Merge tag 'md-3.3' of git://neil.brown.name/md

md update for 3.3

Big change is new hot-replacement.
A slot in an array can hold 2 devices - one that
wants-replacement and one that is the replacement.
Once the replacement is built - either from the
original or (in the case of errors) from elsewhere,
the wants-replacement device will be removed.

* tag 'md-3.3' of git://neil.brown.name/md: (36 commits)
  md/raid1: Mark device want_replacement when we see a write error.
  md/raid1: If there is a spare and a want_replacement device, start replacement.
  md/raid1: recognise replacements when assembling arrays.
  md/raid1: handle activation of replacement device when recovery completes.
  md/raid1: Allow a failed replacement device to be removed.
  md/raid1: Allocate spare to store replacement devices and their bios.
  md/raid1:  Replace use of mddev->raid_disks with conf->raid_disks.
  md/raid10: If there is a spare and a want_replacement device, start replacement.
  md/raid10: recognise replacements when assembling array.
  md/raid10: Allow replacement device to be replace old drive.
  md/raid10: handle recovery of replacement devices.
  md/raid10:  Handle replacement devices during resync.
  md/raid10: writes should get directed to replacement as well as original.
  md/raid10: allow removal of failed replacement devices.
  md/raid10: preferentially read from replacement device if possible.
  md/raid10:  change read_balance to return an rdev
  md/raid10: prepare data structures for handling replacement.
  md/raid5: Mark device want_replacement when we see a write error.
  md/raid5: If there is a spare and a want_replacement device, start replacement.
  md/raid5: recognise replacements when assembling array.
  ...

2 files changed, 6 insertions, 3 deletions

diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h
index 9e65d9e2066..6f6df86f1ae 100644
--- a/include/linux/raid/md_p.h
+++ b/include/linux/raid/md_p.h
@@ -277,7 +277,10 @@ struct mdp_superblock_1 {
 					   */
 #define	MD_FEATURE_RESHAPE_ACTIVE	4
 #define	MD_FEATURE_BAD_BLOCKS		8 /* badblock list is not empty */
-
-#define	MD_FEATURE_ALL			(1|2|4|8)
+#define	MD_FEATURE_REPLACEMENT		16 /* This device is replacing an
+					    * active device with same 'role'.
+					    * 'recovery_offset' is also set.
+					    */
+#define	MD_FEATURE_ALL			(1|2|4|8|16)
 
 #endif 
diff --git a/include/linux/raid/pq.h b/include/linux/raid/pq.h
index 2b59cc82439..53272e9860a 100644
--- a/include/linux/raid/pq.h
+++ b/include/linux/raid/pq.h
@@ -132,7 +132,7 @@ void raid6_dual_recov(int disks, size_t bytes, int faila, int failb,
 						     PROT_READ|PROT_WRITE,   \
 						     MAP_PRIVATE|MAP_ANONYMOUS,\
 						     0, 0))
-# define free_pages(x, y)	munmap((void *)(x), (y)*PAGE_SIZE)
+# define free_pages(x, y)	munmap((void *)(x), PAGE_SIZE << (y))
 
 static inline void cpu_relax(void)
 {