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authorMike Snitzer <snitzer@redhat.com>2017-10-10 23:02:41 +0200
committerShaohua Li <shli@fb.com>2017-10-17 04:06:36 +0200
commit935fe0983e09f4f7331ebf5ea4ae2124f6e9f9e8 (patch)
treea3debe3ff3a5c4462b416f8992577d30c06a8a8a /drivers/md/multipath.c
parentmd: raid10: remove VLAIS (diff)
downloadlinux-935fe0983e09f4f7331ebf5ea4ae2124f6e9f9e8.tar.xz
linux-935fe0983e09f4f7331ebf5ea4ae2124f6e9f9e8.zip
md: rename some drivers/md/ files to have an "md-" prefix
Motivated by the desire to illiminate the imprecise nature of DM-specific patches being unnecessarily sent to both the MD maintainer and mailing-list. Which is born out of the fact that DM files also reside in drivers/md/ Now all MD-specific files in drivers/md/ start with either "raid" or "md-" and the MAINTAINERS file has been updated accordingly. Shaohua: don't change module name Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/multipath.c')
-rw-r--r--drivers/md/multipath.c509
1 files changed, 0 insertions, 509 deletions
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
deleted file mode 100644
index b68e0666b9b0..000000000000
--- a/drivers/md/multipath.c
+++ /dev/null
@@ -1,509 +0,0 @@
-/*
- * multipath.c : Multiple Devices driver for Linux
- *
- * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
- *
- * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
- *
- * MULTIPATH management functions.
- *
- * derived from raid1.c.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * You should have received a copy of the GNU General Public License
- * (for example /usr/src/linux/COPYING); if not, write to the Free
- * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#include <linux/blkdev.h>
-#include <linux/module.h>
-#include <linux/raid/md_u.h>
-#include <linux/seq_file.h>
-#include <linux/slab.h>
-#include "md.h"
-#include "multipath.h"
-
-#define MAX_WORK_PER_DISK 128
-
-#define NR_RESERVED_BUFS 32
-
-static int multipath_map (struct mpconf *conf)
-{
- int i, disks = conf->raid_disks;
-
- /*
- * Later we do read balancing on the read side
- * now we use the first available disk.
- */
-
- rcu_read_lock();
- for (i = 0; i < disks; i++) {
- struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
- if (rdev && test_bit(In_sync, &rdev->flags) &&
- !test_bit(Faulty, &rdev->flags)) {
- atomic_inc(&rdev->nr_pending);
- rcu_read_unlock();
- return i;
- }
- }
- rcu_read_unlock();
-
- pr_crit_ratelimited("multipath_map(): no more operational IO paths?\n");
- return (-1);
-}
-
-static void multipath_reschedule_retry (struct multipath_bh *mp_bh)
-{
- unsigned long flags;
- struct mddev *mddev = mp_bh->mddev;
- struct mpconf *conf = mddev->private;
-
- spin_lock_irqsave(&conf->device_lock, flags);
- list_add(&mp_bh->retry_list, &conf->retry_list);
- spin_unlock_irqrestore(&conf->device_lock, flags);
- md_wakeup_thread(mddev->thread);
-}
-
-/*
- * multipath_end_bh_io() is called when we have finished servicing a multipathed
- * operation and are ready to return a success/failure code to the buffer
- * cache layer.
- */
-static void multipath_end_bh_io(struct multipath_bh *mp_bh, blk_status_t status)
-{
- struct bio *bio = mp_bh->master_bio;
- struct mpconf *conf = mp_bh->mddev->private;
-
- bio->bi_status = status;
- bio_endio(bio);
- mempool_free(mp_bh, conf->pool);
-}
-
-static void multipath_end_request(struct bio *bio)
-{
- struct multipath_bh *mp_bh = bio->bi_private;
- struct mpconf *conf = mp_bh->mddev->private;
- struct md_rdev *rdev = conf->multipaths[mp_bh->path].rdev;
-
- if (!bio->bi_status)
- multipath_end_bh_io(mp_bh, 0);
- else if (!(bio->bi_opf & REQ_RAHEAD)) {
- /*
- * oops, IO error:
- */
- char b[BDEVNAME_SIZE];
- md_error (mp_bh->mddev, rdev);
- pr_info("multipath: %s: rescheduling sector %llu\n",
- bdevname(rdev->bdev,b),
- (unsigned long long)bio->bi_iter.bi_sector);
- multipath_reschedule_retry(mp_bh);
- } else
- multipath_end_bh_io(mp_bh, bio->bi_status);
- rdev_dec_pending(rdev, conf->mddev);
-}
-
-static bool multipath_make_request(struct mddev *mddev, struct bio * bio)
-{
- struct mpconf *conf = mddev->private;
- struct multipath_bh * mp_bh;
- struct multipath_info *multipath;
-
- if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
- md_flush_request(mddev, bio);
- return true;
- }
-
- mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
-
- mp_bh->master_bio = bio;
- mp_bh->mddev = mddev;
-
- mp_bh->path = multipath_map(conf);
- if (mp_bh->path < 0) {
- bio_io_error(bio);
- mempool_free(mp_bh, conf->pool);
- return true;
- }
- multipath = conf->multipaths + mp_bh->path;
-
- bio_init(&mp_bh->bio, NULL, 0);
- __bio_clone_fast(&mp_bh->bio, bio);
-
- mp_bh->bio.bi_iter.bi_sector += multipath->rdev->data_offset;
- bio_set_dev(&mp_bh->bio, multipath->rdev->bdev);
- mp_bh->bio.bi_opf |= REQ_FAILFAST_TRANSPORT;
- mp_bh->bio.bi_end_io = multipath_end_request;
- mp_bh->bio.bi_private = mp_bh;
- mddev_check_writesame(mddev, &mp_bh->bio);
- mddev_check_write_zeroes(mddev, &mp_bh->bio);
- generic_make_request(&mp_bh->bio);
- return true;
-}
-
-static void multipath_status(struct seq_file *seq, struct mddev *mddev)
-{
- struct mpconf *conf = mddev->private;
- int i;
-
- seq_printf (seq, " [%d/%d] [", conf->raid_disks,
- conf->raid_disks - mddev->degraded);
- rcu_read_lock();
- for (i = 0; i < conf->raid_disks; i++) {
- struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
- seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
- }
- rcu_read_unlock();
- seq_printf (seq, "]");
-}
-
-static int multipath_congested(struct mddev *mddev, int bits)
-{
- struct mpconf *conf = mddev->private;
- int i, ret = 0;
-
- rcu_read_lock();
- for (i = 0; i < mddev->raid_disks ; i++) {
- struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
- if (rdev && !test_bit(Faulty, &rdev->flags)) {
- struct request_queue *q = bdev_get_queue(rdev->bdev);
-
- ret |= bdi_congested(q->backing_dev_info, bits);
- /* Just like multipath_map, we just check the
- * first available device
- */
- break;
- }
- }
- rcu_read_unlock();
- return ret;
-}
-
-/*
- * Careful, this can execute in IRQ contexts as well!
- */
-static void multipath_error (struct mddev *mddev, struct md_rdev *rdev)
-{
- struct mpconf *conf = mddev->private;
- char b[BDEVNAME_SIZE];
-
- if (conf->raid_disks - mddev->degraded <= 1) {
- /*
- * Uh oh, we can do nothing if this is our last path, but
- * first check if this is a queued request for a device
- * which has just failed.
- */
- pr_warn("multipath: only one IO path left and IO error.\n");
- /* leave it active... it's all we have */
- return;
- }
- /*
- * Mark disk as unusable
- */
- if (test_and_clear_bit(In_sync, &rdev->flags)) {
- unsigned long flags;
- spin_lock_irqsave(&conf->device_lock, flags);
- mddev->degraded++;
- spin_unlock_irqrestore(&conf->device_lock, flags);
- }
- set_bit(Faulty, &rdev->flags);
- set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
- pr_err("multipath: IO failure on %s, disabling IO path.\n"
- "multipath: Operation continuing on %d IO paths.\n",
- bdevname(rdev->bdev, b),
- conf->raid_disks - mddev->degraded);
-}
-
-static void print_multipath_conf (struct mpconf *conf)
-{
- int i;
- struct multipath_info *tmp;
-
- pr_debug("MULTIPATH conf printout:\n");
- if (!conf) {
- pr_debug("(conf==NULL)\n");
- return;
- }
- pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
- conf->raid_disks);
-
- for (i = 0; i < conf->raid_disks; i++) {
- char b[BDEVNAME_SIZE];
- tmp = conf->multipaths + i;
- if (tmp->rdev)
- pr_debug(" disk%d, o:%d, dev:%s\n",
- i,!test_bit(Faulty, &tmp->rdev->flags),
- bdevname(tmp->rdev->bdev,b));
- }
-}
-
-static int multipath_add_disk(struct mddev *mddev, struct md_rdev *rdev)
-{
- struct mpconf *conf = mddev->private;
- struct request_queue *q;
- int err = -EEXIST;
- int path;
- struct multipath_info *p;
- int first = 0;
- int last = mddev->raid_disks - 1;
-
- if (rdev->raid_disk >= 0)
- first = last = rdev->raid_disk;
-
- print_multipath_conf(conf);
-
- for (path = first; path <= last; path++)
- if ((p=conf->multipaths+path)->rdev == NULL) {
- q = rdev->bdev->bd_disk->queue;
- disk_stack_limits(mddev->gendisk, rdev->bdev,
- rdev->data_offset << 9);
-
- err = md_integrity_add_rdev(rdev, mddev);
- if (err)
- break;
- spin_lock_irq(&conf->device_lock);
- mddev->degraded--;
- rdev->raid_disk = path;
- set_bit(In_sync, &rdev->flags);
- spin_unlock_irq(&conf->device_lock);
- rcu_assign_pointer(p->rdev, rdev);
- err = 0;
- break;
- }
-
- print_multipath_conf(conf);
-
- return err;
-}
-
-static int multipath_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
-{
- struct mpconf *conf = mddev->private;
- int err = 0;
- int number = rdev->raid_disk;
- struct multipath_info *p = conf->multipaths + number;
-
- print_multipath_conf(conf);
-
- if (rdev == p->rdev) {
- if (test_bit(In_sync, &rdev->flags) ||
- atomic_read(&rdev->nr_pending)) {
- pr_warn("hot-remove-disk, slot %d is identified but is still operational!\n", number);
- err = -EBUSY;
- goto abort;
- }
- p->rdev = NULL;
- if (!test_bit(RemoveSynchronized, &rdev->flags)) {
- synchronize_rcu();
- if (atomic_read(&rdev->nr_pending)) {
- /* lost the race, try later */
- err = -EBUSY;
- p->rdev = rdev;
- goto abort;
- }
- }
- err = md_integrity_register(mddev);
- }
-abort:
-
- print_multipath_conf(conf);
- return err;
-}
-
-/*
- * This is a kernel thread which:
- *
- * 1. Retries failed read operations on working multipaths.
- * 2. Updates the raid superblock when problems encounter.
- * 3. Performs writes following reads for array syncronising.
- */
-
-static void multipathd(struct md_thread *thread)
-{
- struct mddev *mddev = thread->mddev;
- struct multipath_bh *mp_bh;
- struct bio *bio;
- unsigned long flags;
- struct mpconf *conf = mddev->private;
- struct list_head *head = &conf->retry_list;
-
- md_check_recovery(mddev);
- for (;;) {
- char b[BDEVNAME_SIZE];
- spin_lock_irqsave(&conf->device_lock, flags);
- if (list_empty(head))
- break;
- mp_bh = list_entry(head->prev, struct multipath_bh, retry_list);
- list_del(head->prev);
- spin_unlock_irqrestore(&conf->device_lock, flags);
-
- bio = &mp_bh->bio;
- bio->bi_iter.bi_sector = mp_bh->master_bio->bi_iter.bi_sector;
-
- if ((mp_bh->path = multipath_map (conf))<0) {
- pr_err("multipath: %s: unrecoverable IO read error for block %llu\n",
- bio_devname(bio, b),
- (unsigned long long)bio->bi_iter.bi_sector);
- multipath_end_bh_io(mp_bh, BLK_STS_IOERR);
- } else {
- pr_err("multipath: %s: redirecting sector %llu to another IO path\n",
- bio_devname(bio, b),
- (unsigned long long)bio->bi_iter.bi_sector);
- *bio = *(mp_bh->master_bio);
- bio->bi_iter.bi_sector +=
- conf->multipaths[mp_bh->path].rdev->data_offset;
- bio_set_dev(bio, conf->multipaths[mp_bh->path].rdev->bdev);
- bio->bi_opf |= REQ_FAILFAST_TRANSPORT;
- bio->bi_end_io = multipath_end_request;
- bio->bi_private = mp_bh;
- generic_make_request(bio);
- }
- }
- spin_unlock_irqrestore(&conf->device_lock, flags);
-}
-
-static sector_t multipath_size(struct mddev *mddev, sector_t sectors, int raid_disks)
-{
- WARN_ONCE(sectors || raid_disks,
- "%s does not support generic reshape\n", __func__);
-
- return mddev->dev_sectors;
-}
-
-static int multipath_run (struct mddev *mddev)
-{
- struct mpconf *conf;
- int disk_idx;
- struct multipath_info *disk;
- struct md_rdev *rdev;
- int working_disks;
-
- if (md_check_no_bitmap(mddev))
- return -EINVAL;
-
- if (mddev->level != LEVEL_MULTIPATH) {
- pr_warn("multipath: %s: raid level not set to multipath IO (%d)\n",
- mdname(mddev), mddev->level);
- goto out;
- }
- /*
- * copy the already verified devices into our private MULTIPATH
- * bookkeeping area. [whatever we allocate in multipath_run(),
- * should be freed in multipath_free()]
- */
-
- conf = kzalloc(sizeof(struct mpconf), GFP_KERNEL);
- mddev->private = conf;
- if (!conf)
- goto out;
-
- conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks,
- GFP_KERNEL);
- if (!conf->multipaths)
- goto out_free_conf;
-
- working_disks = 0;
- rdev_for_each(rdev, mddev) {
- disk_idx = rdev->raid_disk;
- if (disk_idx < 0 ||
- disk_idx >= mddev->raid_disks)
- continue;
-
- disk = conf->multipaths + disk_idx;
- disk->rdev = rdev;
- disk_stack_limits(mddev->gendisk, rdev->bdev,
- rdev->data_offset << 9);
-
- if (!test_bit(Faulty, &rdev->flags))
- working_disks++;
- }
-
- conf->raid_disks = mddev->raid_disks;
- conf->mddev = mddev;
- spin_lock_init(&conf->device_lock);
- INIT_LIST_HEAD(&conf->retry_list);
-
- if (!working_disks) {
- pr_warn("multipath: no operational IO paths for %s\n",
- mdname(mddev));
- goto out_free_conf;
- }
- mddev->degraded = conf->raid_disks - working_disks;
-
- conf->pool = mempool_create_kmalloc_pool(NR_RESERVED_BUFS,
- sizeof(struct multipath_bh));
- if (conf->pool == NULL)
- goto out_free_conf;
-
- mddev->thread = md_register_thread(multipathd, mddev,
- "multipath");
- if (!mddev->thread)
- goto out_free_conf;
-
- pr_info("multipath: array %s active with %d out of %d IO paths\n",
- mdname(mddev), conf->raid_disks - mddev->degraded,
- mddev->raid_disks);
- /*
- * Ok, everything is just fine now
- */
- md_set_array_sectors(mddev, multipath_size(mddev, 0, 0));
-
- if (md_integrity_register(mddev))
- goto out_free_conf;
-
- return 0;
-
-out_free_conf:
- mempool_destroy(conf->pool);
- kfree(conf->multipaths);
- kfree(conf);
- mddev->private = NULL;
-out:
- return -EIO;
-}
-
-static void multipath_free(struct mddev *mddev, void *priv)
-{
- struct mpconf *conf = priv;
-
- mempool_destroy(conf->pool);
- kfree(conf->multipaths);
- kfree(conf);
-}
-
-static struct md_personality multipath_personality =
-{
- .name = "multipath",
- .level = LEVEL_MULTIPATH,
- .owner = THIS_MODULE,
- .make_request = multipath_make_request,
- .run = multipath_run,
- .free = multipath_free,
- .status = multipath_status,
- .error_handler = multipath_error,
- .hot_add_disk = multipath_add_disk,
- .hot_remove_disk= multipath_remove_disk,
- .size = multipath_size,
- .congested = multipath_congested,
-};
-
-static int __init multipath_init (void)
-{
- return register_md_personality (&multipath_personality);
-}
-
-static void __exit multipath_exit (void)
-{
- unregister_md_personality (&multipath_personality);
-}
-
-module_init(multipath_init);
-module_exit(multipath_exit);
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("simple multi-path personality for MD");
-MODULE_ALIAS("md-personality-7"); /* MULTIPATH */
-MODULE_ALIAS("md-multipath");
-MODULE_ALIAS("md-level--4");