Re: [PATCH v2 04/12] fat: only specify I_DIRTY_TIME when needed in fat_update_time()

On Mon, Jan 11, 2021 at 11:50:27AM -0800, Eric Biggers wrote:

On Mon, Jan 11, 2021 at 11:52:01AM +0100, Christoph Hellwig wrote:

quoted

On Fri, Jan 08, 2021 at 11:58:55PM -0800, Eric Biggers wrote:

quoted

+	if ((flags & S_VERSION) && inode_maybe_inc_iversion(inode, false))
+		dirty_flags |= I_DIRTY_SYNC;

fat does not support i_version updates, so this bit can be skipped.

Is that really the case?  Any filesystem (including fat) can be mounted with
"iversion", which causes SB_I_VERSION to be set.

A lot of filesystems (including fat) don't store i_version to disk, but it looks
like it will still get updated in-memory.  Could anything be relying on that?

As Dave pointed out i_version can't really work for fat.  But I guess
that is indeed out of scope for this series, so let's go ahead with this
version for now:

Reviewed-by: Christoph Hellwig <hch@lst.de>