From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1153E13E897; Thu, 11 Apr 2024 10:17:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712830650; cv=none; b=EEMHW5CgmDT5Iixa3vHUdQAMEkol5cfZTFB5NA8GzjB7TkSIFw7CUR5rVhiim3/wijqEChQoQyIgRDY8adHM6FNw1biqGoXd/kQg8tUaQWFH1ppCoseEV+2w39JDe7UEK1GzaF8kPosm/qfKbu75IKv4XlEH5seTOn1Jx6fD78w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712830650; c=relaxed/simple; bh=NeaZaGHnxfD28dAQ16+ER401emNDcKwCNTWsCxVPrWA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tb2Kbr1dn/CxCNNN/biT8X98Uf677hfXy2amPojzUGGy83yxMyFatkp3TPqSQcTa1oH3U/vmTuUUZXgom/nYleMDtq836j37fzVnJaNP8nMH3Fzp1G9qBbWBFtnTAwwfS1+r+Dc7Bogc5r1kH6PAPHoPPwrzZuXQEoDYl6QTsr0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=G3D5BoQh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="G3D5BoQh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E3F4C433C7; Thu, 11 Apr 2024 10:17:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712830649; bh=NeaZaGHnxfD28dAQ16+ER401emNDcKwCNTWsCxVPrWA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G3D5BoQhJeRuItbBSbgETnFb59ZGR5w8AtrW81HR7k7r62HAPER9hrNH8cpvXGDGF hYt3pyRP/4sCA8leGctETzZ55IErcZ/MfM6DKEUgXDA1A0mNdfY+WbGjqS1/bu9XX4 XhV20WrvbQ0H0YDKwoCtKYQmgxYFqzPIUHV84dzA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, yangerkun , Baokun Li , Jan Kara , Ojaswin Mujoo , Theodore Tso , Sasha Levin Subject: [PATCH 5.4 022/215] ext4: correct best extent lstart adjustment logic Date: Thu, 11 Apr 2024 11:53:51 +0200 Message-ID: <20240411095425.551449165@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095424.875421572@linuxfoundation.org> References: <20240411095424.875421572@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li [ Upstream commit 4fbf8bc733d14bceb16dda46a3f5e19c6a9621c5 ] When yangerkun review commit 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()"), it was found that the best extent did not completely cover the original request after adjusting the best extent lstart in ext4_mb_new_inode_pa() as follows: original request: 2/10(8) normalized request: 0/64(64) best extent: 0/9(9) When we check if best ex can be kept at start of goal, ac_o_ex.fe_logical is 2 less than the adjusted best extent logical end 9, so we think the adjustment is done. But obviously 0/9(9) doesn't cover 2/10(8), so we should determine here if the original request logical end is less than or equal to the adjusted best extent logical end. In addition, add a comment stating when adjusted best_ex will not cover the original request, and remove the duplicate assertion because adjusting lstart makes no change to b_ex.fe_len. Link: https://lore.kernel.org/r/3630fa7f-b432-7afd-5f79-781bc3b2c5ea@huawei.com Fixes: 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()") Cc: Signed-off-by: yangerkun Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Ojaswin Mujoo Link: https://lore.kernel.org/r/20240201141845.1879253-1-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/mballoc.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index e823731110e3e..b2e7b1907d410 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3692,10 +3692,16 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) .fe_len = ac->ac_g_ex.fe_len, }; loff_t orig_goal_end = extent_logical_end(sbi, &ex); + loff_t o_ex_end = extent_logical_end(sbi, &ac->ac_o_ex); - /* we can't allocate as much as normalizer wants. - * so, found space must get proper lstart - * to cover original request */ + /* + * We can't allocate as much as normalizer wants, so we try + * to get proper lstart to cover the original request, except + * when the goal doesn't cover the original request as below: + * + * orig_ex:2045/2055(10), isize:8417280 -> normalized:0/2048 + * best_ex:0/200(200) -> adjusted: 1848/2048(200) + */ BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical); BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len); @@ -3707,7 +3713,7 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) * 1. Check if best ex can be kept at end of goal and still * cover original start * 2. Else, check if best ex can be kept at start of goal and - * still cover original start + * still cover original end * 3. Else, keep the best ex at start of original request. */ ex.fe_len = ac->ac_b_ex.fe_len; @@ -3717,7 +3723,7 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) goto adjust_bex; ex.fe_logical = ac->ac_g_ex.fe_logical; - if (ac->ac_o_ex.fe_logical < extent_logical_end(sbi, &ex)) + if (o_ex_end <= extent_logical_end(sbi, &ex)) goto adjust_bex; ex.fe_logical = ac->ac_o_ex.fe_logical; @@ -3725,7 +3731,6 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) ac->ac_b_ex.fe_logical = ex.fe_logical; BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); - BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); BUG_ON(extent_logical_end(sbi, &ex) > orig_goal_end); } -- 2.43.0