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Commit ef3b9af5 authored by Filipe Manana's avatar Filipe Manana Committed by Chris Mason
Browse files

Btrfs: implement inode_operations callback tmpfile 



This implements the tmpfile callback of struct inode_operations, introduced
in the linux kernel 3.11, and implemented already by some filesystems. This
callback is invoked by the VFS when the flag O_TMPFILE is passed to the open
system call.

Signed-off-by: default avatarFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.cz>
parent e4ef90ff

fs/btrfs/inode.c

+98 −20
Original line number Diff line number Diff line
@@ -5553,6 +5553,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 
	struct btrfs_inode_ref *ref;

	struct btrfs_key key[2];

	u32 sizes[2];

	int nitems = name ? 2 : 1;

	unsigned long ptr;

	int ret;
@@ -5572,7 +5573,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 
	 */

	inode->i_ino = objectid;



	if (dir) {

	if (dir && name) {

		trace_btrfs_inode_request(dir);



		ret = btrfs_set_inode_index(dir, index);
@@ -5581,6 +5582,8 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 
			iput(inode);

			return ERR_PTR(ret);

		}

	} else if (dir) {

		*index = 0;

	}

	/*

	 * index_cnt is ignored for everything but a dir,
@@ -5605,6 +5608,9 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 
	btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);

	key[0].offset = 0;



	sizes[0] = sizeof(struct btrfs_inode_item);



	if (name) {

		/*

		 * Start new inodes with an inode_ref. This is slightly more

		 * efficient for small numbers of hard links since they will
@@ -5615,11 +5621,11 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 
		btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);

		key[1].offset = ref_objectid;



	sizes[0] = sizeof(struct btrfs_inode_item);

		sizes[1] = name_len + sizeof(*ref);

	}



	path->leave_spinning = 1;

	ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);

	ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);

	if (ret != 0)

		goto fail;
@@ -5632,12 +5638,14 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 
			     sizeof(*inode_item));

	fill_inode_item(trans, path->nodes[0], inode_item, inode);



	if (name) {

		ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,

				     struct btrfs_inode_ref);

		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);

		btrfs_set_inode_ref_index(path->nodes[0], ref, *index);

		ptr = (unsigned long)(ref + 1);

		write_extent_buffer(path->nodes[0], name, ptr, name_len);

	}



	btrfs_mark_buffer_dirty(path->nodes[0]);

	btrfs_free_path(path);
@@ -5673,7 +5681,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 


	return inode;

fail:

	if (dir)

	if (dir && name)

		BTRFS_I(dir)->index_cnt--;

	btrfs_free_path(path);

	iput(inode);
@@ -5958,6 +5966,15 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 
		err = btrfs_update_inode(trans, root, inode);

		if (err)

			goto fail;

		if (inode->i_nlink == 1) {

			/*

			 * If new hard link count is 1, it's a file created

			 * with open(2) O_TMPFILE flag.

			 */

			err = btrfs_orphan_del(trans, inode);

			if (err)

				goto fail;

		}

		d_instantiate(dentry, inode);

		btrfs_log_new_name(trans, inode, NULL, parent);

	}
@@ -8884,6 +8901,66 @@ static int btrfs_permission(struct inode *inode, int mask) 
	return generic_permission(inode, mask);

}



static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)

{

	struct btrfs_trans_handle *trans;

	struct btrfs_root *root = BTRFS_I(dir)->root;

	struct inode *inode = NULL;

	u64 objectid;

	u64 index;

	int ret = 0;



	/*

	 * 5 units required for adding orphan entry

	 */

	trans = btrfs_start_transaction(root, 5);

	if (IS_ERR(trans))

		return PTR_ERR(trans);



	ret = btrfs_find_free_ino(root, &objectid);

	if (ret)

		goto out;



	inode = btrfs_new_inode(trans, root, dir, NULL, 0,

				btrfs_ino(dir), objectid, mode, &index);

	if (IS_ERR(inode)) {

		ret = PTR_ERR(inode);

		inode = NULL;

		goto out;

	}



	ret = btrfs_init_inode_security(trans, inode, dir, NULL);

	if (ret)

		goto out;



	ret = btrfs_update_inode(trans, root, inode);

	if (ret)

		goto out;



	inode->i_fop = &btrfs_file_operations;

	inode->i_op = &btrfs_file_inode_operations;



	inode->i_mapping->a_ops = &btrfs_aops;

	inode->i_mapping->backing_dev_info = &root->fs_info->bdi;

	BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;



	ret = btrfs_orphan_add(trans, inode);

	if (ret)

		goto out;



	d_tmpfile(dentry, inode);

	mark_inode_dirty(inode);



out:

	btrfs_end_transaction(trans, root);

	if (ret)

		iput(inode);

	btrfs_balance_delayed_items(root);

	btrfs_btree_balance_dirty(root);



	return ret;

}



static const struct inode_operations btrfs_dir_inode_operations = {

	.getattr	= btrfs_getattr,

	.lookup		= btrfs_lookup,
@@ -8904,6 +8981,7 @@ static const struct inode_operations btrfs_dir_inode_operations = { 
	.get_acl	= btrfs_get_acl,

	.set_acl	= btrfs_set_acl,

	.update_time	= btrfs_update_time,

	.tmpfile        = btrfs_tmpfile,

};

static const struct inode_operations btrfs_dir_ro_inode_operations = {

	.lookup		= btrfs_lookup,