在 12/2/2025 8:11 PM, Li Chen 写道:
From: Li Chen <[email protected]>
The on-media cache_info index used sizeof(struct) instead of the
4K metadata stride, so gc_percent updates from dmsetup message
were written between slots and lost after reboot. Use
PCACHE_CACHE_INFO_SIZE in get_cache_info_addr() and align
info_index with the slot returned by pcache_meta_find_latest().
Signed-off-by: Li Chen <[email protected]>
---
drivers/md/dm-pcache/cache.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/md/dm-pcache/cache.c b/drivers/md/dm-pcache/cache.c
index 698697a7a73c..6d5001548628 100644
--- a/drivers/md/dm-pcache/cache.c
+++ b/drivers/md/dm-pcache/cache.c
@@ -8,9 +8,11 @@
struct kmem_cache *key_cache;
-static inline struct pcache_cache_info *get_cache_info_addr(struct pcache_cache *cache)
+static inline struct pcache_cache_info *
+get_cache_info_addr(struct pcache_cache *cache)
{
- return cache->cache_info_addr + cache->info_index;
+ return (struct pcache_cache_info *)((char *)cache->cache_info_addr +
+ (size_t)cache->info_index *
PCACHE_CACHE_INFO_SIZE);
}
static void cache_info_write(struct pcache_cache *cache)
@@ -40,7 +42,12 @@ static int cache_info_init(struct pcache_cache *cache,
struct pcache_cache_optio
if (IS_ERR(cache_info_addr))
return PTR_ERR(cache_info_addr);
- if (cache_info_addr) {
+ if (cache_info_addr) {
this is unrelated change, and it introduce error in checkpatch.pl
# ./scripts/checkpatch.pl drivers/md/dm-pcache/cache.c
WARNING: please, no spaces at the start of a line
#45: FILE: drivers/md/dm-pcache/cache.c:45:
+ if (cache_info_addr) {$
WARNING: suspect code indent for conditional statements (4, 16)
#45: FILE: drivers/md/dm-pcache/cache.c:45:
+ if (cache_info_addr) {
+ int index = ((char *)cache_info_addr - (char
*)cache->cache_info_addr) /
total: 0 errors, 2 warnings, 452 lines checked
+ int index = ((char *)cache_info_addr - (char
*)cache->cache_info_addr) /
+ PCACHE_CACHE_INFO_SIZE;
+
+ cache->info_index = (index + 1) % PCACHE_META_INDEX_MAX;
Don't advance info_index at init stage, cache->info_index means the
current index, not the next index.
It will be advanced in cache_info_write() after write cache_info into
next slot.
In addition, cache->info_index initialization should be after the
data_crc checking.
Thanx
+
if (opts->data_crc !=
(cache->cache_info.flags &
PCACHE_CACHE_FLAGS_DATA_CRC)) {
pcache_dev_err(pcache, "invalid option for data_crc: %s,
expected: %s",
