From: Al Viro <viro@ZenIV.linux.org.uk>
To: Evgeniy Polyakov <zbr@ioremap.net>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [WTF] ... is going on with current->fs->{root,mnt} accesses in pohmelfs
Date: Thu, 11 Feb 2010 03:02:54 +0000 [thread overview]
Message-ID: <20100211030253.GQ30031@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20100210212933.GA19919@ioremap.net>
On Thu, Feb 11, 2010 at 12:29:33AM +0300, Evgeniy Polyakov wrote:
> On Wed, Feb 10, 2010 at 09:02:48PM +0000, Al Viro (viro@ZenIV.linux.org.uk) wrote:
> > Which would be... ? E.g. between writepages() and rename(). What serializes
> > your write_inode_create() wrt renames? IOW, how can the server decide that
> > data from writepages() should go to the same object regardless of the
> > rename?
>
> rename and some other metadata operations as well as write itself
> request remote lock (if not grabbed already), acknowledge forces writeback to old path.
Um. You do realize that d_move() happens with none of your locks held,
right? It's done in vfs_rename_{other,dir}() and the only thing held
is s_vfs_rename_sem and i_mutex on parents. How could your code in
writeback be able to distinguish
rename() is done
d_move() has happened, we see new pathname in dcache
from
rename() is done
d_move() has not yet happened, we see old pathname in dcache
and generate the right on-the-wire traffic in both cases? Note that here
server has already seen rename request; as far as server and client are
concerned the rename() is over.
next prev parent reply other threads:[~2010-02-11 3:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-10 10:04 [WTF] ... is going on with current->fs->{root,mnt} accesses in pohmelfs Al Viro
2010-02-10 10:12 ` Evgeniy Polyakov
2010-02-10 10:24 ` Al Viro
2010-02-10 10:45 ` Evgeniy Polyakov
2010-02-10 11:00 ` Al Viro
2010-02-10 11:11 ` Evgeniy Polyakov
2010-02-10 11:59 ` Al Viro
2010-02-10 13:30 ` Evgeniy Polyakov
2010-02-10 21:02 ` Al Viro
2010-02-10 21:29 ` Evgeniy Polyakov
2010-02-11 3:02 ` Al Viro [this message]
2010-02-11 15:08 ` Evgeniy Polyakov
2010-02-11 17:10 ` Al Viro
2010-02-11 19:13 ` Evgeniy Polyakov
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