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Commit d14fcf3d authored by Joe Thornber's avatar Joe Thornber Committed by Mike Snitzer
Browse files

dm cache: make sure every metadata function checks fail_io 



Otherwise operations may be attempted that will only ever go on to crash
(since the metadata device is either missing or unreliable if 'fail_io'
is set).

Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
parent 3f068040

drivers/md/dm-cache-metadata.c

+59 −39
Original line number Diff line number Diff line
@@ -868,18 +868,39 @@ static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd, 
}



#define WRITE_LOCK(cmd)	\

	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \

	down_write(&cmd->root_lock); \

	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \

		up_write(&cmd->root_lock); \

		return -EINVAL; \

	down_write(&cmd->root_lock)

	}



#define WRITE_LOCK_VOID(cmd) \

	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \

	down_write(&cmd->root_lock); \

	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \

		up_write(&cmd->root_lock); \

		return; \

	down_write(&cmd->root_lock)

	}



#define WRITE_UNLOCK(cmd) \

	up_write(&cmd->root_lock)



#define READ_LOCK(cmd) \

	down_read(&cmd->root_lock); \

	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \

		up_read(&cmd->root_lock); \

		return -EINVAL; \

	}



#define READ_LOCK_VOID(cmd)	\

	down_read(&cmd->root_lock); \

	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \

		up_read(&cmd->root_lock); \

		return; \

	}



#define READ_UNLOCK(cmd) \

	up_read(&cmd->root_lock)



int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)

{

	int r;
@@ -1015,22 +1036,20 @@ int dm_cache_load_discards(struct dm_cache_metadata *cmd, 
{

	int r;



	down_read(&cmd->root_lock);

	READ_LOCK(cmd);

	r = __load_discards(cmd, fn, context);

	up_read(&cmd->root_lock);

	READ_UNLOCK(cmd);



	return r;

}



dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd)

int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result)

{

	dm_cblock_t r;

	READ_LOCK(cmd);

	*result = cmd->cache_blocks;

	READ_UNLOCK(cmd);



	down_read(&cmd->root_lock);

	r = cmd->cache_blocks;

	up_read(&cmd->root_lock);



	return r;

	return 0;

}



static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
@@ -1188,9 +1207,9 @@ int dm_cache_load_mappings(struct dm_cache_metadata *cmd, 
{

	int r;



	down_read(&cmd->root_lock);

	READ_LOCK(cmd);

	r = __load_mappings(cmd, policy, fn, context);

	up_read(&cmd->root_lock);

	READ_UNLOCK(cmd);



	return r;

}
@@ -1215,18 +1234,18 @@ static int __dump_mappings(struct dm_cache_metadata *cmd) 


void dm_cache_dump(struct dm_cache_metadata *cmd)

{

	down_read(&cmd->root_lock);

	READ_LOCK_VOID(cmd);

	__dump_mappings(cmd);

	up_read(&cmd->root_lock);

	READ_UNLOCK(cmd);

}



int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)

{

	int r;



	down_read(&cmd->root_lock);

	READ_LOCK(cmd);

	r = cmd->changed;

	up_read(&cmd->root_lock);

	READ_UNLOCK(cmd);



	return r;

}
@@ -1276,9 +1295,9 @@ int dm_cache_set_dirty(struct dm_cache_metadata *cmd, 
void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,

				 struct dm_cache_statistics *stats)

{

	down_read(&cmd->root_lock);

	READ_LOCK_VOID(cmd);

	*stats = cmd->stats;

	up_read(&cmd->root_lock);

	READ_UNLOCK(cmd);

}



void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
@@ -1312,9 +1331,9 @@ int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, 
{

	int r = -EINVAL;



	down_read(&cmd->root_lock);

	READ_LOCK(cmd);

	r = dm_sm_get_nr_free(cmd->metadata_sm, result);

	up_read(&cmd->root_lock);

	READ_UNLOCK(cmd);



	return r;

}
@@ -1324,9 +1343,9 @@ int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, 
{

	int r = -EINVAL;



	down_read(&cmd->root_lock);

	READ_LOCK(cmd);

	r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);

	up_read(&cmd->root_lock);

	READ_UNLOCK(cmd);



	return r;

}
@@ -1417,7 +1436,13 @@ int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy * 


int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)

{

	return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);

	int r;



	READ_LOCK(cmd);

	r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);

	READ_UNLOCK(cmd);



	return r;

}



void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
@@ -1440,10 +1465,7 @@ int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd) 
	struct dm_block *sblock;

	struct cache_disk_superblock *disk_super;



	/*

	 * We ignore fail_io for this function.

	 */

	down_write(&cmd->root_lock);

	WRITE_LOCK(cmd);

	set_bit(NEEDS_CHECK, &cmd->flags);



	r = superblock_lock(cmd, &sblock);
@@ -1458,19 +1480,17 @@ int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd) 
	dm_bm_unlock(sblock);



out:

	up_write(&cmd->root_lock);

	WRITE_UNLOCK(cmd);

	return r;

}



bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd)

int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result)

{

	bool needs_check;

	READ_LOCK(cmd);

	*result = !!test_bit(NEEDS_CHECK, &cmd->flags);

	READ_UNLOCK(cmd);



	down_read(&cmd->root_lock);

	needs_check = !!test_bit(NEEDS_CHECK, &cmd->flags);

	up_read(&cmd->root_lock);



	return needs_check;

	return 0;

}



int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)

drivers/md/dm-cache-metadata.h

+2 −2
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ void dm_cache_metadata_close(struct dm_cache_metadata *cmd); 
 * origin blocks to map to.

 */

int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size);

dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd);

int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result);



int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,

				   sector_t discard_block_size,
@@ -137,7 +137,7 @@ int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy * 
 */

int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result);



bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd);

int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result);

int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd);

void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd);

void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd);

drivers/md/dm-cache-target.c

+10 −2
Original line number Diff line number Diff line
@@ -984,9 +984,14 @@ static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mod 


static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode)

{

	bool needs_check = dm_cache_metadata_needs_check(cache->cmd);

	bool needs_check;

	enum cache_metadata_mode old_mode = get_cache_mode(cache);



	if (dm_cache_metadata_needs_check(cache->cmd, &needs_check)) {

		DMERR("unable to read needs_check flag, setting failure mode");

		new_mode = CM_FAIL;

	}



	if (new_mode == CM_WRITE && needs_check) {

		DMERR("%s: unable to switch cache to write mode until repaired.",

		      cache_device_name(cache));
@@ -3510,6 +3515,7 @@ static void cache_status(struct dm_target *ti, status_type_t type, 
	char buf[BDEVNAME_SIZE];

	struct cache *cache = ti->private;

	dm_cblock_t residency;

	bool needs_check;



	switch (type) {

	case STATUSTYPE_INFO:
@@ -3583,7 +3589,9 @@ static void cache_status(struct dm_target *ti, status_type_t type, 
		else

			DMEMIT("rw ");



		if (dm_cache_metadata_needs_check(cache->cmd))

		r = dm_cache_metadata_needs_check(cache->cmd, &needs_check);



		if (r || needs_check)

			DMEMIT("needs_check ");

		else

			DMEMIT("- ");