From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E40EC432BE for ; Fri, 6 Aug 2021 08:12:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 011D660238 for ; Fri, 6 Aug 2021 08:12:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243438AbhHFINM (ORCPT ); Fri, 6 Aug 2021 04:13:12 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:41124 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243428AbhHFINL (ORCPT ); Fri, 6 Aug 2021 04:13:11 -0400 Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 61EF120264 for ; Fri, 6 Aug 2021 08:12:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1628237575; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wPrEJ/Xuq6q8WDFh0+63GD9vtBTxqY6/Nd3TzLQQDms=; b=AIzCYNIhxPkxUQeisa78WsBCM0T7JTfbb8hbBjMogt/WbrjTAvMjuz2wjvjcyv5Rnd15dF hQLRXrY9Wbv9HMJegaqkzKYSSfMYWhIVj052JlaPA5MMsxwrXIUo56vuHSna7S1sNYudyu 0jQuAhdZrQqxHwG7u5/28PoIpvU/HQ8= Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap1.suse-dmz.suse.de (Postfix) with ESMTPS id 9D4ED1399D for ; Fri, 6 Aug 2021 08:12:54 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap1.suse-dmz.suse.de with ESMTPSA id eKR7FwbvDGF6IQAAGKfGzw (envelope-from ) for ; Fri, 06 Aug 2021 08:12:54 +0000 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v5 07/11] btrfs: defrag: introduce a helper to defrag a range Date: Fri, 6 Aug 2021 16:12:38 +0800 Message-Id: <20210806081242.257996-8-wqu@suse.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210806081242.257996-1-wqu@suse.com> References: <20210806081242.257996-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org A new helper, defrag_one_range(), is introduced to defrag one range. This function will mostly prepare the needed pages and extent status for defrag_one_locked_target(). As we can only have a consistent view of extent map with page and extent bits locked, we need to re-check the range passed in to get a real target list for defrag_one_locked_target(). Since defrag_collect_targets() will call defrag_lookup_extent() and lock extent range, we also need to teach those two functions to skip extent lock. Thus new parameter, @locked, is introruced to skip extent lock if the caller has already locked the range. Signed-off-by: Qu Wenruo --- fs/btrfs/ioctl.c | 105 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 95 insertions(+), 10 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index a21c4c09269a..2f7196f9bd65 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1081,7 +1081,8 @@ static int find_new_extents(struct btrfs_root *root, return -ENOENT; } -static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start) +static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start, + bool locked) { struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; @@ -1101,10 +1102,12 @@ static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start) u64 end = start + sectorsize - 1; /* get the big lock and read metadata off disk */ - lock_extent_bits(io_tree, start, end, &cached); + if (!locked) + lock_extent_bits(io_tree, start, end, &cached); em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, sectorsize); - unlock_extent_cached(io_tree, start, end, &cached); + if (!locked) + unlock_extent_cached(io_tree, start, end, &cached); if (IS_ERR(em)) return NULL; @@ -1113,7 +1116,8 @@ static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start) return em; } -static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em) +static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em, + bool locked) { struct extent_map *next; bool ret = true; @@ -1122,7 +1126,7 @@ static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em) if (em->start + em->len >= i_size_read(inode)) return false; - next = defrag_lookup_extent(inode, em->start + em->len); + next = defrag_lookup_extent(inode, em->start + em->len, locked); if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE) ret = false; else if ((em->block_start + em->block_len == next->block_start) && @@ -1151,7 +1155,7 @@ static int should_defrag_range(struct inode *inode, u64 start, u32 thresh, *skip = 0; - em = defrag_lookup_extent(inode, start); + em = defrag_lookup_extent(inode, start, false); if (!em) return 0; @@ -1164,7 +1168,7 @@ static int should_defrag_range(struct inode *inode, u64 start, u32 thresh, if (!*defrag_end) prev_mergeable = false; - next_mergeable = defrag_check_next_extent(inode, em); + next_mergeable = defrag_check_next_extent(inode, em, false); /* * we hit a real extent, if it is big or the next extent is not a * real extent, don't bother defragging it @@ -1445,12 +1449,13 @@ struct defrag_target_range { * @do_compress: Whether the defrag is doing compression * If true, @extent_thresh will be ignored and all regular * file extents meeting @newer_than will be targets. + * @locked: If the range has already hold extent lock * @target_list: The list of targets file extents */ static int defrag_collect_targets(struct btrfs_inode *inode, u64 start, u64 len, u32 extent_thresh, u64 newer_than, bool do_compress, - struct list_head *target_list) + bool locked, struct list_head *target_list) { u64 cur = start; int ret = 0; @@ -1461,7 +1466,7 @@ static int defrag_collect_targets(struct btrfs_inode *inode, bool next_mergeable = true; u64 range_len; - em = defrag_lookup_extent(&inode->vfs_inode, cur); + em = defrag_lookup_extent(&inode->vfs_inode, cur, locked); if (!em) break; @@ -1485,7 +1490,8 @@ static int defrag_collect_targets(struct btrfs_inode *inode, if (em->len >= extent_thresh) goto next; - next_mergeable = defrag_check_next_extent(&inode->vfs_inode, em); + next_mergeable = defrag_check_next_extent(&inode->vfs_inode, em, + locked); if (!next_mergeable) { struct defrag_target_range *last; @@ -1603,6 +1609,85 @@ static int defrag_one_locked_target(struct btrfs_inode *inode, return ret; } +static int defrag_one_range(struct btrfs_inode *inode, + u64 start, u32 len, + u32 extent_thresh, u64 newer_than, + bool do_compress) +{ + struct extent_state *cached_state = NULL; + struct defrag_target_range *entry; + struct defrag_target_range *tmp; + LIST_HEAD(target_list); + struct page **pages; + const u32 sectorsize = inode->root->fs_info->sectorsize; + unsigned long last_index = (start + len - 1) >> PAGE_SHIFT; + unsigned long start_index = start >> PAGE_SHIFT; + unsigned int nr_pages = last_index - start_index + 1; + int ret = 0; + int i; + + ASSERT(nr_pages <= CLUSTER_SIZE / PAGE_SIZE); + ASSERT(IS_ALIGNED(start, sectorsize) && IS_ALIGNED(len, sectorsize)); + + pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); + if (!pages) + return -ENOMEM; + + /* Prepare all pages */ + for (i = 0; i < nr_pages; i++) { + pages[i] = defrag_prepare_one_page(inode, start_index + i); + if (IS_ERR(pages[i])) { + ret = PTR_ERR(pages[i]); + pages[i] = NULL; + goto free_pages; + } + } + for (i = 0; i < nr_pages; i++) + wait_on_page_writeback(pages[i]); + + /* Also lock the pages range */ + lock_extent_bits(&inode->io_tree, start_index << PAGE_SHIFT, + (last_index << PAGE_SHIFT) + PAGE_SIZE - 1, + &cached_state); + /* + * Now we have a consistent view about the extent map, re-check + * which range really needs to be defragged. + * + * And this time we have extent locked already, pass @locked = true + * so that we won't re-lock the extent range and cause deadlock. + */ + ret = defrag_collect_targets(inode, start, len, extent_thresh, + newer_than, do_compress, true, + &target_list); + if (ret < 0) + goto unlock_extent; + + list_for_each_entry(entry, &target_list, list) { + ret = defrag_one_locked_target(inode, entry, pages, nr_pages, + &cached_state); + if (ret < 0) + break; + } + + list_for_each_entry_safe(entry, tmp, &target_list, list) { + list_del_init(&entry->list); + kfree(entry); + } +unlock_extent: + unlock_extent_cached(&inode->io_tree, start_index << PAGE_SHIFT, + (last_index << PAGE_SHIFT) + PAGE_SIZE - 1, + &cached_state); +free_pages: + for (i = 0; i < nr_pages; i++) { + if (pages[i]) { + unlock_page(pages[i]); + put_page(pages[i]); + } + } + kfree(pages); + return ret; +} + /* * Btrfs entrace for defrag. * -- 2.32.0