"ext4_ext_put_in_cache" uses __u32 to receive physical block number
Yan Zheng wrote:
> I think I found a bug in ext4/extents.c, "ext4_ext_put_in_cache" uses
> "__u32" to receive physical block number. "ext4_ext_put_in_cache" is
> used in "ext4_ext_get_blocks", it sets ext4 inode's extent cache
> according most recently tree lookup (higher 16 bits of saved physical
> block number are always zero). when serving a mapping request,
> "ext4_ext_get_blocks" first check whether the logical block is in
> inode's extent cache. if the logical block is in the cache and the
> cached region isn't a gap, "ext4_ext_get_blocks" gets physical block
> number by using cached region's physical block number and offset in
> the cached region. as described above, "ext4_ext_get_blocks" may
> return wrong result when there are physical block numbers bigger than
> 0xffffffff.
>
You are right. Thanks for reporting this!
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Cc: Yan Zheng <yanzheng@21cn.com>
Cc: <stable@kernel.org>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 750c46f..78beb09 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1544,7 +1544,7 @@
static void
ext4_ext_put_in_cache(struct inode *inode, __u32 block,
- __u32 len, __u32 start, int type)
+ __u32 len, ext4_fsblk_t start, int type)
{
struct ext4_ext_cache *cex;
BUG_ON(len == 0);