len = BTRFS_FID_SIZE_NON_CONNECTABLE;
type = FILEID_BTRFS_WITHOUT_PARENT;
- fid->objectid = BTRFS_I(inode)->location.objectid;
+ fid->objectid = inode->i_ino;
fid->root_objectid = BTRFS_I(inode)->root->objectid;
fid->gen = inode->i_generation;
}
static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
- u64 root_objectid, u32 generation)
+ u64 root_objectid, u32 generation,
+ int check_generation)
{
+ struct btrfs_fs_info *fs_info = btrfs_sb(sb)->fs_info;
struct btrfs_root *root;
+ struct dentry *dentry;
struct inode *inode;
struct btrfs_key key;
+ int index;
+ int err = 0;
+
+ if (objectid < BTRFS_FIRST_FREE_OBJECTID)
+ return ERR_PTR(-ESTALE);
key.objectid = root_objectid;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
key.offset = (u64)-1;
- root = btrfs_read_fs_root_no_name(btrfs_sb(sb)->fs_info, &key);
- if (IS_ERR(root))
- return ERR_CAST(root);
+ index = srcu_read_lock(&fs_info->subvol_srcu);
+
+ root = btrfs_read_fs_root_no_name(fs_info, &key);
+ if (IS_ERR(root)) {
+ err = PTR_ERR(root);
+ goto fail;
+ }
+
+ if (btrfs_root_refs(&root->root_item) == 0) {
+ err = -ENOENT;
+ goto fail;
+ }
key.objectid = objectid;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.offset = 0;
inode = btrfs_iget(sb, &key, root);
- if (IS_ERR(inode))
- return (void *)inode;
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto fail;
+ }
+
+ srcu_read_unlock(&fs_info->subvol_srcu, index);
- if (generation != inode->i_generation) {
+ if (check_generation && generation != inode->i_generation) {
iput(inode);
return ERR_PTR(-ESTALE);
}
- return d_obtain_alias(inode);
+ dentry = d_obtain_alias(inode);
+ if (!IS_ERR(dentry))
+ dentry->d_op = &btrfs_dentry_operations;
+ return dentry;
+fail:
+ srcu_read_unlock(&fs_info->subvol_srcu, index);
+ return ERR_PTR(err);
}
static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
objectid = fid->parent_objectid;
generation = fid->parent_gen;
- return btrfs_get_dentry(sb, objectid, root_objectid, generation);
+ return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}
static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
root_objectid = fid->root_objectid;
generation = fid->gen;
- return btrfs_get_dentry(sb, objectid, root_objectid, generation);
+ return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}
static struct dentry *btrfs_get_parent(struct dentry *child)
{
struct inode *dir = child->d_inode;
+ static struct dentry *dentry;
struct btrfs_root *root = BTRFS_I(dir)->root;
- struct btrfs_key key;
struct btrfs_path *path;
struct extent_buffer *leaf;
- int slot;
- u64 objectid;
+ struct btrfs_root_ref *ref;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
int ret;
path = btrfs_alloc_path();
- key.objectid = dir->i_ino;
- btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
- key.offset = (u64)-1;
+ if (dir->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
+ key.objectid = root->root_key.objectid;
+ key.type = BTRFS_ROOT_BACKREF_KEY;
+ key.offset = (u64)-1;
+ root = root->fs_info->tree_root;
+ } else {
+ key.objectid = dir->i_ino;
+ key.type = BTRFS_INODE_REF_KEY;
+ key.offset = (u64)-1;
+ }
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
- if (ret < 0) {
- /* Error */
- btrfs_free_path(path);
- return ERR_PTR(ret);
+ if (ret < 0)
+ goto fail;
+
+ BUG_ON(ret == 0);
+ if (path->slots[0] == 0) {
+ ret = -ENOENT;
+ goto fail;
}
+
+ path->slots[0]--;
leaf = path->nodes[0];
- slot = path->slots[0];
- if (ret) {
- /* btrfs_search_slot() returns the slot where we'd want to
- insert a backref for parent inode #0xFFFFFFFFFFFFFFFF.
- The _real_ backref, telling us what the parent inode
- _actually_ is, will be in the slot _before_ the one
- that btrfs_search_slot() returns. */
- if (!slot) {
- /* Unless there is _no_ key in the tree before... */
- btrfs_free_path(path);
- return ERR_PTR(-EIO);
- }
- slot--;
+
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != key.objectid || found_key.type != key.type) {
+ ret = -ENOENT;
+ goto fail;
}
- btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_root_ref);
+ key.objectid = btrfs_root_ref_dirid(leaf, ref);
+ } else {
+ key.objectid = found_key.offset;
+ }
btrfs_free_path(path);
- if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY)
- return ERR_PTR(-EINVAL);
-
- objectid = key.offset;
-
- /* If we are already at the root of a subvol, return the real root */
- if (objectid == dir->i_ino)
- return dget(dir->i_sb->s_root);
+ if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
+ return btrfs_get_dentry(root->fs_info->sb, key.objectid,
+ found_key.offset, 0, 0);
+ }
- /* Build a new key for the inode item */
- key.objectid = objectid;
- btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
-
- return d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root));
+ dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root));
+ if (!IS_ERR(dentry))
+ dentry->d_op = &btrfs_dentry_operations;
+ return dentry;
+fail:
+ btrfs_free_path(path);
+ return ERR_PTR(ret);
}
const struct export_operations btrfs_export_ops = {
projects / cascardo / linux.git / blobdiff