From: Hannes Reinecke <hare@suse.de>
Date: Thu, 19 Nov 2009 13:54:56 +0100
Subject: Accept failed paths for multipath maps
References: bnc#458037,bnc#458393
Patch-Mainline: submitted to dm-devel 12/18/2013
The multipath kernel module is rejecting any map with an invalid
device. However, as the multipathd is processing the events serially
it will try to push a map with invalid devices if more than one
device failed at the same time.
So we can as well accept those maps and make sure to mark the
paths as down.
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/md/dm-mpath.c | 112 +++++++++++++++++++++++++++++++++++++-------------
drivers/md/dm-mpath.h | 1 +
drivers/md/dm-table.c | 3 ++
3 files changed, 88 insertions(+), 28 deletions(-)
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0e8ab5b..0d277f9 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -166,7 +166,8 @@ static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
list_for_each_entry_safe(pgpath, tmp, pgpaths, list) {
list_del(&pgpath->list);
- dm_put_device(ti, pgpath->path.dev);
+ if (pgpath->path.dev)
+ dm_put_device(ti, pgpath->path.dev);
free_pgpath(pgpath);
}
}
@@ -366,6 +367,9 @@ static struct pgpath *choose_path_in_pg(struct multipath *m,
pgpath = path_to_pgpath(path);
+ if (!pgpath->path.dev)
+ return ERR_PTR(-ENODEV);
+
if (unlikely(lockless_dereference(m->current_pg) != pg)) {
/* Only update current_pgpath if pg changed */
spin_lock_irqsave(&m->lock, flags);
@@ -469,7 +473,7 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
struct pgpath *pgpath;
struct block_device *bdev;
struct dm_mpath_io *mpio = get_mpio(map_context);
- struct request_queue *q;
+ struct request_queue *q = NULL;
struct request *clone;
/* Do we need to select a new pgpath? */
@@ -493,12 +497,16 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
mpio->pgpath = pgpath;
mpio->nr_bytes = nr_bytes;
- bdev = pgpath->path.dev->bdev;
- q = bdev_get_queue(bdev);
- clone = blk_get_request(q, rq->cmd_flags | REQ_NOMERGE, GFP_ATOMIC);
+ if (pgpath->path.dev) {
+ bdev = pgpath->path.dev->bdev;
+ q = bdev_get_queue(bdev);
+ clone = blk_get_request(q, rq->cmd_flags | REQ_NOMERGE,
+ GFP_ATOMIC);
+ } else
+ clone = ERR_PTR(-ENODEV);
if (IS_ERR(clone)) {
/* EBUSY, ENODEV or EWOULDBLOCK: requeue */
- bool queue_dying = blk_queue_dying(q);
+ bool queue_dying = q ? blk_queue_dying(q) : false;
DMERR_LIMIT("blk_get_request() returned %ld%s - requeuing",
PTR_ERR(clone), queue_dying ? " (path offline)" : "");
if (queue_dying) {
@@ -555,7 +563,7 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
return DM_MAPIO_SUBMITTED;
}
- if (!pgpath) {
+ if (!pgpath || !pgpath->path.dev) {
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
return DM_MAPIO_REQUEUE;
dm_report_EIO(m);
@@ -733,6 +741,7 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
{
int r;
struct pgpath *p;
+ const char *path;
struct multipath *m = ti->private;
struct request_queue *q = NULL;
const char *attached_handler_name;
@@ -747,17 +756,40 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
if (!p)
return ERR_PTR(-ENOMEM);
- r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table),
+ path = dm_shift_arg(as);
+ r = dm_get_device(ti, path, dm_table_get_mode(ti->table),
&p->path.dev);
if (r) {
- ti->error = "error getting device";
- goto bad;
+ unsigned major, minor;
+
+ /* Try to add a failed device */
+ if (r == -ENXIO && sscanf(path, "%u:%u", &major, &minor) == 2) {
+ dev_t dev;
+
+ /* Extract the major/minor numbers */
+ dev = MKDEV(major, minor);
+ if (MAJOR(dev) != major || MINOR(dev) != minor) {
+ /* Nice try, didn't work */
+ DMWARN("Invalid device path %s", path);
+ ti->error = "error converting devnum";
+ goto bad;
+ }
+ DMWARN("adding disabled device %d:%d", major, minor);
+ p->path.dev = NULL;
+ format_dev_t(p->path.pdev, dev);
+ p->is_active = 0;
+ } else {
+ ti->error = "error getting device";
+ goto bad;
+ }
+ } else {
+ memcpy(p->path.pdev, p->path.dev->name, 16);
}
- if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) || m->hw_handler_name)
+ if (p->path.dev)
q = bdev_get_queue(p->path.dev->bdev);
- if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) {
+ if (q && test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) {
retain:
attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
if (attached_handler_name) {
@@ -781,7 +813,7 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
}
}
- if (m->hw_handler_name) {
+ if (q && m->hw_handler_name) {
r = scsi_dh_attach(q, m->hw_handler_name);
if (r == -EBUSY) {
char b[BDEVNAME_SIZE];
@@ -809,10 +841,16 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error);
if (r) {
- dm_put_device(ti, p->path.dev);
+ if (p->path.dev)
+ dm_put_device(ti, p->path.dev);
goto bad;
}
+ if (!p->is_active) {
+ ps->type->fail_path(ps, &p->path);
+ p->fail_count++;
+ atomic_dec(&m->nr_valid_paths);
+ }
return p;
bad:
@@ -1157,10 +1195,10 @@ static int fail_path(struct pgpath *pgpath)
spin_lock_irqsave(&m->lock, flags);
- if (!pgpath->is_active)
+ if (!pgpath->path.dev || !pgpath->is_active)
goto out;
- DMWARN("Failing path %s.", pgpath->path.dev->name);
+ DMWARN("Failing path %s.", pgpath->path.pdev);
pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
pgpath->is_active = false;
@@ -1172,7 +1210,7 @@ static int fail_path(struct pgpath *pgpath)
m->current_pgpath = NULL;
dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
- pgpath->path.dev->name, atomic_read(&m->nr_valid_paths));
+ pgpath->path.pdev, atomic_read(&m->nr_valid_paths));
schedule_work(&m->trigger_event);
@@ -1197,7 +1235,13 @@ static int reinstate_path(struct pgpath *pgpath)
if (pgpath->is_active)
goto out;
- DMWARN("Reinstating path %s.", pgpath->path.dev->name);
+ if (!pgpath->path.dev) {
+ DMWARN("Cannot reinstate disabled path %s", pgpath->path.pdev);
+ r = -ENODEV;
+ goto out;
+ }
+
+ DMWARN("Reinstating path %s.", pgpath->path.pdev);
r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path);
if (r)
@@ -1215,7 +1259,7 @@ static int reinstate_path(struct pgpath *pgpath)
}
dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
- pgpath->path.dev->name, nr_valid_paths);
+ pgpath->path.pdev, nr_valid_paths);
schedule_work(&m->trigger_event);
@@ -1239,6 +1283,9 @@ static int action_dev(struct multipath *m, struct dm_dev *dev,
struct pgpath *pgpath;
struct priority_group *pg;
+ if (!dev)
+ return 0;
+
list_for_each_entry(pg, &m->priority_groups, list) {
list_for_each_entry(pgpath, &pg->pgpaths, list) {
if (pgpath->path.dev == dev)
@@ -1434,12 +1481,15 @@ static void pg_init_done(void *data, int errors)
static void activate_or_offline_path(struct pgpath *pgpath)
{
- struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
- if (pgpath->is_active && !blk_queue_dying(q))
- scsi_dh_activate(q, pg_init_done, pgpath);
- else
- pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED);
+ if (pgpath->path.dev) {
+ struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
+ if (pgpath->is_active && !blk_queue_dying(q)) {
+ scsi_dh_activate(q, pg_init_done, pgpath);
+ return;
+ }
+ }
+ pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED);
}
static void activate_path_work(struct work_struct *work)
@@ -1692,7 +1742,7 @@ static void multipath_status(struct dm_target *ti, status_type_t type,
pg->ps.type->info_args);
list_for_each_entry(p, &pg->pgpaths, list) {
- DMEMIT("%s %s %u ", p->path.dev->name,
+ DMEMIT("%s %s %u ", p->path.pdev,
p->is_active ? "A" : "F",
p->fail_count);
if (pg->ps.type->status)
@@ -1718,7 +1768,7 @@ static void multipath_status(struct dm_target *ti, status_type_t type,
pg->ps.type->table_args);
list_for_each_entry(p, &pg->pgpaths, list) {
- DMEMIT("%s ", p->path.dev->name);
+ DMEMIT("%s ", p->path.pdev);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps,
&p->path, type, result + sz,
@@ -1805,7 +1855,7 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
if (!current_pgpath)
current_pgpath = choose_pgpath(m, 0);
- if (current_pgpath) {
+ if (current_pgpath && current_pgpath->path.dev) {
if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) {
*bdev = current_pgpath->path.dev->bdev;
*mode = current_pgpath->path.dev->mode;
@@ -1851,6 +1901,8 @@ static int multipath_iterate_devices(struct dm_target *ti,
list_for_each_entry(pg, &m->priority_groups, list) {
list_for_each_entry(p, &pg->pgpaths, list) {
+ if (!p->path.dev)
+ continue;
ret = fn(ti, p->path.dev, ti->begin, ti->len, data);
if (ret)
goto out;
@@ -1863,8 +1915,12 @@ static int multipath_iterate_devices(struct dm_target *ti,
static int pgpath_busy(struct pgpath *pgpath)
{
- struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
+ struct request_queue *q;
+
+ if (!pgpath->path.dev)
+ return 0;
+ q = bdev_get_queue(pgpath->path.dev->bdev);
return blk_lld_busy(q);
}
diff --git a/drivers/md/dm-mpath.h b/drivers/md/dm-mpath.h
index e230f71..f97388d 100644
--- a/drivers/md/dm-mpath.h
+++ b/drivers/md/dm-mpath.h
@@ -12,6 +12,7 @@
struct dm_dev;
struct dm_path {
+ char pdev[16]; /* Requested physical device */
struct dm_dev *dev; /* Read-only */
void *pscontext; /* For path-selector use */
};
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 28a4071..a6190fb 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -504,6 +504,9 @@ void dm_put_device(struct dm_target *ti, struct dm_dev *d)
struct list_head *devices = &ti->table->devices;
struct dm_dev_internal *dd;
+ if (!d)
+ return;
+
list_for_each_entry(dd, devices, list) {
if (dd->dm_dev == d) {
found = 1;
--
1.8.5.6