Commit 2a362249 authored Feb 06, 2017 by Jeff Mahoney Committed by David Sterba Feb 08, 2017

btrfs: fix btrfs_compat_ioctl failures on non-compat ioctls



Commit 4c63c245 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: 4c63c245 ("btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl")
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 57b59ed2

fs/btrfs/ioctl.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -5665,6 +5665,10 @@ 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;
		@@ -5675,8 +5679,6 @@ 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));

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