From 80c578930ce77ba8bcfb226a184b482020bdda7b Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 20 May 2014 13:38:33 -0400 Subject: [PATCH] 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: Mike Snitzer Cc: stable@vger.kernel.org # 3.14+ --- Documentation/device-mapper/thin-provisioning.txt | 5 ++++- drivers/md/dm-thin.c | 12 +++++++++--- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/Documentation/device-mapper/thin-provisioning.txt b/Documentation/device-mapper/thin-provisioning.txt index 05a27e9..2f51735 100644 --- a/Documentation/device-mapper/thin-provisioning.txt +++ b/Documentation/device-mapper/thin-provisioning.txt @@ -309,7 +309,10 @@ ii) Status error_if_no_space|queue_if_no_space 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 diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 2e71de8..242ac2e 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -27,7 +27,9 @@ #define MAPPING_POOL_SIZE 1024 #define PRISON_CELLS 1024 #define COMMIT_PERIOD HZ -#define NO_SPACE_TIMEOUT (HZ * 60) +#define NO_SPACE_TIMEOUT_SECS 60 + +static unsigned no_space_timeout_secs = NO_SPACE_TIMEOUT_SECS; DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle, "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); break; case PM_WRITE: @@ -3508,6 +3511,9 @@ static void dm_thin_exit(void) module_init(dm_thin_init); module_exit(dm_thin_exit); +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 "); MODULE_LICENSE("GPL"); -- 2.7.4