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btrfs-progs: Import btrfs_insert/del/lookup_extref() functions. 

Import btrfs_insert/del/lookup_extref() functions form kernel for the
incoming btrfs_add_link() and btrfs_unlink() functions.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
master
Qu Wenruo 2014-12-03 12:18:28 +08:00 committed by David Sterba
parent 662d1dddca
commit 2606756577
2 changed files with 218 additions and 0 deletions
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13
ctree.h
View File

@ -2390,6 +2390,19 @@ int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root
int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path,
struct btrfs_key *location, int mod);
struct btrfs_inode_extref *btrfs_lookup_inode_extref(struct btrfs_trans_handle
*trans, struct btrfs_path *path, struct btrfs_root *root,
u64 ino, u64 parent_ino, u64 index, const char *name,
int namelen, int ins_len);
int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid,
u64 *index);
int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid, u64 index);
/* file-item.c */
int btrfs_del_csums(struct btrfs_trans_handle *trans,

205
inode-item.c
View File

@ -19,6 +19,7 @@
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "crc32c.h"
static int find_name_in_backref(struct btrfs_path *path, const char * name,
int name_len, struct btrfs_inode_ref **ref_ret)
@ -145,3 +146,207 @@ int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root
sizeof(*inode_item));
return ret;
}
static inline u64 btrfs_extref_hash(u64 parent_ino, const char *name,
int namelen)
{
return (u64)btrfs_crc32c(parent_ino, name, namelen);
}
static int btrfs_find_name_in_ext_backref(struct btrfs_path *path,
u64 parent_ino, const char *name, int namelen,
struct btrfs_inode_extref **extref_ret)
{
struct extent_buffer *node;
struct btrfs_inode_extref *extref;
unsigned long ptr;
unsigned long name_ptr;
u32 item_size;
u32 cur_offset = 0;
int ref_name_len;
int slot;
node = path->nodes[0];
slot = path->slots[0];
item_size = btrfs_item_size_nr(node, slot);
ptr = btrfs_item_ptr_offset(node, slot);
/*
* Search all extended backrefs in this item. We're only looking
* through any collisions so most of the time this is just going to
* compare against one buffer. If all is well, we'll return success and
* the inode ref object.
*/
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
name_ptr = (unsigned long)(&extref->name);
ref_name_len = btrfs_inode_extref_name_len(node, extref);
if (ref_name_len == namelen &&
btrfs_inode_extref_parent(node, extref) == parent_ino &&
(memcmp_extent_buffer(node, name, name_ptr, namelen) == 0))
{
if (extref_ret)
*extref_ret = extref;
return 1;
}
cur_offset += ref_name_len + sizeof(*extref);
}
return 0;
}
struct btrfs_inode_extref *btrfs_lookup_inode_extref(struct btrfs_trans_handle
*trans, struct btrfs_path *path, struct btrfs_root *root,
u64 ino, u64 parent_ino, u64 index, const char *name,
int namelen, int ins_len)
{
struct btrfs_key key;
struct btrfs_inode_extref *extref;
int ret = 0;
key.objectid = ino;
key.type = BTRFS_INODE_EXTREF_KEY;
key.offset = btrfs_extref_hash(parent_ino, name, namelen);
ret = btrfs_search_slot(trans, root, &key, path, ins_len,
ins_len ? 1 : 0);
if (ret < 0)
return ERR_PTR(ret);
if (ret > 0)
return NULL;
if (!btrfs_find_name_in_ext_backref(path, parent_ino, name,
namelen, &extref))
return NULL;
return extref;
}
int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid,
u64 *index)
{
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_inode_extref *extref;
struct extent_buffer *leaf;
int ret;
int del_len = name_len + sizeof(*extref);
unsigned long ptr;
unsigned long item_start;
u32 item_size;
key.objectid = inode_objectid;
key.type = BTRFS_INODE_EXTREF_KEY;
key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
if (ret < 0)
goto out;
/*
* Sanity check - did we find the right item for this name? This
* should always succeed so error here will make the FS readonly.
*/
if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
name, name_len, &extref)) {
ret = -ENOENT;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
if (index)
*index = btrfs_inode_extref_index(leaf, extref);
if (del_len == item_size) {
/*
* Common case only one ref in the item, remove the whole item.
*/
ret = btrfs_del_item(trans, root, path);
goto out;
}
ptr = (unsigned long)extref;
item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
memmove_extent_buffer(leaf, ptr, ptr + del_len,
item_size - (ptr + del_len - item_start));
btrfs_truncate_item(trans, root, path, item_size - del_len, 1);
out:
btrfs_free_path(path);
return ret;
}
/*
* btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
*
* The caller must have checked against BTRFS_LINK_MAX already.
*/
int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
u64 inode_objectid, u64 ref_objectid, u64 index)
{
struct btrfs_inode_extref *extref;
int ret;
int ins_len = name_len + sizeof(*extref);
unsigned long ptr;
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_item *item;
key.objectid = inode_objectid;
key.type = BTRFS_INODE_EXTREF_KEY;
key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_insert_empty_item(trans, root, path, &key,
ins_len);
if (ret == -EEXIST) {
if (btrfs_find_name_in_ext_backref(path, ref_objectid,
name, name_len, NULL))
goto out;
btrfs_extend_item(trans, root, path, ins_len);
ret = 0;
}
if (ret < 0)
goto out;
leaf = path->nodes[0];
item = btrfs_item_nr(path->slots[0]);
ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
ptr += btrfs_item_size(leaf, item) - ins_len;
extref = (struct btrfs_inode_extref *)ptr;
btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
btrfs_set_inode_extref_index(path->nodes[0], extref, index);
btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
ptr = (unsigned long)&extref->name;
write_extent_buffer(path->nodes[0], name, ptr, name_len);
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_free_path(path);
return ret;
}