[ 46/60] ext4: fix mount/remount error messages for incompatible mount options

From: Greg Kroah-Hartman
Date: Tue Aug 13 2013 - 02:45:20 EST

3.10-stable review patch. If anyone has any objections, please let me know.


From: Piotr Sarna <p.sarna@xxxxxxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxxx>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

fs/ext4/super.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3445,7 +3445,7 @@ static int ext4_fill_super(struct super_
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_blo
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");

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