Commit 9b7aaa64 authored by Joe Thornber's avatar Joe Thornber Committed by Mike Snitzer

dm thin: allow pool in read-only mode to transition to read-write mode

A thin-pool may be in read-only mode because the pool's data or metadata
space was exhausted.  To allow for recovery, by adding more space to the
pool, we must allow a pool to transition from PM_READ_ONLY to PM_WRITE
mode.  Otherwise, running out of space will render the pool permanently
read-only.
Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
parent 5383ef3a
......@@ -1697,6 +1697,14 @@ void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
up_write(&pmd->root_lock);
}
void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
{
down_write(&pmd->root_lock);
pmd->read_only = false;
dm_bm_set_read_write(pmd->bm);
up_write(&pmd->root_lock);
}
int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
dm_block_t threshold,
dm_sm_threshold_fn fn,
......
......@@ -193,6 +193,7 @@ int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_siz
* that nothing is changing.
*/
void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd);
void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd);
int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
dm_block_t threshold,
......
......@@ -1425,6 +1425,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode mode)
break;
case PM_WRITE:
dm_pool_metadata_read_write(pool->pmd);
pool->process_bio = process_bio;
pool->process_discard = process_discard;
pool->process_prepared_mapping = process_prepared_mapping;
......@@ -1641,12 +1642,19 @@ static int bind_control_target(struct pool *pool, struct dm_target *ti)
struct pool_c *pt = ti->private;
/*
* We want to make sure that degraded pools are never upgraded.
* We want to make sure that a pool in PM_FAIL mode is never upgraded.
*/
enum pool_mode old_mode = pool->pf.mode;
enum pool_mode new_mode = pt->adjusted_pf.mode;
if (old_mode > new_mode)
/*
* If we were in PM_FAIL mode, rollback of metadata failed. We're
* not going to recover without a thin_repair. So we never let the
* pool move out of the old mode. On the other hand a PM_READ_ONLY
* may have been due to a lack of metadata or data space, and may
* now work (ie. if the underlying devices have been resized).
*/
if (old_mode == PM_FAIL)
new_mode = old_mode;
pool->ti = ti;
......
......@@ -626,6 +626,12 @@ void dm_bm_set_read_only(struct dm_block_manager *bm)
}
EXPORT_SYMBOL_GPL(dm_bm_set_read_only);
void dm_bm_set_read_write(struct dm_block_manager *bm)
{
bm->read_only = false;
}
EXPORT_SYMBOL_GPL(dm_bm_set_read_write);
u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor)
{
return crc32c(~(u32) 0, data, len) ^ init_xor;
......
......@@ -108,8 +108,8 @@ int dm_bm_unlock(struct dm_block *b);
int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
struct dm_block *superblock);
/*
* Request data be prefetched into the cache.
/*
* Request data is prefetched into the cache.
*/
void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b);
......@@ -125,6 +125,7 @@ void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b);
* be returned if you do.
*/
void dm_bm_set_read_only(struct dm_block_manager *bm);
void dm_bm_set_read_write(struct dm_block_manager *bm);
u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor);
......
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