md: use list_for_each_entry macro directly
[safe/jmp/linux-2.6] / drivers / md / raid1.c
index ae7c152..c165b1e 100644 (file)
@@ -32,6 +32,7 @@
  */
 
 #include "dm-bio-list.h"
+#include <linux/delay.h>
 #include <linux/raid/raid1.h>
 #include <linux/raid/bitmap.h>
 
@@ -592,6 +593,37 @@ static int raid1_congested(void *data, int bits)
 }
 
 
+static int flush_pending_writes(conf_t *conf)
+{
+       /* Any writes that have been queued but are awaiting
+        * bitmap updates get flushed here.
+        * We return 1 if any requests were actually submitted.
+        */
+       int rv = 0;
+
+       spin_lock_irq(&conf->device_lock);
+
+       if (conf->pending_bio_list.head) {
+               struct bio *bio;
+               bio = bio_list_get(&conf->pending_bio_list);
+               blk_remove_plug(conf->mddev->queue);
+               spin_unlock_irq(&conf->device_lock);
+               /* flush any pending bitmap writes to
+                * disk before proceeding w/ I/O */
+               bitmap_unplug(conf->mddev->bitmap);
+
+               while (bio) { /* submit pending writes */
+                       struct bio *next = bio->bi_next;
+                       bio->bi_next = NULL;
+                       generic_make_request(bio);
+                       bio = next;
+               }
+               rv = 1;
+       } else
+               spin_unlock_irq(&conf->device_lock);
+       return rv;
+}
+
 /* Barriers....
  * Sometimes we need to suspend IO while we do something else,
  * either some resync/recovery, or reconfigure the array.
@@ -673,15 +705,23 @@ static void freeze_array(conf_t *conf)
        /* stop syncio and normal IO and wait for everything to
         * go quite.
         * We increment barrier and nr_waiting, and then
-        * wait until barrier+nr_pending match nr_queued+2
+        * wait until nr_pending match nr_queued+1
+        * This is called in the context of one normal IO request
+        * that has failed. Thus any sync request that might be pending
+        * will be blocked by nr_pending, and we need to wait for
+        * pending IO requests to complete or be queued for re-try.
+        * Thus the number queued (nr_queued) plus this request (1)
+        * must match the number of pending IOs (nr_pending) before
+        * we continue.
         */
        spin_lock_irq(&conf->resync_lock);
        conf->barrier++;
        conf->nr_waiting++;
        wait_event_lock_irq(conf->wait_barrier,
-                           conf->barrier+conf->nr_pending == conf->nr_queued+2,
+                           conf->nr_pending == conf->nr_queued+1,
                            conf->resync_lock,
-                           raid1_unplug(conf->mddev->queue));
+                           ({ flush_pending_writes(conf);
+                              raid1_unplug(conf->mddev->queue); }));
        spin_unlock_irq(&conf->resync_lock);
 }
 static void unfreeze_array(conf_t *conf)
@@ -734,14 +774,14 @@ static int make_request(struct request_queue *q, struct bio * bio)
        r1bio_t *r1_bio;
        struct bio *read_bio;
        int i, targets = 0, disks;
-       mdk_rdev_t *rdev;
-       struct bitmap *bitmap = mddev->bitmap;
+       struct bitmap *bitmap;
        unsigned long flags;
        struct bio_list bl;
        struct page **behind_pages = NULL;
        const int rw = bio_data_dir(bio);
        const int do_sync = bio_sync(bio);
-       int do_barriers;
+       int cpu, do_barriers;
+       mdk_rdev_t *blocked_rdev;
 
        /*
         * Register the new request and wait if the reconstruction
@@ -763,8 +803,13 @@ static int make_request(struct request_queue *q, struct bio * bio)
 
        wait_barrier(conf);
 
-       disk_stat_inc(mddev->gendisk, ios[rw]);
-       disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
+       bitmap = mddev->bitmap;
+
+       cpu = part_stat_lock();
+       part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+       part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
+                     bio_sectors(bio));
+       part_stat_unlock();
 
        /*
         * make_request() can abort the operation when READA is being
@@ -823,10 +868,17 @@ static int make_request(struct request_queue *q, struct bio * bio)
        first = 0;
        }
 #endif
+ retry_write:
+       blocked_rdev = NULL;
        rcu_read_lock();
        for (i = 0;  i < disks; i++) {
-               if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL &&
-                   !test_bit(Faulty, &rdev->flags)) {
+               mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+               if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+                       atomic_inc(&rdev->nr_pending);
+                       blocked_rdev = rdev;
+                       break;
+               }
+               if (rdev && !test_bit(Faulty, &rdev->flags)) {
                        atomic_inc(&rdev->nr_pending);
                        if (test_bit(Faulty, &rdev->flags)) {
                                rdev_dec_pending(rdev, mddev);
@@ -839,6 +891,20 @@ static int make_request(struct request_queue *q, struct bio * bio)
        }
        rcu_read_unlock();
 
+       if (unlikely(blocked_rdev)) {
+               /* Wait for this device to become unblocked */
+               int j;
+
+               for (j = 0; j < i; j++)
+                       if (r1_bio->bios[j])
+                               rdev_dec_pending(conf->mirrors[j].rdev, mddev);
+
+               allow_barrier(conf);
+               md_wait_for_blocked_rdev(blocked_rdev, mddev);
+               wait_barrier(conf);
+               goto retry_write;
+       }
+
        BUG_ON(targets == 0); /* we never fail the last device */
 
        if (targets < conf->raid_disks) {
@@ -907,6 +973,9 @@ static int make_request(struct request_queue *q, struct bio * bio)
        blk_plug_device(mddev->queue);
        spin_unlock_irqrestore(&conf->device_lock, flags);
 
+       /* In case raid1d snuck into freeze_array */
+       wake_up(&conf->wait_barrier);
+
        if (do_sync)
                md_wakeup_thread(mddev->thread);
 #if 0
@@ -962,12 +1031,12 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
                /*
                 * if recovery is running, make sure it aborts.
                 */
-               set_bit(MD_RECOVERY_ERR, &mddev->recovery);
+               set_bit(MD_RECOVERY_INTR, &mddev->recovery);
        } else
                set_bit(Faulty, &rdev->flags);
        set_bit(MD_CHANGE_DEVS, &mddev->flags);
-       printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
-               "       Operation continuing on %d devices\n",
+       printk(KERN_ALERT "raid1: Disk failure on %s, disabling device.\n"
+               "raid1: Operation continuing on %d devices.\n",
                bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
 }
 
@@ -1035,11 +1104,16 @@ static int raid1_spare_active(mddev_t *mddev)
 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 {
        conf_t *conf = mddev->private;
-       int found = 0;
+       int err = -EEXIST;
        int mirror = 0;
        mirror_info_t *p;
+       int first = 0;
+       int last = mddev->raid_disks - 1;
+
+       if (rdev->raid_disk >= 0)
+               first = last = rdev->raid_disk;
 
-       for (mirror=0; mirror < mddev->raid_disks; mirror++)
+       for (mirror = first; mirror <= last; mirror++)
                if ( !(p=conf->mirrors+mirror)->rdev) {
 
                        blk_queue_stack_limits(mddev->queue,
@@ -1054,7 +1128,7 @@ static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
 
                        p->head_position = 0;
                        rdev->raid_disk = mirror;
-                       found = 1;
+                       err = 0;
                        /* As all devices are equivalent, we don't need a full recovery
                         * if this was recently any drive of the array
                         */
@@ -1065,7 +1139,7 @@ static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
                }
 
        print_conf(conf);
-       return found;
+       return err;
 }
 
 static int raid1_remove_disk(mddev_t *mddev, int number)
@@ -1083,6 +1157,14 @@ static int raid1_remove_disk(mddev_t *mddev, int number)
                        err = -EBUSY;
                        goto abort;
                }
+               /* Only remove non-faulty devices is recovery
+                * is not possible.
+                */
+               if (!test_bit(Faulty, &rdev->flags) &&
+                   mddev->degraded < conf->raid_disks) {
+                       err = -EBUSY;
+                       goto abort;
+               }
                p->rdev = NULL;
                synchronize_rcu();
                if (atomic_read(&rdev->nr_pending)) {
@@ -1219,23 +1301,31 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
                                        rdev_dec_pending(conf->mirrors[i].rdev, mddev);
                                } else {
                                        /* fixup the bio for reuse */
+                                       int size;
                                        sbio->bi_vcnt = vcnt;
                                        sbio->bi_size = r1_bio->sectors << 9;
                                        sbio->bi_idx = 0;
                                        sbio->bi_phys_segments = 0;
-                                       sbio->bi_hw_segments = 0;
-                                       sbio->bi_hw_front_size = 0;
-                                       sbio->bi_hw_back_size = 0;
                                        sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
                                        sbio->bi_flags |= 1 << BIO_UPTODATE;
                                        sbio->bi_next = NULL;
                                        sbio->bi_sector = r1_bio->sector +
                                                conf->mirrors[i].rdev->data_offset;
                                        sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
-                                       for (j = 0; j < vcnt ; j++)
-                                               memcpy(page_address(sbio->bi_io_vec[j].bv_page),
+                                       size = sbio->bi_size;
+                                       for (j = 0; j < vcnt ; j++) {
+                                               struct bio_vec *bi;
+                                               bi = &sbio->bi_io_vec[j];
+                                               bi->bv_offset = 0;
+                                               if (size > PAGE_SIZE)
+                                                       bi->bv_len = PAGE_SIZE;
+                                               else
+                                                       bi->bv_len = size;
+                                               size -= PAGE_SIZE;
+                                               memcpy(page_address(bi->bv_page),
                                                       page_address(pbio->bi_io_vec[j].bv_page),
                                                       PAGE_SIZE);
+                                       }
 
                                }
                        }
@@ -1473,28 +1563,14 @@ static void raid1d(mddev_t *mddev)
        
        for (;;) {
                char b[BDEVNAME_SIZE];
-               spin_lock_irqsave(&conf->device_lock, flags);
-
-               if (conf->pending_bio_list.head) {
-                       bio = bio_list_get(&conf->pending_bio_list);
-                       blk_remove_plug(mddev->queue);
-                       spin_unlock_irqrestore(&conf->device_lock, flags);
-                       /* flush any pending bitmap writes to disk before proceeding w/ I/O */
-                       bitmap_unplug(mddev->bitmap);
-
-                       while (bio) { /* submit pending writes */
-                               struct bio *next = bio->bi_next;
-                               bio->bi_next = NULL;
-                               generic_make_request(bio);
-                               bio = next;
-                       }
-                       unplug = 1;
 
-                       continue;
-               }
+               unplug += flush_pending_writes(conf);
 
-               if (list_empty(head))
+               spin_lock_irqsave(&conf->device_lock, flags);
+               if (list_empty(head)) {
+                       spin_unlock_irqrestore(&conf->device_lock, flags);
                        break;
+               }
                r1_bio = list_entry(head->prev, r1bio_t, retry_list);
                list_del(head->prev);
                conf->nr_queued--;
@@ -1590,7 +1666,6 @@ static void raid1d(mddev_t *mddev)
                        }
                }
        }
-       spin_unlock_irqrestore(&conf->device_lock, flags);
        if (unplug)
                unplug_slaves(mddev);
 }
@@ -1716,7 +1791,6 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                bio->bi_vcnt = 0;
                bio->bi_idx = 0;
                bio->bi_phys_segments = 0;
-               bio->bi_hw_segments = 0;
                bio->bi_size = 0;
                bio->bi_end_io = NULL;
                bio->bi_private = NULL;
@@ -1845,7 +1919,6 @@ static int run(mddev_t *mddev)
        int i, j, disk_idx;
        mirror_info_t *disk;
        mdk_rdev_t *rdev;
-       struct list_head *tmp;
 
        if (mddev->level != 1) {
                printk("raid1: %s: raid level not set to mirroring (%d)\n",
@@ -1887,7 +1960,10 @@ static int run(mddev_t *mddev)
        if (!conf->r1bio_pool)
                goto out_no_mem;
 
-       ITERATE_RDEV(mddev, rdev, tmp) {
+       spin_lock_init(&conf->device_lock);
+       mddev->queue->queue_lock = &conf->device_lock;
+
+       list_for_each_entry(rdev, &mddev->disks, same_set) {
                disk_idx = rdev->raid_disk;
                if (disk_idx >= mddev->raid_disks
                    || disk_idx < 0)
@@ -1910,7 +1986,6 @@ static int run(mddev_t *mddev)
        }
        conf->raid_disks = mddev->raid_disks;
        conf->mddev = mddev;
-       spin_lock_init(&conf->device_lock);
        INIT_LIST_HEAD(&conf->retry_list);
 
        spin_lock_init(&conf->resync_lock);
@@ -1967,7 +2042,7 @@ static int run(mddev_t *mddev)
        /*
         * Ok, everything is just fine now
         */
-       mddev->array_size = mddev->size;
+       mddev->array_sectors = mddev->size * 2;
 
        mddev->queue->unplug_fn = raid1_unplug;
        mddev->queue->backing_dev_info.congested_fn = raid1_congested;
@@ -2029,14 +2104,15 @@ static int raid1_resize(mddev_t *mddev, sector_t sectors)
         * any io in the removed space completes, but it hardly seems
         * worth it.
         */
-       mddev->array_size = sectors>>1;
-       set_capacity(mddev->gendisk, mddev->array_size << 1);
+       mddev->array_sectors = sectors;
+       set_capacity(mddev->gendisk, mddev->array_sectors);
        mddev->changed = 1;
-       if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
+       if (mddev->array_sectors / 2 > mddev->size &&
+           mddev->recovery_cp == MaxSector) {
                mddev->recovery_cp = mddev->size << 1;
                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
        }
-       mddev->size = mddev->array_size;
+       mddev->size = mddev->array_sectors / 2;
        mddev->resync_max_sectors = sectors;
        return 0;
 }
@@ -2060,7 +2136,7 @@ static int raid1_reshape(mddev_t *mddev)
        conf_t *conf = mddev_to_conf(mddev);
        int cnt, raid_disks;
        unsigned long flags;
-       int d, d2;
+       int d, d2, err;
 
        /* Cannot change chunk_size, layout, or level */
        if (mddev->chunk_size != mddev->new_chunk ||
@@ -2072,7 +2148,9 @@ static int raid1_reshape(mddev_t *mddev)
                return -EINVAL;
        }
 
-       md_allow_write(mddev);
+       err = md_allow_write(mddev);
+       if (err)
+               return err;
 
        raid_disks = mddev->raid_disks + mddev->delta_disks;