[PATCH SRU T/V/X] btrfs: bugfix: handle FS_IOC32_{GETFLAGS, SETFLAGS, GETVERSION} in btrfs_ioctl

[Tim Gardner]

From: Luke Dashjr <luke at dashjr.org>

BugLink: http://bugs.launchpad.net/bugs/1619918

32-bit ioctl uses these rather than the regular FS_IOC_* versions. They can
be handled in btrfs using the same code. Without this, 32-bit {ch,ls}attr
fail.

Signed-off-by: Luke Dashjr <luke-jr+git at utopios.org>
Cc: stable at vger.kernel.org
Reviewed-by: Josef Bacik <jbacik at fb.com>
Reviewed-by: David Sterba <dsterba at suse.com>
Signed-off-by: David Sterba <dsterba at suse.com>
(back ported from commit 4c63c2454eff996c5e27991221106eb511f7db38)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>

 Conflicts:
	fs/btrfs/ctree.h
---
 fs/btrfs/ctree.h |  1 +
 fs/btrfs/file.c  |  2 +-
 fs/btrfs/inode.c |  2 +-
 fs/btrfs/ioctl.c | 21 +++++++++++++++++++++
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 385b449..0103049 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -4014,6 +4014,7 @@ void btrfs_test_inode_set_ops(struct inode *inode);
 
 /* ioctl.c */
 long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 void btrfs_update_iflags(struct inode *inode);
 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir);
 int btrfs_is_empty_uuid(u8 *uuid);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 353f4ba..5db4fb9 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2929,7 +2929,7 @@ const struct file_operations btrfs_file_operations = {
 	.fallocate	= btrfs_fallocate,
 	.unlocked_ioctl	= btrfs_ioctl,
 #ifdef CONFIG_COMPAT
-	.compat_ioctl	= btrfs_ioctl,
+	.compat_ioctl	= btrfs_compat_ioctl,
 #endif
 };
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4bc9dbf..e867fca 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10044,7 +10044,7 @@ static const struct file_operations btrfs_dir_file_operations = {
 	.iterate	= btrfs_real_readdir,
 	.unlocked_ioctl	= btrfs_ioctl,
 #ifdef CONFIG_COMPAT
-	.compat_ioctl	= btrfs_ioctl,
+	.compat_ioctl	= btrfs_compat_ioctl,
 #endif
 	.release        = btrfs_release_file,
 	.fsync		= btrfs_sync_file,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index bfcd87e..0a5eddc 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -5657,3 +5657,24 @@ long btrfs_ioctl(struct file *file, unsigned int
 
 	return -ENOTTY;
 }
+
+#ifdef CONFIG_COMPAT
+long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case FS_IOC32_GETFLAGS:
+		cmd = FS_IOC_GETFLAGS;
+		break;
+	case FS_IOC32_SETFLAGS:
+		cmd = FS_IOC_SETFLAGS;
+		break;
+	case FS_IOC32_GETVERSION:
+		cmd = FS_IOC_GETVERSION;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif
-- 
2.7.4