1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or https://opensource.org/licenses/CDDL-1.0.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (C) 2008-2010 Lawrence Livermore National Security, LLC.
23 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
24 * Rewritten for Linux by Brian Behlendorf <behlendorf1@llnl.gov>.
25 * LLNL-CODE-403049.
26 * Copyright (c) 2012, 2019 by Delphix. All rights reserved.
27 * Copyright (c) 2023, 2024, Klara Inc.
28 */
29
30 #include <sys/zfs_context.h>
31 #include <sys/spa_impl.h>
32 #include <sys/vdev_disk.h>
33 #include <sys/vdev_impl.h>
34 #include <sys/vdev_trim.h>
35 #include <sys/abd.h>
36 #include <sys/fs/zfs.h>
37 #include <sys/zio.h>
38 #include <linux/blkpg.h>
39 #include <linux/msdos_fs.h>
40 #include <linux/vfs_compat.h>
41 #include <linux/blk-cgroup.h>
42
43 /*
44 * Linux 6.8.x uses a bdev_handle as an instance/refcount for an underlying
45 * block_device. Since it carries the block_device inside, its convenient to
46 * just use the handle as a proxy.
47 *
48 * Linux 6.9.x uses a file for the same purpose.
49 *
50 * For pre-6.8, we just emulate this with a cast, since we don't need any of
51 * the other fields inside the handle.
52 */
53 #if defined(HAVE_BDEV_OPEN_BY_PATH)
54 typedef struct bdev_handle zfs_bdev_handle_t;
55 #define BDH_BDEV(bdh) ((bdh)->bdev)
56 #define BDH_IS_ERR(bdh) (IS_ERR(bdh))
57 #define BDH_PTR_ERR(bdh) (PTR_ERR(bdh))
58 #define BDH_ERR_PTR(err) (ERR_PTR(err))
59 #elif defined(HAVE_BDEV_FILE_OPEN_BY_PATH)
60 typedef struct file zfs_bdev_handle_t;
61 #define BDH_BDEV(bdh) (file_bdev(bdh))
62 #define BDH_IS_ERR(bdh) (IS_ERR(bdh))
63 #define BDH_PTR_ERR(bdh) (PTR_ERR(bdh))
64 #define BDH_ERR_PTR(err) (ERR_PTR(err))
65 #else
66 typedef void zfs_bdev_handle_t;
67 #define BDH_BDEV(bdh) ((struct block_device *)bdh)
68 #define BDH_IS_ERR(bdh) (IS_ERR(BDH_BDEV(bdh)))
69 #define BDH_PTR_ERR(bdh) (PTR_ERR(BDH_BDEV(bdh)))
70 #define BDH_ERR_PTR(err) (ERR_PTR(err))
71 #endif
72
73 typedef struct vdev_disk {
74 zfs_bdev_handle_t *vd_bdh;
75 krwlock_t vd_lock;
76 } vdev_disk_t;
77
78 /*
79 * Maximum number of segments to add to a bio (min 4). If this is higher than
80 * the maximum allowed by the device queue or the kernel itself, it will be
81 * clamped. Setting it to zero will cause the kernel's ideal size to be used.
82 */
83 uint_t zfs_vdev_disk_max_segs = 0;
84
85 /*
86 * Unique identifier for the exclusive vdev holder.
87 */
88 static void *zfs_vdev_holder = VDEV_HOLDER;
89
90 /*
91 * Wait up to zfs_vdev_open_timeout_ms milliseconds before determining the
92 * device is missing. The missing path may be transient since the links
93 * can be briefly removed and recreated in response to udev events.
94 */
95 static uint_t zfs_vdev_open_timeout_ms = 1000;
96
97 /*
98 * Size of the "reserved" partition, in blocks.
99 */
100 #define EFI_MIN_RESV_SIZE (16 * 1024)
101
102 /*
103 * BIO request failfast mask.
104 */
105
106 static unsigned int zfs_vdev_failfast_mask = 1;
107
108 /*
109 * Convert SPA mode flags into bdev open mode flags.
110 */
111 #ifdef HAVE_BLK_MODE_T
112 typedef blk_mode_t vdev_bdev_mode_t;
113 #define VDEV_BDEV_MODE_READ BLK_OPEN_READ
114 #define VDEV_BDEV_MODE_WRITE BLK_OPEN_WRITE
115 #define VDEV_BDEV_MODE_EXCL BLK_OPEN_EXCL
116 #define VDEV_BDEV_MODE_MASK (BLK_OPEN_READ|BLK_OPEN_WRITE|BLK_OPEN_EXCL)
117 #else
118 typedef fmode_t vdev_bdev_mode_t;
119 #define VDEV_BDEV_MODE_READ FMODE_READ
120 #define VDEV_BDEV_MODE_WRITE FMODE_WRITE
121 #define VDEV_BDEV_MODE_EXCL FMODE_EXCL
122 #define VDEV_BDEV_MODE_MASK (FMODE_READ|FMODE_WRITE|FMODE_EXCL)
123 #endif
124
125 static vdev_bdev_mode_t
vdev_bdev_mode(spa_mode_t smode)126 vdev_bdev_mode(spa_mode_t smode)
127 {
128 ASSERT3U(smode, !=, SPA_MODE_UNINIT);
129 ASSERT0(smode & ~(SPA_MODE_READ|SPA_MODE_WRITE));
130
131 vdev_bdev_mode_t bmode = VDEV_BDEV_MODE_EXCL;
132
133 if (smode & SPA_MODE_READ)
134 bmode |= VDEV_BDEV_MODE_READ;
135
136 if (smode & SPA_MODE_WRITE)
137 bmode |= VDEV_BDEV_MODE_WRITE;
138
139 ASSERT(bmode & VDEV_BDEV_MODE_MASK);
140 ASSERT0(bmode & ~VDEV_BDEV_MODE_MASK);
141
142 return (bmode);
143 }
144
145 /*
146 * Returns the usable capacity (in bytes) for the partition or disk.
147 */
148 static uint64_t
bdev_capacity(struct block_device * bdev)149 bdev_capacity(struct block_device *bdev)
150 {
151 #ifdef HAVE_BDEV_NR_BYTES
152 return (bdev_nr_bytes(bdev));
153 #else
154 return (i_size_read(bdev->bd_inode));
155 #endif
156 }
157
158 #if !defined(HAVE_BDEV_WHOLE)
159 static inline struct block_device *
bdev_whole(struct block_device * bdev)160 bdev_whole(struct block_device *bdev)
161 {
162 return (bdev->bd_contains);
163 }
164 #endif
165
166 #if defined(HAVE_BDEVNAME)
167 #define vdev_bdevname(bdev, name) bdevname(bdev, name)
168 #else
169 static inline void
vdev_bdevname(struct block_device * bdev,char * name)170 vdev_bdevname(struct block_device *bdev, char *name)
171 {
172 snprintf(name, BDEVNAME_SIZE, "%pg", bdev);
173 }
174 #endif
175
176 /*
177 * Returns the maximum expansion capacity of the block device (in bytes).
178 *
179 * It is possible to expand a vdev when it has been created as a wholedisk
180 * and the containing block device has increased in capacity. Or when the
181 * partition containing the pool has been manually increased in size.
182 *
183 * This function is only responsible for calculating the potential expansion
184 * size so it can be reported by 'zpool list'. The efi_use_whole_disk() is
185 * responsible for verifying the expected partition layout in the wholedisk
186 * case, and updating the partition table if appropriate. Once the partition
187 * size has been increased the additional capacity will be visible using
188 * bdev_capacity().
189 *
190 * The returned maximum expansion capacity is always expected to be larger, or
191 * at the very least equal, to its usable capacity to prevent overestimating
192 * the pool expandsize.
193 */
194 static uint64_t
bdev_max_capacity(struct block_device * bdev,uint64_t wholedisk)195 bdev_max_capacity(struct block_device *bdev, uint64_t wholedisk)
196 {
197 uint64_t psize;
198 int64_t available;
199
200 if (wholedisk && bdev != bdev_whole(bdev)) {
201 /*
202 * When reporting maximum expansion capacity for a wholedisk
203 * deduct any capacity which is expected to be lost due to
204 * alignment restrictions. Over reporting this value isn't
205 * harmful and would only result in slightly less capacity
206 * than expected post expansion.
207 * The estimated available space may be slightly smaller than
208 * bdev_capacity() for devices where the number of sectors is
209 * not a multiple of the alignment size and the partition layout
210 * is keeping less than PARTITION_END_ALIGNMENT bytes after the
211 * "reserved" EFI partition: in such cases return the device
212 * usable capacity.
213 */
214 available = bdev_capacity(bdev_whole(bdev)) -
215 ((EFI_MIN_RESV_SIZE + NEW_START_BLOCK +
216 PARTITION_END_ALIGNMENT) << SECTOR_BITS);
217 psize = MAX(available, bdev_capacity(bdev));
218 } else {
219 psize = bdev_capacity(bdev);
220 }
221
222 return (psize);
223 }
224
225 static void
vdev_disk_error(zio_t * zio)226 vdev_disk_error(zio_t *zio)
227 {
228 /*
229 * This function can be called in interrupt context, for instance while
230 * handling IRQs coming from a misbehaving disk device; use printk()
231 * which is safe from any context.
232 */
233 printk(KERN_WARNING "zio pool=%s vdev=%s error=%d type=%d "
234 "offset=%llu size=%llu flags=%llu\n", spa_name(zio->io_spa),
235 zio->io_vd->vdev_path, zio->io_error, zio->io_type,
236 (u_longlong_t)zio->io_offset, (u_longlong_t)zio->io_size,
237 zio->io_flags);
238 }
239
240 static void
vdev_disk_kobj_evt_post(vdev_t * v)241 vdev_disk_kobj_evt_post(vdev_t *v)
242 {
243 vdev_disk_t *vd = v->vdev_tsd;
244 if (vd && vd->vd_bdh) {
245 spl_signal_kobj_evt(BDH_BDEV(vd->vd_bdh));
246 } else {
247 vdev_dbgmsg(v, "vdev_disk_t is NULL for VDEV:%s\n",
248 v->vdev_path);
249 }
250 }
251
252 static zfs_bdev_handle_t *
vdev_blkdev_get_by_path(const char * path,spa_mode_t smode,void * holder)253 vdev_blkdev_get_by_path(const char *path, spa_mode_t smode, void *holder)
254 {
255 vdev_bdev_mode_t bmode = vdev_bdev_mode(smode);
256
257 #if defined(HAVE_BDEV_FILE_OPEN_BY_PATH)
258 return (bdev_file_open_by_path(path, bmode, holder, NULL));
259 #elif defined(HAVE_BDEV_OPEN_BY_PATH)
260 return (bdev_open_by_path(path, bmode, holder, NULL));
261 #elif defined(HAVE_BLKDEV_GET_BY_PATH_4ARG)
262 return (blkdev_get_by_path(path, bmode, holder, NULL));
263 #else
264 return (blkdev_get_by_path(path, bmode, holder));
265 #endif
266 }
267
268 static void
vdev_blkdev_put(zfs_bdev_handle_t * bdh,spa_mode_t smode,void * holder)269 vdev_blkdev_put(zfs_bdev_handle_t *bdh, spa_mode_t smode, void *holder)
270 {
271 #if defined(HAVE_BDEV_RELEASE)
272 return (bdev_release(bdh));
273 #elif defined(HAVE_BLKDEV_PUT_HOLDER)
274 return (blkdev_put(BDH_BDEV(bdh), holder));
275 #elif defined(HAVE_BLKDEV_PUT)
276 return (blkdev_put(BDH_BDEV(bdh), vdev_bdev_mode(smode)));
277 #else
278 fput(bdh);
279 #endif
280 }
281
282 static int
vdev_disk_open(vdev_t * v,uint64_t * psize,uint64_t * max_psize,uint64_t * logical_ashift,uint64_t * physical_ashift)283 vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
284 uint64_t *logical_ashift, uint64_t *physical_ashift)
285 {
286 zfs_bdev_handle_t *bdh;
287 spa_mode_t smode = spa_mode(v->vdev_spa);
288 hrtime_t timeout = MSEC2NSEC(zfs_vdev_open_timeout_ms);
289 vdev_disk_t *vd;
290
291 /* Must have a pathname and it must be absolute. */
292 if (v->vdev_path == NULL || v->vdev_path[0] != '/') {
293 v->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
294 vdev_dbgmsg(v, "invalid vdev_path");
295 return (SET_ERROR(EINVAL));
296 }
297
298 /*
299 * Reopen the device if it is currently open. When expanding a
300 * partition force re-scanning the partition table if userland
301 * did not take care of this already. We need to do this while closed
302 * in order to get an accurate updated block device size. Then
303 * since udev may need to recreate the device links increase the
304 * open retry timeout before reporting the device as unavailable.
305 */
306 vd = v->vdev_tsd;
307 if (vd) {
308 char disk_name[BDEVNAME_SIZE + 6] = "/dev/";
309 boolean_t reread_part = B_FALSE;
310
311 rw_enter(&vd->vd_lock, RW_WRITER);
312 bdh = vd->vd_bdh;
313 vd->vd_bdh = NULL;
314
315 if (bdh) {
316 struct block_device *bdev = BDH_BDEV(bdh);
317 if (v->vdev_expanding && bdev != bdev_whole(bdev)) {
318 vdev_bdevname(bdev_whole(bdev), disk_name + 5);
319 /*
320 * If userland has BLKPG_RESIZE_PARTITION,
321 * then it should have updated the partition
322 * table already. We can detect this by
323 * comparing our current physical size
324 * with that of the device. If they are
325 * the same, then we must not have
326 * BLKPG_RESIZE_PARTITION or it failed to
327 * update the partition table online. We
328 * fallback to rescanning the partition
329 * table from the kernel below. However,
330 * if the capacity already reflects the
331 * updated partition, then we skip
332 * rescanning the partition table here.
333 */
334 if (v->vdev_psize == bdev_capacity(bdev))
335 reread_part = B_TRUE;
336 }
337
338 vdev_blkdev_put(bdh, smode, zfs_vdev_holder);
339 }
340
341 if (reread_part) {
342 bdh = vdev_blkdev_get_by_path(disk_name, smode,
343 zfs_vdev_holder);
344 if (!BDH_IS_ERR(bdh)) {
345 int error =
346 vdev_bdev_reread_part(BDH_BDEV(bdh));
347 vdev_blkdev_put(bdh, smode, zfs_vdev_holder);
348 if (error == 0) {
349 timeout = MSEC2NSEC(
350 zfs_vdev_open_timeout_ms * 2);
351 }
352 }
353 }
354 } else {
355 vd = kmem_zalloc(sizeof (vdev_disk_t), KM_SLEEP);
356
357 rw_init(&vd->vd_lock, NULL, RW_DEFAULT, NULL);
358 rw_enter(&vd->vd_lock, RW_WRITER);
359 }
360
361 /*
362 * Devices are always opened by the path provided at configuration
363 * time. This means that if the provided path is a udev by-id path
364 * then drives may be re-cabled without an issue. If the provided
365 * path is a udev by-path path, then the physical location information
366 * will be preserved. This can be critical for more complicated
367 * configurations where drives are located in specific physical
368 * locations to maximize the systems tolerance to component failure.
369 *
370 * Alternatively, you can provide your own udev rule to flexibly map
371 * the drives as you see fit. It is not advised that you use the
372 * /dev/[hd]d devices which may be reordered due to probing order.
373 * Devices in the wrong locations will be detected by the higher
374 * level vdev validation.
375 *
376 * The specified paths may be briefly removed and recreated in
377 * response to udev events. This should be exceptionally unlikely
378 * because the zpool command makes every effort to verify these paths
379 * have already settled prior to reaching this point. Therefore,
380 * a ENOENT failure at this point is highly likely to be transient
381 * and it is reasonable to sleep and retry before giving up. In
382 * practice delays have been observed to be on the order of 100ms.
383 *
384 * When ERESTARTSYS is returned it indicates the block device is
385 * a zvol which could not be opened due to the deadlock detection
386 * logic in zvol_open(). Extend the timeout and retry the open
387 * subsequent attempts are expected to eventually succeed.
388 */
389 hrtime_t start = gethrtime();
390 bdh = BDH_ERR_PTR(-ENXIO);
391 while (BDH_IS_ERR(bdh) && ((gethrtime() - start) < timeout)) {
392 bdh = vdev_blkdev_get_by_path(v->vdev_path, smode,
393 zfs_vdev_holder);
394 if (unlikely(BDH_PTR_ERR(bdh) == -ENOENT)) {
395 /*
396 * There is no point of waiting since device is removed
397 * explicitly
398 */
399 if (v->vdev_removed)
400 break;
401
402 schedule_timeout_interruptible(MSEC_TO_TICK(10));
403 } else if (unlikely(BDH_PTR_ERR(bdh) == -ERESTARTSYS)) {
404 timeout = MSEC2NSEC(zfs_vdev_open_timeout_ms * 10);
405 continue;
406 } else if (BDH_IS_ERR(bdh)) {
407 break;
408 }
409 }
410
411 if (BDH_IS_ERR(bdh)) {
412 int error = -BDH_PTR_ERR(bdh);
413 vdev_dbgmsg(v, "open error=%d timeout=%llu/%llu", error,
414 (u_longlong_t)(gethrtime() - start),
415 (u_longlong_t)timeout);
416 vd->vd_bdh = NULL;
417 v->vdev_tsd = vd;
418 rw_exit(&vd->vd_lock);
419 return (SET_ERROR(error));
420 } else {
421 vd->vd_bdh = bdh;
422 v->vdev_tsd = vd;
423 rw_exit(&vd->vd_lock);
424 }
425
426 struct block_device *bdev = BDH_BDEV(vd->vd_bdh);
427
428 /* Determine the physical block size */
429 int physical_block_size = bdev_physical_block_size(bdev);
430
431 /* Determine the logical block size */
432 int logical_block_size = bdev_logical_block_size(bdev);
433
434 /*
435 * If the device has a write cache, clear the nowritecache flag,
436 * so that we start issuing flush requests again.
437 */
438 v->vdev_nowritecache = !zfs_bdev_has_write_cache(bdev);
439
440 /* Set when device reports it supports TRIM. */
441 v->vdev_has_trim = bdev_discard_supported(bdev);
442
443 /* Set when device reports it supports secure TRIM. */
444 v->vdev_has_securetrim = bdev_secure_discard_supported(bdev);
445
446 /* Inform the ZIO pipeline that we are non-rotational */
447 v->vdev_nonrot = blk_queue_nonrot(bdev_get_queue(bdev));
448
449 /* Physical volume size in bytes for the partition */
450 *psize = bdev_capacity(bdev);
451
452 /* Physical volume size in bytes including possible expansion space */
453 *max_psize = bdev_max_capacity(bdev, v->vdev_wholedisk);
454
455 /* Based on the minimum sector size set the block size */
456 *physical_ashift = highbit64(MAX(physical_block_size,
457 SPA_MINBLOCKSIZE)) - 1;
458
459 *logical_ashift = highbit64(MAX(logical_block_size,
460 SPA_MINBLOCKSIZE)) - 1;
461
462 return (0);
463 }
464
465 static void
vdev_disk_close(vdev_t * v)466 vdev_disk_close(vdev_t *v)
467 {
468 vdev_disk_t *vd = v->vdev_tsd;
469
470 if (v->vdev_reopening || vd == NULL)
471 return;
472
473 if (vd->vd_bdh != NULL)
474 vdev_blkdev_put(vd->vd_bdh, spa_mode(v->vdev_spa),
475 zfs_vdev_holder);
476
477 rw_destroy(&vd->vd_lock);
478 kmem_free(vd, sizeof (vdev_disk_t));
479 v->vdev_tsd = NULL;
480 }
481
482 /*
483 * preempt_schedule_notrace is GPL-only which breaks the ZFS build, so
484 * replace it with preempt_schedule under the following condition:
485 */
486 #if defined(CONFIG_ARM64) && \
487 defined(CONFIG_PREEMPTION) && \
488 defined(CONFIG_BLK_CGROUP)
489 #define preempt_schedule_notrace(x) preempt_schedule(x)
490 #endif
491
492 /*
493 * As for the Linux 5.18 kernel bio_alloc() expects a block_device struct
494 * as an argument removing the need to set it with bio_set_dev(). This
495 * removes the need for all of the following compatibility code.
496 */
497 #if !defined(HAVE_BIO_ALLOC_4ARG)
498
499 #if defined(CONFIG_BLK_CGROUP) && defined(HAVE_BIO_SET_DEV_GPL_ONLY)
500 /*
501 * The Linux 5.5 kernel updated percpu_ref_tryget() which is inlined by
502 * blkg_tryget() to use rcu_read_lock() instead of rcu_read_lock_sched().
503 * As a side effect the function was converted to GPL-only. Define our
504 * own version when needed which uses rcu_read_lock_sched().
505 *
506 * The Linux 5.17 kernel split linux/blk-cgroup.h into a private and a public
507 * part, moving blkg_tryget into the private one. Define our own version.
508 */
509 #if defined(HAVE_BLKG_TRYGET_GPL_ONLY) || !defined(HAVE_BLKG_TRYGET)
510 static inline bool
vdev_blkg_tryget(struct blkcg_gq * blkg)511 vdev_blkg_tryget(struct blkcg_gq *blkg)
512 {
513 struct percpu_ref *ref = &blkg->refcnt;
514 unsigned long __percpu *count;
515 bool rc;
516
517 rcu_read_lock_sched();
518
519 if (__ref_is_percpu(ref, &count)) {
520 this_cpu_inc(*count);
521 rc = true;
522 } else {
523 #ifdef ZFS_PERCPU_REF_COUNT_IN_DATA
524 rc = atomic_long_inc_not_zero(&ref->data->count);
525 #else
526 rc = atomic_long_inc_not_zero(&ref->count);
527 #endif
528 }
529
530 rcu_read_unlock_sched();
531
532 return (rc);
533 }
534 #else
535 #define vdev_blkg_tryget(bg) blkg_tryget(bg)
536 #endif
537 #ifdef HAVE_BIO_SET_DEV_MACRO
538 /*
539 * The Linux 5.0 kernel updated the bio_set_dev() macro so it calls the
540 * GPL-only bio_associate_blkg() symbol thus inadvertently converting
541 * the entire macro. Provide a minimal version which always assigns the
542 * request queue's root_blkg to the bio.
543 */
544 static inline void
vdev_bio_associate_blkg(struct bio * bio)545 vdev_bio_associate_blkg(struct bio *bio)
546 {
547 #if defined(HAVE_BIO_BDEV_DISK)
548 struct request_queue *q = bio->bi_bdev->bd_disk->queue;
549 #else
550 struct request_queue *q = bio->bi_disk->queue;
551 #endif
552
553 ASSERT3P(q, !=, NULL);
554 ASSERT3P(bio->bi_blkg, ==, NULL);
555
556 if (q->root_blkg && vdev_blkg_tryget(q->root_blkg))
557 bio->bi_blkg = q->root_blkg;
558 }
559
560 #define bio_associate_blkg vdev_bio_associate_blkg
561 #else
562 static inline void
vdev_bio_set_dev(struct bio * bio,struct block_device * bdev)563 vdev_bio_set_dev(struct bio *bio, struct block_device *bdev)
564 {
565 #if defined(HAVE_BIO_BDEV_DISK)
566 struct request_queue *q = bdev->bd_disk->queue;
567 #else
568 struct request_queue *q = bio->bi_disk->queue;
569 #endif
570 bio_clear_flag(bio, BIO_REMAPPED);
571 if (bio->bi_bdev != bdev)
572 bio_clear_flag(bio, BIO_THROTTLED);
573 bio->bi_bdev = bdev;
574
575 ASSERT3P(q, !=, NULL);
576 ASSERT3P(bio->bi_blkg, ==, NULL);
577
578 if (q->root_blkg && vdev_blkg_tryget(q->root_blkg))
579 bio->bi_blkg = q->root_blkg;
580 }
581 #define bio_set_dev vdev_bio_set_dev
582 #endif
583 #endif
584 #endif /* !HAVE_BIO_ALLOC_4ARG */
585
586 static inline void
vdev_submit_bio(struct bio * bio)587 vdev_submit_bio(struct bio *bio)
588 {
589 struct bio_list *bio_list = current->bio_list;
590 current->bio_list = NULL;
591 (void) submit_bio(bio);
592 current->bio_list = bio_list;
593 }
594
595 static inline struct bio *
vdev_bio_alloc(struct block_device * bdev,gfp_t gfp_mask,unsigned short nr_vecs)596 vdev_bio_alloc(struct block_device *bdev, gfp_t gfp_mask,
597 unsigned short nr_vecs)
598 {
599 struct bio *bio;
600
601 #ifdef HAVE_BIO_ALLOC_4ARG
602 bio = bio_alloc(bdev, nr_vecs, 0, gfp_mask);
603 #else
604 bio = bio_alloc(gfp_mask, nr_vecs);
605 if (likely(bio != NULL))
606 bio_set_dev(bio, bdev);
607 #endif
608
609 return (bio);
610 }
611
612 static inline uint_t
vdev_bio_max_segs(struct block_device * bdev)613 vdev_bio_max_segs(struct block_device *bdev)
614 {
615 /*
616 * Smallest of the device max segs and the tuneable max segs. Minimum
617 * 4, so there's room to finish split pages if they come up.
618 */
619 const uint_t dev_max_segs = queue_max_segments(bdev_get_queue(bdev));
620 const uint_t tune_max_segs = (zfs_vdev_disk_max_segs > 0) ?
621 MAX(4, zfs_vdev_disk_max_segs) : dev_max_segs;
622 const uint_t max_segs = MIN(tune_max_segs, dev_max_segs);
623
624 #ifdef HAVE_BIO_MAX_SEGS
625 return (bio_max_segs(max_segs));
626 #else
627 return (MIN(max_segs, BIO_MAX_PAGES));
628 #endif
629 }
630
631 static inline uint_t
vdev_bio_max_bytes(struct block_device * bdev)632 vdev_bio_max_bytes(struct block_device *bdev)
633 {
634 return (queue_max_sectors(bdev_get_queue(bdev)) << 9);
635 }
636
637
638 /*
639 * Virtual block IO object (VBIO)
640 *
641 * Linux block IO (BIO) objects have a limit on how many data segments (pages)
642 * they can hold. Depending on how they're allocated and structured, a large
643 * ZIO can require more than one BIO to be submitted to the kernel, which then
644 * all have to complete before we can return the completed ZIO back to ZFS.
645 *
646 * A VBIO is a wrapper around multiple BIOs, carrying everything needed to
647 * translate a ZIO down into the kernel block layer and back again.
648 *
649 * Note that these are only used for data ZIOs (read/write). Meta-operations
650 * (flush/trim) don't need multiple BIOs and so can just make the call
651 * directly.
652 */
653 typedef struct {
654 zio_t *vbio_zio; /* parent zio */
655
656 struct block_device *vbio_bdev; /* blockdev to submit bios to */
657
658 abd_t *vbio_abd; /* abd carrying borrowed linear buf */
659
660 uint_t vbio_max_segs; /* max segs per bio */
661
662 uint_t vbio_max_bytes; /* max bytes per bio */
663 uint_t vbio_lbs_mask; /* logical block size mask */
664
665 uint64_t vbio_offset; /* start offset of next bio */
666
667 struct bio *vbio_bio; /* pointer to the current bio */
668 int vbio_flags; /* bio flags */
669 } vbio_t;
670
671 static vbio_t *
vbio_alloc(zio_t * zio,struct block_device * bdev,int flags)672 vbio_alloc(zio_t *zio, struct block_device *bdev, int flags)
673 {
674 vbio_t *vbio = kmem_zalloc(sizeof (vbio_t), KM_SLEEP);
675
676 vbio->vbio_zio = zio;
677 vbio->vbio_bdev = bdev;
678 vbio->vbio_abd = NULL;
679 vbio->vbio_max_segs = vdev_bio_max_segs(bdev);
680 vbio->vbio_max_bytes = vdev_bio_max_bytes(bdev);
681 vbio->vbio_lbs_mask = ~(bdev_logical_block_size(bdev)-1);
682 vbio->vbio_offset = zio->io_offset;
683 vbio->vbio_bio = NULL;
684 vbio->vbio_flags = flags;
685
686 return (vbio);
687 }
688
689 static void vbio_completion(struct bio *bio);
690
691 static int
vbio_add_page(vbio_t * vbio,struct page * page,uint_t size,uint_t offset)692 vbio_add_page(vbio_t *vbio, struct page *page, uint_t size, uint_t offset)
693 {
694 struct bio *bio = vbio->vbio_bio;
695 uint_t ssize;
696
697 while (size > 0) {
698 if (bio == NULL) {
699 /* New BIO, allocate and set up */
700 bio = vdev_bio_alloc(vbio->vbio_bdev, GFP_NOIO,
701 vbio->vbio_max_segs);
702 VERIFY(bio);
703
704 BIO_BI_SECTOR(bio) = vbio->vbio_offset >> 9;
705 bio_set_op_attrs(bio,
706 vbio->vbio_zio->io_type == ZIO_TYPE_WRITE ?
707 WRITE : READ, vbio->vbio_flags);
708
709 if (vbio->vbio_bio) {
710 bio_chain(vbio->vbio_bio, bio);
711 vdev_submit_bio(vbio->vbio_bio);
712 }
713 vbio->vbio_bio = bio;
714 }
715
716 /*
717 * Only load as much of the current page data as will fit in
718 * the space left in the BIO, respecting lbs alignment. Older
719 * kernels will error if we try to overfill the BIO, while
720 * newer ones will accept it and split the BIO. This ensures
721 * everything works on older kernels, and avoids an additional
722 * overhead on the new.
723 */
724 ssize = MIN(size, (vbio->vbio_max_bytes - BIO_BI_SIZE(bio)) &
725 vbio->vbio_lbs_mask);
726 if (ssize > 0 &&
727 bio_add_page(bio, page, ssize, offset) == ssize) {
728 /* Accepted, adjust and load any remaining. */
729 size -= ssize;
730 offset += ssize;
731 continue;
732 }
733
734 /* No room, set up for a new BIO and loop */
735 vbio->vbio_offset += BIO_BI_SIZE(bio);
736
737 /* Signal new BIO allocation wanted */
738 bio = NULL;
739 }
740
741 return (0);
742 }
743
744 /* Iterator callback to submit ABD pages to the vbio. */
745 static int
vbio_fill_cb(struct page * page,size_t off,size_t len,void * priv)746 vbio_fill_cb(struct page *page, size_t off, size_t len, void *priv)
747 {
748 vbio_t *vbio = priv;
749 return (vbio_add_page(vbio, page, len, off));
750 }
751
752 /* Create some BIOs, fill them with data and submit them */
753 static void
vbio_submit(vbio_t * vbio,abd_t * abd,uint64_t size)754 vbio_submit(vbio_t *vbio, abd_t *abd, uint64_t size)
755 {
756 /*
757 * We plug so we can submit the BIOs as we go and only unplug them when
758 * they are fully created and submitted. This is important; if we don't
759 * plug, then the kernel may start executing earlier BIOs while we're
760 * still creating and executing later ones, and if the device goes
761 * away while that's happening, older kernels can get confused and
762 * trample memory.
763 */
764 struct blk_plug plug;
765 blk_start_plug(&plug);
766
767 (void) abd_iterate_page_func(abd, 0, size, vbio_fill_cb, vbio);
768 ASSERT(vbio->vbio_bio);
769
770 vbio->vbio_bio->bi_end_io = vbio_completion;
771 vbio->vbio_bio->bi_private = vbio;
772
773 /*
774 * Once submitted, vbio_bio now owns vbio (through bi_private) and we
775 * can't touch it again. The bio may complete and vbio_completion() be
776 * called and free the vbio before this task is run again, so we must
777 * consider it invalid from this point.
778 */
779 vdev_submit_bio(vbio->vbio_bio);
780
781 blk_finish_plug(&plug);
782 }
783
784 /* IO completion callback */
785 static void
vbio_completion(struct bio * bio)786 vbio_completion(struct bio *bio)
787 {
788 vbio_t *vbio = bio->bi_private;
789 zio_t *zio = vbio->vbio_zio;
790
791 ASSERT(zio);
792
793 /* Capture and log any errors */
794 zio->io_error = bi_status_to_errno(bio->bi_status);
795 ASSERT3U(zio->io_error, >=, 0);
796
797 if (zio->io_error)
798 vdev_disk_error(zio);
799
800 /* Return the BIO to the kernel */
801 bio_put(bio);
802
803 /*
804 * We're likely in an interrupt context so we can't do ABD/memory work
805 * here; instead we stash vbio on the zio and take care of it in the
806 * done callback.
807 */
808 ASSERT3P(zio->io_bio, ==, NULL);
809 zio->io_bio = vbio;
810
811 zio_delay_interrupt(zio);
812 }
813
814 /*
815 * Iterator callback to count ABD pages and check their size & alignment.
816 *
817 * On Linux, each BIO segment can take a page pointer, and an offset+length of
818 * the data within that page. A page can be arbitrarily large ("compound"
819 * pages) but we still have to ensure the data portion is correctly sized and
820 * aligned to the logical block size, to ensure that if the kernel wants to
821 * split the BIO, the two halves will still be properly aligned.
822 *
823 * NOTE: if you change this function, change the copy in
824 * tests/zfs-tests/tests/functional/vdev_disk/page_alignment.c, and add test
825 * data there to validate the change you're making.
826 */
827 typedef struct {
828 size_t blocksize;
829 int seen_first;
830 int seen_last;
831 } vdev_disk_check_alignment_t;
832
833 static int
vdev_disk_check_alignment_cb(struct page * page,size_t off,size_t len,void * priv)834 vdev_disk_check_alignment_cb(struct page *page, size_t off, size_t len,
835 void *priv)
836 {
837 (void) page;
838 vdev_disk_check_alignment_t *s = priv;
839
840 /*
841 * The cardinal rule: a single on-disk block must never cross an
842 * physical (order-0) page boundary, as the kernel expects to be able
843 * to split at both LBS and page boundaries.
844 *
845 * This implies various alignment rules for the blocks in this
846 * (possibly compound) page, which we can check for.
847 */
848
849 /*
850 * If the previous page did not end on a page boundary, then we
851 * can't proceed without creating a hole.
852 */
853 if (s->seen_last)
854 return (1);
855
856 /* This page must contain only whole LBS-sized blocks. */
857 if (!IS_P2ALIGNED(len, s->blocksize))
858 return (1);
859
860 /*
861 * If this is not the first page in the ABD, then the data must start
862 * on a page-aligned boundary (so the kernel can split on page
863 * boundaries without having to deal with a hole). If it is, then
864 * it can start on LBS-alignment.
865 */
866 if (s->seen_first) {
867 if (!IS_P2ALIGNED(off, PAGESIZE))
868 return (1);
869 } else {
870 if (!IS_P2ALIGNED(off, s->blocksize))
871 return (1);
872 s->seen_first = 1;
873 }
874
875 /*
876 * If this data does not end on a page-aligned boundary, then this
877 * must be the last page in the ABD, for the same reason.
878 */
879 s->seen_last = !IS_P2ALIGNED(off+len, PAGESIZE);
880
881 return (0);
882 }
883
884 /*
885 * Check if we can submit the pages in this ABD to the kernel as-is. Returns
886 * the number of pages, or 0 if it can't be submitted like this.
887 */
888 static boolean_t
vdev_disk_check_alignment(abd_t * abd,uint64_t size,struct block_device * bdev)889 vdev_disk_check_alignment(abd_t *abd, uint64_t size, struct block_device *bdev)
890 {
891 vdev_disk_check_alignment_t s = {
892 .blocksize = bdev_logical_block_size(bdev),
893 };
894
895 if (abd_iterate_page_func(abd, 0, size,
896 vdev_disk_check_alignment_cb, &s))
897 return (B_FALSE);
898
899 return (B_TRUE);
900 }
901
902 static int
vdev_disk_io_rw(zio_t * zio)903 vdev_disk_io_rw(zio_t *zio)
904 {
905 vdev_t *v = zio->io_vd;
906 vdev_disk_t *vd = v->vdev_tsd;
907 struct block_device *bdev = BDH_BDEV(vd->vd_bdh);
908 int flags = 0;
909
910 /*
911 * Accessing outside the block device is never allowed.
912 */
913 if (zio->io_offset + zio->io_size > bdev_capacity(bdev)) {
914 vdev_dbgmsg(zio->io_vd,
915 "Illegal access %llu size %llu, device size %llu",
916 (u_longlong_t)zio->io_offset,
917 (u_longlong_t)zio->io_size,
918 (u_longlong_t)bdev_capacity(bdev));
919 return (SET_ERROR(EIO));
920 }
921
922 if (!(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)) &&
923 v->vdev_failfast == B_TRUE) {
924 bio_set_flags_failfast(bdev, &flags, zfs_vdev_failfast_mask & 1,
925 zfs_vdev_failfast_mask & 2, zfs_vdev_failfast_mask & 4);
926 }
927
928 /*
929 * Check alignment of the incoming ABD. If any part of it would require
930 * submitting a page that is not aligned to both the logical block size
931 * and the page size, then we take a copy into a new memory region with
932 * correct alignment. This should be impossible on a 512b LBS. On
933 * larger blocks, this can happen at least when a small number of
934 * blocks (usually 1) are allocated from a shared slab, or when
935 * abnormally-small data regions (eg gang headers) are mixed into the
936 * same ABD as larger allocations (eg aggregations).
937 */
938 abd_t *abd = zio->io_abd;
939 if (!vdev_disk_check_alignment(abd, zio->io_size, bdev)) {
940 /* Allocate a new memory region with guaranteed alignment */
941 abd = abd_alloc_for_io(zio->io_size,
942 zio->io_abd->abd_flags & ABD_FLAG_META);
943
944 /* If we're writing copy our data into it */
945 if (zio->io_type == ZIO_TYPE_WRITE)
946 abd_copy(abd, zio->io_abd, zio->io_size);
947
948 /*
949 * False here would mean the new allocation has an invalid
950 * alignment too, which would mean that abd_alloc() is not
951 * guaranteeing this, or our logic in
952 * vdev_disk_check_alignment() is wrong. In either case,
953 * something in seriously wrong and its not safe to continue.
954 */
955 VERIFY(vdev_disk_check_alignment(abd, zio->io_size, bdev));
956 }
957
958 /* Allocate vbio, with a pointer to the borrowed ABD if necessary */
959 vbio_t *vbio = vbio_alloc(zio, bdev, flags);
960 if (abd != zio->io_abd)
961 vbio->vbio_abd = abd;
962
963 /* Fill it with data pages and submit it to the kernel */
964 vbio_submit(vbio, abd, zio->io_size);
965 return (0);
966 }
967
968 /* ========== */
969
970 /*
971 * This is the classic, battle-tested BIO submission code. Until we're totally
972 * sure that the new code is safe and correct in all cases, this will remain
973 * available and can be enabled by setting zfs_vdev_disk_classic=1 at module
974 * load time.
975 *
976 * These functions have been renamed to vdev_classic_* to make it clear what
977 * they belong to, but their implementations are unchanged.
978 */
979
980 /*
981 * Virtual device vector for disks.
982 */
983 typedef struct dio_request {
984 zio_t *dr_zio; /* Parent ZIO */
985 atomic_t dr_ref; /* References */
986 int dr_error; /* Bio error */
987 int dr_bio_count; /* Count of bio's */
988 struct bio *dr_bio[]; /* Attached bio's */
989 } dio_request_t;
990
991 static dio_request_t *
vdev_classic_dio_alloc(int bio_count)992 vdev_classic_dio_alloc(int bio_count)
993 {
994 dio_request_t *dr = kmem_zalloc(sizeof (dio_request_t) +
995 sizeof (struct bio *) * bio_count, KM_SLEEP);
996 atomic_set(&dr->dr_ref, 0);
997 dr->dr_bio_count = bio_count;
998 dr->dr_error = 0;
999
1000 for (int i = 0; i < dr->dr_bio_count; i++)
1001 dr->dr_bio[i] = NULL;
1002
1003 return (dr);
1004 }
1005
1006 static void
vdev_classic_dio_free(dio_request_t * dr)1007 vdev_classic_dio_free(dio_request_t *dr)
1008 {
1009 int i;
1010
1011 for (i = 0; i < dr->dr_bio_count; i++)
1012 if (dr->dr_bio[i])
1013 bio_put(dr->dr_bio[i]);
1014
1015 kmem_free(dr, sizeof (dio_request_t) +
1016 sizeof (struct bio *) * dr->dr_bio_count);
1017 }
1018
1019 static void
vdev_classic_dio_get(dio_request_t * dr)1020 vdev_classic_dio_get(dio_request_t *dr)
1021 {
1022 atomic_inc(&dr->dr_ref);
1023 }
1024
1025 static void
vdev_classic_dio_put(dio_request_t * dr)1026 vdev_classic_dio_put(dio_request_t *dr)
1027 {
1028 int rc = atomic_dec_return(&dr->dr_ref);
1029
1030 /*
1031 * Free the dio_request when the last reference is dropped and
1032 * ensure zio_interpret is called only once with the correct zio
1033 */
1034 if (rc == 0) {
1035 zio_t *zio = dr->dr_zio;
1036 int error = dr->dr_error;
1037
1038 vdev_classic_dio_free(dr);
1039
1040 if (zio) {
1041 zio->io_error = error;
1042 ASSERT3S(zio->io_error, >=, 0);
1043 if (zio->io_error)
1044 vdev_disk_error(zio);
1045
1046 zio_delay_interrupt(zio);
1047 }
1048 }
1049 }
1050
1051 static void
vdev_classic_physio_completion(struct bio * bio)1052 vdev_classic_physio_completion(struct bio *bio)
1053 {
1054 dio_request_t *dr = bio->bi_private;
1055
1056 if (dr->dr_error == 0) {
1057 dr->dr_error = bi_status_to_errno(bio->bi_status);
1058 }
1059
1060 /* Drop reference acquired by vdev_classic_physio */
1061 vdev_classic_dio_put(dr);
1062 }
1063
1064 static inline unsigned int
vdev_classic_bio_max_segs(zio_t * zio,int bio_size,uint64_t abd_offset)1065 vdev_classic_bio_max_segs(zio_t *zio, int bio_size, uint64_t abd_offset)
1066 {
1067 unsigned long nr_segs = abd_nr_pages_off(zio->io_abd,
1068 bio_size, abd_offset);
1069
1070 #ifdef HAVE_BIO_MAX_SEGS
1071 return (bio_max_segs(nr_segs));
1072 #else
1073 return (MIN(nr_segs, BIO_MAX_PAGES));
1074 #endif
1075 }
1076
1077 static int
vdev_classic_physio(zio_t * zio)1078 vdev_classic_physio(zio_t *zio)
1079 {
1080 vdev_t *v = zio->io_vd;
1081 vdev_disk_t *vd = v->vdev_tsd;
1082 struct block_device *bdev = BDH_BDEV(vd->vd_bdh);
1083 size_t io_size = zio->io_size;
1084 uint64_t io_offset = zio->io_offset;
1085 int rw = zio->io_type == ZIO_TYPE_READ ? READ : WRITE;
1086 int flags = 0;
1087
1088 dio_request_t *dr;
1089 uint64_t abd_offset;
1090 uint64_t bio_offset;
1091 int bio_size;
1092 int bio_count = 16;
1093 int error = 0;
1094 struct blk_plug plug;
1095 unsigned short nr_vecs;
1096
1097 /*
1098 * Accessing outside the block device is never allowed.
1099 */
1100 if (io_offset + io_size > bdev_capacity(bdev)) {
1101 vdev_dbgmsg(zio->io_vd,
1102 "Illegal access %llu size %llu, device size %llu",
1103 (u_longlong_t)io_offset,
1104 (u_longlong_t)io_size,
1105 (u_longlong_t)bdev_capacity(bdev));
1106 return (SET_ERROR(EIO));
1107 }
1108
1109 retry:
1110 dr = vdev_classic_dio_alloc(bio_count);
1111
1112 if (!(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)) &&
1113 zio->io_vd->vdev_failfast == B_TRUE) {
1114 bio_set_flags_failfast(bdev, &flags, zfs_vdev_failfast_mask & 1,
1115 zfs_vdev_failfast_mask & 2, zfs_vdev_failfast_mask & 4);
1116 }
1117
1118 dr->dr_zio = zio;
1119
1120 /*
1121 * Since bio's can have up to BIO_MAX_PAGES=256 iovec's, each of which
1122 * is at least 512 bytes and at most PAGESIZE (typically 4K), one bio
1123 * can cover at least 128KB and at most 1MB. When the required number
1124 * of iovec's exceeds this, we are forced to break the IO in multiple
1125 * bio's and wait for them all to complete. This is likely if the
1126 * recordsize property is increased beyond 1MB. The default
1127 * bio_count=16 should typically accommodate the maximum-size zio of
1128 * 16MB.
1129 */
1130
1131 abd_offset = 0;
1132 bio_offset = io_offset;
1133 bio_size = io_size;
1134 for (int i = 0; i <= dr->dr_bio_count; i++) {
1135
1136 /* Finished constructing bio's for given buffer */
1137 if (bio_size <= 0)
1138 break;
1139
1140 /*
1141 * If additional bio's are required, we have to retry, but
1142 * this should be rare - see the comment above.
1143 */
1144 if (dr->dr_bio_count == i) {
1145 vdev_classic_dio_free(dr);
1146 bio_count *= 2;
1147 goto retry;
1148 }
1149
1150 nr_vecs = vdev_classic_bio_max_segs(zio, bio_size, abd_offset);
1151 dr->dr_bio[i] = vdev_bio_alloc(bdev, GFP_NOIO, nr_vecs);
1152 if (unlikely(dr->dr_bio[i] == NULL)) {
1153 vdev_classic_dio_free(dr);
1154 return (SET_ERROR(ENOMEM));
1155 }
1156
1157 /* Matching put called by vdev_classic_physio_completion */
1158 vdev_classic_dio_get(dr);
1159
1160 BIO_BI_SECTOR(dr->dr_bio[i]) = bio_offset >> 9;
1161 dr->dr_bio[i]->bi_end_io = vdev_classic_physio_completion;
1162 dr->dr_bio[i]->bi_private = dr;
1163 bio_set_op_attrs(dr->dr_bio[i], rw, flags);
1164
1165 /* Remaining size is returned to become the new size */
1166 bio_size = abd_bio_map_off(dr->dr_bio[i], zio->io_abd,
1167 bio_size, abd_offset);
1168
1169 /* Advance in buffer and construct another bio if needed */
1170 abd_offset += BIO_BI_SIZE(dr->dr_bio[i]);
1171 bio_offset += BIO_BI_SIZE(dr->dr_bio[i]);
1172 }
1173
1174 /* Extra reference to protect dio_request during vdev_submit_bio */
1175 vdev_classic_dio_get(dr);
1176
1177 if (dr->dr_bio_count > 1)
1178 blk_start_plug(&plug);
1179
1180 /* Submit all bio's associated with this dio */
1181 for (int i = 0; i < dr->dr_bio_count; i++) {
1182 if (dr->dr_bio[i])
1183 vdev_submit_bio(dr->dr_bio[i]);
1184 }
1185
1186 if (dr->dr_bio_count > 1)
1187 blk_finish_plug(&plug);
1188
1189 vdev_classic_dio_put(dr);
1190
1191 return (error);
1192 }
1193
1194 /* ========== */
1195
1196 static void
vdev_disk_io_flush_completion(struct bio * bio)1197 vdev_disk_io_flush_completion(struct bio *bio)
1198 {
1199 zio_t *zio = bio->bi_private;
1200 zio->io_error = bi_status_to_errno(bio->bi_status);
1201
1202 if (zio->io_error && (zio->io_error == EOPNOTSUPP))
1203 zio->io_vd->vdev_nowritecache = B_TRUE;
1204
1205 bio_put(bio);
1206 ASSERT3S(zio->io_error, >=, 0);
1207 if (zio->io_error)
1208 vdev_disk_error(zio);
1209 zio_interrupt(zio);
1210 }
1211
1212 static int
vdev_disk_io_flush(struct block_device * bdev,zio_t * zio)1213 vdev_disk_io_flush(struct block_device *bdev, zio_t *zio)
1214 {
1215 struct request_queue *q;
1216 struct bio *bio;
1217
1218 q = bdev_get_queue(bdev);
1219 if (!q)
1220 return (SET_ERROR(ENXIO));
1221
1222 bio = vdev_bio_alloc(bdev, GFP_NOIO, 0);
1223 if (unlikely(bio == NULL))
1224 return (SET_ERROR(ENOMEM));
1225
1226 bio->bi_end_io = vdev_disk_io_flush_completion;
1227 bio->bi_private = zio;
1228 bio_set_flush(bio);
1229 vdev_submit_bio(bio);
1230 invalidate_bdev(bdev);
1231
1232 return (0);
1233 }
1234
1235 static void
vdev_disk_discard_end_io(struct bio * bio)1236 vdev_disk_discard_end_io(struct bio *bio)
1237 {
1238 zio_t *zio = bio->bi_private;
1239 zio->io_error = bi_status_to_errno(bio->bi_status);
1240
1241 bio_put(bio);
1242 if (zio->io_error)
1243 vdev_disk_error(zio);
1244 zio_interrupt(zio);
1245 }
1246
1247 /*
1248 * Wrappers for the different secure erase and discard APIs. We use async
1249 * when available; in this case, *biop is set to the last bio in the chain.
1250 */
1251 static int
vdev_bdev_issue_secure_erase(zfs_bdev_handle_t * bdh,sector_t sector,sector_t nsect,struct bio ** biop)1252 vdev_bdev_issue_secure_erase(zfs_bdev_handle_t *bdh, sector_t sector,
1253 sector_t nsect, struct bio **biop)
1254 {
1255 *biop = NULL;
1256 int error;
1257
1258 #if defined(HAVE_BLKDEV_ISSUE_SECURE_ERASE)
1259 error = blkdev_issue_secure_erase(BDH_BDEV(bdh),
1260 sector, nsect, GFP_NOFS);
1261 #elif defined(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_FLAGS)
1262 error = __blkdev_issue_discard(BDH_BDEV(bdh),
1263 sector, nsect, GFP_NOFS, BLKDEV_DISCARD_SECURE, biop);
1264 #elif defined(HAVE_BLKDEV_ISSUE_DISCARD_FLAGS)
1265 error = blkdev_issue_discard(BDH_BDEV(bdh),
1266 sector, nsect, GFP_NOFS, BLKDEV_DISCARD_SECURE);
1267 #else
1268 #error "unsupported kernel"
1269 #endif
1270
1271 return (error);
1272 }
1273
1274 static int
vdev_bdev_issue_discard(zfs_bdev_handle_t * bdh,sector_t sector,sector_t nsect,struct bio ** biop)1275 vdev_bdev_issue_discard(zfs_bdev_handle_t *bdh, sector_t sector,
1276 sector_t nsect, struct bio **biop)
1277 {
1278 *biop = NULL;
1279 int error;
1280
1281 #if defined(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_FLAGS)
1282 error = __blkdev_issue_discard(BDH_BDEV(bdh),
1283 sector, nsect, GFP_NOFS, 0, biop);
1284 #elif defined(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_NOFLAGS)
1285 error = __blkdev_issue_discard(BDH_BDEV(bdh),
1286 sector, nsect, GFP_NOFS, biop);
1287 #elif defined(HAVE_BLKDEV_ISSUE_DISCARD_FLAGS)
1288 error = blkdev_issue_discard(BDH_BDEV(bdh),
1289 sector, nsect, GFP_NOFS, 0);
1290 #elif defined(HAVE_BLKDEV_ISSUE_DISCARD_NOFLAGS)
1291 error = blkdev_issue_discard(BDH_BDEV(bdh),
1292 sector, nsect, GFP_NOFS);
1293 #else
1294 #error "unsupported kernel"
1295 #endif
1296
1297 return (error);
1298 }
1299
1300 /*
1301 * Entry point for TRIM ops. This calls the right wrapper for secure erase or
1302 * discard, and then does the appropriate finishing work for error vs success
1303 * and async vs sync.
1304 */
1305 static int
vdev_disk_io_trim(zio_t * zio)1306 vdev_disk_io_trim(zio_t *zio)
1307 {
1308 int error;
1309 struct bio *bio;
1310
1311 zfs_bdev_handle_t *bdh = ((vdev_disk_t *)zio->io_vd->vdev_tsd)->vd_bdh;
1312 sector_t sector = zio->io_offset >> 9;
1313 sector_t nsects = zio->io_size >> 9;
1314
1315 if (zio->io_trim_flags & ZIO_TRIM_SECURE)
1316 error = vdev_bdev_issue_secure_erase(bdh, sector, nsects, &bio);
1317 else
1318 error = vdev_bdev_issue_discard(bdh, sector, nsects, &bio);
1319
1320 if (error != 0)
1321 return (SET_ERROR(-error));
1322
1323 if (bio == NULL) {
1324 /*
1325 * This was a synchronous op that completed successfully, so
1326 * return it to ZFS immediately.
1327 */
1328 zio_interrupt(zio);
1329 } else {
1330 /*
1331 * This was an asynchronous op; set up completion callback and
1332 * issue it.
1333 */
1334 bio->bi_private = zio;
1335 bio->bi_end_io = vdev_disk_discard_end_io;
1336 vdev_submit_bio(bio);
1337 }
1338
1339 return (0);
1340 }
1341
1342 int (*vdev_disk_io_rw_fn)(zio_t *zio) = NULL;
1343
1344 static void
vdev_disk_io_start(zio_t * zio)1345 vdev_disk_io_start(zio_t *zio)
1346 {
1347 vdev_t *v = zio->io_vd;
1348 vdev_disk_t *vd = v->vdev_tsd;
1349 int error;
1350
1351 /*
1352 * If the vdev is closed, it's likely in the REMOVED or FAULTED state.
1353 * Nothing to be done here but return failure.
1354 */
1355 if (vd == NULL) {
1356 zio->io_error = ENXIO;
1357 zio_interrupt(zio);
1358 return;
1359 }
1360
1361 rw_enter(&vd->vd_lock, RW_READER);
1362
1363 /*
1364 * If the vdev is closed, it's likely due to a failed reopen and is
1365 * in the UNAVAIL state. Nothing to be done here but return failure.
1366 */
1367 if (vd->vd_bdh == NULL) {
1368 rw_exit(&vd->vd_lock);
1369 zio->io_error = ENXIO;
1370 zio_interrupt(zio);
1371 return;
1372 }
1373
1374 switch (zio->io_type) {
1375 case ZIO_TYPE_FLUSH:
1376
1377 if (!vdev_readable(v)) {
1378 /* Drive not there, can't flush */
1379 error = SET_ERROR(ENXIO);
1380 } else if (zfs_nocacheflush) {
1381 /* Flushing disabled by operator, declare success */
1382 error = 0;
1383 } else if (v->vdev_nowritecache) {
1384 /* This vdev not capable of flushing */
1385 error = SET_ERROR(ENOTSUP);
1386 } else {
1387 /*
1388 * Issue the flush. If successful, the response will
1389 * be handled in the completion callback, so we're done.
1390 */
1391 error = vdev_disk_io_flush(BDH_BDEV(vd->vd_bdh), zio);
1392 if (error == 0) {
1393 rw_exit(&vd->vd_lock);
1394 return;
1395 }
1396 }
1397
1398 /* Couldn't issue the flush, so set the error and return it */
1399 rw_exit(&vd->vd_lock);
1400 zio->io_error = error;
1401 zio_execute(zio);
1402 return;
1403
1404 case ZIO_TYPE_TRIM:
1405 error = vdev_disk_io_trim(zio);
1406 rw_exit(&vd->vd_lock);
1407 if (error) {
1408 zio->io_error = error;
1409 zio_execute(zio);
1410 }
1411 return;
1412
1413 case ZIO_TYPE_READ:
1414 case ZIO_TYPE_WRITE:
1415 zio->io_target_timestamp = zio_handle_io_delay(zio);
1416 error = vdev_disk_io_rw_fn(zio);
1417 rw_exit(&vd->vd_lock);
1418 if (error) {
1419 zio->io_error = error;
1420 zio_interrupt(zio);
1421 }
1422 return;
1423
1424 default:
1425 /*
1426 * Getting here means our parent vdev has made a very strange
1427 * request of us, and shouldn't happen. Assert here to force a
1428 * crash in dev builds, but in production return the IO
1429 * unhandled. The pool will likely suspend anyway but that's
1430 * nicer than crashing the kernel.
1431 */
1432 ASSERT3S(zio->io_type, ==, -1);
1433
1434 rw_exit(&vd->vd_lock);
1435 zio->io_error = SET_ERROR(ENOTSUP);
1436 zio_interrupt(zio);
1437 return;
1438 }
1439
1440 __builtin_unreachable();
1441 }
1442
1443 static void
vdev_disk_io_done(zio_t * zio)1444 vdev_disk_io_done(zio_t *zio)
1445 {
1446 /* If this was a read or write, we need to clean up the vbio */
1447 if (zio->io_bio != NULL) {
1448 vbio_t *vbio = zio->io_bio;
1449 zio->io_bio = NULL;
1450
1451 /*
1452 * If we copied the ABD before issuing it, clean up and return
1453 * the copy to the ADB, with changes if appropriate.
1454 */
1455 if (vbio->vbio_abd != NULL) {
1456 if (zio->io_type == ZIO_TYPE_READ)
1457 abd_copy(zio->io_abd, vbio->vbio_abd,
1458 zio->io_size);
1459
1460 abd_free(vbio->vbio_abd);
1461 vbio->vbio_abd = NULL;
1462 }
1463
1464 /* Final cleanup */
1465 kmem_free(vbio, sizeof (vbio_t));
1466 }
1467
1468 /*
1469 * If the device returned EIO, we revalidate the media. If it is
1470 * determined the media has changed this triggers the asynchronous
1471 * removal of the device from the configuration.
1472 */
1473 if (zio->io_error == EIO) {
1474 vdev_t *v = zio->io_vd;
1475 vdev_disk_t *vd = v->vdev_tsd;
1476
1477 if (!zfs_check_disk_status(BDH_BDEV(vd->vd_bdh))) {
1478 invalidate_bdev(BDH_BDEV(vd->vd_bdh));
1479 v->vdev_remove_wanted = B_TRUE;
1480 spa_async_request(zio->io_spa, SPA_ASYNC_REMOVE);
1481 }
1482 }
1483 }
1484
1485 static void
vdev_disk_hold(vdev_t * vd)1486 vdev_disk_hold(vdev_t *vd)
1487 {
1488 ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
1489
1490 /* We must have a pathname, and it must be absolute. */
1491 if (vd->vdev_path == NULL || vd->vdev_path[0] != '/')
1492 return;
1493
1494 /*
1495 * Only prefetch path and devid info if the device has
1496 * never been opened.
1497 */
1498 if (vd->vdev_tsd != NULL)
1499 return;
1500
1501 }
1502
1503 static void
vdev_disk_rele(vdev_t * vd)1504 vdev_disk_rele(vdev_t *vd)
1505 {
1506 ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
1507
1508 /* XXX: Implement me as a vnode rele for the device */
1509 }
1510
1511 /*
1512 * BIO submission method. See comment above about vdev_classic.
1513 * Set zfs_vdev_disk_classic=0 for new, =1 for classic
1514 */
1515 static uint_t zfs_vdev_disk_classic = 0; /* default new */
1516
1517 /* Set submission function from module parameter */
1518 static int
vdev_disk_param_set_classic(const char * buf,zfs_kernel_param_t * kp)1519 vdev_disk_param_set_classic(const char *buf, zfs_kernel_param_t *kp)
1520 {
1521 int err = param_set_uint(buf, kp);
1522 if (err < 0)
1523 return (SET_ERROR(err));
1524
1525 vdev_disk_io_rw_fn =
1526 zfs_vdev_disk_classic ? vdev_classic_physio : vdev_disk_io_rw;
1527
1528 printk(KERN_INFO "ZFS: forcing %s BIO submission\n",
1529 zfs_vdev_disk_classic ? "classic" : "new");
1530
1531 return (0);
1532 }
1533
1534 /*
1535 * At first use vdev use, set the submission function from the default value if
1536 * it hasn't been set already.
1537 */
1538 static int
vdev_disk_init(spa_t * spa,nvlist_t * nv,void ** tsd)1539 vdev_disk_init(spa_t *spa, nvlist_t *nv, void **tsd)
1540 {
1541 (void) spa;
1542 (void) nv;
1543 (void) tsd;
1544
1545 if (vdev_disk_io_rw_fn == NULL)
1546 vdev_disk_io_rw_fn = zfs_vdev_disk_classic ?
1547 vdev_classic_physio : vdev_disk_io_rw;
1548
1549 return (0);
1550 }
1551
1552 vdev_ops_t vdev_disk_ops = {
1553 .vdev_op_init = vdev_disk_init,
1554 .vdev_op_fini = NULL,
1555 .vdev_op_open = vdev_disk_open,
1556 .vdev_op_close = vdev_disk_close,
1557 .vdev_op_asize = vdev_default_asize,
1558 .vdev_op_min_asize = vdev_default_min_asize,
1559 .vdev_op_min_alloc = NULL,
1560 .vdev_op_io_start = vdev_disk_io_start,
1561 .vdev_op_io_done = vdev_disk_io_done,
1562 .vdev_op_state_change = NULL,
1563 .vdev_op_need_resilver = NULL,
1564 .vdev_op_hold = vdev_disk_hold,
1565 .vdev_op_rele = vdev_disk_rele,
1566 .vdev_op_remap = NULL,
1567 .vdev_op_xlate = vdev_default_xlate,
1568 .vdev_op_rebuild_asize = NULL,
1569 .vdev_op_metaslab_init = NULL,
1570 .vdev_op_config_generate = NULL,
1571 .vdev_op_nparity = NULL,
1572 .vdev_op_ndisks = NULL,
1573 .vdev_op_type = VDEV_TYPE_DISK, /* name of this vdev type */
1574 .vdev_op_leaf = B_TRUE, /* leaf vdev */
1575 .vdev_op_kobj_evt_post = vdev_disk_kobj_evt_post
1576 };
1577
1578 /*
1579 * The zfs_vdev_scheduler module option has been deprecated. Setting this
1580 * value no longer has any effect. It has not yet been entirely removed
1581 * to allow the module to be loaded if this option is specified in the
1582 * /etc/modprobe.d/zfs.conf file. The following warning will be logged.
1583 */
1584 static int
param_set_vdev_scheduler(const char * val,zfs_kernel_param_t * kp)1585 param_set_vdev_scheduler(const char *val, zfs_kernel_param_t *kp)
1586 {
1587 int error = param_set_charp(val, kp);
1588 if (error == 0) {
1589 printk(KERN_INFO "The 'zfs_vdev_scheduler' module option "
1590 "is not supported.\n");
1591 }
1592
1593 return (error);
1594 }
1595
1596 static const char *zfs_vdev_scheduler = "unused";
1597 module_param_call(zfs_vdev_scheduler, param_set_vdev_scheduler,
1598 param_get_charp, &zfs_vdev_scheduler, 0644);
1599 MODULE_PARM_DESC(zfs_vdev_scheduler, "I/O scheduler");
1600
1601 int
param_set_min_auto_ashift(const char * buf,zfs_kernel_param_t * kp)1602 param_set_min_auto_ashift(const char *buf, zfs_kernel_param_t *kp)
1603 {
1604 uint_t val;
1605 int error;
1606
1607 error = kstrtouint(buf, 0, &val);
1608 if (error < 0)
1609 return (SET_ERROR(error));
1610
1611 if (val < ASHIFT_MIN || val > zfs_vdev_max_auto_ashift)
1612 return (SET_ERROR(-EINVAL));
1613
1614 error = param_set_uint(buf, kp);
1615 if (error < 0)
1616 return (SET_ERROR(error));
1617
1618 return (0);
1619 }
1620
1621 int
param_set_max_auto_ashift(const char * buf,zfs_kernel_param_t * kp)1622 param_set_max_auto_ashift(const char *buf, zfs_kernel_param_t *kp)
1623 {
1624 uint_t val;
1625 int error;
1626
1627 error = kstrtouint(buf, 0, &val);
1628 if (error < 0)
1629 return (SET_ERROR(error));
1630
1631 if (val > ASHIFT_MAX || val < zfs_vdev_min_auto_ashift)
1632 return (SET_ERROR(-EINVAL));
1633
1634 error = param_set_uint(buf, kp);
1635 if (error < 0)
1636 return (SET_ERROR(error));
1637
1638 return (0);
1639 }
1640
1641 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, open_timeout_ms, UINT, ZMOD_RW,
1642 "Timeout before determining that a device is missing");
1643
1644 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, failfast_mask, UINT, ZMOD_RW,
1645 "Defines failfast mask: 1 - device, 2 - transport, 4 - driver");
1646
1647 ZFS_MODULE_PARAM(zfs_vdev_disk, zfs_vdev_disk_, max_segs, UINT, ZMOD_RW,
1648 "Maximum number of data segments to add to an IO request (min 4)");
1649
1650 ZFS_MODULE_PARAM_CALL(zfs_vdev_disk, zfs_vdev_disk_, classic,
1651 vdev_disk_param_set_classic, param_get_uint, ZMOD_RD,
1652 "Use classic BIO submission method");
1653