diff options
author | Mike Snitzer <snitzer@redhat.com> | 2013-09-20 02:49:11 +0400 |
---|---|---|
committer | Mike Snitzer <snitzer@redhat.com> | 2013-09-23 18:42:06 +0400 |
commit | b60ab990ccdf34b0159bf5ff52f4acee7c940d78 (patch) | |
tree | 9a05149474e38190b0ed676ec98853ce5099da44 /drivers | |
parent | f84cb8a46a771f36a04a02c61ea635c968ed5f6a (diff) | |
download | linux-b60ab990ccdf34b0159bf5ff52f4acee7c940d78.tar.xz |
dm thin: do not expose non-zero discard limits if discards disabled
Fix issue where the block layer would stack the discard limits of the
pool's data device even if the "ignore_discard" pool feature was
specified.
The pool and thin device(s) still had discards disabled because the
QUEUE_FLAG_DISCARD request_queue flag wasn't set. But to avoid user
confusion when "ignore_discard" is used: both the pool device and the
thin device(s) have zeroes for all discard limits.
Also, always set discard_zeroes_data_unsupported in targets because they
should never advertise the 'discard_zeroes_data' capability (even if the
pool's data device supports it).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/md/dm-thin.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index ed063427d676..2c0cf511ec23 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -2095,6 +2095,7 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) * them down to the data device. The thin device's discard * processing will cause mappings to be removed from the btree. */ + ti->discard_zeroes_data_unsupported = true; if (pf.discard_enabled && pf.discard_passdown) { ti->num_discard_bios = 1; @@ -2104,7 +2105,6 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) * thin devices' discard limits consistent). */ ti->discards_supported = true; - ti->discard_zeroes_data_unsupported = true; } ti->private = pt; @@ -2689,8 +2689,16 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) * They get transferred to the live pool in bind_control_target() * called from pool_preresume(). */ - if (!pt->adjusted_pf.discard_enabled) + if (!pt->adjusted_pf.discard_enabled) { + /* + * Must explicitly disallow stacking discard limits otherwise the + * block layer will stack them if pool's data device has support. + * QUEUE_FLAG_DISCARD wouldn't be set but there is no way for the + * user to see that, so make sure to set all discard limits to 0. + */ + limits->discard_granularity = 0; return; + } disable_passdown_if_not_supported(pt); @@ -2826,10 +2834,10 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv) ti->per_bio_data_size = sizeof(struct dm_thin_endio_hook); /* In case the pool supports discards, pass them on. */ + ti->discard_zeroes_data_unsupported = true; if (tc->pool->pf.discard_enabled) { ti->discards_supported = true; ti->num_discard_bios = 1; - ti->discard_zeroes_data_unsupported = true; /* Discard bios must be split on a block boundary */ ti->split_discard_bios = true; } |