Commit 44d814ce authored Mar 06, 2008 by David Chinner Committed by Lachlan McIlroy Apr 18, 2008

[XFS] Update c/mtime correctly on truncates



XFS changes the c/mtime of an inode when truncating it to the same size.
The c/mtime is only supposed to change if the size is changed. Not to be
confused with ftruncate, where the c/mtime is supposed to be changed even
if the size is not changed.

The Linux VFS encodes this semantic difference in the flags it sends down
to ->setattr, which XFS currently ignores. We need to make XFS pay
attention to the VFS flags and hence Do The Right Thing.

SGI-PV: 977547
SGI-Modid: xfs-linux-melb:xfs-kern:30536a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

parent 24bd861d

fs/xfs/xfs_vnodeops.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -633,6 +633,15 @@ xfs_setattr(
		* Truncate file. Must have write permission and not be a directory.
		*/
		if (mask & XFS_AT_SIZE) {
		/*
		* Only change the c/mtime if we are changing the size
		* or we are explicitly asked to change it. This handles
		* the semantic difference between truncate() and ftruncate()
		* as implemented in the VFS.
		*/
		if (vap->va_size != ip->i_size \|\| (mask & XFS_AT_CTIME))
		timeflags \|= XFS_ICHGTIME_MOD \| XFS_ICHGTIME_CHG;

		if (vap->va_size > ip->i_size) {
		xfs_igrow_finish(tp, ip, vap->va_size,
		!(flags & ATTR_DMI));
		@@ -661,10 +670,6 @@ xfs_setattr(
		*/
		xfs_iflags_set(ip, XFS_ITRUNCATED);
		}
		/*
		* Have to do this even if the file's size doesn't change.
		*/
		timeflags \|= XFS_ICHGTIME_MOD \| XFS_ICHGTIME_CHG;
		}

		/*