btrfs: fix btrfs_compat_ioctl failures on non-compat ioctls

commit 2a362249187a8d0f6d942d6e1d763d150a296f47 upstream.

Commit 4c63c2454ef incorrectly assumed that returning -ENOIOCTLCMD would
cause the native ioctl to be called.  The ->compat_ioctl callback is
expected to handle all ioctls, not just compat variants.  As a result,
when using 32-bit userspace on 64-bit kernels, everything except those
three ioctls would return -ENOTTY.

Fixes: 4c63c2454ef ("btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl")
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7acbd2cf6192..1782804f6c26 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -5648,6 +5648,10 @@ long btrfs_ioctl(struct file *file, unsigned int
 #ifdef CONFIG_COMPAT
 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
+        /*
+         * These all access 32-bit values anyway so no further
+         * handling is necessary.
+         */
         switch (cmd) {
         case FS_IOC32_GETFLAGS:
                 cmd = FS_IOC_GETFLAGS;
@@ -5658,8 +5662,6 @@ long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         case FS_IOC32_GETVERSION:
                 cmd = FS_IOC_GETVERSION;
                 break;
-        default:
-                return -ENOIOCTLCMD;
         }
 
         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));