From: Arnd Bergmann <arnd@arndb.de>
To: Roland Dreier <rdreier@cisco.com>
Cc: Steve Wise <swise@opengridcomputing.com>,
linux-rdma@vger.kernel.org, linux-next@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] RDMA/cxgb4: Add default_llseek to debugfs files.
Date: Wed, 29 Sep 2010 21:17:54 +0200 [thread overview]
Message-ID: <201009292117.54828.arnd@arndb.de> (raw)
In-Reply-To: <adawrq431sr.fsf@cisco.com>
On Wednesday 29 September 2010 19:19:32 Roland Dreier wrote:
> > @@ -182,6 +182,7 @@ static const struct file_operations qp_debugfs_fops = {
> > .open = qp_open,
> > .release = qp_release,
> > .read = debugfs_read,
> > + .llseek = default_llseek,
> > };
>
> I think this could actually be generic_file_llseek (right, Arnd?).
The main difference between default_llseek and generic_file_llseek
is that default_llseek doesn't care about the maximum file size
of the underlying file system, which is ULONG_MAX on debugfs,
so they are equivalent.
In general, the preferred one is no_llseek for those files where
you know you do not need to seek. If you do, I'd use default_llseek
for character devices and generic_file_llseek for file systems
that set the s_maxbytes.
Arnd
next prev parent reply other threads:[~2010-09-29 19:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-29 14:11 [PATCH] RDMA/cxgb4: Add default_llseek to debugfs files Steve Wise
2010-09-29 17:19 ` Roland Dreier
2010-09-29 17:27 ` Steve Wise
2010-09-29 17:41 ` Roland Dreier
2010-09-29 17:49 ` Steve Wise
2010-09-29 17:50 ` Roland Dreier
2010-09-29 19:17 ` Arnd Bergmann [this message]
2010-09-29 19:21 ` Roland Dreier
2010-09-29 19:29 ` Arnd Bergmann
2010-09-29 19:40 ` Roland Dreier
2010-09-29 18:52 ` Roland Dreier
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