From: Jens Axboe <axboe@kernel.dk>
To: Amir Goldstein <amir73il@gmail.com>,
Zhang Tianci <zhangtianci.1997@bytedance.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>,
Daniel Rosenberg <drosen@google.com>,
Paul Lawrence <paullawrence@google.com>,
Alessio Balsini <balsini@android.com>,
fuse-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org,
Christian Brauner <brauner@kernel.org>
Subject: Re: [External] [PATCH v13 08/10] fuse: update inode size/mtime after passthrough write
Date: Tue, 26 Sep 2023 09:31:29 -0600 [thread overview]
Message-ID: <1dea57e7-87d0-4ed7-9142-3a46dab73805@kernel.dk> (raw)
In-Reply-To: <CAOQ4uxh5EFz-50vBLnfd0_+4uzg6v7Vd_6Wg4yE7uYn3+i3uoQ@mail.gmail.com>
On 9/25/23 4:43 AM, Amir Goldstein wrote:
> Jens,
>
> Are there any IOCB flags that overlayfs (or backing_aio) need
> to set or clear, besides IOCB_DIO_CALLER_COMP, that
> would prevent calling completion from interrupt context?
There are a few flags that may get set (like WAITQ or ALLOC_CACHE), but
I think that should all work ok as-is as the former is just state in
that iocb and that is persistent (and only for the read path), and
ALLOC_CACHE should just be propagated.
> Or is the proper way to deal with this is to defer completion
> to workqueue in the common backing_aio helpers that
> I am re-factoring from overlayfs?
No, deferring to a workqueue would defeat the purpose of the flag, which
is telling you that the caller will ensure that the end_io callback will
happen from task context and need not be deferred to a workqueue. I can
take a peek at how to wire it up properly for overlayfs, have some
travel coming up in a few days.
> IIUC, that could also help overlayfs support
> IOCB_DIO_CALLER_COMP?
>
> Is my understanding correct?
If you peek at fs.h and find the CALLER_COMP references, it'll tell you
a bit about how it works. This is new with the 6.6-rc kernel, there's a
series of patches from me that went in through the iomap tree that
hooked that up. Those commits have an explanation as well.
--
Jens Axboe
next prev parent reply other threads:[~2023-09-26 15:31 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-19 12:56 [PATCH v13 00/10] fuse: Add support for passthrough read/write Amir Goldstein
2023-05-19 12:56 ` [PATCH v13 01/10] fs: Generic function to convert iocb to rw flags Amir Goldstein
2023-05-19 12:56 ` [PATCH v13 02/10] fuse: Definitions and ioctl for passthrough Amir Goldstein
2023-05-19 15:12 ` Miklos Szeredi
2023-05-20 10:20 ` Amir Goldstein
2023-05-22 14:50 ` Miklos Szeredi
2023-05-24 10:00 ` Amir Goldstein
2023-05-19 12:56 ` [PATCH v13 03/10] fuse: Passthrough initialization and release Amir Goldstein
2023-05-19 12:56 ` [PATCH v13 04/10] fuse: Introduce synchronous read and write for passthrough Amir Goldstein
2023-05-19 12:57 ` [PATCH v13 05/10] fuse: Handle asynchronous read and write in passthrough Amir Goldstein
2023-05-22 15:20 ` Miklos Szeredi
2023-05-24 10:03 ` Amir Goldstein
2023-08-21 15:27 ` Amir Goldstein
2023-08-22 10:18 ` Amir Goldstein
2023-08-22 11:03 ` Miklos Szeredi
2023-08-22 13:22 ` Amir Goldstein
2023-08-22 14:06 ` Miklos Szeredi
2023-08-24 12:11 ` Amir Goldstein
2023-08-29 12:42 ` Miklos Szeredi
2023-05-19 12:57 ` [PATCH v13 06/10] fuse: Use daemon creds in passthrough mode Amir Goldstein
2023-05-19 12:57 ` [PATCH v13 07/10] fuse: Introduce passthrough for mmap Amir Goldstein
2023-05-19 12:57 ` [PATCH v13 08/10] fuse: update inode size/mtime after passthrough write Amir Goldstein
2023-09-25 6:41 ` [External] " Zhang Tianci
2023-09-25 10:43 ` Amir Goldstein
2023-09-26 15:31 ` Jens Axboe [this message]
2023-09-26 15:48 ` Amir Goldstein
2023-09-26 16:19 ` Jens Axboe
2023-09-26 16:56 ` Amir Goldstein
2023-05-19 12:57 ` [PATCH v13 09/10] fuse: invalidate atime after passthrough read/mmap Amir Goldstein
2023-05-19 12:57 ` [PATCH v13 10/10] fuse: setup a passthrough fd without a permanent backing id Amir Goldstein
2023-06-06 10:22 ` Fwd: " Miklos Szeredi
2023-06-06 11:00 ` [fuse-devel] " Amir Goldstein
2023-06-06 12:46 ` Miklos Szeredi
2023-05-20 10:28 ` [PATCH v13 00/10] fuse: Add support for passthrough read/write Amir Goldstein
2023-06-06 9:13 ` Amir Goldstein
2023-06-06 9:49 ` Miklos Szeredi
2023-06-06 11:19 ` Amir Goldstein
2023-06-06 13:06 ` Miklos Szeredi
2023-08-29 18:14 ` Amir Goldstein
2023-09-20 13:56 ` Amir Goldstein
2023-09-20 18:15 ` Miklos Szeredi
2023-09-21 7:33 ` Amir Goldstein
2023-09-21 8:21 ` Miklos Szeredi
2023-09-21 9:17 ` Amir Goldstein
2023-09-21 9:30 ` Miklos Szeredi
2023-09-21 10:31 ` Amir Goldstein
2023-09-21 11:50 ` Miklos Szeredi
2023-09-22 12:45 ` Amir Goldstein
2023-10-08 17:53 ` Amir Goldstein
2023-10-10 14:31 ` Miklos Szeredi
2023-10-10 15:14 ` Amir Goldstein
2023-10-14 16:01 ` Amir Goldstein
2023-10-16 10:30 ` Amir Goldstein
2023-10-16 13:21 ` Miklos Szeredi
2023-10-16 19:16 ` Bernd Schubert
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