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 folio *folio = page_folio(page);
36 struct buffer_head *bh, *head;
37 int nr_underway = 0;
38 blk_opf_t write_flags = REQ_META | REQ_PRIO | wbc_to_write_flags(wbc);
39
40 BUG_ON(!folio_test_locked(folio));
41
42 head = folio_buffers(folio);
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 folio_redirty_for_writepage(wbc, folio);
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(folio_test_writeback(folio));
73 folio_start_writeback(folio);
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 folio_unlock(folio);
84
85 if (nr_underway == 0)
86 folio_end_writeback(folio);
87
88 return 0;
89 }
90
91 const struct address_space_operations gfs2_meta_aops = {
92 .dirty_folio = block_dirty_folio,
93 .invalidate_folio = block_invalidate_folio,
94 .writepage = gfs2_aspace_writepage,
95 .release_folio = gfs2_release_folio,
96 };
97
98 const struct address_space_operations gfs2_rgrp_aops = {
99 .dirty_folio = block_dirty_folio,
100 .invalidate_folio = block_invalidate_folio,
101 .writepage = gfs2_aspace_writepage,
102 .release_folio = gfs2_release_folio,
103 };
104
105 /**
106 * gfs2_getbuf - Get a buffer with a given address space
107 * @gl: the glock
108 * @blkno: the block number (filesystem scope)
109 * @create: 1 if the buffer should be created
110 *
111 * Returns: the buffer
112 */
113
114 struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
115 {
116 struct address_space *mapping = gfs2_glock2aspace(gl);
117 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
118 struct folio *folio;
119 struct buffer_head *bh;
120 unsigned int shift;
121 unsigned long index;
122 unsigned int bufnum;
123
124 if (mapping == NULL)
125 mapping = &sdp->sd_aspace;
126
127 shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
128 index = blkno >> shift; /* convert block to page */
129 bufnum = blkno - (index << shift); /* block buf index within page */
130
131 if (create) {
132 folio = __filemap_get_folio(mapping, index,
133 FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
134 mapping_gfp_mask(mapping) | __GFP_NOFAIL);
135 bh = folio_buffers(folio);
136 if (!bh)
137 bh = create_empty_buffers(folio,
138 sdp->sd_sb.sb_bsize, 0);
139 } else {
140 folio = __filemap_get_folio(mapping, index,
141 FGP_LOCK | FGP_ACCESSED, 0);
142 if (IS_ERR(folio))
143 return NULL;
144 bh = folio_buffers(folio);
145 }
146
147 if (!bh)
148 goto out_unlock;
149
150 bh = get_nth_bh(bh, bufnum);
151 if (!buffer_mapped(bh))
152 map_bh(bh, sdp->sd_vfs, blkno);
153
154 out_unlock:
155 folio_unlock(folio);
156 folio_put(folio);
157
158 return bh;
159 }
160
161 static void meta_prep_new(struct buffer_head *bh)
162 {
163 struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
164
165 lock_buffer(bh);
166 clear_buffer_dirty(bh);
167 set_buffer_uptodate(bh);
168 unlock_buffer(bh);
169
170 mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
171 }
172
173 /**
174 * gfs2_meta_new - Get a block
175 * @gl: The glock associated with this block
176 * @blkno: The block number
177 *
178 * Returns: The buffer
179 */
180
181 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
182 {
183 struct buffer_head *bh;
184 bh = gfs2_getbuf(gl, blkno, CREATE);
185 meta_prep_new(bh);
186 return bh;
187 }
188
189 static void gfs2_meta_read_endio(struct bio *bio)
190 {
191 struct bio_vec *bvec;
192 struct bvec_iter_all iter_all;
193
194 bio_for_each_segment_all(bvec, bio, iter_all) {
195 struct page *page = bvec->bv_page;
196 struct buffer_head *bh = page_buffers(page);
197 unsigned int len = bvec->bv_len;
198
199 while (bh_offset(bh) < bvec->bv_offset)
200 bh = bh->b_this_page;
201 do {
202 struct buffer_head *next = bh->b_this_page;
203 len -= bh->b_size;
204 bh->b_end_io(bh, !bio->bi_status);
205 bh = next;
206 } while (bh && len);
207 }
208 bio_put(bio);
209 }
210
211 /*
212 * Submit several consecutive buffer head I/O requests as a single bio I/O
213 * request. (See submit_bh_wbc.)
214 */
215 static void gfs2_submit_bhs(blk_opf_t opf, struct buffer_head *bhs[], int num)
216 {
217 while (num > 0) {
218 struct buffer_head *bh = *bhs;
219 struct bio *bio;
220
221 bio = bio_alloc(bh->b_bdev, num, opf, GFP_NOIO);
222 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
223 while (num > 0) {
224 bh = *bhs;
225 if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) {
226 BUG_ON(bio->bi_iter.bi_size == 0);
227 break;
228 }
229 bhs++;
230 num--;
231 }
232 bio->bi_end_io = gfs2_meta_read_endio;
233 submit_bio(bio);
234 }
235 }
236
237 /**
238 * gfs2_meta_read - Read a block from disk
239 * @gl: The glock covering the block
240 * @blkno: The block number
241 * @flags: flags
242 * @rahead: Do read-ahead
243 * @bhp: the place where the buffer is returned (NULL on failure)
244 *
245 * Returns: errno
246 */
247
248 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
249 int rahead, struct buffer_head **bhp)
250 {
251 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
252 struct buffer_head *bh, *bhs[2];
253 int num = 0;
254
255 if (gfs2_withdrawing_or_withdrawn(sdp) &&
256 !gfs2_withdraw_in_prog(sdp)) {
257 *bhp = NULL;
258 return -EIO;
259 }
260
261 *bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
262
263 lock_buffer(bh);
264 if (buffer_uptodate(bh)) {
265 unlock_buffer(bh);
266 flags &= ~DIO_WAIT;
267 } else {
268 bh->b_end_io = end_buffer_read_sync;
269 get_bh(bh);
270 bhs[num++] = bh;
271 }
272
273 if (rahead) {
274 bh = gfs2_getbuf(gl, blkno + 1, CREATE);
275
276 lock_buffer(bh);
277 if (buffer_uptodate(bh)) {
278 unlock_buffer(bh);
279 brelse(bh);
280 } else {
281 bh->b_end_io = end_buffer_read_sync;
282 bhs[num++] = bh;
283 }
284 }
285
286 gfs2_submit_bhs(REQ_OP_READ | REQ_META | REQ_PRIO, bhs, num);
287 if (!(flags & DIO_WAIT))
288 return 0;
289
290 bh = *bhp;
291 wait_on_buffer(bh);
292 if (unlikely(!buffer_uptodate(bh))) {
293 struct gfs2_trans *tr = current->journal_info;
294 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
295 gfs2_io_error_bh_wd(sdp, bh);
296 brelse(bh);
297 *bhp = NULL;
298 return -EIO;
299 }
300
301 return 0;
302 }
303
304 /**
305 * gfs2_meta_wait - Reread a block from disk
306 * @sdp: the filesystem
307 * @bh: The block to wait for
308 *
309 * Returns: errno
310 */
311
312 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
313 {
314 if (gfs2_withdrawing_or_withdrawn(sdp) &&
315 !gfs2_withdraw_in_prog(sdp))
316 return -EIO;
317
318 wait_on_buffer(bh);
319
320 if (!buffer_uptodate(bh)) {
321 struct gfs2_trans *tr = current->journal_info;
322 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
323 gfs2_io_error_bh_wd(sdp, bh);
324 return -EIO;
325 }
326 if (gfs2_withdrawing_or_withdrawn(sdp) &&
327 !gfs2_withdraw_in_prog(sdp))
328 return -EIO;
329
330 return 0;
331 }
332
333 void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
334 {
335 struct address_space *mapping = bh->b_folio->mapping;
336 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
337 struct gfs2_bufdata *bd = bh->b_private;
338 struct gfs2_trans *tr = current->journal_info;
339 int was_pinned = 0;
340
341 if (test_clear_buffer_pinned(bh)) {
342 trace_gfs2_pin(bd, 0);
343 atomic_dec(&sdp->sd_log_pinned);
344 list_del_init(&bd->bd_list);
345 if (meta == REMOVE_META)
346 tr->tr_num_buf_rm++;
347 else
348 tr->tr_num_databuf_rm++;
349 set_bit(TR_TOUCHED, &tr->tr_flags);
350 was_pinned = 1;
351 brelse(bh);
352 }
353 if (bd) {
354 if (bd->bd_tr) {
355 gfs2_trans_add_revoke(sdp, bd);
356 } else if (was_pinned) {
357 bh->b_private = NULL;
358 kmem_cache_free(gfs2_bufdata_cachep, bd);
359 } else if (!list_empty(&bd->bd_ail_st_list) &&
360 !list_empty(&bd->bd_ail_gl_list)) {
361 gfs2_remove_from_ail(bd);
362 }
363 }
364 clear_buffer_dirty(bh);
365 clear_buffer_uptodate(bh);
366 }
367
368 /**
369 * gfs2_ail1_wipe - remove deleted/freed buffers from the ail1 list
370 * @sdp: superblock
371 * @bstart: starting block address of buffers to remove
372 * @blen: length of buffers to be removed
373 *
374 * This function is called from gfs2_journal wipe, whose job is to remove
375 * buffers, corresponding to deleted blocks, from the journal. If we find any
376 * bufdata elements on the system ail1 list, they haven't been written to
377 * the journal yet. So we remove them.
378 */
379 static void gfs2_ail1_wipe(struct gfs2_sbd *sdp, u64 bstart, u32 blen)
380 {
381 struct gfs2_trans *tr, *s;
382 struct gfs2_bufdata *bd, *bs;
383 struct buffer_head *bh;
384 u64 end = bstart + blen;
385
386 gfs2_log_lock(sdp);
387 spin_lock(&sdp->sd_ail_lock);
388 list_for_each_entry_safe(tr, s, &sdp->sd_ail1_list, tr_list) {
389 list_for_each_entry_safe(bd, bs, &tr->tr_ail1_list,
390 bd_ail_st_list) {
391 bh = bd->bd_bh;
392 if (bh->b_blocknr < bstart || bh->b_blocknr >= end)
393 continue;
394
395 gfs2_remove_from_journal(bh, REMOVE_JDATA);
396 }
397 }
398 spin_unlock(&sdp->sd_ail_lock);
399 gfs2_log_unlock(sdp);
400 }
401
402 static struct buffer_head *gfs2_getjdatabuf(struct gfs2_inode *ip, u64 blkno)
403 {
404 struct address_space *mapping = ip->i_inode.i_mapping;
405 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
406 struct folio *folio;
407 struct buffer_head *bh;
408 unsigned int shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
409 unsigned long index = blkno >> shift; /* convert block to page */
410 unsigned int bufnum = blkno - (index << shift);
411
412 folio = __filemap_get_folio(mapping, index, FGP_LOCK | FGP_ACCESSED, 0);
413 if (IS_ERR(folio))
414 return NULL;
415 bh = folio_buffers(folio);
416 if (bh)
417 bh = get_nth_bh(bh, bufnum);
418 folio_unlock(folio);
419 folio_put(folio);
420 return bh;
421 }
422
423 /**
424 * gfs2_journal_wipe - make inode's buffers so they aren't dirty/pinned anymore
425 * @ip: the inode who owns the buffers
426 * @bstart: the first buffer in the run
427 * @blen: the number of buffers in the run
428 *
429 */
430
431 void gfs2_journal_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
432 {
433 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
434 struct buffer_head *bh;
435 int ty;
436
437 if (!ip->i_gl) {
438 /* This can only happen during incomplete inode creation. */
439 BUG_ON(!test_bit(GIF_ALLOC_FAILED, &ip->i_flags));
440 return;
441 }
442
443 gfs2_ail1_wipe(sdp, bstart, blen);
444 while (blen) {
445 ty = REMOVE_META;
446 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
447 if (!bh && gfs2_is_jdata(ip)) {
448 bh = gfs2_getjdatabuf(ip, bstart);
449 ty = REMOVE_JDATA;
450 }
451 if (bh) {
452 lock_buffer(bh);
453 gfs2_log_lock(sdp);
454 spin_lock(&sdp->sd_ail_lock);
455 gfs2_remove_from_journal(bh, ty);
456 spin_unlock(&sdp->sd_ail_lock);
457 gfs2_log_unlock(sdp);
458 unlock_buffer(bh);
459 brelse(bh);
460 }
461
462 bstart++;
463 blen--;
464 }
465 }
466
467 /**
468 * gfs2_meta_buffer - Get a metadata buffer
469 * @ip: The GFS2 inode
470 * @mtype: The block type (GFS2_METATYPE_*)
471 * @num: The block number (device relative) of the buffer
472 * @bhp: the buffer is returned here
473 *
474 * Returns: errno
475 */
476
477 int gfs2_meta_buffer(struct gfs2_inode *ip, u32 mtype, u64 num,
478 struct buffer_head **bhp)
479 {
480 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
481 struct gfs2_glock *gl = ip->i_gl;
482 struct buffer_head *bh;
483 int ret = 0;
484 int rahead = 0;
485
486 if (num == ip->i_no_addr)
487 rahead = ip->i_rahead;
488
489 ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
490 if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
491 brelse(bh);
492 ret = -EIO;
493 } else {
494 *bhp = bh;
495 }
496 return ret;
497 }
498
499 /**
500 * gfs2_meta_ra - start readahead on an extent of a file
501 * @gl: the glock the blocks belong to
502 * @dblock: the starting disk block
503 * @extlen: the number of blocks in the extent
504 *
505 * returns: the first buffer in the extent
506 */
507
508 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
509 {
510 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
511 struct buffer_head *first_bh, *bh;
512 u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
513 sdp->sd_sb.sb_bsize_shift;
514
515 BUG_ON(!extlen);
516
517 if (max_ra < 1)
518 max_ra = 1;
519 if (extlen > max_ra)
520 extlen = max_ra;
521
522 first_bh = gfs2_getbuf(gl, dblock, CREATE);
523
524 if (buffer_uptodate(first_bh))
525 goto out;
526 bh_read_nowait(first_bh, REQ_META | REQ_PRIO);
527
528 dblock++;
529 extlen--;
530
531 while (extlen) {
532 bh = gfs2_getbuf(gl, dblock, CREATE);
533
534 bh_readahead(bh, REQ_RAHEAD | REQ_META | REQ_PRIO);
535 brelse(bh);
536 dblock++;
537 extlen--;
538 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
539 goto out;
540 }
541
542 wait_on_buffer(first_bh);
543 out:
544 return first_bh;
545 }
546
547
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