xref: /openbmc/linux/fs/btrfs/bio.c (revision 1c2b3ee3b0ec4bc971e23fe18d4c92333a6ad18a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  * Copyright (C) 2022 Christoph Hellwig.
5  */
6 
7 #include <linux/bio.h>
8 #include "bio.h"
9 #include "ctree.h"
10 #include "volumes.h"
11 #include "raid56.h"
12 #include "async-thread.h"
13 #include "check-integrity.h"
14 #include "dev-replace.h"
15 #include "rcu-string.h"
16 #include "zoned.h"
17 #include "file-item.h"
18 
19 static struct bio_set btrfs_bioset;
20 
21 /*
22  * Initialize a btrfs_bio structure.  This skips the embedded bio itself as it
23  * is already initialized by the block layer.
24  */
25 static inline void btrfs_bio_init(struct btrfs_bio *bbio,
26 				  struct btrfs_inode *inode,
27 				  btrfs_bio_end_io_t end_io, void *private)
28 {
29 	memset(bbio, 0, offsetof(struct btrfs_bio, bio));
30 	bbio->inode = inode;
31 	bbio->end_io = end_io;
32 	bbio->private = private;
33 }
34 
35 /*
36  * Allocate a btrfs_bio structure.  The btrfs_bio is the main I/O container for
37  * btrfs, and is used for all I/O submitted through btrfs_submit_bio.
38  *
39  * Just like the underlying bio_alloc_bioset it will not fail as it is backed by
40  * a mempool.
41  */
42 struct bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
43 			    struct btrfs_inode *inode,
44 			    btrfs_bio_end_io_t end_io, void *private)
45 {
46 	struct bio *bio;
47 
48 	bio = bio_alloc_bioset(NULL, nr_vecs, opf, GFP_NOFS, &btrfs_bioset);
49 	btrfs_bio_init(btrfs_bio(bio), inode, end_io, private);
50 	return bio;
51 }
52 
53 struct bio *btrfs_bio_clone_partial(struct bio *orig, u64 offset, u64 size,
54 				    struct btrfs_inode *inode,
55 				    btrfs_bio_end_io_t end_io, void *private)
56 {
57 	struct bio *bio;
58 	struct btrfs_bio *bbio;
59 
60 	ASSERT(offset <= UINT_MAX && size <= UINT_MAX);
61 
62 	bio = bio_alloc_clone(orig->bi_bdev, orig, GFP_NOFS, &btrfs_bioset);
63 	bbio = btrfs_bio(bio);
64 	btrfs_bio_init(bbio, inode, end_io, private);
65 
66 	bio_trim(bio, offset >> 9, size >> 9);
67 	return bio;
68 }
69 
70 static void btrfs_log_dev_io_error(struct bio *bio, struct btrfs_device *dev)
71 {
72 	if (!dev || !dev->bdev)
73 		return;
74 	if (bio->bi_status != BLK_STS_IOERR && bio->bi_status != BLK_STS_TARGET)
75 		return;
76 
77 	if (btrfs_op(bio) == BTRFS_MAP_WRITE)
78 		btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
79 	if (!(bio->bi_opf & REQ_RAHEAD))
80 		btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
81 	if (bio->bi_opf & REQ_PREFLUSH)
82 		btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_FLUSH_ERRS);
83 }
84 
85 static struct workqueue_struct *btrfs_end_io_wq(struct btrfs_fs_info *fs_info,
86 						struct bio *bio)
87 {
88 	if (bio->bi_opf & REQ_META)
89 		return fs_info->endio_meta_workers;
90 	return fs_info->endio_workers;
91 }
92 
93 static void btrfs_end_bio_work(struct work_struct *work)
94 {
95 	struct btrfs_bio *bbio = container_of(work, struct btrfs_bio, end_io_work);
96 
97 	bbio->end_io(bbio);
98 }
99 
100 static void btrfs_simple_end_io(struct bio *bio)
101 {
102 	struct btrfs_fs_info *fs_info = bio->bi_private;
103 	struct btrfs_bio *bbio = btrfs_bio(bio);
104 
105 	btrfs_bio_counter_dec(fs_info);
106 
107 	if (bio->bi_status)
108 		btrfs_log_dev_io_error(bio, bbio->device);
109 
110 	if (bio_op(bio) == REQ_OP_READ) {
111 		INIT_WORK(&bbio->end_io_work, btrfs_end_bio_work);
112 		queue_work(btrfs_end_io_wq(fs_info, bio), &bbio->end_io_work);
113 	} else {
114 		bbio->end_io(bbio);
115 	}
116 }
117 
118 static void btrfs_raid56_end_io(struct bio *bio)
119 {
120 	struct btrfs_io_context *bioc = bio->bi_private;
121 	struct btrfs_bio *bbio = btrfs_bio(bio);
122 
123 	btrfs_bio_counter_dec(bioc->fs_info);
124 	bbio->mirror_num = bioc->mirror_num;
125 	bbio->end_io(bbio);
126 
127 	btrfs_put_bioc(bioc);
128 }
129 
130 static void btrfs_orig_write_end_io(struct bio *bio)
131 {
132 	struct btrfs_io_stripe *stripe = bio->bi_private;
133 	struct btrfs_io_context *bioc = stripe->bioc;
134 	struct btrfs_bio *bbio = btrfs_bio(bio);
135 
136 	btrfs_bio_counter_dec(bioc->fs_info);
137 
138 	if (bio->bi_status) {
139 		atomic_inc(&bioc->error);
140 		btrfs_log_dev_io_error(bio, stripe->dev);
141 	}
142 
143 	/*
144 	 * Only send an error to the higher layers if it is beyond the tolerance
145 	 * threshold.
146 	 */
147 	if (atomic_read(&bioc->error) > bioc->max_errors)
148 		bio->bi_status = BLK_STS_IOERR;
149 	else
150 		bio->bi_status = BLK_STS_OK;
151 
152 	bbio->end_io(bbio);
153 	btrfs_put_bioc(bioc);
154 }
155 
156 static void btrfs_clone_write_end_io(struct bio *bio)
157 {
158 	struct btrfs_io_stripe *stripe = bio->bi_private;
159 
160 	if (bio->bi_status) {
161 		atomic_inc(&stripe->bioc->error);
162 		btrfs_log_dev_io_error(bio, stripe->dev);
163 	}
164 
165 	/* Pass on control to the original bio this one was cloned from */
166 	bio_endio(stripe->bioc->orig_bio);
167 	bio_put(bio);
168 }
169 
170 static void btrfs_submit_dev_bio(struct btrfs_device *dev, struct bio *bio)
171 {
172 	if (!dev || !dev->bdev ||
173 	    test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) ||
174 	    (btrfs_op(bio) == BTRFS_MAP_WRITE &&
175 	     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) {
176 		bio_io_error(bio);
177 		return;
178 	}
179 
180 	bio_set_dev(bio, dev->bdev);
181 
182 	/*
183 	 * For zone append writing, bi_sector must point the beginning of the
184 	 * zone
185 	 */
186 	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
187 		u64 physical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
188 
189 		if (btrfs_dev_is_sequential(dev, physical)) {
190 			u64 zone_start = round_down(physical,
191 						    dev->fs_info->zone_size);
192 
193 			bio->bi_iter.bi_sector = zone_start >> SECTOR_SHIFT;
194 		} else {
195 			bio->bi_opf &= ~REQ_OP_ZONE_APPEND;
196 			bio->bi_opf |= REQ_OP_WRITE;
197 		}
198 	}
199 	btrfs_debug_in_rcu(dev->fs_info,
200 	"%s: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u",
201 		__func__, bio_op(bio), bio->bi_opf, bio->bi_iter.bi_sector,
202 		(unsigned long)dev->bdev->bd_dev, btrfs_dev_name(dev),
203 		dev->devid, bio->bi_iter.bi_size);
204 
205 	btrfsic_check_bio(bio);
206 	submit_bio(bio);
207 }
208 
209 static void btrfs_submit_mirrored_bio(struct btrfs_io_context *bioc, int dev_nr)
210 {
211 	struct bio *orig_bio = bioc->orig_bio, *bio;
212 
213 	ASSERT(bio_op(orig_bio) != REQ_OP_READ);
214 
215 	/* Reuse the bio embedded into the btrfs_bio for the last mirror */
216 	if (dev_nr == bioc->num_stripes - 1) {
217 		bio = orig_bio;
218 		bio->bi_end_io = btrfs_orig_write_end_io;
219 	} else {
220 		bio = bio_alloc_clone(NULL, orig_bio, GFP_NOFS, &fs_bio_set);
221 		bio_inc_remaining(orig_bio);
222 		bio->bi_end_io = btrfs_clone_write_end_io;
223 	}
224 
225 	bio->bi_private = &bioc->stripes[dev_nr];
226 	bio->bi_iter.bi_sector = bioc->stripes[dev_nr].physical >> SECTOR_SHIFT;
227 	bioc->stripes[dev_nr].bioc = bioc;
228 	btrfs_submit_dev_bio(bioc->stripes[dev_nr].dev, bio);
229 }
230 
231 void btrfs_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio, int mirror_num)
232 {
233 	struct btrfs_bio *bbio = btrfs_bio(bio);
234 	u64 logical = bio->bi_iter.bi_sector << 9;
235 	u64 length = bio->bi_iter.bi_size;
236 	u64 map_length = length;
237 	struct btrfs_io_context *bioc = NULL;
238 	struct btrfs_io_stripe smap;
239 	blk_status_t ret;
240 	int error;
241 
242 	btrfs_bio_counter_inc_blocked(fs_info);
243 	error = __btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
244 				  &bioc, &smap, &mirror_num, 1);
245 	if (error) {
246 		ret = errno_to_blk_status(error);
247 		goto fail;
248 	}
249 
250 	if (map_length < length) {
251 		btrfs_crit(fs_info,
252 			   "mapping failed logical %llu bio len %llu len %llu",
253 			   logical, length, map_length);
254 		BUG();
255 	}
256 
257 	/*
258 	 * Save the iter for the end_io handler and preload the checksums for
259 	 * data reads.
260 	 */
261 	if (bio_op(bio) == REQ_OP_READ && !(bio->bi_opf & REQ_META)) {
262 		bbio->iter = bio->bi_iter;
263 		ret = btrfs_lookup_bio_sums(bbio);
264 		if (ret)
265 			goto fail;
266 	}
267 
268 	if (!bioc) {
269 		/* Single mirror read/write fast path */
270 		bbio->mirror_num = mirror_num;
271 		bbio->device = smap.dev;
272 		bio->bi_iter.bi_sector = smap.physical >> SECTOR_SHIFT;
273 		bio->bi_private = fs_info;
274 		bio->bi_end_io = btrfs_simple_end_io;
275 		btrfs_submit_dev_bio(smap.dev, bio);
276 	} else if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
277 		/* Parity RAID write or read recovery */
278 		bio->bi_private = bioc;
279 		bio->bi_end_io = btrfs_raid56_end_io;
280 		if (bio_op(bio) == REQ_OP_READ)
281 			raid56_parity_recover(bio, bioc, mirror_num);
282 		else
283 			raid56_parity_write(bio, bioc);
284 	} else {
285 		/* Write to multiple mirrors */
286 		int total_devs = bioc->num_stripes;
287 		int dev_nr;
288 
289 		bioc->orig_bio = bio;
290 		for (dev_nr = 0; dev_nr < total_devs; dev_nr++)
291 			btrfs_submit_mirrored_bio(bioc, dev_nr);
292 	}
293 	return;
294 
295 fail:
296 	btrfs_bio_counter_dec(fs_info);
297 	btrfs_bio_end_io(bbio, ret);
298 }
299 
300 /*
301  * Submit a repair write.
302  *
303  * This bypasses btrfs_submit_bio deliberately, as that writes all copies in a
304  * RAID setup.  Here we only want to write the one bad copy, so we do the
305  * mapping ourselves and submit the bio directly.
306  *
307  * The I/O is issued synchronously to block the repair read completion from
308  * freeing the bio.
309  */
310 int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
311 			    u64 length, u64 logical, struct page *page,
312 			    unsigned int pg_offset, int mirror_num)
313 {
314 	struct btrfs_device *dev;
315 	struct bio_vec bvec;
316 	struct bio bio;
317 	u64 map_length = 0;
318 	u64 sector;
319 	struct btrfs_io_context *bioc = NULL;
320 	int ret = 0;
321 
322 	ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
323 	BUG_ON(!mirror_num);
324 
325 	if (btrfs_repair_one_zone(fs_info, logical))
326 		return 0;
327 
328 	map_length = length;
329 
330 	/*
331 	 * Avoid races with device replace and make sure our bioc has devices
332 	 * associated to its stripes that don't go away while we are doing the
333 	 * read repair operation.
334 	 */
335 	btrfs_bio_counter_inc_blocked(fs_info);
336 	if (btrfs_is_parity_mirror(fs_info, logical, length)) {
337 		/*
338 		 * Note that we don't use BTRFS_MAP_WRITE because it's supposed
339 		 * to update all raid stripes, but here we just want to correct
340 		 * bad stripe, thus BTRFS_MAP_READ is abused to only get the bad
341 		 * stripe's dev and sector.
342 		 */
343 		ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical,
344 				      &map_length, &bioc, 0);
345 		if (ret)
346 			goto out_counter_dec;
347 		ASSERT(bioc->mirror_num == 1);
348 	} else {
349 		ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
350 				      &map_length, &bioc, mirror_num);
351 		if (ret)
352 			goto out_counter_dec;
353 		/*
354 		 * This happens when dev-replace is also running, and the
355 		 * mirror_num indicates the dev-replace target.
356 		 *
357 		 * In this case, we don't need to do anything, as the read
358 		 * error just means the replace progress hasn't reached our
359 		 * read range, and later replace routine would handle it well.
360 		 */
361 		if (mirror_num != bioc->mirror_num)
362 			goto out_counter_dec;
363 	}
364 
365 	sector = bioc->stripes[bioc->mirror_num - 1].physical >> 9;
366 	dev = bioc->stripes[bioc->mirror_num - 1].dev;
367 	btrfs_put_bioc(bioc);
368 
369 	if (!dev || !dev->bdev ||
370 	    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
371 		ret = -EIO;
372 		goto out_counter_dec;
373 	}
374 
375 	bio_init(&bio, dev->bdev, &bvec, 1, REQ_OP_WRITE | REQ_SYNC);
376 	bio.bi_iter.bi_sector = sector;
377 	__bio_add_page(&bio, page, length, pg_offset);
378 
379 	btrfsic_check_bio(&bio);
380 	ret = submit_bio_wait(&bio);
381 	if (ret) {
382 		/* try to remap that extent elsewhere? */
383 		btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
384 		goto out_bio_uninit;
385 	}
386 
387 	btrfs_info_rl_in_rcu(fs_info,
388 		"read error corrected: ino %llu off %llu (dev %s sector %llu)",
389 			     ino, start, btrfs_dev_name(dev), sector);
390 	ret = 0;
391 
392 out_bio_uninit:
393 	bio_uninit(&bio);
394 out_counter_dec:
395 	btrfs_bio_counter_dec(fs_info);
396 	return ret;
397 }
398 
399 int __init btrfs_bioset_init(void)
400 {
401 	if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE,
402 			offsetof(struct btrfs_bio, bio),
403 			BIOSET_NEED_BVECS))
404 		return -ENOMEM;
405 	return 0;
406 }
407 
408 void __cold btrfs_bioset_exit(void)
409 {
410 	bioset_exit(&btrfs_bioset);
411 }
412