[PATCH] md: Remove per-personality 'operational' and 'write_only' flags

raid1, raid5 and multipath maintain their own
'operational' flag.  This is equivalent to
   !rdev->faulty
and so isn't needed.
Similarly raid1 and raid1 maintain a "write_only" flag
that is equivalnt to
   !rdev->in_sync
so it isn't needed either.

As part of implementing this change, we introduce some extra
flag bit in raid5 that are meaningful only inside 'handle_stripe'.
Some of these replace the "action" array which recorded what
actions were required (and would be performed after the stripe
spinlock was released).  This has the advantage of reducing our
dependance on MD_SB_DISKS which personalities shouldn't need
to know about.

5 files changed, 20 insertions, 16 deletions

diff --git a/include/linux/raid/md.h b/include/linux/raid/md.h
index f2d44e5fcd0b..a9cca6e4da8f 100644
--- a/include/linux/raid/md.h
+++ b/include/linux/raid/md.h
@@ -77,8 +77,7 @@ extern void md_wakeup_thread(mdk_thread_t *thread);
 extern void md_interrupt_thread (mdk_thread_t *thread);
 extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
 extern void md_sync_acct(mdk_rdev_t *rdev, unsigned long nr_sectors);
-extern int md_error (mddev_t *mddev, mdk_rdev_t *rdev);
-extern int md_run_setup(void);
+extern void md_error (mddev_t *mddev, mdk_rdev_t *rdev);
 
 extern void md_print_devices (void);
 
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 721aa5d478d0..3c88b7882227 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -154,6 +154,16 @@ struct mdk_rdev_s
 	mdp_super_t	*sb;
 	unsigned long	sb_offset;
 
+	/* A device can be in one of three states based on two flags:
+	 * Not working:   faulty==1 in_sync==0
+	 * Fully working: faulty==0 in_sync==1
+	 * Working, but not
+	 * in sync with array
+	 *                faulty==0 in_sync==0
+	 *
+	 * It can never have faulty==1, in_sync==1
+	 * This reduces the burden of testing multiple flags in many cases
+	 */
 	int faulty;			/* if faulty do not issue IO requests */
 	int in_sync;			/* device is a full member of the array */
 
@@ -227,7 +237,10 @@ struct mdk_personality_s
 	int (*run)(mddev_t *mddev);
 	int (*stop)(mddev_t *mddev);
 	int (*status)(char *page, mddev_t *mddev);
-	int (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
+	/* error_handler must set ->faulty and clear ->in_sync
+	 * if appropriate, and should abort recovery if needed 
+	 */
+	void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
 	int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
 	int (*hot_remove_disk) (mddev_t *mddev, int number);
 	int (*spare_active) (mddev_t *mddev);
diff --git a/include/linux/raid/multipath.h b/include/linux/raid/multipath.h
index f95a77eb2982..50db7f3c8c57 100644
--- a/include/linux/raid/multipath.h
+++ b/include/linux/raid/multipath.h
@@ -6,11 +6,6 @@
 
 struct multipath_info {
 	mdk_rdev_t	*rdev;
-
-	/*
-	 * State bits:
-	 */
-	int		operational;
 };
 
 struct multipath_private_data {
diff --git a/include/linux/raid/raid1.h b/include/linux/raid/raid1.h
index 7e7cf996d865..7095e77cb63e 100644
--- a/include/linux/raid/raid1.h
+++ b/include/linux/raid/raid1.h
@@ -8,12 +8,6 @@ typedef struct mirror_info mirror_info_t;
 struct mirror_info {
 	mdk_rdev_t	*rdev;
 	sector_t	head_position;
-
-	/*
-	 * State bits:
-	 */
-	int		operational;
-	int		write_only;
 };
 
 typedef struct r1bio_s r1bio_t;
diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h
index 5e63e608b5eb..9d08de50d13a 100644
--- a/include/linux/raid/raid5.h
+++ b/include/linux/raid/raid5.h
@@ -148,6 +148,11 @@ struct stripe_head {
 #define	R5_UPTODATE	0	/* page contains current data */
 #define	R5_LOCKED	1	/* IO has been submitted on "req" */
 #define	R5_OVERWRITE	2	/* towrite covers whole page */
+/* and some that are internal to handle_stripe */
+#define	R5_Insync	3	/* rdev && rdev->in_sync at start */
+#define	R5_Wantread	4	/* want to schedule a read */
+#define	R5_Wantwrite	5
+#define	R5_Syncio	6	/* this io need to be accounted as resync io */
 
 /*
  * Write method
@@ -193,8 +198,6 @@ struct stripe_head {
 
 struct disk_info {
 	mdk_rdev_t	*rdev;
-	int		operational;
-	int		write_only;
 };
 
 struct raid5_private_data {