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authorDavid Sterba <dsterba@suse.cz>2016-05-04 11:32:00 +0200
committerDavid Sterba <dsterba@suse.com>2016-05-06 15:22:49 +0200
commit7ab19625a911f7568ec85302e3aa7a64186006c8 (patch)
tree2745e636072f4e01263034a77bb434ee93afbb4d /fs/btrfs
parent48b3b9d401ec86899a52003b37331190a35a81a6 (diff)
downloadlinux-7ab19625a911f7568ec85302e3aa7a64186006c8.tar.bz2
btrfs: add write protection to SET_FEATURES ioctl
Perform the want_write check if we get far enough to do any writes. Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/ioctl.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 798f58e7338e..1e8ce5247a81 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -5406,9 +5406,15 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
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);
@@ -5427,7 +5433,11 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
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