Patch "btrfs: add write protection to SET_FEATURES ioctl" has been added to the 4.5-stable tree

This is a note to let you know that I've just added the patch titled

btrfs: add write protection to SET_FEATURES ioctl

to the 4.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
btrfs-add-write-protection-to-set_features-ioctl.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: David Sterba <[email protected]>
Date: Wed, 4 May 2016 11:32:00 +0200
Subject: btrfs: add write protection to SET_FEATURES ioctl

From: David Sterba <[email protected]>

commit 7ab19625a911f7568ec85302e3aa7a64186006c8 upstream.

Perform the want_write check if we get far enough to do any writes.

---
 fs/btrfs/ioctl.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

@@ -5397,9 +5397,15 @@ static int btrfs_ioctl_set_features(stru
 	if (ret)
 		return ret;
 
+	ret = mnt_want_write_file(file);
+	if (ret)
+		return ret;
+
 	trans = btrfs_start_transaction(root, 0);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		goto out_drop_write;
+	}
 
 	spin_lock(&root->fs_info->super_lock);
 	newflags = btrfs_super_compat_flags(super_block);

@@ -5418,7 +5424,11 @@ static int btrfs_ioctl_set_features(stru
 	btrfs_set_super_incompat_flags(super_block, newflags);
 	spin_unlock(&root->fs_info->super_lock);
 
-	return btrfs_commit_transaction(trans, root);
+	ret = btrfs_commit_transaction(trans, root);
+out_drop_write:
+	mnt_drop_write_file(file);
+
+	return ret;
 }
 
 long btrfs_ioctl(struct file *file, unsigned int

Patches currently in stable-queue which might be from [email protected] are

queue-4.5/btrfs-add-read-only-check-to-sysfs-handler-of-features.patch queue-4.5/btrfs-add-write-protection-to-set_features-ioctl.patch