5 files changed, 73 insertions, 10 deletions

diff --git a/include/linux/raid/md.h b/include/linux/raid/md.h
index b6e0bcad84e1..66b44e5e0d6e 100644
--- a/include/linux/raid/md.h
+++ b/include/linux/raid/md.h
@@ -92,7 +92,10 @@ extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
 extern void md_super_wait(mddev_t *mddev);
 extern int sync_page_io(struct block_device *bdev, sector_t sector, int size,
                         struct page *page, int rw);
+extern void md_do_sync(mddev_t *mddev);
+extern void md_new_event(mddev_t *mddev);
 
+extern void md_update_sb(mddev_t * mddev);
 
 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
 
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 617b9506c760..e2df61f5b09a 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -132,6 +132,14 @@ struct mddev_s
 
         char                            uuid[16];
 
+        /* If the array is being reshaped, we need to record the
+         * new shape and an indication of where we are up to.
+         * This is written to the superblock.
+         * If reshape_position is MaxSector, then no reshape is happening (yet).
+         */
+        sector_t                        reshape_position;
+        int                             delta_disks, new_level, new_layout, new_chunk;
+
         struct mdk_thread_s             *thread;        /* management thread */
         struct mdk_thread_s             *sync_thread;   /* doing resync or reconstruct */
         sector_t                        curr_resync;    /* blocks scheduled */
@@ -143,6 +151,10 @@ struct mddev_s
         sector_t                        resync_mismatches; /* count of sectors where
                                                             * parity/replica mismatch found
                                                             */
+
+        /* allow user-space to request suspension of IO to regions of the array */
+        sector_t                        suspend_lo;
+        sector_t                        suspend_hi;
         /* if zero, use the system-wide default */
         int                             sync_speed_min;
         int                             sync_speed_max;
@@ -157,6 +169,9 @@ struct mddev_s
          * DONE:     thread is done and is waiting to be reaped
          * REQUEST:  user-space has requested a sync (used with SYNC)
          * CHECK:    user-space request for for check-only, no repair
+         * RESHAPE:  A reshape is happening
+         *
+         * If neither SYNC or RESHAPE are set, then it is a recovery.
          */
 #define MD_RECOVERY_RUNNING     0
 #define MD_RECOVERY_SYNC        1
@@ -166,10 +181,11 @@ struct mddev_s
 #define MD_RECOVERY_NEEDED      5
 #define MD_RECOVERY_REQUESTED   6
 #define MD_RECOVERY_CHECK       7
+#define MD_RECOVERY_RESHAPE     8
         unsigned long                   recovery;
 
         int                             in_sync;        /* know to not need resync */
-        struct semaphore                reconfig_sem;
+        struct mutex                    reconfig_mutex;
         atomic_t                        active;
 
         int                             changed;        /* true if we might need to reread partition info */
@@ -249,7 +265,8 @@ struct mdk_personality
         int (*spare_active) (mddev_t *mddev);
         sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
         int (*resize) (mddev_t *mddev, sector_t sectors);
-        int (*reshape) (mddev_t *mddev, int raid_disks);
+        int (*check_reshape) (mddev_t *mddev);
+        int (*start_reshape) (mddev_t *mddev);
         int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
         /* quiesce moves between quiescence states
          * 0 - fully active
diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h
index c100fa5d4bfa..774e1acfb8c4 100644
--- a/include/linux/raid/md_p.h
+++ b/include/linux/raid/md_p.h
@@ -102,6 +102,18 @@ typedef struct mdp_device_descriptor_s {
 #define MD_SB_ERRORS            1
 
 #define MD_SB_BITMAP_PRESENT    8 /* bitmap may be present nearby */
+
+/*
+ * Notes:
+ * - if an array is being reshaped (restriped) in order to change the
+ *   the number of active devices in the array, 'raid_disks' will be
+ *   the larger of the old and new numbers.  'delta_disks' will
+ *   be the "new - old".  So if +ve, raid_disks is the new value, and
+ *   "raid_disks-delta_disks" is the old.  If -ve, raid_disks is the
+ *   old value and "raid_disks+delta_disks" is the new (smaller) value.
+ */
+
+
 typedef struct mdp_superblock_s {
         /*
          * Constant generic information
@@ -146,7 +158,13 @@ typedef struct mdp_superblock_s {
         __u32 cp_events_hi;     /* 10 high-order of checkpoint update count   */
 #endif
         __u32 recovery_cp;      /* 11 recovery checkpoint sector count        */
-        __u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 12];
+        /* There are only valid for minor_version > 90 */
+        __u64 reshape_position; /* 12,13 next address in array-space for reshape */
+        __u32 new_level;        /* 14 new level we are reshaping to           */
+        __u32 delta_disks;      /* 15 change in number of raid_disks          */
+        __u32 new_layout;       /* 16 new layout                              */
+        __u32 new_chunk;        /* 17 new chunk size (bytes)                  */
+        __u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 18];
 
         /*
          * Personality information
@@ -207,7 +225,14 @@ struct mdp_superblock_1 {
                                  * NOTE: signed, so bitmap can be before superblock
                                  * only meaningful of feature_map[0] is set.
                                  */
-        __u8    pad1[128-100];  /* set to 0 when written */
+
+        /* These are only valid with feature bit '4' */
+        __u64   reshape_position;       /* next address in array-space for reshape */
+        __u32   new_level;      /* new level we are reshaping to                */
+        __u32   delta_disks;    /* change in number of raid_disks               */
+        __u32   new_layout;     /* new layout                                   */
+        __u32   new_chunk;      /* new chunk size (bytes)                       */
+        __u8    pad1[128-124];  /* set to 0 when written */
 
         /* constant this-device information - 64 bytes */
         __u64   data_offset;    /* sector start of data, often 0 */
@@ -240,8 +265,9 @@ struct mdp_superblock_1 {
 
 /* feature_map bits */
 #define MD_FEATURE_BITMAP_OFFSET        1
+#define MD_FEATURE_RESHAPE_ACTIVE       4
 
-#define MD_FEATURE_ALL                  1
+#define MD_FEATURE_ALL                  5
 
 #endif 
 
diff --git a/include/linux/raid/raid1.h b/include/linux/raid/raid1.h
index 9d5494aaac0f..3009c813d83d 100644
--- a/include/linux/raid/raid1.h
+++ b/include/linux/raid/raid1.h
@@ -130,6 +130,6 @@ struct r1bio_s {
  * with failure when last write completes (and all failed).
  * Record that bi_end_io was called with this flag...
  */
-#define R1BIO_Returned 4
+#define R1BIO_Returned 6
 
 #endif
diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h
index 394da8207b34..914af667044f 100644
--- a/include/linux/raid/raid5.h
+++ b/include/linux/raid/raid5.h
@@ -135,6 +135,7 @@ struct stripe_head {
         atomic_t                count;                  /* nr of active thread/requests */
         spinlock_t              lock;
         int                     bm_seq; /* sequence number for bitmap flushes */
+        int                     disks;                  /* disks in stripe */
         struct r5dev {
                 struct bio      req;
                 struct bio_vec  vec;
@@ -156,6 +157,7 @@ struct stripe_head {
 #define R5_ReadError    8       /* seen a read error here recently */
 #define R5_ReWrite      9       /* have tried to over-write the readerror */
 
+#define R5_Expanded     10      /* This block now has post-expand data */
 /*
  * Write method
  */
@@ -174,7 +176,9 @@ struct stripe_head {
 #define STRIPE_DELAYED          6
 #define STRIPE_DEGRADED         7
 #define STRIPE_BIT_DELAY        8
-
+#define STRIPE_EXPANDING        9
+#define STRIPE_EXPAND_SOURCE    10
+#define STRIPE_EXPAND_READY     11
 /*
  * Plugging:
  *
@@ -211,12 +215,24 @@ struct raid5_private_data {
         int                     raid_disks, working_disks, failed_disks;
         int                     max_nr_stripes;
 
+        /* used during an expand */
+        sector_t                expand_progress;        /* MaxSector when no expand happening */
+        sector_t                expand_lo; /* from here up to expand_progress it out-of-bounds
+                                            * as we haven't flushed the metadata yet
+                                            */
+        int                     previous_raid_disks;
+
         struct list_head        handle_list; /* stripes needing handling */
         struct list_head        delayed_list; /* stripes that have plugged requests */
         struct list_head        bitmap_list; /* stripes delaying awaiting bitmap update */
         atomic_t                preread_active_stripes; /* stripes with scheduled io */
 
-        char                    cache_name[20];
+        atomic_t                reshape_stripes; /* stripes with pending writes for reshape */
+        /* unfortunately we need two cache names as we temporarily have
+         * two caches.
+         */
+        int                     active_name;
+        char                    cache_name[2][20];
         kmem_cache_t            *slab_cache; /* for allocating stripes */
 
         int                     seq_flush, seq_write;
@@ -238,9 +254,10 @@ struct raid5_private_data {
         wait_queue_head_t       wait_for_overlap;
         int                     inactive_blocked;       /* release of inactive stripes blocked,
                                                          * waiting for 25% to be free
-                                                         */        
+                                                         */
+        int                     pool_size; /* number of disks in stripeheads in pool */
         spinlock_t              device_lock;
-        struct disk_info        disks[0];
+        struct disk_info        *disks;
 };
 
 typedef struct raid5_private_data raid5_conf_t;