v4.19.13 snapshot.
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
new file mode 100644
index 0000000..a8956a3
--- /dev/null
+++ b/fs/btrfs/inode-item.c
@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ */
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.h"
+
+int btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot,
+ const char *name,
+ int name_len, struct btrfs_inode_ref **ref_ret)
+{
+ struct btrfs_inode_ref *ref;
+ unsigned long ptr;
+ unsigned long name_ptr;
+ u32 item_size;
+ u32 cur_offset = 0;
+ int len;
+
+ item_size = btrfs_item_size_nr(leaf, slot);
+ ptr = btrfs_item_ptr_offset(leaf, slot);
+ 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) {
+ if (ref_ret)
+ *ref_ret = ref;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+int btrfs_find_name_in_ext_backref(struct extent_buffer *leaf, int slot,
+ u64 ref_objectid,
+ const char *name, int name_len,
+ struct btrfs_inode_extref **extref_ret)
+{
+ struct btrfs_inode_extref *extref;
+ unsigned long ptr;
+ unsigned long name_ptr;
+ u32 item_size;
+ u32 cur_offset = 0;
+ int ref_name_len;
+
+ item_size = btrfs_item_size_nr(leaf, slot);
+ ptr = btrfs_item_ptr_offset(leaf, 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(leaf, extref);
+
+ if (ref_name_len == name_len &&
+ btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
+ (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
+ if (extref_ret)
+ *extref_ret = extref;
+ return 1;
+ }
+
+ cur_offset += ref_name_len + sizeof(*extref);
+ }
+ return 0;
+}
+
+/* Returns NULL if no extref found */
+struct btrfs_inode_extref *
+btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ const char *name, int name_len,
+ u64 inode_objectid, u64 ref_objectid, int ins_len,
+ int cow)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_inode_extref *extref;
+
+ key.objectid = inode_objectid;
+ key.type = BTRFS_INODE_EXTREF_KEY;
+ key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+ ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return NULL;
+ if (!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
+ ref_objectid, name, name_len,
+ &extref))
+ return NULL;
+ return extref;
+}
+
+static 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;
+
+ path->leave_spinning = 1;
+
+ 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->nodes[0], path->slots[0],
+ ref_objectid,
+ name, name_len, &extref)) {
+ btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
+ ret = -EROFS;
+ 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(root->fs_info, path, item_size - del_len, 1);
+
+out:
+ btrfs_free_path(path);
+
+ return ret;
+}
+
+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, u64 *index)
+{
+ 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 search_ext_refs = 0;
+ int del_len = name_len + sizeof(*ref);
+
+ key.objectid = inode_objectid;
+ key.offset = ref_objectid;
+ key.type = BTRFS_INODE_REF_KEY;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->leave_spinning = 1;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0) {
+ ret = -ENOENT;
+ search_ext_refs = 1;
+ goto out;
+ } else if (ret < 0) {
+ goto out;
+ }
+ if (!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
+ name, name_len, &ref)) {
+ ret = -ENOENT;
+ search_ext_refs = 1;
+ goto out;
+ }
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+
+ if (index)
+ *index = btrfs_inode_ref_index(leaf, ref);
+
+ 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));
+ btrfs_truncate_item(root->fs_info, path, item_size - sub_item_len, 1);
+out:
+ btrfs_free_path(path);
+
+ if (search_ext_refs) {
+ /*
+ * No refs were found, or we could not find the
+ * name in our ref array. Find and remove the extended
+ * inode ref then.
+ */
+ return btrfs_del_inode_extref(trans, root, name, name_len,
+ inode_objectid, ref_objectid, index);
+ }
+
+ return ret;
+}
+
+/*
+ * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
+ *
+ * The caller must have checked against BTRFS_LINK_MAX already.
+ */
+static 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;
+
+ path->leave_spinning = 1;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ ins_len);
+ if (ret == -EEXIST) {
+ if (btrfs_find_name_in_ext_backref(path->nodes[0],
+ path->slots[0],
+ ref_objectid,
+ name, name_len, NULL))
+ goto out;
+
+ btrfs_extend_item(root->fs_info, 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;
+}
+
+/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
+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, u64 index)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ 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;
+ key.type = BTRFS_INODE_REF_KEY;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->leave_spinning = 1;
+ path->skip_release_on_error = 1;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ ins_len);
+ if (ret == -EEXIST) {
+ u32 old_size;
+
+ if (btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
+ name, name_len, &ref))
+ goto out;
+
+ old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
+ btrfs_extend_item(fs_info, path, ins_len);
+ 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);
+ btrfs_set_inode_ref_index(path->nodes[0], ref, index);
+ ptr = (unsigned long)(ref + 1);
+ ret = 0;
+ } else if (ret < 0) {
+ if (ret == -EOVERFLOW) {
+ if (btrfs_find_name_in_backref(path->nodes[0],
+ path->slots[0],
+ name, name_len, &ref))
+ ret = -EEXIST;
+ else
+ ret = -EMLINK;
+ }
+ 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);
+ 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]);
+
+out:
+ btrfs_free_path(path);
+
+ if (ret == -EMLINK) {
+ struct btrfs_super_block *disk_super = fs_info->super_copy;
+ /* We ran out of space in the ref array. Need to
+ * add an extended ref. */
+ if (btrfs_super_incompat_flags(disk_super)
+ & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
+ ret = btrfs_insert_inode_extref(trans, root, name,
+ name_len,
+ inode_objectid,
+ ref_objectid, index);
+ }
+
+ return ret;
+}
+
+int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid)
+{
+ struct btrfs_key key;
+ int ret;
+ key.objectid = objectid;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(struct btrfs_inode_item));
+ return ret;
+}
+
+int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
+ *root, struct btrfs_path *path,
+ struct btrfs_key *location, int mod)
+{
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+ int ret;
+ int slot;
+ struct extent_buffer *leaf;
+ struct btrfs_key found_key;
+
+ ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
+ if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
+ location->offset == (u64)-1 && path->slots[0] != 0) {
+ slot = path->slots[0] - 1;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (found_key.objectid == location->objectid &&
+ found_key.type == location->type) {
+ path->slots[0]--;
+ return 0;
+ }
+ }
+ return ret;
+}