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 ea49834377c8e17b6e8b221e4bd58389a8d7c32e..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;
@@ -290,6 +291,12 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
        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
         * send a zero-sized flush.
@@ -386,6 +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);
@@ -394,7 +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;
@@ -402,15 +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;
@@ -433,7 +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;