From patchwork Mon Aug 22 10:51:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Filipe Manana X-Patchwork-Id: 12950491 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 393B8C32772 for ; Mon, 22 Aug 2022 10:52:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233924AbiHVKwI (ORCPT ); Mon, 22 Aug 2022 06:52:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233820AbiHVKwF (ORCPT ); Mon, 22 Aug 2022 06:52:05 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B5673123F for ; Mon, 22 Aug 2022 03:52:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DCF1160FDE for ; Mon, 22 Aug 2022 10:52:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6868C433D7 for ; Mon, 22 Aug 2022 10:52:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661165522; bh=H0ZdcpupSrmDYFdZf9zEJuGHq+bmtfqdwNnc914bOrw=; h=From:To:Subject:Date:In-Reply-To:References:From; b=LcUWqyYcSVMD1r9qWbUJfqLbgufh9r908bNR+s+bis/i84sXW6V4iYqU+kYkX56WL nxmMAJ4Afaqf/jH/y3NK3slCSI3QMmbAoUFQzoI41wb8KlAH4J1zXnZzzP4/IGZeTt vljBhgn/+0CltIrBi9ihmAVSI3APh7+HP3yXvbUDVoxG70F4uiDDS8onwnc2TF4Yzd V/FarQJZxROLYtHvyG9LMHF8v/J2r5mD9uxSgaE4bQEW8Rna+0upGUchdfdqr6PKii cUVWGepvXIkdoT6ExkUqxy/Yw6eGsDZIH7kjWAbF0eNnW/6NM+WZUI3FBc3uvQHjUM wjQzILHzUP29Q== From: fdmanana@kernel.org To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 15/15] btrfs: use delayed items when logging a directory Date: Mon, 22 Aug 2022 11:51:44 +0100 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Filipe Manana When logging a directory we start by flushing all its delayed items. That results in adding dir index items to the subvolume btree, for new dentries, and removing dir index items from the subvolume btree for any dentries that were deleted. This makes it straightforward to log a directory simply by iterating over all the modified subvolume btree leaves, especially when we used to log both dir index keys and dir item keys (before commit 339d035424849c ("btrfs: only copy dir index keys when logging a directory") and when we used to copy old dir index entries for leaves modified in the current transaction (before commit 732d591a5d6c12 ("btrfs: stop copying old dir items when logging a directory")). From an efficiency point of view this has a couple of drawbacks: 1) Adds extra latency, due to copying delayed items to the subvolume btree and deleting dir index items from the btree. Further if there are other tasks accessing the btree, which is common (syscalls like creat, mkdir, rename, link, unlink, truncate, reflinks, etc, finishing an ordered extent, etc), lock contention can cause further delays, both to the task logging a directory and to the other tasks accessing the btree; 2) More time spent overall flushing delayed items, if after logging the directory further changes are done to the directory in the same transaction. For example, if we add 10 dentries to a directory, fsync it, add more 10 dentries, fsync it again, then add more 10 dentries and fsync it again, then we end up inserting 3 batches of 10 items to the subvolume btree. With the changes from this patch, we flush all the delayed items to the btree only once - a single batch of 30 items, and outside the logging code (transaction commit or when delayed items are flushed asynchronously). This change simply skips the flushing of delayed items everytime we log a directory. Instead we copy the delayed insertion items directly to the log tree and delete delayed deletion items directly from the log tree. Therefore avoiding changing first the subvolume btree and then scanning it for new items to copy from it to the log tree and detecting deletions by observing gaps in consecutive dir index keys in subvolume btree leaves. Running the following tests on a non-debug kernel (Debian's default kernel config), on a box with a nvme device, a 12 cores Intel cpu and 64G of ram, produced the results below. The results compare a branch without this patch and all the other patches it depends on versus the same branch with the patchset applied. The patchset is comprised of the following patches: btrfs: don't drop dir index range items when logging a directory btrfs: remove the root argument from log_new_dir_dentries() btrfs: update stale comment for log_new_dir_dentries() btrfs: free list element sooner at log_new_dir_dentries() btrfs: avoid memory allocation at log_new_dir_dentries() for common case btrfs: remove root argument from btrfs_delayed_item_reserve_metadata() btrfs: store index number instead of key in struct btrfs_delayed_item btrfs: remove unused logic when looking up delayed items btrfs: shrink the size of struct btrfs_delayed_item btrfs: search for last logged dir index if it's not cached in the inode btrfs: move need_log_inode() to above log_conflicting_inodes() btrfs: move log_new_dir_dentries() above btrfs_log_inode() btrfs: log conflicting inodes without holding log mutex of the initial inode btrfs: skip logging parent dir when conflicting inode is not a dir btrfs: use delayed items when logging a directory Custom test script for testing time spent at btrfs_log_inode(): #!/bin/bash DEV=/dev/nvme0n1 MNT=/mnt/nvme0n1 # Total number of files to create in the test directory. NUM_FILES=10000 # Fsync after creating or renaming N files. FSYNC_AFTER=100 umount $DEV &> /dev/null mkfs.btrfs -f $DEV mount -o ssd $DEV $MNT TEST_DIR=$MNT/testdir mkdir $TEST_DIR echo "Creating files..." for ((i = 1; i <= $NUM_FILES; i++)); do echo -n > $TEST_DIR/file_$i if (( ($i % $FSYNC_AFTER) == 0 )); then xfs_io -c "fsync" $TEST_DIR fi done sync echo "Renaming files..." for ((i = 1; i <= $NUM_FILES; i++)); do mv $TEST_DIR/file_$i $TEST_DIR/file_$i.renamed if (( ($i % $FSYNC_AFTER) == 0 )); then xfs_io -c "fsync" $TEST_DIR fi done umount $MNT And using the following bpftrace script to capture the total time that is spent at btrfs_log_inode(): #!/usr/bin/bpftrace k:btrfs_log_inode { @start_log_inode[tid] = nsecs; } kr:btrfs_log_inode /@start_log_inode[tid]/ { $dur = (nsecs - @start_log_inode[tid]) / 1000; @btrfs_log_inode_total_time = sum($dur); delete(@start_log_inode[tid]); } END { clear(@start_log_inode); } Result before applying patchset: @btrfs_log_inode_total_time: 622642 Result after applying patchset: @btrfs_log_inode_total_time: 354134 (-43.1% time spent) The following dbench script was also used for testing: #!/bin/bash NUM_JOBS=$(nproc --all) DEV=/dev/nvme0n1 MNT=/mnt/nvme0n1 MOUNT_OPTIONS="-o ssd" MKFS_OPTIONS="-O no-holes -R free-space-tree" echo "performance" | \ tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor umount $DEV &> /dev/null mkfs.btrfs -f $MKFS_OPTIONS $DEV mount $MOUNT_OPTIONS $DEV $MNT dbench -D $MNT --skip-cleanup -t 120 -S $NUM_JOBS umount $MNT Before patchset: Operation Count AvgLat MaxLat ---------------------------------------- NTCreateX 3322265 0.034 21.032 Close 2440562 0.002 0.994 Rename 140664 1.150 269.633 Unlink 670796 1.093 269.678 Deltree 96 5.481 15.510 Mkdir 48 0.004 0.052 Qpathinfo 3010924 0.014 8.127 Qfileinfo 528055 0.001 0.518 Qfsinfo 552113 0.003 0.372 Sfileinfo 270575 0.005 0.688 Find 1164176 0.052 13.931 WriteX 1658537 0.019 5.918 ReadX 5207412 0.003 1.034 LockX 10818 0.003 0.079 UnlockX 10818 0.002 0.313 Flush 232811 1.027 269.735 Throughput 869.867 MB/sec (sync dirs) 12 clients 12 procs max_latency=269.741 ms After patchset: Operation Count AvgLat MaxLat ---------------------------------------- NTCreateX 4152738 0.029 20.863 Close 3050770 0.002 1.119 Rename 175829 0.871 211.741 Unlink 838447 0.845 211.724 Deltree 120 4.798 14.162 Mkdir 60 0.003 0.005 Qpathinfo 3763807 0.011 4.673 Qfileinfo 660111 0.001 0.400 Qfsinfo 690141 0.003 0.429 Sfileinfo 338260 0.005 0.725 Find 1455273 0.046 6.787 WriteX 2073307 0.017 5.690 ReadX 6509193 0.003 1.171 LockX 13522 0.003 0.077 UnlockX 13522 0.002 0.125 Flush 291044 0.811 211.631 Throughput 1089.27 MB/sec (sync dirs) 12 clients 12 procs max_latency=211.750 ms (+25.2% throughput, -21.5% max latency) Signed-off-by: Filipe Manana --- fs/btrfs/delayed-inode.c | 112 ++++++++++ fs/btrfs/delayed-inode.h | 19 ++ fs/btrfs/tree-log.c | 437 ++++++++++++++++++++++++++++++++++++++- fs/btrfs/tree-log.h | 2 + 4 files changed, 562 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c index b35eddcac846..cac5169eaf8d 100644 --- a/fs/btrfs/delayed-inode.c +++ b/fs/btrfs/delayed-inode.c @@ -315,6 +315,8 @@ static struct btrfs_delayed_item *btrfs_alloc_delayed_item(u16 data_len, item->bytes_reserved = 0; item->delayed_node = node; RB_CLEAR_NODE(&item->rb_node); + INIT_LIST_HEAD(&item->log_list); + item->logged = false; refcount_set(&item->refs, 1); } return item; @@ -2045,3 +2047,113 @@ void btrfs_destroy_delayed_inodes(struct btrfs_fs_info *fs_info) } } +void btrfs_log_get_delayed_items(struct btrfs_inode *inode, + struct list_head *ins_list, + struct list_head *del_list) +{ + struct btrfs_delayed_node *node; + struct btrfs_delayed_item *item; + + node = btrfs_get_delayed_node(inode); + if (!node) + return; + + mutex_lock(&node->mutex); + item = __btrfs_first_delayed_insertion_item(node); + while (item) { + /* + * It's possible that the item is already in a log list. This + * can happen in case two tasks are trying to log the same + * directory. For example if we have tasks A and task B: + * + * Task A collected the delayed items into a log list while + * under the inode's log_mutex (at btrfs_log_inode()), but it + * only releases the items after logging the inodes they point + * to (if they are new inodes), which happens after unlocking + * the log mutex; + * + * Task B enters btrfs_log_inode() and acquires the log_mutex + * of the same directory inode, before task B releases the + * delayed items. This can happen for example when logging some + * inode we need to trigger logging of its parent directory, so + * logging two files that have the same parent directory can + * lead to this. + * + * If this happens, just ignore delayed items already in a log + * list. All the tasks logging the directory are under a log + * transaction and whichever finishes first can not sync the log + * before the other completes and leaves the log transaction. + */ + if (!item->logged && list_empty(&item->log_list)) { + refcount_inc(&item->refs); + list_add_tail(&item->log_list, ins_list); + } + item = __btrfs_next_delayed_item(item); + } + + item = __btrfs_first_delayed_deletion_item(node); + while (item) { + /* It may be non-empty, for the same reason mentioned above. */ + if (!item->logged && list_empty(&item->log_list)) { + refcount_inc(&item->refs); + list_add_tail(&item->log_list, del_list); + } + item = __btrfs_next_delayed_item(item); + } + mutex_unlock(&node->mutex); + + /* + * We are called during inode logging, which means the inode is in use + * and can not be evicted before we finish logging the inode. So we never + * have the last reference on the delayed inode. + * Also, we don't use btrfs_release_delayed_node() because that would + * requeue the delayed inode (change its order in the list of prepared + * nodes) and we don't want to do such change because we don't create or + * delete delayed items. + */ + ASSERT(refcount_read(&node->refs) > 1); + refcount_dec(&node->refs); +} + +void btrfs_log_put_delayed_items(struct btrfs_inode *inode, + struct list_head *ins_list, + struct list_head *del_list) +{ + struct btrfs_delayed_node *node; + struct btrfs_delayed_item *item; + struct btrfs_delayed_item *next; + + node = btrfs_get_delayed_node(inode); + if (!node) + return; + + mutex_lock(&node->mutex); + + list_for_each_entry_safe(item, next, ins_list, log_list) { + item->logged = true; + list_del_init(&item->log_list); + if (refcount_dec_and_test(&item->refs)) + kfree(item); + } + + list_for_each_entry_safe(item, next, del_list, log_list) { + item->logged = true; + list_del_init(&item->log_list); + if (refcount_dec_and_test(&item->refs)) + kfree(item); + } + + mutex_unlock(&node->mutex); + + /* + * We are called during inode logging, which means the inode is in use + * and can not be evicted before we finish logging the inode. So we never + * have the last reference on the delayed inode. + * Also, we don't use btrfs_release_delayed_node() because that would + * requeue the delayed inode (change its order in the list of prepared + * nodes) and we don't want to do such change because we don't create or + * delete delayed items. + */ + ASSERT(refcount_read(&node->refs) > 1); + refcount_dec(&node->refs); +} diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h index 729d352ca8a1..e0699e360f49 100644 --- a/fs/btrfs/delayed-inode.h +++ b/fs/btrfs/delayed-inode.h @@ -78,10 +78,21 @@ struct btrfs_delayed_item { u64 index; struct list_head tree_list; /* used for batch insert/delete items */ struct list_head readdir_list; /* used for readdir items */ + /* + * Used when logging a directory. + * Insertions and deletions to this list are protected by the parent + * delayed node's mutex. + */ + struct list_head log_list; u64 bytes_reserved; struct btrfs_delayed_node *delayed_node; refcount_t refs; enum btrfs_delayed_item_type type:1; + /* + * Track if this delayed item was already logged. + * Protected by the mutex of the parent delayed inode. + */ + bool logged; /* The maximum leaf size is 64K, so u16 is more than enough. */ u16 data_len; char data[]; @@ -147,6 +158,14 @@ int btrfs_should_delete_dir_index(struct list_head *del_list, int btrfs_readdir_delayed_dir_index(struct dir_context *ctx, struct list_head *ins_list); +/* Used during directory logging. */ +void btrfs_log_get_delayed_items(struct btrfs_inode *inode, + struct list_head *ins_list, + struct list_head *del_list); +void btrfs_log_put_delayed_items(struct btrfs_inode *inode, + struct list_head *ins_list, + struct list_head *del_list); + /* for init */ int __init btrfs_delayed_inode_init(void); void __cold btrfs_delayed_inode_exit(void); diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 1d4c285bb26c..098d6cf01475 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -5918,6 +5918,371 @@ static int copy_inode_items_to_log(struct btrfs_trans_handle *trans, return ret; } +static int insert_delayed_items_batch(struct btrfs_trans_handle *trans, + struct btrfs_root *log, + struct btrfs_path *path, + const struct btrfs_item_batch *batch, + const struct btrfs_delayed_item *first_item) +{ + const struct btrfs_delayed_item *curr = first_item; + int ret; + + ret = btrfs_insert_empty_items(trans, log, path, batch); + if (ret) + return ret; + + for (int i = 0; i < batch->nr; i++) { + char *data_ptr; + + data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char); + write_extent_buffer(path->nodes[0], &curr->data, + (unsigned long)data_ptr, curr->data_len); + curr = list_next_entry(curr, log_list); + path->slots[0]++; + } + + btrfs_release_path(path); + + return 0; +} + +static int log_delayed_insertion_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_ins_list, + struct btrfs_log_ctx *ctx) +{ + /* 195 (4095 bytes of keys and sizes) fits in a single 4K page. */ + const int max_batch_size = 195; + const int leaf_data_size = BTRFS_LEAF_DATA_SIZE(trans->fs_info); + const u64 ino = btrfs_ino(inode); + struct btrfs_root *log = inode->root->log_root; + struct btrfs_item_batch batch = { + .nr = 0, + .total_data_size = 0, + }; + const struct btrfs_delayed_item *first = NULL; + const struct btrfs_delayed_item *curr; + char *ins_data; + struct btrfs_key *ins_keys; + u32 *ins_sizes; + u64 curr_batch_size = 0; + int batch_idx = 0; + int ret; + + /* We are adding dir index items to the log tree. */ + lockdep_assert_held(&inode->log_mutex); + + /* + * We collect delayed items before copying index keys from the subvolume + * to the log tree. However just after we collected them, they may have + * been flushed (all of them or just some of them), and therefore we + * could have copied them from the subvolume tree to the log tree. + * So find the first delayed item that was not yet logged (they are + * sorted by index number). + */ + list_for_each_entry(curr, delayed_ins_list, log_list) { + if (curr->index > inode->last_dir_index_offset) { + first = curr; + break; + } + } + + /* Empty list or all delayed items were already logged. */ + if (!first) + return 0; + + ins_data = kmalloc(max_batch_size * sizeof(u32) + + max_batch_size * sizeof(struct btrfs_key), GFP_NOFS); + if (!ins_data) + return -ENOMEM; + ins_sizes = (u32 *)ins_data; + batch.data_sizes = ins_sizes; + ins_keys = (struct btrfs_key *)(ins_data + max_batch_size * sizeof(u32)); + batch.keys = ins_keys; + + curr = first; + while (!list_entry_is_head(curr, delayed_ins_list, log_list)) { + const u32 curr_size = curr->data_len + sizeof(struct btrfs_item); + + if (curr_batch_size + curr_size > leaf_data_size || + batch.nr == max_batch_size) { + ret = insert_delayed_items_batch(trans, log, path, + &batch, first); + if (ret) + goto out; + batch_idx = 0; + batch.nr = 0; + batch.total_data_size = 0; + curr_batch_size = 0; + first = curr; + } + + ins_sizes[batch_idx] = curr->data_len; + ins_keys[batch_idx].objectid = ino; + ins_keys[batch_idx].type = BTRFS_DIR_INDEX_KEY; + ins_keys[batch_idx].offset = curr->index; + curr_batch_size += curr_size; + batch.total_data_size += curr->data_len; + batch.nr++; + batch_idx++; + curr = list_next_entry(curr, log_list); + } + + ASSERT(batch.nr >= 1); + ret = insert_delayed_items_batch(trans, log, path, &batch, first); + + curr = list_last_entry(delayed_ins_list, struct btrfs_delayed_item, + log_list); + inode->last_dir_index_offset = curr->index; +out: + kfree(ins_data); + + return ret; +} + +static int log_delayed_deletions_full(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_del_list, + struct btrfs_log_ctx *ctx) +{ + const u64 ino = btrfs_ino(inode); + const struct btrfs_delayed_item *curr; + + curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item, + log_list); + + while (!list_entry_is_head(curr, delayed_del_list, log_list)) { + u64 first_dir_index = curr->index; + u64 last_dir_index; + const struct btrfs_delayed_item *next; + int ret; + + /* + * Find a range of consecutive dir index items to delete. Like + * this we log a single dir range item spanning several contiguous + * dir items instead of logging one range item per dir index item. + */ + next = list_next_entry(curr, log_list); + while (!list_entry_is_head(next, delayed_del_list, log_list)) { + if (next->index != curr->index + 1) + break; + curr = next; + next = list_next_entry(next, log_list); + } + + last_dir_index = curr->index; + ASSERT(last_dir_index >= first_dir_index); + + ret = insert_dir_log_key(trans, inode->root->log_root, path, + ino, first_dir_index, last_dir_index); + if (ret) + return ret; + curr = list_next_entry(curr, log_list); + } + + return 0; +} + +static int batch_delete_dir_index_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_log_ctx *ctx, + const struct list_head *delayed_del_list, + const struct btrfs_delayed_item *first, + const struct btrfs_delayed_item **last_ret) +{ + const struct btrfs_delayed_item *next; + struct extent_buffer *leaf = path->nodes[0]; + const int last_slot = btrfs_header_nritems(leaf) - 1; + int slot = path->slots[0] + 1; + const u64 ino = btrfs_ino(inode); + + next = list_next_entry(first, log_list); + + while (slot < last_slot && + !list_entry_is_head(next, delayed_del_list, log_list)) { + struct btrfs_key key; + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != ino || + key.type != BTRFS_DIR_INDEX_KEY || + key.offset != next->index) + break; + + slot++; + *last_ret = next; + next = list_next_entry(next, log_list); + } + + return btrfs_del_items(trans, inode->root->log_root, path, + path->slots[0], slot - path->slots[0]); +} + +static int log_delayed_deletions_incremental(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_del_list, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *log = inode->root->log_root; + const struct btrfs_delayed_item *curr; + u64 last_range_start; + u64 last_range_end = 0; + struct btrfs_key key; + + key.objectid = btrfs_ino(inode); + key.type = BTRFS_DIR_INDEX_KEY; + curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item, + log_list); + + while (!list_entry_is_head(curr, delayed_del_list, log_list)) { + const struct btrfs_delayed_item *last = curr; + u64 first_dir_index = curr->index; + u64 last_dir_index; + bool deleted_items = false; + int ret; + + key.offset = curr->index; + ret = btrfs_search_slot(trans, log, &key, path, -1, 1); + if (ret < 0) { + return ret; + } else if (ret == 0) { + ret = batch_delete_dir_index_items(trans, inode, path, ctx, + delayed_del_list, curr, + &last); + if (ret) + return ret; + deleted_items = true; + } + + btrfs_release_path(path); + + /* + * If we deleted items from the leaf, it means we have a range + * item logging their range, so no need to add one or update an + * existing one. Otherwise we have to log a dir range item. + */ + if (deleted_items) + goto next_batch; + + last_dir_index = last->index; + ASSERT(last_dir_index >= first_dir_index); + /* + * If this range starts right after where the previous one ends, + * then we want to reuse the previous range item and change its + * end offset to the end of this range. This is just to minimize + * leaf space usage, by avoiding adding a new range item. + */ + if (last_range_end != 0 && first_dir_index == last_range_end + 1) + first_dir_index = last_range_start; + + ret = insert_dir_log_key(trans, log, path, key.objectid, + first_dir_index, last_dir_index); + if (ret) + return ret; + + last_range_start = first_dir_index; + last_range_end = last_dir_index; +next_batch: + curr = list_next_entry(last, log_list); + } + + return 0; +} + +static int log_delayed_deletion_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_del_list, + struct btrfs_log_ctx *ctx) +{ + /* + * We are deleting dir index items from the log tree or adding range + * items to it. + */ + lockdep_assert_held(&inode->log_mutex); + + if (list_empty(delayed_del_list)) + return 0; + + if (ctx->logged_before) + return log_delayed_deletions_incremental(trans, inode, path, + delayed_del_list, ctx); + + return log_delayed_deletions_full(trans, inode, path, delayed_del_list, + ctx); +} + +/* + * Similar logic as for log_new_dir_dentries(), but it iterates over the delayed + * items instead of the subvolume tree. + */ +static int log_new_delayed_dentries(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + const struct list_head *delayed_ins_list, + struct btrfs_log_ctx *ctx) +{ + const bool orig_log_new_dentries = ctx->log_new_dentries; + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_delayed_item *item; + int ret = 0; + + /* + * No need for the log mutex, plus to avoid potential deadlocks or + * lockdep annotations due to nesting of delayed inode mutexes and log + * mutexes. + */ + lockdep_assert_not_held(&inode->log_mutex); + + ASSERT(!ctx->logging_new_delayed_dentries); + ctx->logging_new_delayed_dentries = true; + + list_for_each_entry(item, delayed_ins_list, log_list) { + struct btrfs_dir_item *dir_item; + struct inode *di_inode; + struct btrfs_key key; + int log_mode = LOG_INODE_EXISTS; + + dir_item = (struct btrfs_dir_item *)item->data; + btrfs_disk_key_to_cpu(&key, &dir_item->location); + + if (key.type == BTRFS_ROOT_ITEM_KEY) + continue; + + di_inode = btrfs_iget(fs_info->sb, key.objectid, inode->root); + if (IS_ERR(di_inode)) { + ret = PTR_ERR(di_inode); + break; + } + + if (!need_log_inode(trans, BTRFS_I(di_inode))) { + btrfs_add_delayed_iput(di_inode); + continue; + } + + if (btrfs_stack_dir_type(dir_item) == BTRFS_FT_DIR) + log_mode = LOG_INODE_ALL; + + ctx->log_new_dentries = false; + ret = btrfs_log_inode(trans, BTRFS_I(di_inode), log_mode, ctx); + + if (!ret && ctx->log_new_dentries) + ret = log_new_dir_dentries(trans, BTRFS_I(di_inode), ctx); + + btrfs_add_delayed_iput(di_inode); + + if (ret) + break; + } + + ctx->log_new_dentries = orig_log_new_dentries; + ctx->logging_new_delayed_dentries = false; + + 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. @@ -5950,6 +6315,9 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, bool need_log_inode_item = true; bool xattrs_logged = false; bool inode_item_dropped = true; + bool full_dir_logging = false; + LIST_HEAD(delayed_ins_list); + LIST_HEAD(delayed_del_list); path = btrfs_alloc_path(); if (!path) @@ -5977,12 +6345,40 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, max_key.type = (u8)-1; max_key.offset = (u64)-1; + if (S_ISDIR(inode->vfs_inode.i_mode) && inode_only == LOG_INODE_ALL) + full_dir_logging = true; + /* - * 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. + * If we are logging a directory while we are logging dentries of the + * delayed items of some other inode, then we need to flush the delayed + * items of this directory and not log the delayed items directly. This + * is to prevent more than one level of recursion into btrfs_log_inode() + * by having something like this: + * + * $ mkdir -p a/b/c/d/e/f/g/h/... + * $ xfs_io -c "fsync" a + * + * Where all directories in the path did not exist before and are + * created in the current transaction. + * So in such a case we directly log the delayed items of the main + * directory ("a") without flushing them first, while for each of its + * subdirectories we flush their delayed items before logging them. + * This prevents a potential unbounded recursion like this: + * + * btrfs_log_inode() + * log_new_delayed_dentries() + * btrfs_log_inode() + * log_new_delayed_dentries() + * btrfs_log_inode() + * log_new_delayed_dentries() + * (...) + * + * We have thresholds for the maximum number of delayed items to have in + * memory, and once they are hit, the items are flushed asynchronously. + * However the limit is quite high, so lets prevent deep levels of + * recursion to happen by limitting the maximum depth to be 1. */ - if (S_ISDIR(inode->vfs_inode.i_mode)) { + if (full_dir_logging && ctx->logging_new_delayed_dentries) { ret = btrfs_commit_inode_delayed_items(trans, inode); if (ret) goto out; @@ -6020,9 +6416,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, * 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) { + if (full_dir_logging && inode->last_unlink_trans >= trans->transid) { btrfs_set_log_full_commit(trans); ret = BTRFS_LOG_FORCE_COMMIT; goto out_unlock; @@ -6092,6 +6486,16 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, if (ret) goto out_unlock; + /* + * If we are logging a directory in full mode, collect the delayed items + * before iterating the subvolume tree, so that we don't miss any new + * dir index items in case they get flushed while or right after we are + * iterating the subvolume tree. + */ + if (full_dir_logging && !ctx->logging_new_delayed_dentries) + btrfs_log_get_delayed_items(inode, &delayed_ins_list, + &delayed_del_list); + ret = copy_inode_items_to_log(trans, inode, &min_key, &max_key, path, dst_path, logged_isize, inode_only, ctx, @@ -6147,10 +6551,18 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, write_unlock(&em_tree->lock); } - if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) { + if (full_dir_logging) { ret = log_directory_changes(trans, inode, path, dst_path, ctx); if (ret) goto out_unlock; + ret = log_delayed_insertion_items(trans, inode, path, + &delayed_ins_list, ctx); + if (ret) + goto out_unlock; + ret = log_delayed_deletion_items(trans, inode, path, + &delayed_del_list, ctx); + if (ret) + goto out_unlock; } spin_lock(&inode->lock); @@ -6208,6 +6620,15 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, else ret = log_conflicting_inodes(trans, inode->root, ctx); + if (full_dir_logging && !ctx->logging_new_delayed_dentries) { + if (!ret) + ret = log_new_delayed_dentries(trans, inode, + &delayed_ins_list, ctx); + + btrfs_log_put_delayed_items(inode, &delayed_ins_list, + &delayed_del_list); + } + return ret; } diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h index 4e34fe4b7762..aed1e05e9879 100644 --- a/fs/btrfs/tree-log.h +++ b/fs/btrfs/tree-log.h @@ -20,6 +20,7 @@ struct btrfs_log_ctx { int log_transid; bool log_new_dentries; bool logging_new_name; + bool logging_new_delayed_dentries; /* Indicate if the inode being logged was logged before. */ bool logged_before; /* Tracks the last logged dir item/index key offset. */ @@ -40,6 +41,7 @@ static inline void btrfs_init_log_ctx(struct btrfs_log_ctx *ctx, ctx->log_transid = 0; ctx->log_new_dentries = false; ctx->logging_new_name = false; + ctx->logging_new_delayed_dentries = false; ctx->logged_before = false; ctx->inode = inode; INIT_LIST_HEAD(&ctx->list);