static inline dev_info_t *which_dev(mddev_t *mddev, sector_t sector)
{
int lo, mid, hi;
- linear_conf_t *conf = mddev->private;
+ linear_conf_t *conf;
lo = 0;
hi = mddev->raid_disks - 1;
+ conf = rcu_dereference(mddev->private);
/*
* Binary Search
unsigned long maxsectors, bio_sectors = bvm->bi_size >> 9;
sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
+ rcu_read_lock();
dev0 = which_dev(mddev, sector);
maxsectors = dev0->end_sector - sector;
+ rcu_read_unlock();
if (maxsectors < bio_sectors)
maxsectors = 0;
static void linear_unplug(struct request_queue *q)
{
mddev_t *mddev = q->queuedata;
- linear_conf_t *conf = mddev->private;
+ linear_conf_t *conf;
int i;
+ rcu_read_lock();
+ conf = rcu_dereference(mddev->private);
+
for (i=0; i < mddev->raid_disks; i++) {
struct request_queue *r_queue = bdev_get_queue(conf->disks[i].rdev->bdev);
blk_unplug(r_queue);
}
+ rcu_read_unlock();
}
static int linear_congested(void *data, int bits)
{
mddev_t *mddev = data;
- linear_conf_t *conf = mddev->private;
+ linear_conf_t *conf;
int i, ret = 0;
+ rcu_read_lock();
+ conf = rcu_dereference(mddev->private);
+
for (i = 0; i < mddev->raid_disks && !ret ; i++) {
struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev);
ret |= bdi_congested(&q->backing_dev_info, bits);
}
+
+ rcu_read_unlock();
return ret;
}
static sector_t linear_size(mddev_t *mddev, sector_t sectors, int raid_disks)
{
- linear_conf_t *conf = mddev->private;
+ linear_conf_t *conf;
+ sector_t array_sectors;
+ rcu_read_lock();
+ conf = rcu_dereference(mddev->private);
WARN_ONCE(sectors || raid_disks,
"%s does not support generic reshape\n", __func__);
+ array_sectors = conf->array_sectors;
+ rcu_read_unlock();
- return conf->array_sectors;
+ return array_sectors;
}
static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks)
list_for_each_entry(rdev, &mddev->disks, same_set) {
int j = rdev->raid_disk;
dev_info_t *disk = conf->disks + j;
+ sector_t sectors;
if (j < 0 || j >= raid_disks || disk->rdev) {
printk("linear: disk numbering problem. Aborting!\n");
}
disk->rdev = rdev;
+ if (mddev->chunk_sectors) {
+ sectors = rdev->sectors;
+ sector_div(sectors, mddev->chunk_sectors);
+ rdev->sectors = sectors * mddev->chunk_sectors;
+ }
blk_queue_stack_limits(mddev->queue,
rdev->bdev->bd_disk->queue);
{
linear_conf_t *conf;
+ if (md_check_no_bitmap(mddev))
+ return -EINVAL;
mddev->queue->queue_lock = &mddev->queue->__queue_lock;
conf = linear_conf(mddev, mddev->raid_disks);
return 0;
}
+static void free_conf(struct rcu_head *head)
+{
+ linear_conf_t *conf = container_of(head, linear_conf_t, rcu);
+ kfree(conf);
+}
+
static int linear_add(mddev_t *mddev, mdk_rdev_t *rdev)
{
/* Adding a drive to a linear array allows the array to grow.
* The current one is never freed until the array is stopped.
* This avoids races.
*/
- linear_conf_t *newconf;
+ linear_conf_t *newconf, *oldconf;
if (rdev->saved_raid_disk != mddev->raid_disks)
return -EINVAL;
if (!newconf)
return -ENOMEM;
- newconf->prev = mddev->private;
- mddev->private = newconf;
+ oldconf = rcu_dereference(mddev->private);
mddev->raid_disks++;
+ rcu_assign_pointer(mddev->private, newconf);
md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
set_capacity(mddev->gendisk, mddev->array_sectors);
+ call_rcu(&oldconf->rcu, free_conf);
return 0;
}
static int linear_stop (mddev_t *mddev)
{
linear_conf_t *conf = mddev->private;
-
+
+ /*
+ * We do not require rcu protection here since
+ * we hold reconfig_mutex for both linear_add and
+ * linear_stop, so they cannot race.
+ * We should make sure any old 'conf's are properly
+ * freed though.
+ */
+ rcu_barrier();
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
- do {
- linear_conf_t *t = conf->prev;
- kfree(conf);
- conf = t;
- } while (conf);
+ kfree(conf);
return 0;
}
bio_sectors(bio));
part_stat_unlock();
+ rcu_read_lock();
tmp_dev = which_dev(mddev, bio->bi_sector);
start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
+
if (unlikely(bio->bi_sector >= (tmp_dev->end_sector)
|| (bio->bi_sector < start_sector))) {
char b[BDEVNAME_SIZE];
bdevname(tmp_dev->rdev->bdev, b),
(unsigned long long)tmp_dev->rdev->sectors,
(unsigned long long)start_sector);
+ rcu_read_unlock();
bio_io_error(bio);
return 0;
}
* split it.
*/
struct bio_pair *bp;
+ sector_t end_sector = tmp_dev->end_sector;
+
+ rcu_read_unlock();
- bp = bio_split(bio,
- tmp_dev->end_sector - bio->bi_sector);
+ bp = bio_split(bio, end_sector - bio->bi_sector);
if (linear_make_request(q, &bp->bio1))
generic_make_request(&bp->bio1);
bio->bi_bdev = tmp_dev->rdev->bdev;
bio->bi_sector = bio->bi_sector - start_sector
+ tmp_dev->rdev->data_offset;
+ rcu_read_unlock();
return 1;
}