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From: Frederic Weisbecker <fweisbec@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	John Kacur <jkacur@redhat.com>,
	Sven-Thorsten Dietrich <sven@thebigcorporation.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Alessio Igor Bogani <abogani@texware.it>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Greg KH <gregkh@suse.de>
Subject: [PATCH] nvram: Drop the bkl from nvram_llseek()
Date: Fri,  9 Oct 2009 21:20:30 +0200	[thread overview]
Message-ID: <1255116030-6929-1-git-send-email-fweisbec@gmail.com> (raw)

There is nothing to protect inside nvram_llseek(), the file
offset doesn't need to be protected and nvram_len is only
initialized from an __init path.

It's safe to remove the big kernel lock there.

(Is this file still used? I can't even build it,
looks like it is built under CONFIG_GENERIC_NVRAM but this
option is referenced nowhere except in powerpc defconfigs)

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: Sven-Thorsten Dietrich <sven@thebigcorporation.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alessio Igor Bogani <abogani@texware.it>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <gregkh@suse.de>
---
 drivers/char/generic_nvram.c |    8 +++-----
 1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/char/generic_nvram.c b/drivers/char/generic_nvram.c
index ef31738..c49200e 100644
--- a/drivers/char/generic_nvram.c
+++ b/drivers/char/generic_nvram.c
@@ -32,7 +32,6 @@ static ssize_t nvram_len;
 
 static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
 {
-	lock_kernel();
 	switch (origin) {
 	case 1:
 		offset += file->f_pos;
@@ -41,12 +40,11 @@ static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
 		offset += nvram_len;
 		break;
 	}
-	if (offset < 0) {
-		unlock_kernel();
+	if (offset < 0)
 		return -EINVAL;
-	}
+
 	file->f_pos = offset;
-	unlock_kernel();
+
 	return file->f_pos;
 }
 
-- 
1.6.2.3


             reply	other threads:[~2009-10-09 19:21 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-09 19:20 Frederic Weisbecker [this message]
2009-10-09 19:27 ` [PATCH] nvram: Drop the bkl from nvram_llseek() Thomas Gleixner
2009-10-09 19:29   ` Frederic Weisbecker
2009-10-14 15:48 ` [tip:bkl/drivers] " tip-bot for Frederic Weisbecker

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