[PARISC] fix null ptr deref in unwind.c

[sfrench/cifs-2.6.git] / block / ll_rw_blk.c

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 3de06953ac33d24ce669c35f0e8ffdbb4bcb9661..6b5173ac81313d8adb5c1d7b521559f565bb209b 100644 (file)
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1704,7 +1704,7 @@ EXPORT_SYMBOL(blk_stop_queue);
  *     on a queue, such as calling the unplug function after a timeout.
  *     A block device may call blk_sync_queue to ensure that any
  *     such activity is cancelled, thus allowing it to release resources
- *     the the callbacks might use. The caller must already have made sure
+ *     that the callbacks might use. The caller must already have made sure
  *     that its ->make_request_fn will not re-add plugging prior to calling
  *     this function.
  *
@@ -1712,7 +1712,6 @@ EXPORT_SYMBOL(blk_stop_queue);
 void blk_sync_queue(struct request_queue *q)
 {
        del_timer_sync(&q->unplug_timer);
-       kblockd_flush();
 }
 EXPORT_SYMBOL(blk_sync_queue);
 
@@ -1925,6 +1924,8 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
        blk_queue_max_hw_segments(q, MAX_HW_SEGMENTS);
        blk_queue_max_phys_segments(q, MAX_PHYS_SEGMENTS);
 
+       q->sg_reserved_size = INT_MAX;
+
        /*
         * all done
         */
@@ -2556,6 +2557,7 @@ int blk_rq_map_kern(request_queue_t *q, struct request *rq, void *kbuf,
                bio->bi_rw |= (1 << BIO_RW);
 
        blk_rq_bio_prep(q, rq, bio);
+       blk_queue_bounce(q, &rq->bio);
        rq->buffer = rq->data = NULL;
        return 0;
 }
@@ -3114,7 +3116,7 @@ static inline int should_fail_request(struct bio *bio)
  * bi_sector for remaps as it sees fit.  So the values of these fields
  * should NOT be depended on after the call to generic_make_request.
  */
-void generic_make_request(struct bio *bio)
+static inline void __generic_make_request(struct bio *bio)
 {
        request_queue_t *q;
        sector_t maxsector;
@@ -3213,6 +3215,57 @@ end_io:
        } while (ret);
 }
 
+/*
+ * We only want one ->make_request_fn to be active at a time,
+ * else stack usage with stacked devices could be a problem.
+ * So use current->bio_{list,tail} to keep a list of requests
+ * submited by a make_request_fn function.
+ * current->bio_tail is also used as a flag to say if
+ * generic_make_request is currently active in this task or not.
+ * If it is NULL, then no make_request is active.  If it is non-NULL,
+ * then a make_request is active, and new requests should be added
+ * at the tail
+ */
+void generic_make_request(struct bio *bio)
+{
+       if (current->bio_tail) {
+               /* make_request is active */
+               *(current->bio_tail) = bio;
+               bio->bi_next = NULL;
+               current->bio_tail = &bio->bi_next;
+               return;
+       }
+       /* following loop may be a bit non-obvious, and so deserves some
+        * explanation.
+        * Before entering the loop, bio->bi_next is NULL (as all callers
+        * ensure that) so we have a list with a single bio.
+        * We pretend that we have just taken it off a longer list, so
+        * we assign bio_list to the next (which is NULL) and bio_tail
+        * to &bio_list, thus initialising the bio_list of new bios to be
+        * added.  __generic_make_request may indeed add some more bios
+        * through a recursive call to generic_make_request.  If it
+        * did, we find a non-NULL value in bio_list and re-enter the loop
+        * from the top.  In this case we really did just take the bio
+        * of the top of the list (no pretending) and so fixup bio_list and
+        * bio_tail or bi_next, and call into __generic_make_request again.
+        *
+        * The loop was structured like this to make only one call to
+        * __generic_make_request (which is important as it is large and
+        * inlined) and to keep the structure simple.
+        */
+       BUG_ON(bio->bi_next);
+       do {
+               current->bio_list = bio->bi_next;
+               if (bio->bi_next == NULL)
+                       current->bio_tail = &current->bio_list;
+               else
+                       bio->bi_next = NULL;
+               __generic_make_request(bio);
+               bio = current->bio_list;
+       } while (bio);
+       current->bio_tail = NULL; /* deactivate */
+}
+
 EXPORT_SYMBOL(generic_make_request);
 
 /**
@@ -3505,7 +3558,7 @@ static int blk_cpu_notify(struct notifier_block *self, unsigned long action,
         * If a CPU goes away, splice its entries to the current CPU
         * and trigger a run of the softirq
         */
-       if (action == CPU_DEAD) {
+       if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
                int cpu = (unsigned long) hcpu;
 
                local_irq_disable();
@@ -3629,11 +3682,11 @@ int kblockd_schedule_work(struct work_struct *work)
 
 EXPORT_SYMBOL(kblockd_schedule_work);
 
-void kblockd_flush(void)
+void kblockd_flush_work(struct work_struct *work)
 {
-       flush_workqueue(kblockd_workqueue);
+       cancel_work_sync(work);
 }
-EXPORT_SYMBOL(kblockd_flush);
+EXPORT_SYMBOL(kblockd_flush_work);
 
 int __init blk_dev_init(void)
 {
@@ -3741,6 +3794,7 @@ static struct io_context *current_io_context(gfp_t gfp_flags, int node)
                ret->nr_batch_requests = 0; /* because this is 0 */
                ret->aic = NULL;
                ret->cic_root.rb_node = NULL;
+               ret->ioc_data = NULL;
                /* make sure set_task_ioprio() sees the settings above */
                smp_wmb();
                tsk->io_context = ret;
@@ -3748,7 +3802,6 @@ static struct io_context *current_io_context(gfp_t gfp_flags, int node)
 
        return ret;
 }
-EXPORT_SYMBOL(current_io_context);
 
 /*
  * If the current task has no IO context then create one and initialise it.