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.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
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]
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>.
28 #include <sys/zfs_context.h>
30 #include <sys/vdev_disk.h>
31 #include <sys/vdev_impl.h>
32 #include <sys/fs/zfs.h>
34 #include <sys/sunldi.h>
36 char *zfs_vdev_scheduler = VDEV_SCHEDULER;
39 * Virtual device vector for disks.
41 typedef struct dio_request {
42 struct completion dr_comp; /* Completion for sync IO */
43 atomic_t dr_ref; /* References */
44 zio_t *dr_zio; /* Parent ZIO */
45 int dr_rw; /* Read/Write */
46 int dr_error; /* Bio error */
47 int dr_bio_count; /* Count of bio's */
48 struct bio *dr_bio[0]; /* Attached bio's */
52 #ifdef HAVE_OPEN_BDEV_EXCLUSIVE
54 vdev_bdev_mode(int smode)
58 ASSERT3S(smode & (FREAD | FWRITE), !=, 0);
70 vdev_bdev_mode(int smode)
74 ASSERT3S(smode & (FREAD | FWRITE), !=, 0);
76 if ((smode & FREAD) && !(smode & FWRITE))
81 #endif /* HAVE_OPEN_BDEV_EXCLUSIVE */
84 bdev_capacity(struct block_device *bdev)
86 struct hd_struct *part = bdev->bd_part;
88 /* The partition capacity referenced by the block device */
90 return part->nr_sects;
92 /* Otherwise assume the full device capacity */
93 return get_capacity(bdev->bd_disk);
97 vdev_disk_error(zio_t *zio)
100 printk("ZFS: zio error=%d type=%d offset=%llu size=%llu "
101 "flags=%x delay=%llu\n", zio->io_error, zio->io_type,
102 (u_longlong_t)zio->io_offset, (u_longlong_t)zio->io_size,
103 zio->io_flags, (u_longlong_t)zio->io_delay);
108 * Use the Linux 'noop' elevator for zfs managed block devices. This
109 * strikes the ideal balance by allowing the zfs elevator to do all
110 * request ordering and prioritization. While allowing the Linux
111 * elevator to do the maximum front/back merging allowed by the
112 * physical device. This yields the largest possible requests for
113 * the device with the lowest total overhead.
115 * Unfortunately we cannot directly call the elevator_switch() function
116 * because it is not exported from the block layer. This means we have
117 * to use the sysfs interface and a user space upcall. Pools will be
118 * automatically imported on module load so we must do this at device
119 * open time from the kernel.
122 vdev_elevator_switch(vdev_t *v, char *elevator)
124 vdev_disk_t *vd = v->vdev_tsd;
125 struct block_device *bdev = vd->vd_bdev;
126 struct request_queue *q = bdev_get_queue(bdev);
127 char *device = bdev->bd_disk->disk_name;
128 char sh_path[] = "/bin/sh";
130 char *argv[] = { sh_path, "-c", sh_cmd };
131 char *envp[] = { NULL };
132 int count = 0, error;
134 /* Skip devices without schedulers (loop, ram, dm, etc) */
135 if (!q->elevator || !blk_queue_stackable(q))
138 /* Leave existing scheduler when set to "none" */
139 if (!strncmp(elevator, "none", 4) && (strlen(elevator) == 4))
143 * Set the desired scheduler with a three attempt retry for
144 * -EFAULT which has been observed to occur spuriously.
146 sprintf(sh_cmd, "%s \"%s\" >/sys/block/%s/queue/scheduler",
147 "/bin/echo", elevator, device);
149 while (++count <= 3) {
150 error = call_usermodehelper(sh_path, argv, envp, 1);
151 if ((error == 0) || (error != -EFAULT))
156 printk("ZFS: Unable to set \"%s\" scheduler for %s (%s): %d\n",
157 elevator, v->vdev_path, device, error);
163 vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *ashift)
165 struct block_device *bdev;
167 int mode, block_size;
169 /* Must have a pathname and it must be absolute. */
170 if (v->vdev_path == NULL || v->vdev_path[0] != '/') {
171 v->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
175 vd = kmem_zalloc(sizeof(vdev_disk_t), KM_SLEEP);
180 * Devices are always opened by the path provided at configuration
181 * time. This means that if the provided path is a udev by-id path
182 * then drives may be recabled without an issue. If the provided
183 * path is a udev by-path path then the physical location information
184 * will be preserved. This can be critical for more complicated
185 * configurations where drives are located in specific physical
186 * locations to maximize the systems tolerence to component failure.
187 * Alternately you can provide your own udev rule to flexibly map
188 * the drives as you see fit. It is not advised that you use the
189 * /dev/[hd]d devices which may be reorder due to probing order.
190 * Devices in the wrong locations will be detected by the higher
191 * level vdev validation.
193 mode = spa_mode(v->vdev_spa);
194 bdev = vdev_bdev_open(v->vdev_path, vdev_bdev_mode(mode), vd);
196 kmem_free(vd, sizeof(vdev_disk_t));
197 return -PTR_ERR(bdev);
202 block_size = vdev_bdev_block_size(bdev);
204 /* We think the wholedisk property should always be set when this
205 * function is called. ASSERT here so if any legitimate cases exist
206 * where it's not set, we'll find them during debugging. If we never
207 * hit the ASSERT, this and the following conditional statement can be
209 ASSERT3S(v->vdev_wholedisk, !=, -1ULL);
211 /* The wholedisk property was initialized to -1 in vdev_alloc() if it
212 * was unspecified. In that case, check if this is a whole device.
213 * When bdev->bd_contains == bdev we have a whole device and not simply
215 if (v->vdev_wholedisk == -1ULL)
216 v->vdev_wholedisk = (bdev->bd_contains == bdev);
218 /* Clear the nowritecache bit, causes vdev_reopen() to try again. */
219 v->vdev_nowritecache = B_FALSE;
221 /* Physical volume size in bytes */
222 *psize = bdev_capacity(bdev) * block_size;
224 /* Based on the minimum sector size set the block size */
225 *ashift = highbit(MAX(block_size, SPA_MINBLOCKSIZE)) - 1;
227 /* Try to set the io scheduler elevator algorithm */
228 (void) vdev_elevator_switch(v, zfs_vdev_scheduler);
234 vdev_disk_close(vdev_t *v)
236 vdev_disk_t *vd = v->vdev_tsd;
241 if (vd->vd_bdev != NULL)
242 vdev_bdev_close(vd->vd_bdev,
243 vdev_bdev_mode(spa_mode(v->vdev_spa)));
245 kmem_free(vd, sizeof(vdev_disk_t));
249 static dio_request_t *
250 vdev_disk_dio_alloc(int bio_count)
255 dr = kmem_zalloc(sizeof(dio_request_t) +
256 sizeof(struct bio *) * bio_count, KM_SLEEP);
258 init_completion(&dr->dr_comp);
259 atomic_set(&dr->dr_ref, 0);
260 dr->dr_bio_count = bio_count;
263 for (i = 0; i < dr->dr_bio_count; i++)
264 dr->dr_bio[i] = NULL;
271 vdev_disk_dio_free(dio_request_t *dr)
275 for (i = 0; i < dr->dr_bio_count; i++)
277 bio_put(dr->dr_bio[i]);
279 kmem_free(dr, sizeof(dio_request_t) +
280 sizeof(struct bio *) * dr->dr_bio_count);
284 vdev_disk_dio_is_sync(dio_request_t *dr)
286 #ifdef HAVE_BIO_RW_SYNC
287 /* BIO_RW_SYNC preferred interface from 2.6.12-2.6.29 */
288 return (dr->dr_rw & (1 << BIO_RW_SYNC));
290 # ifdef HAVE_BIO_RW_SYNCIO
291 /* BIO_RW_SYNCIO preferred interface from 2.6.30-2.6.35 */
292 return (dr->dr_rw & (1 << BIO_RW_SYNCIO));
294 # ifdef HAVE_REQ_SYNC
295 /* REQ_SYNC preferred interface from 2.6.36-2.6.xx */
296 return (dr->dr_rw & REQ_SYNC);
298 # error "Unable to determine bio sync flag"
299 # endif /* HAVE_REQ_SYNC */
300 # endif /* HAVE_BIO_RW_SYNC */
301 #endif /* HAVE_BIO_RW_SYNCIO */
305 vdev_disk_dio_get(dio_request_t *dr)
307 atomic_inc(&dr->dr_ref);
311 vdev_disk_dio_put(dio_request_t *dr)
313 int rc = atomic_dec_return(&dr->dr_ref);
316 * Free the dio_request when the last reference is dropped and
317 * ensure zio_interpret is called only once with the correct zio
320 zio_t *zio = dr->dr_zio;
321 int error = dr->dr_error;
323 vdev_disk_dio_free(dr);
326 zio->io_delay = jiffies_to_msecs(
327 jiffies_64 - zio->io_delay);
328 zio->io_error = error;
329 ASSERT3S(zio->io_error, >=, 0);
331 vdev_disk_error(zio);
339 BIO_END_IO_PROTO(vdev_disk_physio_completion, bio, size, error)
341 dio_request_t *dr = bio->bi_private;
344 /* Fatal error but print some useful debugging before asserting */
346 PANIC("dr == NULL, bio->bi_private == NULL\n"
347 "bi_next: %p, bi_flags: %lx, bi_rw: %lu, bi_vcnt: %d\n"
348 "bi_idx: %d, bi_size: %d, bi_end_io: %p, bi_cnt: %d\n",
349 bio->bi_next, bio->bi_flags, bio->bi_rw, bio->bi_vcnt,
350 bio->bi_idx, bio->bi_size, bio->bi_end_io,
351 atomic_read(&bio->bi_cnt));
353 #ifndef HAVE_2ARGS_BIO_END_IO_T
356 #endif /* HAVE_2ARGS_BIO_END_IO_T */
358 if (error == 0 && !test_bit(BIO_UPTODATE, &bio->bi_flags))
361 if (dr->dr_error == 0)
362 dr->dr_error = -error;
364 /* Drop reference aquired by __vdev_disk_physio */
365 rc = vdev_disk_dio_put(dr);
367 /* Wake up synchronous waiter this is the last outstanding bio */
368 if ((rc == 1) && vdev_disk_dio_is_sync(dr))
369 complete(&dr->dr_comp);
371 BIO_END_IO_RETURN(0);
374 static inline unsigned long
375 bio_nr_pages(void *bio_ptr, unsigned int bio_size)
377 return ((((unsigned long)bio_ptr + bio_size + PAGE_SIZE - 1) >>
378 PAGE_SHIFT) - ((unsigned long)bio_ptr >> PAGE_SHIFT));
382 bio_map(struct bio *bio, void *bio_ptr, unsigned int bio_size)
384 unsigned int offset, size, i;
387 offset = offset_in_page(bio_ptr);
388 for (i = 0; i < bio->bi_max_vecs; i++) {
389 size = PAGE_SIZE - offset;
397 if (kmem_virt(bio_ptr))
398 page = vmalloc_to_page(bio_ptr);
400 page = virt_to_page(bio_ptr);
402 if (bio_add_page(bio, page, size, offset) != size)
414 __vdev_disk_physio(struct block_device *bdev, zio_t *zio, caddr_t kbuf_ptr,
415 size_t kbuf_size, uint64_t kbuf_offset, int flags)
420 int bio_size, bio_count = 16;
421 int i = 0, error = 0, block_size;
423 ASSERT3U(kbuf_offset + kbuf_size, <=, bdev->bd_inode->i_size);
426 dr = vdev_disk_dio_alloc(bio_count);
430 if (zio && !(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)))
431 bio_set_flags_failfast(bdev, &flags);
435 block_size = vdev_bdev_block_size(bdev);
438 * When the IO size exceeds the maximum bio size for the request
439 * queue we are forced to break the IO in multiple bio's and wait
440 * for them all to complete. Ideally, all pool users will set
441 * their volume block size to match the maximum request size and
442 * the common case will be one bio per vdev IO request.
445 bio_offset = kbuf_offset;
446 bio_size = kbuf_size;
447 for (i = 0; i <= dr->dr_bio_count; i++) {
449 /* Finished constructing bio's for given buffer */
454 * By default only 'bio_count' bio's per dio are allowed.
455 * However, if we find ourselves in a situation where more
456 * are needed we allocate a larger dio and warn the user.
458 if (dr->dr_bio_count == i) {
459 vdev_disk_dio_free(dr);
461 printk("WARNING: Resized bio's/dio to %d\n",bio_count);
465 dr->dr_bio[i] = bio_alloc(GFP_NOIO,
466 bio_nr_pages(bio_ptr, bio_size));
467 if (dr->dr_bio[i] == NULL) {
468 vdev_disk_dio_free(dr);
472 /* Matching put called by vdev_disk_physio_completion */
473 vdev_disk_dio_get(dr);
475 dr->dr_bio[i]->bi_bdev = bdev;
476 dr->dr_bio[i]->bi_sector = bio_offset / block_size;
477 dr->dr_bio[i]->bi_rw = dr->dr_rw;
478 dr->dr_bio[i]->bi_end_io = vdev_disk_physio_completion;
479 dr->dr_bio[i]->bi_private = dr;
481 /* Remaining size is returned to become the new size */
482 bio_size = bio_map(dr->dr_bio[i], bio_ptr, bio_size);
484 /* Advance in buffer and construct another bio if needed */
485 bio_ptr += dr->dr_bio[i]->bi_size;
486 bio_offset += dr->dr_bio[i]->bi_size;
489 /* Extra reference to protect dio_request during submit_bio */
490 vdev_disk_dio_get(dr);
492 zio->io_delay = jiffies_64;
494 /* Submit all bio's associated with this dio */
495 for (i = 0; i < dr->dr_bio_count; i++)
497 submit_bio(dr->dr_rw, dr->dr_bio[i]);
500 * On synchronous blocking requests we wait for all bio the completion
501 * callbacks to run. We will be woken when the last callback runs
502 * for this dio. We are responsible for putting the last dio_request
503 * reference will in turn put back the last bio references. The
504 * only synchronous consumer is vdev_disk_read_rootlabel() all other
505 * IO originating from vdev_disk_io_start() is asynchronous.
507 if (vdev_disk_dio_is_sync(dr)) {
508 wait_for_completion(&dr->dr_comp);
509 error = dr->dr_error;
510 ASSERT3S(atomic_read(&dr->dr_ref), ==, 1);
513 (void)vdev_disk_dio_put(dr);
519 vdev_disk_physio(struct block_device *bdev, caddr_t kbuf,
520 size_t size, uint64_t offset, int flags)
522 bio_set_flags_failfast(bdev, &flags);
523 return __vdev_disk_physio(bdev, NULL, kbuf, size, offset, flags);
526 /* 2.6.24 API change */
527 #ifdef HAVE_BIO_EMPTY_BARRIER
528 BIO_END_IO_PROTO(vdev_disk_io_flush_completion, bio, size, rc)
530 zio_t *zio = bio->bi_private;
532 zio->io_delay = jiffies_to_msecs(jiffies_64 - zio->io_delay);
534 if (rc && (rc == -EOPNOTSUPP))
535 zio->io_vd->vdev_nowritecache = B_TRUE;
538 ASSERT3S(zio->io_error, >=, 0);
540 vdev_disk_error(zio);
543 BIO_END_IO_RETURN(0);
547 vdev_disk_io_flush(struct block_device *bdev, zio_t *zio)
549 struct request_queue *q;
552 q = bdev_get_queue(bdev);
556 bio = bio_alloc(GFP_KERNEL, 0);
560 bio->bi_end_io = vdev_disk_io_flush_completion;
561 bio->bi_private = zio;
563 zio->io_delay = jiffies_64;
564 submit_bio(WRITE_BARRIER, bio);
570 vdev_disk_io_flush(struct block_device *bdev, zio_t *zio)
574 #endif /* HAVE_BIO_EMPTY_BARRIER */
577 vdev_disk_io_start(zio_t *zio)
579 vdev_t *v = zio->io_vd;
580 vdev_disk_t *vd = v->vdev_tsd;
583 switch (zio->io_type) {
586 if (!vdev_readable(v)) {
587 zio->io_error = ENXIO;
588 return ZIO_PIPELINE_CONTINUE;
591 switch (zio->io_cmd) {
592 case DKIOCFLUSHWRITECACHE:
594 if (zfs_nocacheflush)
597 if (v->vdev_nowritecache) {
598 zio->io_error = ENOTSUP;
602 error = vdev_disk_io_flush(vd->vd_bdev, zio);
604 return ZIO_PIPELINE_STOP;
606 zio->io_error = error;
607 if (error == ENOTSUP)
608 v->vdev_nowritecache = B_TRUE;
613 zio->io_error = ENOTSUP;
616 return ZIO_PIPELINE_CONTINUE;
627 zio->io_error = ENOTSUP;
628 return ZIO_PIPELINE_CONTINUE;
631 error = __vdev_disk_physio(vd->vd_bdev, zio, zio->io_data,
632 zio->io_size, zio->io_offset, flags);
634 zio->io_error = error;
635 return ZIO_PIPELINE_CONTINUE;
638 return ZIO_PIPELINE_STOP;
642 vdev_disk_io_done(zio_t *zio)
645 * If the device returned EIO, we revalidate the media. If it is
646 * determined the media has changed this triggers the asynchronous
647 * removal of the device from the configuration.
649 if (zio->io_error == EIO) {
650 vdev_t *v = zio->io_vd;
651 vdev_disk_t *vd = v->vdev_tsd;
653 if (check_disk_change(vd->vd_bdev)) {
654 vdev_bdev_invalidate(vd->vd_bdev);
655 v->vdev_remove_wanted = B_TRUE;
656 spa_async_request(zio->io_spa, SPA_ASYNC_REMOVE);
662 vdev_disk_hold(vdev_t *vd)
664 ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
666 /* We must have a pathname, and it must be absolute. */
667 if (vd->vdev_path == NULL || vd->vdev_path[0] != '/')
671 * Only prefetch path and devid info if the device has
674 if (vd->vdev_tsd != NULL)
677 /* XXX: Implement me as a vnode lookup for the device */
678 vd->vdev_name_vp = NULL;
679 vd->vdev_devid_vp = NULL;
683 vdev_disk_rele(vdev_t *vd)
685 ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
687 /* XXX: Implement me as a vnode rele for the device */
690 vdev_ops_t vdev_disk_ops = {
699 VDEV_TYPE_DISK, /* name of this vdev type */
700 B_TRUE /* leaf vdev */
704 * Given the root disk device devid or pathname, read the label from
705 * the device, and construct a configuration nvlist.
708 vdev_disk_read_rootlabel(char *devpath, char *devid, nvlist_t **config)
710 struct block_device *bdev;
715 bdev = vdev_bdev_open(devpath, vdev_bdev_mode(FREAD), NULL);
717 return -PTR_ERR(bdev);
719 s = bdev_capacity(bdev) * vdev_bdev_block_size(bdev);
721 vdev_bdev_close(bdev, vdev_bdev_mode(FREAD));
725 size = P2ALIGN_TYPED(s, sizeof(vdev_label_t), uint64_t);
726 label = vmem_alloc(sizeof(vdev_label_t), KM_SLEEP);
728 for (i = 0; i < VDEV_LABELS; i++) {
729 uint64_t offset, state, txg = 0;
731 /* read vdev label */
732 offset = vdev_label_offset(size, i, 0);
733 if (vdev_disk_physio(bdev, (caddr_t)label,
734 VDEV_SKIP_SIZE + VDEV_PHYS_SIZE, offset, READ_SYNC) != 0)
737 if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
738 sizeof (label->vl_vdev_phys.vp_nvlist), config, 0) != 0) {
743 if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
744 &state) != 0 || state >= POOL_STATE_DESTROYED) {
745 nvlist_free(*config);
750 if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
751 &txg) != 0 || txg == 0) {
752 nvlist_free(*config);
760 vmem_free(label, sizeof(vdev_label_t));
761 vdev_bdev_close(bdev, vdev_bdev_mode(FREAD));
766 module_param(zfs_vdev_scheduler, charp, 0644);
767 MODULE_PARM_DESC(zfs_vdev_scheduler, "IO Scheduler (noop)");