diff options
author | Mike Snitzer <snitzer@redhat.com> | 2012-09-26 23:45:46 +0100 |
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committer | Alasdair G Kergon <agk@redhat.com> | 2012-09-26 23:45:46 +0100 |
commit | 9bc142dd755d360c08a91ecb107d218787a2e9db (patch) | |
tree | b704174c6d6d3fdf55484fc85bd29ff37808b109 /drivers/md/dm-thin.c | |
parent | 3ae706561637331aa578e52bb89ecbba5edcb7a9 (diff) | |
download | linux-3.10-9bc142dd755d360c08a91ecb107d218787a2e9db.tar.gz linux-3.10-9bc142dd755d360c08a91ecb107d218787a2e9db.tar.bz2 linux-3.10-9bc142dd755d360c08a91ecb107d218787a2e9db.zip |
dm thin: tidy discard support
A little thin discard code refactoring to make the next patch (dm thin:
fix discard support for data devices) more readable.
Pull out a couple of functions (and uses bools instead of unsigned for
features).
No functional changes.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-thin.c')
-rw-r--r-- | drivers/md/dm-thin.c | 64 |
1 files changed, 39 insertions, 25 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index d4209231069..e99f4134dbd 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -509,9 +509,9 @@ enum pool_mode { struct pool_features { enum pool_mode mode; - unsigned zero_new_blocks:1; - unsigned discard_enabled:1; - unsigned discard_passdown:1; + bool zero_new_blocks:1; + bool discard_enabled:1; + bool discard_passdown:1; }; struct thin_c; @@ -1839,6 +1839,32 @@ static void __requeue_bios(struct pool *pool) /*---------------------------------------------------------------- * Binding of control targets to a pool object *--------------------------------------------------------------*/ +static bool data_dev_supports_discard(struct pool_c *pt) +{ + struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); + + return q && blk_queue_discard(q); +} + +/* + * If discard_passdown was enabled verify that the data device + * supports discards. Disable discard_passdown if not; otherwise + * -EOPNOTSUPP will be returned. + */ +static void disable_passdown_if_not_supported(struct pool_c *pt, + struct pool_features *pf) +{ + char buf[BDEVNAME_SIZE]; + + if (!pf->discard_passdown || data_dev_supports_discard(pt)) + return; + + DMWARN("Discard unsupported by data device (%s): Disabling discard passdown.", + bdevname(pt->data_dev->bdev, buf)); + + pf->discard_passdown = false; +} + static int bind_control_target(struct pool *pool, struct dm_target *ti) { struct pool_c *pt = ti->private; @@ -1855,23 +1881,9 @@ static int bind_control_target(struct pool *pool, struct dm_target *ti) pool->ti = ti; pool->low_water_blocks = pt->low_water_blocks; pool->pf = pt->pf; - set_pool_mode(pool, new_mode); - /* - * If discard_passdown was enabled verify that the data device - * supports discards. Disable discard_passdown if not; otherwise - * -EOPNOTSUPP will be returned. - */ - /* FIXME: pull this out into a sep fn. */ - if (pt->pf.discard_passdown) { - struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); - if (!q || !blk_queue_discard(q)) { - char buf[BDEVNAME_SIZE]; - DMWARN("Discard unsupported by data device (%s): Disabling discard passdown.", - bdevname(pt->data_dev->bdev, buf)); - pool->pf.discard_passdown = 0; - } - } + disable_passdown_if_not_supported(pt, &pool->pf); + set_pool_mode(pool, new_mode); return 0; } @@ -1889,9 +1901,9 @@ static void unbind_control_target(struct pool *pool, struct dm_target *ti) static void pool_features_init(struct pool_features *pf) { pf->mode = PM_WRITE; - pf->zero_new_blocks = 1; - pf->discard_enabled = 1; - pf->discard_passdown = 1; + pf->zero_new_blocks = true; + pf->discard_enabled = true; + pf->discard_passdown = true; } static void __pool_destroy(struct pool *pool) @@ -2119,13 +2131,13 @@ static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf, argc--; if (!strcasecmp(arg_name, "skip_block_zeroing")) - pf->zero_new_blocks = 0; + pf->zero_new_blocks = false; else if (!strcasecmp(arg_name, "ignore_discard")) - pf->discard_enabled = 0; + pf->discard_enabled = false; else if (!strcasecmp(arg_name, "no_discard_passdown")) - pf->discard_passdown = 0; + pf->discard_passdown = false; else if (!strcasecmp(arg_name, "read_only")) pf->mode = PM_READ_ONLY; @@ -2261,6 +2273,7 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) pt->low_water_blocks = low_water_blocks; pt->pf = pf; ti->num_flush_requests = 1; + /* * Only need to enable discards if the pool should pass * them down to the data device. The thin device's discard @@ -2268,6 +2281,7 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) */ if (pf.discard_enabled && pf.discard_passdown) { ti->num_discard_requests = 1; + /* * Setting 'discards_supported' circumvents the normal * stacking of discard limits (this keeps the pool and |