From nobody Mon Feb 9 16:33:16 2026 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 3AA8F38759A; Tue, 3 Feb 2026 06:30:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770100226; cv=none; b=X2TjtdL1uPrzb0vjs4cR2ItOfNleDMNbuVgkF0o6gYEYuJb2yTsGAg7syvu+kSFFXTAJVpTcr9ORmzwswp+u87v8LGX2YugfAPW+wTGZ5LikydMQNekGwREWOXoBpLo8viaEA74h/NSMtPItdNQA+xIrMzAIqBIZMmTnEUhsjds= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770100226; c=relaxed/simple; bh=7aGjj2yEAzOMByCYB7Wj1LVCh4ag9n3hHscskJsSD24=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=syZ8TkxvAX1tLEOYn7inXTAF1Nz3zhC24MBGN+ZJYw/fokIRnsTtMLf6foR3K3zm9I/DKsKrRCK+t062sWrYu+N8VImYzg8sQyzUjCc4gh4LJuzQUKzxLBk37BJax8PcuP+qdrh8tPJZprqEnQpBoutVsRiyqu0E+z3sGqWuLSw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.177]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4f4trL1M8CzKHMd3; Tue, 3 Feb 2026 14:29:54 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 808A74058C; Tue, 3 Feb 2026 14:30:15 +0800 (CST) Received: from huaweicloud.com (unknown [10.50.85.155]) by APP4 (Coremail) with SMTP id gCh0CgAHaPjnlYFpiadbGA--.27803S26; Tue, 03 Feb 2026 14:30:15 +0800 (CST) From: Zhang Yi To: linux-ext4@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, ojaswin@linux.ibm.com, ritesh.list@gmail.com, hch@infradead.org, djwong@kernel.org, yi.zhang@huawei.com, yi.zhang@huaweicloud.com, yizhang089@gmail.com, libaokun1@huawei.com, yangerkun@huawei.com, yukuai@fnnas.com Subject: [PATCH -next v2 22/22] ext4: introduce a mount option for iomap buffered I/O path Date: Tue, 3 Feb 2026 14:25:22 +0800 Message-ID: <20260203062523.3869120-23-yi.zhang@huawei.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260203062523.3869120-1-yi.zhang@huawei.com> References: <20260203062523.3869120-1-yi.zhang@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgAHaPjnlYFpiadbGA--.27803S26 X-Coremail-Antispam: 1UD129KBjvJXoWxAFWfCF13Gw1fGrWkXF4Dtwb_yoW5AFykpr 909FyrGw1DXr9Y9w48Cr4rJr1Yy3Z0ka1UurZ0grsrWFZrAryxXFyfKF1rCF4aqrW8X34I qF1rWw17WF43CrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUHSb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVWxJr0_GcWl84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAF wI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2 WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkE bVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjsIEF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI 8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14v26r1q6r43MxAIw28IcxkI7VAKI48JMxAI w28IcVAKzI0EY4vE52x082I5MxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI 0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y 0x0EwIxGrwCI42IY6xIIjxv20xvE14v26ryj6F1UMIIF0xvE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWx JwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7IU1-zst UUUUU== Sender: yi.zhang@huaweicloud.com X-CM-SenderInfo: d1lo6xhdqjqx5xdzvxpfor3voofrz/ Content-Type: text/plain; charset="utf-8" Since the iomap buffered I/O path does not yet support all existing features, it cannot be used by default. Introduce 'buffered_iomap' and 'nobuffered_iomap' mount options to enable and disable the iomap buffered I/O path for regular files. Signed-off-by: Zhang Yi --- fs/ext4/ext4.h | 1 + fs/ext4/inode.c | 2 ++ fs/ext4/super.c | 7 +++++++ 3 files changed, 10 insertions(+) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 259c6e780e65..4e209c14dab9 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1288,6 +1288,7 @@ struct ext4_inode_info { * scanning in mballoc */ #define EXT4_MOUNT2_ABORT 0x00000100 /* Abort filesystem */ +#define EXT4_MOUNT2_BUFFERED_IOMAP 0x00000200 /* Use iomap for buffered I/= O */ =20 #define clear_opt(sb, opt) EXT4_SB(sb)->s_mount_opt &=3D \ ~EXT4_MOUNT_##opt diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index bbdd0bb3bc8b..a3d7c98309bb 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5743,6 +5743,8 @@ void ext4_enable_buffered_iomap(struct inode *inode) { struct super_block *sb =3D inode->i_sb; =20 + if (!test_opt2(sb, BUFFERED_IOMAP)) + return; if (!S_ISREG(inode->i_mode)) return; if (ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE)) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 4bb77703ffe1..d967792c7cb1 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1701,6 +1701,7 @@ enum { Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable, Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache, Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan, + Opt_buffered_iomap, Opt_nobuffered_iomap, Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type, #ifdef CONFIG_EXT4_DEBUG Opt_fc_debug_max_replay, Opt_fc_debug_force @@ -1839,6 +1840,8 @@ static const struct fs_parameter_spec ext4_param_spec= s[] =3D { fsparam_flag ("no_prefetch_block_bitmaps", Opt_no_prefetch_block_bitmaps), fsparam_s32 ("mb_optimize_scan", Opt_mb_optimize_scan), + fsparam_flag ("buffered_iomap", Opt_buffered_iomap), + fsparam_flag ("nobuffered_iomap", Opt_nobuffered_iomap), fsparam_string ("check", Opt_removed), /* mount option from ext2/3 */ fsparam_flag ("nocheck", Opt_removed), /* mount option from ext2/3 */ fsparam_flag ("reservation", Opt_removed), /* mount option from ext2/3 */ @@ -1932,6 +1935,10 @@ static const struct mount_opts { {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET}, {Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS, MOPT_SET}, + {Opt_buffered_iomap, EXT4_MOUNT2_BUFFERED_IOMAP, + MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY}, + {Opt_nobuffered_iomap, EXT4_MOUNT2_BUFFERED_IOMAP, + MOPT_CLEAR | MOPT_2 | MOPT_EXT4_ONLY}, #ifdef CONFIG_EXT4_DEBUG {Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT, MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY}, --=20 2.52.0