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From: Al Viro <viro@zeniv.linux.org.uk>
To: Jeff Layton <jlayton@kernel.org>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	sargun@sargun.me, amir73il@gmail.com, vgoyal@redhat.com
Subject: Re: [PATCH][RESEND] vfs: serialize updates to file->f_sb_err with f_lock
Date: Mon, 4 Jan 2021 18:57:17 +0000	[thread overview]
Message-ID: <20210104185717.GK3579531@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20210104184347.90598-1-jlayton@kernel.org>

On Mon, Jan 04, 2021 at 01:43:47PM -0500, Jeff Layton wrote:
> @@ -172,7 +172,12 @@ SYSCALL_DEFINE1(syncfs, int, fd)
>  	ret = sync_filesystem(sb);
>  	up_read(&sb->s_umount);
>  
> -	ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);
> +	if (errseq_check(&sb->s_wb_err, f.file->f_sb_err)) {
> +		/* Something changed, must use slow path */
> +		spin_lock(&f.file->f_lock);
> +		ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);
> +		spin_unlock(&f.file->f_lock);
> +	}

	Is there any point bothering with the fastpath here?
I mean, look at the up_read() immediately prior to that thing...

  reply	other threads:[~2021-01-04 18:58 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-04 18:43 [PATCH][RESEND] vfs: serialize updates to file->f_sb_err with f_lock Jeff Layton
2021-01-04 18:57 ` Al Viro [this message]
2021-01-04 19:00   ` Jeff Layton

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