diff options
author | Joe Thornber <ejt@redhat.com> | 2016-09-15 09:23:46 -0400 |
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committer | Mike Snitzer <snitzer@redhat.com> | 2016-09-22 11:15:02 -0400 |
commit | 4e781b498ee5008ede91362d91404a362e7a46b3 (patch) | |
tree | 039f3914f839b455759253fb0395a639a1912dae /drivers/md/dm-cache-metadata.c | |
parent | dd6a77d99859ab963503e67372ed278fe8ceab26 (diff) | |
download | linux-4e781b498ee5008ede91362d91404a362e7a46b3.tar.bz2 |
dm cache: speed up writing of the hint array
It's far quicker to always delete the hint array and recreate with
dm_array_new() because we avoid the copying caused by mutation.
Also simplifies the policy interface, replacing the walk_hints() with
the simpler get_hint().
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-cache-metadata.c')
-rw-r--r-- | drivers/md/dm-cache-metadata.c | 80 |
1 files changed, 27 insertions, 53 deletions
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index 3970cda10080..a60f10a0ee0a 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -1368,10 +1368,24 @@ int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, /*----------------------------------------------------------------*/ -static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) +static int get_hint(uint32_t index, void *value_le, void *context) +{ + uint32_t value; + struct dm_cache_policy *policy = context; + + value = policy_get_hint(policy, to_cblock(index)); + *((__le32 *) value_le) = cpu_to_le32(value); + + return 0; +} + +/* + * It's quicker to always delete the hint array, and recreate with + * dm_array_new(). + */ +static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) { int r; - __le32 value; size_t hint_size; const char *policy_name = dm_cache_policy_get_name(policy); const unsigned *policy_version = dm_cache_policy_get_version(policy); @@ -1380,63 +1394,23 @@ static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *po (strlen(policy_name) > sizeof(cmd->policy_name) - 1)) return -EINVAL; - if (!policy_unchanged(cmd, policy)) { - strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); - memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version)); + strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); + memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version)); - hint_size = dm_cache_policy_get_hint_size(policy); - if (!hint_size) - return 0; /* short-circuit hints initialization */ - cmd->policy_hint_size = hint_size; + hint_size = dm_cache_policy_get_hint_size(policy); + if (!hint_size) + return 0; /* short-circuit hints initialization */ + cmd->policy_hint_size = hint_size; - if (cmd->hint_root) { - r = dm_array_del(&cmd->hint_info, cmd->hint_root); - if (r) - return r; - } - - r = dm_array_empty(&cmd->hint_info, &cmd->hint_root); + if (cmd->hint_root) { + r = dm_array_del(&cmd->hint_info, cmd->hint_root); if (r) return r; - - value = cpu_to_le32(0); - __dm_bless_for_disk(&value); - r = dm_array_resize(&cmd->hint_info, cmd->hint_root, 0, - from_cblock(cmd->cache_blocks), - &value, &cmd->hint_root); - if (r) - return r; - } - - return 0; -} - -static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock, uint32_t hint) -{ - struct dm_cache_metadata *cmd = context; - __le32 value = cpu_to_le32(hint); - int r; - - __dm_bless_for_disk(&value); - - r = dm_array_set_value(&cmd->hint_info, cmd->hint_root, - from_cblock(cblock), &value, &cmd->hint_root); - cmd->changed = true; - - return r; -} - -static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) -{ - int r; - - r = begin_hints(cmd, policy); - if (r) { - DMERR("begin_hints failed"); - return r; } - return policy_walk_mappings(policy, save_hint, cmd); + return dm_array_new(&cmd->hint_info, &cmd->hint_root, + from_cblock(cmd->cache_blocks), + get_hint, policy); } int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) |