Commit 80c57893 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm thin: add 'no_space_timeout' dm-thin-pool module param

Commit 85ad643b

 ("dm thin: add timeout to stop out-of-data-space mode
holding IO forever") introduced a fixed 60 second timeout.  Users may
want to either disable or modify this timeout.

Allow the out-of-data-space timeout to be configured using the
'no_space_timeout' dm-thin-pool module param.  Setting it to 0 will
disable the timeout, resulting in IO being queued until more data space
is added to the thin-pool.
Signed-off-by: default avatarMike Snitzer <>
Cc: # 3.14+
parent 4cdd2ad7
......@@ -309,7 +309,10 @@ ii) Status
If the pool runs out of data or metadata space, the pool will
either queue or error the IO destined to the data device. The
default is to queue the IO until more space is added.
default is to queue the IO until more space is added or the
'no_space_timeout' expires. The 'no_space_timeout' dm-thin-pool
module parameter can be used to change this timeout -- it
defaults to 60 seconds but may be disabled using a value of 0.
iii) Messages
......@@ -27,7 +27,9 @@
#define MAPPING_POOL_SIZE 1024
#define PRISON_CELLS 1024
#define NO_SPACE_TIMEOUT (HZ * 60)
static unsigned no_space_timeout_secs = NO_SPACE_TIMEOUT_SECS;
"A percentage of time allocated for copy on write");
......@@ -1670,6 +1672,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
struct pool_c *pt = pool->ti->private;
bool needs_check = dm_pool_metadata_needs_check(pool->pmd);
enum pool_mode old_mode = get_pool_mode(pool);
unsigned long no_space_timeout = ACCESS_ONCE(no_space_timeout_secs) * HZ;
* Never allow the pool to transition to PM_WRITE mode if user
......@@ -1732,8 +1735,8 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
pool->process_prepared_mapping = process_prepared_mapping;
pool->process_prepared_discard = process_prepared_discard_passdown;
if (!pool->pf.error_if_no_space)
queue_delayed_work(pool->wq, &pool->no_space_timeout, NO_SPACE_TIMEOUT);
if (!pool->pf.error_if_no_space && no_space_timeout)
queue_delayed_work(pool->wq, &pool->no_space_timeout, no_space_timeout);
case PM_WRITE:
......@@ -3508,6 +3511,9 @@ static void dm_thin_exit(void)
module_param_named(no_space_timeout, no_space_timeout_secs, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(no_space_timeout, "Out of data space queue IO timeout in seconds");
MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
MODULE_AUTHOR("Joe Thornber <>");
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment