// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2007 Oracle. All rights reserved. */ #include "ctree.h" #include "fs.h" #include "messages.h" #include "inode-item.h" #include "disk-io.h" #include "transaction.h" #include "print-tree.h" #include "space-info.h" #include "accessors.h" struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf, int slot, const struct fscrypt_str *name) { 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(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, name_ptr, name->len) == 0) return ref; } return NULL; } struct btrfs_inode_extref *btrfs_find_name_in_ext_backref( struct extent_buffer *leaf, int slot, u64 ref_objectid, const struct fscrypt_str *name) { 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(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, name_ptr, name->len) == 0)) return extref; cur_offset += ref_name_len + sizeof(*extref); } return NULL; } /* 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 struct fscrypt_str *name, u64 inode_objectid, u64 ref_objectid, int ins_len, int cow) { int ret; struct btrfs_key key; key.objectid = inode_objectid; key.type = BTRFS_INODE_EXTREF_KEY; key.offset = btrfs_extref_hash(ref_objectid, name->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; return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0], ref_objectid, name); } static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans, struct btrfs_root *root, const struct fscrypt_str *name, 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, 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. */ extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0], ref_objectid, name); if (!extref) { btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL); ret = -EROFS; goto out; } leaf = path->nodes[0]; item_size = btrfs_item_size(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(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 struct fscrypt_str *name, 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; 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; } ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name); if (!ref) { ret = -ENOENT; search_ext_refs = 1; goto out; } leaf = path->nodes[0]; item_size = btrfs_item_size(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(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, 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 struct fscrypt_str *name, 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; key.objectid = inode_objectid; key.type = BTRFS_INODE_EXTREF_KEY; key.offset = btrfs_extref_hash(ref_objectid, name->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->nodes[0], path->slots[0], ref_objectid, name)) goto out; btrfs_extend_item(path, ins_len); ret = 0; } if (ret < 0) goto out; leaf = path->nodes[0]; ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char); ptr += btrfs_item_size(leaf, path->slots[0]) - 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->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 struct fscrypt_str *name, 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->skip_release_on_error = 1; ret = btrfs_insert_empty_item(trans, root, path, &key, ins_len); if (ret == -EEXIST) { u32 old_size; ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name); if (ref) goto out; old_size = btrfs_item_size(path->nodes[0], path->slots[0]); btrfs_extend_item(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)) 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->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, 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; } static inline void btrfs_trace_truncate(struct btrfs_inode *inode, struct extent_buffer *leaf, struct btrfs_file_extent_item *fi, u64 offset, int extent_type, int slot) { if (!inode) return; if (extent_type == BTRFS_FILE_EXTENT_INLINE) trace_btrfs_truncate_show_fi_inline(inode, leaf, fi, slot, offset); else trace_btrfs_truncate_show_fi_regular(inode, leaf, fi, offset); } /* * Remove inode items from a given root. * * @trans: A transaction handle. * @root: The root from which to remove items. * @inode: The inode whose items we want to remove. * @control: The btrfs_truncate_control to control how and what we * are truncating. * * Remove all keys associated with the inode from the given root that have a key * with a type greater than or equals to @min_type. When @min_type has a value of * BTRFS_EXTENT_DATA_KEY, only remove file extent items that have an offset value * greater than or equals to @new_size. If a file extent item that starts before * @new_size and ends after it is found, its length is adjusted. * * Returns: 0 on success, < 0 on error and NEED_TRUNCATE_BLOCK when @min_type is * BTRFS_EXTENT_DATA_KEY and the caller must truncate the last block. */ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_truncate_control *control) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_file_extent_item *fi; struct btrfs_key key; struct btrfs_key found_key; u64 new_size = control->new_size; u64 extent_num_bytes = 0; u64 extent_offset = 0; u64 item_end = 0; u32 found_type = (u8)-1; int del_item; int pending_del_nr = 0; int pending_del_slot = 0; int extent_type = -1; int ret; u64 bytes_deleted = 0; bool be_nice = false; ASSERT(control->inode || !control->clear_extent_range); ASSERT(new_size == 0 || control->min_type == BTRFS_EXTENT_DATA_KEY); control->last_size = new_size; control->sub_bytes = 0; /* * For shareable roots we want to back off from time to time, this turns * out to be subvolume roots, reloc roots, and data reloc roots. */ if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) be_nice = true; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_BACK; key.objectid = control->ino; key.offset = (u64)-1; key.type = (u8)-1; search_again: /* * With a 16K leaf size and 128MiB extents, you can actually queue up a * huge file in a single leaf. Most of the time that bytes_deleted is * > 0, it will be huge by the time we get here */ if (be_nice && bytes_deleted > SZ_32M && btrfs_should_end_transaction(trans)) { ret = -EAGAIN; goto out; } ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) goto out; if (ret > 0) { ret = 0; /* There are no items in the tree for us to truncate, we're done */ if (path->slots[0] == 0) goto out; path->slots[0]--; } while (1) { u64 clear_start = 0, clear_len = 0, extent_start = 0; bool should_throttle = false; fi = NULL; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); found_type = found_key.type; if (found_key.objectid != control->ino) break; if (found_type < control->min_type) break; item_end = found_key.offset; if (found_type == BTRFS_EXTENT_DATA_KEY) { fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_type = btrfs_file_extent_type(leaf, fi); if (extent_type != BTRFS_FILE_EXTENT_INLINE) item_end += btrfs_file_extent_num_bytes(leaf, fi); else if (extent_type == BTRFS_FILE_EXTENT_INLINE) item_end += btrfs_file_extent_ram_bytes(leaf, fi); btrfs_trace_truncate(control->inode, leaf, fi, found_key.offset, extent_type, path->slots[0]); item_end--; } if (found_type > control->min_type) { del_item = 1; } else { if (item_end < new_size) break; if (found_key.offset >= new_size) del_item = 1; else del_item = 0; } /* FIXME, shrink the extent if the ref count is only 1 */ if (found_type != BTRFS_EXTENT_DATA_KEY) goto delete; control->extents_found++; if (extent_type != BTRFS_FILE_EXTENT_INLINE) { u64 num_dec; clear_start = found_key.offset; extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); if (!del_item) { u64 orig_num_bytes = btrfs_file_extent_num_bytes(leaf, fi); extent_num_bytes = ALIGN(new_size - found_key.offset, fs_info->sectorsize); clear_start = ALIGN(new_size, fs_info->sectorsize); btrfs_set_file_extent_num_bytes(leaf, fi, extent_num_bytes); num_dec = (orig_num_bytes - extent_num_bytes); if (extent_start != 0) control->sub_bytes += num_dec; btrfs_mark_buffer_dirty(leaf); } else { extent_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); extent_offset = found_key.offset - btrfs_file_extent_offset(leaf, fi); /* FIXME blocksize != 4096 */ num_dec = btrfs_file_extent_num_bytes(leaf, fi); if (extent_start != 0) control->sub_bytes += num_dec; } clear_len = num_dec; } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { /* * We can't truncate inline items that have had * special encodings */ if (!del_item && btrfs_file_extent_encryption(leaf, fi) == 0 && btrfs_file_extent_other_encoding(leaf, fi) == 0 && btrfs_file_extent_compression(leaf, fi) == 0) { u32 size = (u32)(new_size - found_key.offset); btrfs_set_file_extent_ram_bytes(leaf, fi, size); size = btrfs_file_extent_calc_inline_size(size); btrfs_truncate_item(path, size, 1); } else if (!del_item) { /* * We have to bail so the last_size is set to * just before this extent. */ ret = BTRFS_NEED_TRUNCATE_BLOCK; break; } else { /* * Inline extents are special, we just treat * them as a full sector worth in the file * extent tree just for simplicity sake. */ clear_len = fs_info->sectorsize; } control->sub_bytes += item_end + 1 - new_size; } delete: /* * We only want to clear the file extent range if we're * modifying the actual inode's mapping, which is just the * normal truncate path. */ if (control->clear_extent_range) { ret = btrfs_inode_clear_file_extent_range(control->inode, clear_start, clear_len); if (ret) { btrfs_abort_transaction(trans, ret); break; } } if (del_item) { ASSERT(!pending_del_nr || ((path->slots[0] + 1) == pending_del_slot)); control->last_size = found_key.offset; if (!pending_del_nr) { /* No pending yet, add ourselves */ pending_del_slot = path->slots[0]; pending_del_nr = 1; } else if (pending_del_nr && path->slots[0] + 1 == pending_del_slot) { /* Hop on the pending chunk */ pending_del_nr++; pending_del_slot = path->slots[0]; } } else { control->last_size = new_size; break; } if (del_item && extent_start != 0 && !control->skip_ref_updates) { struct btrfs_ref ref = { 0 }; bytes_deleted += extent_num_bytes; btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, extent_start, extent_num_bytes, 0); btrfs_init_data_ref(&ref, btrfs_header_owner(leaf), control->ino, extent_offset, root->root_key.objectid, false); ret = btrfs_free_extent(trans, &ref); if (ret) { btrfs_abort_transaction(trans, ret); break; } if (be_nice) { if (btrfs_should_throttle_delayed_refs(trans)) should_throttle = true; } } if (found_type == BTRFS_INODE_ITEM_KEY) break; if (path->slots[0] == 0 || path->slots[0] != pending_del_slot || should_throttle) { if (pending_del_nr) { ret = btrfs_del_items(trans, root, path, pending_del_slot, pending_del_nr); if (ret) { btrfs_abort_transaction(trans, ret); break; } pending_del_nr = 0; } btrfs_release_path(path); /* * We can generate a lot of delayed refs, so we need to * throttle every once and a while and make sure we're * adding enough space to keep up with the work we are * generating. Since we hold a transaction here we * can't flush, and we don't want to FLUSH_LIMIT because * we could have generated too many delayed refs to * actually allocate, so just bail if we're short and * let the normal reservation dance happen higher up. */ if (should_throttle) { ret = btrfs_delayed_refs_rsv_refill(fs_info, BTRFS_RESERVE_NO_FLUSH); if (ret) { ret = -EAGAIN; break; } } goto search_again; } else { path->slots[0]--; } } out: if (ret >= 0 && pending_del_nr) { int err; err = btrfs_del_items(trans, root, path, pending_del_slot, pending_del_nr); if (err) { btrfs_abort_transaction(trans, err); ret = err; } } ASSERT(control->last_size >= new_size); if (!ret && control->last_size > new_size) control->last_size = new_size; btrfs_free_path(path); return ret; }