From: David Howells <dhowells@redhat.com>
To: Karel Zak <kzak@redhat.com>
Cc: dhowells@redhat.com, viro@zeniv.linux.org.uk,
linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-kernel@vger.kernel.org, mszeredi@redhat.com
Subject: Re: [PATCH 4/9] Implement fsopen() to prepare for a mount
Date: Thu, 04 May 2017 14:06:51 +0100 [thread overview]
Message-ID: <15169.1493903211@warthog.procyon.org.uk> (raw)
In-Reply-To: <20170504104045.6sh3dqofcii6kk2e@ws.net.home>
Karel Zak <kzak@redhat.com> wrote:
> > write(mfd, "d /dev/sdb1"); // note I'm ignoring write's length arg
>
> Not sure about 'd', in many cases it is not device, for mount(2)
> syscall we call it "source".
sys_mount() calls it devname. But whatever - I'm not particularly attached to
the letter 'd' for this.
> The very basic mount(2) problem is that you have to parse
> /proc/self/mountinfo to get information about the mounted filesystem.
> It seems that your read() is also one way communication.
>
> What we really need is to have a way how to specify *what* you want to
> read. The error message is not enough, I want to know the finally used
> mount options, mount ID, etc. It would be nice to have something like
>
>
> fsmount(mfd, AT_FDCWD, "/mnt", 0);
>
> write(mfd, "o");
> read(mfd, ....); // read mount options
>
> write(mdf, "i");
> read(mfd, ....); // read mount ID
>
>
> but it seems ugly. Maybe introduce another function like
>
> fsinfo(mdf, "o", buf, bufsz)
>
> to get mount options (etc.) and to avoid separate write & read.
What is it you're trying to do? Just read back the state of the new mount?
Or read back the state of a specified extant mount?
David
next prev parent reply other threads:[~2017-05-04 13:06 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-03 16:04 [RFC][PATCH 0/9] VFS: Introduce mount context David Howells
2017-05-03 16:04 ` [PATCH 1/9] Provide a function to create a NUL-terminated string from unterminated data David Howells
2017-05-03 16:55 ` Jeff Layton
2017-05-03 19:26 ` Rasmus Villemoes
2017-05-03 20:13 ` David Howells
2017-05-03 16:04 ` [PATCH 2/9] Clean up whitespace in fs/namespace.c David Howells
2017-05-03 16:04 ` [PATCH 3/9] VFS: Introduce a mount context David Howells
2017-05-03 18:13 ` Jeff Layton
2017-05-03 18:26 ` Joe Perches
2017-05-03 20:38 ` Matthew Wilcox
2017-05-03 21:36 ` Joe Perches
2017-05-04 6:28 ` Julia Lawall
2017-05-03 21:17 ` David Howells
2017-05-03 18:37 ` David Howells
2017-05-03 18:43 ` Joe Perches
2017-05-03 20:11 ` David Howells
2017-05-04 9:27 ` David Howells
2017-05-04 14:34 ` Joe Perches
2017-05-03 21:43 ` Rasmus Villemoes
2017-05-04 10:22 ` David Howells
2017-05-08 15:05 ` Miklos Szeredi
2017-05-08 22:57 ` David Howells
2017-05-09 8:03 ` Miklos Szeredi
2017-05-10 12:41 ` Karel Zak
2017-05-09 9:32 ` David Howells
2017-05-09 11:04 ` Miklos Szeredi
2017-05-09 9:41 ` David Howells
2017-05-09 12:02 ` Miklos Szeredi
2017-05-09 18:51 ` Jeff Layton
2017-05-10 7:24 ` Miklos Szeredi
2017-05-10 8:05 ` David Howells
2017-05-10 13:20 ` Jeff Layton
2017-05-10 13:30 ` Miklos Szeredi
2017-05-10 13:33 ` Miklos Szeredi
2017-05-10 13:48 ` Jeff Layton
2017-05-12 8:15 ` Miklos Szeredi
2017-05-10 13:31 ` David Howells
2017-05-10 13:37 ` Jeff Layton
2017-05-09 9:56 ` David Howells
2017-05-09 12:38 ` Miklos Szeredi
2017-05-03 16:05 ` [PATCH 4/9] Implement fsopen() to prepare for a mount David Howells
2017-05-03 18:37 ` Jeff Layton
2017-05-03 18:41 ` David Howells
2017-05-03 20:44 ` Rasmus Villemoes
2017-05-04 10:40 ` Karel Zak
2017-05-04 12:55 ` David Howells
2017-05-04 12:58 ` David Howells
2017-05-04 13:06 ` David Howells [this message]
2017-05-04 13:34 ` Karel Zak
2017-05-09 18:40 ` Jeff Layton
2017-05-08 15:10 ` Miklos Szeredi
2017-05-08 23:09 ` David Howells
2017-05-03 16:05 ` [PATCH 5/9] Implement fsmount() to effect a pre-configured mount David Howells
2017-05-03 16:05 ` [PATCH 6/9] Sample program for driving fsopen/fsmount David Howells
2017-05-03 16:05 ` [PATCH 7/9] procfs: Move proc_fill_super() to fs/proc/root.c David Howells
2017-05-03 16:05 ` [PATCH 8/9] proc: Support the mount context in procfs David Howells
2017-05-03 16:05 ` [PATCH 9/9] NFS: Support the mount context and fsopen() David Howells
2017-05-03 16:44 ` [RFC][PATCH 0/9] VFS: Introduce mount context Jeff Layton
2017-05-03 16:50 ` David Howells
2017-05-03 17:27 ` Jeff Layton
2017-05-05 14:35 ` Miklos Szeredi
2017-05-05 15:47 ` David Howells
2017-05-08 8:25 ` Miklos Szeredi
2017-05-08 8:35 ` David Howells
2017-05-08 8:43 ` Miklos Szeredi
2017-05-08 17:03 ` Djalal Harouni
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