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From: "hch@infradead.org" <hch@infradead.org>
To: Trond Myklebust <trondmy@hammerspace.com>
Cc: "hch@infradead.org" <hch@infradead.org>,
	"jack@suse.cz" <jack@suse.cz>,
	"chuck.lever@oracle.com" <chuck.lever@oracle.com>,
	"linux-api@vger.kernel.org" <linux-api@vger.kernel.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"brauner@kernel.org" <brauner@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"alex.aring@gmail.com" <alex.aring@gmail.com>,
	"cyphar@cyphar.com" <cyphar@cyphar.com>,
	"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"jlayton@kernel.org" <jlayton@kernel.org>,
	"amir73il@gmail.com" <amir73il@gmail.com>,
	"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH RFC v2] fhandle: expose u64 mount id to name_to_handle_at(2)
Date: Mon, 27 May 2024 09:29:48 -0700	[thread overview]
Message-ID: <ZlS0_DWzGk24GYZA@infradead.org> (raw)
In-Reply-To: <86065f6a4f3d2f3d78f39e7a276a2d6e25bfbc9d.camel@hammerspace.com>

On Mon, May 27, 2024 at 03:38:40PM +0000, Trond Myklebust wrote:
> > It
> > does not matter what mount you use to access it.
> 
> Sure. However if you are providing a path argument, then presumably you
> need to know which file system (aka super_block) it eventually resolves
> to.

Except that you can't, at least not without running into potential
races.  The only way to fix a race vs unmount/remount is to include
the fsid part in the kernel generated file handle.

> 
> If your use case isn't NFS servers, then what use case are you
> targeting, and how do you expect those applications to use this API?

The main user of the open by handle syscalls seems to be fanotify
magic.


  reply	other threads:[~2024-05-27 16:29 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-23 20:57 [PATCH RFC v2] fhandle: expose u64 mount id to name_to_handle_at(2) Aleksa Sarai
2024-05-24  4:58 ` Amir Goldstein
2024-05-26  9:25 ` Christoph Hellwig
2024-05-26 19:01   ` Aleksa Sarai
2024-05-27 11:47     ` Christoph Hellwig
2024-05-27 12:29       ` Christian Brauner
2024-05-27 13:17         ` Christian Brauner
2024-05-27 15:47           ` Trond Myklebust
2024-05-28  7:05             ` Christian Brauner
2024-05-27 16:18         ` Christoph Hellwig
2024-05-27 13:34       ` Jan Kara
2024-05-27 16:24         ` Christoph Hellwig
2024-05-28  8:20           ` Christian Brauner
2024-05-28  8:28             ` Christoph Hellwig
2024-05-28  9:17               ` Christian Brauner
2024-05-28 10:55                 ` Christoph Hellwig
2024-05-28 12:04                   ` Christian Brauner
2024-05-28 13:22                     ` Christoph Hellwig
2024-05-28 13:28                       ` Miklos Szeredi
2024-05-29  6:34                         ` Christoph Hellwig
2024-06-01  8:12                         ` Aleksa Sarai
2024-06-03 10:30                           ` Jan Kara
2024-06-04  5:22                           ` Christoph Hellwig
2024-05-29  7:40                       ` Christian Brauner
2024-05-31  8:14                         ` Christoph Hellwig
2024-05-31 10:28                           ` Christian Brauner
2024-05-26 22:32   ` Trond Myklebust
2024-05-27 11:49     ` hch
2024-05-27 15:38       ` Trond Myklebust
2024-05-27 16:29         ` hch [this message]
2024-05-28  7:12           ` Christian Brauner
2024-05-28  7:15             ` hch
2024-05-28 10:11           ` Jan Kara
2024-05-28 10:56             ` hch
2024-05-28 23:25               ` Dave Chinner
2024-05-29  6:24                 ` hch
2024-05-29  7:23                   ` Amir Goldstein
2024-05-27 12:22   ` Christian Brauner

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