linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: pragalla@codeaurora.org
To: miklos@szeredi.hu
Cc: stummala@codeaurora.org, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH V1] fuse: Set fuse request error upon fuse abort connection
Date: Mon, 10 May 2021 13:22:23 +0530	[thread overview]
Message-ID: <c0c0c33be51672f01d4f7a2e097bb978@codeaurora.org> (raw)
In-Reply-To: <1618582752-26178-1-git-send-email-pragalla@codeaurora.org>

Hi Miklos,

Did you get a chance to look on the below change ?
could you please review and provide your comments if any.

Thanks and Regards,
Pradeep

On 2021-04-16 19:49, Pradeep P V K wrote:
> There is a minor race in setting the fuse out request error
> between fuse_abort_conn() and fuse_dev_do_read() as explained
> below.
> 
> Thread-1			  Thread-2
> ========			  ========
> ->fuse_simple_request()           ->shutdown
>   ->__fuse_request_send()
>     ->queue_request()		->fuse_abort_conn()
> ->fuse_dev_do_read()                ->acquire(fpq->lock)
>   ->wait_for(fpq->lock) 	  ->set err to all req's in fpq->io
> 				  ->release(fpq->lock)
>   ->acquire(fpq->lock)
>   ->add req to fpq->io
> 
> The above scenario may cause Thread-1 request to add into
> fpq->io list after Thread-2 sets -ECONNABORTED err to all
> its requests in fpq->io list. This leaves Thread-1 request
> with unset err and this further misleads as a completed
> request without an err set upon request_end().
> 
> Handle this by setting the err appropriately.
> 
> Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>
> ---
>  fs/fuse/dev.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index a5ceccc..102c56f 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1283,6 +1283,7 @@ static ssize_t fuse_dev_do_read(struct fuse_dev
> *fud, struct file *file,
>  	clear_bit(FR_LOCKED, &req->flags);
>  	if (!fpq->connected) {
>  		err = fc->aborted ? -ECONNABORTED : -ENODEV;
> +		req->out.h.error = err;
>  		goto out_end;
>  	}
>  	if (err) {

  reply	other threads:[~2021-05-10  7:52 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-16 14:19 Pradeep P V K
2021-05-10  7:52 ` pragalla [this message]
2021-05-10 14:05   ` Miklos Szeredi
2021-06-21  7:48 ` Miklos Szeredi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=c0c0c33be51672f01d4f7a2e097bb978@codeaurora.org \
    --to=pragalla@codeaurora.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=miklos@szeredi.hu \
    --cc=stummala@codeaurora.org \
    --subject='Re: [PATCH V1] fuse: Set fuse request error upon fuse abort connection' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).