ext4: fix mount/remount error messages for incompatible mount options

commit 6ae6514b33f941d3386da0dfbe2942766eab1577 upstream.

Commit 5688978 ("ext4: improve handling of conflicting mount options")
introduced incorrect messages shown while choosing wrong mount options.

First of all, both cases of incorrect mount options,
"data=journal,delalloc" and "data=journal,dioread_nolock" result in
the same error message.

Secondly, the problem above isn't solved for remount option: the
mismatched parameter is simply ignored.  Moreover, ext4_msg states
that remount with options "data=journal,delalloc" succeeded, which is
not true.

To fix it up, I added a simple check after parse_options() call to
ensure that data=journal and delalloc/dioread_nolock parameters are
not present at the same time.

Signed-off-by: Piotr Sarna <p.sarna@partner.samsung.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 16 insertions, 1 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3c2bf0c4c1e0..3f7c39e6d097 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3445,7 +3445,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                 }
                 if (test_opt(sb, DIOREAD_NOLOCK)) {
                         ext4_msg(sb, KERN_ERR, "can't mount with "
-                                 "both data=journal and delalloc");
+                                 "both data=journal and dioread_nolock");
                         goto failed_mount;
                 }
                 if (test_opt(sb, DELALLOC))
@@ -4646,6 +4646,21 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
                 goto restore_opts;
         }
 
+        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
+                if (test_opt2(sb, EXPLICIT_DELALLOC)) {
+                        ext4_msg(sb, KERN_ERR, "can't mount with "
+                                 "both data=journal and delalloc");
+                        err = -EINVAL;
+                        goto restore_opts;
+                }
+                if (test_opt(sb, DIOREAD_NOLOCK)) {
+                        ext4_msg(sb, KERN_ERR, "can't mount with "
+                                 "both data=journal and dioread_nolock");
+                        err = -EINVAL;
+                        goto restore_opts;
+                }
+        }
+
         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
                 ext4_abort(sb, "Abort forced by user");