dm pcache: fix segment info indexing
Segment info indexing also used sizeof(struct) instead of the
4K metadata stride, so info_index could point between slots and
subsequent writes would advance incorrectly. Derive info_index
from the pointer returned by the segment meta search using
PCACHE_SEG_INFO_SIZE and advance to the next slot for future
updates.
Signed-off-by: Li Chen <chenl311@chinatelecom.cn>
Signed-off-by: Dongsheng Yang <dongsheng.yang@linux.dev>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Zheng Gu <cengku@gmail.com>
Cc: stable@vger.kernel.org # 6.18
diff --git a/drivers/md/dm-pcache/cache_segment.c b/drivers/md/dm-pcache/cache_segment.c
index ae57cc2..9d92e2b 100644
--- a/drivers/md/dm-pcache/cache_segment.c
+++ b/drivers/md/dm-pcache/cache_segment.c
@@ -56,7 +56,10 @@ static int cache_seg_info_load(struct pcache_cache_segment *cache_seg)
ret = -EIO;
goto out;
}
- cache_seg->info_index = cache_seg_info_addr - cache_seg_info_addr_base;
+
+ cache_seg->info_index =
+ ((char *)cache_seg_info_addr - (char *)cache_seg_info_addr_base) /
+ PCACHE_SEG_INFO_SIZE;
out:
mutex_unlock(&cache_seg->info_lock);
