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 C16DF1AC884; Fri, 1 Nov 2024 15:12:59 +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=1730473979; cv=none; b=a6aeOVVkIKWLT///ohXil00O049rMj1HFy0Sry5S/ryveK4fc8olpCpXTIZACNypvM6XqY8jglt/WGKLiTMDuYVsIMnJDmf+9HTRTbLUWOLYWrcIJaI3evHIcJA+NnTM2fIRw62NZXoB6/p03PypXR41GQabZDiYqy5ArTP8nKo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730473979; c=relaxed/simple; bh=ekg2hMYbznCWaygXXUdGZ3n+I2d1nv9q5j+6mo/Z790=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Fm+GgRcIVFVqNfMaR5azITrWh75RVse95wWVlS2YXFjBOWQHcdNC+0jxm2vRMoNlfNcRQEWrqLdjfRgkRMJQFbJgs2Q6kOQzzAGDFcyt18JTIhbD4lI+GBXysDgXAAKchDuuzdoCmW68Q+3x8gwBmvZWl2fR24Vpf/r9OI0S/zE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LXjwbnlx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LXjwbnlx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F3BDC4CECD; Fri, 1 Nov 2024 15:12:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730473979; bh=ekg2hMYbznCWaygXXUdGZ3n+I2d1nv9q5j+6mo/Z790=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LXjwbnlxiTg55GSnTO31Ut03qEys8JTLEYgutdQfLcHxxyuP7PO2gsr6scoeuZdPx TDa/kIFuLE3jEQdz32QVirg3VkJmK5iAHtoeylhbaqsmoeOvg0kzKrlLTEIWLeUJls 4D+/+Qj9NQxYu6LE5Nb3g6iUd/nCBoWspM1y2olcEk0FValyyE3RUgPgjkfm+4jJkx G8cOsnzk6fqRAjO/AvjNVnwYxNVBnFAkqePhIUiRjJzgGrHAhJdYQx2fhqBZ6wXyoi vgNJMRA4PMmj80oq7QR7R++/pGnva1GcfHEBh6MnJpVKBS4EDMf2B4w8IzmCi1RvcP XIlKkeRGxWBYA== Date: Fri, 1 Nov 2024 08:12:58 -0700 From: "Darrick J. Wong" To: "Ritesh Harjani (IBM)" Cc: linux-ext4@vger.kernel.org, Theodore Ts'o , Jan Kara , Christoph Hellwig , John Garry , Ojaswin Mujoo , Dave Chinner , linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v4 1/4] ext4: Add statx support for atomic writes Message-ID: <20241101151258.GG2386201@frogsfrogsfrogs> References: <0517cef1682fc1f344343c494ac769b963f94199.1730437365.git.ritesh.list@gmail.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0517cef1682fc1f344343c494ac769b963f94199.1730437365.git.ritesh.list@gmail.com> On Fri, Nov 01, 2024 at 12:20:51PM +0530, Ritesh Harjani (IBM) wrote: > This patch adds base support for atomic writes via statx getattr. > On bs < ps systems, we can create FS with say bs of 16k. That means > both atomic write min and max unit can be set to 16k for supporting > atomic writes. > > Co-developed-by: Ojaswin Mujoo > Signed-off-by: Ojaswin Mujoo > Signed-off-by: Ritesh Harjani (IBM) Looks good to me, Reviewed-by: Darrick J. Wong --D > --- > fs/ext4/ext4.h | 10 ++++++++++ > fs/ext4/inode.c | 12 ++++++++++++ > fs/ext4/super.c | 31 +++++++++++++++++++++++++++++++ > 3 files changed, 53 insertions(+) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 44b0d418143c..494d443e9fc9 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1729,6 +1729,10 @@ struct ext4_sb_info { > */ > struct work_struct s_sb_upd_work; > > + /* Atomic write unit values in bytes */ > + unsigned int s_awu_min; > + unsigned int s_awu_max; > + > /* Ext4 fast commit sub transaction ID */ > atomic_t s_fc_subtid; > > @@ -3855,6 +3859,12 @@ static inline int ext4_buffer_uptodate(struct buffer_head *bh) > return buffer_uptodate(bh); > } > > +static inline bool ext4_inode_can_atomic_write(struct inode *inode) > +{ > + > + return S_ISREG(inode->i_mode) && EXT4_SB(inode->i_sb)->s_awu_min > 0; > +} > + > extern int ext4_block_write_begin(handle_t *handle, struct folio *folio, > loff_t pos, unsigned len, > get_block_t *get_block); > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 54bdd4884fe6..3e827cfa762e 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -5578,6 +5578,18 @@ int ext4_getattr(struct mnt_idmap *idmap, const struct path *path, > } > } > > + if ((request_mask & STATX_WRITE_ATOMIC) && S_ISREG(inode->i_mode)) { > + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); > + unsigned int awu_min = 0, awu_max = 0; > + > + if (ext4_inode_can_atomic_write(inode)) { > + awu_min = sbi->s_awu_min; > + awu_max = sbi->s_awu_max; > + } > + > + generic_fill_statx_atomic_writes(stat, awu_min, awu_max); > + } > + > flags = ei->i_flags & EXT4_FL_USER_VISIBLE; > if (flags & EXT4_APPEND_FL) > stat->attributes |= STATX_ATTR_APPEND; > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 16a4ce704460..ebe1660bd840 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -4425,6 +4425,36 @@ static int ext4_handle_clustersize(struct super_block *sb) > return 0; > } > > +/* > + * ext4_atomic_write_init: Initializes filesystem min & max atomic write units. > + * @sb: super block > + * TODO: Later add support for bigalloc > + */ > +static void ext4_atomic_write_init(struct super_block *sb) > +{ > + struct ext4_sb_info *sbi = EXT4_SB(sb); > + struct block_device *bdev = sb->s_bdev; > + > + if (!bdev_can_atomic_write(bdev)) > + return; > + > + if (!ext4_has_feature_extents(sb)) > + return; > + > + sbi->s_awu_min = max(sb->s_blocksize, > + bdev_atomic_write_unit_min_bytes(bdev)); > + sbi->s_awu_max = min(sb->s_blocksize, > + bdev_atomic_write_unit_max_bytes(bdev)); > + if (sbi->s_awu_min && sbi->s_awu_max && > + sbi->s_awu_min <= sbi->s_awu_max) { > + ext4_msg(sb, KERN_NOTICE, "Supports (experimental) DIO atomic writes awu_min: %u, awu_max: %u", > + sbi->s_awu_min, sbi->s_awu_max); > + } else { > + sbi->s_awu_min = 0; > + sbi->s_awu_max = 0; > + } > +} > + > static void ext4_fast_commit_init(struct super_block *sb) > { > struct ext4_sb_info *sbi = EXT4_SB(sb); > @@ -5336,6 +5366,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) > > spin_lock_init(&sbi->s_bdev_wb_lock); > > + ext4_atomic_write_init(sb); > ext4_fast_commit_init(sb); > > sb->s_root = NULL; > -- > 2.46.0 > >