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mirror of git://sourceware.org/git/lvm2.git synced 2024-10-27 18:55:19 +03:00

cache: function for min metadata size estimation

Move min code into reusable function.
This commit is contained in:
Zdenek Kabelac 2016-04-28 18:08:36 +02:00
parent 7c1e601164
commit 00dfca034c

View File

@ -120,6 +120,23 @@ void cache_check_for_warns(const struct lv_segment *seg)
"resized and require manual uncache before resize!");
}
/*
* Returns minimum size of cache metadata volume for give data and chunk size
* (all values in sector)
* Default meta size is: (Overhead + mapping size + hint size)
*/
static uint64_t _cache_min_metadata_size(uint64_t data_size, uint32_t chunk_size)
{
uint64_t min_meta_size;
min_meta_size = data_size / chunk_size; /* nr_chunks */
min_meta_size *= (DM_BYTES_PER_BLOCK + DM_MAX_HINT_WIDTH + DM_HINT_OVERHEAD_PER_BLOCK);
min_meta_size = (min_meta_size + (SECTOR_SIZE - 1)) >> SECTOR_SHIFT; /* in sectors */
min_meta_size += DM_TRANSACTION_OVERHEAD * (1024 >> SECTOR_SHIFT);
return min_meta_size;
}
int update_cache_pool_params(const struct segment_type *segtype,
struct volume_group *vg, unsigned attr,
int passed_args, uint32_t pool_data_extents,
@ -128,7 +145,7 @@ int update_cache_pool_params(const struct segment_type *segtype,
{
uint64_t min_meta_size;
uint32_t extent_size = vg->extent_size;
uint64_t pool_metadata_size = (uint64_t) *pool_metadata_extents * vg->extent_size;
uint64_t pool_metadata_size = (uint64_t) *pool_metadata_extents * extent_size;
if (!(passed_args & PASS_ARG_CHUNK_SIZE))
*chunk_size = DEFAULT_CACHE_POOL_CHUNK_SIZE * 2;
@ -136,14 +153,7 @@ int update_cache_pool_params(const struct segment_type *segtype,
if (!validate_pool_chunk_size(vg->cmd, segtype, *chunk_size))
return_0;
/*
* Default meta size is:
* (Overhead + mapping size + hint size)
*/
min_meta_size = (uint64_t) pool_data_extents * extent_size / *chunk_size; /* nr_chunks */
min_meta_size *= (DM_BYTES_PER_BLOCK + DM_MAX_HINT_WIDTH + DM_HINT_OVERHEAD_PER_BLOCK);
min_meta_size = (min_meta_size + (SECTOR_SIZE - 1)) >> SECTOR_SHIFT; /* in sectors */
min_meta_size += DM_TRANSACTION_OVERHEAD * (1024 >> SECTOR_SHIFT);
min_meta_size = _cache_min_metadata_size((uint64_t) pool_data_extents * extent_size, *chunk_size);
/* Round up to extent size */
if (min_meta_size % extent_size)