From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9B2C51E0DE8; Wed, 24 Jun 2026 18:03:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782324209; cv=none; b=pxGOQ9M9vF0UNcHS78dZFlQz+pYmTLZOAIYbHkb6KkMYDKVmDZJdTkg5hXtOkO1ey+Oibx09/6+PZMLxjLS1iFIHJcK8YAA18O8LBtL0YbyshGOAB+gX3xNKsUUvukZBTyOg3kAy8FvPAVHbcONnuKLenDZgPsYQza6uHBKqt4o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782324209; c=relaxed/simple; bh=QO23kDMImtM+5HOMNrMXLHItHj21ff677Zh529A456k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iV7Me7AoaNffL9/HCR2LpdzKaESAcp4IqUFE+p6lUezYHscW+YXbRSRu2QBPOjfM/TEWNgng6EQteVfi//JhEaw0Ixx+4yz6JZF2XIuFasc1Vf1o5FlWYu1CDUvnTkX2cE7xWlnfTYyBrtw5xxyDCCJwnHE2JgLEDaSElIG43jg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=etnhE0UE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="etnhE0UE" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 1E4371F000E9; Wed, 24 Jun 2026 18:03:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782324208; bh=rpMUP6qY4/gUuajVubQNXi13lPGi6siMMKZVoDS+Kb0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=etnhE0UERKjfGnj++pfg5gIAVWxOwmMipcOGdwJ7tnK3bQsVlatIG7Lw0yZUUtDE5 vyg4QZ6JZIhWzKrMgD6hmi2FegELsqfKTWcWhFXQKXEMIIcVWWEEVxR0Sdtb8/QU1a NjIXOKpD8UX+FgJRpVLy8kY+6urD8AsWR+obgnDHQGxxT4S63GD0urlxNCEoqKwQB7 tihb0t6ynzxi9JAjD2u4ny2ZeZLzX84PVJdDq74G8YYvTIoRJw86v0/HqOB3UdHUog i3bevv7WrBgSDdfbMxEUYpTvklt8G7OKeBQBummCOfarnFmFRsNJqoyyj+VRPx0Dcr 7qnrXEDMYcWSw== Date: Wed, 24 Jun 2026 11:03:27 -0700 From: "Darrick J. Wong" To: Kanchan Joshi Cc: brauner@kernel.org, hch@lst.de, dgc@kernel.org, jack@suse.cz, cem@kernel.org, axboe@kernel.dk, kbusch@kernel.org, ritesh.list@gmail.com, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, gost.dev@samsung.com Subject: Re: [PATCH v3 1/6] fs: add generic write-stream management ioctl Message-ID: <20260624180327.GV6078@frogsfrogsfrogs> References: <20260616180555.33338-1-joshi.k@samsung.com> <20260616180555.33338-2-joshi.k@samsung.com> Precedence: bulk X-Mailing-List: linux-block@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: <20260616180555.33338-2-joshi.k@samsung.com> On Tue, Jun 16, 2026 at 11:35:50PM +0530, Kanchan Joshi wrote: > Wire up the userspace interface for write stream management via a new > vfs ioctl 'FS_IOC_WRITE_STEAM'. > Application communictes the intended operation using the 'op_flags' > field of the passed 'struct fs_write_stream'. > Valid flags are: > FS_WRITE_STREAM_OP_GET_MAX: Returns the number of available streams. > FS_WRITE_STREAM_OP_SET: Assign a specific stream value to the file. > FS_WRITE_STREAM_OP_GET: Query what stream value is set on the file. > > Application should query the available streams by using > FS_WRITE_STREAM_OP_GET_MAX first. > If returned value is N, valid stream values for the file are 0 to N. > Stream value 0 implies that no stream is set on the file. You might want to make that an explicit #define then. > Setting a larger value than available streams is rejected. > > Signed-off-by: Kanchan Joshi > --- > include/uapi/linux/fs.h | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h > index 13f71202845e..9e87271e610b 100644 > --- a/include/uapi/linux/fs.h > +++ b/include/uapi/linux/fs.h > @@ -338,6 +338,20 @@ struct file_attr { > /* Get logical block metadata capability details */ > #define FS_IOC_GETLBMD_CAP _IOWR(0x15, 2, struct logical_block_metadata_cap) > > +struct fs_write_stream { > + __u32 op_flags; /* IN: operation flags */ > + union { > + __u32 stream_id; /* IN/OUT: stream value to assign/guery */ "query"? --D > + __u32 max_streams; /* OUT: max streams values supported */ > + }; > + __u64 rsvd; > +}; > + > +#define FS_WRITE_STREAM_OP_GET_MAX (1 << 0) > +#define FS_WRITE_STREAM_OP_GET (1 << 1) > +#define FS_WRITE_STREAM_OP_SET (1 << 2) > + > +#define FS_IOC_WRITE_STREAM _IOWR('f', 135, struct fs_write_stream) > /* > * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS) > * > -- > 2.25.1 > >