Hi Jonathan, ---- On Mon, 03 Nov 2025 19:38:03 +0800 Jonathan Cameron <[email protected]> wrote --- > On Thu, 30 Oct 2025 20:33:21 +0800 > Li Chen <[email protected]> wrote: > > > 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); > See the guidance notes in cleanup.h THis hsould be > > struct pcache_meta_header *meta __free(kvfree) = > kvzalloc(meta_size, GFP_KERNEL); > > That is the constructor and destructor must be together. Inline variable > declarations are fine for this one type of use.
I appreciate your suggestion very much. Regards, Li
