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path: root/drivers/md/dm-mpath.c
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Diffstat (limited to 'drivers/md/dm-mpath.c')
-rw-r--r--drivers/md/dm-mpath.c68
1 files changed, 43 insertions, 25 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0c1b8520ef8..785806bdb24 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -63,6 +63,7 @@ struct multipath {
unsigned nr_priority_groups;
struct list_head priority_groups;
unsigned pg_init_required; /* pg_init needs calling? */
+ unsigned pg_init_in_progress; /* Only one pg_init allowed at once */
unsigned nr_valid_paths; /* Total number of usable paths */
struct pgpath *current_pgpath;
@@ -72,7 +73,7 @@ struct multipath {
unsigned queue_io; /* Must we queue all I/O? */
unsigned queue_if_no_path; /* Queue I/O if last path fails? */
- unsigned suspended; /* Has dm core suspended our I/O? */
+ unsigned saved_queue_if_no_path;/* Saved state during suspension */
struct work_struct process_queued_ios;
struct bio_list queued_ios;
@@ -304,11 +305,12 @@ static int map_io(struct multipath *m, struct bio *bio, struct mpath_io *mpio,
m->queue_size--;
if ((pgpath && m->queue_io) ||
- (!pgpath && m->queue_if_no_path && !m->suspended)) {
+ (!pgpath && m->queue_if_no_path)) {
/* Queue for the daemon to resubmit */
bio_list_add(&m->queued_ios, bio);
m->queue_size++;
- if (m->pg_init_required || !m->queue_io)
+ if ((m->pg_init_required && !m->pg_init_in_progress) ||
+ !m->queue_io)
queue_work(kmultipathd, &m->process_queued_ios);
pgpath = NULL;
r = 0;
@@ -333,8 +335,9 @@ static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path)
spin_lock_irqsave(&m->lock, flags);
+ m->saved_queue_if_no_path = m->queue_if_no_path;
m->queue_if_no_path = queue_if_no_path;
- if (!m->queue_if_no_path)
+ if (!m->queue_if_no_path && m->queue_size)
queue_work(kmultipathd, &m->process_queued_ios);
spin_unlock_irqrestore(&m->lock, flags);
@@ -379,25 +382,31 @@ static void process_queued_ios(void *data)
{
struct multipath *m = (struct multipath *) data;
struct hw_handler *hwh = &m->hw_handler;
- struct pgpath *pgpath;
- unsigned init_required, must_queue = 0;
+ struct pgpath *pgpath = NULL;
+ unsigned init_required = 0, must_queue = 1;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
+ if (!m->queue_size)
+ goto out;
+
if (!m->current_pgpath)
__choose_pgpath(m);
pgpath = m->current_pgpath;
- if ((pgpath && m->queue_io) ||
- (!pgpath && m->queue_if_no_path && !m->suspended))
- must_queue = 1;
+ if ((pgpath && !m->queue_io) ||
+ (!pgpath && !m->queue_if_no_path))
+ must_queue = 0;
- init_required = m->pg_init_required;
- if (init_required)
+ if (m->pg_init_required && !m->pg_init_in_progress) {
m->pg_init_required = 0;
+ m->pg_init_in_progress = 1;
+ init_required = 1;
+ }
+out:
spin_unlock_irqrestore(&m->lock, flags);
if (init_required)
@@ -752,6 +761,8 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
static void multipath_dtr(struct dm_target *ti)
{
struct multipath *m = (struct multipath *) ti->private;
+
+ flush_workqueue(kmultipathd);
free_multipath(m);
}
@@ -765,6 +776,9 @@ static int multipath_map(struct dm_target *ti, struct bio *bio,
struct mpath_io *mpio;
struct multipath *m = (struct multipath *) ti->private;
+ if (bio_barrier(bio))
+ return -EOPNOTSUPP;
+
mpio = mempool_alloc(m->mpio_pool, GFP_NOIO);
dm_bio_record(&mpio->details, bio);
@@ -837,7 +851,7 @@ static int reinstate_path(struct pgpath *pgpath)
pgpath->path.is_active = 1;
m->current_pgpath = NULL;
- if (!m->nr_valid_paths++)
+ if (!m->nr_valid_paths++ && m->queue_size)
queue_work(kmultipathd, &m->process_queued_ios);
queue_work(kmultipathd, &m->trigger_event);
@@ -963,12 +977,13 @@ void dm_pg_init_complete(struct path *path, unsigned err_flags)
bypass_pg(m, pg, 1);
spin_lock_irqsave(&m->lock, flags);
- if (!err_flags)
- m->queue_io = 0;
- else {
+ if (err_flags) {
m->current_pgpath = NULL;
m->current_pg = NULL;
- }
+ } else if (!m->pg_init_required)
+ m->queue_io = 0;
+
+ m->pg_init_in_progress = 0;
queue_work(kmultipathd, &m->process_queued_ios);
spin_unlock_irqrestore(&m->lock, flags);
}
@@ -988,9 +1003,12 @@ static int do_end_io(struct multipath *m, struct bio *bio,
if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio))
return error;
+ if (error == -EOPNOTSUPP)
+ return error;
+
spin_lock(&m->lock);
if (!m->nr_valid_paths) {
- if (!m->queue_if_no_path || m->suspended) {
+ if (!m->queue_if_no_path) {
spin_unlock(&m->lock);
return -EIO;
} else {
@@ -1051,27 +1069,27 @@ static int multipath_end_io(struct dm_target *ti, struct bio *bio,
/*
* Suspend can't complete until all the I/O is processed so if
- * the last path failed we will now error any queued I/O.
+ * the last path fails we must error any remaining I/O.
+ * Note that if the freeze_bdev fails while suspending, the
+ * queue_if_no_path state is lost - userspace should reset it.
*/
static void multipath_presuspend(struct dm_target *ti)
{
struct multipath *m = (struct multipath *) ti->private;
- unsigned long flags;
- spin_lock_irqsave(&m->lock, flags);
- m->suspended = 1;
- if (m->queue_if_no_path)
- queue_work(kmultipathd, &m->process_queued_ios);
- spin_unlock_irqrestore(&m->lock, flags);
+ queue_if_no_path(m, 0);
}
+/*
+ * Restore the queue_if_no_path setting.
+ */
static void multipath_resume(struct dm_target *ti)
{
struct multipath *m = (struct multipath *) ti->private;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
- m->suspended = 0;
+ m->queue_if_no_path = m->saved_queue_if_no_path;
spin_unlock_irqrestore(&m->lock, flags);
}