md: rcu_read_lock() walk of mddev->disks in md_do_sync()

[safe/jmp/linux-2.6] / drivers / md / dm-stripe.c

diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index a2d068d..e0efc1a 100644 (file)
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -167,6 +167,7 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
        sc->stripes = stripes;
        sc->stripe_width = width;
        ti->split_io = chunk_size;
+       ti->num_flush_requests = stripes;
 
        sc->chunk_mask = ((sector_t) chunk_size) - 1;
        for (sc->chunk_shift = 0; chunk_size; sc->chunk_shift++)
@@ -211,10 +212,18 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
                      union map_info *map_context)
 {
        struct stripe_c *sc = (struct stripe_c *) ti->private;
+       sector_t offset, chunk;
+       uint32_t stripe;
 
-       sector_t offset = bio->bi_sector - ti->begin;
-       sector_t chunk = offset >> sc->chunk_shift;
-       uint32_t stripe = sector_div(chunk, sc->stripes);
+       if (unlikely(bio_empty_barrier(bio))) {
+               BUG_ON(map_context->flush_request >= sc->stripes);
+               bio->bi_bdev = sc->stripe[map_context->flush_request].dev->bdev;
+               return DM_MAPIO_REMAPPED;
+       }
+
+       offset = bio->bi_sector - ti->begin;
+       chunk = offset >> sc->chunk_shift;
+       stripe = sector_div(chunk, sc->stripes);
 
        bio->bi_bdev = sc->stripe[stripe].dev->bdev;
        bio->bi_sector = sc->stripe[stripe].physical_start +
@@ -276,7 +285,7 @@ static int stripe_end_io(struct dm_target *ti, struct bio *bio,
        if (!error)
                return 0; /* I/O complete */
 
-       if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio))
+       if ((error == -EWOULDBLOCK) && bio_rw_flagged(bio, BIO_RW_AHEAD))
                return error;
 
        if (error == -EOPNOTSUPP)
@@ -304,15 +313,43 @@ static int stripe_end_io(struct dm_target *ti, struct bio *bio,
        return error;
 }
 
+static int stripe_iterate_devices(struct dm_target *ti,
+                                 iterate_devices_callout_fn fn, void *data)
+{
+       struct stripe_c *sc = ti->private;
+       int ret = 0;
+       unsigned i = 0;
+
+       do {
+               ret = fn(ti, sc->stripe[i].dev,
+                        sc->stripe[i].physical_start,
+                        sc->stripe_width, data);
+       } while (!ret && ++i < sc->stripes);
+
+       return ret;
+}
+
+static void stripe_io_hints(struct dm_target *ti,
+                           struct queue_limits *limits)
+{
+       struct stripe_c *sc = ti->private;
+       unsigned chunk_size = (sc->chunk_mask + 1) << 9;
+
+       blk_limits_io_min(limits, chunk_size);
+       blk_limits_io_opt(limits, chunk_size * sc->stripes);
+}
+
 static struct target_type stripe_target = {
        .name   = "striped",
-       .version = {1, 1, 0},
+       .version = {1, 3, 0},
        .module = THIS_MODULE,
        .ctr    = stripe_ctr,
        .dtr    = stripe_dtr,
        .map    = stripe_map,
        .end_io = stripe_end_io,
        .status = stripe_status,
+       .iterate_devices = stripe_iterate_devices,
+       .io_hints = stripe_io_hints,
 };
 
 int __init dm_stripe_init(void)
@@ -320,8 +357,10 @@ int __init dm_stripe_init(void)
        int r;
 
        r = dm_register_target(&stripe_target);
-       if (r < 0)
+       if (r < 0) {
                DMWARN("target registration failed");
+               return r;
+       }
 
        kstriped = create_singlethread_workqueue("kstriped");
        if (!kstriped) {
@@ -335,9 +374,7 @@ int __init dm_stripe_init(void)
 
 void dm_stripe_exit(void)
 {
-       if (dm_unregister_target(&stripe_target))
-               DMWARN("target unregistration failed");
-
+       dm_unregister_target(&stripe_target);
        destroy_workqueue(kstriped);
 
        return;