[PATCH 1/2] compat: backport loff_t noop_llseek

[PATCH 1/2] compat: backport loff_t noop_llseek

[Hauke Mehrtens]

This is needed by some debug parts of mac80211.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 compat/compat-2.6.35.c        |   17 +++++++++++++++++
 include/linux/compat-2.6.35.h |    2 ++
 2 files changed, 19 insertions(+), 0 deletions(-)

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 */
-- 
1.7.0.4

[PATCH 2/2] compat: backport list_for_each_entry_continue_rcu

[Hauke Mehrtens]

This is needed for new driver carl9170.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 include/linux/compat-2.6.31.h |   11 +++++++++++
 include/linux/compat-2.6.33.h |   14 ++++++++++++++
 2 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/include/linux/compat-2.6.31.h b/include/linux/compat-2.6.31.h
index 54ddefd..6c454cb 100644
--- a/include/linux/compat-2.6.31.h
+++ b/include/linux/compat-2.6.31.h
@@ -191,6 +191,17 @@ void compat_synchronize_threaded_irq(struct compat_threaded_irq *comp)
 	cancel_work_sync(&comp->work);
 }
 
+/**
+ * list_entry_rcu - get the struct for this entry
+ * @ptr:        the &struct list_head pointer.
+ * @type:       the type of the struct this is embedded in.
+ * @member:     the name of the list_struct within the struct.
+ *
+ * This primitive may safely run concurrently with the _rcu list-mutation
+ * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
+ */
+#define list_entry_rcu(ptr, type, member) \
+	container_of(rcu_dereference(ptr), type, member)
 
 #endif /* (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,31)) */
 
diff --git a/include/linux/compat-2.6.33.h b/include/linux/compat-2.6.33.h
index e4dff72..e7e20d9 100644
--- a/include/linux/compat-2.6.33.h
+++ b/include/linux/compat-2.6.33.h
@@ -98,6 +98,20 @@ int pccard_loop_tuple(struct pcmcia_socket *s, unsigned int function,
 #define kfifo_out(a, b, c) __kfifo_get(*a, b, c)
 #define kfifo_len(a) __kfifo_len(*a)
 
+/**
+ * list_for_each_entry_continue_rcu - continue iteration over list of given type
+ * @pos:	the type * to use as a loop cursor.
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ *
+ * Continue to iterate over list of given type, continuing after
+ * the current position.
+ */
+#define list_for_each_entry_continue_rcu(pos, head, member) 		\
+	for (pos = list_entry_rcu(pos->member.next, typeof(*pos), member); \
+	     prefetch(pos->member.next), &pos->member != (head);	\
+	     pos = list_entry_rcu(pos->member.next, typeof(*pos), member))
+
 #endif /* (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,33)) */
 
 #endif /* LINUX_26_33_COMPAT_H */
-- 
1.7.0.4

Re: [PATCH 2/2] compat: backport list_for_each_entry_continue_rcu

[Luis R. Rodriguez]

On Wed, Sep 15, 2010 at 01:42:33PM -0700, Hauke Mehrtens wrote:
> This is needed for new driver carl9170.
> 
> Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

Thanks, applied and pushed out!

  Luis