From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [PATCH 05/23] vfs: Teach lseek to use file_hotplug_lock Date: Mon, 1 Jun 2009 14:50:30 -0700 Message-ID: <1243893048-17031-5-git-send-email-ebiederm@xmission.com> References: Cc: , , , , Hugh Dickins , Tejun Heo , Alexey Dobriyan , Linus Torvalds , Alan Cox , Greg Kroah-Hartman , Nick Piggin , Andrew Morton , Christoph Hellwig , "Eric W. Biederman" , "Eric W. Biederman" To: Al Viro Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]:35855 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753043AbZFAVu6 (ORCPT ); Mon, 1 Jun 2009 17:50:58 -0400 In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Eric W. Biederman Signed-off-by: Eric W. Biederman --- fs/read_write.c | 24 +++++++++++++++++------- 1 files changed, 17 insertions(+), 7 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index 9d1e76b..c9511ce 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -136,14 +136,24 @@ EXPORT_SYMBOL(default_llseek); loff_t vfs_llseek(struct file *file, loff_t offset, int origin) { loff_t (*fn)(struct file *, loff_t, int); + loff_t retval = -ESPIPE; - fn = no_llseek; - if (file->f_mode & FMODE_LSEEK) { - fn = default_llseek; - if (file->f_op && file->f_op->llseek) - fn = file->f_op->llseek; - } - return fn(file, offset, origin); + if (!(file->f_mode & FMODE_LSEEK)) + goto out; + + retval = -EIO; + if (!file_hotplug_read_trylock(file)) + goto out; + + fn = default_llseek; + if (file->f_op && file->f_op->llseek) + fn = file->f_op->llseek; + + retval = fn(file, offset, origin); + + file_hotplug_read_unlock(file); +out: + return retval; } EXPORT_SYMBOL(vfs_llseek); -- 1.6.3.1.54.g99dd.dirty