1 files changed, 20 insertions, 21 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ac37040..6225433 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -323,7 +323,7 @@ static noinline int create_subvol(struct btrfs_root *root,
 	struct btrfs_inode_item *inode_item;
 	struct extent_buffer *leaf;
 	struct btrfs_root *new_root;
-	struct dentry *parent = dget_parent(dentry);
+	struct dentry *parent = dentry->d_parent;
 	struct inode *dir;
 	int ret;
 	int err;
@@ -332,10 +332,8 @@ static noinline int create_subvol(struct btrfs_root *root,
 	u64 index = 0;
 
 	ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
-	if (ret) {
-		dput(parent);
+	if (ret)
 		return ret;
-	}
 
 	dir = parent->d_inode;
 
@@ -346,10 +344,8 @@ static noinline int create_subvol(struct btrfs_root *root,
 	 * 2 - dir items
 	 */
 	trans = btrfs_start_transaction(root, 6);
-	if (IS_ERR(trans)) {
-		dput(parent);
+	if (IS_ERR(trans))
 		return PTR_ERR(trans);
-	}
 
 	leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 				      0, objectid, NULL, 0, 0, 0);
@@ -439,7 +435,6 @@ static noinline int create_subvol(struct btrfs_root *root,
 
 	d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 fail:
-	dput(parent);
 	if (async_transid) {
 		*async_transid = trans->transid;
 		err = btrfs_commit_transaction_async(trans, root, 1);
@@ -456,7 +451,6 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 			   bool readonly)
 {
 	struct inode *inode;
-	struct dentry *parent;
 	struct btrfs_pending_snapshot *pending_snapshot;
 	struct btrfs_trans_handle *trans;
 	int ret;
@@ -482,8 +476,10 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 	ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
 	BUG_ON(ret);
 
+	spin_lock(&root->fs_info->trans_lock);
 	list_add(&pending_snapshot->list,
 		 &trans->transaction->pending_snapshots);
+	spin_unlock(&root->fs_info->trans_lock);
 	if (async_transid) {
 		*async_transid = trans->transid;
 		ret = btrfs_commit_transaction_async(trans,
@@ -502,9 +498,7 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 	if (ret)
 		goto fail;
 
-	parent = dget_parent(dentry);
-	inode = btrfs_lookup_dentry(parent->d_inode, dentry);
-	dput(parent);
+	inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 	if (IS_ERR(inode)) {
 		ret = PTR_ERR(inode);
 		goto fail;
@@ -2054,29 +2048,34 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
 
 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
 {
-	struct btrfs_ioctl_fs_info_args fi_args;
+	struct btrfs_ioctl_fs_info_args *fi_args;
 	struct btrfs_device *device;
 	struct btrfs_device *next;
 	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+	int ret = 0;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	fi_args.num_devices = fs_devices->num_devices;
-	fi_args.max_id = 0;
-	memcpy(&fi_args.fsid, root->fs_info->fsid, sizeof(fi_args.fsid));
+	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
+	if (!fi_args)
+		return -ENOMEM;
+
+	fi_args->num_devices = fs_devices->num_devices;
+	memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
 
 	mutex_lock(&fs_devices->device_list_mutex);
 	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
-		if (device->devid > fi_args.max_id)
-			fi_args.max_id = device->devid;
+		if (device->devid > fi_args->max_id)
+			fi_args->max_id = device->devid;
 	}
 	mutex_unlock(&fs_devices->device_list_mutex);
 
-	if (copy_to_user(arg, &fi_args, sizeof(fi_args)))
-		return -EFAULT;
+	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
+		ret = -EFAULT;
 
-	return 0;
+	kfree(fi_args);
+	return ret;
 }
 
 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)