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
gfs2_aspace_writepage(struct page * page,struct writeback_control * wbc)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
gfs2_getbuf(struct gfs2_glock * gl,u64 blkno,int create)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 } else {
135 page = find_get_page_flags(mapping, index,
136 FGP_LOCK|FGP_ACCESSED);
137 if (!page)
138 return NULL;
139 }
140
141 if (!page_has_buffers(page))
142 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
143
144 /* Locate header for our buffer within our page */
145 for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
146 /* Do nothing */;
147 get_bh(bh);
148
149 if (!buffer_mapped(bh))
150 map_bh(bh, sdp->sd_vfs, blkno);
151
152 unlock_page(page);
153 put_page(page);
154
155 return bh;
156 }
157
meta_prep_new(struct buffer_head * bh)158 static void meta_prep_new(struct buffer_head *bh)
159 {
160 struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
161
162 lock_buffer(bh);
163 clear_buffer_dirty(bh);
164 set_buffer_uptodate(bh);
165 unlock_buffer(bh);
166
167 mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
168 }
169
170 /**
171 * gfs2_meta_new - Get a block
172 * @gl: The glock associated with this block
173 * @blkno: The block number
174 *
175 * Returns: The buffer
176 */
177
gfs2_meta_new(struct gfs2_glock * gl,u64 blkno)178 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
179 {
180 struct buffer_head *bh;
181 bh = gfs2_getbuf(gl, blkno, CREATE);
182 meta_prep_new(bh);
183 return bh;
184 }
185
gfs2_meta_read_endio(struct bio * bio)186 static void gfs2_meta_read_endio(struct bio *bio)
187 {
188 struct bio_vec *bvec;
189 struct bvec_iter_all iter_all;
190
191 bio_for_each_segment_all(bvec, bio, iter_all) {
192 struct page *page = bvec->bv_page;
193 struct buffer_head *bh = page_buffers(page);
194 unsigned int len = bvec->bv_len;
195
196 while (bh_offset(bh) < bvec->bv_offset)
197 bh = bh->b_this_page;
198 do {
199 struct buffer_head *next = bh->b_this_page;
200 len -= bh->b_size;
201 bh->b_end_io(bh, !bio->bi_status);
202 bh = next;
203 } while (bh && len);
204 }
205 bio_put(bio);
206 }
207
208 /*
209 * Submit several consecutive buffer head I/O requests as a single bio I/O
210 * request. (See submit_bh_wbc.)
211 */
gfs2_submit_bhs(int op,int op_flags,struct buffer_head * bhs[],int num)212 static void gfs2_submit_bhs(int op, int op_flags, struct buffer_head *bhs[],
213 int num)
214 {
215 while (num > 0) {
216 struct buffer_head *bh = *bhs;
217 struct bio *bio;
218
219 bio = bio_alloc(GFP_NOIO, num);
220 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
221 bio_set_dev(bio, bh->b_bdev);
222 while (num > 0) {
223 bh = *bhs;
224 if (!bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh))) {
225 BUG_ON(bio->bi_iter.bi_size == 0);
226 break;
227 }
228 bhs++;
229 num--;
230 }
231 bio->bi_end_io = gfs2_meta_read_endio;
232 bio_set_op_attrs(bio, op, op_flags);
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 * @bhp: the place where the buffer is returned (NULL on failure)
243 *
244 * Returns: errno
245 */
246
gfs2_meta_read(struct gfs2_glock * gl,u64 blkno,int flags,int rahead,struct buffer_head ** bhp)247 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
248 int rahead, struct buffer_head **bhp)
249 {
250 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
251 struct buffer_head *bh, *bhs[2];
252 int num = 0;
253
254 if (unlikely(test_bit(SDF_WITHDRAWN, &sdp->sd_flags))) {
255 *bhp = NULL;
256 return -EIO;
257 }
258
259 *bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
260
261 lock_buffer(bh);
262 if (buffer_uptodate(bh)) {
263 unlock_buffer(bh);
264 flags &= ~DIO_WAIT;
265 } else {
266 bh->b_end_io = end_buffer_read_sync;
267 get_bh(bh);
268 bhs[num++] = bh;
269 }
270
271 if (rahead) {
272 bh = gfs2_getbuf(gl, blkno + 1, CREATE);
273
274 lock_buffer(bh);
275 if (buffer_uptodate(bh)) {
276 unlock_buffer(bh);
277 brelse(bh);
278 } else {
279 bh->b_end_io = end_buffer_read_sync;
280 bhs[num++] = bh;
281 }
282 }
283
284 gfs2_submit_bhs(REQ_OP_READ, REQ_META | REQ_PRIO, bhs, num);
285 if (!(flags & DIO_WAIT))
286 return 0;
287
288 bh = *bhp;
289 wait_on_buffer(bh);
290 if (unlikely(!buffer_uptodate(bh))) {
291 struct gfs2_trans *tr = current->journal_info;
292 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
293 gfs2_io_error_bh_wd(sdp, bh);
294 brelse(bh);
295 *bhp = NULL;
296 return -EIO;
297 }
298
299 return 0;
300 }
301
302 /**
303 * gfs2_meta_wait - Reread a block from disk
304 * @sdp: the filesystem
305 * @bh: The block to wait for
306 *
307 * Returns: errno
308 */
309
gfs2_meta_wait(struct gfs2_sbd * sdp,struct buffer_head * bh)310 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
311 {
312 if (unlikely(test_bit(SDF_WITHDRAWN, &sdp->sd_flags)))
313 return -EIO;
314
315 wait_on_buffer(bh);
316
317 if (!buffer_uptodate(bh)) {
318 struct gfs2_trans *tr = current->journal_info;
319 if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
320 gfs2_io_error_bh_wd(sdp, bh);
321 return -EIO;
322 }
323 if (unlikely(test_bit(SDF_WITHDRAWN, &sdp->sd_flags)))
324 return -EIO;
325
326 return 0;
327 }
328
gfs2_remove_from_journal(struct buffer_head * bh,int meta)329 void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
330 {
331 struct address_space *mapping = bh->b_page->mapping;
332 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
333 struct gfs2_bufdata *bd = bh->b_private;
334 struct gfs2_trans *tr = current->journal_info;
335 int was_pinned = 0;
336
337 if (test_clear_buffer_pinned(bh)) {
338 trace_gfs2_pin(bd, 0);
339 atomic_dec(&sdp->sd_log_pinned);
340 list_del_init(&bd->bd_list);
341 if (meta == REMOVE_META)
342 tr->tr_num_buf_rm++;
343 else
344 tr->tr_num_databuf_rm++;
345 set_bit(TR_TOUCHED, &tr->tr_flags);
346 was_pinned = 1;
347 brelse(bh);
348 }
349 if (bd) {
350 spin_lock(&sdp->sd_ail_lock);
351 if (bd->bd_tr) {
352 gfs2_trans_add_revoke(sdp, bd);
353 } else if (was_pinned) {
354 bh->b_private = NULL;
355 kmem_cache_free(gfs2_bufdata_cachep, bd);
356 }
357 spin_unlock(&sdp->sd_ail_lock);
358 }
359 clear_buffer_dirty(bh);
360 clear_buffer_uptodate(bh);
361 }
362
363 /**
364 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
365 * @ip: the inode who owns the buffers
366 * @bstart: the first buffer in the run
367 * @blen: the number of buffers in the run
368 *
369 */
370
gfs2_meta_wipe(struct gfs2_inode * ip,u64 bstart,u32 blen)371 void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
372 {
373 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
374 struct buffer_head *bh;
375
376 while (blen) {
377 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
378 if (bh) {
379 lock_buffer(bh);
380 gfs2_log_lock(sdp);
381 gfs2_remove_from_journal(bh, REMOVE_META);
382 gfs2_log_unlock(sdp);
383 unlock_buffer(bh);
384 brelse(bh);
385 }
386
387 bstart++;
388 blen--;
389 }
390 }
391
392 /**
393 * gfs2_meta_indirect_buffer - Get a metadata buffer
394 * @ip: The GFS2 inode
395 * @height: The level of this buf in the metadata (indir addr) tree (if any)
396 * @num: The block number (device relative) of the buffer
397 * @bhp: the buffer is returned here
398 *
399 * Returns: errno
400 */
401
gfs2_meta_indirect_buffer(struct gfs2_inode * ip,int height,u64 num,struct buffer_head ** bhp)402 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
403 struct buffer_head **bhp)
404 {
405 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
406 struct gfs2_glock *gl = ip->i_gl;
407 struct buffer_head *bh;
408 int ret = 0;
409 u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
410 int rahead = 0;
411
412 if (num == ip->i_no_addr)
413 rahead = ip->i_rahead;
414
415 ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
416 if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
417 brelse(bh);
418 ret = -EIO;
419 } else {
420 *bhp = bh;
421 }
422 return ret;
423 }
424
425 /**
426 * gfs2_meta_ra - start readahead on an extent of a file
427 * @gl: the glock the blocks belong to
428 * @dblock: the starting disk block
429 * @extlen: the number of blocks in the extent
430 *
431 * returns: the first buffer in the extent
432 */
433
gfs2_meta_ra(struct gfs2_glock * gl,u64 dblock,u32 extlen)434 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
435 {
436 struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
437 struct buffer_head *first_bh, *bh;
438 u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
439 sdp->sd_sb.sb_bsize_shift;
440
441 BUG_ON(!extlen);
442
443 if (max_ra < 1)
444 max_ra = 1;
445 if (extlen > max_ra)
446 extlen = max_ra;
447
448 first_bh = gfs2_getbuf(gl, dblock, CREATE);
449
450 if (buffer_uptodate(first_bh))
451 goto out;
452 if (!buffer_locked(first_bh))
453 ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &first_bh);
454
455 dblock++;
456 extlen--;
457
458 while (extlen) {
459 bh = gfs2_getbuf(gl, dblock, CREATE);
460
461 if (!buffer_uptodate(bh) && !buffer_locked(bh))
462 ll_rw_block(REQ_OP_READ,
463 REQ_RAHEAD | REQ_META | REQ_PRIO,
464 1, &bh);
465 brelse(bh);
466 dblock++;
467 extlen--;
468 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
469 goto out;
470 }
471
472 wait_on_buffer(first_bh);
473 out:
474 return first_bh;
475 }
476
477
