark, and collect dirty blocks 511 */ 512 static int nilfs_collect_file_data(struct nilfs_sc_info *sci, 513 struct buffer_head *bh, struct inode *inode) 514 { 515 int err; 516 517 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 518 if (err < 0) 519 return err; 520 521 err = nilfs_segctor_add_file_block(sci, bh, inode, 522 sizeof(struct nilfs_binfo_v)); 523 if (!err) 524 sci->sc_datablk_cnt++; 525 return err; 526 } 527 528 static int nilfs_collect_file_node(struct nilfs_sc_info *sci, 529 struct buffer_head *bh, 530 struct inode *inode) 531 { 532 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 533 } 534 535 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci, 536 struct buffer_head *bh, 537 struct inode *inode) 538 { 539 WARN_ON(!buffer_dirty(bh)); 540 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); 541 } 542 543 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci, 544 struct nilfs_segsum_pointer *ssp, 545 union nilfs_binfo *binfo) 546 { 547 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry( 548 sci, ssp, sizeof(*binfo_v)); 549 *binfo_v = binfo->bi_v; 550 } 551 552 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci, 553 struct nilfs_segsum_pointer *ssp, 554 union nilfs_binfo *binfo) 555 { 556 __le64 *vblocknr = nilfs_segctor_map_segsum_entry( 557 sci, ssp, sizeof(*vblocknr)); 558 *vblocknr = binfo->bi_v.bi_vblocknr; 559 } 560 561 static struct nilfs_sc_operations nilfs_sc_file_ops = { 562 .collect_data = nilfs_collect_file_data, 563 .collect_node = nilfs_collect_file_node, 564 .collect_bmap = nilfs_collect_file_bmap, 565 .write_data_binfo = nilfs_write_file_data_binfo, 566 .write_node_binfo = nilfs_write_file_node_binfo, 567 }; 568 569 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci, 570 struct buffer_head *bh, struct inode *inode) 571 { 572 int err; 573 574 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); 575 if (err < 0) 576 return err; 577 578 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); 579 if (!err) 580 sci->sc_datablk_cnt++; 581 return err; 582 } 583 584 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci, 585 struct buffer_head *bh, struct inode *inode) 586 { 587 WARN_ON(!buffer_dirty(bh)); 588 return nilfs_segctor_add_file_block(sci, bh, inode, 589 sizeof(struct nilfs_binfo_dat)); 590 } 591 592 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci, 593 struct nilfs_segsum_pointer *ssp, 594 union nilfs_binfo *binfo) 595 { 596 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp, 597 sizeof(*blkoff)); 598 *blkoff = binfo->bi_dat.bi_blkoff; 599 } 600 601 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci, 602 struct nilfs_segsum_pointer *ssp, 603 union nilfs_binfo *binfo) 604 { 605 struct nilfs_binfo_dat *binfo_dat = 606 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat)); 607 *binfo_dat = binfo->bi_dat; 608 } 609 610 static struct nilfs_sc_operations nilfs_sc_dat_ops = { 611 .collect_data = nilfs_collect_dat_data, 612 .collect_node = nilfs_collect_file_node, 613 .collect_bmap = nilfs_collect_dat_bmap, 614 .write_data_binfo = nilfs_write_dat_data_binfo, 615 .write_node_binfo = nilfs_write_dat_node_binfo, 616 }; 617 618 static struct nilfs_sc_operations nilfs_sc_dsync_ops = { 619 .collect_data = nilfs_collect_file_data, 620 .collect_node = NULL, 621 .collect_bmap = NULL, 622 .write_data_binfo = nilfs_write_file_data_binfo, 623 .write_node_binfo = NULL, 624 }; 625 626 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode, 627 struct list_head *listp, 628 size_t nlimit, 629 loff_t start, loff_t end) 630 { 631 struct address_space *mapping = inode->i_mapping; 632 struct pagevec pvec; 633 pgoff_t index = 0, last = ULONG_MAX; 634 size_t ndirties = 0; 635 int i; 636 637 if (unlikely(start != 0 || end != LLONG_MAX)) { 638 /* 639 * A valid range is given for sync-ing data pages. The 640 * range is rounded to per-page; extra dirty buffers 641 * may be included if blocksize < pagesize. 642 */ 643 index = start >> PAGE_SHIFT; 644 last = end >> PAGE_SHIFT; 645 } 646 pagevec_init(&pvec, 0); 647 repeat: 648 if (unlikely(index > last) || 649 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 650 min_t(pgoff_t, last - index, 651 PAGEVEC_SIZE - 1) + 1)) 652 return ndirties; 653 654 for (i = 0; i < pagevec_count(&pvec); i++) { 655 struct buffer_head *bh, *head; 656 struct page *page = pvec.pages[i]; 657 658 if (unlikely(page->index > last)) 659 break; 660 661 lock_page(page); 662 if (!page_has_buffers(page)) 663 create_empty_buffers(page, 1 << inode->i_blkbits, 0); 664 unlock_page(page); 665 666 bh = head = page_buffers(page); 667 do { 668 if (!buffer_dirty(bh) || buffer_async_write(bh)) 669 continue; 670 get_bh(bh); 671 list_add_tail(&bh->b_assoc_buffers, listp); 672 ndirties++; 673 if (unlikely(ndirties >= nlimit)) { 674 pagevec_release(&pvec); 675 cond_resched(); 676 return ndirties; 677 } 678 } while (bh = bh->b_this_page, bh != head); 679 } 680 pagevec_release(&pvec); 681 cond_resched(); 682 goto repeat; 683 } 684 685 static void nilfs_lookup_dirty_node_buffers(struct inode *inode, 686 struct list_head *listp) 687 { 688 struct nilfs_inode_info *ii = NILFS_I(inode); 689 struct address_space *mapping = &ii->i_btnode_cache; 690 struct pagevec pvec; 691 struct buffer_head *bh, *head; 692 unsigned int i; 693 pgoff_t index = 0; 694 695 pagevec_init(&pvec, 0); 696 697 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, 698 PAGEVEC_SIZE)) { 699 for (i = 0; i < pagevec_count(&pvec); i++) { 700 bh = head = page_buffers(pvec.pages[i]); 701 do { 702 if (buffer_dirty(bh) && 703 !buffer_async_write(bh)) { 704 get_bh(bh); 705 list_add_tail(&bh->b_assoc_buffers, 706 listp); 707 } 708 bh = bh->b_this_page; 709 } while (bh != head); 710 } 711 pagevec_release(&pvec); 712 cond_resched(); 713 } 714 } 715 716 static void nilfs_dispose_list(struct the_nilfs *nilfs, 717 struct list_head *head, int force) 718 { 719 struct nilfs_inode_info *ii, *n; 720 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii; 721 unsigned nv = 0; 722 723 while (!list_empty(head)) { 724 spin_lock(&nilfs->ns_inode_lock); 725 list_for_each_entry_safe(ii, n, head, i_dirty) { 726 list_del_init(&ii->i_dirty); 727 if (force) { 728 if (unlikely(ii->i_bh)) { 729 brelse(ii->i_bh); 730 ii->i_bh = NULL; 731 } 732 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) { 733 set_bit(NILFS_I_QUEUED, &ii->i_state); 734 list_add_tail(&ii->i_dirty, 735 &nilfs->ns_dirty_files); 736 continue; 737 } 738 ivec[nv++] = ii; 739 if (nv == SC_N_INODEVEC) 740 break; 741 } 742 spin_unlock(&nilfs->ns_inode_lock); 743 744 for (pii = ivec; nv > 0; pii++, nv--) 745 iput(&(*pii)->vfs_inode); 746 } 747 } 748 749 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs, 750 struct nilfs_root *root) 751 { 752 int ret = 0; 753 754 if (nilfs_mdt_fetch_dirty(root->ifile)) 755 ret++; 756 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile)) 757 ret++; 758 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile)) 759 ret++; 760 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat)) 761 ret++; 762 return ret; 763 } 764 765 static int nilfs_segctor_clean(struct nilfs_sc_info *sci) 766 { 767 return list_empty(&sci->sc_dirty_files) && 768 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) && 769 sci->sc_nfreesegs == 0 && 770 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes)); 771 } 772 773 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci) 774 { 775 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 776 int ret = 0; 777 778 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 779 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 780 781 spin_lock(&nilfs->ns_inode_lock); 782 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci)) 783 ret++; 784 785 spin_unlock(&nilfs->ns_inode_lock); 786 return ret; 787 } 788 789 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci) 790 { 791 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 792 793 nilfs_mdt_clear_dirty(sci->sc_root->ifile); 794 nilfs_mdt_clear_dirty(nilfs->ns_cpfile); 795 nilfs_mdt_clear_dirty(nilfs->ns_sufile); 796 nilfs_mdt_clear_dirty(nilfs->ns_dat); 797 } 798 799 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci) 800 { 801 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 802 struct buffer_head *bh_cp; 803 struct nilfs_checkpoint *raw_cp; 804 int err; 805 806 /* XXX: this interface will be changed */ 807 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1, 808 &raw_cp, &bh_cp); 809 if (likely(!err)) { 810 /* The following code is duplicated with cpfile. But, it is 811 needed to collect the checkpoint even if it was not newly 812 created */ 813 mark_buffer_dirty(bh_cp); 814 nilfs_mdt_mark_dirty(nilfs->ns_cpfile); 815 nilfs_cpfile_put_checkpoint( 816 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 817 } else 818 WARN_ON(err == -EINVAL || err == -ENOENT); 819 820 return err; 821 } 822 823 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci) 824 { 825 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 826 struct buffer_head *bh_cp; 827 struct nilfs_checkpoint *raw_cp; 828 int err; 829 830 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0, 831 &raw_cp, &bh_cp); 832 if (unlikely(err)) { 833 WARN_ON(err == -EINVAL || err == -ENOENT); 834 goto failed_ibh; 835 } 836 raw_cp->cp_snapshot_list.ssl_next = 0; 837 raw_cp->cp_snapshot_list.ssl_prev = 0; 838 raw_cp->cp_inodes_count = 839 cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count)); 840 raw_cp->cp_blocks_count = 841 cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count)); 842 raw_cp->cp_nblk_inc = 843 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc); 844 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime); 845 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno); 846 847 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) 848 nilfs_checkpoint_clear_minor(raw_cp); 849 else 850 nilfs_checkpoint_set_minor(raw_cp); 851 852 nilfs_write_inode_common(sci->sc_root->ifile, 853 &raw_cp->cp_ifile_inode, 1); 854 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); 855 return 0; 856 857 failed_ibh: 858 return err; 859 } 860 861 static void nilfs_fill_in_file_bmap(struct inode *ifile, 862 struct nilfs_inode_info *ii) 863 864 { 865 struct buffer_head *ibh; 866 struct nilfs_inode *raw_inode; 867 868 if (test_bit(NILFS_I_BMAP, &ii->i_state)) { 869 ibh = ii->i_bh; 870 BUG_ON(!ibh); 871 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino, 872 ibh); 873 nilfs_bmap_write(ii->i_bmap, raw_inode); 874 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh); 875 } 876 } 877 878 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci) 879 { 880 struct nilfs_inode_info *ii; 881 882 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) { 883 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii); 884 set_bit(NILFS_I_COLLECTED, &ii->i_state); 885 } 886 } 887 888 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci, 889 struct the_nilfs *nilfs) 890 { 891 struct buffer_head *bh_sr; 892 struct nilfs_super_root *raw_sr; 893 unsigned isz, srsz; 894 895 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root; 896 raw_sr = (struct nilfs_super_root *)bh_sr->b_data; 897 isz = nilfs->ns_inode_size; 898 srsz = NILFS_SR_BYTES(isz); 899 900 raw_sr->sr_bytes = cpu_to_le16(srsz); 901 raw_sr->sr_nongc_ctime 902 = cpu_to_le64(nilfs_doing_gc() ? 903 nilfs->ns_nongc_ctime : sci->sc_seg_ctime); 904 raw_sr->sr_flags = 0; 905 906 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr + 907 NILFS_SR_DAT_OFFSET(isz), 1); 908 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr + 909 NILFS_SR_CPFILE_OFFSET(isz), 1); 910 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr + 911 NILFS_SR_SUFILE_OFFSET(isz), 1); 912 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz); 913 } 914 915 static void nilfs_redirty_inodes(struct list_head *head) 916 { 917 struct nilfs_inode_info *ii; 918 919 list_for_each_entry(ii, head, i_dirty) { 920 if (test_bit(NILFS_I_COLLECTED, &ii->i_state)) 921 clear_bit(NILFS_I_COLLECTED, &ii->i_state); 922 } 923 } 924 925 static void nilfs_drop_collected_inodes(struct list_head *head) 926 { 927 struct nilfs_inode_info *ii; 928 929 list_for_each_entry(ii, head, i_dirty) { 930 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state)) 931 continue; 932 933 clear_bit(NILFS_I_INODE_SYNC, &ii->i_state); 934 set_bit(NILFS_I_UPDATED, &ii->i_state); 935 } 936 } 937 938 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci, 939 struct inode *inode, 940 struct list_head *listp, 941 int (*collect)(struct nilfs_sc_info *, 942 struct buffer_head *, 943 struct inode *)) 944 { 945 struct buffer_head *bh, *n; 946 int err = 0; 947 948 if (collect) { 949 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) { 950 list_del_init(&bh->b_assoc_buffers); 951 err = collect(sci, bh, inode); 952 brelse(bh); 953 if (unlikely(err)) 954 goto dispose_buffers; 955 } 956 return 0; 957 } 958 959 dispose_buffers: 960 while (!list_empty(listp)) { 961 bh = list_first_entry(listp, struct buffer_head, 962 b_assoc_buffers); 963 list_del_init(&bh->b_assoc_buffers); 964 brelse(bh); 965 } 966 return err; 967 } 968 969 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci) 970 { 971 /* Remaining number of blocks within segment buffer */ 972 return sci->sc_segbuf_nblocks - 973 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks); 974 } 975 976 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci, 977 struct inode *inode, 978 struct nilfs_sc_operations *sc_ops) 979 { 980 LIST_HEAD(data_buffers); 981 LIST_HEAD(node_buffers); 982 int err; 983 984 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { 985 size_t n, rest = nilfs_segctor_buffer_rest(sci); 986 987 n = nilfs_lookup_dirty_data_buffers( 988 inode, &data_buffers, rest + 1, 0, LLONG_MAX); 989 if (n > rest) { 990 err = nilfs_segctor_apply_buffers( 991 sci, inode, &data_buffers, 992 sc_ops->collect_data); 993 BUG_ON(!err); /* always receive -E2BIG or true error */ 994 goto break_or_fail; 995 } 996 } 997 nilfs_lookup_dirty_node_buffers(inode, &node_buffers); 998 999 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { 1000 err = nilfs_segctor_apply_buffers( 1001 sci, inode, &data_buffers, sc_ops->collect_data); 1002 if (unlikely(err)) { 1003 /* dispose node list */ 1004 nilfs_segctor_apply_buffers( 1005 sci, inode, &node_buffers, NULL); 1006 goto break_or_fail; 1007 } 1008 sci->sc_stage.flags |= NILFS_CF_NODE; 1009 } 1010 /* Collect node */ 1011 err = nilfs_segctor_apply_buffers( 1012 sci, inode, &node_buffers, sc_ops->collect_node); 1013 if (unlikely(err)) 1014 goto break_or_fail; 1015 1016 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers); 1017 err = nilfs_segctor_apply_buffers( 1018 sci, inode, &node_buffers, sc_ops->collect_bmap); 1019 if (unlikely(err)) 1020 goto break_or_fail; 1021 1022 nilfs_segctor_end_finfo(sci, inode); 1023 sci->sc_stage.flags &= ~NILFS_CF_NODE; 1024 1025 break_or_fail: 1026 return err; 1027 } 1028 1029 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci, 1030 struct inode *inode) 1031 { 1032 LIST_HEAD(data_buffers); 1033 size_t n, rest = nilfs_segctor_buffer_rest(sci); 1034 int err; 1035 1036 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1, 1037 sci->sc_dsync_start, 1038 sci->sc_dsync_end); 1039 1040 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers, 1041 nilfs_collect_file_data); 1042 if (!err) { 1043 nilfs_segctor_end_finfo(sci, inode); 1044 BUG_ON(n > rest); 1045 /* always receive -E2BIG or true error if n > rest */ 1046 } 1047 return err; 1048 } 1049 1050 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode) 1051 { 1052 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1053 struct list_head *head; 1054 struct nilfs_inode_info *ii; 1055 size_t ndone; 1056 int err = 0; 1057 1058 switch (sci->sc_stage.scnt) { 1059 case NILFS_ST_INIT: 1060 /* Pre-processes */ 1061 sci->sc_stage.flags = 0; 1062 1063 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) { 1064 sci->sc_nblk_inc = 0; 1065 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN; 1066 if (mode == SC_LSEG_DSYNC) { 1067 sci->sc_stage.scnt = NILFS_ST_DSYNC; 1068 goto dsync_mode; 1069 } 1070 } 1071 1072 sci->sc_stage.dirty_file_ptr = NULL; 1073 sci->sc_stage.gc_inode_ptr = NULL; 1074 if (mode == SC_FLUSH_DAT) { 1075 sci->sc_stage.scnt = NILFS_ST_DAT; 1076 goto dat_stage; 1077 } 1078 sci->sc_stage.scnt++; /* Fall through */ 1079 case NILFS_ST_GC: 1080 if (nilfs_doing_gc()) { 1081 head = &sci->sc_gc_inodes; 1082 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr, 1083 head, i_dirty); 1084 list_for_each_entry_continue(ii, head, i_dirty) { 1085 err = nilfs_segctor_scan_file( 1086 sci, &ii->vfs_inode, 1087 &nilfs_sc_file_ops); 1088 if (unlikely(err)) { 1089 sci->sc_stage.gc_inode_ptr = list_entry( 1090 ii->i_dirty.prev, 1091 struct nilfs_inode_info, 1092 i_dirty); 1093 goto break_or_fail; 1094 } 1095 set_bit(NILFS_I_COLLECTED, &ii->i_state); 1096 } 1097 sci->sc_stage.gc_inode_ptr = NULL; 1098 } 1099 sci->sc_stage.scnt++; /* Fall through */ 1100 case NILFS_ST_FILE: 1101 head = &sci->sc_dirty_files; 1102 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head, 1103 i_dirty); 1104 list_for_each_entry_continue(ii, head, i_dirty) { 1105 clear_bit(NILFS_I_DIRTY, &ii->i_state); 1106 1107 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode, 1108 &nilfs_sc_file_ops); 1109 if (unlikely(err)) { 1110 sci->sc_stage.dirty_file_ptr = 1111 list_entry(ii->i_dirty.prev, 1112 struct nilfs_inode_info, 1113 i_dirty); 1114 goto break_or_fail; 1115 } 1116 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */ 1117 /* XXX: required ? */ 1118 } 1119 sci->sc_stage.dirty_file_ptr = NULL; 1120 if (mode == SC_FLUSH_FILE) { 1121 sci->sc_stage.scnt = NILFS_ST_DONE; 1122 return 0; 1123 } 1124 sci->sc_stage.scnt++; 1125 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED; 1126 /* Fall through */ 1127 case NILFS_ST_IFILE: 1128 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile, 1129 &nilfs_sc_file_ops); 1130 if (unlikely(err)) 1131 break; 1132 sci->sc_stage.scnt++; 1133 /* Creating a checkpoint */ 1134 err = nilfs_segctor_create_checkpoint(sci); 1135 if (unlikely(err)) 1136 break; 1137 /* Fall through */ 1138 case NILFS_ST_CPFILE: 1139 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile, 1140 &nilfs_sc_file_ops); 1141 if (unlikely(err)) 1142 break; 1143 sci->sc_stage.scnt++; /* Fall through */ 1144 case NILFS_ST_SUFILE: 1145 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs, 1146 sci->sc_nfreesegs, &ndone); 1147 if (unlikely(err)) { 1148 nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1149 sci->sc_freesegs, ndone, 1150 NULL); 1151 break; 1152 } 1153 sci->sc_stage.flags |= NILFS_CF_SUFREED; 1154 1155 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile, 1156 &nilfs_sc_file_ops); 1157 if (unlikely(err)) 1158 break; 1159 sci->sc_stage.scnt++; /* Fall through */ 1160 case NILFS_ST_DAT: 1161 dat_stage: 1162 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat, 1163 &nilfs_sc_dat_ops); 1164 if (unlikely(err)) 1165 break; 1166 if (mode == SC_FLUSH_DAT) { 1167 sci->sc_stage.scnt = NILFS_ST_DONE; 1168 return 0; 1169 } 1170 sci->sc_stage.scnt++; /* Fall through */ 1171 case NILFS_ST_SR: 1172 if (mode == SC_LSEG_SR) { 1173 /* Appending a super root */ 1174 err = nilfs_segctor_add_super_root(sci); 1175 if (unlikely(err)) 1176 break; 1177 } 1178 /* End of a logical segment */ 1179 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; 1180 sci->sc_stage.scnt = NILFS_ST_DONE; 1181 return 0; 1182 case NILFS_ST_DSYNC: 1183 dsync_mode: 1184 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT; 1185 ii = sci->sc_dsync_inode; 1186 if (!test_bit(NILFS_I_BUSY, &ii->i_state)) 1187 break; 1188 1189 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode); 1190 if (unlikely(err)) 1191 break; 1192 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; 1193 sci->sc_stage.scnt = NILFS_ST_DONE; 1194 return 0; 1195 case NILFS_ST_DONE: 1196 return 0; 1197 default: 1198 BUG(); 1199 } 1200 1201 break_or_fail: 1202 return err; 1203 } 1204 1205 /** 1206 * nilfs_segctor_begin_construction - setup segment buffer to make a new log 1207 * @sci: nilfs_sc_info 1208 * @nilfs: nilfs object 1209 */ 1210 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci, 1211 struct the_nilfs *nilfs) 1212 { 1213 struct nilfs_segment_buffer *segbuf, *prev; 1214 __u64 nextnum; 1215 int err, alloc = 0; 1216 1217 segbuf = nilfs_segbuf_new(sci->sc_super); 1218 if (unlikely(!segbuf)) 1219 return -ENOMEM; 1220 1221 if (list_empty(&sci->sc_write_logs)) { 1222 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 1223 nilfs->ns_pseg_offset, nilfs); 1224 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { 1225 nilfs_shift_to_next_segment(nilfs); 1226 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs); 1227 } 1228 1229 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq; 1230 nextnum = nilfs->ns_nextnum; 1231 1232 if (nilfs->ns_segnum == nilfs->ns_nextnum) 1233 /* Start from the head of a new full segment */ 1234 alloc++; 1235 } else { 1236 /* Continue logs */ 1237 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1238 nilfs_segbuf_map_cont(segbuf, prev); 1239 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq; 1240 nextnum = prev->sb_nextnum; 1241 1242 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { 1243 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); 1244 segbuf->sb_sum.seg_seq++; 1245 alloc++; 1246 } 1247 } 1248 1249 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum); 1250 if (err) 1251 goto failed; 1252 1253 if (alloc) { 1254 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum); 1255 if (err) 1256 goto failed; 1257 } 1258 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs); 1259 1260 BUG_ON(!list_empty(&sci->sc_segbufs)); 1261 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs); 1262 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks; 1263 return 0; 1264 1265 failed: 1266 nilfs_segbuf_free(segbuf); 1267 return err; 1268 } 1269 1270 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci, 1271 struct the_nilfs *nilfs, int nadd) 1272 { 1273 struct nilfs_segment_buffer *segbuf, *prev; 1274 struct inode *sufile = nilfs->ns_sufile; 1275 __u64 nextnextnum; 1276 LIST_HEAD(list); 1277 int err, ret, i; 1278 1279 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs); 1280 /* 1281 * Since the segment specified with nextnum might be allocated during 1282 * the previous construction, the buffer including its segusage may 1283 * not be dirty. The following call ensures that the buffer is dirty 1284 * and will pin the buffer on memory until the sufile is written. 1285 */ 1286 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum); 1287 if (unlikely(err)) 1288 return err; 1289 1290 for (i = 0; i < nadd; i++) { 1291 /* extend segment info */ 1292 err = -ENOMEM; 1293 segbuf = nilfs_segbuf_new(sci->sc_super); 1294 if (unlikely(!segbuf)) 1295 goto failed; 1296 1297 /* map this buffer to region of segment on-disk */ 1298 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); 1299 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks; 1300 1301 /* allocate the next next full segment */ 1302 err = nilfs_sufile_alloc(sufile, &nextnextnum); 1303 if (unlikely(err)) 1304 goto failed_segbuf; 1305 1306 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1; 1307 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs); 1308 1309 list_add_tail(&segbuf->sb_list, &list); 1310 prev = segbuf; 1311 } 1312 list_splice_tail(&list, &sci->sc_segbufs); 1313 return 0; 1314 1315 failed_segbuf: 1316 nilfs_segbuf_free(segbuf); 1317 failed: 1318 list_for_each_entry(segbuf, &list, sb_list) { 1319 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1320 WARN_ON(ret); /* never fails */ 1321 } 1322 nilfs_destroy_logs(&list); 1323 return err; 1324 } 1325 1326 static void nilfs_free_incomplete_logs(struct list_head *logs, 1327 struct the_nilfs *nilfs) 1328 { 1329 struct nilfs_segment_buffer *segbuf, *prev; 1330 struct inode *sufile = nilfs->ns_sufile; 1331 int ret; 1332 1333 segbuf = NILFS_FIRST_SEGBUF(logs); 1334 if (nilfs->ns_nextnum != segbuf->sb_nextnum) { 1335 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1336 WARN_ON(ret); /* never fails */ 1337 } 1338 if (atomic_read(&segbuf->sb_err)) { 1339 /* Case 1: The first segment failed */ 1340 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start) 1341 /* Case 1a: Partial segment appended into an existing 1342 segment */ 1343 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start, 1344 segbuf->sb_fseg_end); 1345 else /* Case 1b: New full segment */ 1346 set_nilfs_discontinued(nilfs); 1347 } 1348 1349 prev = segbuf; 1350 list_for_each_entry_continue(segbuf, logs, sb_list) { 1351 if (prev->sb_nextnum != segbuf->sb_nextnum) { 1352 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1353 WARN_ON(ret); /* never fails */ 1354 } 1355 if (atomic_read(&segbuf->sb_err) && 1356 segbuf->sb_segnum != nilfs->ns_nextnum) 1357 /* Case 2: extended segment (!= next) failed */ 1358 nilfs_sufile_set_error(sufile, segbuf->sb_segnum); 1359 prev = segbuf; 1360 } 1361 } 1362 1363 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci, 1364 struct inode *sufile) 1365 { 1366 struct nilfs_segment_buffer *segbuf; 1367 unsigned long live_blocks; 1368 int ret; 1369 1370 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1371 live_blocks = segbuf->sb_sum.nblocks + 1372 (segbuf->sb_pseg_start - segbuf->sb_fseg_start); 1373 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1374 live_blocks, 1375 sci->sc_seg_ctime); 1376 WARN_ON(ret); /* always succeed because the segusage is dirty */ 1377 } 1378 } 1379 1380 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile) 1381 { 1382 struct nilfs_segment_buffer *segbuf; 1383 int ret; 1384 1385 segbuf = NILFS_FIRST_SEGBUF(logs); 1386 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1387 segbuf->sb_pseg_start - 1388 segbuf->sb_fseg_start, 0); 1389 WARN_ON(ret); /* always succeed because the segusage is dirty */ 1390 1391 list_for_each_entry_continue(segbuf, logs, sb_list) { 1392 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, 1393 0, 0); 1394 WARN_ON(ret); /* always succeed */ 1395 } 1396 } 1397 1398 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci, 1399 struct nilfs_segment_buffer *last, 1400 struct inode *sufile) 1401 { 1402 struct nilfs_segment_buffer *segbuf = last; 1403 int ret; 1404 1405 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) { 1406 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks; 1407 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); 1408 WARN_ON(ret); 1409 } 1410 nilfs_truncate_logs(&sci->sc_segbufs, last); 1411 } 1412 1413 1414 static int nilfs_segctor_collect(struct nilfs_sc_info *sci, 1415 struct the_nilfs *nilfs, int mode) 1416 { 1417 struct nilfs_cstage prev_stage = sci->sc_stage; 1418 int err, nadd = 1; 1419 1420 /* Collection retry loop */ 1421 for (;;) { 1422 sci->sc_nblk_this_inc = 0; 1423 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs); 1424 1425 err = nilfs_segctor_reset_segment_buffer(sci); 1426 if (unlikely(err)) 1427 goto failed; 1428 1429 err = nilfs_segctor_collect_blocks(sci, mode); 1430 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; 1431 if (!err) 1432 break; 1433 1434 if (unlikely(err != -E2BIG)) 1435 goto failed; 1436 1437 /* The current segment is filled up */ 1438 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE) 1439 break; 1440 1441 nilfs_clear_logs(&sci->sc_segbufs); 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 sci->sc_stage.flags &= ~NILFS_CF_SUFREED; 1450 } 1451 1452 err = nilfs_segctor_extend_segments(sci, nilfs, nadd); 1453 if (unlikely(err)) 1454 return err; 1455 1456 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA); 1457 sci->sc_stage = prev_stage; 1458 } 1459 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile); 1460 return 0; 1461 1462 failed: 1463 return err; 1464 } 1465 1466 static void nilfs_list_replace_buffer(struct buffer_head *old_bh, 1467 struct buffer_head *new_bh) 1468 { 1469 BUG_ON(!list_empty(&new_bh->b_assoc_buffers)); 1470 1471 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers); 1472 /* The caller must release old_bh */ 1473 } 1474 1475 static int 1476 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci, 1477 struct nilfs_segment_buffer *segbuf, 1478 int mode) 1479 { 1480 struct inode *inode = NULL; 1481 sector_t blocknr; 1482 unsigned long nfinfo = segbuf->sb_sum.nfinfo; 1483 unsigned long nblocks = 0, ndatablk = 0; 1484 struct nilfs_sc_operations *sc_op = NULL; 1485 struct nilfs_segsum_pointer ssp; 1486 struct nilfs_finfo *finfo = NULL; 1487 union nilfs_binfo binfo; 1488 struct buffer_head *bh, *bh_org; 1489 ino_t ino = 0; 1490 int err = 0; 1491 1492 if (!nfinfo) 1493 goto out; 1494 1495 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk; 1496 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); 1497 ssp.offset = sizeof(struct nilfs_segment_summary); 1498 1499 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { 1500 if (bh == segbuf->sb_super_root) 1501 break; 1502 if (!finfo) { 1503 finfo = nilfs_segctor_map_segsum_entry( 1504 sci, &ssp, sizeof(*finfo)); 1505 ino = le64_to_cpu(finfo->fi_ino); 1506 nblocks = le32_to_cpu(finfo->fi_nblocks); 1507 ndatablk = le32_to_cpu(finfo->fi_ndatablk); 1508 1509 inode = bh->b_page->mapping->host; 1510 1511 if (mode == SC_LSEG_DSYNC) 1512 sc_op = &nilfs_sc_dsync_ops; 1513 else if (ino == NILFS_DAT_INO) 1514 sc_op = &nilfs_sc_dat_ops; 1515 else /* file blocks */ 1516 sc_op = &nilfs_sc_file_ops; 1517 } 1518 bh_org = bh; 1519 get_bh(bh_org); 1520 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr, 1521 &binfo); 1522 if (bh != bh_org) 1523 nilfs_list_replace_buffer(bh_org, bh); 1524 brelse(bh_org); 1525 if (unlikely(err)) 1526 goto failed_bmap; 1527 1528 if (ndatablk > 0) 1529 sc_op->write_data_binfo(sci, &ssp, &binfo); 1530 else 1531 sc_op->write_node_binfo(sci, &ssp, &binfo); 1532 1533 blocknr++; 1534 if (--nblocks == 0) { 1535 finfo = NULL; 1536 if (--nfinfo == 0) 1537 break; 1538 } else if (ndatablk > 0) 1539 ndatablk--; 1540 } 1541 out: 1542 return 0; 1543 1544 failed_bmap: 1545 return err; 1546 } 1547 1548 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode) 1549 { 1550 struct nilfs_segment_buffer *segbuf; 1551 int err; 1552 1553 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1554 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode); 1555 if (unlikely(err)) 1556 return err; 1557 nilfs_segbuf_fill_in_segsum(segbuf); 1558 } 1559 return 0; 1560 } 1561 1562 static void nilfs_begin_page_io(struct page *page) 1563 { 1564 if (!page || PageWriteback(page)) 1565 /* For split b-tree node pages, this function may be called 1566 twice. We ignore the 2nd or later calls by this check. */ 1567 return; 1568 1569 lock_page(page); 1570 clear_page_dirty_for_io(page); 1571 set_page_writeback(page); 1572 unlock_page(page); 1573 } 1574 1575 static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) 1576 { 1577 struct nilfs_segment_buffer *segbuf; 1578 struct page *bd_page = NULL, *fs_page = NULL; 1579 1580 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { 1581 struct buffer_head *bh; 1582 1583 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1584 b_assoc_buffers) { 1585 set_buffer_async_write(bh); 1586 if (bh->b_page != bd_page) { 1587 if (bd_page) { 1588 lock_page(bd_page); 1589 clear_page_dirty_for_io(bd_page); 1590 set_page_writeback(bd_page); 1591 unlock_page(bd_page); 1592 } 1593 bd_page = bh->b_page; 1594 } 1595 } 1596 1597 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1598 b_assoc_buffers) { 1599 set_buffer_async_write(bh); 1600 if (bh == segbuf->sb_super_root) { 1601 if (bh->b_page != bd_page) { 1602 lock_page(bd_page); 1603 clear_page_dirty_for_io(bd_page); 1604 set_page_writeback(bd_page); 1605 unlock_page(bd_page); 1606 bd_page = bh->b_page; 1607 } 1608 break; 1609 } 1610 if (bh->b_page != fs_page) { 1611 nilfs_begin_page_io(fs_page); 1612 fs_page = bh->b_page; 1613 } 1614 } 1615 } 1616 if (bd_page) { 1617 lock_page(bd_page); 1618 clear_page_dirty_for_io(bd_page); 1619 set_page_writeback(bd_page); 1620 unlock_page(bd_page); 1621 } 1622 nilfs_begin_page_io(fs_page); 1623 } 1624 1625 static int nilfs_segctor_write(struct nilfs_sc_info *sci, 1626 struct the_nilfs *nilfs) 1627 { 1628 int ret; 1629 1630 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs); 1631 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs); 1632 return ret; 1633 } 1634 1635 static void nilfs_end_page_io(struct page *page, int err) 1636 { 1637 if (!page) 1638 return; 1639 1640 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) { 1641 /* 1642 * For b-tree node pages, this function may be called twice 1643 * or more because they might be split in a segment. 1644 */ 1645 if (PageDirty(page)) { 1646 /* 1647 * For pages holding split b-tree node buffers, dirty 1648 * flag on the buffers may be cleared discretely. 1649 * In that case, the page is once redirtied for 1650 * remaining buffers, and it must be cancelled if 1651 * all the buffers get cleaned later. 1652 */ 1653 lock_page(page); 1654 if (nilfs_page_buffers_clean(page)) 1655 __nilfs_clear_page_dirty(page); 1656 unlock_page(page); 1657 } 1658 return; 1659 } 1660 1661 if (!err) { 1662 if (!nilfs_page_buffers_clean(page)) 1663 __set_page_dirty_nobuffers(page); 1664 ClearPageError(page); 1665 } else { 1666 __set_page_dirty_nobuffers(page); 1667 SetPageError(page); 1668 } 1669 1670 end_page_writeback(page); 1671 } 1672 1673 static void nilfs_abort_logs(struct list_head *logs, int err) 1674 { 1675 struct nilfs_segment_buffer *segbuf; 1676 struct page *bd_page = NULL, *fs_page = NULL; 1677 struct buffer_head *bh; 1678 1679 if (list_empty(logs)) 1680 return; 1681 1682 list_for_each_entry(segbuf, logs, sb_list) { 1683 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1684 b_assoc_buffers) { 1685 clear_buffer_async_write(bh); 1686 if (bh->b_page != bd_page) { 1687 if (bd_page) 1688 end_page_writeback(bd_page); 1689 bd_page = bh->b_page; 1690 } 1691 } 1692 1693 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1694 b_assoc_buffers) { 1695 clear_buffer_async_write(bh); 1696 if (bh == segbuf->sb_super_root) { 1697 if (bh->b_page != bd_page) { 1698 end_page_writeback(bd_page); 1699 bd_page = bh->b_page; 1700 } 1701 break; 1702 } 1703 if (bh->b_page != fs_page) { 1704 nilfs_end_page_io(fs_page, err); 1705 fs_page = bh->b_page; 1706 } 1707 } 1708 } 1709 if (bd_page) 1710 end_page_writeback(bd_page); 1711 1712 nilfs_end_page_io(fs_page, err); 1713 } 1714 1715 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci, 1716 struct the_nilfs *nilfs, int err) 1717 { 1718 LIST_HEAD(logs); 1719 int ret; 1720 1721 list_splice_tail_init(&sci->sc_write_logs, &logs); 1722 ret = nilfs_wait_on_logs(&logs); 1723 nilfs_abort_logs(&logs, ret ? : err); 1724 1725 list_splice_tail_init(&sci->sc_segbufs, &logs); 1726 nilfs_cancel_segusage(&logs, nilfs->ns_sufile); 1727 nilfs_free_incomplete_logs(&logs, nilfs); 1728 1729 if (sci->sc_stage.flags & NILFS_CF_SUFREED) { 1730 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile, 1731 sci->sc_freesegs, 1732 sci->sc_nfreesegs, 1733 NULL); 1734 WARN_ON(ret); /* do not happen */ 1735 } 1736 1737 nilfs_destroy_logs(&logs); 1738 } 1739 1740 static void nilfs_set_next_segment(struct the_nilfs *nilfs, 1741 struct nilfs_segment_buffer *segbuf) 1742 { 1743 nilfs->ns_segnum = segbuf->sb_segnum; 1744 nilfs->ns_nextnum = segbuf->sb_nextnum; 1745 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start 1746 + segbuf->sb_sum.nblocks; 1747 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq; 1748 nilfs->ns_ctime = segbuf->sb_sum.ctime; 1749 } 1750 1751 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) 1752 { 1753 struct nilfs_segment_buffer *segbuf; 1754 struct page *bd_page = NULL, *fs_page = NULL; 1755 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1756 int update_sr = false; 1757 1758 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) { 1759 struct buffer_head *bh; 1760 1761 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, 1762 b_assoc_buffers) { 1763 set_buffer_uptodate(bh); 1764 clear_buffer_dirty(bh); 1765 clear_buffer_async_write(bh); 1766 if (bh->b_page != bd_page) { 1767 if (bd_page) 1768 end_page_writeback(bd_page); 1769 bd_page = bh->b_page; 1770 } 1771 } 1772 /* 1773 * We assume that the buffers which belong to the same page 1774 * continue over the buffer list. 1775 * Under this assumption, the last BHs of pages is 1776 * identifiable by the discontinuity of bh->b_page 1777 * (page != fs_page). 1778 * 1779 * For B-tree node blocks, however, this assumption is not 1780 * guaranteed. The cleanup code of B-tree node pages needs 1781 * special care. 1782 */ 1783 list_for_each_entry(bh, &segbuf->sb_payload_buffers, 1784 b_assoc_buffers) { 1785 set_buffer_uptodate(bh); 1786 clear_buffer_dirty(bh); 1787 clear_buffer_async_write(bh); 1788 clear_buffer_delay(bh); 1789 clear_buffer_nilfs_volatile(bh); 1790 clear_buffer_nilfs_redirected(bh); 1791 if (bh == segbuf->sb_super_root) { 1792 if (bh->b_page != bd_page) { 1793 end_page_writeback(bd_page); 1794 bd_page = bh->b_page; 1795 } 1796 update_sr = true; 1797 break; 1798 } 1799 if (bh->b_page != fs_page) { 1800 nilfs_end_page_io(fs_page, 0); 1801 fs_page = bh->b_page; 1802 } 1803 } 1804 1805 if (!nilfs_segbuf_simplex(segbuf)) { 1806 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) { 1807 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1808 sci->sc_lseg_stime = jiffies; 1809 } 1810 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND) 1811 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); 1812 } 1813 } 1814 /* 1815 * Since pages may continue over multiple segment buffers, 1816 * end of the last page must be checked outside of the loop. 1817 */ 1818 if (bd_page) 1819 end_page_writeback(bd_page); 1820 1821 nilfs_end_page_io(fs_page, 0); 1822 1823 nilfs_drop_collected_inodes(&sci->sc_dirty_files); 1824 1825 if (nilfs_doing_gc()) 1826 nilfs_drop_collected_inodes(&sci->sc_gc_inodes); 1827 else 1828 nilfs->ns_nongc_ctime = sci->sc_seg_ctime; 1829 1830 sci->sc_nblk_inc += sci->sc_nblk_this_inc; 1831 1832 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs); 1833 nilfs_set_next_segment(nilfs, segbuf); 1834 1835 if (update_sr) { 1836 nilfs->ns_flushed_device = 0; 1837 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start, 1838 segbuf->sb_sum.seg_seq, nilfs->ns_cno++); 1839 1840 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); 1841 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags); 1842 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1843 nilfs_segctor_clear_metadata_dirty(sci); 1844 } else 1845 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); 1846 } 1847 1848 static int nilfs_segctor_wait(struct nilfs_sc_info *sci) 1849 { 1850 int ret; 1851 1852 ret = nilfs_wait_on_logs(&sci->sc_write_logs); 1853 if (!ret) { 1854 nilfs_segctor_complete_write(sci); 1855 nilfs_destroy_logs(&sci->sc_write_logs); 1856 } 1857 return ret; 1858 } 1859 1860 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci, 1861 struct the_nilfs *nilfs) 1862 { 1863 struct nilfs_inode_info *ii, *n; 1864 struct inode *ifile = sci->sc_root->ifile; 1865 1866 spin_lock(&nilfs->ns_inode_lock); 1867 retry: 1868 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) { 1869 if (!ii->i_bh) { 1870 struct buffer_head *ibh; 1871 int err; 1872 1873 spin_unlock(&nilfs->ns_inode_lock); 1874 err = nilfs_ifile_get_inode_block( 1875 ifile, ii->vfs_inode.i_ino, &ibh); 1876 if (unlikely(err)) { 1877 nilfs_warning(sci->sc_super, __func__, 1878 "failed to get inode block.\n"); 1879 return err; 1880 } 1881 mark_buffer_dirty(ibh); 1882 nilfs_mdt_mark_dirty(ifile); 1883 spin_lock(&nilfs->ns_inode_lock); 1884 if (likely(!ii->i_bh)) 1885 ii->i_bh = ibh; 1886 else 1887 brelse(ibh); 1888 goto retry; 1889 } 1890 1891 clear_bit(NILFS_I_QUEUED, &ii->i_state); 1892 set_bit(NILFS_I_BUSY, &ii->i_state); 1893 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files); 1894 } 1895 spin_unlock(&nilfs->ns_inode_lock); 1896 1897 return 0; 1898 } 1899 1900 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci, 1901 struct the_nilfs *nilfs) 1902 { 1903 struct nilfs_transaction_info *ti = current->journal_info; 1904 struct nilfs_inode_info *ii, *n; 1905 1906 spin_lock(&nilfs->ns_inode_lock); 1907 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) { 1908 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) || 1909 test_bit(NILFS_I_DIRTY, &ii->i_state)) 1910 continue; 1911 1912 clear_bit(NILFS_I_BUSY, &ii->i_state); 1913 brelse(ii->i_bh); 1914 ii->i_bh = NULL; 1915 list_move_tail(&ii->i_dirty, &ti->ti_garbage); 1916 } 1917 spin_unlock(&nilfs->ns_inode_lock); 1918 } 1919 1920 /* 1921 * Main procedure of segment constructor 1922 */ 1923 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) 1924 { 1925 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 1926 int err; 1927 1928 sci->sc_stage.scnt = NILFS_ST_INIT; 1929 sci->sc_cno = nilfs->ns_cno; 1930 1931 err = nilfs_segctor_collect_dirty_files(sci, nilfs); 1932 if (unlikely(err)) 1933 goto out; 1934 1935 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) 1936 set_bit(NILFS_SC_DIRTY, &sci->sc_flags); 1937 1938 if (nilfs_segctor_clean(sci)) 1939 goto out; 1940 1941 do { 1942 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK; 1943 1944 err = nilfs_segctor_begin_construction(sci, nilfs); 1945 if (unlikely(err)) 1946 goto out; 1947 1948 /* Update time stamp */ 1949 sci->sc_seg_ctime = get_seconds(); 1950 1951 err = nilfs_segctor_collect(sci, nilfs, mode); 1952 if (unlikely(err)) 1953 goto failed; 1954 1955 /* Avoid empty segment */ 1956 if (sci->sc_stage.scnt == NILFS_ST_DONE && 1957 nilfs_segbuf_empty(sci->sc_curseg)) { 1958 nilfs_segctor_abort_construction(sci, nilfs, 1); 1959 goto out; 1960 } 1961 1962 err = nilfs_segctor_assign(sci, mode); 1963 if (unlikely(err)) 1964 goto failed; 1965 1966 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 1967 nilfs_segctor_fill_in_file_bmap(sci); 1968 1969 if (mode == SC_LSEG_SR && 1970 sci->sc_stage.scnt >= NILFS_ST_CPFILE) { 1971 err = nilfs_segctor_fill_in_checkpoint(sci); 1972 if (unlikely(err)) 1973 goto failed_to_write; 1974 1975 nilfs_segctor_fill_in_super_root(sci, nilfs); 1976 } 1977 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile); 1978 1979 /* Write partial segments */ 1980 nilfs_segctor_prepare_write(sci); 1981 1982 nilfs_add_checksums_on_logs(&sci->sc_segbufs, 1983 nilfs->ns_crc_seed); 1984 1985 err = nilfs_segctor_write(sci, nilfs); 1986 if (unlikely(err)) 1987 goto failed_to_write; 1988 1989 if (sci->sc_stage.scnt == NILFS_ST_DONE || 1990 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) { 1991 /* 1992 * At this point, we avoid double buffering 1993 * for blocksize < pagesize because page dirty 1994 * flag is turned off during write and dirty 1995 * buffers are not properly collected for 1996 * pages crossing over segments. 1997 */ 1998 err = nilfs_segctor_wait(sci); 1999 if (err) 2000 goto failed_to_write; 2001 } 2002 } while (sci->sc_stage.scnt != NILFS_ST_DONE); 2003 2004 out: 2005 nilfs_segctor_drop_written_files(sci, nilfs); 2006 return err; 2007 2008 failed_to_write: 2009 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) 2010 nilfs_redirty_inodes(&sci->sc_dirty_files); 2011 2012 failed: 2013 if (nilfs_doing_gc()) 2014 nilfs_redirty_inodes(&sci->sc_gc_inodes); 2015 nilfs_segctor_abort_construction(sci, nilfs, err); 2016 goto out; 2017 } 2018 2019 /** 2020 * nilfs_segctor_start_timer - set timer of background write 2021 * @sci: nilfs_sc_info 2022 * 2023 * If the timer has already been set, it ignores the new request. 2024 * This function MUST be called within a section locking the segment 2025 * semaphore. 2026 */ 2027 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci) 2028 { 2029 spin_lock(&sci->sc_state_lock); 2030 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) { 2031 sci->sc_timer.expires = jiffies + sci->sc_interval; 2032 add_timer(&sci->sc_timer); 2033 sci->sc_state |= NILFS_SEGCTOR_COMMIT; 2034 } 2035 spin_unlock(&sci->sc_state_lock); 2036 } 2037 2038 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn) 2039 { 2040 spin_lock(&sci->sc_state_lock); 2041 if (!(sci->sc_flush_request & (1 << bn))) { 2042 unsigned long prev_req = sci->sc_flush_request; 2043 2044 sci->sc_flush_request |= (1 << bn); 2045 if (!prev_req) 2046 wake_up(&sci->sc_wait_daemon); 2047 } 2048 spin_unlock(&sci->sc_state_lock); 2049 } 2050 2051 /** 2052 * nilfs_flush_segment - trigger a segment construction for resource control 2053 * @sb: super block 2054 * @ino: inode number of the file to be flushed out. 2055 */ 2056 void nilfs_flush_segment(struct super_block *sb, ino_t ino) 2057 { 2058 struct the_nilfs *nilfs = sb->s_fs_info; 2059 struct nilfs_sc_info *sci = nilfs->ns_writer; 2060 2061 if (!sci || nilfs_doing_construction()) 2062 return; 2063 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0); 2064 /* assign bit 0 to data files */ 2065 } 2066 2067 struct nilfs_segctor_wait_request { 2068 wait_queue_t wq; 2069 __u32 seq; 2070 int err; 2071 atomic_t done; 2072 }; 2073 2074 static int nilfs_segctor_sync(struct nilfs_sc_info *sci) 2075 { 2076 struct nilfs_segctor_wait_request wait_req; 2077 int err = 0; 2078 2079 spin_lock(&sci->sc_state_lock); 2080 init_wait(&wait_req.wq); 2081 wait_req.err = 0; 2082 atomic_set(&wait_req.done, 0); 2083 wait_req.seq = ++sci->sc_seq_request; 2084 spin_unlock(&sci->sc_state_lock); 2085 2086 init_waitqueue_entry(&wait_req.wq, current); 2087 add_wait_queue(&sci->sc_wait_request, &wait_req.wq); 2088 set_current_state(TASK_INTERRUPTIBLE); 2089 wake_up(&sci->sc_wait_daemon); 2090 2091 for (;;) { 2092 if (atomic_read(&wait_req.done)) { 2093 err = wait_req.err; 2094 break; 2095 } 2096 if (!signal_pending(current)) { 2097 schedule(); 2098 continue; 2099 } 2100 err = -ERESTARTSYS; 2101 break; 2102 } 2103 finish_wait(&sci->sc_wait_request, &wait_req.wq); 2104 return err; 2105 } 2106 2107 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err) 2108 { 2109 struct nilfs_segctor_wait_request *wrq, *n; 2110 unsigned long flags; 2111 2112 spin_lock_irqsave(&sci->sc_wait_request.lock, flags); 2113 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list, 2114 wq.task_list) { 2115 if (!atomic_read(&wrq->done) && 2116 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) { 2117 wrq->err = err; 2118 atomic_set(&wrq->done, 1); 2119 } 2120 if (atomic_read(&wrq->done)) { 2121 wrq->wq.func(&wrq->wq, 2122 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 2123 0, NULL); 2124 } 2125 } 2126 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags); 2127 } 2128 2129 /** 2130 * nilfs_construct_segment - construct a logical segment 2131 * @sb: super block 2132 * 2133 * Return Value: On success, 0 is retured. On errors, one of the following 2134 * negative error code is returned. 2135 * 2136 * %-EROFS - Read only filesystem. 2137 * 2138 * %-EIO - I/O error 2139 * 2140 * %-ENOSPC - No space left on device (only in a panic state). 2141 * 2142 * %-ERESTARTSYS - Interrupted. 2143 * 2144 * %-ENOMEM - Insufficient memory available. 2145 */ 2146 int nilfs_construct_segment(struct super_block *sb) 2147 { 2148 struct the_nilfs *nilfs = sb->s_fs_info; 2149 struct nilfs_sc_info *sci = nilfs->ns_writer; 2150 struct nilfs_transaction_info *ti; 2151 int err; 2152 2153 if (!sci) 2154 return -EROFS; 2155 2156 /* A call inside transactions causes a deadlock. */ 2157 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC); 2158 2159 err = nilfs_segctor_sync(sci); 2160 return err; 2161 } 2162 2163 /** 2164 * nilfs_construct_dsync_segment - construct a data-only logical segment 2165 * @sb: super block 2166 * @inode: inode whose data blocks should be written out 2167 * @start: start byte offset 2168 * @end: end byte offset (inclusive) 2169 * 2170 * Return Value: On success, 0 is retured. On errors, one of the following 2171 * negative error code is returned. 2172 * 2173 * %-EROFS - Read only filesystem. 2174 * 2175 * %-EIO - I/O error 2176 * 2177 * %-ENOSPC - No space left on device (only in a panic state). 2178 * 2179 * %-ERESTARTSYS - Interrupted. 2180 * 2181 * %-ENOMEM - Insufficient memory available. 2182 */ 2183 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode, 2184 loff_t start, loff_t end) 2185 { 2186 struct the_nilfs *nilfs = sb->s_fs_info; 2187 struct nilfs_sc_info *sci = nilfs->ns_writer; 2188 struct nilfs_inode_info *ii; 2189 struct nilfs_transaction_info ti; 2190 int err = 0; 2191 2192 if (!sci) 2193 return -EROFS; 2194 2195 nilfs_transaction_lock(sb, &ti, 0); 2196 2197 ii = NILFS_I(inode); 2198 if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) || 2199 nilfs_test_opt(nilfs, STRICT_ORDER) || 2200 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2201 nilfs_discontinued(nilfs)) { 2202 nilfs_transaction_unlock(sb); 2203 err = nilfs_segctor_sync(sci); 2204 return err; 2205 } 2206 2207 spin_lock(&nilfs->ns_inode_lock); 2208 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) && 2209 !test_bit(NILFS_I_BUSY, &ii->i_state)) { 2210 spin_unlock(&nilfs->ns_inode_lock); 2211 nilfs_transaction_unlock(sb); 2212 return 0; 2213 } 2214 spin_unlock(&nilfs->ns_inode_lock); 2215 sci->sc_dsync_inode = ii; 2216 sci->sc_dsync_start = start; 2217 sci->sc_dsync_end = end; 2218 2219 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC); 2220 if (!err) 2221 nilfs->ns_flushed_device = 0; 2222 2223 nilfs_transaction_unlock(sb); 2224 return err; 2225 } 2226 2227 #define FLUSH_FILE_BIT (0x1) /* data file only */ 2228 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */ 2229 2230 /** 2231 * nilfs_segctor_accept - record accepted sequence count of log-write requests 2232 * @sci: segment constructor object 2233 */ 2234 static void nilfs_segctor_accept(struct nilfs_sc_info *sci) 2235 { 2236 spin_lock(&sci->sc_state_lock); 2237 sci->sc_seq_accepted = sci->sc_seq_request; 2238 spin_unlock(&sci->sc_state_lock); 2239 del_timer_sync(&sci->sc_timer); 2240 } 2241 2242 /** 2243 * nilfs_segctor_notify - notify the result of request to caller threads 2244 * @sci: segment constructor object 2245 * @mode: mode of log forming 2246 * @err: error code to be notified 2247 */ 2248 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err) 2249 { 2250 /* Clear requests (even when the construction failed) */ 2251 spin_lock(&sci->sc_state_lock); 2252 2253 if (mode == SC_LSEG_SR) { 2254 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT; 2255 sci->sc_seq_done = sci->sc_seq_accepted; 2256 nilfs_segctor_wakeup(sci, err); 2257 sci->sc_flush_request = 0; 2258 } else { 2259 if (mode == SC_FLUSH_FILE) 2260 sci->sc_flush_request &= ~FLUSH_FILE_BIT; 2261 else if (mode == SC_FLUSH_DAT) 2262 sci->sc_flush_request &= ~FLUSH_DAT_BIT; 2263 2264 /* re-enable timer if checkpoint creation was not done */ 2265 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2266 time_before(jiffies, sci->sc_timer.expires)) 2267 add_timer(&sci->sc_timer); 2268 } 2269 spin_unlock(&sci->sc_state_lock); 2270 } 2271 2272 /** 2273 * nilfs_segctor_construct - form logs and write them to disk 2274 * @sci: segment constructor object 2275 * @mode: mode of log forming 2276 */ 2277 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode) 2278 { 2279 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2280 struct nilfs_super_block **sbp; 2281 int err = 0; 2282 2283 nilfs_segctor_accept(sci); 2284 2285 if (nilfs_discontinued(nilfs)) 2286 mode = SC_LSEG_SR; 2287 if (!nilfs_segctor_confirm(sci)) 2288 err = nilfs_segctor_do_construct(sci, mode); 2289 2290 if (likely(!err)) { 2291 if (mode != SC_FLUSH_DAT) 2292 atomic_set(&nilfs->ns_ndirtyblks, 0); 2293 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) && 2294 nilfs_discontinued(nilfs)) { 2295 down_write(&nilfs->ns_sem); 2296 err = -EIO; 2297 sbp = nilfs_prepare_super(sci->sc_super, 2298 nilfs_sb_will_flip(nilfs)); 2299 if (likely(sbp)) { 2300 nilfs_set_log_cursor(sbp[0], nilfs); 2301 err = nilfs_commit_super(sci->sc_super, 2302 NILFS_SB_COMMIT); 2303 } 2304 up_write(&nilfs->ns_sem); 2305 } 2306 } 2307 2308 nilfs_segctor_notify(sci, mode, err); 2309 return err; 2310 } 2311 2312 static void nilfs_construction_timeout(unsigned long data) 2313 { 2314 struct task_struct *p = (struct task_struct *)data; 2315 wake_up_process(p); 2316 } 2317 2318 static void 2319 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head) 2320 { 2321 struct nilfs_inode_info *ii, *n; 2322 2323 list_for_each_entry_safe(ii, n, head, i_dirty) { 2324 if (!test_bit(NILFS_I_UPDATED, &ii->i_state)) 2325 continue; 2326 list_del_init(&ii->i_dirty); 2327 truncate_inode_pages(&ii->vfs_inode.i_data, 0); 2328 nilfs_btnode_cache_clear(&ii->i_btnode_cache); 2329 iput(&ii->vfs_inode); 2330 } 2331 } 2332 2333 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv, 2334 void **kbufs) 2335 { 2336 struct the_nilfs *nilfs = sb->s_fs_info; 2337 struct nilfs_sc_info *sci = nilfs->ns_writer; 2338 struct nilfs_transaction_info ti; 2339 int err; 2340 2341 if (unlikely(!sci)) 2342 return -EROFS; 2343 2344 nilfs_transaction_lock(sb, &ti, 1); 2345 2346 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat); 2347 if (unlikely(err)) 2348 goto out_unlock; 2349 2350 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs); 2351 if (unlikely(err)) { 2352 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat); 2353 goto out_unlock; 2354 } 2355 2356 sci->sc_freesegs = kbufs[4]; 2357 sci->sc_nfreesegs = argv[4].v_nmembs; 2358 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes); 2359 2360 for (;;) { 2361 err = nilfs_segctor_construct(sci, SC_LSEG_SR); 2362 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes); 2363 2364 if (likely(!err)) 2365 break; 2366 2367 nilfs_warning(sb, __func__, 2368 "segment construction failed. (err=%d)", err); 2369 set_current_state(TASK_INTERRUPTIBLE); 2370 schedule_timeout(sci->sc_interval); 2371 } 2372 if (nilfs_test_opt(nilfs, DISCARD)) { 2373 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs, 2374 sci->sc_nfreesegs); 2375 if (ret) { 2376 printk(KERN_WARNING 2377 "NILFS warning: error %d on discard request, " 2378 "turning discards off for the device\n", ret); 2379 nilfs_clear_opt(nilfs, DISCARD); 2380 } 2381 } 2382 2383 out_unlock: 2384 sci->sc_freesegs = NULL; 2385 sci->sc_nfreesegs = 0; 2386 nilfs_mdt_clear_shadow_map(nilfs->ns_dat); 2387 nilfs_transaction_unlock(sb); 2388 return err; 2389 } 2390 2391 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode) 2392 { 2393 struct nilfs_transaction_info ti; 2394 2395 nilfs_transaction_lock(sci->sc_super, &ti, 0); 2396 nilfs_segctor_construct(sci, mode); 2397 2398 /* 2399 * Unclosed segment should be retried. We do this using sc_timer. 2400 * Timeout of sc_timer will invoke complete construction which leads 2401 * to close the current logical segment. 2402 */ 2403 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) 2404 nilfs_segctor_start_timer(sci); 2405 2406 nilfs_transaction_unlock(sci->sc_super); 2407 } 2408 2409 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci) 2410 { 2411 int mode = 0; 2412 int err; 2413 2414 spin_lock(&sci->sc_state_lock); 2415 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ? 2416 SC_FLUSH_DAT : SC_FLUSH_FILE; 2417 spin_unlock(&sci->sc_state_lock); 2418 2419 if (mode) { 2420 err = nilfs_segctor_do_construct(sci, mode); 2421 2422 spin_lock(&sci->sc_state_lock); 2423 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ? 2424 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT; 2425 spin_unlock(&sci->sc_state_lock); 2426 } 2427 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); 2428 } 2429 2430 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci) 2431 { 2432 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || 2433 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) { 2434 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT)) 2435 return SC_FLUSH_FILE; 2436 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT)) 2437 return SC_FLUSH_DAT; 2438 } 2439 return SC_LSEG_SR; 2440 } 2441 2442 /** 2443 * nilfs_segctor_thread - main loop of the segment constructor thread. 2444 * @arg: pointer to a struct nilfs_sc_info. 2445 * 2446 * nilfs_segctor_thread() initializes a timer and serves as a daemon 2447 * to execute segment constructions. 2448 */ 2449 static int nilfs_segctor_thread(void *arg) 2450 { 2451 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg; 2452 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2453 int timeout = 0; 2454 2455 sci->sc_timer.data = (unsigned long)current; 2456 sci->sc_timer.function = nilfs_construction_timeout; 2457 2458 /* start sync. */ 2459 sci->sc_task = current; 2460 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */ 2461 printk(KERN_INFO 2462 "segctord starting. Construction interval = %lu seconds, " 2463 "CP frequency < %lu seconds\n", 2464 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ); 2465 2466 spin_lock(&sci->sc_state_lock); 2467 loop: 2468 for (;;) { 2469 int mode; 2470 2471 if (sci->sc_state & NILFS_SEGCTOR_QUIT) 2472 goto end_thread; 2473 2474 if (timeout || sci->sc_seq_request != sci->sc_seq_done) 2475 mode = SC_LSEG_SR; 2476 else if (!sci->sc_flush_request) 2477 break; 2478 else 2479 mode = nilfs_segctor_flush_mode(sci); 2480 2481 spin_unlock(&sci->sc_state_lock); 2482 nilfs_segctor_thread_construct(sci, mode); 2483 spin_lock(&sci->sc_state_lock); 2484 timeout = 0; 2485 } 2486 2487 2488 if (freezing(current)) { 2489 spin_unlock(&sci->sc_state_lock); 2490 try_to_freeze(); 2491 spin_lock(&sci->sc_state_lock); 2492 } else { 2493 DEFINE_WAIT(wait); 2494 int should_sleep = 1; 2495 2496 prepare_to_wait(&sci->sc_wait_daemon, &wait, 2497 TASK_INTERRUPTIBLE); 2498 2499 if (sci->sc_seq_request != sci->sc_seq_done) 2500 should_sleep = 0; 2501 else if (sci->sc_flush_request) 2502 should_sleep = 0; 2503 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT) 2504 should_sleep = time_before(jiffies, 2505 sci->sc_timer.expires); 2506 2507 if (should_sleep) { 2508 spin_unlock(&sci->sc_state_lock); 2509 schedule(); 2510 spin_lock(&sci->sc_state_lock); 2511 } 2512 finish_wait(&sci->sc_wait_daemon, &wait); 2513 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && 2514 time_after_eq(jiffies, sci->sc_timer.expires)); 2515 2516 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs)) 2517 set_nilfs_discontinued(nilfs); 2518 } 2519 goto loop; 2520 2521 end_thread: 2522 spin_unlock(&sci->sc_state_lock); 2523 2524 /* end sync. */ 2525 sci->sc_task = NULL; 2526 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */ 2527 return 0; 2528 } 2529 2530 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci) 2531 { 2532 struct task_struct *t; 2533 2534 t = kthread_run(nilfs_segctor_thread, sci, "segctord"); 2535 if (IS_ERR(t)) { 2536 int err = PTR_ERR(t); 2537 2538 printk(KERN_ERR "NILFS: error %d creating segctord thread\n", 2539 err); 2540 return err; 2541 } 2542 wait_event(sci->sc_wait_task, sci->sc_task != NULL); 2543 return 0; 2544 } 2545 2546 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci) 2547 __acquires(&sci->sc_state_lock) 2548 __releases(&sci->sc_state_lock) 2549 { 2550 sci->sc_state |= NILFS_SEGCTOR_QUIT; 2551 2552 while (sci->sc_task) { 2553 wake_up(&sci->sc_wait_daemon); 2554 spin_unlock(&sci->sc_state_lock); 2555 wait_event(sci->sc_wait_task, sci->sc_task == NULL); 2556 spin_lock(&sci->sc_state_lock); 2557 } 2558 } 2559 2560 /* 2561 * Setup & clean-up functions 2562 */ 2563 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb, 2564 struct nilfs_root *root) 2565 { 2566 struct the_nilfs *nilfs = sb->s_fs_info; 2567 struct nilfs_sc_info *sci; 2568 2569 sci = kzalloc(sizeof(*sci), GFP_KERNEL); 2570 if (!sci) 2571 return NULL; 2572 2573 sci->sc_super = sb; 2574 2575 nilfs_get_root(root); 2576 sci->sc_root = root; 2577 2578 init_waitqueue_head(&sci->sc_wait_request); 2579 init_waitqueue_head(&sci->sc_wait_daemon); 2580 init_waitqueue_head(&sci->sc_wait_task); 2581 spin_lock_init(&sci->sc_state_lock); 2582 INIT_LIST_HEAD(&sci->sc_dirty_files); 2583 INIT_LIST_HEAD(&sci->sc_segbufs); 2584 INIT_LIST_HEAD(&sci->sc_write_logs); 2585 INIT_LIST_HEAD(&sci->sc_gc_inodes); 2586 init_timer(&sci->sc_timer); 2587 2588 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT; 2589 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ; 2590 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK; 2591 2592 if (nilfs->ns_interval) 2593 sci->sc_interval = HZ * nilfs->ns_interval; 2594 if (nilfs->ns_watermark) 2595 sci->sc_watermark = nilfs->ns_watermark; 2596 return sci; 2597 } 2598 2599 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci) 2600 { 2601 int ret, retrycount = NILFS_SC_CLEANUP_RETRY; 2602 2603 /* The segctord thread was stopped and its timer was removed. 2604 But some tasks remain. */ 2605 do { 2606 struct nilfs_transaction_info ti; 2607 2608 nilfs_transaction_lock(sci->sc_super, &ti, 0); 2609 ret = nilfs_segctor_construct(sci, SC_LSEG_SR); 2610 nilfs_transaction_unlock(sci->sc_super); 2611 2612 } while (ret && retrycount-- > 0); 2613 } 2614 2615 /** 2616 * nilfs_segctor_destroy - destroy the segment constructor. 2617 * @sci: nilfs_sc_info 2618 * 2619 * nilfs_segctor_destroy() kills the segctord thread and frees 2620 * the nilfs_sc_info struct. 2621 * Caller must hold the segment semaphore. 2622 */ 2623 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci) 2624 { 2625 struct the_nilfs *nilfs = sci->sc_super->s_fs_info; 2626 int flag; 2627 2628 up_write(&nilfs->ns_segctor_sem); 2629 2630 spin_lock(&sci->sc_state_lock); 2631 nilfs_segctor_kill_thread(sci); 2632 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request 2633 || sci->sc_seq_request != sci->sc_seq_done); 2634 spin_unlock(&sci->sc_state_lock); 2635 2636 if (flag || !nilfs_segctor_confirm(sci)) 2637 nilfs_segctor_write_out(sci); 2638 2639 if (!list_empty(&sci->sc_dirty_files)) { 2640 nilfs_warning(sci->sc_super, __func__, 2641 "dirty file(s) after the final construction\n"); 2642 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1); 2643 } 2644 2645 WARN_ON(!list_empty(&sci->sc_segbufs)); 2646 WARN_ON(!list_empty(&sci->sc_write_logs)); 2647 2648 nilfs_put_root(sci->sc_root); 2649 2650 down_write(&nilfs->ns_segctor_sem); 2651 2652 del_timer_sync(&sci->sc_timer); 2653 kfree(sci); 2654 } 2655 2656 /** 2657 * nilfs_attach_log_writer - attach log writer 2658 * @sb: super block instance 2659 * @root: root object of the current filesystem tree 2660 * 2661 * This allocates a log writer object, initializes it, and starts the 2662 * log writer. 2663 * 2664 * Return Value: On success, 0 is returned. On error, one of the following 2665 * negative error code is returned. 2666 * 2667 * %-ENOMEM - Insufficient memory available. 2668 */ 2669 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root) 2670 { 2671 struct the_nilfs *nilfs = sb->s_fs_info; 2672 int err; 2673 2674 if (nilfs->ns_writer) { 2675 /* 2676 * This happens if the filesystem was remounted 2677 * read/write after nilfs_error degenerated it into a 2678 * read-only mount. 2679 */ 2680 nilfs_detach_log_writer(sb); 2681 } 2682 2683 nilfs->ns_writer = nilfs_segctor_new(sb, root); 2684 if (!nilfs->ns_writer) 2685 return -ENOMEM; 2686 2687 err = nilfs_segctor_start_thread(nilfs->ns_writer); 2688 if (err) { 2689 kfree(nilfs->ns_writer); 2690 nilfs->ns_writer = NULL; 2691 } 2692 return err; 2693 } 2694 2695 /** 2696 * nilfs_detach_log_writer - destroy log writer 2697 * @sb: super block instance 2698 * 2699 * This kills log writer daemon, frees the log writer object, and 2700 * destroys list of dirty files. 2701 */ 2702 void nilfs_detach_log_writer(struct super_block *sb) 2703 { 2704 struct the_nilfs *nilfs = sb->s_fs_info; 2705 LIST_HEAD(garbage_list); 2706 2707 down_write(&nilfs->ns_segctor_sem); 2708 if (nilfs->ns_writer) { 2709 nilfs_segctor_destroy(nilfs->ns_writer); 2710 nilfs->ns_writer = NULL; 2711 } 2712 2713 /* Force to free the list of dirty files */ 2714 spin_lock(&nilfs->ns_inode_lock); 2715 if (!list_empty(&nilfs->ns_dirty_files)) { 2716 list_splice_init(&nilfs->ns_dirty_files, &garbage_list); 2717 nilfs_warning(sb, __func__, 2718 "Hit dirty file after stopped log writer\n"); 2719 } 2720 spin_unlock(&nilfs->ns_inode_lock); 2721 up_write(&nilfs->ns_segctor_sem); 2722 2723 nilfs_dispose_list(nilfs, &garbage_list, 1); 2724 } 2725