Otherwise IO could be issued to the pool while it is suspended.
Care was taken to properly interlock between the thin and thin-pool
targets when accessing the pool's 'suspended' flag. The thin_ctr will
not add a new thin device to the pool's active_thins list if the pool is
susepended.
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Acked-by: Joe Thornber <ejt@xxxxxxxxxx>
---
drivers/md/dm-thin.c | 55 ++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 45 insertions(+), 10 deletions(-)
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 64fd4de..f1b53e3 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -224,6 +224,7 @@ struct pool {
struct pool_features pf;
bool low_water_triggered:1; /* A dm event has been sent */
+ bool suspended:1;
struct dm_bio_prison *prison;
struct dm_kcopyd_client *copier;
@@ -2575,6 +2576,7 @@ static struct pool *pool_create(struct mapped_device *pool_md,
INIT_LIST_HEAD(&pool->prepared_discards);
INIT_LIST_HEAD(&pool->active_thins);
pool->low_water_triggered = false;
+ pool->suspended = true;
pool->shared_read_ds = dm_deferred_set_create();
if (!pool->shared_read_ds) {
@@ -3119,12 +3121,36 @@ static void pool_resume(struct dm_target *ti)
spin_lock_irqsave(&pool->lock, flags);
pool->low_water_triggered = false;
+ pool->suspended = false;
spin_unlock_irqrestore(&pool->lock, flags);
+
requeue_bios(pool);
do_waker(&pool->waker.work);
}
+static void pool_presuspend(struct dm_target *ti)
+{
+ struct pool_c *pt = ti->private;
+ struct pool *pool = pt->pool;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ pool->suspended = true;
+ spin_unlock_irqrestore(&pool->lock, flags);
+}
+
+static void pool_presuspend_undo(struct dm_target *ti)
+{
+ struct pool_c *pt = ti->private;
+ struct pool *pool = pt->pool;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ pool->suspended = false;
+ spin_unlock_irqrestore(&pool->lock, flags);
+}
+
static void pool_postsuspend(struct dm_target *ti)
{
struct pool_c *pt = ti->private;
@@ -3592,6 +3618,8 @@ static struct target_type pool_target = {
.ctr = pool_ctr,
.dtr = pool_dtr,
.map = pool_map,
+ .presuspend = pool_presuspend,
+ .presuspend_undo = pool_presuspend_undo,
.postsuspend = pool_postsuspend,
.preresume = pool_preresume,
.resume = pool_resume,
@@ -3721,18 +3749,18 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
if (get_pool_mode(tc->pool) == PM_FAIL) {
ti->error = "Couldn't open thin device, Pool is in fail mode";
r = -EINVAL;
- goto bad_thin_open;
+ goto bad_pool;
}
r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
if (r) {
ti->error = "Couldn't open thin internal device";
- goto bad_thin_open;
+ goto bad_pool;
}
r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
if (r)
- goto bad_target_max_io_len;
+ goto bad;
ti->num_flush_bios = 1;
ti->flush_supported = true;
@@ -3747,14 +3775,16 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
ti->split_discard_bios = true;
}
- dm_put(pool_md);
-
mutex_unlock(&dm_thin_pool_table.mutex);
- atomic_set(&tc->refcount, 1);
- init_completion(&tc->can_destroy);
-
spin_lock_irqsave(&tc->pool->lock, flags);
+ if (tc->pool->suspended) {
+ spin_unlock_irqrestore(&tc->pool->lock, flags);
+ mutex_lock(&dm_thin_pool_table.mutex); /* reacquire for __pool_dec */
+ ti->error = "Unable to activate thin device while pool is suspended";
+ r = -EINVAL;
+ goto bad;
+ }
list_add_tail_rcu(&tc->list, &tc->pool->active_thins);
spin_unlock_irqrestore(&tc->pool->lock, flags);
/*
@@ -3765,11 +3795,16 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
*/
synchronize_rcu();
+ dm_put(pool_md);
+
+ atomic_set(&tc->refcount, 1);
+ init_completion(&tc->can_destroy);
+
return 0;
-bad_target_max_io_len:
+bad:
dm_pool_close_thin_device(tc->td);
-bad_thin_open:
+bad_pool:
__pool_dec(tc->pool);
bad_pool_lookup:
dm_put(pool_md);
--
1.9.3
--
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