Re: [PATCH v2] ext4: fix the time handling macros when ext4 is using small inodes

Theodore Ts'o
2023-07-20T14:48:33Z

On Wed, Jul 19, 2023 at 06:32:19AM -0400, Jeff Layton wrote:
> If ext4 is using small on-disk inodes, then it may not be able to store
> fine grained timestamps. It also can't store the i_crtime at all in that
> case since that fully lives in the extended part of the inode.
>
> 979492850abd got the EXT4_EINODE_{GET,SET}_XTIME macros wrong, and would
> still store the tv_sec field of the i_crtime into the raw_inode, even
> when they were small, corrupting adjacent memory.
>
> This fixes those macros to skip setting anything in the raw_inode if the
> tv_sec field doesn't fit, and to properly return a {0,0} timestamp when
> the raw_inode doesn't support it.
>
> Also, fix a bug in ctime handling during rename. It was updating the
> renamed inode's ctime twice rather than the old directory.
>
> Cc: Jan Kara <jack@suse.cz>
> Fixes: 979492850abd ("ext4: convert to ctime accessor functions")
> Reported-by: Hugh Dickins <hughd@google.com>
> Tested-by: Hugh Dickins <hughd@google.com>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

Acked-by: Theodore Ts'o <tytso@mit.edu>

I assume this is will be applied to the vfs.ctime branch, yes?

- Ted