• Mingming Cao's avatar
    "ext4_ext_put_in_cache" uses __u32 to receive physical block number · dd54567a
    Mingming Cao authored
    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: default avatarMingming Cao <cmm@us.ibm.com>
    Cc: Yan Zheng <yanzheng@21cn.com>
    Cc: <stable@kernel.org>
    Cc: <linux-ext4@vger.kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    dd54567a
extents.c 67 KB