X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=drivers%2Fmd%2Fraid1.h;h=b6bc7b1c589d8d5f7d725a575b42bbb4dd939f51;hb=fd01b88c75a718020ff77e7f560d33835e9b58de;hp=e0d676b4897498d22390600012da67e751b185ea;hpb=968e75fc13b6d582f42ce44172e13ba58157e11f;p=deliverable%2Flinux.git

diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index e0d676b48974..b6bc7b1c589d 100644
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -4,7 +4,7 @@
 typedef struct mirror_info mirror_info_t;
 
 struct mirror_info {
-	mdk_rdev_t	*rdev;
+	struct md_rdev	*rdev;
 	sector_t	head_position;
 };
 
@@ -17,7 +17,7 @@ struct mirror_info {
  */
 
 struct pool_info {
-	mddev_t *mddev;
+	struct mddev *mddev;
 	int	raid_disks;
 };
 
@@ -25,45 +25,70 @@ struct pool_info {
 typedef struct r1bio_s r1bio_t;
 
 struct r1_private_data_s {
-	mddev_t			*mddev;
+	struct mddev		*mddev;
 	mirror_info_t		*mirrors;
 	int			raid_disks;
+
+	/* When choose the best device for a read (read_balance())
+	 * we try to keep sequential reads one the same device
+	 * using 'last_used' and 'next_seq_sect'
+	 */
 	int			last_used;
 	sector_t		next_seq_sect;
+	/* During resync, read_balancing is only allowed on the part
+	 * of the array that has been resynced.  'next_resync' tells us
+	 * where that is.
+	 */
+	sector_t		next_resync;
+
 	spinlock_t		device_lock;
 
+	/* list of 'r1bio_t' that need to be processed by raid1d, whether
+	 * to retry a read, writeout a resync or recovery block, or
+	 * anything else.
+	 */
 	struct list_head	retry_list;
-	/* queue pending writes and submit them on unplug */
-	struct bio_list		pending_bio_list;
 
-	/* for use when syncing mirrors: */
+	/* queue pending writes to be submitted on unplug */
+	struct bio_list		pending_bio_list;
 
+	/* for use when syncing mirrors:
+	 * We don't allow both normal IO and resync/recovery IO at
+	 * the same time - resync/recovery can only happen when there
+	 * is no other IO.  So when either is active, the other has to wait.
+	 * See more details description in raid1.c near raise_barrier().
+	 */
+	wait_queue_head_t	wait_barrier;
 	spinlock_t		resync_lock;
 	int			nr_pending;
 	int			nr_waiting;
 	int			nr_queued;
 	int			barrier;
-	sector_t		next_resync;
-	int			fullsync;  /* set to 1 if a full sync is needed,
-					    * (fresh device added).
-					    * Cleared when a sync completes.
-					    */
-	int			recovery_disabled; /* when the same as
-						    * mddev->recovery_disabled
-						    * we don't allow recovery
-						    * to be attempted as we
-						    * expect a read error
-						    */
 
-	wait_queue_head_t	wait_barrier;
+	/* Set to 1 if a full sync is needed, (fresh device added).
+	 * Cleared when a sync completes.
+	 */
+	int			fullsync;
 
-	struct pool_info	*poolinfo;
+	/* When the same as mddev->recovery_disabled we don't allow
+	 * recovery to be attempted as we expect a read error.
+	 */
+	int			recovery_disabled;
 
-	struct page		*tmppage;
 
+	/* poolinfo contains information about the content of the
+	 * mempools - it changes when the array grows or shrinks
+	 */
+	struct pool_info	*poolinfo;
 	mempool_t *r1bio_pool;
 	mempool_t *r1buf_pool;
 
+	/* temporary buffer to synchronous IO when attempting to repair
+	 * a read error.
+	 */
+	struct page		*tmppage;
+
+
 	/* When taking over an array from a different personality, we store
 	 * the new thread here until we fully activate the array.
 	 */
@@ -89,7 +114,7 @@ struct r1bio_s {
 	sector_t		sector;
 	int			sectors;
 	unsigned long		state;
-	mddev_t			*mddev;
+	struct mddev		*mddev;
 	/*
 	 * original bio going to /dev/mdx
 	 */
@@ -148,6 +173,6 @@ struct r1bio_s {
 #define	R1BIO_MadeGood 7
 #define	R1BIO_WriteError 8
 
-extern int md_raid1_congested(mddev_t *mddev, int bits);
+extern int md_raid1_congested(struct mddev *mddev, int bits);
 
 #endif