// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2008 Oracle. All rights reserved. */ #include #include #include #include #include #include "misc.h" #include "ctree.h" #include "tree-log.h" #include "disk-io.h" #include "locking.h" #include "print-tree.h" #include "backref.h" #include "compression.h" #include "qgroup.h" #include "block-group.h" #include "space-info.h" #include "zoned.h" /* magic values for the inode_only field in btrfs_log_inode: * * LOG_INODE_ALL means to log everything * LOG_INODE_EXISTS means to log just enough to recreate the inode * during log replay */ enum { LOG_INODE_ALL, LOG_INODE_EXISTS, LOG_OTHER_INODE, LOG_OTHER_INODE_ALL, }; /* * directory trouble cases * * 1) on rename or unlink, if the inode being unlinked isn't in the fsync * log, we must force a full commit before doing an fsync of the directory * where the unlink was done. * ---> record transid of last unlink/rename per directory * * mkdir foo/some_dir * normal commit * rename foo/some_dir foo2/some_dir * mkdir foo/some_dir * fsync foo/some_dir/some_file * * The fsync above will unlink the original some_dir without recording * it in its new location (foo2). After a crash, some_dir will be gone * unless the fsync of some_file forces a full commit * * 2) we must log any new names for any file or dir that is in the fsync * log. ---> check inode while renaming/linking. * * 2a) we must log any new names for any file or dir during rename * when the directory they are being removed from was logged. * ---> check inode and old parent dir during rename * * 2a is actually the more important variant. With the extra logging * a crash might unlink the old name without recreating the new one * * 3) after a crash, we must go through any directories with a link count * of zero and redo the rm -rf * * mkdir f1/foo * normal commit * rm -rf f1/foo * fsync(f1) * * The directory f1 was fully removed from the FS, but fsync was never * called on f1, only its parent dir. After a crash the rm -rf must * be replayed. This must be able to recurse down the entire * directory tree. The inode link count fixup code takes care of the * ugly details. */ /* * stages for the tree walking. The first * stage (0) is to only pin down the blocks we find * the second stage (1) is to make sure that all the inodes * we find in the log are created in the subvolume. * * The last stage is to deal with directories and links and extents * and all the other fun semantics */ enum { LOG_WALK_PIN_ONLY, LOG_WALK_REPLAY_INODES, LOG_WALK_REPLAY_DIR_INDEX, LOG_WALK_REPLAY_ALL, }; static int btrfs_log_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, int inode_only, struct btrfs_log_ctx *ctx); static int link_to_fixup_dir(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid); static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_root *log, struct btrfs_path *path, u64 dirid, int del_all); static void wait_log_commit(struct btrfs_root *root, int transid); /* * tree logging is a special write ahead log used to make sure that * fsyncs and O_SYNCs can happen without doing full tree commits. * * Full tree commits are expensive because they require commonly * modified blocks to be recowed, creating many dirty pages in the * extent tree an 4x-6x higher write load than ext3. * * Instead of doing a tree commit on every fsync, we use the * key ranges and transaction ids to find items for a given file or directory * that have changed in this transaction. Those items are copied into * a special tree (one per subvolume root), that tree is written to disk * and then the fsync is considered complete. * * After a crash, items are copied out of the log-tree back into the * subvolume tree. Any file data extents found are recorded in the extent * allocation tree, and the log-tree freed. * * The log tree is read three times, once to pin down all the extents it is * using in ram and once, once to create all the inodes logged in the tree * and once to do all the other items. */ /* * start a sub transaction and setup the log tree * this increments the log tree writer count to make the people * syncing the tree wait for us to finish */ static int start_log_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_log_ctx *ctx) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *tree_root = fs_info->tree_root; const bool zoned = btrfs_is_zoned(fs_info); int ret = 0; bool created = false; /* * First check if the log root tree was already created. If not, create * it before locking the root's log_mutex, just to keep lockdep happy. */ if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) { mutex_lock(&tree_root->log_mutex); if (!fs_info->log_root_tree) { ret = btrfs_init_log_root_tree(trans, fs_info); if (!ret) { set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state); created = true; } } mutex_unlock(&tree_root->log_mutex); if (ret) return ret; } mutex_lock(&root->log_mutex); again: if (root->log_root) { int index = (root->log_transid + 1) % 2; if (btrfs_need_log_full_commit(trans)) { ret = -EAGAIN; goto out; } if (zoned && atomic_read(&root->log_commit[index])) { wait_log_commit(root, root->log_transid - 1); goto again; } if (!root->log_start_pid) { clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); root->log_start_pid = current->pid; } else if (root->log_start_pid != current->pid) { set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); } } else { /* * This means fs_info->log_root_tree was already created * for some other FS trees. Do the full commit not to mix * nodes from multiple log transactions to do sequential * writing. */ if (zoned && !created) { ret = -EAGAIN; goto out; } ret = btrfs_add_log_tree(trans, root); if (ret) goto out; set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state); clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); root->log_start_pid = current->pid; } atomic_inc(&root->log_writers); if (!ctx->logging_new_name) { int index = root->log_transid % 2; list_add_tail(&ctx->list, &root->log_ctxs[index]); ctx->log_transid = root->log_transid; } out: mutex_unlock(&root->log_mutex); return ret; } /* * returns 0 if there was a log transaction running and we were able * to join, or returns -ENOENT if there were not transactions * in progress */ static int join_running_log_trans(struct btrfs_root *root) { const bool zoned = btrfs_is_zoned(root->fs_info); int ret = -ENOENT; if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state)) return ret; mutex_lock(&root->log_mutex); again: if (root->log_root) { int index = (root->log_transid + 1) % 2; ret = 0; if (zoned && atomic_read(&root->log_commit[index])) { wait_log_commit(root, root->log_transid - 1); goto again; } atomic_inc(&root->log_writers); } mutex_unlock(&root->log_mutex); return ret; } /* * This either makes the current running log transaction wait * until you call btrfs_end_log_trans() or it makes any future * log transactions wait until you call btrfs_end_log_trans() */ void btrfs_pin_log_trans(struct btrfs_root *root) { atomic_inc(&root->log_writers); } /* * indicate we're done making changes to the log tree * and wake up anyone waiting to do a sync */ void btrfs_end_log_trans(struct btrfs_root *root) { if (atomic_dec_and_test(&root->log_writers)) { /* atomic_dec_and_test implies a barrier */ cond_wake_up_nomb(&root->log_writer_wait); } } static int btrfs_write_tree_block(struct extent_buffer *buf) { return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start, buf->start + buf->len - 1); } static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf) { filemap_fdatawait_range(buf->pages[0]->mapping, buf->start, buf->start + buf->len - 1); } /* * the walk control struct is used to pass state down the chain when * processing the log tree. The stage field tells us which part * of the log tree processing we are currently doing. The others * are state fields used for that specific part */ struct walk_control { /* should we free the extent on disk when done? This is used * at transaction commit time while freeing a log tree */ int free; /* should we write out the extent buffer? This is used * while flushing the log tree to disk during a sync */ int write; /* should we wait for the extent buffer io to finish? Also used * while flushing the log tree to disk for a sync */ int wait; /* pin only walk, we record which extents on disk belong to the * log trees */ int pin; /* what stage of the replay code we're currently in */ int stage; /* * Ignore any items from the inode currently being processed. Needs * to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in * the LOG_WALK_REPLAY_INODES stage. */ bool ignore_cur_inode; /* the root we are currently replaying */ struct btrfs_root *replay_dest; /* the trans handle for the current replay */ struct btrfs_trans_handle *trans; /* the function that gets used to process blocks we find in the * tree. Note the extent_buffer might not be up to date when it is * passed in, and it must be checked or read if you need the data * inside it */ int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb, struct walk_control *wc, u64 gen, int level); }; /* * process_func used to pin down extents, write them or wait on them */ static int process_one_buffer(struct btrfs_root *log, struct extent_buffer *eb, struct walk_control *wc, u64 gen, int level) { struct btrfs_fs_info *fs_info = log->fs_info; int ret = 0; /* * If this fs is mixed then we need to be able to process the leaves to * pin down any logged extents, so we have to read the block. */ if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) { ret = btrfs_read_buffer(eb, gen, level, NULL); if (ret) return ret; } if (wc->pin) ret = btrfs_pin_extent_for_log_replay(wc->trans, eb->start, eb->len); if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) { if (wc->pin && btrfs_header_level(eb) == 0) ret = btrfs_exclude_logged_extents(eb); if (wc->write) btrfs_write_tree_block(eb); if (wc->wait) btrfs_wait_tree_block_writeback(eb); } return ret; } /* * Item overwrite used by replay and tree logging. eb, slot and key all refer * to the src data we are copying out. * * root is the tree we are copying into, and path is a scratch * path for use in this function (it should be released on entry and * will be released on exit). * * If the key is already in the destination tree the existing item is * overwritten. If the existing item isn't big enough, it is extended. * If it is too large, it is truncated. * * If the key isn't in the destination yet, a new item is inserted. */ static noinline int overwrite_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct extent_buffer *eb, int slot, struct btrfs_key *key) { int ret; u32 item_size; u64 saved_i_size = 0; int save_old_i_size = 0; unsigned long src_ptr; unsigned long dst_ptr; int overwrite_root = 0; bool inode_item = key->type == BTRFS_INODE_ITEM_KEY; if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) overwrite_root = 1; item_size = btrfs_item_size_nr(eb, slot); src_ptr = btrfs_item_ptr_offset(eb, slot); /* look for the key in the destination tree */ ret = btrfs_search_slot(NULL, root, key, path, 0, 0); if (ret < 0) return ret; if (ret == 0) { char *src_copy; char *dst_copy; u32 dst_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); if (dst_size != item_size) goto insert; if (item_size == 0) { btrfs_release_path(path); return 0; } dst_copy = kmalloc(item_size, GFP_NOFS); src_copy = kmalloc(item_size, GFP_NOFS); if (!dst_copy || !src_copy) { btrfs_release_path(path); kfree(dst_copy); kfree(src_copy); return -ENOMEM; } read_extent_buffer(eb, src_copy, src_ptr, item_size); dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); read_extent_buffer(path->nodes[0], dst_copy, dst_ptr, item_size); ret = memcmp(dst_copy, src_copy, item_size); kfree(dst_copy); kfree(src_copy); /* * they have the same contents, just return, this saves * us from cowing blocks in the destination tree and doing * extra writes that may not have been done by a previous * sync */ if (ret == 0) { btrfs_release_path(path); return 0; } /* * We need to load the old nbytes into the inode so when we * replay the extents we've logged we get the right nbytes. */ if (inode_item) { struct btrfs_inode_item *item; u64 nbytes; u32 mode; item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); nbytes = btrfs_inode_nbytes(path->nodes[0], item); item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item); btrfs_set_inode_nbytes(eb, item, nbytes); /* * If this is a directory we need to reset the i_size to * 0 so that we can set it up properly when replaying * the rest of the items in this log. */ mode = btrfs_inode_mode(eb, item); if (S_ISDIR(mode)) btrfs_set_inode_size(eb, item, 0); } } else if (inode_item) { struct btrfs_inode_item *item; u32 mode; /* * New inode, set nbytes to 0 so that the nbytes comes out * properly when we replay the extents. */ item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item); btrfs_set_inode_nbytes(eb, item, 0); /* * If this is a directory we need to reset the i_size to 0 so * that we can set it up properly when replaying the rest of * the items in this log. */ mode = btrfs_inode_mode(eb, item); if (S_ISDIR(mode)) btrfs_set_inode_size(eb, item, 0); } insert: btrfs_release_path(path); /* try to insert the key into the destination tree */ path->skip_release_on_error = 1; ret = btrfs_insert_empty_item(trans, root, path, key, item_size); path->skip_release_on_error = 0; /* make sure any existing item is the correct size */ if (ret == -EEXIST || ret == -EOVERFLOW) { u32 found_size; found_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); if (found_size > item_size) btrfs_truncate_item(path, item_size, 1); else if (found_size < item_size) btrfs_extend_item(path, item_size - found_size); } else if (ret) { return ret; } dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); /* don't overwrite an existing inode if the generation number * was logged as zero. This is done when the tree logging code * is just logging an inode to make sure it exists after recovery. * * Also, don't overwrite i_size on directories during replay. * log replay inserts and removes directory items based on the * state of the tree found in the subvolume, and i_size is modified * as it goes */ if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) { struct btrfs_inode_item *src_item; struct btrfs_inode_item *dst_item; src_item = (struct btrfs_inode_item *)src_ptr; dst_item = (struct btrfs_inode_item *)dst_ptr; if (btrfs_inode_generation(eb, src_item) == 0) { struct extent_buffer *dst_eb = path->nodes[0]; const u64 ino_size = btrfs_inode_size(eb, src_item); /* * For regular files an ino_size == 0 is used only when * logging that an inode exists, as part of a directory * fsync, and the inode wasn't fsynced before. In this * case don't set the size of the inode in the fs/subvol * tree, otherwise we would be throwing valid data away. */ if (S_ISREG(btrfs_inode_mode(eb, src_item)) && S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) && ino_size != 0) btrfs_set_inode_size(dst_eb, dst_item, ino_size); goto no_copy; } if (overwrite_root && S_ISDIR(btrfs_inode_mode(eb, src_item)) && S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) { save_old_i_size = 1; saved_i_size = btrfs_inode_size(path->nodes[0], dst_item); } } copy_extent_buffer(path->nodes[0], eb, dst_ptr, src_ptr, item_size); if (save_old_i_size) { struct btrfs_inode_item *dst_item; dst_item = (struct btrfs_inode_item *)dst_ptr; btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size); } /* make sure the generation is filled in */ if (key->type == BTRFS_INODE_ITEM_KEY) { struct btrfs_inode_item *dst_item; dst_item = (struct btrfs_inode_item *)dst_ptr; if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) { btrfs_set_inode_generation(path->nodes[0], dst_item, trans->transid); } } no_copy: btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(path); return 0; } /* * simple helper to read an inode off the disk from a given root * This can only be called for subvolume roots and not for the log */ static noinline struct inode *read_one_inode(struct btrfs_root *root, u64 objectid) { struct inode *inode; inode = btrfs_iget(root->fs_info->sb, objectid, root); if (IS_ERR(inode)) inode = NULL; return inode; } /* replays a single extent in 'eb' at 'slot' with 'key' into the * subvolume 'root'. path is released on entry and should be released * on exit. * * extents in the log tree have not been allocated out of the extent * tree yet. So, this completes the allocation, taking a reference * as required if the extent already exists or creating a new extent * if it isn't in the extent allocation tree yet. * * The extent is inserted into the file, dropping any existing extents * from the file that overlap the new one. */ static noinline int replay_one_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct extent_buffer *eb, int slot, struct btrfs_key *key) { struct btrfs_drop_extents_args drop_args = { 0 }; struct btrfs_fs_info *fs_info = root->fs_info; int found_type; u64 extent_end; u64 start = key->offset; u64 nbytes = 0; struct btrfs_file_extent_item *item; struct inode *inode = NULL; unsigned long size; int ret = 0; item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); found_type = btrfs_file_extent_type(eb, item); if (found_type == BTRFS_FILE_EXTENT_REG || found_type == BTRFS_FILE_EXTENT_PREALLOC) { nbytes = btrfs_file_extent_num_bytes(eb, item); extent_end = start + nbytes; /* * We don't add to the inodes nbytes if we are prealloc or a * hole. */ if (btrfs_file_extent_disk_bytenr(eb, item) == 0) nbytes = 0; } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { size = btrfs_file_extent_ram_bytes(eb, item); nbytes = btrfs_file_extent_ram_bytes(eb, item); extent_end = ALIGN(start + size, fs_info->sectorsize); } else { ret = 0; goto out; } inode = read_one_inode(root, key->objectid); if (!inode) { ret = -EIO; goto out; } /* * first check to see if we already have this extent in the * file. This must be done before the btrfs_drop_extents run * so we don't try to drop this extent. */ ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(BTRFS_I(inode)), start, 0); if (ret == 0 && (found_type == BTRFS_FILE_EXTENT_REG || found_type == BTRFS_FILE_EXTENT_PREALLOC)) { struct btrfs_file_extent_item cmp1; struct btrfs_file_extent_item cmp2; struct btrfs_file_extent_item *existing; struct extent_buffer *leaf; leaf = path->nodes[0]; existing = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); read_extent_buffer(eb, &cmp1, (unsigned long)item, sizeof(cmp1)); read_extent_buffer(leaf, &cmp2, (unsigned long)existing, sizeof(cmp2)); /* * we already have a pointer to this exact extent, * we don't have to do anything */ if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) { btrfs_release_path(path); goto out; } } btrfs_release_path(path); /* drop any overlapping extents */ drop_args.start = start; drop_args.end = extent_end; drop_args.drop_cache = true; ret = btrfs_drop_extents(trans, root, BTRFS_I(inode), &drop_args); if (ret) goto out; if (found_type == BTRFS_FILE_EXTENT_REG || found_type == BTRFS_FILE_EXTENT_PREALLOC) { u64 offset; unsigned long dest_offset; struct btrfs_key ins; if (btrfs_file_extent_disk_bytenr(eb, item) == 0 && btrfs_fs_incompat(fs_info, NO_HOLES)) goto update_inode; ret = btrfs_insert_empty_item(trans, root, path, key, sizeof(*item)); if (ret) goto out; dest_offset = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); copy_extent_buffer(path->nodes[0], eb, dest_offset, (unsigned long)item, sizeof(*item)); ins.objectid = btrfs_file_extent_disk_bytenr(eb, item); ins.offset = btrfs_file_extent_disk_num_bytes(eb, item); ins.type = BTRFS_EXTENT_ITEM_KEY; offset = key->offset - btrfs_file_extent_offset(eb, item); /* * Manually record dirty extent, as here we did a shallow * file extent item copy and skip normal backref update, * but modifying extent tree all by ourselves. * So need to manually record dirty extent for qgroup, * as the owner of the file extent changed from log tree * (doesn't affect qgroup) to fs/file tree(affects qgroup) */ ret = btrfs_qgroup_trace_extent(trans, btrfs_file_extent_disk_bytenr(eb, item), btrfs_file_extent_disk_num_bytes(eb, item), GFP_NOFS); if (ret < 0) goto out; if (ins.objectid > 0) { struct btrfs_ref ref = { 0 }; u64 csum_start; u64 csum_end; LIST_HEAD(ordered_sums); /* * is this extent already allocated in the extent * allocation tree? If so, just add a reference */ ret = btrfs_lookup_data_extent(fs_info, ins.objectid, ins.offset); if (ret < 0) { goto out; } else if (ret == 0) { btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, ins.objectid, ins.offset, 0); btrfs_init_data_ref(&ref, root->root_key.objectid, key->objectid, offset); ret = btrfs_inc_extent_ref(trans, &ref); if (ret) goto out; } else { /* * insert the extent pointer in the extent * allocation tree */ ret = btrfs_alloc_logged_file_extent(trans, root->root_key.objectid, key->objectid, offset, &ins); if (ret) goto out; } btrfs_release_path(path); if (btrfs_file_extent_compression(eb, item)) { csum_start = ins.objectid; csum_end = csum_start + ins.offset; } else { csum_start = ins.objectid + btrfs_file_extent_offset(eb, item); csum_end = csum_start + btrfs_file_extent_num_bytes(eb, item); } ret = btrfs_lookup_csums_range(root->log_root, csum_start, csum_end - 1, &ordered_sums, 0); if (ret) goto out; /* * Now delete all existing cums in the csum root that * cover our range. We do this because we can have an * extent that is completely referenced by one file * extent item and partially referenced by another * file extent item (like after using the clone or * extent_same ioctls). In this case if we end up doing * the replay of the one that partially references the * extent first, and we do not do the csum deletion * below, we can get 2 csum items in the csum tree that * overlap each other. For example, imagine our log has * the two following file extent items: * * key (257 EXTENT_DATA 409600) * extent data disk byte 12845056 nr 102400 * extent data offset 20480 nr 20480 ram 102400 * * key (257 EXTENT_DATA 819200) * extent data disk byte 12845056 nr 102400 * extent data offset 0 nr 102400 ram 102400 * * Where the second one fully references the 100K extent * that starts at disk byte 12845056, and the log tree * has a single csum item that covers the entire range * of the extent: * * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100 * * After the first file extent item is replayed, the * csum tree gets the following csum item: * * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20 * * Which covers the 20K sub-range starting at offset 20K * of our extent. Now when we replay the second file * extent item, if we do not delete existing csum items * that cover any of its blocks, we end up getting two * csum items in our csum tree that overlap each other: * * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20 * * Which is a problem, because after this anyone trying * to lookup up for the checksum of any block of our * extent starting at an offset of 40K or higher, will * end up looking at the second csum item only, which * does not contain the checksum for any block starting * at offset 40K or higher of our extent. */ while (!list_empty(&ordered_sums)) { struct btrfs_ordered_sum *sums; sums = list_entry(ordered_sums.next, struct btrfs_ordered_sum, list); if (!ret) ret = btrfs_del_csums(trans, fs_info->csum_root, sums->bytenr, sums->len); if (!ret) ret = btrfs_csum_file_blocks(trans, fs_info->csum_root, sums); list_del(&sums->list); kfree(sums); } if (ret) goto out; } else { btrfs_release_path(path); } } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { /* inline extents are easy, we just overwrite them */ ret = overwrite_item(trans, root, path, eb, slot, key); if (ret) goto out; } ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start, extent_end - start); if (ret) goto out; update_inode: btrfs_update_inode_bytes(BTRFS_I(inode), nbytes, drop_args.bytes_found); ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); out: if (inode) iput(inode); return ret; } /* * when cleaning up conflicts between the directory names in the * subvolume, directory names in the log and directory names in the * inode back references, we may have to unlink inodes from directories. * * This is a helper function to do the unlink of a specific directory * item */ static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_inode *dir, struct btrfs_dir_item *di) { struct inode *inode; char *name; int name_len; struct extent_buffer *leaf; struct btrfs_key location; int ret; leaf = path->nodes[0]; btrfs_dir_item_key_to_cpu(leaf, di, &location); name_len = btrfs_dir_name_len(leaf, di); name = kmalloc(name_len, GFP_NOFS); if (!name) return -ENOMEM; read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len); btrfs_release_path(path); inode = read_one_inode(root, location.objectid); if (!inode) { ret = -EIO; goto out; } ret = link_to_fixup_dir(trans, root, path, location.objectid); if (ret) goto out; ret = btrfs_unlink_inode(trans, root, dir, BTRFS_I(inode), name, name_len); if (ret) goto out; else ret = btrfs_run_delayed_items(trans); out: kfree(name); iput(inode); return ret; } /* * See if a given name and sequence number found in an inode back reference are * already in a directory and correctly point to this inode. * * Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it * exists. */ static noinline int inode_in_dir(struct btrfs_root *root, struct btrfs_path *path, u64 dirid, u64 objectid, u64 index, const char *name, int name_len) { struct btrfs_dir_item *di; struct btrfs_key location; int ret = 0; di = btrfs_lookup_dir_index_item(NULL, root, path, dirid, index, name, name_len, 0); if (IS_ERR(di)) { ret = PTR_ERR(di); goto out; } else if (di) { btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); if (location.objectid != objectid) goto out; } else { goto out; } btrfs_release_path(path); di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0); if (IS_ERR(di)) { ret = PTR_ERR(di); goto out; } else if (di) { btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); if (location.objectid == objectid) ret = 1; } out: btrfs_release_path(path); return ret; } /* * helper function to check a log tree for a named back reference in * an inode. This is used to decide if a back reference that is * found in the subvolume conflicts with what we find in the log. * * inode backreferences may have multiple refs in a single item, * during replay we process one reference at a time, and we don't * want to delete valid links to a file from the subvolume if that * link is also in the log. */ static noinline int backref_in_log(struct btrfs_root *log, struct btrfs_key *key, u64 ref_objectid, const char *name, int namelen) { struct btrfs_path *path; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = btrfs_search_slot(NULL, log, key, path, 0, 0); if (ret < 0) { goto out; } else if (ret == 1) { ret = 0; goto out; } if (key->type == BTRFS_INODE_EXTREF_KEY) ret = !!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0], ref_objectid, name, namelen); else ret = !!btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name, namelen); out: btrfs_free_path(path); return ret; } static inline int __add_inode_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_root *log_root, struct btrfs_inode *dir, struct btrfs_inode *inode, u64 inode_objectid, u64 parent_objectid, u64 ref_index, char *name, int namelen, int *search_done) { int ret; char *victim_name; int victim_name_len; struct extent_buffer *leaf; struct btrfs_dir_item *di; struct btrfs_key search_key; struct btrfs_inode_extref *extref; again: /* Search old style refs */ search_key.objectid = inode_objectid; search_key.type = BTRFS_INODE_REF_KEY; search_key.offset = parent_objectid; ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); if (ret == 0) { struct btrfs_inode_ref *victim_ref; unsigned long ptr; unsigned long ptr_end; leaf = path->nodes[0]; /* are we trying to overwrite a back ref for the root directory * if so, just jump out, we're done */ if (search_key.objectid == search_key.offset) return 1; /* check all the names in this back reference to see * if they are in the log. if so, we allow them to stay * otherwise they must be unlinked as a conflict */ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]); while (ptr < ptr_end) { victim_ref = (struct btrfs_inode_ref *)ptr; victim_name_len = btrfs_inode_ref_name_len(leaf, victim_ref); victim_name = kmalloc(victim_name_len, GFP_NOFS); if (!victim_name) return -ENOMEM; read_extent_buffer(leaf, victim_name, (unsigned long)(victim_ref + 1), victim_name_len); ret = backref_in_log(log_root, &search_key, parent_objectid, victim_name, victim_name_len); if (ret < 0) { kfree(victim_name); return ret; } else if (!ret) { inc_nlink(&inode->vfs_inode); btrfs_release_path(path); ret = btrfs_unlink_inode(trans, root, dir, inode, victim_name, victim_name_len); kfree(victim_name); if (ret) return ret; ret = btrfs_run_delayed_items(trans); if (ret) return ret; *search_done = 1; goto again; } kfree(victim_name); ptr = (unsigned long)(victim_ref + 1) + victim_name_len; } /* * NOTE: we have searched root tree and checked the * corresponding ref, it does not need to check again. */ *search_done = 1; } btrfs_release_path(path); /* Same search but for extended refs */ extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen, inode_objectid, parent_objectid, 0, 0); if (!IS_ERR_OR_NULL(extref)) { u32 item_size; u32 cur_offset = 0; unsigned long base; struct inode *victim_parent; leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); base = btrfs_item_ptr_offset(leaf, path->slots[0]); while (cur_offset < item_size) { extref = (struct btrfs_inode_extref *)(base + cur_offset); victim_name_len = btrfs_inode_extref_name_len(leaf, extref); if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid) goto next; victim_name = kmalloc(victim_name_len, GFP_NOFS); if (!victim_name) return -ENOMEM; read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name, victim_name_len); search_key.objectid = inode_objectid; search_key.type = BTRFS_INODE_EXTREF_KEY; search_key.offset = btrfs_extref_hash(parent_objectid, victim_name, victim_name_len); ret = backref_in_log(log_root, &search_key, parent_objectid, victim_name, victim_name_len); if (ret < 0) { return ret; } else if (!ret) { ret = -ENOENT; victim_parent = read_one_inode(root, parent_objectid); if (victim_parent) { inc_nlink(&inode->vfs_inode); btrfs_release_path(path); ret = btrfs_unlink_inode(trans, root, BTRFS_I(victim_parent), inode, victim_name, victim_name_len); if (!ret) ret = btrfs_run_delayed_items( trans); } iput(victim_parent); kfree(victim_name); if (ret) return ret; *search_done = 1; goto again; } kfree(victim_name); next: cur_offset += victim_name_len + sizeof(*extref); } *search_done = 1; } btrfs_release_path(path); /* look for a conflicting sequence number */ di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir), ref_index, name, namelen, 0); if (IS_ERR(di)) { return PTR_ERR(di); } else if (di) { ret = drop_one_dir_item(trans, root, path, dir, di); if (ret) return ret; } btrfs_release_path(path); /* look for a conflicting name */ di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir), name, namelen, 0); if (IS_ERR(di)) { return PTR_ERR(di); } else if (di) { ret = drop_one_dir_item(trans, root, path, dir, di); if (ret) return ret; } btrfs_release_path(path); return 0; } static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr, u32 *namelen, char **name, u64 *index, u64 *parent_objectid) { struct btrfs_inode_extref *extref; extref = (struct btrfs_inode_extref *)ref_ptr; *namelen = btrfs_inode_extref_name_len(eb, extref); *name = kmalloc(*namelen, GFP_NOFS); if (*name == NULL) return -ENOMEM; read_extent_buffer(eb, *name, (unsigned long)&extref->name, *namelen); if (index) *index = btrfs_inode_extref_index(eb, extref); if (parent_objectid) *parent_objectid = btrfs_inode_extref_parent(eb, extref); return 0; } static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr, u32 *namelen, char **name, u64 *index) { struct btrfs_inode_ref *ref; ref = (struct btrfs_inode_ref *)ref_ptr; *namelen = btrfs_inode_ref_name_len(eb, ref); *name = kmalloc(*namelen, GFP_NOFS); if (*name == NULL) return -ENOMEM; read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen); if (index) *index = btrfs_inode_ref_index(eb, ref); return 0; } /* * Take an inode reference item from the log tree and iterate all names from the * inode reference item in the subvolume tree with the same key (if it exists). * For any name that is not in the inode reference item from the log tree, do a * proper unlink of that name (that is, remove its entry from the inode * reference item and both dir index keys). */ static int unlink_old_inode_refs(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_inode *inode, struct extent_buffer *log_eb, int log_slot, struct btrfs_key *key) { int ret; unsigned long ref_ptr; unsigned long ref_end; struct extent_buffer *eb; again: btrfs_release_path(path); ret = btrfs_search_slot(NULL, root, key, path, 0, 0); if (ret > 0) { ret = 0; goto out; } if (ret < 0) goto out; eb = path->nodes[0]; ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]); ref_end = ref_ptr + btrfs_item_size_nr(eb, path->slots[0]); while (ref_ptr < ref_end) { char *name = NULL; int namelen; u64 parent_id; if (key->type == BTRFS_INODE_EXTREF_KEY) { ret = extref_get_fields(eb, ref_ptr, &namelen, &name, NULL, &parent_id); } else { parent_id = key->offset; ret = ref_get_fields(eb, ref_ptr, &namelen, &name, NULL); } if (ret) goto out; if (key->type == BTRFS_INODE_EXTREF_KEY) ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot, parent_id, name, namelen); else ret = !!btrfs_find_name_in_backref(log_eb, log_slot, name, namelen); if (!ret) { struct inode *dir; btrfs_release_path(path); dir = read_one_inode(root, parent_id); if (!dir) { ret = -ENOENT; kfree(name); goto out; } ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), inode, name, namelen); kfree(name); iput(dir); if (ret) goto out; goto again; } kfree(name); ref_ptr += namelen; if (key->type == BTRFS_INODE_EXTREF_KEY) ref_ptr += sizeof(struct btrfs_inode_extref); else ref_ptr += sizeof(struct btrfs_inode_ref); } ret = 0; out: btrfs_release_path(path); return ret; } static int btrfs_inode_ref_exists(struct inode *inode, struct inode *dir, const u8 ref_type, const char *name, const int namelen) { struct btrfs_key key; struct btrfs_path *path; const u64 parent_id = btrfs_ino(BTRFS_I(dir)); int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = btrfs_ino(BTRFS_I(inode)); key.type = ref_type; if (key.type == BTRFS_INODE_REF_KEY) key.offset = parent_id; else key.offset = btrfs_extref_hash(parent_id, name, namelen); ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &key, path, 0, 0); if (ret < 0) goto out; if (ret > 0) { ret = 0; goto out; } if (key.type == BTRFS_INODE_EXTREF_KEY) ret = !!btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0], parent_id, name, namelen); else ret = !!btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name, namelen); out: btrfs_free_path(path); return ret; } static int add_link(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, struct inode *inode, const char *name, int namelen, u64 ref_index) { struct btrfs_dir_item *dir_item; struct btrfs_key key; struct btrfs_path *path; struct inode *other_inode = NULL; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; dir_item = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)), name, namelen, 0); if (!dir_item) { btrfs_release_path(path); goto add_link; } else if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } /* * Our inode's dentry collides with the dentry of another inode which is * in the log but not yet processed since it has a higher inode number. * So delete that other dentry. */ btrfs_dir_item_key_to_cpu(path->nodes[0], dir_item, &key); btrfs_release_path(path); other_inode = read_one_inode(root, key.objectid); if (!other_inode) { ret = -ENOENT; goto out; } ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), BTRFS_I(other_inode), name, namelen); if (ret) goto out; /* * If we dropped the link count to 0, bump it so that later the iput() * on the inode will not free it. We will fixup the link count later. */ if (other_inode->i_nlink == 0) inc_nlink(other_inode); ret = btrfs_run_delayed_items(trans); if (ret) goto out; add_link: ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name, namelen, 0, ref_index); out: iput(other_inode); btrfs_free_path(path); return ret; } /* * replay one inode back reference item found in the log tree. * eb, slot and key refer to the buffer and key found in the log tree. * root is the destination we are replaying into, and path is for temp * use by this function. (it should be released on return). */ static noinline int add_inode_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_root *log, struct btrfs_path *path, struct extent_buffer *eb, int slot, struct btrfs_key *key) { struct inode *dir = NULL; struct inode *inode = NULL; unsigned long ref_ptr; unsigned long ref_end; char *name = NULL; int namelen; int ret; int search_done = 0; int log_ref_ver = 0; u64 parent_objectid; u64 inode_objectid; u64 ref_index = 0; int ref_struct_size; ref_ptr = btrfs_item_ptr_offset(eb, slot); ref_end = ref_ptr + btrfs_item_size_nr(eb, slot); if (key->type == BTRFS_INODE_EXTREF_KEY) { struct btrfs_inode_extref *r; ref_struct_size = sizeof(struct btrfs_inode_extref); log_ref_ver = 1; r = (struct btrfs_inode_extref *)ref_ptr; parent_objectid = btrfs_inode_extref_parent(eb, r); } else { ref_struct_size = sizeof(struct btrfs_inode_ref); parent_objectid = key->offset; } inode_objectid = key->objectid; /* * it is possible that we didn't log all the parent directories * for a given inode. If we don't find the dir, just don't * copy the back ref in. The link count fixup code will take * care of the rest */ dir = read_one_inode(root, parent_objectid); if (!dir) { ret = -ENOENT; goto out; } inode = read_one_inode(root, inode_objectid); if (!inode) { ret = -EIO; goto out; } while (ref_ptr < ref_end) { if (log_ref_ver) { ret = extref_get_fields(eb, ref_ptr, &namelen, &name, &ref_index, &parent_objectid); /* * parent object can change from one array * item to another. */ if (!dir) dir = read_one_inode(root, parent_objectid); if (!dir) { ret = -ENOENT; goto out; } } else { ret = ref_get_fields(eb, ref_ptr, &namelen, &name, &ref_index); } if (ret) goto out; ret = inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)), btrfs_ino(BTRFS_I(inode)), ref_index, name, namelen); if (ret < 0) { goto out; } else if (ret == 0) { /* * look for a conflicting back reference in the * metadata. if we find one we have to unlink that name * of the file before we add our new link. Later on, we * overwrite any existing back reference, and we don't * want to create dangling pointers in the directory. */ if (!search_done) { ret = __add_inode_ref(trans, root, path, log, BTRFS_I(dir), BTRFS_I(inode), inode_objectid, parent_objectid, ref_index, name, namelen, &search_done); if (ret) { if (ret == 1) ret = 0; goto out; } } /* * If a reference item already exists for this inode * with the same parent and name, but different index, * drop it and the corresponding directory index entries * from the parent before adding the new reference item * and dir index entries, otherwise we would fail with * -EEXIST returned from btrfs_add_link() below. */ ret = btrfs_inode_ref_exists(inode, dir, key->type, name, namelen); if (ret > 0) { ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), BTRFS_I(inode), name, namelen); /* * If we dropped the link count to 0, bump it so * that later the iput() on the inode will not * free it. We will fixup the link count later. */ if (!ret && inode->i_nlink == 0) inc_nlink(inode); } if (ret < 0) goto out; /* insert our name */ ret = add_link(trans, root, dir, inode, name, namelen, ref_index); if (ret) goto out; ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); if (ret) goto out; } /* Else, ret == 1, we already have a perfect match, we're done. */ ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen; kfree(name); name = NULL; if (log_ref_ver) { iput(dir); dir = NULL; } } /* * Before we overwrite the inode reference item in the subvolume tree * with the item from the log tree, we must unlink all names from the * parent directory that are in the subvolume's tree inode reference * item, otherwise we end up with an inconsistent subvolume tree where * dir index entries exist for a name but there is no inode reference * item with the same name. */ ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot, key); if (ret) goto out; /* finally write the back reference in the inode */ ret = overwrite_item(trans, root, path, eb, slot, key); out: btrfs_release_path(path); kfree(name); iput(dir); iput(inode); return ret; } static int count_inode_extrefs(struct btrfs_root *root, struct btrfs_inode *inode, struct btrfs_path *path) { int ret = 0; int name_len; unsigned int nlink = 0; u32 item_size; u32 cur_offset = 0; u64 inode_objectid = btrfs_ino(inode); u64 offset = 0; unsigned long ptr; struct btrfs_inode_extref *extref; struct extent_buffer *leaf; while (1) { ret = btrfs_find_one_extref(root, inode_objectid, offset, path, &extref, &offset); if (ret) break; leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); cur_offset = 0; while (cur_offset < item_size) { extref = (struct btrfs_inode_extref *) (ptr + cur_offset); name_len = btrfs_inode_extref_name_len(leaf, extref); nlink++; cur_offset += name_len + sizeof(*extref); } offset++; btrfs_release_path(path); } btrfs_release_path(path); if (ret < 0 && ret != -ENOENT) return ret; return nlink; } static int count_inode_refs(struct btrfs_root *root, struct btrfs_inode *inode, struct btrfs_path *path) { int ret; struct btrfs_key key; unsigned int nlink = 0; unsigned long ptr; unsigned long ptr_end; int name_len; u64 ino = btrfs_ino(inode); key.objectid = ino; key.type = BTRFS_INODE_REF_KEY; key.offset = (u64)-1; while (1) { ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) break; if (ret > 0) { if (path->slots[0] == 0) break; path->slots[0]--; } process_slot: btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid != ino || key.type != BTRFS_INODE_REF_KEY) break; ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); ptr_end = ptr + btrfs_item_size_nr(path->nodes[0], path->slots[0]); while (ptr < ptr_end) { struct btrfs_inode_ref *ref; ref = (struct btrfs_inode_ref *)ptr; name_len = btrfs_inode_ref_name_len(path->nodes[0], ref); ptr = (unsigned long)(ref + 1) + name_len; nlink++; } if (key.offset == 0) break; if (path->slots[0] > 0) { path->slots[0]--; goto process_slot; } key.offset--; btrfs_release_path(path); } btrfs_release_path(path); return nlink; } /* * There are a few corners where the link count of the file can't * be properly maintained during replay. So, instead of adding * lots of complexity to the log code, we just scan the backrefs * for any file that has been through replay. * * The scan will update the link count on the inode to reflect the * number of back refs found. If it goes down to zero, the iput * will free the inode. */ static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode) { struct btrfs_path *path; int ret; u64 nlink = 0; u64 ino = btrfs_ino(BTRFS_I(inode)); path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = count_inode_refs(root, BTRFS_I(inode), path); if (ret < 0) goto out; nlink = ret; ret = count_inode_extrefs(root, BTRFS_I(inode), path); if (ret < 0) goto out; nlink += ret; ret = 0; if (nlink != inode->i_nlink) { set_nlink(inode, nlink); ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); if (ret) goto out; } BTRFS_I(inode)->index_cnt = (u64)-1; if (inode->i_nlink == 0) { if (S_ISDIR(inode->i_mode)) { ret = replay_dir_deletes(trans, root, NULL, path, ino, 1); if (ret) goto out; } ret = btrfs_insert_orphan_item(trans, root, ino); if (ret == -EEXIST) ret = 0; } out: btrfs_free_path(path); return ret; } static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path) { int ret; struct btrfs_key key; struct inode *inode; key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; key.type = BTRFS_ORPHAN_ITEM_KEY; key.offset = (u64)-1; while (1) { ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) break; if (ret == 1) { ret = 0; if (path->slots[0] == 0) break; path->slots[0]--; } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID || key.type != BTRFS_ORPHAN_ITEM_KEY) break; ret = btrfs_del_item(trans, root, path); if (ret) break; btrfs_release_path(path); inode = read_one_inode(root, key.offset); if (!inode) { ret = -EIO; break; } ret = fixup_inode_link_count(trans, root, inode); iput(inode); if (ret) break; /* * fixup on a directory may create new entries, * make sure we always look for the highset possible * offset */ key.offset = (u64)-1; } btrfs_release_path(path); return ret; } /* * record a given inode in the fixup dir so we can check its link * count when replay is done. The link count is incremented here * so the inode won't go away until we check it */ static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid) { struct btrfs_key key; int ret = 0; struct inode *inode; inode = read_one_inode(root, objectid); if (!inode) return -EIO; key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; key.type = BTRFS_ORPHAN_ITEM_KEY; key.offset = objectid; ret = btrfs_insert_empty_item(trans, root, path, &key, 0); btrfs_release_path(path); if (ret == 0) { if (!inode->i_nlink) set_nlink(inode, 1); else inc_nlink(inode); ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); } else if (ret == -EEXIST) { ret = 0; } iput(inode); return ret; } /* * when replaying the log for a directory, we only insert names * for inodes that actually exist. This means an fsync on a directory * does not implicitly fsync all the new files in it */ static noinline int insert_one_name(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 dirid, u64 index, char *name, int name_len, struct btrfs_key *location) { struct inode *inode; struct inode *dir; int ret; inode = read_one_inode(root, location->objectid); if (!inode) return -ENOENT; dir = read_one_inode(root, dirid); if (!dir) { iput(inode); return -EIO; } ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name, name_len, 1, index); /* FIXME, put inode into FIXUP list */ iput(inode); iput(dir); return ret; } /* * take a single entry in a log directory item and replay it into * the subvolume. * * if a conflicting item exists in the subdirectory already, * the inode it points to is unlinked and put into the link count * fix up tree. * * If a name from the log points to a file or directory that does * not exist in the FS, it is skipped. fsyncs on directories * do not force down inodes inside that directory, just changes to the * names or unlinks in a directory. * * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a * non-existing inode) and 1 if the name was replayed. */ static noinline int replay_one_name(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct extent_buffer *eb, struct btrfs_dir_item *di, struct btrfs_key *key) { char *name; int name_len; struct btrfs_dir_item *dst_di; struct btrfs_key found_key; struct btrfs_key log_key; struct inode *dir; u8 log_type; bool exists; int ret; bool update_size = (key->type == BTRFS_DIR_INDEX_KEY); bool name_added = false; dir = read_one_inode(root, key->objectid); if (!dir) return -EIO; name_len = btrfs_dir_name_len(eb, di); name = kmalloc(name_len, GFP_NOFS); if (!name) { ret = -ENOMEM; goto out; } log_type = btrfs_dir_type(eb, di); read_extent_buffer(eb, name, (unsigned long)(di + 1), name_len); btrfs_dir_item_key_to_cpu(eb, di, &log_key); ret = btrfs_lookup_inode(trans, root, path, &log_key, 0); btrfs_release_path(path); if (ret < 0) goto out; exists = (ret == 0); ret = 0; if (key->type == BTRFS_DIR_ITEM_KEY) { dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid, name, name_len, 1); } else if (key->type == BTRFS_DIR_INDEX_KEY) { dst_di = btrfs_lookup_dir_index_item(trans, root, path, key->objectid, key->offset, name, name_len, 1); } else { /* Corruption */ ret = -EINVAL; goto out; } if (IS_ERR(dst_di)) { ret = PTR_ERR(dst_di); goto out; } else if (!dst_di) { /* we need a sequence number to insert, so we only * do inserts for the BTRFS_DIR_INDEX_KEY types */ if (key->type != BTRFS_DIR_INDEX_KEY) goto out; goto insert; } btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key); /* the existing item matches the logged item */ if (found_key.objectid == log_key.objectid && found_key.type == log_key.type && found_key.offset == log_key.offset && btrfs_dir_type(path->nodes[0], dst_di) == log_type) { update_size = false; goto out; } /* * don't drop the conflicting directory entry if the inode * for the new entry doesn't exist */ if (!exists) goto out; ret = drop_one_dir_item(trans, root, path, BTRFS_I(dir), dst_di); if (ret) goto out; if (key->type == BTRFS_DIR_INDEX_KEY) goto insert; out: btrfs_release_path(path); if (!ret && update_size) { btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name_len * 2); ret = btrfs_update_inode(trans, root, BTRFS_I(dir)); } kfree(name); iput(dir); if (!ret && name_added) ret = 1; return ret; insert: /* * Check if the inode reference exists in the log for the given name, * inode and parent inode */ found_key.objectid = log_key.objectid; found_key.type = BTRFS_INODE_REF_KEY; found_key.offset = key->objectid; ret = backref_in_log(root->log_root, &found_key, 0, name, name_len); if (ret < 0) { goto out; } else if (ret) { /* The dentry will be added later. */ ret = 0; update_size = false; goto out; } found_key.objectid = log_key.objectid; found_key.type = BTRFS_INODE_EXTREF_KEY; found_key.offset = key->objectid; ret = backref_in_log(root->log_root, &found_key, key->objectid, name, name_len); if (ret < 0) { goto out; } else if (ret) { /* The dentry will be added later. */ ret = 0; update_size = false; goto out; } btrfs_release_path(path); ret = insert_one_name(trans, root, key->objectid, key->offset, name, name_len, &log_key); if (ret && ret != -ENOENT && ret != -EEXIST) goto out; if (!ret) name_added = true; update_size = false; ret = 0; goto out; } /* * find all the names in a directory item and reconcile them into * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than * one name in a directory item, but the same code gets used for * both directory index types */ static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct extent_buffer *eb, int slot, struct btrfs_key *key) { int ret = 0; u32 item_size = btrfs_item_size_nr(eb, slot); struct btrfs_dir_item *di; int name_len; unsigned long ptr; unsigned long ptr_end; struct btrfs_path *fixup_path = NULL; ptr = btrfs_item_ptr_offset(eb, slot); ptr_end = ptr + item_size; while (ptr < ptr_end) { di = (struct btrfs_dir_item *)ptr; name_len = btrfs_dir_name_len(eb, di); ret = replay_one_name(trans, root, path, eb, di, key); if (ret < 0) break; ptr = (unsigned long)(di + 1); ptr += name_len; /* * If this entry refers to a non-directory (directories can not * have a link count > 1) and it was added in the transaction * that was not committed, make sure we fixup the link count of * the inode it the entry points to. Otherwise something like * the following would result in a directory pointing to an * inode with a wrong link that does not account for this dir * entry: * * mkdir testdir * touch testdir/foo * touch testdir/bar * sync * * ln testdir/bar testdir/bar_link * ln testdir/foo testdir/foo_link * xfs_io -c "fsync" testdir/bar * * * * mount fs, log replay happens * * File foo would remain with a link count of 1 when it has two * entries pointing to it in the directory testdir. This would * make it impossible to ever delete the parent directory has * it would result in stale dentries that can never be deleted. */ if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) { struct btrfs_key di_key; if (!fixup_path) { fixup_path = btrfs_alloc_path(); if (!fixup_path) { ret = -ENOMEM; break; } } btrfs_dir_item_key_to_cpu(eb, di, &di_key); ret = link_to_fixup_dir(trans, root, fixup_path, di_key.objectid); if (ret) break; } ret = 0; } btrfs_free_path(fixup_path); return ret; } /* * directory replay has two parts. There are the standard directory * items in the log copied from the subvolume, and range items * created in the log while the subvolume was logged. * * The range items tell us which parts of the key space the log * is authoritative for. During replay, if a key in the subvolume * directory is in a logged range item, but not actually in the log * that means it was deleted from the directory before the fsync * and should be removed. */ static noinline int find_dir_range(struct btrfs_root *root, struct btrfs_path *path, u64 dirid, int key_type, u64 *start_ret, u64 *end_ret) { struct btrfs_key key; u64 found_end; struct btrfs_dir_log_item *item; int ret; int nritems; if (*start_ret == (u64)-1) return 1; key.objectid = dirid; key.type = key_type; key.offset = *start_ret; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; if (ret > 0) { if (path->slots[0] == 0) goto out; path->slots[0]--; } if (ret != 0) btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.type != key_type || key.objectid != dirid) { ret = 1; goto next; } item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_dir_log_item); found_end = btrfs_dir_log_end(path->nodes[0], item); if (*start_ret >= key.offset && *start_ret <= found_end) { ret = 0; *start_ret = key.offset; *end_ret = found_end; goto out; } ret = 1; next: /* check the next slot in the tree to see if it is a valid item */ nritems = btrfs_header_nritems(path->nodes[0]); path->slots[0]++; if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret) goto out; } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.type != key_type || key.objectid != dirid) { ret = 1; goto out; } item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_dir_log_item); found_end = btrfs_dir_log_end(path->nodes[0], item); *start_ret = key.offset; *end_ret = found_end; ret = 0; out: btrfs_release_path(path); return ret; } /* * this looks for a given directory item in the log. If the directory * item is not in the log, the item is removed and the inode it points * to is unlinked */ static noinline int check_item_in_log(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_root *log, struct btrfs_path *path, struct btrfs_path *log_path, struct inode *dir, struct btrfs_key *dir_key) { int ret; struct extent_buffer *eb; int slot; u32 item_size; struct btrfs_dir_item *di; struct btrfs_dir_item *log_di; int name_len; unsigned long ptr; unsigned long ptr_end; char *name; struct inode *inode; struct btrfs_key location; again: eb = path->nodes[0]; slot = path->slots[0]; item_size = btrfs_item_size_nr(eb, slot); ptr = btrfs_item_ptr_offset(eb, slot); ptr_end = ptr + item_size; while (ptr < ptr_end) { di = (struct btrfs_dir_item *)ptr; name_len = btrfs_dir_name_len(eb, di); name = kmalloc(name_len, GFP_NOFS); if (!name) { ret = -ENOMEM; goto out; } read_extent_buffer(eb, name, (unsigned long)(di + 1), name_len); log_di = NULL; if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) { log_di = btrfs_lookup_dir_item(trans, log, log_path, dir_key->objectid, name, name_len, 0); } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) { log_di = btrfs_lookup_dir_index_item(trans, log, log_path, dir_key->objectid, dir_key->offset, name, name_len, 0); } if (!log_di) { btrfs_dir_item_key_to_cpu(eb, di, &location); btrfs_release_path(path); btrfs_release_path(log_path); inode = read_one_inode(root, location.objectid); if (!inode) { kfree(name); return -EIO; } ret = link_to_fixup_dir(trans, root, path, location.objectid); if (ret) { kfree(name); iput(inode); goto out; } inc_nlink(inode); ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), BTRFS_I(inode), name, name_len); if (!ret) ret = btrfs_run_delayed_items(trans); kfree(name); iput(inode); if (ret) goto out; /* there might still be more names under this key * check and repeat if required */ ret = btrfs_search_slot(NULL, root, dir_key, path, 0, 0); if (ret == 0) goto again; ret = 0; goto out; } else if (IS_ERR(log_di)) { kfree(name); return PTR_ERR(log_di); } btrfs_release_path(log_path); kfree(name); ptr = (unsigned long)(di + 1); ptr += name_len; } ret = 0; out: btrfs_release_path(path); btrfs_release_path(log_path); return ret; } static int replay_xattr_deletes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_root *log, struct btrfs_path *path, const u64 ino) { struct btrfs_key search_key; struct btrfs_path *log_path; int i; int nritems; int ret; log_path = btrfs_alloc_path(); if (!log_path) return -ENOMEM; search_key.objectid = ino; search_key.type = BTRFS_XATTR_ITEM_KEY; search_key.offset = 0; again: ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); if (ret < 0) goto out; process_leaf: nritems = btrfs_header_nritems(path->nodes[0]); for (i = path->slots[0]; i < nritems; i++) { struct btrfs_key key; struct btrfs_dir_item *di; struct btrfs_dir_item *log_di; u32 total_size; u32 cur; btrfs_item_key_to_cpu(path->nodes[0], &key, i); if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) { ret = 0; goto out; } di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item); total_size = btrfs_item_size_nr(path->nodes[0], i); cur = 0; while (cur < total_size) { u16 name_len = btrfs_dir_name_len(path->nodes[0], di); u16 data_len = btrfs_dir_data_len(path->nodes[0], di); u32 this_len = sizeof(*di) + name_len + data_len; char *name; name = kmalloc(name_len, GFP_NOFS); if (!name) { ret = -ENOMEM; goto out; } read_extent_buffer(path->nodes[0], name, (unsigned long)(di + 1), name_len); log_di = btrfs_lookup_xattr(NULL, log, log_path, ino, name, name_len, 0); btrfs_release_path(log_path); if (!log_di) { /* Doesn't exist in log tree, so delete it. */ btrfs_release_path(path); di = btrfs_lookup_xattr(trans, root, path, ino, name, name_len, -1); kfree(name); if (IS_ERR(di)) { ret = PTR_ERR(di); goto out; } ASSERT(di); ret = btrfs_delete_one_dir_name(trans, root, path, di); if (ret) goto out; btrfs_release_path(path); search_key = key; goto again; } kfree(name); if (IS_ERR(log_di)) { ret = PTR_ERR(log_di); goto out; } cur += this_len; di = (struct btrfs_dir_item *)((char *)di + this_len); } } ret = btrfs_next_leaf(root, path); if (ret > 0) ret = 0; else if (ret == 0) goto process_leaf; out: btrfs_free_path(log_path); btrfs_release_path(path); return ret; } /* * deletion replay happens before we copy any new directory items * out of the log or out of backreferences from inodes. It * scans the log to find ranges of keys that log is authoritative for, * and then scans the directory to find items in those ranges that are * not present in the log. * * Anything we don't find in the log is unlinked and removed from the * directory. */ static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_root *log, struct btrfs_path *path, u64 dirid, int del_all) { u64 range_start; u64 range_end; int key_type = BTRFS_DIR_LOG_ITEM_KEY; int ret = 0; struct btrfs_key dir_key; struct btrfs_key found_key; struct btrfs_path *log_path; struct inode *dir; dir_key.objectid = dirid; dir_key.type = BTRFS_DIR_ITEM_KEY; log_path = btrfs_alloc_path(); if (!log_path) return -ENOMEM; dir = read_one_inode(root, dirid); /* it isn't an error if the inode isn't there, that can happen * because we replay the deletes before we copy in the inode item * from the log */ if (!dir) { btrfs_free_path(log_path); return 0; } again: range_start = 0; range_end = 0; while (1) { if (del_all) range_end = (u64)-1; else { ret = find_dir_range(log, path, dirid, key_type, &range_start, &range_end); if (ret != 0) break; } dir_key.offset = range_start; while (1) { int nritems; ret = btrfs_search_slot(NULL, root, &dir_key, path, 0, 0); if (ret < 0) goto out; nritems = btrfs_header_nritems(path->nodes[0]); if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret == 1) break; else if (ret < 0) goto out; } btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); if (found_key.objectid != dirid || found_key.type != dir_key.type) goto next_type; if (found_key.offset > range_end) break; ret = check_item_in_log(trans, root, log, path, log_path, dir, &found_key); if (ret) goto out; if (found_key.offset == (u64)-1) break; dir_key.offset = found_key.offset + 1; } btrfs_release_path(path); if (range_end == (u64)-1) break; range_start = range_end + 1; } next_type: ret = 0; if (key_type == BTRFS_DIR_LOG_ITEM_KEY) { key_type = BTRFS_DIR_LOG_INDEX_KEY; dir_key.type = BTRFS_DIR_INDEX_KEY; btrfs_release_path(path); goto again; } out: btrfs_release_path(path); btrfs_free_path(log_path); iput(dir); return ret; } /* * the process_func used to replay items from the log tree. This * gets called in two different stages. The first stage just looks * for inodes and makes sure they are all copied into the subvolume. * * The second stage copies all the other item types from the log into * the subvolume. The two stage approach is slower, but gets rid of * lots of complexity around inodes referencing other inodes that exist * only in the log (references come from either directory items or inode * back refs). */ static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb, struct walk_control *wc, u64 gen, int level) { int nritems; struct btrfs_path *path; struct btrfs_root *root = wc->replay_dest; struct btrfs_key key; int i; int ret; ret = btrfs_read_buffer(eb, gen, level, NULL); if (ret) return ret; level = btrfs_header_level(eb); if (level != 0) return 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; nritems = btrfs_header_nritems(eb); for (i = 0; i < nritems; i++) { btrfs_item_key_to_cpu(eb, &key, i); /* inode keys are done during the first stage */ if (key.type == BTRFS_INODE_ITEM_KEY && wc->stage == LOG_WALK_REPLAY_INODES) { struct btrfs_inode_item *inode_item; u32 mode; inode_item = btrfs_item_ptr(eb, i, struct btrfs_inode_item); /* * If we have a tmpfile (O_TMPFILE) that got fsync'ed * and never got linked before the fsync, skip it, as * replaying it is pointless since it would be deleted * later. We skip logging tmpfiles, but it's always * possible we are replaying a log created with a kernel * that used to log tmpfiles. */ if (btrfs_inode_nlink(eb, inode_item) == 0) { wc->ignore_cur_inode = true; continue; } else { wc->ignore_cur_inode = false; } ret = replay_xattr_deletes(wc->trans, root, log, path, key.objectid); if (ret) break; mode = btrfs_inode_mode(eb, inode_item); if (S_ISDIR(mode)) { ret = replay_dir_deletes(wc->trans, root, log, path, key.objectid, 0); if (ret) break; } ret = overwrite_item(wc->trans, root, path, eb, i, &key); if (ret) break; /* * Before replaying extents, truncate the inode to its * size. We need to do it now and not after log replay * because before an fsync we can have prealloc extents * added beyond the inode's i_size. If we did it after, * through orphan cleanup for example, we would drop * those prealloc extents just after replaying them. */ if (S_ISREG(mode)) { struct btrfs_drop_extents_args drop_args = { 0 }; struct inode *inode; u64 from; inode = read_one_inode(root, key.objectid); if (!inode) { ret = -EIO; break; } from = ALIGN(i_size_read(inode), root->fs_info->sectorsize); drop_args.start = from; drop_args.end = (u64)-1; drop_args.drop_cache = true; ret = btrfs_drop_extents(wc->trans, root, BTRFS_I(inode), &drop_args); if (!ret) { inode_sub_bytes(inode, drop_args.bytes_found); /* Update the inode's nbytes. */ ret = btrfs_update_inode(wc->trans, root, BTRFS_I(inode)); } iput(inode); if (ret) break; } ret = link_to_fixup_dir(wc->trans, root, path, key.objectid); if (ret) break; } if (wc->ignore_cur_inode) continue; if (key.type == BTRFS_DIR_INDEX_KEY && wc->stage == LOG_WALK_REPLAY_DIR_INDEX) { ret = replay_one_dir_item(wc->trans, root, path, eb, i, &key); if (ret) break; } if (wc->stage < LOG_WALK_REPLAY_ALL) continue; /* these keys are simply copied */ if (key.type == BTRFS_XATTR_ITEM_KEY) { ret = overwrite_item(wc->trans, root, path, eb, i, &key); if (ret) break; } else if (key.type == BTRFS_INODE_REF_KEY || key.type == BTRFS_INODE_EXTREF_KEY) { ret = add_inode_ref(wc->trans, root, log, path, eb, i, &key); if (ret && ret != -ENOENT) break; ret = 0; } else if (key.type == BTRFS_EXTENT_DATA_KEY) { ret = replay_one_extent(wc->trans, root, path, eb, i, &key); if (ret) break; } else if (key.type == BTRFS_DIR_ITEM_KEY) { ret = replay_one_dir_item(wc->trans, root, path, eb, i, &key); if (ret) break; } } btrfs_free_path(path); return ret; } /* * Correctly adjust the reserved bytes occupied by a log tree extent buffer */ static void unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start) { struct btrfs_block_group *cache; cache = btrfs_lookup_block_group(fs_info, start); if (!cache) { btrfs_err(fs_info, "unable to find block group for %llu", start); return; } spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); cache->reserved -= fs_info->nodesize; cache->space_info->bytes_reserved -= fs_info->nodesize; spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); btrfs_put_block_group(cache); } static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int *level, struct walk_control *wc) { struct btrfs_fs_info *fs_info = root->fs_info; u64 bytenr; u64 ptr_gen; struct extent_buffer *next; struct extent_buffer *cur; u32 blocksize; int ret = 0; while (*level > 0) { struct btrfs_key first_key; cur = path->nodes[*level]; WARN_ON(btrfs_header_level(cur) != *level); if (path->slots[*level] >= btrfs_header_nritems(cur)) break; bytenr = btrfs_node_blockptr(cur, path->slots[*level]); ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]); blocksize = fs_info->nodesize; next = btrfs_find_create_tree_block(fs_info, bytenr, btrfs_header_owner(cur), *level - 1); if (IS_ERR(next)) return PTR_ERR(next); if (*level == 1) { ret = wc->process_func(root, next, wc, ptr_gen, *level - 1); if (ret) { free_extent_buffer(next); return ret; } path->slots[*level]++; if (wc->free) { ret = btrfs_read_buffer(next, ptr_gen, *level - 1, &first_key); if (ret) { free_extent_buffer(next); return ret; } if (trans) { btrfs_tree_lock(next); btrfs_clean_tree_block(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); ret = btrfs_pin_reserved_extent(trans, bytenr, blocksize); if (ret) { free_extent_buffer(next); return ret; } btrfs_redirty_list_add( trans->transaction, next); } else { if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) clear_extent_buffer_dirty(next); unaccount_log_buffer(fs_info, bytenr); } } free_extent_buffer(next); continue; } ret = btrfs_read_buffer(next, ptr_gen, *level - 1, &first_key); if (ret) { free_extent_buffer(next); return ret; } if (path->nodes[*level-1]) free_extent_buffer(path->nodes[*level-1]); path->nodes[*level-1] = next; *level = btrfs_header_level(next); path->slots[*level] = 0; cond_resched(); } path->slots[*level] = btrfs_header_nritems(path->nodes[*level]); cond_resched(); return 0; } static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int *level, struct walk_control *wc) { struct btrfs_fs_info *fs_info = root->fs_info; int i; int slot; int ret; for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { slot = path->slots[i]; if (slot + 1 < btrfs_header_nritems(path->nodes[i])) { path->slots[i]++; *level = i; WARN_ON(*level == 0); return 0; } else { ret = wc->process_func(root, path->nodes[*level], wc, btrfs_header_generation(path->nodes[*level]), *level); if (ret) return ret; if (wc->free) { struct extent_buffer *next; next = path->nodes[*level]; if (trans) { btrfs_tree_lock(next); btrfs_clean_tree_block(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); ret = btrfs_pin_reserved_extent(trans, path->nodes[*level]->start, path->nodes[*level]->len); if (ret) return ret; } else { if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) clear_extent_buffer_dirty(next); unaccount_log_buffer(fs_info, path->nodes[*level]->start); } } free_extent_buffer(path->nodes[*level]); path->nodes[*level] = NULL; *level = i + 1; } } return 1; } /* * drop the reference count on the tree rooted at 'snap'. This traverses * the tree freeing any blocks that have a ref count of zero after being * decremented. */ static int walk_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *log, struct walk_control *wc) { struct btrfs_fs_info *fs_info = log->fs_info; int ret = 0; int wret; int level; struct btrfs_path *path; int orig_level; path = btrfs_alloc_path(); if (!path) return -ENOMEM; level = btrfs_header_level(log->node); orig_level = level; path->nodes[level] = log->node; atomic_inc(&log->node->refs); path->slots[level] = 0; while (1) { wret = walk_down_log_tree(trans, log, path, &level, wc); if (wret > 0) break; if (wret < 0) { ret = wret; goto out; } wret = walk_up_log_tree(trans, log, path, &level, wc); if (wret > 0) break; if (wret < 0) { ret = wret; goto out; } } /* was the root node processed? if not, catch it here */ if (path->nodes[orig_level]) { ret = wc->process_func(log, path->nodes[orig_level], wc, btrfs_header_generation(path->nodes[orig_level]), orig_level); if (ret) goto out; if (wc->free) { struct extent_buffer *next; next = path->nodes[orig_level]; if (trans) { btrfs_tree_lock(next); btrfs_clean_tree_block(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); ret = btrfs_pin_reserved_extent(trans, next->start, next->len); if (ret) goto out; } else { if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) clear_extent_buffer_dirty(next); unaccount_log_buffer(fs_info, next->start); } } } out: btrfs_free_path(path); return ret; } /* * helper function to update the item for a given subvolumes log root * in the tree of log roots */ static int update_log_root(struct btrfs_trans_handle *trans, struct btrfs_root *log, struct btrfs_root_item *root_item) { struct btrfs_fs_info *fs_info = log->fs_info; int ret; if (log->log_transid == 1) { /* insert root item on the first sync */ ret = btrfs_insert_root(trans, fs_info->log_root_tree, &log->root_key, root_item); } else { ret = btrfs_update_root(trans, fs_info->log_root_tree, &log->root_key, root_item); } return ret; } static void wait_log_commit(struct btrfs_root *root, int transid) { DEFINE_WAIT(wait); int index = transid % 2; /* * we only allow two pending log transactions at a time, * so we know that if ours is more than 2 older than the * current transaction, we're done */ for (;;) { prepare_to_wait(&root->log_commit_wait[index], &wait, TASK_UNINTERRUPTIBLE); if (!(root->log_transid_committed < transid && atomic_read(&root->log_commit[index]))) break; mutex_unlock(&root->log_mutex); schedule(); mutex_lock(&root->log_mutex); } finish_wait(&root->log_commit_wait[index], &wait); } static void wait_for_writer(struct btrfs_root *root) { DEFINE_WAIT(wait); for (;;) { prepare_to_wait(&root->log_writer_wait, &wait, TASK_UNINTERRUPTIBLE); if (!atomic_read(&root->log_writers)) break; mutex_unlock(&root->log_mutex); schedule(); mutex_lock(&root->log_mutex); } finish_wait(&root->log_writer_wait, &wait); } static inline void btrfs_remove_log_ctx(struct btrfs_root *root, struct btrfs_log_ctx *ctx) { mutex_lock(&root->log_mutex); list_del_init(&ctx->list); mutex_unlock(&root->log_mutex); } /* * Invoked in log mutex context, or be sure there is no other task which * can access the list. */ static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root, int index, int error) { struct btrfs_log_ctx *ctx; struct btrfs_log_ctx *safe; list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) { list_del_init(&ctx->list); ctx->log_ret = error; } } /* * btrfs_sync_log does sends a given tree log down to the disk and * updates the super blocks to record it. When this call is done, * you know that any inodes previously logged are safely on disk only * if it returns 0. * * Any other return value means you need to call btrfs_commit_transaction. * Some of the edge cases for fsyncing directories that have had unlinks * or renames done in the past mean that sometimes the only safe * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN, * that has happened. */ int btrfs_sync_log(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_log_ctx *ctx) { int index1; int index2; int mark; int ret; struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *log = root->log_root; struct btrfs_root *log_root_tree = fs_info->log_root_tree; struct btrfs_root_item new_root_item; int log_transid = 0; struct btrfs_log_ctx root_log_ctx; struct blk_plug plug; u64 log_root_start; u64 log_root_level; mutex_lock(&root->log_mutex); log_transid = ctx->log_transid; if (root->log_transid_committed >= log_transid) { mutex_unlock(&root->log_mutex); return ctx->log_ret; } index1 = log_transid % 2; if (atomic_read(&root->log_commit[index1])) { wait_log_commit(root, log_transid); mutex_unlock(&root->log_mutex); return ctx->log_ret; } ASSERT(log_transid == root->log_transid); atomic_set(&root->log_commit[index1], 1); /* wait for previous tree log sync to complete */ if (atomic_read(&root->log_commit[(index1 + 1) % 2])) wait_log_commit(root, log_transid - 1); while (1) { int batch = atomic_read(&root->log_batch); /* when we're on an ssd, just kick the log commit out */ if (!btrfs_test_opt(fs_info, SSD) && test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) { mutex_unlock(&root->log_mutex); schedule_timeout_uninterruptible(1); mutex_lock(&root->log_mutex); } wait_for_writer(root); if (batch == atomic_read(&root->log_batch)) break; } /* bail out if we need to do a full commit */ if (btrfs_need_log_full_commit(trans)) { ret = -EAGAIN; mutex_unlock(&root->log_mutex); goto out; } if (log_transid % 2 == 0) mark = EXTENT_DIRTY; else mark = EXTENT_NEW; /* we start IO on all the marked extents here, but we don't actually * wait for them until later. */ blk_start_plug(&plug); ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark); /* * -EAGAIN happens when someone, e.g., a concurrent transaction * commit, writes a dirty extent in this tree-log commit. This * concurrent write will create a hole writing out the extents, * and we cannot proceed on a zoned filesystem, requiring * sequential writing. While we can bail out to a full commit * here, but we can continue hoping the concurrent writing fills * the hole. */ if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) ret = 0; if (ret) { blk_finish_plug(&plug); btrfs_abort_transaction(trans, ret); btrfs_set_log_full_commit(trans); mutex_unlock(&root->log_mutex); goto out; } /* * We _must_ update under the root->log_mutex in order to make sure we * have a consistent view of the log root we are trying to commit at * this moment. * * We _must_ copy this into a local copy, because we are not holding the * log_root_tree->log_mutex yet. This is important because when we * commit the log_root_tree we must have a consistent view of the * log_root_tree when we update the super block to point at the * log_root_tree bytenr. If we update the log_root_tree here we'll race * with the commit and possibly point at the new block which we may not * have written out. */ btrfs_set_root_node(&log->root_item, log->node); memcpy(&new_root_item, &log->root_item, sizeof(new_root_item)); root->log_transid++; log->log_transid = root->log_transid; root->log_start_pid = 0; /* * IO has been started, blocks of the log tree have WRITTEN flag set * in their headers. new modifications of the log will be written to * new positions. so it's safe to allow log writers to go in. */ mutex_unlock(&root->log_mutex); if (btrfs_is_zoned(fs_info)) { mutex_lock(&fs_info->tree_root->log_mutex); if (!log_root_tree->node) { ret = btrfs_alloc_log_tree_node(trans, log_root_tree); if (ret) { mutex_unlock(&fs_info->tree_root->log_mutex); goto out; } } mutex_unlock(&fs_info->tree_root->log_mutex); } btrfs_init_log_ctx(&root_log_ctx, NULL); mutex_lock(&log_root_tree->log_mutex); index2 = log_root_tree->log_transid % 2; list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]); root_log_ctx.log_transid = log_root_tree->log_transid; /* * Now we are safe to update the log_root_tree because we're under the * log_mutex, and we're a current writer so we're holding the commit * open until we drop the log_mutex. */ ret = update_log_root(trans, log, &new_root_item); if (ret) { if (!list_empty(&root_log_ctx.list)) list_del_init(&root_log_ctx.list); blk_finish_plug(&plug); btrfs_set_log_full_commit(trans); if (ret != -ENOSPC) { btrfs_abort_transaction(trans, ret); mutex_unlock(&log_root_tree->log_mutex); goto out; } btrfs_wait_tree_log_extents(log, mark); mutex_unlock(&log_root_tree->log_mutex); ret = -EAGAIN; goto out; } if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) { blk_finish_plug(&plug); list_del_init(&root_log_ctx.list); mutex_unlock(&log_root_tree->log_mutex); ret = root_log_ctx.log_ret; goto out; } index2 = root_log_ctx.log_transid % 2; if (atomic_read(&log_root_tree->log_commit[index2])) { blk_finish_plug(&plug); ret = btrfs_wait_tree_log_extents(log, mark); wait_log_commit(log_root_tree, root_log_ctx.log_transid); mutex_unlock(&log_root_tree->log_mutex); if (!ret) ret = root_log_ctx.log_ret; goto out; } ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid); atomic_set(&log_root_tree->log_commit[index2], 1); if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) { wait_log_commit(log_root_tree, root_log_ctx.log_transid - 1); } /* * now that we've moved on to the tree of log tree roots, * check the full commit flag again */ if (btrfs_need_log_full_commit(trans)) { blk_finish_plug(&plug); btrfs_wait_tree_log_extents(log, mark); mutex_unlock(&log_root_tree->log_mutex); ret = -EAGAIN; goto out_wake_log_root; } ret = btrfs_write_marked_extents(fs_info, &log_root_tree->dirty_log_pages, EXTENT_DIRTY | EXTENT_NEW); blk_finish_plug(&plug); /* * As described above, -EAGAIN indicates a hole in the extents. We * cannot wait for these write outs since the waiting cause a * deadlock. Bail out to the full commit instead. */ if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) { btrfs_set_log_full_commit(trans); btrfs_wait_tree_log_extents(log, mark); mutex_unlock(&log_root_tree->log_mutex); goto out_wake_log_root; } else if (ret) { btrfs_set_log_full_commit(trans); btrfs_abort_transaction(trans, ret); mutex_unlock(&log_root_tree->log_mutex); goto out_wake_log_root; } ret = btrfs_wait_tree_log_extents(log, mark); if (!ret) ret = btrfs_wait_tree_log_extents(log_root_tree, EXTENT_NEW | EXTENT_DIRTY); if (ret) { btrfs_set_log_full_commit(trans); mutex_unlock(&log_root_tree->log_mutex); goto out_wake_log_root; } log_root_start = log_root_tree->node->start; log_root_level = btrfs_header_level(log_root_tree->node); log_root_tree->log_transid++; mutex_unlock(&log_root_tree->log_mutex); /* * Here we are guaranteed that nobody is going to write the superblock * for the current transaction before us and that neither we do write * our superblock before the previous transaction finishes its commit * and writes its superblock, because: * * 1) We are holding a handle on the current transaction, so no body * can commit it until we release the handle; * * 2) Before writing our superblock we acquire the tree_log_mutex, so * if the previous transaction is still committing, and hasn't yet * written its superblock, we wait for it to do it, because a * transaction commit acquires the tree_log_mutex when the commit * begins and releases it only after writing its superblock. */ mutex_lock(&fs_info->tree_log_mutex); /* * The previous transaction writeout phase could have failed, and thus * marked the fs in an error state. We must not commit here, as we * could have updated our generation in the super_for_commit and * writing the super here would result in transid mismatches. If there * is an error here just bail. */ if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { ret = -EIO; btrfs_set_log_full_commit(trans); btrfs_abort_transaction(trans, ret); mutex_unlock(&fs_info->tree_log_mutex); goto out_wake_log_root; } btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start); btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level); ret = write_all_supers(fs_info, 1); mutex_unlock(&fs_info->tree_log_mutex); if (ret) { btrfs_set_log_full_commit(trans); btrfs_abort_transaction(trans, ret); goto out_wake_log_root; } /* * We know there can only be one task here, since we have not yet set * root->log_commit[index1] to 0 and any task attempting to sync the * log must wait for the previous log transaction to commit if it's * still in progress or wait for the current log transaction commit if * someone else already started it. We use <= and not < because the * first log transaction has an ID of 0. */ ASSERT(root->last_log_commit <= log_transid); root->last_log_commit = log_transid; out_wake_log_root: mutex_lock(&log_root_tree->log_mutex); btrfs_remove_all_log_ctxs(log_root_tree, index2, ret); log_root_tree->log_transid_committed++; atomic_set(&log_root_tree->log_commit[index2], 0); mutex_unlock(&log_root_tree->log_mutex); /* * The barrier before waitqueue_active (in cond_wake_up) is needed so * all the updates above are seen by the woken threads. It might not be * necessary, but proving that seems to be hard. */ cond_wake_up(&log_root_tree->log_commit_wait[index2]); out: mutex_lock(&root->log_mutex); btrfs_remove_all_log_ctxs(root, index1, ret); root->log_transid_committed++; atomic_set(&root->log_commit[index1], 0); mutex_unlock(&root->log_mutex); /* * The barrier before waitqueue_active (in cond_wake_up) is needed so * all the updates above are seen by the woken threads. It might not be * necessary, but proving that seems to be hard. */ cond_wake_up(&root->log_commit_wait[index1]); return ret; } static void free_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *log) { int ret; struct walk_control wc = { .free = 1, .process_func = process_one_buffer }; if (log->node) { ret = walk_log_tree(trans, log, &wc); if (ret) { if (trans) btrfs_abort_transaction(trans, ret); else btrfs_handle_fs_error(log->fs_info, ret, NULL); } } clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1, EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT); extent_io_tree_release(&log->log_csum_range); if (trans && log->node) btrfs_redirty_list_add(trans->transaction, log->node); btrfs_put_root(log); } /* * free all the extents used by the tree log. This should be called * at commit time of the full transaction */ int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) { if (root->log_root) { free_log_tree(trans, root->log_root); root->log_root = NULL; clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state); } return 0; } int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info) { if (fs_info->log_root_tree) { free_log_tree(trans, fs_info->log_root_tree); fs_info->log_root_tree = NULL; clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state); } return 0; } /* * Check if an inode was logged in the current transaction. This may often * return some false positives, because logged_trans is an in memory only field, * not persisted anywhere. This is meant to be used in contexts where a false * positive has no functional consequences. */ static bool inode_logged(struct btrfs_trans_handle *trans, struct btrfs_inode *inode) { if (inode->logged_trans == trans->transid) return true; if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state)) return false; /* * The inode's logged_trans is always 0 when we load it (because it is * not persisted in the inode item or elsewhere). So if it is 0, the * inode was last modified in the current transaction then the inode may * have been logged before in the current transaction, then evicted and * loaded again in the current transaction - or may have never been logged * in the current transaction, but since we can not be sure, we have to * assume it was, otherwise our callers can leave an inconsistent log. */ if (inode->logged_trans == 0 && inode->last_trans == trans->transid && !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags)) return true; return false; } /* * If both a file and directory are logged, and unlinks or renames are * mixed in, we have a few interesting corners: * * create file X in dir Y * link file X to X.link in dir Y * fsync file X * unlink file X but leave X.link * fsync dir Y * * After a crash we would expect only X.link to exist. But file X * didn't get fsync'd again so the log has back refs for X and X.link. * * We solve this by removing directory entries and inode backrefs from the * log when a file that was logged in the current transaction is * unlinked. Any later fsync will include the updated log entries, and * we'll be able to reconstruct the proper directory items from backrefs. * * This optimizations allows us to avoid relogging the entire inode * or the entire directory. */ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, int name_len, struct btrfs_inode *dir, u64 index) { struct btrfs_root *log; struct btrfs_dir_item *di; struct btrfs_path *path; int ret; int err = 0; u64 dir_ino = btrfs_ino(dir); if (!inode_logged(trans, dir)) return 0; ret = join_running_log_trans(root); if (ret) return 0; mutex_lock(&dir->log_mutex); log = root->log_root; path = btrfs_alloc_path(); if (!path) { err = -ENOMEM; goto out_unlock; } di = btrfs_lookup_dir_item(trans, log, path, dir_ino, name, name_len, -1); if (IS_ERR(di)) { err = PTR_ERR(di); goto fail; } if (di) { ret = btrfs_delete_one_dir_name(trans, log, path, di); if (ret) { err = ret; goto fail; } } btrfs_release_path(path); di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino, index, name, name_len, -1); if (IS_ERR(di)) { err = PTR_ERR(di); goto fail; } if (di) { ret = btrfs_delete_one_dir_name(trans, log, path, di); if (ret) { err = ret; goto fail; } } /* * We do not need to update the size field of the directory's inode item * because on log replay we update the field to reflect all existing * entries in the directory (see overwrite_item()). */ fail: btrfs_free_path(path); out_unlock: mutex_unlock(&dir->log_mutex); if (err == -ENOSPC) { btrfs_set_log_full_commit(trans); err = 0; } else if (err < 0) { btrfs_abort_transaction(trans, err); } btrfs_end_log_trans(root); return err; } /* see comments for btrfs_del_dir_entries_in_log */ int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, int name_len, struct btrfs_inode *inode, u64 dirid) { struct btrfs_root *log; u64 index; int ret; if (!inode_logged(trans, inode)) return 0; ret = join_running_log_trans(root); if (ret) return 0; log = root->log_root; mutex_lock(&inode->log_mutex); ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode), dirid, &index); mutex_unlock(&inode->log_mutex); if (ret == -ENOSPC) { btrfs_set_log_full_commit(trans); ret = 0; } else if (ret < 0 && ret != -ENOENT) btrfs_abort_transaction(trans, ret); btrfs_end_log_trans(root); return ret; } /* * creates a range item in the log for 'dirid'. first_offset and * last_offset tell us which parts of the key space the log should * be considered authoritative for. */ static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans, struct btrfs_root *log, struct btrfs_path *path, int key_type, u64 dirid, u64 first_offset, u64 last_offset) { int ret; struct btrfs_key key; struct btrfs_dir_log_item *item; key.objectid = dirid; key.offset = first_offset; if (key_type == BTRFS_DIR_ITEM_KEY) key.type = BTRFS_DIR_LOG_ITEM_KEY; else key.type = BTRFS_DIR_LOG_INDEX_KEY; ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item)); if (ret) return ret; item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_dir_log_item); btrfs_set_dir_log_end(path->nodes[0], item, last_offset); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(path); return 0; } /* * log all the items included in the current transaction for a given * directory. This also creates the range items in the log tree required * to replay anything deleted before the fsync */ static noinline int log_dir_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, struct btrfs_path *path, struct btrfs_path *dst_path, int key_type, struct btrfs_log_ctx *ctx, u64 min_offset, u64 *last_offset_ret) { struct btrfs_key min_key; struct btrfs_root *log = root->log_root; struct extent_buffer *src; int err = 0; int ret; int i; int nritems; u64 first_offset = min_offset; u64 last_offset = (u64)-1; u64 ino = btrfs_ino(inode); log = root->log_root; min_key.objectid = ino; min_key.type = key_type; min_key.offset = min_offset; ret = btrfs_search_forward(root, &min_key, path, trans->transid); /* * we didn't find anything from this transaction, see if there * is anything at all */ if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) { min_key.objectid = ino; min_key.type = key_type; min_key.offset = (u64)-1; btrfs_release_path(path); ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); if (ret < 0) { btrfs_release_path(path); return ret; } ret = btrfs_previous_item(root, path, ino, key_type); /* if ret == 0 there are items for this type, * create a range to tell us the last key of this type. * otherwise, there are no items in this directory after * *min_offset, and we create a range to indicate that. */ if (ret == 0) { struct btrfs_key tmp; btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]); if (key_type == tmp.type) first_offset = max(min_offset, tmp.offset) + 1; } goto done; } /* go backward to find any previous key */ ret = btrfs_previous_item(root, path, ino, key_type); if (ret == 0) { struct btrfs_key tmp; btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]); if (key_type == tmp.type) { first_offset = tmp.offset; ret = overwrite_item(trans, log, dst_path, path->nodes[0], path->slots[0], &tmp); if (ret) { err = ret; goto done; } } } btrfs_release_path(path); /* * Find the first key from this transaction again. See the note for * log_new_dir_dentries, if we're logging a directory recursively we * won't be holding its i_mutex, which means we can modify the directory * while we're logging it. If we remove an entry between our first * search and this search we'll not find the key again and can just * bail. */ search: ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); if (ret != 0) goto done; /* * we have a block from this transaction, log every item in it * from our directory */ while (1) { struct btrfs_key tmp; src = path->nodes[0]; nritems = btrfs_header_nritems(src); for (i = path->slots[0]; i < nritems; i++) { struct btrfs_dir_item *di; btrfs_item_key_to_cpu(src, &min_key, i); if (min_key.objectid != ino || min_key.type != key_type) goto done; if (need_resched()) { btrfs_release_path(path); cond_resched(); goto search; } ret = overwrite_item(trans, log, dst_path, src, i, &min_key); if (ret) { err = ret; goto done; } /* * We must make sure that when we log a directory entry, * the corresponding inode, after log replay, has a * matching link count. For example: * * touch foo * mkdir mydir * sync * ln foo mydir/bar * xfs_io -c "fsync" mydir * * * * Would result in a fsync log that when replayed, our * file inode would have a link count of 1, but we get * two directory entries pointing to the same inode. * After removing one of the names, it would not be * possible to remove the other name, which resulted * always in stale file handle errors, and would not * be possible to rmdir the parent directory, since * its i_size could never decrement to the value * BTRFS_EMPTY_DIR_SIZE, resulting in -ENOTEMPTY errors. */ di = btrfs_item_ptr(src, i, struct btrfs_dir_item); btrfs_dir_item_key_to_cpu(src, di, &tmp); if ((btrfs_dir_transid(src, di) == trans->transid || btrfs_dir_type(src, di) == BTRFS_FT_DIR) && tmp.type != BTRFS_ROOT_ITEM_KEY) ctx->log_new_dentries = true; } path->slots[0] = nritems; /* * look ahead to the next item and see if it is also * from this directory and from this transaction */ ret = btrfs_next_leaf(root, path); if (ret) { if (ret == 1) last_offset = (u64)-1; else err = ret; goto done; } btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]); if (tmp.objectid != ino || tmp.type != key_type) { last_offset = (u64)-1; goto done; } if (btrfs_header_generation(path->nodes[0]) != trans->transid) { ret = overwrite_item(trans, log, dst_path, path->nodes[0], path->slots[0], &tmp); if (ret) err = ret; else last_offset = tmp.offset; goto done; } } done: btrfs_release_path(path); btrfs_release_path(dst_path); if (err == 0) { *last_offset_ret = last_offset; /* * insert the log range keys to indicate where the log * is valid */ ret = insert_dir_log_key(trans, log, path, key_type, ino, first_offset, last_offset); if (ret) err = ret; } return err; } /* * logging directories is very similar to logging inodes, We find all the items * from the current transaction and write them to the log. * * The recovery code scans the directory in the subvolume, and if it finds a * key in the range logged that is not present in the log tree, then it means * that dir entry was unlinked during the transaction. * * In order for that scan to work, we must include one key smaller than * the smallest logged by this transaction and one key larger than the largest * key logged by this transaction. */ static noinline int log_directory_changes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, struct btrfs_path *path, struct btrfs_path *dst_path, struct btrfs_log_ctx *ctx) { u64 min_key; u64 max_key; int ret; int key_type = BTRFS_DIR_ITEM_KEY; again: min_key = 0; max_key = 0; while (1) { ret = log_dir_items(trans, root, inode, path, dst_path, key_type, ctx, min_key, &max_key); if (ret) return ret; if (max_key == (u64)-1) break; min_key = max_key + 1; } if (key_type == BTRFS_DIR_ITEM_KEY) { key_type = BTRFS_DIR_INDEX_KEY; goto again; } return 0; } /* * a helper function to drop items from the log before we relog an * inode. max_key_type indicates the highest item type to remove. * This cannot be run for file data extents because it does not * free the extents they point to. */ static int drop_inode_items(struct btrfs_trans_handle *trans, struct btrfs_root *log, struct btrfs_path *path, struct btrfs_inode *inode, int max_key_type) { int ret; struct btrfs_key key; struct btrfs_key found_key; int start_slot; if (!inode_logged(trans, inode)) return 0; key.objectid = btrfs_ino(inode); key.type = max_key_type; key.offset = (u64)-1; while (1) { ret = btrfs_search_slot(trans, log, &key, path, -1, 1); BUG_ON(ret == 0); /* Logic error */ if (ret < 0) break; if (path->slots[0] == 0) break; path->slots[0]--; btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); if (found_key.objectid != key.objectid) break; found_key.offset = 0; found_key.type = 0; ret = btrfs_bin_search(path->nodes[0], &found_key, &start_slot); if (ret < 0) break; ret = btrfs_del_items(trans, log, path, start_slot, path->slots[0] - start_slot + 1); /* * If start slot isn't 0 then we don't need to re-search, we've * found the last guy with the objectid in this tree. */ if (ret || start_slot != 0) break; btrfs_release_path(path); } btrfs_release_path(path); if (ret > 0) ret = 0; return ret; } static int truncate_inode_items(struct btrfs_trans_handle *trans, struct btrfs_root *log_root, struct btrfs_inode *inode, u64 new_size, u32 min_type) { int ret; do { ret = btrfs_truncate_inode_items(trans, log_root, inode, new_size, min_type, NULL); } while (ret == -EAGAIN); return ret; } static void fill_inode_item(struct btrfs_trans_handle *trans, struct extent_buffer *leaf, struct btrfs_inode_item *item, struct inode *inode, int log_inode_only, u64 logged_isize) { struct btrfs_map_token token; u64 flags; btrfs_init_map_token(&token, leaf); if (log_inode_only) { /* set the generation to zero so the recover code * can tell the difference between an logging * just to say 'this inode exists' and a logging * to say 'update this inode with these values' */ btrfs_set_token_inode_generation(&token, item, 0); btrfs_set_token_inode_size(&token, item, logged_isize); } else { btrfs_set_token_inode_generation(&token, item, BTRFS_I(inode)->generation); btrfs_set_token_inode_size(&token, item, inode->i_size); } btrfs_set_token_inode_uid(&token, item, i_uid_read(inode)); btrfs_set_token_inode_gid(&token, item, i_gid_read(inode)); btrfs_set_token_inode_mode(&token, item, inode->i_mode); btrfs_set_token_inode_nlink(&token, item, inode->i_nlink); btrfs_set_token_timespec_sec(&token, &item->atime, inode->i_atime.tv_sec); btrfs_set_token_timespec_nsec(&token, &item->atime, inode->i_atime.tv_nsec); btrfs_set_token_timespec_sec(&token, &item->mtime, inode->i_mtime.tv_sec); btrfs_set_token_timespec_nsec(&token, &item->mtime, inode->i_mtime.tv_nsec); btrfs_set_token_timespec_sec(&token, &item->ctime, inode->i_ctime.tv_sec); btrfs_set_token_timespec_nsec(&token, &item->ctime, inode->i_ctime.tv_nsec); /* * We do not need to set the nbytes field, in fact during a fast fsync * its value may not even be correct, since a fast fsync does not wait * for ordered extent completion, which is where we update nbytes, it * only waits for writeback to complete. During log replay as we find * file extent items and replay them, we adjust the nbytes field of the * inode item in subvolume tree as needed (see overwrite_item()). */ btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode)); btrfs_set_token_inode_transid(&token, item, trans->transid); btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags, BTRFS_I(inode)->ro_flags); btrfs_set_token_inode_flags(&token, item, flags); btrfs_set_token_inode_block_group(&token, item, 0); } static int log_inode_item(struct btrfs_trans_handle *trans, struct btrfs_root *log, struct btrfs_path *path, struct btrfs_inode *inode, bool inode_item_dropped) { struct btrfs_inode_item *inode_item; int ret; /* * If we are doing a fast fsync and the inode was logged before in the * current transaction, then we know the inode was previously logged and * it exists in the log tree. For performance reasons, in this case use * btrfs_search_slot() directly with ins_len set to 0 so that we never * attempt a write lock on the leaf's parent, which adds unnecessary lock * contention in case there are concurrent fsyncs for other inodes of the * same subvolume. Using btrfs_insert_empty_item() when the inode item * already exists can also result in unnecessarily splitting a leaf. */ if (!inode_item_dropped && inode->logged_trans == trans->transid) { ret = btrfs_search_slot(trans, log, &inode->location, path, 0, 1); ASSERT(ret <= 0); if (ret > 0) ret = -ENOENT; } else { /* * This means it is the first fsync in the current transaction, * so the inode item is not in the log and we need to insert it. * We can never get -EEXIST because we are only called for a fast * fsync and in case an inode eviction happens after the inode was * logged before in the current transaction, when we load again * the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime * flags and set ->logged_trans to 0. */ ret = btrfs_insert_empty_item(trans, log, path, &inode->location, sizeof(*inode_item)); ASSERT(ret != -EEXIST); } if (ret) return ret; inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode, 0, 0); btrfs_release_path(path); return 0; } static int log_csums(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_root *log_root, struct btrfs_ordered_sum *sums) { const u64 lock_end = sums->bytenr + sums->len - 1; struct extent_state *cached_state = NULL; int ret; /* * If this inode was not used for reflink operations in the current * transaction with new extents, then do the fast path, no need to * worry about logging checksum items with overlapping ranges. */ if (inode->last_reflink_trans < trans->transid) return btrfs_csum_file_blocks(trans, log_root, sums); /* * Serialize logging for checksums. This is to avoid racing with the * same checksum being logged by another task that is logging another * file which happens to refer to the same extent as well. Such races * can leave checksum items in the log with overlapping ranges. */ ret = lock_extent_bits(&log_root->log_csum_range, sums->bytenr, lock_end, &cached_state); if (ret) return ret; /* * Due to extent cloning, we might have logged a csum item that covers a * subrange of a cloned extent, and later we can end up logging a csum * item for a larger subrange of the same extent or the entire range. * This would leave csum items in the log tree that cover the same range * and break the searches for checksums in the log tree, resulting in * some checksums missing in the fs/subvolume tree. So just delete (or * trim and adjust) any existing csum items in the log for this range. */ ret = btrfs_del_csums(trans, log_root, sums->bytenr, sums->len); if (!ret) ret = btrfs_csum_file_blocks(trans, log_root, sums); unlock_extent_cached(&log_root->log_csum_range, sums->bytenr, lock_end, &cached_state); return ret; } static noinline int copy_items(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_path *dst_path, struct btrfs_path *src_path, int start_slot, int nr, int inode_only, u64 logged_isize) { struct btrfs_fs_info *fs_info = trans->fs_info; unsigned long src_offset; unsigned long dst_offset; struct btrfs_root *log = inode->root->log_root; struct btrfs_file_extent_item *extent; struct btrfs_inode_item *inode_item; struct extent_buffer *src = src_path->nodes[0]; int ret; struct btrfs_key *ins_keys; u32 *ins_sizes; char *ins_data; int i; struct list_head ordered_sums; int skip_csum = inode->flags & BTRFS_INODE_NODATASUM; INIT_LIST_HEAD(&ordered_sums); ins_data = kmalloc(nr * sizeof(struct btrfs_key) + nr * sizeof(u32), GFP_NOFS); if (!ins_data) return -ENOMEM; ins_sizes = (u32 *)ins_data; ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32)); for (i = 0; i < nr; i++) { ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot); btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot); } ret = btrfs_insert_empty_items(trans, log, dst_path, ins_keys, ins_sizes, nr); if (ret) { kfree(ins_data); return ret; } for (i = 0; i < nr; i++, dst_path->slots[0]++) { dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], dst_path->slots[0]); src_offset = btrfs_item_ptr_offset(src, start_slot + i); if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) { inode_item = btrfs_item_ptr(dst_path->nodes[0], dst_path->slots[0], struct btrfs_inode_item); fill_inode_item(trans, dst_path->nodes[0], inode_item, &inode->vfs_inode, inode_only == LOG_INODE_EXISTS, logged_isize); } else { copy_extent_buffer(dst_path->nodes[0], src, dst_offset, src_offset, ins_sizes[i]); } /* take a reference on file data extents so that truncates * or deletes of this inode don't have to relog the inode * again */ if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY && !skip_csum) { int found_type; extent = btrfs_item_ptr(src, start_slot + i, struct btrfs_file_extent_item); if (btrfs_file_extent_generation(src, extent) < trans->transid) continue; found_type = btrfs_file_extent_type(src, extent); if (found_type == BTRFS_FILE_EXTENT_REG) { u64 ds, dl, cs, cl; ds = btrfs_file_extent_disk_bytenr(src, extent); /* ds == 0 is a hole */ if (ds == 0) continue; dl = btrfs_file_extent_disk_num_bytes(src, extent); cs = btrfs_file_extent_offset(src, extent); cl = btrfs_file_extent_num_bytes(src, extent); if (btrfs_file_extent_compression(src, extent)) { cs = 0; cl = dl; } ret = btrfs_lookup_csums_range( fs_info->csum_root, ds + cs, ds + cs + cl - 1, &ordered_sums, 0); if (ret) break; } } } btrfs_mark_buffer_dirty(dst_path->nodes[0]); btrfs_release_path(dst_path); kfree(ins_data); /* * we have to do this after the loop above to avoid changing the * log tree while trying to change the log tree. */ while (!list_empty(&ordered_sums)) { struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next, struct btrfs_ordered_sum, list); if (!ret) ret = log_csums(trans, inode, log, sums); list_del(&sums->list); kfree(sums); } return ret; } static int extent_cmp(void *priv, const struct list_head *a, const struct list_head *b) { const struct extent_map *em1, *em2; em1 = list_entry(a, struct extent_map, list); em2 = list_entry(b, struct extent_map, list); if (em1->start < em2->start) return -1; else if (em1->start > em2->start) return 1; return 0; } static int log_extent_csums(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_root *log_root, const struct extent_map *em, struct btrfs_log_ctx *ctx) { struct btrfs_ordered_extent *ordered; u64 csum_offset; u64 csum_len; u64 mod_start = em->mod_start; u64 mod_len = em->mod_len; LIST_HEAD(ordered_sums); int ret = 0; if (inode->flags & BTRFS_INODE_NODATASUM || test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || em->block_start == EXTENT_MAP_HOLE) return 0; list_for_each_entry(ordered, &ctx->ordered_extents, log_list) { const u64 ordered_end = ordered->file_offset + ordered->num_bytes; const u64 mod_end = mod_start + mod_len; struct btrfs_ordered_sum *sums; if (mod_len == 0) break; if (ordered_end <= mod_start) continue; if (mod_end <= ordered->file_offset) break; /* * We are going to copy all the csums on this ordered extent, so * go ahead and adjust mod_start and mod_len in case this ordered * extent has already been logged. */ if (ordered->file_offset > mod_start) { if (ordered_end >= mod_end) mod_len = ordered->file_offset - mod_start; /* * If we have this case * * |--------- logged extent ---------| * |----- ordered extent ----| * * Just don't mess with mod_start and mod_len, we'll * just end up logging more csums than we need and it * will be ok. */ } else { if (ordered_end < mod_end) { mod_len = mod_end - ordered_end; mod_start = ordered_end; } else { mod_len = 0; } } /* * To keep us from looping for the above case of an ordered * extent that falls inside of the logged extent. */ if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags)) continue; list_for_each_entry(sums, &ordered->list, list) { ret = log_csums(trans, inode, log_root, sums); if (ret) return ret; } } /* We're done, found all csums in the ordered extents. */ if (mod_len == 0) return 0; /* If we're compressed we have to save the entire range of csums. */ if (em->compress_type) { csum_offset = 0; csum_len = max(em->block_len, em->orig_block_len); } else { csum_offset = mod_start - em->start; csum_len = mod_len; } /* block start is already adjusted for the file extent offset. */ ret = btrfs_lookup_csums_range(trans->fs_info->csum_root, em->block_start + csum_offset, em->block_start + csum_offset + csum_len - 1, &ordered_sums, 0); if (ret) return ret; while (!list_empty(&ordered_sums)) { struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next, struct btrfs_ordered_sum, list); if (!ret) ret = log_csums(trans, inode, log_root, sums); list_del(&sums->list); kfree(sums); } return ret; } static int log_one_extent(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_root *root, const struct extent_map *em, struct btrfs_path *path, struct btrfs_log_ctx *ctx) { struct btrfs_drop_extents_args drop_args = { 0 }; struct btrfs_root *log = root->log_root; struct btrfs_file_extent_item *fi; struct extent_buffer *leaf; struct btrfs_map_token token; struct btrfs_key key; u64 extent_offset = em->start - em->orig_start; u64 block_len; int ret; ret = log_extent_csums(trans, inode, log, em, ctx); if (ret) return ret; drop_args.path = path; drop_args.start = em->start; drop_args.end = em->start + em->len; drop_args.replace_extent = true; drop_args.extent_item_size = sizeof(*fi); ret = btrfs_drop_extents(trans, log, inode, &drop_args); if (ret) return ret; if (!drop_args.extent_inserted) { key.objectid = btrfs_ino(inode); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = em->start; ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*fi)); if (ret) return ret; } leaf = path->nodes[0]; btrfs_init_map_token(&token, leaf); fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_token_file_extent_generation(&token, fi, trans->transid); if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) btrfs_set_token_file_extent_type(&token, fi, BTRFS_FILE_EXTENT_PREALLOC); else btrfs_set_token_file_extent_type(&token, fi, BTRFS_FILE_EXTENT_REG); block_len = max(em->block_len, em->orig_block_len); if (em->compress_type != BTRFS_COMPRESS_NONE) { btrfs_set_token_file_extent_disk_bytenr(&token, fi, em->block_start); btrfs_set_token_file_extent_disk_num_bytes(&token, fi, block_len); } else if (em->block_start < EXTENT_MAP_LAST_BYTE) { btrfs_set_token_file_extent_disk_bytenr(&token, fi, em->block_start - extent_offset); btrfs_set_token_file_extent_disk_num_bytes(&token, fi, block_len); } else { btrfs_set_token_file_extent_disk_bytenr(&token, fi, 0); btrfs_set_token_file_extent_disk_num_bytes(&token, fi, 0); } btrfs_set_token_file_extent_offset(&token, fi, extent_offset); btrfs_set_token_file_extent_num_bytes(&token, fi, em->len); btrfs_set_token_file_extent_ram_bytes(&token, fi, em->ram_bytes); btrfs_set_token_file_extent_compression(&token, fi, em->compress_type); btrfs_set_token_file_extent_encryption(&token, fi, 0); btrfs_set_token_file_extent_other_encoding(&token, fi, 0); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(path); return ret; } /* * Log all prealloc extents beyond the inode's i_size to make sure we do not * lose them after doing a fast fsync and replaying the log. We scan the * subvolume's root instead of iterating the inode's extent map tree because * otherwise we can log incorrect extent items based on extent map conversion. * That can happen due to the fact that extent maps are merged when they * are not in the extent map tree's list of modified extents. */ static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_path *path) { struct btrfs_root *root = inode->root; struct btrfs_key key; const u64 i_size = i_size_read(&inode->vfs_inode); const u64 ino = btrfs_ino(inode); struct btrfs_path *dst_path = NULL; bool dropped_extents = false; u64 truncate_offset = i_size; struct extent_buffer *leaf; int slot; int ins_nr = 0; int start_slot; int ret; if (!(inode->flags & BTRFS_INODE_PREALLOC)) return 0; key.objectid = ino; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = i_size; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; /* * We must check if there is a prealloc extent that starts before the * i_size and crosses the i_size boundary. This is to ensure later we * truncate down to the end of that extent and not to the i_size, as * otherwise we end up losing part of the prealloc extent after a log * replay and with an implicit hole if there is another prealloc extent * that starts at an offset beyond i_size. */ ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY); if (ret < 0) goto out; if (ret == 0) { struct btrfs_file_extent_item *ei; leaf = path->nodes[0]; slot = path->slots[0]; ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, ei) == BTRFS_FILE_EXTENT_PREALLOC) { u64 extent_end; btrfs_item_key_to_cpu(leaf, &key, slot); extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, ei); if (extent_end > i_size) truncate_offset = extent_end; } } else { ret = 0; } while (true) { leaf = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(leaf)) { if (ins_nr > 0) { ret = copy_items(trans, inode, dst_path, path, start_slot, ins_nr, 1, 0); if (ret < 0) goto out; ins_nr = 0; } ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; if (ret > 0) { ret = 0; break; } continue; } btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid > ino) break; if (WARN_ON_ONCE(key.objectid < ino) || key.type < BTRFS_EXTENT_DATA_KEY || key.offset < i_size) { path->slots[0]++; continue; } if (!dropped_extents) { /* * Avoid logging extent items logged in past fsync calls * and leading to duplicate keys in the log tree. */ ret = truncate_inode_items(trans, root->log_root, inode, truncate_offset, BTRFS_EXTENT_DATA_KEY); if (ret) goto out; dropped_extents = true; } if (ins_nr == 0) start_slot = slot; ins_nr++; path->slots[0]++; if (!dst_path) { dst_path = btrfs_alloc_path(); if (!dst_path) { ret = -ENOMEM; goto out; } } } if (ins_nr > 0) ret = copy_items(trans, inode, dst_path, path, start_slot, ins_nr, 1, 0); out: btrfs_release_path(path); btrfs_free_path(dst_path); return ret; } static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, struct btrfs_path *path, struct btrfs_log_ctx *ctx) { struct btrfs_ordered_extent *ordered; struct btrfs_ordered_extent *tmp; struct extent_map *em, *n; struct list_head extents; struct extent_map_tree *tree = &inode->extent_tree; int ret = 0; int num = 0; INIT_LIST_HEAD(&extents); write_lock(&tree->lock); list_for_each_entry_safe(em, n, &tree->modified_extents, list) { list_del_init(&em->list); /* * Just an arbitrary number, this can be really CPU intensive * once we start getting a lot of extents, and really once we * have a bunch of extents we just want to commit since it will * be faster. */ if (++num > 32768) { list_del_init(&tree->modified_extents); ret = -EFBIG; goto process; } if (em->generation < trans->transid) continue; /* We log prealloc extents beyond eof later. */ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && em->start >= i_size_read(&inode->vfs_inode)) continue; /* Need a ref to keep it from getting evicted from cache */ refcount_inc(&em->refs); set_bit(EXTENT_FLAG_LOGGING, &em->flags); list_add_tail(&em->list, &extents); num++; } list_sort(NULL, &extents, extent_cmp); process: while (!list_empty(&extents)) { em = list_entry(extents.next, struct extent_map, list); list_del_init(&em->list); /* * If we had an error we just need to delete everybody from our * private list. */ if (ret) { clear_em_logging(tree, em); free_extent_map(em); continue; } write_unlock(&tree->lock); ret = log_one_extent(trans, inode, root, em, path, ctx); write_lock(&tree->lock); clear_em_logging(tree, em); free_extent_map(em); } WARN_ON(!list_empty(&extents)); write_unlock(&tree->lock); btrfs_release_path(path); if (!ret) ret = btrfs_log_prealloc_extents(trans, inode, path); if (ret) return ret; /* * We have logged all extents successfully, now make sure the commit of * the current transaction waits for the ordered extents to complete * before it commits and wipes out the log trees, otherwise we would * lose data if an ordered extents completes after the transaction * commits and a power failure happens after the transaction commit. */ list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) { list_del_init(&ordered->log_list); set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags); if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) { spin_lock_irq(&inode->ordered_tree.lock); if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) { set_bit(BTRFS_ORDERED_PENDING, &ordered->flags); atomic_inc(&trans->transaction->pending_ordered); } spin_unlock_irq(&inode->ordered_tree.lock); } btrfs_put_ordered_extent(ordered); } return 0; } static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode, struct btrfs_path *path, u64 *size_ret) { struct btrfs_key key; int ret; key.objectid = btrfs_ino(inode); key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, log, &key, path, 0, 0); if (ret < 0) { return ret; } else if (ret > 0) { *size_ret = 0; } else { struct btrfs_inode_item *item; item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); *size_ret = btrfs_inode_size(path->nodes[0], item); /* * If the in-memory inode's i_size is smaller then the inode * size stored in the btree, return the inode's i_size, so * that we get a correct inode size after replaying the log * when before a power failure we had a shrinking truncate * followed by addition of a new name (rename / new hard link). * Otherwise return the inode size from the btree, to avoid * data loss when replaying a log due to previously doing a * write that expands the inode's size and logging a new name * immediately after. */ if (*size_ret > inode->vfs_inode.i_size) *size_ret = inode->vfs_inode.i_size; } btrfs_release_path(path); return 0; } /* * At the moment we always log all xattrs. This is to figure out at log replay * time which xattrs must have their deletion replayed. If a xattr is missing * in the log tree and exists in the fs/subvol tree, we delete it. This is * because if a xattr is deleted, the inode is fsynced and a power failure * happens, causing the log to be replayed the next time the fs is mounted, * we want the xattr to not exist anymore (same behaviour as other filesystems * with a journal, ext3/4, xfs, f2fs, etc). */ static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, struct btrfs_path *path, struct btrfs_path *dst_path) { int ret; struct btrfs_key key; const u64 ino = btrfs_ino(inode); int ins_nr = 0; int start_slot = 0; bool found_xattrs = false; if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags)) return 0; key.objectid = ino; key.type = BTRFS_XATTR_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) return ret; while (true) { int slot = path->slots[0]; struct extent_buffer *leaf = path->nodes[0]; int nritems = btrfs_header_nritems(leaf); if (slot >= nritems) { if (ins_nr > 0) { ret = copy_items(trans, inode, dst_path, path, start_slot, ins_nr, 1, 0); if (ret < 0) return ret; ins_nr = 0; } ret = btrfs_next_leaf(root, path); if (ret < 0) return ret; else if (ret > 0) break; continue; } btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) break; if (ins_nr == 0) start_slot = slot; ins_nr++; path->slots[0]++; found_xattrs = true; cond_resched(); } if (ins_nr > 0) { ret = copy_items(trans, inode, dst_path, path, start_slot, ins_nr, 1, 0); if (ret < 0) return ret; } if (!found_xattrs) set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags); return 0; } /* * When using the NO_HOLES feature if we punched a hole that causes the * deletion of entire leafs or all the extent items of the first leaf (the one * that contains the inode item and references) we may end up not processing * any extents, because there are no leafs with a generation matching the * current transaction that have extent items for our inode. So we need to find * if any holes exist and then log them. We also need to log holes after any * truncate operation that changes the inode's size. */ static int btrfs_log_holes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, struct btrfs_path *path) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_key key; const u64 ino = btrfs_ino(inode); const u64 i_size = i_size_read(&inode->vfs_inode); u64 prev_extent_end = 0; int ret; if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0) return 0; key.objectid = ino; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) return ret; while (true) { struct extent_buffer *leaf = path->nodes[0]; if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { ret = btrfs_next_leaf(root, path); if (ret < 0) return ret; if (ret > 0) { ret = 0; break; } leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) break; /* We have a hole, log it. */ if (prev_extent_end < key.offset) { const u64 hole_len = key.offset - prev_extent_end; /* * Release the path to avoid deadlocks with other code * paths that search the root while holding locks on * leafs from the log root. */ btrfs_release_path(path); ret = btrfs_insert_file_extent(trans, root->log_root, ino, prev_extent_end, 0, 0, hole_len, 0, hole_len, 0, 0, 0); if (ret < 0) return ret; /* * Search for the same key again in the root. Since it's * an extent item and we are holding the inode lock, the * key must still exist. If it doesn't just emit warning * and return an error to fall back to a transaction * commit. */ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) return ret; if (WARN_ON(ret > 0)) return -ENOENT; leaf = path->nodes[0]; } prev_extent_end = btrfs_file_extent_end(path); path->slots[0]++; cond_resched(); } if (prev_extent_end < i_size) { u64 hole_len; btrfs_release_path(path); hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize); ret = btrfs_insert_file_extent(trans, root->log_root, ino, prev_extent_end, 0, 0, hole_len, 0, hole_len, 0, 0, 0); if (ret < 0) return ret; } return 0; } /* * When we are logging a new inode X, check if it doesn't have a reference that * matches the reference from some other inode Y created in a past transaction * and that was renamed in the current transaction. If we don't do this, then at * log replay time we can lose inode Y (and all its files if it's a directory): * * mkdir /mnt/x * echo "hello world" > /mnt/x/foobar * sync * mv /mnt/x /mnt/y * mkdir /mnt/x # or touch /mnt/x * xfs_io -c fsync /mnt/x * * mount fs, trigger log replay * * After the log replay procedure, we would lose the first directory and all its * files (file foobar). * For the case where inode Y is not a directory we simply end up losing it: * * echo "123" > /mnt/foo * sync * mv /mnt/foo /mnt/bar * echo "abc" > /mnt/foo * xfs_io -c fsync /mnt/foo * * * We also need this for cases where a snapshot entry is replaced by some other * entry (file or directory) otherwise we end up with an unreplayable log due to * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as * if it were a regular entry: * * mkdir /mnt/x * btrfs subvolume snapshot /mnt /mnt/x/snap * btrfs subvolume delete /mnt/x/snap * rmdir /mnt/x * mkdir /mnt/x * fsync /mnt/x or fsync some new file inside it * * * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in * the same transaction. */ static int btrfs_check_ref_name_override(struct extent_buffer *eb, const int slot, const struct btrfs_key *key, struct btrfs_inode *inode, u64 *other_ino, u64 *other_parent) { int ret; struct btrfs_path *search_path; char *name = NULL; u32 name_len = 0; u32 item_size = btrfs_item_size_nr(eb, slot); u32 cur_offset = 0; unsigned long ptr = btrfs_item_ptr_offset(eb, slot); search_path = btrfs_alloc_path(); if (!search_path) return -ENOMEM; search_path->search_commit_root = 1; search_path->skip_locking = 1; while (cur_offset < item_size) { u64 parent; u32 this_name_len; u32 this_len; unsigned long name_ptr; struct btrfs_dir_item *di; if (key->type == BTRFS_INODE_REF_KEY) { struct btrfs_inode_ref *iref; iref = (struct btrfs_inode_ref *)(ptr + cur_offset); parent = key->offset; this_name_len = btrfs_inode_ref_name_len(eb, iref); name_ptr = (unsigned long)(iref + 1); this_len = sizeof(*iref) + this_name_len; } else { struct btrfs_inode_extref *extref; extref = (struct btrfs_inode_extref *)(ptr + cur_offset); parent = btrfs_inode_extref_parent(eb, extref); this_name_len = btrfs_inode_extref_name_len(eb, extref); name_ptr = (unsigned long)&extref->name; this_len = sizeof(*extref) + this_name_len; } if (this_name_len > name_len) { char *new_name; new_name = krealloc(name, this_name_len, GFP_NOFS); if (!new_name) { ret = -ENOMEM; goto out; } name_len = this_name_len; name = new_name; } read_extent_buffer(eb, name, name_ptr, this_name_len); di = btrfs_lookup_dir_item(NULL, inode->root, search_path, parent, name, this_name_len, 0); if (di && !IS_ERR(di)) { struct btrfs_key di_key; btrfs_dir_item_key_to_cpu(search_path->nodes[0], di, &di_key); if (di_key.type == BTRFS_INODE_ITEM_KEY) { if (di_key.objectid != key->objectid) { ret = 1; *other_ino = di_key.objectid; *other_parent = parent; } else { ret = 0; } } else { ret = -EAGAIN; } goto out; } else if (IS_ERR(di)) { ret = PTR_ERR(di); goto out; } btrfs_release_path(search_path); cur_offset += this_len; } ret = 0; out: btrfs_free_path(search_path); kfree(name); return ret; } struct btrfs_ino_list { u64 ino; u64 parent; struct list_head list; }; static int log_conflicting_inodes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_log_ctx *ctx, u64 ino, u64 parent) { struct btrfs_ino_list *ino_elem; LIST_HEAD(inode_list); int ret = 0; ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS); if (!ino_elem) return -ENOMEM; ino_elem->ino = ino; ino_elem->parent = parent; list_add_tail(&ino_elem->list, &inode_list); while (!list_empty(&inode_list)) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_key key; struct inode *inode; ino_elem = list_first_entry(&inode_list, struct btrfs_ino_list, list); ino = ino_elem->ino; parent = ino_elem->parent; list_del(&ino_elem->list); kfree(ino_elem); if (ret) continue; btrfs_release_path(path); inode = btrfs_iget(fs_info->sb, ino, root); /* * If the other inode that had a conflicting dir entry was * deleted in the current transaction, we need to log its parent * directory. */ if (IS_ERR(inode)) { ret = PTR_ERR(inode); if (ret == -ENOENT) { inode = btrfs_iget(fs_info->sb, parent, root); if (IS_ERR(inode)) { ret = PTR_ERR(inode); } else { ret = btrfs_log_inode(trans, root, BTRFS_I(inode), LOG_OTHER_INODE_ALL, ctx); btrfs_add_delayed_iput(inode); } } continue; } /* * If the inode was already logged skip it - otherwise we can * hit an infinite loop. Example: * * From the commit root (previous transaction) we have the * following inodes: * * inode 257 a directory * inode 258 with references "zz" and "zz_link" on inode 257 * inode 259 with reference "a" on inode 257 * * And in the current (uncommitted) transaction we have: * * inode 257 a directory, unchanged * inode 258 with references "a" and "a2" on inode 257 * inode 259 with reference "zz_link" on inode 257 * inode 261 with reference "zz" on inode 257 * * When logging inode 261 the following infinite loop could * happen if we don't skip already logged inodes: * * - we detect inode 258 as a conflicting inode, with inode 261 * on reference "zz", and log it; * * - we detect inode 259 as a conflicting inode, with inode 258 * on reference "a", and log it; * * - we detect inode 258 as a conflicting inode, with inode 259 * on reference "zz_link", and log it - again! After this we * repeat the above steps forever. */ spin_lock(&BTRFS_I(inode)->lock); /* * Check the inode's logged_trans only instead of * btrfs_inode_in_log(). This is because the last_log_commit of * the inode is not updated when we only log that it exists (see * btrfs_log_inode()). */ if (BTRFS_I(inode)->logged_trans == trans->transid) { spin_unlock(&BTRFS_I(inode)->lock); btrfs_add_delayed_iput(inode); continue; } spin_unlock(&BTRFS_I(inode)->lock); /* * We are safe logging the other inode without acquiring its * lock as long as we log with the LOG_INODE_EXISTS mode. We * are safe against concurrent renames of the other inode as * well because during a rename we pin the log and update the * log with the new name before we unpin it. */ ret = btrfs_log_inode(trans, root, BTRFS_I(inode), LOG_OTHER_INODE, ctx); if (ret) { btrfs_add_delayed_iput(inode); continue; } key.objectid = ino; key.type = BTRFS_INODE_REF_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) { btrfs_add_delayed_iput(inode); continue; } while (true) { struct extent_buffer *leaf = path->nodes[0]; int slot = path->slots[0]; u64 other_ino = 0; u64 other_parent = 0; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) { break; } else if (ret > 0) { ret = 0; break; } continue; } btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid != ino || (key.type != BTRFS_INODE_REF_KEY && key.type != BTRFS_INODE_EXTREF_KEY)) { ret = 0; break; } ret = btrfs_check_ref_name_override(leaf, slot, &key, BTRFS_I(inode), &other_ino, &other_parent); if (ret < 0) break; if (ret > 0) { ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS); if (!ino_elem) { ret = -ENOMEM; break; } ino_elem->ino = other_ino; ino_elem->parent = other_parent; list_add_tail(&ino_elem->list, &inode_list); ret = 0; } path->slots[0]++; } btrfs_add_delayed_iput(inode); } return ret; } static int copy_inode_items_to_log(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_key *min_key, const struct btrfs_key *max_key, struct btrfs_path *path, struct btrfs_path *dst_path, const u64 logged_isize, const bool recursive_logging, const int inode_only, struct btrfs_log_ctx *ctx, bool *need_log_inode_item) { struct btrfs_root *root = inode->root; int ins_start_slot = 0; int ins_nr = 0; int ret; while (1) { ret = btrfs_search_forward(root, min_key, path, trans->transid); if (ret < 0) return ret; if (ret > 0) { ret = 0; break; } again: /* Note, ins_nr might be > 0 here, cleanup outside the loop */ if (min_key->objectid != max_key->objectid) break; if (min_key->type > max_key->type) break; if (min_key->type == BTRFS_INODE_ITEM_KEY) *need_log_inode_item = false; if ((min_key->type == BTRFS_INODE_REF_KEY || min_key->type == BTRFS_INODE_EXTREF_KEY) && inode->generation == trans->transid && !recursive_logging) { u64 other_ino = 0; u64 other_parent = 0; ret = btrfs_check_ref_name_override(path->nodes[0], path->slots[0], min_key, inode, &other_ino, &other_parent); if (ret < 0) { return ret; } else if (ret > 0 && other_ino != btrfs_ino(BTRFS_I(ctx->inode))) { if (ins_nr > 0) { ins_nr++; } else { ins_nr = 1; ins_start_slot = path->slots[0]; } ret = copy_items(trans, inode, dst_path, path, ins_start_slot, ins_nr, inode_only, logged_isize); if (ret < 0) return ret; ins_nr = 0; ret = log_conflicting_inodes(trans, root, path, ctx, other_ino, other_parent); if (ret) return ret; btrfs_release_path(path); goto next_key; } } /* Skip xattrs, we log them later with btrfs_log_all_xattrs() */ if (min_key->type == BTRFS_XATTR_ITEM_KEY) { if (ins_nr == 0) goto next_slot; ret = copy_items(trans, inode, dst_path, path, ins_start_slot, ins_nr, inode_only, logged_isize); if (ret < 0) return ret; ins_nr = 0; goto next_slot; } if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) { ins_nr++; goto next_slot; } else if (!ins_nr) { ins_start_slot = path->slots[0]; ins_nr = 1; goto next_slot; } ret = copy_items(trans, inode, dst_path, path, ins_start_slot, ins_nr, inode_only, logged_isize); if (ret < 0) return ret; ins_nr = 1; ins_start_slot = path->slots[0]; next_slot: path->slots[0]++; if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) { btrfs_item_key_to_cpu(path->nodes[0], min_key, path->slots[0]); goto again; } if (ins_nr) { ret = copy_items(trans, inode, dst_path, path, ins_start_slot, ins_nr, inode_only, logged_isize); if (ret < 0) return ret; ins_nr = 0; } btrfs_release_path(path); next_key: if (min_key->offset < (u64)-1) { min_key->offset++; } else if (min_key->type < max_key->type) { min_key->type++; min_key->offset = 0; } else { break; } } if (ins_nr) ret = copy_items(trans, inode, dst_path, path, ins_start_slot, ins_nr, inode_only, logged_isize); return ret; } /* log a single inode in the tree log. * At least one parent directory for this inode must exist in the tree * or be logged already. * * Any items from this inode changed by the current transaction are copied * to the log tree. An extra reference is taken on any extents in this * file, allowing us to avoid a whole pile of corner cases around logging * blocks that have been removed from the tree. * * See LOG_INODE_ALL and related defines for a description of what inode_only * does. * * This handles both files and directories. */ static int btrfs_log_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, int inode_only, struct btrfs_log_ctx *ctx) { struct btrfs_path *path; struct btrfs_path *dst_path; struct btrfs_key min_key; struct btrfs_key max_key; struct btrfs_root *log = root->log_root; int err = 0; int ret = 0; bool fast_search = false; u64 ino = btrfs_ino(inode); struct extent_map_tree *em_tree = &inode->extent_tree; u64 logged_isize = 0; bool need_log_inode_item = true; bool xattrs_logged = false; bool recursive_logging = false; bool inode_item_dropped = true; path = btrfs_alloc_path(); if (!path) return -ENOMEM; dst_path = btrfs_alloc_path(); if (!dst_path) { btrfs_free_path(path); return -ENOMEM; } min_key.objectid = ino; min_key.type = BTRFS_INODE_ITEM_KEY; min_key.offset = 0; max_key.objectid = ino; /* today the code can only do partial logging of directories */ if (S_ISDIR(inode->vfs_inode.i_mode) || (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) && inode_only >= LOG_INODE_EXISTS)) max_key.type = BTRFS_XATTR_ITEM_KEY; else max_key.type = (u8)-1; max_key.offset = (u64)-1; /* * Only run delayed items if we are a directory. We want to make sure * all directory indexes hit the fs/subvolume tree so we can find them * and figure out which index ranges have to be logged. * * Otherwise commit the delayed inode only if the full sync flag is set, * as we want to make sure an up to date version is in the subvolume * tree so copy_inode_items_to_log() / copy_items() can find it and copy * it to the log tree. For a non full sync, we always log the inode item * based on the in-memory struct btrfs_inode which is always up to date. */ if (S_ISDIR(inode->vfs_inode.i_mode)) ret = btrfs_commit_inode_delayed_items(trans, inode); else if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags)) ret = btrfs_commit_inode_delayed_inode(inode); if (ret) { btrfs_free_path(path); btrfs_free_path(dst_path); return ret; } if (inode_only == LOG_OTHER_INODE || inode_only == LOG_OTHER_INODE_ALL) { recursive_logging = true; if (inode_only == LOG_OTHER_INODE) inode_only = LOG_INODE_EXISTS; else inode_only = LOG_INODE_ALL; mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING); } else { mutex_lock(&inode->log_mutex); } /* * This is for cases where logging a directory could result in losing a * a file after replaying the log. For example, if we move a file from a * directory A to a directory B, then fsync directory A, we have no way * to known the file was moved from A to B, so logging just A would * result in losing the file after a log replay. */ if (S_ISDIR(inode->vfs_inode.i_mode) && inode_only == LOG_INODE_ALL && inode->last_unlink_trans >= trans->transid) { btrfs_set_log_full_commit(trans); err = 1; goto out_unlock; } /* * a brute force approach to making sure we get the most uptodate * copies of everything. */ if (S_ISDIR(inode->vfs_inode.i_mode)) { int max_key_type = BTRFS_DIR_LOG_INDEX_KEY; clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags); if (inode_only == LOG_INODE_EXISTS) max_key_type = BTRFS_XATTR_ITEM_KEY; ret = drop_inode_items(trans, log, path, inode, max_key_type); } else { if (inode_only == LOG_INODE_EXISTS) { /* * Make sure the new inode item we write to the log has * the same isize as the current one (if it exists). * This is necessary to prevent data loss after log * replay, and also to prevent doing a wrong expanding * truncate - for e.g. create file, write 4K into offset * 0, fsync, write 4K into offset 4096, add hard link, * fsync some other file (to sync log), power fail - if * we use the inode's current i_size, after log replay * we get a 8Kb file, with the last 4Kb extent as a hole * (zeroes), as if an expanding truncate happened, * instead of getting a file of 4Kb only. */ err = logged_inode_size(log, inode, path, &logged_isize); if (err) goto out_unlock; } if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags)) { if (inode_only == LOG_INODE_EXISTS) { max_key.type = BTRFS_XATTR_ITEM_KEY; ret = drop_inode_items(trans, log, path, inode, max_key.type); } else { clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags); clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags); if (inode_logged(trans, inode)) ret = truncate_inode_items(trans, log, inode, 0, 0); } } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags) || inode_only == LOG_INODE_EXISTS) { if (inode_only == LOG_INODE_ALL) fast_search = true; max_key.type = BTRFS_XATTR_ITEM_KEY; ret = drop_inode_items(trans, log, path, inode, max_key.type); } else { if (inode_only == LOG_INODE_ALL) fast_search = true; inode_item_dropped = false; goto log_extents; } } if (ret) { err = ret; goto out_unlock; } err = copy_inode_items_to_log(trans, inode, &min_key, &max_key, path, dst_path, logged_isize, recursive_logging, inode_only, ctx, &need_log_inode_item); if (err) goto out_unlock; btrfs_release_path(path); btrfs_release_path(dst_path); err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path); if (err) goto out_unlock; xattrs_logged = true; if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) { btrfs_release_path(path); btrfs_release_path(dst_path); err = btrfs_log_holes(trans, root, inode, path); if (err) goto out_unlock; } log_extents: btrfs_release_path(path); btrfs_release_path(dst_path); if (need_log_inode_item) { err = log_inode_item(trans, log, dst_path, inode, inode_item_dropped); if (err) goto out_unlock; /* * If we are doing a fast fsync and the inode was logged before * in this transaction, we don't need to log the xattrs because * they were logged before. If xattrs were added, changed or * deleted since the last time we logged the inode, then we have * already logged them because the inode had the runtime flag * BTRFS_INODE_COPY_EVERYTHING set. */ if (!xattrs_logged && inode->logged_trans < trans->transid) { err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path); if (err) goto out_unlock; btrfs_release_path(path); } } if (fast_search) { ret = btrfs_log_changed_extents(trans, root, inode, dst_path, ctx); if (ret) { err = ret; goto out_unlock; } } else if (inode_only == LOG_INODE_ALL) { struct extent_map *em, *n; write_lock(&em_tree->lock); list_for_each_entry_safe(em, n, &em_tree->modified_extents, list) list_del_init(&em->list); write_unlock(&em_tree->lock); } if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) { ret = log_directory_changes(trans, root, inode, path, dst_path, ctx); if (ret) { err = ret; goto out_unlock; } } spin_lock(&inode->lock); inode->logged_trans = trans->transid; /* * Don't update last_log_commit if we logged that an inode exists. * We do this for three reasons: * * 1) We might have had buffered writes to this inode that were * flushed and had their ordered extents completed in this * transaction, but we did not previously log the inode with * LOG_INODE_ALL. Later the inode was evicted and after that * it was loaded again and this LOG_INODE_EXISTS log operation * happened. We must make sure that if an explicit fsync against * the inode is performed later, it logs the new extents, an * updated inode item, etc, and syncs the log. The same logic * applies to direct IO writes instead of buffered writes. * * 2) When we log the inode with LOG_INODE_EXISTS, its inode item * is logged with an i_size of 0 or whatever value was logged * before. If later the i_size of the inode is increased by a * truncate operation, the log is synced through an fsync of * some other inode and then finally an explicit fsync against * this inode is made, we must make sure this fsync logs the * inode with the new i_size, the hole between old i_size and * the new i_size, and syncs the log. * * 3) If we are logging that an ancestor inode exists as part of * logging a new name from a link or rename operation, don't update * its last_log_commit - otherwise if an explicit fsync is made * against an ancestor, the fsync considers the inode in the log * and doesn't sync the log, resulting in the ancestor missing after * a power failure unless the log was synced as part of an fsync * against any other unrelated inode. */ if (inode_only != LOG_INODE_EXISTS) inode->last_log_commit = inode->last_sub_trans; spin_unlock(&inode->lock); out_unlock: mutex_unlock(&inode->log_mutex); btrfs_free_path(path); btrfs_free_path(dst_path); return err; } /* * Check if we need to log an inode. This is used in contexts where while * logging an inode we need to log another inode (either that it exists or in * full mode). This is used instead of btrfs_inode_in_log() because the later * requires the inode to be in the log and have the log transaction committed, * while here we do not care if the log transaction was already committed - our * caller will commit the log later - and we want to avoid logging an inode * multiple times when multiple tasks have joined the same log transaction. */ static bool need_log_inode(struct btrfs_trans_handle *trans, struct btrfs_inode *inode) { /* * If a directory was not modified, no dentries added or removed, we can * and should avoid logging it. */ if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid) return false; /* * If this inode does not have new/updated/deleted xattrs since the last * time it was logged and is flagged as logged in the current transaction, * we can skip logging it. As for new/deleted names, those are updated in * the log by link/unlink/rename operations. * In case the inode was logged and then evicted and reloaded, its * logged_trans will be 0, in which case we have to fully log it since * logged_trans is a transient field, not persisted. */ if (inode->logged_trans == trans->transid && !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags)) return false; return true; } struct btrfs_dir_list { u64 ino; struct list_head list; }; /* * Log the inodes of the new dentries of a directory. See log_dir_items() for * details about the why it is needed. * This is a recursive operation - if an existing dentry corresponds to a * directory, that directory's new entries are logged too (same behaviour as * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes * the dentries point to we do not lock their i_mutex, otherwise lockdep * complains about the following circular lock dependency / possible deadlock: * * CPU0 CPU1 * ---- ---- * lock(&type->i_mutex_dir_key#3/2); * lock(sb_internal#2); * lock(&type->i_mutex_dir_key#3/2); * lock(&sb->s_type->i_mutex_key#14); * * Where sb_internal is the lock (a counter that works as a lock) acquired by * sb_start_intwrite() in btrfs_start_transaction(). * Not locking i_mutex of the inodes is still safe because: * * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible * that while logging the inode new references (names) are added or removed * from the inode, leaving the logged inode item with a link count that does * not match the number of logged inode reference items. This is fine because * at log replay time we compute the real number of links and correct the * link count in the inode item (see replay_one_buffer() and * link_to_fixup_dir()); * * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that * while logging the inode's items new items with keys BTRFS_DIR_ITEM_KEY and * BTRFS_DIR_INDEX_KEY are added to fs/subvol tree and the logged inode item * has a size that doesn't match the sum of the lengths of all the logged * names. This does not result in a problem because if a dir_item key is * logged but its matching dir_index key is not logged, at log replay time we * don't use it to replay the respective name (see replay_one_name()). On the * other hand if only the dir_index key ends up being logged, the respective * name is added to the fs/subvol tree with both the dir_item and dir_index * keys created (see replay_one_name()). * The directory's inode item with a wrong i_size is not a problem as well, * since we don't use it at log replay time to set the i_size in the inode * item of the fs/subvol tree (see overwrite_item()). */ static int log_new_dir_dentries(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *start_inode, struct btrfs_log_ctx *ctx) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *log = root->log_root; struct btrfs_path *path; LIST_HEAD(dir_list); struct btrfs_dir_list *dir_elem; int ret = 0; /* * If we are logging a new name, as part of a link or rename operation, * don't bother logging new dentries, as we just want to log the names * of an inode and that any new parents exist. */ if (ctx->logging_new_name) return 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS); if (!dir_elem) { btrfs_free_path(path); return -ENOMEM; } dir_elem->ino = btrfs_ino(start_inode); list_add_tail(&dir_elem->list, &dir_list); while (!list_empty(&dir_list)) { struct extent_buffer *leaf; struct btrfs_key min_key; int nritems; int i; dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list, list); if (ret) goto next_dir_inode; min_key.objectid = dir_elem->ino; min_key.type = BTRFS_DIR_ITEM_KEY; min_key.offset = 0; again: btrfs_release_path(path); ret = btrfs_search_forward(log, &min_key, path, trans->transid); if (ret < 0) { goto next_dir_inode; } else if (ret > 0) { ret = 0; goto next_dir_inode; } process_leaf: leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); for (i = path->slots[0]; i < nritems; i++) { struct btrfs_dir_item *di; struct btrfs_key di_key; struct inode *di_inode; struct btrfs_dir_list *new_dir_elem; int log_mode = LOG_INODE_EXISTS; int type; btrfs_item_key_to_cpu(leaf, &min_key, i); if (min_key.objectid != dir_elem->ino || min_key.type != BTRFS_DIR_ITEM_KEY) goto next_dir_inode; di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item); type = btrfs_dir_type(leaf, di); if (btrfs_dir_transid(leaf, di) < trans->transid && type != BTRFS_FT_DIR) continue; btrfs_dir_item_key_to_cpu(leaf, di, &di_key); if (di_key.type == BTRFS_ROOT_ITEM_KEY) continue; btrfs_release_path(path); di_inode = btrfs_iget(fs_info->sb, di_key.objectid, root); if (IS_ERR(di_inode)) { ret = PTR_ERR(di_inode); goto next_dir_inode; } if (!need_log_inode(trans, BTRFS_I(di_inode))) { btrfs_add_delayed_iput(di_inode); break; } ctx->log_new_dentries = false; if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK) log_mode = LOG_INODE_ALL; ret = btrfs_log_inode(trans, root, BTRFS_I(di_inode), log_mode, ctx); btrfs_add_delayed_iput(di_inode); if (ret) goto next_dir_inode; if (ctx->log_new_dentries) { new_dir_elem = kmalloc(sizeof(*new_dir_elem), GFP_NOFS); if (!new_dir_elem) { ret = -ENOMEM; goto next_dir_inode; } new_dir_elem->ino = di_key.objectid; list_add_tail(&new_dir_elem->list, &dir_list); } break; } if (i == nritems) { ret = btrfs_next_leaf(log, path); if (ret < 0) { goto next_dir_inode; } else if (ret > 0) { ret = 0; goto next_dir_inode; } goto process_leaf; } if (min_key.offset < (u64)-1) { min_key.offset++; goto again; } next_dir_inode: list_del(&dir_elem->list); kfree(dir_elem); } btrfs_free_path(path); return ret; } static int btrfs_log_all_parents(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_log_ctx *ctx) { struct btrfs_fs_info *fs_info = trans->fs_info; int ret; struct btrfs_path *path; struct btrfs_key key; struct btrfs_root *root = inode->root; const u64 ino = btrfs_ino(inode); path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->skip_locking = 1; path->search_commit_root = 1; key.objectid = ino; key.type = BTRFS_INODE_REF_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; while (true) { struct extent_buffer *leaf = path->nodes[0]; int slot = path->slots[0]; u32 cur_offset = 0; u32 item_size; unsigned long ptr; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; else if (ret > 0) break; continue; } btrfs_item_key_to_cpu(leaf, &key, slot); /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */ if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY) break; item_size = btrfs_item_size_nr(leaf, slot); ptr = btrfs_item_ptr_offset(leaf, slot); while (cur_offset < item_size) { struct btrfs_key inode_key; struct inode *dir_inode; inode_key.type = BTRFS_INODE_ITEM_KEY; inode_key.offset = 0; if (key.type == BTRFS_INODE_EXTREF_KEY) { struct btrfs_inode_extref *extref; extref = (struct btrfs_inode_extref *) (ptr + cur_offset); inode_key.objectid = btrfs_inode_extref_parent( leaf, extref); cur_offset += sizeof(*extref); cur_offset += btrfs_inode_extref_name_len(leaf, extref); } else { inode_key.objectid = key.offset; cur_offset = item_size; } dir_inode = btrfs_iget(fs_info->sb, inode_key.objectid, root); /* * If the parent inode was deleted, return an error to * fallback to a transaction commit. This is to prevent * getting an inode that was moved from one parent A to * a parent B, got its former parent A deleted and then * it got fsync'ed, from existing at both parents after * a log replay (and the old parent still existing). * Example: * * mkdir /mnt/A * mkdir /mnt/B * touch /mnt/B/bar * sync * mv /mnt/B/bar /mnt/A/bar * mv -T /mnt/A /mnt/B * fsync /mnt/B/bar * * * If we ignore the old parent B which got deleted, * after a log replay we would have file bar linked * at both parents and the old parent B would still * exist. */ if (IS_ERR(dir_inode)) { ret = PTR_ERR(dir_inode); goto out; } if (!need_log_inode(trans, BTRFS_I(dir_inode))) { btrfs_add_delayed_iput(dir_inode); continue; } ctx->log_new_dentries = false; ret = btrfs_log_inode(trans, root, BTRFS_I(dir_inode), LOG_INODE_ALL, ctx); if (!ret && ctx->log_new_dentries) ret = log_new_dir_dentries(trans, root, BTRFS_I(dir_inode), ctx); btrfs_add_delayed_iput(dir_inode); if (ret) goto out; } path->slots[0]++; } ret = 0; out: btrfs_free_path(path); return ret; } static int log_new_ancestors(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_log_ctx *ctx) { struct btrfs_key found_key; btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); while (true) { struct btrfs_fs_info *fs_info = root->fs_info; struct extent_buffer *leaf = path->nodes[0]; int slot = path->slots[0]; struct btrfs_key search_key; struct inode *inode; u64 ino; int ret = 0; btrfs_release_path(path); ino = found_key.offset; search_key.objectid = found_key.offset; search_key.type = BTRFS_INODE_ITEM_KEY; search_key.offset = 0; inode = btrfs_iget(fs_info->sb, ino, root); if (IS_ERR(inode)) return PTR_ERR(inode); if (BTRFS_I(inode)->generation >= trans->transid && need_log_inode(trans, BTRFS_I(inode))) ret = btrfs_log_inode(trans, root, BTRFS_I(inode), LOG_INODE_EXISTS, ctx); btrfs_add_delayed_iput(inode); if (ret) return ret; if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID) break; search_key.type = BTRFS_INODE_REF_KEY; ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); if (ret < 0) return ret; leaf = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) return ret; else if (ret > 0) return -ENOENT; leaf = path->nodes[0]; slot = path->slots[0]; } btrfs_item_key_to_cpu(leaf, &found_key, slot); if (found_key.objectid != search_key.objectid || found_key.type != BTRFS_INODE_REF_KEY) return -ENOENT; } return 0; } static int log_new_ancestors_fast(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct dentry *parent, struct btrfs_log_ctx *ctx) { struct btrfs_root *root = inode->root; struct dentry *old_parent = NULL; struct super_block *sb = inode->vfs_inode.i_sb; int ret = 0; while (true) { if (!parent || d_really_is_negative(parent) || sb != parent->d_sb) break; inode = BTRFS_I(d_inode(parent)); if (root != inode->root) break; if (inode->generation >= trans->transid && need_log_inode(trans, inode)) { ret = btrfs_log_inode(trans, root, inode, LOG_INODE_EXISTS, ctx); if (ret) break; } if (IS_ROOT(parent)) break; parent = dget_parent(parent); dput(old_parent); old_parent = parent; } dput(old_parent); return ret; } static int log_all_new_ancestors(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct dentry *parent, struct btrfs_log_ctx *ctx) { struct btrfs_root *root = inode->root; const u64 ino = btrfs_ino(inode); struct btrfs_path *path; struct btrfs_key search_key; int ret; /* * For a single hard link case, go through a fast path that does not * need to iterate the fs/subvolume tree. */ if (inode->vfs_inode.i_nlink < 2) return log_new_ancestors_fast(trans, inode, parent, ctx); path = btrfs_alloc_path(); if (!path) return -ENOMEM; search_key.objectid = ino; search_key.type = BTRFS_INODE_REF_KEY; search_key.offset = 0; again: ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); if (ret < 0) goto out; if (ret == 0) path->slots[0]++; while (true) { struct extent_buffer *leaf = path->nodes[0]; int slot = path->slots[0]; struct btrfs_key found_key; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; else if (ret > 0) break; continue; } btrfs_item_key_to_cpu(leaf, &found_key, slot); if (found_key.objectid != ino || found_key.type > BTRFS_INODE_EXTREF_KEY) break; /* * Don't deal with extended references because they are rare * cases and too complex to deal with (we would need to keep * track of which subitem we are processing for each item in * this loop, etc). So just return some error to fallback to * a transaction commit. */ if (found_key.type == BTRFS_INODE_EXTREF_KEY) { ret = -EMLINK; goto out; } /* * Logging ancestors needs to do more searches on the fs/subvol * tree, so it releases the path as needed to avoid deadlocks. * Keep track of the last inode ref key and resume from that key * after logging all new ancestors for the current hard link. */ memcpy(&search_key, &found_key, sizeof(search_key)); ret = log_new_ancestors(trans, root, path, ctx); if (ret) goto out; btrfs_release_path(path); goto again; } ret = 0; out: btrfs_free_path(path); return ret; } /* * helper function around btrfs_log_inode to make sure newly created * parent directories also end up in the log. A minimal inode and backref * only logging is done of any parent directories that are older than * the last committed transaction */ static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct dentry *parent, int inode_only, struct btrfs_log_ctx *ctx) { struct btrfs_root *root = inode->root; struct btrfs_fs_info *fs_info = root->fs_info; int ret = 0; bool log_dentries = false; if (btrfs_test_opt(fs_info, NOTREELOG)) { ret = 1; goto end_no_trans; } if (btrfs_root_refs(&root->root_item) == 0) { ret = 1; goto end_no_trans; } /* * Skip already logged inodes or inodes corresponding to tmpfiles * (since logging them is pointless, a link count of 0 means they * will never be accessible). */ if ((btrfs_inode_in_log(inode, trans->transid) && list_empty(&ctx->ordered_extents)) || inode->vfs_inode.i_nlink == 0) { ret = BTRFS_NO_LOG_SYNC; goto end_no_trans; } ret = start_log_trans(trans, root, ctx); if (ret) goto end_no_trans; ret = btrfs_log_inode(trans, root, inode, inode_only, ctx); if (ret) goto end_trans; /* * for regular files, if its inode is already on disk, we don't * have to worry about the parents at all. This is because * we can use the last_unlink_trans field to record renames * and other fun in this file. */ if (S_ISREG(inode->vfs_inode.i_mode) && inode->generation < trans->transid && inode->last_unlink_trans < trans->transid) { ret = 0; goto end_trans; } if (S_ISDIR(inode->vfs_inode.i_mode) && ctx->log_new_dentries) log_dentries = true; /* * On unlink we must make sure all our current and old parent directory * inodes are fully logged. This is to prevent leaving dangling * directory index entries in directories that were our parents but are * not anymore. Not doing this results in old parent directory being * impossible to delete after log replay (rmdir will always fail with * error -ENOTEMPTY). * * Example 1: * * mkdir testdir * touch testdir/foo * ln testdir/foo testdir/bar * sync * unlink testdir/bar * xfs_io -c fsync testdir/foo * * mount fs, triggers log replay * * If we don't log the parent directory (testdir), after log replay the * directory still has an entry pointing to the file inode using the bar * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and * the file inode has a link count of 1. * * Example 2: * * mkdir testdir * touch foo * ln foo testdir/foo2 * ln foo testdir/foo3 * sync * unlink testdir/foo3 * xfs_io -c fsync foo * * mount fs, triggers log replay * * Similar as the first example, after log replay the parent directory * testdir still has an entry pointing to the inode file with name foo3 * but the file inode does not have a matching BTRFS_INODE_REF_KEY item * and has a link count of 2. */ if (inode->last_unlink_trans >= trans->transid) { ret = btrfs_log_all_parents(trans, inode, ctx); if (ret) goto end_trans; } ret = log_all_new_ancestors(trans, inode, parent, ctx); if (ret) goto end_trans; if (log_dentries) ret = log_new_dir_dentries(trans, root, inode, ctx); else ret = 0; end_trans: if (ret < 0) { btrfs_set_log_full_commit(trans); ret = 1; } if (ret) btrfs_remove_log_ctx(root, ctx); btrfs_end_log_trans(root); end_no_trans: return ret; } /* * it is not safe to log dentry if the chunk root has added new * chunks. This returns 0 if the dentry was logged, and 1 otherwise. * If this returns 1, you must commit the transaction to safely get your * data on disk. */ int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans, struct dentry *dentry, struct btrfs_log_ctx *ctx) { struct dentry *parent = dget_parent(dentry); int ret; ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent, LOG_INODE_ALL, ctx); dput(parent); return ret; } /* * should be called during mount to recover any replay any log trees * from the FS */ int btrfs_recover_log_trees(struct btrfs_root *log_root_tree) { int ret; struct btrfs_path *path; struct btrfs_trans_handle *trans; struct btrfs_key key; struct btrfs_key found_key; struct btrfs_root *log; struct btrfs_fs_info *fs_info = log_root_tree->fs_info; struct walk_control wc = { .process_func = process_one_buffer, .stage = LOG_WALK_PIN_ONLY, }; path = btrfs_alloc_path(); if (!path) return -ENOMEM; set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); trans = btrfs_start_transaction(fs_info->tree_root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto error; } wc.trans = trans; wc.pin = 1; ret = walk_log_tree(trans, log_root_tree, &wc); if (ret) { btrfs_handle_fs_error(fs_info, ret, "Failed to pin buffers while recovering log root tree."); goto error; } again: key.objectid = BTRFS_TREE_LOG_OBJECTID; key.offset = (u64)-1; key.type = BTRFS_ROOT_ITEM_KEY; while (1) { ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0); if (ret < 0) { btrfs_handle_fs_error(fs_info, ret, "Couldn't find tree log root."); goto error; } if (ret > 0) { if (path->slots[0] == 0) break; path->slots[0]--; } btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); btrfs_release_path(path); if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID) break; log = btrfs_read_tree_root(log_root_tree, &found_key); if (IS_ERR(log)) { ret = PTR_ERR(log); btrfs_handle_fs_error(fs_info, ret, "Couldn't read tree log root."); goto error; } wc.replay_dest = btrfs_get_fs_root(fs_info, found_key.offset, true); if (IS_ERR(wc.replay_dest)) { ret = PTR_ERR(wc.replay_dest); /* * We didn't find the subvol, likely because it was * deleted. This is ok, simply skip this log and go to * the next one. * * We need to exclude the root because we can't have * other log replays overwriting this log as we'll read * it back in a few more times. This will keep our * block from being modified, and we'll just bail for * each subsequent pass. */ if (ret == -ENOENT) ret = btrfs_pin_extent_for_log_replay(trans, log->node->start, log->node->len); btrfs_put_root(log); if (!ret) goto next; btrfs_handle_fs_error(fs_info, ret, "Couldn't read target root for tree log recovery."); goto error; } wc.replay_dest->log_root = log; ret = btrfs_record_root_in_trans(trans, wc.replay_dest); if (ret) /* The loop needs to continue due to the root refs */ btrfs_handle_fs_error(fs_info, ret, "failed to record the log root in transaction"); else ret = walk_log_tree(trans, log, &wc); if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) { ret = fixup_inode_link_counts(trans, wc.replay_dest, path); } if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) { struct btrfs_root *root = wc.replay_dest; btrfs_release_path(path); /* * We have just replayed everything, and the highest * objectid of fs roots probably has changed in case * some inode_item's got replayed. * * root->objectid_mutex is not acquired as log replay * could only happen during mount. */ ret = btrfs_init_root_free_objectid(root); } wc.replay_dest->log_root = NULL; btrfs_put_root(wc.replay_dest); btrfs_put_root(log); if (ret) goto error; next: if (found_key.offset == 0) break; key.offset = found_key.offset - 1; } btrfs_release_path(path); /* step one is to pin it all, step two is to replay just inodes */ if (wc.pin) { wc.pin = 0; wc.process_func = replay_one_buffer; wc.stage = LOG_WALK_REPLAY_INODES; goto again; } /* step three is to replay everything */ if (wc.stage < LOG_WALK_REPLAY_ALL) { wc.stage++; goto again; } btrfs_free_path(path); /* step 4: commit the transaction, which also unpins the blocks */ ret = btrfs_commit_transaction(trans); if (ret) return ret; log_root_tree->log_root = NULL; clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); btrfs_put_root(log_root_tree); return 0; error: if (wc.trans) btrfs_end_transaction(wc.trans); clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); btrfs_free_path(path); return ret; } /* * there are some corner cases where we want to force a full * commit instead of allowing a directory to be logged. * * They revolve around files there were unlinked from the directory, and * this function updates the parent directory so that a full commit is * properly done if it is fsync'd later after the unlinks are done. * * Must be called before the unlink operations (updates to the subvolume tree, * inodes, etc) are done. */ void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans, struct btrfs_inode *dir, struct btrfs_inode *inode, int for_rename) { /* * when we're logging a file, if it hasn't been renamed * or unlinked, and its inode is fully committed on disk, * we don't have to worry about walking up the directory chain * to log its parents. * * So, we use the last_unlink_trans field to put this transid * into the file. When the file is logged we check it and * don't log the parents if the file is fully on disk. */ mutex_lock(&inode->log_mutex); inode->last_unlink_trans = trans->transid; mutex_unlock(&inode->log_mutex); /* * if this directory was already logged any new * names for this file/dir will get recorded */ if (dir->logged_trans == trans->transid) return; /* * if the inode we're about to unlink was logged, * the log will be properly updated for any new names */ if (inode->logged_trans == trans->transid) return; /* * when renaming files across directories, if the directory * there we're unlinking from gets fsync'd later on, there's * no way to find the destination directory later and fsync it * properly. So, we have to be conservative and force commits * so the new name gets discovered. */ if (for_rename) goto record; /* we can safely do the unlink without any special recording */ return; record: mutex_lock(&dir->log_mutex); dir->last_unlink_trans = trans->transid; mutex_unlock(&dir->log_mutex); } /* * Make sure that if someone attempts to fsync the parent directory of a deleted * snapshot, it ends up triggering a transaction commit. This is to guarantee * that after replaying the log tree of the parent directory's root we will not * see the snapshot anymore and at log replay time we will not see any log tree * corresponding to the deleted snapshot's root, which could lead to replaying * it after replaying the log tree of the parent directory (which would replay * the snapshot delete operation). * * Must be called before the actual snapshot destroy operation (updates to the * parent root and tree of tree roots trees, etc) are done. */ void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans, struct btrfs_inode *dir) { mutex_lock(&dir->log_mutex); dir->last_unlink_trans = trans->transid; mutex_unlock(&dir->log_mutex); } /* * Call this after adding a new name for a file and it will properly * update the log to reflect the new name. */ void btrfs_log_new_name(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_inode *old_dir, struct dentry *parent) { struct btrfs_log_ctx ctx; /* * this will force the logging code to walk the dentry chain * up for the file */ if (!S_ISDIR(inode->vfs_inode.i_mode)) inode->last_unlink_trans = trans->transid; /* * if this inode hasn't been logged and directory we're renaming it * from hasn't been logged, we don't need to log it */ if (!inode_logged(trans, inode) && (!old_dir || !inode_logged(trans, old_dir))) return; /* * If we are doing a rename (old_dir is not NULL) from a directory that * was previously logged, make sure the next log attempt on the directory * is not skipped and logs the inode again. This is because the log may * not currently be authoritative for a range including the old * BTRFS_DIR_ITEM_KEY and BTRFS_DIR_INDEX_KEY keys, so we want to make * sure after a log replay we do not end up with both the new and old * dentries around (in case the inode is a directory we would have a * directory with two hard links and 2 inode references for different * parents). The next log attempt of old_dir will happen at * btrfs_log_all_parents(), called through btrfs_log_inode_parent() * below, because we have previously set inode->last_unlink_trans to the * current transaction ID, either here or at btrfs_record_unlink_dir() in * case inode is a directory. */ if (old_dir) old_dir->logged_trans = 0; btrfs_init_log_ctx(&ctx, &inode->vfs_inode); ctx.logging_new_name = true; /* * We don't care about the return value. If we fail to log the new name * then we know the next attempt to sync the log will fallback to a full * transaction commit (due to a call to btrfs_set_log_full_commit()), so * we don't need to worry about getting a log committed that has an * inconsistent state after a rename operation. */ btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx); }