[PATCH] ext4: compare old and new mode before setting update_mode flag

[PATCH] ext4: compare old and new mode before setting update_mode flag

[Chengguang Xu]

If new mode is the same as old mode we don't have to reset
inode mode in the rest of the code, so compare old and new
mode before setting update_mode flag.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
---
 fs/ext4/acl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index c1d570ee1d9f..8c7bbf3e566d 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -248,7 +248,8 @@ ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 		error = posix_acl_update_mode(inode, &mode, &acl);
 		if (error)
 			goto out_stop;
-		update_mode = 1;
+		if (mode != inode->i_mode)
+			update_mode = 1;
 	}
 
 	error = __ext4_set_acl(handle, inode, type, acl, 0 /* xattr_flags */);
-- 
2.17.2

Re: [PATCH] ext4: compare old and new mode before setting update_mode flag

[Theodore Y. Ts'o]

On Sat, Nov 17, 2018 at 05:01:52PM +0800, Chengguang Xu wrote:
> If new mode is the same as old mode we don't have to reset
> inode mode in the rest of the code, so compare old and new
> mode before setting update_mode flag.
> 
> Signed-off-by: Chengguang Xu <cgxu519@gmx.com>

Thanks, applied.

I know Jan declined the equivalent patch for ext2; but it doesn't add
_that_ much extra complexity, and ext4_mark_inode_dirty() is rather
more heavyweight than ext2_mark_inode_dirty().

						- Ted