On Fri, May 15, 2009 at 10:25:08AM +0530, Aneesh Kumar K.V wrote: > So the fix is correct, but we need to update the commit message. Here's the updated commit message. - Ted ext4: Fix race in ext4_inode_info.i_cached_extent If two CPU's simultaneously call ext4_ext_get_blocks() at the same time, there is nothing protecting the i_cached_extent structure from being used and updated at the same time. This could potentially cause the wrong location on disk to be read or written to, including potentially causing the corruption of the block group descriptors and/or inode table. This bug has been in the ext4 code since almost the very beginning of ext4's development. Fortunately once the data is stored in the page cache cache, ext4_get_blocks() doesn't need to be called, so trying to replicate this problem to the point where we could identify its root cause was *extremely* difficult. Many thanks to Kevin Shanahan for working over several months to be able to reproduce this easily so we could finally nail down the cause of the corruption. Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
