From: Hauke Mehrtens <hauke@hauke-m.de>
Date: Wed, 15 Sep 2010 20:42:32 +0000 (-0700)
Subject: compat: backport loff_t noop_llseek
X-Git-Tag: v2.6.37-rc1-1~19
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=764a6496348bc04e03434d5c6d8761e5f5e2b280;p=~emulex%2Ffor-vlad%2Fold%2Fcompat.git

compat: backport loff_t noop_llseek

This is needed by some debug parts of mac80211.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---

diff --git a/compat/compat-2.6.35.c b/compat/compat-2.6.35.c
index 0d702ed..abb08c7 100644
--- a/compat/compat-2.6.35.c
+++ b/compat/compat-2.6.35.c
@@ -31,4 +31,21 @@ int hex_to_bin(char ch)
 }
 EXPORT_SYMBOL(hex_to_bin);
 
+/**
+ * noop_llseek - No Operation Performed llseek implementation
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @origin:	type of seek
+ *
+ * This is an implementation of ->llseek useable for the rare special case when
+ * userspace expects the seek to succeed but the (device) file is actually not
+ * able to perform the seek. In this case you use noop_llseek() instead of
+ * falling back to the default implementation of ->llseek.
+ */
+loff_t noop_llseek(struct file *file, loff_t offset, int origin)
+{
+	return file->f_pos;
+}
+EXPORT_SYMBOL(noop_llseek);
+
 #endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2,6,35) */
diff --git a/include/linux/compat-2.6.35.h b/include/linux/compat-2.6.35.h
index f0562cd..32fd039 100644
--- a/include/linux/compat-2.6.35.h
+++ b/include/linux/compat-2.6.35.h
@@ -27,6 +27,8 @@ static inline wait_queue_head_t *sk_sleep(struct sock *sk)
 
 int hex_to_bin(char ch);
 
+extern loff_t noop_llseek(struct file *file, loff_t offset, int origin);
+
 #endif /* (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,35)) */
 
 #endif /* LINUX_26_35_COMPAT_H */