diff options
Diffstat (limited to 'fs/btrfs/inode-item.c')
| -rw-r--r-- | fs/btrfs/inode-item.c | 751 |
1 files changed, 751 insertions, 0 deletions
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c new file mode 100644 index 0000000000..d3ff97374d --- /dev/null +++ b/fs/btrfs/inode-item.c @@ -0,0 +1,751 @@ +// 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" +#include "extent-tree.h" +#include "file-item.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(trans, 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(trans, 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(trans, 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(trans, 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(trans, 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(trans, 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 refill_delayed_refs_rsv = 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(trans, 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(trans, 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 (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 && btrfs_check_space_for_delayed_refs(fs_info)) + refill_delayed_refs_rsv = true; + } + + if (found_type == BTRFS_INODE_ITEM_KEY) + break; + + if (path->slots[0] == 0 || + path->slots[0] != pending_del_slot || + refill_delayed_refs_rsv) { + 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 (refill_delayed_refs_rsv) { + 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; +} |