[PATCH] md: provide proper rcu_dereference / rcu_assign_pointer annotations in md

[deliverable/linux.git] / drivers / md / raid10.c

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index bbe40e9cf9236cd843a7a17a28f92019d20b2a2c..26114f40bde6784e503ed47c862a4a9fa6c5b5e4 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -496,6 +496,7 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
        int disk, slot, nslot;
        const int sectors = r10_bio->sectors;
        sector_t new_distance, current_distance;
+       mdk_rdev_t *rdev;
 
        raid10_find_phys(conf, r10_bio);
        rcu_read_lock();
@@ -510,8 +511,8 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
                slot = 0;
                disk = r10_bio->devs[slot].devnum;
 
-               while (!conf->mirrors[disk].rdev ||
-                      !conf->mirrors[disk].rdev->in_sync) {
+               while ((rdev = rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
+                      !rdev->in_sync) {
                        slot++;
                        if (slot == conf->copies) {
                                slot = 0;
@@ -527,8 +528,8 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
        /* make sure the disk is operational */
        slot = 0;
        disk = r10_bio->devs[slot].devnum;
-       while (!conf->mirrors[disk].rdev ||
-              !conf->mirrors[disk].rdev->in_sync) {
+       while ((rdev=rcu_dereference(conf->mirrors[disk].rdev)) == NULL ||
+              !rdev->in_sync) {
                slot ++;
                if (slot == conf->copies) {
                        disk = -1;
@@ -547,11 +548,11 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
                int ndisk = r10_bio->devs[nslot].devnum;
 
 
-               if (!conf->mirrors[ndisk].rdev ||
-                   !conf->mirrors[ndisk].rdev->in_sync)
+               if ((rdev=rcu_dereference(conf->mirrors[ndisk].rdev)) == NULL ||
+                   !rdev->in_sync)
                        continue;
 
-               if (!atomic_read(&conf->mirrors[ndisk].rdev->nr_pending)) {
+               if (!atomic_read(&rdev->nr_pending)) {
                        disk = ndisk;
                        slot = nslot;
                        break;
@@ -569,7 +570,7 @@ rb_out:
        r10_bio->read_slot = slot;
 /*     conf->next_seq_sect = this_sector + sectors;*/
 
-       if (disk >= 0 && conf->mirrors[disk].rdev)
+       if (disk >= 0 && (rdev=rcu_dereference(conf->mirrors[disk].rdev))!= NULL)
                atomic_inc(&conf->mirrors[disk].rdev->nr_pending);
        rcu_read_unlock();
 
@@ -583,7 +584,7 @@ static void unplug_slaves(mddev_t *mddev)
 
        rcu_read_lock();
        for (i=0; i<mddev->raid_disks; i++) {
-               mdk_rdev_t *rdev = conf->mirrors[i].rdev;
+               mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
                if (rdev && !rdev->faulty && atomic_read(&rdev->nr_pending)) {
                        request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
 
@@ -614,7 +615,7 @@ static int raid10_issue_flush(request_queue_t *q, struct gendisk *disk,
 
        rcu_read_lock();
        for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-               mdk_rdev_t *rdev = conf->mirrors[i].rdev;
+               mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
                if (rdev && !rdev->faulty) {
                        struct block_device *bdev = rdev->bdev;
                        request_queue_t *r_queue = bdev_get_queue(bdev);
@@ -768,9 +769,10 @@ static int make_request(request_queue_t *q, struct bio * bio)
        rcu_read_lock();
        for (i = 0;  i < conf->copies; i++) {
                int d = r10_bio->devs[i].devnum;
-               if (conf->mirrors[d].rdev &&
-                   !conf->mirrors[d].rdev->faulty) {
-                       atomic_inc(&conf->mirrors[d].rdev->nr_pending);
+               mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev);
+               if (rdev &&
+                   !rdev->faulty) {
+                       atomic_inc(&rdev->nr_pending);
                        r10_bio->devs[i].bio = bio;
                } else
                        r10_bio->devs[i].bio = NULL;
@@ -980,7 +982,7 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
                        p->head_position = 0;
                        rdev->raid_disk = mirror;
                        found = 1;
-                       p->rdev = rdev;
+                       rcu_assign_pointer(p->rdev, rdev);
                        break;
                }