From: Al Viro <viro@zeniv.linux.org.uk>
To: Jens Axboe <axboe@kernel.dk>
Cc: io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 03/10] fs: add namei support for doing a non-blocking path lookup
Date: Fri, 27 Dec 2019 00:42:06 +0000 [thread overview]
Message-ID: <20191227004206.GT4203@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20191213183632.19441-4-axboe@kernel.dk>
On Fri, Dec 13, 2019 at 11:36:25AM -0700, Jens Axboe wrote:
> If the fast lookup fails, then return -EAGAIN to have the caller retry
> the path lookup. This is in preparation for supporting non-blocking
> open.
NAK. We are not littering fs/namei.c with incremental broken bits
and pieces with uncertain eventual use.
And it's broken - lookup_slow() is *NOT* the only place that can and
does block. For starters, ->d_revalidate() can very well block and
it is called outside of lookup_slow(). So does ->d_automount().
So does ->d_manage().
I'm rather sceptical about the usefulness of non-blocking open, to be
honest, but in any case, one thing that is absolutely not going to
happen is piecewise introduction of such stuff without a discussion
of the entire design.
next prev parent reply other threads:[~2019-12-27 0:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-13 18:36 [PATCHSET 0/10] io_uring items for 5.6 Jens Axboe
2019-12-13 18:36 ` [PATCH 01/10] io_uring: add support for fallocate() Jens Axboe
2019-12-13 18:36 ` [PATCH 02/10] io_uring: remove 'sqe' parameter to the OP helpers that take it Jens Axboe
2019-12-13 18:36 ` [PATCH 03/10] fs: add namei support for doing a non-blocking path lookup Jens Axboe
2019-12-27 0:42 ` Al Viro [this message]
2019-12-27 5:05 ` Jens Axboe
2019-12-27 5:25 ` Jens Axboe
2019-12-27 15:45 ` Jens Axboe
2019-12-28 19:03 ` Jens Axboe
2019-12-13 18:36 ` [PATCH 04/10] fs: make build_open_flags() available internally Jens Axboe
2019-12-13 18:36 ` [PATCH 05/10] io_uring: add support for IORING_OP_OPENAT Jens Axboe
2019-12-13 18:36 ` [PATCH 06/10] fs: move filp_close() outside of __close_fd_get_file() Jens Axboe
2019-12-16 19:27 ` Jann Horn
2019-12-16 19:39 ` Jens Axboe
2019-12-13 18:36 ` [PATCH 07/10] io-wq: add support for uncancellable work Jens Axboe
2019-12-13 18:36 ` [PATCH 08/10] io_uring: add support for IORING_OP_CLOSE Jens Axboe
2019-12-13 18:36 ` [PATCH 09/10] io_uring: use u64_to_user_ptr() consistently Jens Axboe
2019-12-13 18:36 ` [PATCH 10/10] io_uring: avoid ring quiesce for fixed file set unregister and update Jens Axboe
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