Merge tag 'md-3.5' of git://neil.brown.name/md

Pull md updates from NeilBrown:
 "It's been a busy cycle for md - lots of fun stuff here..  if you like
  this kind of thing :-)

  Main features:
   - RAID10 arrays can be reshaped - adding and removing devices and
     changing chunks (not 'far' array though)
   - allow RAID5 arrays to be reshaped with a backup file (not tested
     yet, but the priciple works fine for RAID10).
   - arrays can be reshaped while a bitmap is present - you no longer
     need to remove it first
   - SSSE3 support for RAID6 syndrome calculations

  and of course a number of minor fixes etc."

* tag 'md-3.5' of git://neil.brown.name/md: (56 commits)
  md/bitmap: record the space available for the bitmap in the superblock.
  md/raid10: Remove extras after reshape to smaller number of devices.
  md/raid5: improve removal of extra devices after reshape.
  md: check the return of mddev_find()
  MD RAID1: Further conditionalize 'fullsync'
  DM RAID: Use md_error() in place of simply setting Faulty bit
  DM RAID: Record and handle missing devices
  DM RAID: Set recovery flags on resume
  md/raid5: Allow reshape while a bitmap is present.
  md/raid10: resize bitmap when required during reshape.
  md: allow array to be resized while bitmap is present.
  md/bitmap: make sure reshape request are reflected in superblock.
  md/bitmap: add bitmap_resize function to allow bitmap resizing.
  md/bitmap: use DIV_ROUND_UP instead of open-code
  md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap'
  md/bitmap: make bitmap bitops atomic.
  md/bitmap: make _page_attr bitops atomic.
  md/bitmap: merge bitmap_file_unmap and bitmap_file_put.
  md/bitmap: remove async freeing of bitmap file.
  md/bitmap: convert some spin_lock_irqsave to spin_lock_irq
  ...

1 files changed, 23 insertions, 11 deletions

diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h
index 7c615613c381..135b1b0a1554 100644
--- a/drivers/md/raid10.h
+++ b/drivers/md/raid10.h
@@ -14,32 +14,38 @@ struct mirror_info {
 struct r10conf {
 	struct mddev		*mddev;
 	struct mirror_info	*mirrors;
-	int			raid_disks;
+	struct mirror_info	*mirrors_new, *mirrors_old;
 	spinlock_t		device_lock;
 
 	/* geometry */
-	int			near_copies;  /* number of copies laid out
+	struct geom {
+		int		raid_disks;
+		int		near_copies;  /* number of copies laid out
 					       * raid0 style */
-	int 			far_copies;   /* number of copies laid out
+		int		far_copies;   /* number of copies laid out
 					       * at large strides across drives
 					       */
-	int			far_offset;   /* far_copies are offset by 1
+		int		far_offset;   /* far_copies are offset by 1
 					       * stripe instead of many
 					       */
-	int			copies;	      /* near_copies * far_copies.
-					       * must be <= raid_disks
-					       */
-	sector_t		stride;	      /* distance between far copies.
+		sector_t	stride;	      /* distance between far copies.
 					       * This is size / far_copies unless
 					       * far_offset, in which case it is
 					       * 1 stripe.
 					       */
+		int		chunk_shift; /* shift from chunks to sectors */
+		sector_t	chunk_mask;
+	} prev, geo;
+	int			copies;	      /* near_copies * far_copies.
+					       * must be <= raid_disks
+					       */
 
 	sector_t		dev_sectors;  /* temp copy of
 					       * mddev->dev_sectors */
-
-	int			chunk_shift; /* shift from chunks to sectors */
-	sector_t		chunk_mask;
+	sector_t		reshape_progress;
+	sector_t		reshape_safe;
+	unsigned long		reshape_checkpoint;
+	sector_t		offset_diff;
 
 	struct list_head	retry_list;
 	/* queue pending writes and submit them on unplug */
@@ -136,6 +142,7 @@ enum r10bio_state {
 	R10BIO_Uptodate,
 	R10BIO_IsSync,
 	R10BIO_IsRecover,
+	R10BIO_IsReshape,
 	R10BIO_Degraded,
 /* Set ReadError on bios that experience a read error
  * so that raid10d knows what to do with them.
@@ -146,5 +153,10 @@ enum r10bio_state {
  */
 	R10BIO_MadeGood,
 	R10BIO_WriteError,
+/* During a reshape we might be performing IO on the
+ * 'previous' part of the array, in which case this
+ * flag is set
+ */
+	R10BIO_Previous,
 };
 #endif