Commit 8546b570 authored by David Sterba's avatar David Sterba
Browse files

btrfs: preallocate path for snapshot creation at ioctl time 



We can also preallocate btrfs_path that's used during pending snapshot
creation and avoid another late ENOMEM failure.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent b0c0ea63

fs/btrfs/ioctl.c

+3 −1
Original line number Diff line number Diff line
@@ -661,7 +661,8 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, 


	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),

			GFP_NOFS);

	if (!pending_snapshot->root_item) {

	pending_snapshot->path = btrfs_alloc_path();

	if (!pending_snapshot->root_item || !pending_snapshot->path) {

		ret = -ENOMEM;

		goto free_pending;

	}
@@ -747,6 +748,7 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, 
		wake_up_atomic_t(&root->will_be_snapshoted);

free_pending:

	kfree(pending_snapshot->root_item);

	btrfs_free_path(pending_snapshot->path);

	kfree(pending_snapshot);



	return ret;

fs/btrfs/transaction.c

+4 −5
Original line number Diff line number Diff line
@@ -1319,11 +1319,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
	u64 root_flags;

	uuid_le new_uuid;



	path = btrfs_alloc_path();

	if (!path) {

		pending->error = -ENOMEM;

		return 0;

	}

	ASSERT(pending->path);

	path = pending->path;



	ASSERT(pending->root_item);

	new_root_item = pending->root_item;
@@ -1561,6 +1558,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
	kfree(new_root_item);

	pending->root_item = NULL;

	btrfs_free_path(path);

	pending->path = NULL;



	return ret;

}

fs/btrfs/transaction.h

+1 −0
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ struct btrfs_pending_snapshot { 
	struct btrfs_root_item *root_item;

	struct btrfs_root *snap;

	struct btrfs_qgroup_inherit *inherit;

	struct btrfs_path *path;

	/* block reservation for the operation */

	struct btrfs_block_rsv block_rsv;

	u64 qgroup_reserved;