From patchwork Thu Mar 20 05:34:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 14023445 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 89CAD155753 for ; Thu, 20 Mar 2025 05:34:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742448880; cv=none; b=h/yxZIeoyr8MqnIIPVzXE5VWFoprVzpKoLYAEEdH8fX7Vy/Oq4itbg3S8ZvDKDGyMXOdXEXRZ01HFFda4cfhe7zH/Z5iIhspF7BkwfjVSzeYJ3xURTq/1fil6rzxjKWHx7sAcYKK5w5i2xJ0utQ6x44tpiBd4ynY3f2pmsPz9Lw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742448880; c=relaxed/simple; bh=FV5gvgPNKj7DXmV+iMabSXscV/E/uWadaYGSKvytIPA=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cqIZt7+IBoS6wyNfTkeEuaAJFHiGw49dV/jy+0KXvC19LqawVqONVqm0+8qanE5C8adU3HRL3DMB1N0c5lCoyWvzfAw4ds/czcdMjvyC8rS5WK66Xi1RftDbWmQPJX4c8Sgp5mAB/XnMMl/tTu2UkTq+7c26DoWiBL3F9dA5I+I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=Tvh0nkA0; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b=Tvh0nkA0; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="Tvh0nkA0"; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="Tvh0nkA0" Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 965861F7C3 for ; Thu, 20 Mar 2025 05:34:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1742448876; 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=W0bKQqV+MkkHPe7DZIpBz0LFXLdD07HsBuq459cApq8=; b=Tvh0nkA0bG+ZHxtdmUbO9xpF7Xscwavom+HMjP+p0X/c3Mww5FfSsiGjzl/OjO9Ym86DeS YOmsy+DbwV/o5uD5XDa2K1Ej/tatYGk+AfqBdISmro1szcU0YeuRjovKxY3t6gVkTbzQsJ hCzhn4kg17STgFrnsudfONyIMmb9X6w= Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1742448876; 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=W0bKQqV+MkkHPe7DZIpBz0LFXLdD07HsBuq459cApq8=; b=Tvh0nkA0bG+ZHxtdmUbO9xpF7Xscwavom+HMjP+p0X/c3Mww5FfSsiGjzl/OjO9Ym86DeS YOmsy+DbwV/o5uD5XDa2K1Ej/tatYGk+AfqBdISmro1szcU0YeuRjovKxY3t6gVkTbzQsJ hCzhn4kg17STgFrnsudfONyIMmb9X6w= Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 90DB7138A5 for ; Thu, 20 Mar 2025 05:34:35 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id qLSnD+uo22fcMQAAD6G6ig (envelope-from ) for ; Thu, 20 Mar 2025 05:34:35 +0000 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH 3/4] btrfs: extract the space reservation code from btrfs_buffered_write() Date: Thu, 20 Mar 2025 16:04:10 +1030 Message-ID: <522bfb923444f08b2c68c51a05cb5ca8b3ac7a77.1742443383.git.wqu@suse.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Score: -2.80 X-Spamd-Result: default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; ARC_NA(0.00)[]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:mid,suse.com:email]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[linux-btrfs@vger.kernel.org]; RCVD_TLS_ALL(0.00)[] X-Spam-Flag: NO X-Spam-Level: Inside the main loop of btrfs_buffered_write(), we have a complex data and metadata space reservation code, which tries to reserve space for a COW write, if failed then fallback to check if we can do a NOCOW write. Extract that part of code into a dedicated helper, reserve_space(), to make the main loop a little easier to read. Signed-off-by: Qu Wenruo Reviewed-by: Johannes Thumshirn Reviewed-by: Filipe Manana --- fs/btrfs/file.c | 108 ++++++++++++++++++++++++++++-------------------- 1 file changed, 63 insertions(+), 45 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index f68846c14ed5..99580ef906a6 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1095,6 +1095,64 @@ static void release_space(struct btrfs_inode *inode, } } +/* + * Reserve data and metadata space for the this buffered write range. + * + * Return >0 for the number of bytes reserved, which is always block aligned. + * Return <0 for error. + */ +static ssize_t reserve_space(struct btrfs_inode *inode, + struct extent_changeset **data_reserved, + u64 start, size_t *len, bool nowait, + bool *only_release_metadata) +{ + const struct btrfs_fs_info *fs_info = inode->root->fs_info; + unsigned int block_offset = start & (fs_info->sectorsize - 1); + size_t reserve_bytes; + int ret; + + ret = btrfs_check_data_free_space(inode, data_reserved, start, *len, + nowait); + if (ret < 0) { + int can_nocow; + + if (nowait && (ret == -ENOSPC || ret == -EAGAIN)) + return -EAGAIN; + + /* + * If we don't have to COW at the offset, reserve + * metadata only. write_bytes may get smaller than + * requested here. + */ + can_nocow = btrfs_check_nocow_lock(inode, start, len, nowait); + if (can_nocow < 0) + ret = can_nocow; + if (can_nocow > 0) + ret = 0; + if (ret) + return ret; + *only_release_metadata = true; + } + + reserve_bytes = round_up(*len + block_offset, + fs_info->sectorsize); + WARN_ON(reserve_bytes == 0); + ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes, + reserve_bytes, nowait); + if (ret) { + if (!*only_release_metadata) + btrfs_free_reserved_data_space(inode, + *data_reserved, start, *len); + else + btrfs_check_nocow_unlock(inode); + + if (nowait && ret == -ENOSPC) + ret = -EAGAIN; + return ret; + } + return reserve_bytes; +} + ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) { struct file *file = iocb->ki_filp; @@ -1160,52 +1218,12 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) sector_offset = pos & (fs_info->sectorsize - 1); extent_changeset_release(data_reserved); - ret = btrfs_check_data_free_space(BTRFS_I(inode), - &data_reserved, pos, - write_bytes, nowait); - if (ret < 0) { - int can_nocow; - - if (nowait && (ret == -ENOSPC || ret == -EAGAIN)) { - ret = -EAGAIN; - break; - } - - /* - * If we don't have to COW at the offset, reserve - * metadata only. write_bytes may get smaller than - * requested here. - */ - can_nocow = btrfs_check_nocow_lock(BTRFS_I(inode), pos, - &write_bytes, nowait); - if (can_nocow < 0) - ret = can_nocow; - if (can_nocow > 0) - ret = 0; - if (ret) - break; - only_release_metadata = true; - } - - reserve_bytes = round_up(write_bytes + sector_offset, - fs_info->sectorsize); - WARN_ON(reserve_bytes == 0); - ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), - reserve_bytes, - reserve_bytes, nowait); - if (ret) { - if (!only_release_metadata) - btrfs_free_reserved_data_space(BTRFS_I(inode), - data_reserved, pos, - write_bytes); - else - btrfs_check_nocow_unlock(BTRFS_I(inode)); - - if (nowait && ret == -ENOSPC) - ret = -EAGAIN; + ret = reserve_space(BTRFS_I(inode), &data_reserved, pos, + &write_bytes, nowait, + &only_release_metadata); + if (ret < 0) break; - } - + reserve_bytes = ret; release_bytes = reserve_bytes; again: ret = balance_dirty_pages_ratelimited_flags(inode->i_mapping, bdp_flags);