Btrfs: Add back pointers from the inode to the directory that references it
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index cb1b156..035fa15 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -53,7 +53,7 @@
#define BTRFS_CSUM_SIZE 32
/* four bytes for CRC32 */
#define BTRFS_CRC32_SIZE 4
-#define BTRFS_EMPTY_DIR_SIZE 6
+#define BTRFS_EMPTY_DIR_SIZE 0
#define BTRFS_FT_UNKNOWN 0
#define BTRFS_FT_REG_FILE 1
@@ -206,6 +206,11 @@
__le64 offset;
} __attribute__ ((__packed__));
+struct btrfs_inode_ref {
+ __le16 name_len;
+ /* name goes here */
+} __attribute__ ((__packed__));
+
struct btrfs_inode_timespec {
__le64 sec;
__le32 nsec;
@@ -379,7 +384,8 @@
* the FS
*/
#define BTRFS_INODE_ITEM_KEY 1
-#define BTRFS_XATTR_ITEM_KEY 2
+#define BTRFS_INODE_REF_KEY 2
+#define BTRFS_XATTR_ITEM_KEY 8
/* reserve 2-15 close to the inode for later flexibility */
/*
@@ -486,6 +492,9 @@
BTRFS_SETGET_FUNCS(disk_block_group_used, struct btrfs_block_group_item,
used, 64);
+/* struct btrfs_inode_ref */
+BTRFS_SETGET_FUNCS(inode_ref_name_len, struct btrfs_inode_ref, name_len, 16);
+
/* struct btrfs_inode_item */
BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64);
BTRFS_SETGET_FUNCS(inode_size, struct btrfs_inode_item, size, 64);
@@ -1043,6 +1052,14 @@
int btrfs_find_highest_inode(struct btrfs_root *fs_root, u64 *objectid);
/* inode-item.c */
+int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid);
+int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid);
int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid);
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 35d2608..cba30b6 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -20,6 +20,142 @@
#include "disk-io.h"
#include "transaction.h"
+int find_name_in_backref(struct btrfs_path *path, const char * name,
+ int name_len, struct btrfs_inode_ref **ref_ret)
+{
+ struct extent_buffer *leaf;
+ struct btrfs_inode_ref *ref;
+ unsigned long ptr;
+ unsigned long name_ptr;
+ u32 item_size;
+ u32 cur_offset = 0;
+ int len;
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ while (cur_offset < item_size) {
+ ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
+ len = btrfs_inode_ref_name_len(leaf, ref);
+ name_ptr = (unsigned long)(ref + 1);
+ cur_offset += len + sizeof(*ref);
+ if (len != name_len)
+ continue;
+ if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
+ *ref_ret = ref;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_inode_ref *ref;
+ struct extent_buffer *leaf;
+ unsigned long ptr;
+ unsigned long item_start;
+ u32 item_size;
+ u32 sub_item_len;
+ int ret;
+ int del_len = name_len + sizeof(*ref);
+
+ key.objectid = inode_objectid;
+ key.offset = ref_objectid;
+ btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0) {
+ ret = -ENOENT;
+ goto out;
+ } else if (ret < 0) {
+ goto out;
+ }
+ if (!find_name_in_backref(path, name, name_len, &ref)) {
+ ret = -ENOENT;
+ goto out;
+ }
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+ if (del_len == item_size) {
+ ret = btrfs_del_item(trans, root, path);
+ goto out;
+ }
+ ptr = (unsigned long)ref;
+ sub_item_len = name_len + sizeof(*ref);
+ item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
+ item_size - (ptr + sub_item_len - item_start));
+ ret = btrfs_truncate_item(trans, root, path,
+ item_size - sub_item_len, 1);
+ BUG_ON(ret);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_inode_ref *ref;
+ unsigned long ptr;
+ int ret;
+ int ins_len = name_len + sizeof(*ref);
+
+ key.objectid = inode_objectid;
+ key.offset = ref_objectid;
+ btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ ins_len);
+ if (ret == -EEXIST) {
+ u32 old_size;
+
+ if (find_name_in_backref(path, name, name_len, &ref))
+ goto out;
+
+ old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
+ ret = btrfs_extend_item(trans, root, path, ins_len);
+ BUG_ON(ret);
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_ref);
+ ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
+ btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+ ptr = (unsigned long)(ref + 1);
+ ret = 0;
+ } else if (ret < 0) {
+ goto out;
+ } else {
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_ref);
+ btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+ ptr = (unsigned long)(ref + 1);
+ }
+ write_extent_buffer(path->nodes[0], name, ptr, name_len);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 03fea03..cefe740 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -404,6 +404,17 @@
ret = btrfs_delete_one_dir_name(trans, root, path, di);
dentry->d_inode->i_ctime = dir->i_ctime;
+ if (!S_ISLNK(dentry->d_inode->i_mode)) {
+ ret = btrfs_del_inode_ref(trans, root, name, name_len,
+ dentry->d_inode->i_ino,
+ dentry->d_parent->d_inode->i_ino);
+ if (ret) {
+ printk("failed to delete reference to %.*s, "
+ "inode %lu parent %lu\n", name_len, name,
+ dentry->d_inode->i_ino,
+ dentry->d_parent->d_inode->i_ino);
+ }
+ }
err:
btrfs_free_path(path);
if (!ret) {
@@ -445,75 +456,27 @@
int err;
int ret;
struct btrfs_root *root = BTRFS_I(dir)->root;
- struct btrfs_path *path;
- struct btrfs_key key;
struct btrfs_trans_handle *trans;
- struct btrfs_key found_key;
- int found_type;
- struct extent_buffer *leaf;
- char *goodnames = "..";
unsigned long nr;
if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
- path = btrfs_alloc_path();
- BUG_ON(!path);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
-
btrfs_set_trans_block_group(trans, dir);
- key.objectid = inode->i_ino;
- key.offset = (u64)-1;
- key.type = (u8)-1;
- while(1) {
- ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
- if (ret < 0) {
- err = ret;
- goto out;
- }
- BUG_ON(ret == 0);
- if (path->slots[0] == 0) {
- err = -ENOENT;
- goto out;
- }
- path->slots[0]--;
- leaf = path->nodes[0];
- btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
- found_type = btrfs_key_type(&found_key);
- if (found_key.objectid != inode->i_ino) {
- err = -ENOENT;
- goto out;
- }
- if ((found_type != BTRFS_DIR_ITEM_KEY &&
- found_type != BTRFS_DIR_INDEX_KEY) ||
- (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
- !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
- err = -ENOTEMPTY;
- goto out;
- }
- ret = btrfs_del_item(trans, root, path);
- BUG_ON(ret);
-
- if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
- break;
- btrfs_release_path(root, path);
- }
- ret = 0;
- btrfs_release_path(root, path);
/* now the directory is empty */
err = btrfs_unlink_trans(trans, root, dir, dentry);
if (!err) {
inode->i_size = 0;
}
-out:
- btrfs_release_path(root, path);
- btrfs_free_path(path);
+
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root, nr);
+
if (ret && !err)
err = ret;
return err;
@@ -887,21 +850,59 @@
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret = 0;
+ if (namelen == 1 && strcmp(name, ".") == 0) {
+ location->objectid = dir->i_ino;
+ location->type = BTRFS_INODE_ITEM_KEY;
+ location->offset = 0;
+ return 0;
+ }
path = btrfs_alloc_path();
BUG_ON(!path);
+
+ if (namelen == 1 && strcmp(name, "..") == 0) {
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ u32 nritems;
+ int slot;
+
+ key.objectid = dir->i_ino;
+ btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
+ key.offset = 0;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ BUG_ON(ret == 0);
+ ret = 0;
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (slot >= nritems)
+ goto out_err;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid != dir->i_ino ||
+ key.type != BTRFS_INODE_REF_KEY) {
+ goto out_err;
+ }
+ location->objectid = key.offset;
+ location->type = BTRFS_INODE_ITEM_KEY;
+ location->offset = 0;
+ goto out;
+ }
+
di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
namelen, 0);
if (IS_ERR(di))
ret = PTR_ERR(di);
if (!di || IS_ERR(di)) {
- location->objectid = 0;
- goto out;
+ goto out_err;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
out:
- btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
+out_err:
+ location->objectid = 0;
+ goto out;
}
/*
@@ -1053,13 +1054,50 @@
if (root->fs_info->tree_root == root)
key_type = BTRFS_DIR_ITEM_KEY;
+ /* special case for "." */
+ if (filp->f_pos == 0) {
+ over = filldir(dirent, ".", 1,
+ 1, inode->i_ino,
+ DT_DIR);
+ if (over)
+ return 0;
+ filp->f_pos = 1;
+ }
+
mutex_lock(&root->fs_info->fs_mutex);
key.objectid = inode->i_ino;
+ path = btrfs_alloc_path();
+ path->reada = 2;
+
+ /* special case for .., just use the back ref */
+ if (filp->f_pos == 1) {
+ btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
+ key.offset = 0;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ BUG_ON(ret == 0);
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (slot >= nritems) {
+ btrfs_release_path(root, path);
+ goto read_dir_items;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ btrfs_release_path(root, path);
+ if (found_key.objectid != key.objectid ||
+ found_key.type != BTRFS_INODE_REF_KEY)
+ goto read_dir_items;
+ over = filldir(dirent, "..", 2,
+ 2, found_key.offset, DT_DIR);
+ if (over)
+ goto nopos;
+ filp->f_pos = 2;
+ }
+
+read_dir_items:
btrfs_set_key_type(&key, key_type);
key.offset = filp->f_pos;
- path = btrfs_alloc_path();
- path->reada = 2;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
@@ -1255,6 +1293,13 @@
dentry->d_parent->d_inode->i_ino,
&key, btrfs_inode_type(inode));
if (ret == 0) {
+ if (!S_ISLNK(inode->i_mode)) {
+ ret = btrfs_insert_inode_ref(trans, root,
+ dentry->d_name.name,
+ dentry->d_name.len,
+ inode->i_ino,
+ dentry->d_parent->d_inode->i_ino);
+ }
parent_inode = dentry->d_parent->d_inode;
parent_inode->i_size += dentry->d_name.len * 2;
parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
@@ -1430,35 +1475,6 @@
return err;
}
-static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- u64 objectid, u64 dirid)
-{
- int ret;
- char buf[2];
- struct btrfs_key key;
-
- buf[0] = '.';
- buf[1] = '.';
-
- key.objectid = objectid;
- key.offset = 0;
- btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
-
- ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
- &key, BTRFS_FT_DIR);
- if (ret)
- goto error;
-
- key.objectid = dirid;
- ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
- &key, BTRFS_FT_DIR);
- if (ret)
- goto error;
-error:
- return ret;
-}
-
static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct inode *inode;
@@ -1496,11 +1512,7 @@
inode->i_fop = &btrfs_dir_file_operations;
btrfs_set_trans_block_group(trans, inode);
- err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
- if (err)
- goto out_fail;
-
- inode->i_size = 6;
+ inode->i_size = 0;
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_fail;
@@ -1971,6 +1983,12 @@
if (ret)
goto fail;
+ ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
+ name, namelen, objectid,
+ root->fs_info->sb->s_root->d_inode->i_ino);
+ if (ret)
+ goto fail;
+
ret = btrfs_commit_transaction(trans, root);
if (ret)
goto fail_commit;
@@ -1989,12 +2007,10 @@
inode->i_fop = &btrfs_dir_file_operations;
new_root->inode = inode;
- ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
- if (ret)
- goto fail;
-
+ ret = btrfs_insert_inode_ref(trans, new_root, "..", 2, new_dirid,
+ new_dirid);
inode->i_nlink = 1;
- inode->i_size = 6;
+ inode->i_size = 0;
ret = btrfs_update_inode(trans, new_root, inode);
if (ret)
goto fail;
@@ -2068,6 +2084,13 @@
if (ret)
goto fail;
+ ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
+ name, namelen, objectid,
+ root->fs_info->sb->s_root->d_inode->i_ino);
+
+ if (ret)
+ goto fail;
+
ret = btrfs_inc_root_ref(trans, root, objectid);
if (ret)
goto fail;
@@ -2338,7 +2361,6 @@
struct inode *old_inode = old_dentry->d_inode;
struct timespec ctime = CURRENT_TIME;
struct btrfs_path *path;
- struct btrfs_dir_item *di;
int ret;
if (S_ISDIR(old_inode->i_mode) && new_inode &&
@@ -2361,52 +2383,6 @@
new_dir->i_ctime = new_dir->i_mtime = ctime;
old_inode->i_ctime = ctime;
- if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
- struct btrfs_key *location = &BTRFS_I(new_dir)->location;
- struct btrfs_key old_parent_key;
- di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
- "..", 2, -1);
- if (IS_ERR(di)) {
- ret = PTR_ERR(di);
- goto out_fail;
- }
- if (!di) {
- ret = -ENOENT;
- goto out_fail;
- }
- btrfs_dir_item_key_to_cpu(path->nodes[0], di, &old_parent_key);
- ret = btrfs_del_item(trans, root, path);
- if (ret) {
- goto out_fail;
- }
- btrfs_release_path(root, path);
-
- di = btrfs_lookup_dir_index_item(trans, root, path,
- old_inode->i_ino,
- old_parent_key.objectid,
- "..", 2, -1);
- if (IS_ERR(di)) {
- ret = PTR_ERR(di);
- goto out_fail;
- }
- if (!di) {
- ret = -ENOENT;
- goto out_fail;
- }
- ret = btrfs_del_item(trans, root, path);
- if (ret) {
- goto out_fail;
- }
- btrfs_release_path(root, path);
-
- ret = btrfs_insert_dir_item(trans, root, "..", 2,
- old_inode->i_ino, location,
- BTRFS_FT_DIR);
- if (ret)
- goto out_fail;
- }
-
-
ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
if (ret)
goto out_fail;