btrfs-progs: Add btrfs_unlink() and btrfs_add_link() functions.

Add btrfs_unlink() and btrfs_add_link() functions in inode.c,
for the incoming btrfs_mkdir() and later inode operations functions.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
master
Qu Wenruo 2014-12-03 12:18:30 +08:00 committed by David Sterba
parent ed3a206c8f
commit 0cc75eddd0
4 changed files with 449 additions and 7 deletions

View File

@ -10,7 +10,8 @@ objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
root-tree.o dir-item.o file-item.o inode-item.o inode-map.o \
extent-cache.o extent_io.o volumes.o utils.o repair.o \
qgroup.o raid6.o free-space-cache.o list_sort.o props.o \
ulist.o qgroup-verify.o backref.o string-table.o task-utils.o
ulist.o qgroup-verify.o backref.o string-table.o task-utils.o \
inode.o
cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \
cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \
cmds-quota.o cmds-qgroup.o cmds-replace.o cmds-check.o \

View File

@ -1599,14 +1599,9 @@ static int repair_inode_orphan_item(struct btrfs_trans_handle *trans,
struct btrfs_path *path,
struct inode_record *rec)
{
struct btrfs_key key;
int ret;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = rec->ino;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
ret = btrfs_add_orphan_item(trans, root, path, rec->ino);
btrfs_release_path(path);
if (!ret)
rec->errors &= ~I_ERR_NO_ORPHAN_ITEM;

13
ctree.h
View File

@ -2441,4 +2441,17 @@ static inline int is_fstree(u64 rootid)
return 1;
return 0;
}
/* inode.c */
int check_dir_conflict(struct btrfs_root *root, char *name, int namelen,
u64 dir, u64 index);
int btrfs_add_link(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 ino, u64 parent_ino, char *name, int namelen,
u8 type, u64 *index, int add_backref);
int btrfs_unlink(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 ino, u64 parent_ino, u64 index, const char *name,
int namelen, int add_orphan);
int btrfs_add_orphan_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_path *path,
u64 ino);
#endif

433
inode.c 100644
View File

@ -0,0 +1,433 @@
/*
* Copyright (C) 2014 Fujitsu. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
/*
* Unlike inode.c in kernel, which can use most of the kernel infrastructure
* like inode/dentry things, in user-land, we can only use inode number to
* do directly operation on extent buffer, which may cause extra searching,
* but should not be a huge problem since progs is less performence sensitive.
*/
#include <sys/stat.h>
#include "ctree.h"
#include "transaction.h"
#include "disk-io.h"
#include "time.h"
/*
* Find a free inode index for later btrfs_add_link().
* Currently just search from the largest dir_index and +1.
*/
static int btrfs_find_free_dir_index(struct btrfs_root *root, u64 dir_ino,
u64 *ret_ino)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_key found_key;
u64 ret_val = 2;
int ret = 0;
if (!ret_ino)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = dir_ino;
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
ret = 0;
if (path->slots[0] == 0) {
ret = btrfs_prev_leaf(root, path);
if (ret < 0)
goto out;
if (ret > 0) {
/*
* This shouldn't happen since there must be a leaf
* containing the DIR_ITEM.
* Can only happen when the previous leaf is corrupted.
*/
ret = -EIO;
goto out;
}
} else {
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
if (found_key.objectid != dir_ino ||
found_key.type != BTRFS_DIR_INDEX_KEY)
goto out;
ret_val = found_key.offset + 1;
out:
btrfs_free_path(path);
if (ret == 0)
*ret_ino = ret_val;
return ret;
}
/* Check the dir_item/index conflicts before insert */
int check_dir_conflict(struct btrfs_root *root, char *name, int namelen,
u64 dir, u64 index)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_inode_item *inode_item;
struct btrfs_dir_item *dir_item;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/* Given dir exists? */
key.objectid = dir;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
/* Is it a dir? */
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
if (!(btrfs_inode_mode(path->nodes[0], inode_item) & S_IFDIR)) {
ret = -ENOTDIR;
goto out;
}
btrfs_release_path(path);
/* Name conflicting? */
dir_item = btrfs_lookup_dir_item(NULL, root, path, dir, name,
namelen, 0);
if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
if (dir_item) {
ret = -EEXIST;
goto out;
}
btrfs_release_path(path);
/* Index conflicting? */
dir_item = btrfs_lookup_dir_index(NULL, root, path, dir, name,
namelen, index, 0);
if (IS_ERR(dir_item) && PTR_ERR(dir_item) == -ENOENT)
dir_item = NULL;
if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
if (dir_item) {
ret = -EEXIST;
goto out;
}
out:
btrfs_free_path(path);
return ret;
}
/*
* Add dir_item/index for 'parent_ino' if add_backref is true, also insert a
* backref from the ino to parent dir and update the nlink(Kernel version does
* not do this thing)
*
* Currently only supports adding link from an inode to another inode.
*/
int btrfs_add_link(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 ino, u64 parent_ino, char *name, int namelen,
u8 type, u64 *index, int add_backref)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_inode_item *inode_item;
u32 nlink;
u64 inode_size;
u64 ret_index = 0;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (index && *index) {
ret_index = *index;
} else {
ret = btrfs_find_free_dir_index(root, parent_ino, &ret_index);
if (ret < 0)
goto out;
}
ret = check_dir_conflict(root, name, namelen, parent_ino, ret_index);
if (ret < 0)
goto out;
/* Add inode ref */
if (add_backref) {
ret = btrfs_insert_inode_ref(trans, root, name, namelen,
ino, parent_ino, ret_index);
if (ret < 0)
goto out;
/* Update nlinks for the inode */
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto out;
}
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
nlink = btrfs_inode_nlink(path->nodes[0], inode_item);
nlink++;
btrfs_set_inode_nlink(path->nodes[0], inode_item, nlink);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
}
/* Add dir_item and dir_index */
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_insert_dir_item(trans, root, name, namelen, parent_ino,
&key, type, ret_index);
if (ret < 0)
goto out;
/* Update inode size of the parent inode */
key.objectid = parent_ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
if (ret)
goto out;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
inode_size = btrfs_inode_size(path->nodes[0], inode_item);
inode_size += namelen * 2;
btrfs_set_inode_size(path->nodes[0], inode_item, inode_size);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
out:
btrfs_free_path(path);
if (ret == 0 && index)
*index = ret_index;
return ret;
}
int btrfs_add_orphan_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_path *path,
u64 ino)
{
struct btrfs_key key;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = ino;
return btrfs_insert_empty_item(trans, root, path, &key, 0);
}
/*
* Unlink an inode, which will remove its backref and corresponding dir_index/
* dir_item if any of them exists.
*
* If an inode's nlink is reduced to 0 and 'add_orphan' is true, it will be
* added to orphan inode and wairing to be deleted by next kernel mount.
*/
int btrfs_unlink(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 ino, u64 parent_ino, u64 index, const char *name,
int namelen, int add_orphan)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_inode_item *inode_item;
struct btrfs_inode_ref *inode_ref;
struct btrfs_dir_item *dir_item;
u64 inode_size;
u32 nlinks;
int del_inode_ref = 0;
int del_dir_item = 0;
int del_dir_index = 0;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/* check the ref and backref exists */
inode_ref = btrfs_lookup_inode_ref(trans, root, path, name, namelen,
ino, parent_ino, index, 0);
if (IS_ERR(inode_ref)) {
ret = PTR_ERR(inode_ref);
goto out;
}
if (inode_ref)
del_inode_ref = 1;
btrfs_release_path(path);
dir_item = btrfs_lookup_dir_item(NULL, root, path, parent_ino,
name, namelen, 0);
if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
if (dir_item)
del_dir_item = 1;
btrfs_release_path(path);
dir_item = btrfs_lookup_dir_index(NULL, root, path, parent_ino,
name, namelen, index, 0);
/*
* Since lookup_dir_index() will return -ENOENT when not found,
* we need to do extra check.
*/
if (IS_ERR(dir_item) && PTR_ERR(dir_item) == -ENOENT)
dir_item = NULL;
if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
if (dir_item)
del_dir_index = 1;
btrfs_release_path(path);
if (!del_inode_ref && !del_dir_item && !del_dir_index) {
/* All not found, shouldn't happen */
ret = -ENOENT;
goto out;
}
if (del_inode_ref) {
/* Only decrease nlink when deleting inode_ref */
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto out;
}
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
nlinks = btrfs_inode_nlink(path->nodes[0], inode_item);
if (nlinks > 0)
nlinks--;
btrfs_set_inode_nlink(path->nodes[0], inode_item, nlinks);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
/* For nlinks == 0, add it to orphan list if needed */
if (nlinks == 0 && add_orphan) {
ret = btrfs_add_orphan_item(trans, root, path, ino);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
}
ret = btrfs_del_inode_ref(trans, root, name, namelen, ino,
parent_ino, &index);
if (ret < 0)
goto out;
}
if (del_dir_index) {
dir_item = btrfs_lookup_dir_index(trans, root, path,
parent_ino, name, namelen,
index, -1);
if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
if (!dir_item) {
ret = -ENOENT;
goto out;
}
ret = btrfs_delete_one_dir_name(trans, root, path, dir_item);
if (ret)
goto out;
btrfs_release_path(path);
/* Update inode size of the parent inode */
key.objectid = parent_ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
if (ret)
goto out;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
inode_size = btrfs_inode_size(path->nodes[0], inode_item);
if (inode_size >= namelen)
inode_size -= namelen;
btrfs_set_inode_size(path->nodes[0], inode_item, inode_size);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
}
if (del_dir_item) {
dir_item = btrfs_lookup_dir_item(trans, root, path, parent_ino,
name, namelen, -1);
if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
if (!dir_item) {
ret = -ENOENT;
goto out;
}
ret = btrfs_delete_one_dir_name(trans, root, path, dir_item);
if (ret < 0)
goto out;
btrfs_release_path(path);
/* Update inode size of the parent inode */
key.objectid = parent_ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
if (ret)
goto out;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
inode_size = btrfs_inode_size(path->nodes[0], inode_item);
if (inode_size >= namelen)
inode_size -= namelen;
btrfs_set_inode_size(path->nodes[0], inode_item, inode_size);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
}
out:
btrfs_free_path(path);
return ret;
}