From: Al Viro <viro@zeniv.linux.org.uk>
To: Omar Sandoval <osandov@osandov.com>
Cc: Trond Myklebust <trondmy@hammerspace.com>,
"amir73il@gmail.com" <amir73il@gmail.com>,
"dhowells@redhat.com" <dhowells@redhat.com>,
"lsf-pc@lists.linux-foundation.org"
<lsf-pc@lists.linux-foundation.org>, "hch@lst.de" <hch@lst.de>,
"miklos@szeredi.hu" <miklos@szeredi.hu>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [LSF/MM/BPF TOPIC] Allowing linkat() to replace the destination
Date: Fri, 17 Jan 2020 16:59:04 +0000 [thread overview]
Message-ID: <20200117165904.GN8904@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200117163616.GA282555@vader>
On Fri, Jan 17, 2020 at 08:36:16AM -0800, Omar Sandoval wrote:
> The semantics I implemented in my series were basically "linkat with
> AT_REPLACE replaces the target iff rename would replace the target".
> Therefore, symlinks are replaced, not followed, and mountpoints get
> EXDEV. In my opinion that's both sane and unsurprising.
Umm... EXDEV in rename() comes when _parents_ are on different mounts.
rename() over a mountpoint is EBUSY if it has mounts in caller's
namespace, but it succeeds (and detaches all mounts on the victim
in any namespaces) otherwise.
When are you returning EXDEV? Incidentally, mounts _are_ traversed on
the link source, so what should that variant do when /tmp/foo is
a mountpoint and you feed it "/tmp/foo" both for source and target?
next prev parent reply other threads:[~2020-01-17 16:59 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-17 12:49 [LSF/MM/BPF TOPIC] Allowing linkat() to replace the destination David Howells
2020-01-17 14:33 ` Trond Myklebust
2020-01-17 15:46 ` Al Viro
2020-01-17 16:12 ` Trond Myklebust
2020-01-17 16:48 ` Al Viro
2020-01-17 16:36 ` Omar Sandoval
2020-01-17 16:59 ` Al Viro [this message]
2020-01-17 17:28 ` Omar Sandoval
2020-01-17 18:17 ` Al Viro
2020-01-17 20:22 ` Omar Sandoval
2020-01-17 22:22 ` Al Viro
2020-01-17 23:54 ` Omar Sandoval
2020-01-18 0:47 ` Al Viro
2020-01-18 1:17 ` Omar Sandoval
2020-01-18 2:20 ` Al Viro
2020-01-21 23:05 ` Omar Sandoval
2020-01-22 6:57 ` Amir Goldstein
2020-01-22 22:10 ` Omar Sandoval
2020-01-23 3:47 ` Al Viro
2020-01-23 7:16 ` Dave Chinner
2020-01-23 7:47 ` Amir Goldstein
2020-01-24 21:25 ` Dave Chinner
2020-01-31 5:24 ` Darrick J. Wong
2020-01-31 5:29 ` hch
2020-01-31 7:00 ` Amir Goldstein
2020-01-31 20:33 ` Omar Sandoval
2020-01-31 21:55 ` Amir Goldstein
2020-01-28 1:27 ` Omar Sandoval
2020-01-28 14:35 ` David Howells
2020-01-31 5:31 ` hch
2020-01-31 8:04 ` David Howells
2020-01-31 8:56 ` Amir Goldstein
2020-01-22 9:53 ` David Howells
2020-01-17 14:47 ` David Howells
2020-01-17 14:56 ` Trond Myklebust
2020-01-17 16:01 ` Al Viro
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