From ef3b9af50bfa6a1f02cd7b3f5124b712b1ba3e3c Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Sun, 27 Apr 2014 20:40:45 +0100 Subject: [PATCH] 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: Filipe David Borba Manana Signed-off-by: Chris Mason Reviewed-by: David Sterba --- fs/btrfs/inode.c | 118 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 98 insertions(+), 20 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 24dfa27a4f76..5c0def8dd761 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -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, @@ -5605,21 +5608,24 @@ 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; - /* - * Start new inodes with an inode_ref. This is slightly more - * efficient for small numbers of hard links since they will - * be packed into one item. Extended refs will kick in if we - * add more hard links than can fit in the ref item. - */ - key[1].objectid = objectid; - 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); + + if (name) { + /* + * Start new inodes with an inode_ref. This is slightly more + * efficient for small numbers of hard links since they will + * be packed into one item. Extended refs will kick in if we + * add more hard links than can fit in the ref item. + */ + key[1].objectid = objectid; + btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY); + key[1].offset = ref_objectid; + + 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); - 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); + 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, -- 2.20.1