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lvm2/bug-1172566_cachevol-use-cachepool-code-for-metadata-size.patch
Gang He b956656551 Accepting request 814709 from home:hmzhao:branches:openSUSE:Factory
- problem with LVM cache (data loss) (bsc#1172566)
  + bug-1172566_cachevol-use-cachepool-code-for-metadata-size.patch

OBS-URL: https://build.opensuse.org/request/show/814709
OBS-URL: https://build.opensuse.org/package/show/Base:System/lvm2?expand=0&rev=275
2020-06-15 13:05:31 +00:00

57 lines
2.1 KiB
Diff

By heming.zhao@suse.com
this patch is based on upstream commit
```
commit c08704cee7e34a96fdaa453faf900683283e8691
Author: David Teigland <teigland@redhat.com>
Date: Mon Oct 21 12:13:33 2019 -0500
cachevol: use cachepool code for metadata size
Based on a more detailed calculation, but because of
extent size rounding, the final result is about the
same.
```
diff -Nupr a/lib/metadata/cache_manip.c b/lib/metadata/cache_manip.c
--- a/lib/metadata/cache_manip.c 2020-06-12 09:04:17.474637002 +0800
+++ b/lib/metadata/cache_manip.c 2020-06-12 09:04:28.914578582 +0800
@@ -184,12 +184,16 @@ void cache_check_for_warns(const struct
*/
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);
+ /* Used space for mapping and hints for each cached chunk in bytes
+ * (matching thin-tools cache_metadata_size.cc) */
+ const uint64_t chunk_overhead = (DM_BYTES_PER_BLOCK + DM_MAX_HINT_WIDTH + DM_HINT_OVERHEAD_PER_BLOCK);
+ const uint64_t transaction_overhead = DM_TRANSACTION_OVERHEAD * 1024; /* 4MiB */
+
+ /* Number of cache chunks we have in caching volume */
+ uint64_t nr_chunks = data_size / chunk_size;
+ /* Minimal size of metadata volume converted back to sectors */
+ uint64_t min_meta_size = (transaction_overhead + nr_chunks * chunk_overhead +
+ (SECTOR_SIZE - 1)) >> SECTOR_SHIFT;
return min_meta_size;
}
@@ -1242,14 +1246,7 @@ int cache_vol_set_params(struct cmd_cont
}
if (!meta_size) {
- if (pool_lv->size < (128 * ONE_MB_S))
- meta_size = 16 * ONE_MB_S;
-
- else if (pool_lv->size < ONE_GB_S)
- meta_size = 32 * ONE_MB_S;
-
- else if (pool_lv->size < (128 * ONE_GB_S))
- meta_size = 64 * ONE_MB_S;
+ meta_size = _cache_min_metadata_size(pool_lv->size, chunk_size);
if (meta_size > (pool_lv->size / 2))
meta_size = pool_lv->size / 2;