From b4d878e23c7f574490ee4d6fd59ebd6819781dd1 Mon Sep 17 00:00:00 2001
From: Jan Blunck <jblunck@suse.de>
Date: Wed, 26 May 2010 14:44:51 -0700
Subject: st: use noop_llseek() instead of default_llseek()

st_open() suggests that llseek() doesn't work: "We really want to do
nonseekable_open(inode, filp); here, but some versions of tar incorrectly
call lseek on tapes and bail out if that fails.  So we disallow pread()
and pwrite(), but permit lseeks."

Instead of using the fallback default_llseek() the driver should use
noop_llseek() which leaves the file->f_pos untouched but succeeds.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kai Makisara <Kai.Makisara@kolumbus.fi>
Cc: Willem Riede <osst@riede.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 drivers/scsi/st.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'drivers')

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 3ea1a713ef2..24211d0efa6 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -3962,6 +3962,7 @@ static const struct file_operations st_fops =
 	.open =		st_open,
 	.flush =	st_flush,
 	.release =	st_release,
+	.llseek =	noop_llseek,
 };
 
 static int st_probe(struct device *dev)
-- 
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