On Wed 24-08-22 18:03:48, Lukas Czerner wrote:
> Currently the I_DIRTY_TIME will never get set if the inode already has
> I_DIRTY_INODE with assumption that it supersedes I_DIRTY_TIME. That's
> true, however ext4 will only update the on-disk inode in
> ->dirty_inode(), not on actual writeback. As a result if the inode
> already has I_DIRTY_INODE state by the time we get to
> __mark_inode_dirty() only with I_DIRTY_TIME, the time was already filled
> into on-disk inode and will not get updated until the next I_DIRTY_INODE
> update, which might never come if we crash or get a power failure.
>
> The problem can be reproduced on ext4 by running xfstest generic/622
> with -o iversion mount option.
>
> Fix it by allowing I_DIRTY_TIME to be set even if the inode already has
> I_DIRTY_INODE. Also make sure that the case is properly handled in
> writeback_single_inode() as well. Additionally changes in
> xfs_fs_dirty_inode() was made to accommodate for I_DIRTY_TIME in flag.
>
> Thanks Jan Kara for suggestions on how to make this work properly.
>
> Cc: Dave Chinner <david@xxxxxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
> Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx>
> Suggested-by: Jan Kara <jack@xxxxxxx>
Looks good to me. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Just two nits below:
> @@ -2369,6 +2374,17 @@ void __mark_inode_dirty(struct inode *inode, int flags)
> trace_writeback_mark_inode_dirty(inode, flags);
>
> if (flags & I_DIRTY_INODE) {
> +
Pointless empty line here.
> + /* Inode timestamp update will piggback on this dirtying */
Maybe expand this comment to:
/*
* Inode timestamp update will piggback on this dirtying.
* We tell ->dirty_inode callback that timestamps need to
* be updated by setting I_DIRTY_TIME in flags.
*/
> + if (inode->i_state & I_DIRTY_TIME) {
> + spin_lock(&inode->i_lock);
> + if (inode->i_state & I_DIRTY_TIME) {
> + inode->i_state &= ~I_DIRTY_TIME;
> + flags |= I_DIRTY_TIME;
> + }
> + spin_unlock(&inode->i_lock);
> + }
> +
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
