| From: Jeff Mahoney <jeffm@suse.com> |
| Date: Mon, 6 Feb 2017 19:39:09 -0500 |
| Subject: 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: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| fs/btrfs/ioctl.c | 6 ++++-- |
| 1 file changed, 4 insertions(+), 2 deletions(-) |
| |
| --- a/fs/btrfs/ioctl.c |
| +++ b/fs/btrfs/ioctl.c |
| @@ -3276,6 +3276,10 @@ long btrfs_ioctl(struct file *file, unsi |
| #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; |
| @@ -3286,8 +3290,6 @@ long btrfs_compat_ioctl(struct file *fil |
| case FS_IOC32_GETVERSION: |
| cmd = FS_IOC_GETVERSION; |
| break; |
| - default: |
| - return -ENOIOCTLCMD; |
| } |
| |
| return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg)); |
