block: prevent possible io_context->refcount overflow

[safe/jmp/linux-2.6] / block / blk-ioc.c

diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 012f065..d4ed600 100644 (file)
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -35,9 +35,9 @@ int put_io_context(struct io_context *ioc)
        if (ioc == NULL)
                return 1;
 
-       BUG_ON(atomic_read(&ioc->refcount) == 0);
+       BUG_ON(atomic_long_read(&ioc->refcount) == 0);
 
-       if (atomic_dec_and_test(&ioc->refcount)) {
+       if (atomic_long_dec_and_test(&ioc->refcount)) {
                rcu_read_lock();
                if (ioc->aic && ioc->aic->dtor)
                        ioc->aic->dtor(ioc->aic);
@@ -90,7 +90,7 @@ struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
 
        ret = kmem_cache_alloc_node(iocontext_cachep, gfp_flags, node);
        if (ret) {
-               atomic_set(&ret->refcount, 1);
+               atomic_long_set(&ret->refcount, 1);
                atomic_set(&ret->nr_tasks, 1);
                spin_lock_init(&ret->lock);
                ret->ioprio_changed = 0;
@@ -151,7 +151,7 @@ struct io_context *get_io_context(gfp_t gfp_flags, int node)
                ret = current_io_context(gfp_flags, node);
                if (unlikely(!ret))
                        break;
-       } while (!atomic_inc_not_zero(&ret->refcount));
+       } while (!atomic_long_inc_not_zero(&ret->refcount));
 
        return ret;
 }
@@ -163,8 +163,8 @@ void copy_io_context(struct io_context **pdst, struct io_context **psrc)
        struct io_context *dst = *pdst;
 
        if (src) {
-               BUG_ON(atomic_read(&src->refcount) == 0);
-               atomic_inc(&src->refcount);
+               BUG_ON(atomic_long_read(&src->refcount) == 0);
+               atomic_long_inc(&src->refcount);
                put_io_context(dst);
                *pdst = src;
        }