Hi Li,
It seems you sent the same patch again, shoud it be V2 instead?
Thanx
在 11/5/2025 4:46 PM, Li Chen 写道:
From: Li Chen <[email protected]>
Before this change pcache_meta_find_latest() was copying each
slot directly into meta_ret while scanning. If no valid slot
was found and the function returned NULL, meta_ret still held
whatever was last copied (possibly CRC-bad). Later users
(e.g. cache_segs_init) could mistakenly trust that data.
Allocate a temporary buffer instead and only populate meta_ret after a
valid/latest header is found. If no valid header exists we return NULL
without touching meta_ret.
Also add __free(kvfree) so the temporary buffer is always freed, and
include the needed headers.
Signed-off-by: Li Chen <[email protected]>
---
drivers/md/dm-pcache/pcache_internal.h | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/md/dm-pcache/pcache_internal.h
b/drivers/md/dm-pcache/pcache_internal.h
index b7a3319d2bd3e..ac28f9dd2986f 100644
--- a/drivers/md/dm-pcache/pcache_internal.h
+++ b/drivers/md/dm-pcache/pcache_internal.h
@@ -4,6 +4,8 @@
#include <linux/delay.h>
#include <linux/crc32c.h>
+#include <linux/slab.h>
+#include <linux/cleanup.h>
#define pcache_err(fmt, ...) \
pr_err("dm-pcache: %s:%u " fmt, __func__, __LINE__, ##__VA_ARGS__)
@@ -79,14 +81,17 @@ static inline void __must_check
*pcache_meta_find_latest(struct pcache_meta_head
u32 meta_size, u32 meta_max_size,
void *meta_ret)
{
- struct pcache_meta_header *meta, *latest = NULL;
+ struct pcache_meta_header *latest = NULL;
+ struct pcache_meta_header *meta __free(kvfree);
u32 i, seq_latest = 0;
- void *meta_addr;
- meta = meta_ret;
+ meta = kvzalloc(meta_size, GFP_KERNEL);
+ if (!meta)
+ return ERR_PTR(-ENOMEM);
for (i = 0; i < PCACHE_META_INDEX_MAX; i++) {
- meta_addr = (void *)header + (i * meta_max_size);
+ void *meta_addr = (void *)header + (i * meta_max_size);
+
if (copy_mc_to_kernel(meta, meta_addr, meta_size)) {
pcache_err("hardware memory error when copy meta");
return ERR_PTR(-EIO);
