From: David Howells <dhowells@redhat.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: dhowells@redhat.com, torvalds@linux-foundation.org,
linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 05/20] afs: Implement @sys substitution handling
Date: Fri, 06 Apr 2018 09:08:55 +0100 [thread overview]
Message-ID: <22233.1523002135@warthog.procyon.org.uk> (raw)
In-Reply-To: <20180406065118.GZ30522@ZenIV.linux.org.uk>
Al Viro <viro@ZenIV.linux.org.uk> wrote:
> > +static struct dentry *afs_lookup_atsys(struct inode *dir, struct dentry *dentry,
> > + struct key *key)
> > +{
>
> > + ret = lookup_one_len(buf, parent, len);
>
> Er... Parent is locked only shared here and lookup_one_len() seriously
> depends upon exclusive lock. As it is, race with lookup of the full name
> will mess the things up very badly.
How should it be done? Do I have to use d_alloc_parallel(), analogous to
lookup_slow() without taking the rwsem again?
David
PS: Can you stick a banner comment on d_alloc_parallel() describing it?
next prev parent reply other threads:[~2018-04-06 8:09 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-05 20:29 [PATCH 00/20] afs: Fixes and development David Howells
2018-04-05 20:29 ` [PATCH 01/20] vfs: Remove the const from dir_context::actor David Howells
2018-04-05 20:29 ` [PATCH 02/20] afs: Fix checker warnings David Howells
2018-04-12 5:38 ` Christoph Hellwig
2018-04-12 6:06 ` Al Viro
2018-04-05 20:29 ` [PATCH 03/20] afs: Don't over-increment the cell usage count when pinning it David Howells
2018-04-05 20:29 ` [PATCH 04/20] afs: Prospectively look up extra files when doing a single lookup David Howells
2018-04-05 20:30 ` [PATCH 05/20] afs: Implement @sys substitution handling David Howells
2018-04-06 6:37 ` Christoph Hellwig
2018-04-06 6:51 ` Al Viro
2018-04-06 8:08 ` David Howells [this message]
2018-04-06 8:13 ` David Howells
2018-04-06 17:54 ` Nikolay Borisov
2018-04-06 9:04 ` David Howells
2018-04-06 10:32 ` David Howells
2018-04-05 20:30 ` [PATCH 06/20] afs: Implement @cell " David Howells
2018-04-05 20:30 ` [PATCH 07/20] afs: Dump bad status record David Howells
2018-04-05 20:30 ` [PATCH 08/20] afs: Introduce a statistics proc file David Howells
2018-04-05 20:30 ` [PATCH 09/20] afs: Init inode before accessing cache David Howells
2018-04-05 20:30 ` [PATCH 10/20] afs: Make it possible to get the data version in readpage David Howells
2018-04-05 20:30 ` [PATCH 11/20] afs: Rearrange status mapping David Howells
2018-04-05 20:30 ` [PATCH 12/20] afs: Keep track of invalid-before version for dentry coherency David Howells
2018-04-05 20:30 ` [PATCH 13/20] afs: Split the dynroot stuff out and give it its own ops tables David Howells
2018-04-05 20:31 ` [PATCH 14/20] afs: Fix directory handling David Howells
2018-04-05 20:31 ` [PATCH 15/20] afs: Split the directory content defs into a header David Howells
2018-04-05 20:31 ` [PATCH 16/20] afs: Adjust the directory XDR structures David Howells
2018-04-05 20:31 ` [PATCH 17/20] afs: Locally edit directory data for mkdir/create/unlink/ David Howells
2018-04-05 20:31 ` [PATCH 18/20] afs: Trace protocol errors David Howells
2018-04-05 20:31 ` [PATCH 19/20] afs: Add stats for data transfer operations David Howells
2018-04-05 20:31 ` [PATCH 20/20] afs: Do better accretion of small writes on newly created content David Howells
2018-04-07 16:50 ` [PATCH 00/20] afs: Fixes and development Linus Torvalds
2018-04-07 17:19 ` Al Viro
2018-04-07 18:04 ` Linus Torvalds
2018-04-08 7:36 ` David Howells
2018-04-11 14:37 ` David Howells
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