[PATCH 1/1] UBUNTU: ubuntu: Add dm-raid4-5 driver -- port to 2.6.28

[Andy Whitcroft]

Bug: #309378

The dm-raid4-5 driver was disabled as it did not cleanly compile when
rebased to 2.6.28.  This was due to two errors:

1) the removal of {set,clear}_page_locked() as the atomic versions were
   no longer used elsewhere in the kernel, and
2) the array_too_big() function was renamed to dm_array_too_big() to
   allow it to be exported.

As raid is a highly critical subsystem I have taken the safest possible
approach and assumed that RAID does require the atomic flag modifiers.
This patch therefore reinstates {set,clear}_page_locked() and moves the
code to using the new dm_array_too_big() interface.  Finally it reenabled
the raid support.

I have deliberatly re-introduced {set,clear}_page_locked() into the
original headers next to their corresponding unlocked form such that
should those change again we will conflict and detect the change.

Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 include/linux/pagemap.h        |    8 ++++++++
 ubuntu/dm-raid4-5/Makefile     |    2 +-
 ubuntu/dm-raid4-5/dm-raid4-5.c |    2 +-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 709742b..f09e3b2 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -303,11 +303,19 @@ static inline void __set_page_locked(struct page *page)
 {
 	__set_bit(PG_locked, &page->flags);
 }
+static inline void set_page_locked(struct page *page)
+{
+	set_bit(PG_locked, &page->flags);
+}
 
 static inline void __clear_page_locked(struct page *page)
 {
 	__clear_bit(PG_locked, &page->flags);
 }
+static inline void clear_page_locked(struct page *page)
+{
+	clear_bit(PG_locked, &page->flags);
+}
 
 static inline int trylock_page(struct page *page)
 {
diff --git a/ubuntu/dm-raid4-5/Makefile b/ubuntu/dm-raid4-5/Makefile
index b33ce8d..3a7e2fb 100644
--- a/ubuntu/dm-raid4-5/Makefile
+++ b/ubuntu/dm-raid4-5/Makefile
@@ -1,3 +1,3 @@
 EXTRA_CFLAGS += -I$(srctree)/drivers/md
 
-#obj-$(CONFIG_DM_RAID45) += dm-raid4-5.o dm-mem-cache.o dm-region_hash.o dm-message.o
+obj-$(CONFIG_DM_RAID45) += dm-raid4-5.o dm-mem-cache.o dm-region_hash.o dm-message.o
diff --git a/ubuntu/dm-raid4-5/dm-raid4-5.c b/ubuntu/dm-raid4-5/dm-raid4-5.c
index 156a219..73dc5e2 100644
--- a/ubuntu/dm-raid4-5/dm-raid4-5.c
+++ b/ubuntu/dm-raid4-5/dm-raid4-5.c
@@ -3296,7 +3296,7 @@ context_alloc(struct raid_set **raid_set, struct raid_type *raid_type,
 
 	/* Size and allocate the RAID set structure. */
 	len = sizeof(*rs->data) + sizeof(*rs->dev);
-	if (array_too_big(sizeof(*rs), len, raid_devs))
+	if (dm_array_too_big(sizeof(*rs), len, raid_devs))
 		goto bad_array;
 
 	len = sizeof(*rs) + raid_devs * len;
-- 
1.6.0.4.911.gc990