Merge tag 'v3.10.84' into update

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / md / dm-io.c

diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 1c46f97d6664a850ea286f90b6a36e82d6b73074..17cb2170e9d8628a0ba6686ea839de865a90543c 100644 (file)
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -10,6 +10,7 @@
 #include <linux/device-mapper.h>
 
 #include <linux/bio.h>
+#include <linux/completion.h>
 #include <linux/mempool.h>
 #include <linux/module.h>
 #include <linux/sched.h>
@@ -34,7 +35,7 @@ struct dm_io_client {
 struct io {
        unsigned long error_bits;
        atomic_t count;
-       struct task_struct *sleeper;
+       struct completion *wait;
        struct dm_io_client *client;
        io_notify_fn callback;
        void *context;
@@ -122,8 +123,8 @@ static void dec_count(struct io *io, unsigned int region, int error)
                        invalidate_kernel_vmap_range(io->vma_invalidate_address,
                                                     io->vma_invalidate_size);
 
-               if (io->sleeper)
-                       wake_up_process(io->sleeper);
+               if (io->wait)
+                       complete(io->wait);
 
                else {
                        unsigned long r = io->error_bits;
@@ -287,7 +288,14 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
        unsigned num_bvecs;
        sector_t remaining = where->count;
        struct request_queue *q = bdev_get_queue(where->bdev);
-       sector_t discard_sectors;
+       unsigned short logical_block_size = queue_logical_block_size(q);
+       sector_t num_sectors;
+
+       /* Reject unsupported discard requests */
+       if ((rw & REQ_DISCARD) && !blk_queue_discard(q)) {
+               dec_count(io, region, -EOPNOTSUPP);
+               return;
+       }
 
        /*
         * where->count may be zero if rw holds a flush and we need to
@@ -297,7 +305,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
                /*
                 * Allocate a suitably sized-bio.
                 */
-               if (rw & REQ_DISCARD)
+               if ((rw & REQ_DISCARD) || (rw & REQ_WRITE_SAME))
                        num_bvecs = 1;
                else
                        num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev),
@@ -310,9 +318,21 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
                store_io_and_region_in_bio(bio, io, region);
 
                if (rw & REQ_DISCARD) {
-                       discard_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
-                       bio->bi_size = discard_sectors << SECTOR_SHIFT;
-                       remaining -= discard_sectors;
+                       num_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
+                       bio->bi_size = num_sectors << SECTOR_SHIFT;
+                       remaining -= num_sectors;
+               } else if (rw & REQ_WRITE_SAME) {
+                       /*
+                        * WRITE SAME only uses a single page.
+                        */
+                       dp->get_page(dp, &page, &len, &offset);
+                       bio_add_page(bio, page, logical_block_size, offset);
+                       num_sectors = min_t(sector_t, q->limits.max_write_same_sectors, remaining);
+                       bio->bi_size = num_sectors << SECTOR_SHIFT;
+
+                       offset = 0;
+                       remaining -= num_sectors;
+                       dp->next_page(dp);
                } else while (remaining) {
                        /*
                         * Try and add as many pages as possible.
@@ -373,6 +393,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
         */
        volatile char io_[sizeof(struct io) + __alignof__(struct io) - 1];
        struct io *io = (struct io *)PTR_ALIGN(&io_, __alignof__(struct io));
+       DECLARE_COMPLETION_ONSTACK(wait);
 
        if (num_regions > 1 && (rw & RW_MASK) != WRITE) {
                WARN_ON(1);
@@ -381,7 +402,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
 
        io->error_bits = 0;
        atomic_set(&io->count, 1); /* see dispatch_io() */
-       io->sleeper = current;
+       io->wait = &wait;
        io->client = client;
 
        io->vma_invalidate_address = dp->vma_invalidate_address;
@@ -389,15 +410,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
 
        dispatch_io(rw, num_regions, where, dp, io, 1);
 
-       while (1) {
-               set_current_state(TASK_UNINTERRUPTIBLE);
-
-               if (!atomic_read(&io->count))
-                       break;
-
-               io_schedule();
-       }
-       set_current_state(TASK_RUNNING);
+       wait_for_completion_io(&wait);
 
        if (error_bits)
                *error_bits = io->error_bits;
@@ -420,7 +433,7 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions,
        io = mempool_alloc(client->pool, GFP_NOIO);
        io->error_bits = 0;
        atomic_set(&io->count, 1); /* see dispatch_io() */
-       io->sleeper = NULL;
+       io->wait = NULL;
        io->client = client;
        io->callback = fn;
        io->context = context;