1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. 5 */ 6 7 #include <linux/sched.h> 8 #include <linux/slab.h> 9 #include <linux/spinlock.h> 10 #include <linux/completion.h> 11 #include <linux/buffer_head.h> 12 #include <linux/mm.h> 13 #include <linux/pagemap.h> 14 #include <linux/writeback.h> 15 #include <linux/swap.h> 16 #include <linux/delay.h> 17 #include <linux/bio.h> 18 #include <linux/gfs2_ondisk.h> 19 20 #include "gfs2.h" 21 #include "incore.h" 22 #include "glock.h" 23 #include "glops.h" 24 #include "inode.h" 25 #include "log.h" 26 #include "lops.h" 27 #include "meta_io.h" 28 #include "rgrp.h" 29 #include "trans.h" 30 #include "util.h" 31 #include "trace_gfs2.h" 32 33 static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc) 34 { 35 struct buffer_head *bh, *head; 36 int nr_underway = 0; 37 int write_flags = REQ_META | REQ_PRIO | wbc_to_write_flags(wbc); 38 39 BUG_ON(!PageLocked(page)); 40 BUG_ON(!page_has_buffers(page)); 41 42 head = page_buffers(page); 43 bh = head; 44 45 do { 46 if (!buffer_mapped(bh)) 47 continue; 48 /* 49 * If it's a fully non-blocking write attempt and we cannot 50 * lock the buffer then redirty the page. Note that this can 51 * potentially cause a busy-wait loop from flusher thread and kswapd 52 * activity, but those code paths have their own higher-level 53 * throttling. 54 */ 55 if (wbc->sync_mode != WB_SYNC_NONE) { 56 lock_buffer(bh); 57 } else if (!trylock_buffer(bh)) { 58 redirty_page_for_writepage(wbc, page); 59 continue; 60 } 61 if (test_clear_buffer_dirty(bh)) { 62 mark_buffer_async_write(bh); 63 } else { 64 unlock_buffer(bh); 65 } 66 } while ((bh = bh->b_this_page) != head); 67 68 /* 69 * The page and its buffers are protected by PageWriteback(), so we can 70 * drop the bh refcounts early. 71 */ 72 BUG_ON(PageWriteback(page)); 73 set_page_writeback(page); 74 75 do { 76 struct buffer_head *next = bh->b_this_page; 77 if (buffer_async_write(bh)) { 78 submit_bh(REQ_OP_WRITE, write_flags, bh); 79 nr_underway++; 80 } 81 bh = next; 82 } while (bh != head); 83 unlock_page(page); 84 85 if (nr_underway == 0) 86 end_page_writeback(page); 87 88 return 0; 89 } 90 91 const struct address_space_operations gfs2_meta_aops = { 92 .writepage = gfs2_aspace_writepage, 93 .releasepage = gfs2_releasepage, 94 }; 95 96 const struct address_space_operations gfs2_rgrp_aops = { 97 .writepage = gfs2_aspace_writepage, 98 .releasepage = gfs2_releasepage, 99 }; 100 101 /** 102 * gfs2_getbuf - Get a buffer with a given address space 103 * @gl: the glock 104 * @blkno: the block number (filesystem scope) 105 * @create: 1 if the buffer should be created 106 * 107 * Returns: the buffer 108 */ 109 110 struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create) 111 { 112 struct address_space *mapping = gfs2_glock2aspace(gl); 113 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; 114 struct page *page; 115 struct buffer_head *bh; 116 unsigned int shift; 117 unsigned long index; 118 unsigned int bufnum; 119 120 if (mapping == NULL) 121 mapping = &sdp->sd_aspace; 122 123 shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift; 124 index = blkno >> shift; /* convert block to page */ 125 bufnum = blkno - (index << shift); /* block buf index within page */ 126 127 if (create) { 128 for (;;) { 129 page = grab_cache_page(mapping, index); 130 if (page) 131 break; 132 yield(); 133 } 134 if (!page_has_buffers(page)) 135 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0); 136 } else { 137 page = find_get_page_flags(mapping, index, 138 FGP_LOCK|FGP_ACCESSED); 139 if (!page) 140 return NULL; 141 if (!page_has_buffers(page)) { 142 bh = NULL; 143 goto out_unlock; 144 } 145 } 146 147 /* Locate header for our buffer within our page */ 148 for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page) 149 /* Do nothing */; 150 get_bh(bh); 151 152 if (!buffer_mapped(bh)) 153 map_bh(bh, sdp->sd_vfs, blkno); 154 155 out_unlock: 156 unlock_page(page); 157 put_page(page); 158 159 return bh; 160 } 161 162 static void meta_prep_new(struct buffer_head *bh) 163 { 164 struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data; 165 166 lock_buffer(bh); 167 clear_buffer_dirty(bh); 168 set_buffer_uptodate(bh); 169 unlock_buffer(bh); 170 171 mh->mh_magic = cpu_to_be32(GFS2_MAGIC); 172 } 173 174 /** 175 * gfs2_meta_new - Get a block 176 * @gl: The glock associated with this block 177 * @blkno: The block number 178 * 179 * Returns: The buffer 180 */ 181 182 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno) 183 { 184 struct buffer_head *bh; 185 bh = gfs2_getbuf(gl, blkno, CREATE); 186 meta_prep_new(bh); 187 return bh; 188 } 189 190 static void gfs2_meta_read_endio(struct bio *bio) 191 { 192 struct bio_vec *bvec; 193 struct bvec_iter_all iter_all; 194 195 bio_for_each_segment_all(bvec, bio, iter_all) { 196 struct page *page = bvec->bv_page; 197 struct buffer_head *bh = page_buffers(page); 198 unsigned int len = bvec->bv_len; 199 200 while (bh_offset(bh) < bvec->bv_offset) 201 bh = bh->b_this_page; 202 do { 203 struct buffer_head *next = bh->b_this_page; 204 len -= bh->b_size; 205 bh->b_end_io(bh, !bio->bi_status); 206 bh = next; 207 } while (bh && len); 208 } 209 bio_put(bio); 210 } 211 212 /* 213 * Submit several consecutive buffer head I/O requests as a single bio I/O 214 * request. (See submit_bh_wbc.) 215 */ 216 static void gfs2_submit_bhs(int op, int op_flags, struct buffer_head *bhs[], 217 int num) 218 { 219 while (num > 0) { 220 struct buffer_head *bh = *bhs; 221 struct bio *bio; 222 223 bio = bio_alloc(GFP_NOIO, num); 224 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); 225 bio_set_dev(bio, bh->b_bdev); 226 while (num > 0) { 227 bh = *bhs; 228 if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) { 229 BUG_ON(bio->bi_iter.bi_size == 0); 230 break; 231 } 232 bhs++; 233 num--; 234 } 235 bio->bi_end_io = gfs2_meta_read_endio; 236 bio_set_op_attrs(bio, op, op_flags); 237 submit_bio(bio); 238 } 239 } 240 241 /** 242 * gfs2_meta_read - Read a block from disk 243 * @gl: The glock covering the block 244 * @blkno: The block number 245 * @flags: flags 246 * @rahead: Do read-ahead 247 * @bhp: the place where the buffer is returned (NULL on failure) 248 * 249 * Returns: errno 250 */ 251 252 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags, 253 int rahead, struct buffer_head **bhp) 254 { 255 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; 256 struct buffer_head *bh, *bhs[2]; 257 int num = 0; 258 259 if (unlikely(gfs2_withdrawn(sdp)) && 260 (!sdp->sd_jdesc || gl != sdp->sd_jinode_gl)) { 261 *bhp = NULL; 262 return -EIO; 263 } 264 265 *bhp = bh = gfs2_getbuf(gl, blkno, CREATE); 266 267 lock_buffer(bh); 268 if (buffer_uptodate(bh)) { 269 unlock_buffer(bh); 270 flags &= ~DIO_WAIT; 271 } else { 272 bh->b_end_io = end_buffer_read_sync; 273 get_bh(bh); 274 bhs[num++] = bh; 275 } 276 277 if (rahead) { 278 bh = gfs2_getbuf(gl, blkno + 1, CREATE); 279 280 lock_buffer(bh); 281 if (buffer_uptodate(bh)) { 282 unlock_buffer(bh); 283 brelse(bh); 284 } else { 285 bh->b_end_io = end_buffer_read_sync; 286 bhs[num++] = bh; 287 } 288 } 289 290 gfs2_submit_bhs(REQ_OP_READ, REQ_META | REQ_PRIO, bhs, num); 291 if (!(flags & DIO_WAIT)) 292 return 0; 293 294 bh = *bhp; 295 wait_on_buffer(bh); 296 if (unlikely(!buffer_uptodate(bh))) { 297 struct gfs2_trans *tr = current->journal_info; 298 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags)) 299 gfs2_io_error_bh_wd(sdp, bh); 300 brelse(bh); 301 *bhp = NULL; 302 return -EIO; 303 } 304 305 return 0; 306 } 307 308 /** 309 * gfs2_meta_wait - Reread a block from disk 310 * @sdp: the filesystem 311 * @bh: The block to wait for 312 * 313 * Returns: errno 314 */ 315 316 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh) 317 { 318 if (unlikely(gfs2_withdrawn(sdp))) 319 return -EIO; 320 321 wait_on_buffer(bh); 322 323 if (!buffer_uptodate(bh)) { 324 struct gfs2_trans *tr = current->journal_info; 325 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags)) 326 gfs2_io_error_bh_wd(sdp, bh); 327 return -EIO; 328 } 329 if (unlikely(gfs2_withdrawn(sdp))) 330 return -EIO; 331 332 return 0; 333 } 334 335 void gfs2_remove_from_journal(struct buffer_head *bh, int meta) 336 { 337 struct address_space *mapping = bh->b_page->mapping; 338 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping); 339 struct gfs2_bufdata *bd = bh->b_private; 340 struct gfs2_trans *tr = current->journal_info; 341 int was_pinned = 0; 342 343 if (test_clear_buffer_pinned(bh)) { 344 trace_gfs2_pin(bd, 0); 345 atomic_dec(&sdp->sd_log_pinned); 346 list_del_init(&bd->bd_list); 347 if (meta == REMOVE_META) 348 tr->tr_num_buf_rm++; 349 else 350 tr->tr_num_databuf_rm++; 351 set_bit(TR_TOUCHED, &tr->tr_flags); 352 was_pinned = 1; 353 brelse(bh); 354 } 355 if (bd) { 356 if (bd->bd_tr) { 357 gfs2_trans_add_revoke(sdp, bd); 358 } else if (was_pinned) { 359 bh->b_private = NULL; 360 kmem_cache_free(gfs2_bufdata_cachep, bd); 361 } else if (!list_empty(&bd->bd_ail_st_list) && 362 !list_empty(&bd->bd_ail_gl_list)) { 363 gfs2_remove_from_ail(bd); 364 } 365 } 366 clear_buffer_dirty(bh); 367 clear_buffer_uptodate(bh); 368 } 369 370 /** 371 * gfs2_ail1_wipe - remove deleted/freed buffers from the ail1 list 372 * @sdp: superblock 373 * @bstart: starting block address of buffers to remove 374 * @blen: length of buffers to be removed 375 * 376 * This function is called from gfs2_journal wipe, whose job is to remove 377 * buffers, corresponding to deleted blocks, from the journal. If we find any 378 * bufdata elements on the system ail1 list, they haven't been written to 379 * the journal yet. So we remove them. 380 */ 381 static void gfs2_ail1_wipe(struct gfs2_sbd *sdp, u64 bstart, u32 blen) 382 { 383 struct gfs2_trans *tr, *s; 384 struct gfs2_bufdata *bd, *bs; 385 struct buffer_head *bh; 386 u64 end = bstart + blen; 387 388 gfs2_log_lock(sdp); 389 spin_lock(&sdp->sd_ail_lock); 390 list_for_each_entry_safe(tr, s, &sdp->sd_ail1_list, tr_list) { 391 list_for_each_entry_safe(bd, bs, &tr->tr_ail1_list, 392 bd_ail_st_list) { 393 bh = bd->bd_bh; 394 if (bh->b_blocknr < bstart || bh->b_blocknr >= end) 395 continue; 396 397 gfs2_remove_from_journal(bh, REMOVE_JDATA); 398 } 399 } 400 spin_unlock(&sdp->sd_ail_lock); 401 gfs2_log_unlock(sdp); 402 } 403 404 static struct buffer_head *gfs2_getjdatabuf(struct gfs2_inode *ip, u64 blkno) 405 { 406 struct address_space *mapping = ip->i_inode.i_mapping; 407 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 408 struct page *page; 409 struct buffer_head *bh; 410 unsigned int shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift; 411 unsigned long index = blkno >> shift; /* convert block to page */ 412 unsigned int bufnum = blkno - (index << shift); 413 414 page = find_get_page_flags(mapping, index, FGP_LOCK|FGP_ACCESSED); 415 if (!page) 416 return NULL; 417 if (!page_has_buffers(page)) { 418 unlock_page(page); 419 put_page(page); 420 return NULL; 421 } 422 /* Locate header for our buffer within our page */ 423 for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page) 424 /* Do nothing */; 425 get_bh(bh); 426 unlock_page(page); 427 put_page(page); 428 return bh; 429 } 430 431 /** 432 * gfs2_journal_wipe - make inode's buffers so they aren't dirty/pinned anymore 433 * @ip: the inode who owns the buffers 434 * @bstart: the first buffer in the run 435 * @blen: the number of buffers in the run 436 * 437 */ 438 439 void gfs2_journal_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen) 440 { 441 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 442 struct buffer_head *bh; 443 int ty; 444 445 gfs2_ail1_wipe(sdp, bstart, blen); 446 while (blen) { 447 ty = REMOVE_META; 448 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE); 449 if (!bh && gfs2_is_jdata(ip)) { 450 bh = gfs2_getjdatabuf(ip, bstart); 451 ty = REMOVE_JDATA; 452 } 453 if (bh) { 454 lock_buffer(bh); 455 gfs2_log_lock(sdp); 456 spin_lock(&sdp->sd_ail_lock); 457 gfs2_remove_from_journal(bh, ty); 458 spin_unlock(&sdp->sd_ail_lock); 459 gfs2_log_unlock(sdp); 460 unlock_buffer(bh); 461 brelse(bh); 462 } 463 464 bstart++; 465 blen--; 466 } 467 } 468 469 /** 470 * gfs2_meta_buffer - Get a metadata buffer 471 * @ip: The GFS2 inode 472 * @mtype: The block type (GFS2_METATYPE_*) 473 * @num: The block number (device relative) of the buffer 474 * @bhp: the buffer is returned here 475 * 476 * Returns: errno 477 */ 478 479 int gfs2_meta_buffer(struct gfs2_inode *ip, u32 mtype, u64 num, 480 struct buffer_head **bhp) 481 { 482 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 483 struct gfs2_glock *gl = ip->i_gl; 484 struct buffer_head *bh; 485 int ret = 0; 486 int rahead = 0; 487 488 if (num == ip->i_no_addr) 489 rahead = ip->i_rahead; 490 491 ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh); 492 if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) { 493 brelse(bh); 494 ret = -EIO; 495 } else { 496 *bhp = bh; 497 } 498 return ret; 499 } 500 501 /** 502 * gfs2_meta_ra - start readahead on an extent of a file 503 * @gl: the glock the blocks belong to 504 * @dblock: the starting disk block 505 * @extlen: the number of blocks in the extent 506 * 507 * returns: the first buffer in the extent 508 */ 509 510 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen) 511 { 512 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; 513 struct buffer_head *first_bh, *bh; 514 u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >> 515 sdp->sd_sb.sb_bsize_shift; 516 517 BUG_ON(!extlen); 518 519 if (max_ra < 1) 520 max_ra = 1; 521 if (extlen > max_ra) 522 extlen = max_ra; 523 524 first_bh = gfs2_getbuf(gl, dblock, CREATE); 525 526 if (buffer_uptodate(first_bh)) 527 goto out; 528 if (!buffer_locked(first_bh)) 529 ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &first_bh); 530 531 dblock++; 532 extlen--; 533 534 while (extlen) { 535 bh = gfs2_getbuf(gl, dblock, CREATE); 536 537 if (!buffer_uptodate(bh) && !buffer_locked(bh)) 538 ll_rw_block(REQ_OP_READ, 539 REQ_RAHEAD | REQ_META | REQ_PRIO, 540 1, &bh); 541 brelse(bh); 542 dblock++; 543 extlen--; 544 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh)) 545 goto out; 546 } 547 548 wait_on_buffer(first_bh); 549 out: 550 return first_bh; 551 } 552 553