From patchwork Mon Aug 30 14:25:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 12465369 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 41778C432BE for ; Mon, 30 Aug 2021 14:25:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A31060F25 for ; Mon, 30 Aug 2021 14:25:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237368AbhH3O0p (ORCPT ); Mon, 30 Aug 2021 10:26:45 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:55950 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237220AbhH3O0n (ORCPT ); Mon, 30 Aug 2021 10:26:43 -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 D0DF8200C0; Mon, 30 Aug 2021 14:25:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1630333548; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=xsr7LY1mUCpXYjBcFhqAUYzYu8lMRAEivasf4ZTEGSY=; b=XBJadKhtZ4z8vIrZJwD7VjVcW8X5LgGRQTTwAiYdW9g2HN7P95BKgMCESUS60Er/pMoCf9 Ywnc4bLjHcVh996ca9BhQ998RLxT9avGWzBIAAMCnqalgDWWeMiiYa3IW4blsLsXYLIDjV P30G3LHshsmtZEt8g0222zsTuuAjPr0= 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 9E97713990; Mon, 30 Aug 2021 14:25:48 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap1.suse-dmz.suse.de with ESMTPSA id q8H7I2zqLGF4BQAAGKfGzw (envelope-from ); Mon, 30 Aug 2021 14:25:48 +0000 From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov Subject: [RESEND PATCH] btrfs: Refactor error handling in btrfs_zero_range Date: Mon, 30 Aug 2021 17:25:47 +0300 Message-Id: <20210830142547.889802-1-nborisov@suse.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The major complexity when it comes to error handling in btrfs_zero_range stems from the code executed under the 'reserve_space' label. Rather than it having an effect on the whole of btrfs_zero_range refactor it so that error handling specific to the functions called in this branch is contained only within the branch itself. This obviates the need for having the 'space_reserved' local flag since btrfs_free_reserved_data_space is called from the 2 error branches it's needed. Furthermore, this rids the code from the out label and enables converting most 'goto out' statements to simiple 'return ret' making the function easier to read. Signed-off-by: Nikolay Borisov --- I sent this patch some time ago but didn't get any replies so now I'm resending it again. fs/btrfs/file.c | 70 +++++++++++++++++++++++-------------------------- 1 file changed, 33 insertions(+), 37 deletions(-) -- 2.25.1 diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 7ff577005d0f..94f4353618d4 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3143,23 +3143,19 @@ static int btrfs_zero_range(struct inode *inode, { struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; struct extent_map *em; - struct extent_changeset *data_reserved = NULL; int ret; u64 alloc_hint = 0; const u64 sectorsize = btrfs_inode_sectorsize(BTRFS_I(inode)); u64 alloc_start = round_down(offset, sectorsize); u64 alloc_end = round_up(offset + len, sectorsize); u64 bytes_to_reserve = 0; - bool space_reserved = false; inode_dio_wait(inode); em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start, alloc_end - alloc_start); - if (IS_ERR(em)) { - ret = PTR_ERR(em); - goto out; - } + if (IS_ERR(em)) + return PTR_ERR(em); /* * Avoid hole punching and extent allocation for some cases. More cases @@ -3180,9 +3176,8 @@ static int btrfs_zero_range(struct inode *inode, * needed. */ free_extent_map(em); - ret = btrfs_fallocate_update_isize(inode, offset + len, - mode); - goto out; + return btrfs_fallocate_update_isize(inode, offset + len, + mode); } /* * Part of the range is already a prealloc extent, so operate @@ -3200,26 +3195,22 @@ static int btrfs_zero_range(struct inode *inode, BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) { em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start, sectorsize); - if (IS_ERR(em)) { - ret = PTR_ERR(em); - goto out; - } + if (IS_ERR(em)) + return PTR_ERR(em); if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { free_extent_map(em); - ret = btrfs_fallocate_update_isize(inode, offset + len, - mode); - goto out; + return btrfs_fallocate_update_isize(inode, + offset + len, mode); } if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) { free_extent_map(em); ret = btrfs_truncate_block(BTRFS_I(inode), offset, len, 0); - if (!ret) - ret = btrfs_fallocate_update_isize(inode, - offset + len, - mode); - return ret; + if (ret) + return ret; + return btrfs_fallocate_update_isize(inode, + offset + len, mode); } free_extent_map(em); alloc_start = round_down(offset, sectorsize); @@ -3240,14 +3231,14 @@ static int btrfs_zero_range(struct inode *inode, ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode), offset); if (ret < 0) - goto out; + return ret; if (ret == RANGE_BOUNDARY_HOLE) { alloc_start = round_down(offset, sectorsize); ret = 0; } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) { ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0); if (ret) - goto out; + return ret; } else { ret = 0; } @@ -3257,7 +3248,7 @@ static int btrfs_zero_range(struct inode *inode, ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode), offset + len); if (ret < 0) - goto out; + return ret; if (ret == RANGE_BOUNDARY_HOLE) { alloc_end = round_up(offset + len, sectorsize); ret = 0; @@ -3265,7 +3256,7 @@ static int btrfs_zero_range(struct inode *inode, ret = btrfs_truncate_block(BTRFS_I(inode), offset + len, 0, 1); if (ret) - goto out; + return ret; } else { ret = 0; } @@ -3273,6 +3264,7 @@ static int btrfs_zero_range(struct inode *inode, reserve_space: if (alloc_start < alloc_end) { + struct extent_changeset *data_reserved = NULL; struct extent_state *cached_state = NULL; const u64 lockstart = alloc_start; const u64 lockend = alloc_end - 1; @@ -3281,18 +3273,27 @@ static int btrfs_zero_range(struct inode *inode, ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), bytes_to_reserve); if (ret < 0) - goto out; - space_reserved = true; + return ret; ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend, &cached_state); - if (ret) - goto out; + if (ret) { + btrfs_free_reserved_data_space(BTRFS_I(inode), + data_reserved, + alloc_start, + bytes_to_reserve); + return ret; + } ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved, alloc_start, bytes_to_reserve); if (ret) { + btrfs_free_reserved_data_space(BTRFS_I(inode), + data_reserved, + alloc_start, + bytes_to_reserve); unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, &cached_state); - goto out; + extent_changeset_free(data_reserved); + return ret; } ret = btrfs_prealloc_file_range(inode, mode, alloc_start, alloc_end - alloc_start, @@ -3302,16 +3303,11 @@ static int btrfs_zero_range(struct inode *inode, lockend, &cached_state); /* btrfs_prealloc_file_range releases reserved space on error */ if (ret) { - space_reserved = false; - goto out; + extent_changeset_free(data_reserved); + return ret; } } ret = btrfs_fallocate_update_isize(inode, offset + len, mode); - out: - if (ret && space_reserved) - btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved, - alloc_start, bytes_to_reserve); - extent_changeset_free(data_reserved); return ret; }