Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley
        Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United
        Kingdom.
        Registered in England and Wales under Company Registration No. 3798903
From:   David Howells <dhowells@redhat.com>
In-Reply-To: <36eda01e-502e-b93d-9098-77ed5a16f33c@kernel.dk>
References: <36eda01e-502e-b93d-9098-77ed5a16f33c@kernel.dk> <20230630152524.661208-1-dhowells@redhat.com> <20230630152524.661208-4-dhowells@redhat.com>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     dhowells@redhat.com, Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Hillf Danton <hdanton@sina.com>,
        Christian Brauner <brauner@kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Christoph Hellwig <hch@lst.de>,
        Christian Brauner <christian@brauner.io>
Subject: Re: [RFC PATCH 03/11] vfs: Use init_kiocb() to initialise new IOCBs
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <662383.1688140818.1@warthog.procyon.org.uk>
Date:   Fri, 30 Jun 2023 17:00:18 +0100
Message-ID: <662384.1688140818@warthog.procyon.org.uk>
Precedence: bulk

Jens Axboe <axboe@kernel.dk> wrote:

> One concern here is that we're using IOCB_WRITE here to tell if
> sb_start_write() has been done or not, and hence whether
> kiocb_end_write() needs to be called. You know set it earlier, which
> means if we get a failure if we need to setup async data, then we know
> have IOCB_WRITE set at that point even though we did not call
> sb_start_write().

Hmmm...  It's set earlier in a number of places anyway - __cachefiles_write()
for example.

Btw, can you please put some comments on the IOCB_* constants?  I have to
guess at what they mean and how they're meant to be used.  Or better still,
get Christoph to write Documentation/core-api/iocb.rst describing the API? ;-)

David