vfs: create a generic checking and prep function for FS_IOC_SETFLAGS

Create a generic function to check incoming FS_IOC_SETFLAGS flag values
and later prepare the inode for updates so that we can standardize the
implementations that follow ext4's flag values.

Note that the efivarfs implementation no longer fails a no-op SETFLAGS
without CAP_LINUX_IMMUTABLE since that's the behavior in ext*.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>

1 files changed, 3 insertions, 10 deletions

diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c
index 4f1a397fda69..034ad14710d1 100644
--- a/fs/ubifs/ioctl.c
+++ b/fs/ubifs/ioctl.c
@@ -107,18 +107,11 @@ static int setflags(struct inode *inode, int flags)
 	if (err)
 		return err;
 
-	/*
-	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
-	 * the relevant capability.
-	 */
 	mutex_lock(&ui->ui_mutex);
 	oldflags = ubifs2ioctl(ui->flags);
-	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
-		if (!capable(CAP_LINUX_IMMUTABLE)) {
-			err = -EPERM;
-			goto out_unlock;
-		}
-	}
+	err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
+	if (err)
+		goto out_unlock;
 
 	ui->flags = ioctl2ubifs(flags);
 	ubifs_set_inode_flags(inode);