Patch "xfs: don't change inode mode if ACL update fails" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    xfs: don't change inode mode if ACL update fails

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xfs-don-t-change-inode-mode-if-acl-update-fails.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 67f2ffe31d1a683170c2ba0ecc643e42a5fdd397 Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner@redhat.com>
Date: Mon, 9 Oct 2017 11:37:23 -0700
Subject: xfs: don't change inode mode if ACL update fails

From: Dave Chinner <dchinner@redhat.com>

commit 67f2ffe31d1a683170c2ba0ecc643e42a5fdd397 upstream.

If we get ENOSPC half way through setting the ACL, the inode mode
can still be changed even though the ACL does not exist. Reorder the
operation to only change the mode of the inode if the ACL is set
correctly.

Whilst this does not fix the problem with crash consistency (that requires
attribute addition to be a deferred op) it does prevent ENOSPC and other
non-fatal errors setting an xattr to be handled sanely.

This fixes xfstests generic/449.

Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/xfs/xfs_acl.c |   22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -247,6 +247,8 @@ xfs_set_mode(struct inode *inode, umode_
 int
 xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
+	umode_t mode;
+	bool set_mode = false;
 	int error = 0;
 
 	if (!acl)
@@ -257,16 +259,24 @@ xfs_set_acl(struct inode *inode, struct
 		return error;
 
 	if (type == ACL_TYPE_ACCESS) {
-		umode_t mode;
-
 		error = posix_acl_update_mode(inode, &mode, &acl);
 		if (error)
 			return error;
-		error = xfs_set_mode(inode, mode);
-		if (error)
-			return error;
+		set_mode = true;
 	}
 
  set_acl:
-	return __xfs_set_acl(inode, acl, type);
+	error =  __xfs_set_acl(inode, acl, type);
+	if (error)
+		return error;
+
+	/*
+	 * We set the mode after successfully updating the ACL xattr because the
+	 * xattr update can fail at ENOSPC and we don't want to change the mode
+	 * if the ACL update hasn't been applied.
+	 */
+	if (set_mode)
+		error = xfs_set_mode(inode, mode);
+
+	return error;
 }


Patches currently in stable-queue which might be from dchinner@redhat.com are

queue-4.9/xfs-cancel-dirty-pages-on-invalidation.patch
queue-4.9/xfs-move-more-rt-specific-code-under-config_xfs_rt.patch
queue-4.9/xfs-don-t-change-inode-mode-if-acl-update-fails.patch
queue-4.9/xfs-trim-writepage-mapping-to-within-eof.patch
queue-4.9/xfs-don-t-log-uninitialised-fields-in-inode-structures.patch