uml: dump core on panic

[firefly-linux-kernel-4.4.55.git] / block / ll_rw_blk.c

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 5d472e47c125e5d1786ebdc2b107e1abc7928cc9..5873861e1dbbfa6eb5b808a77f0d4c2771ed0c33 100644 (file)
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1221,7 +1221,7 @@ void blk_recount_segments(request_queue_t *q, struct bio *bio)
                 * considered part of another segment, since that might
                 * change with the bounce page.
                 */
-               high = page_to_pfn(bv->bv_page) >= q->bounce_pfn;
+               high = page_to_pfn(bv->bv_page) > q->bounce_pfn;
                if (high || highprv)
                        goto new_hw_segment;
                if (cluster) {
@@ -1264,7 +1264,7 @@ new_hw_segment:
        bio->bi_hw_segments = nr_hw_segs;
        bio->bi_flags |= (1 << BIO_SEG_VALID);
 }
-
+EXPORT_SYMBOL(blk_recount_segments);
 
 static int blk_phys_contig_segment(request_queue_t *q, struct bio *bio,
                                   struct bio *nxt)
@@ -1925,6 +1925,8 @@ 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
         */
@@ -2405,6 +2407,7 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
                    unsigned long len)
 {
        unsigned long bytes_read = 0;
+       struct bio *bio = NULL;
        int ret;
 
        if (len > (q->max_hw_sectors << 9))
@@ -2431,6 +2434,8 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
                ret = __blk_rq_map_user(q, rq, ubuf, map_len);
                if (ret < 0)
                        goto unmap_rq;
+               if (!bio)
+                       bio = rq->bio;
                bytes_read += ret;
                ubuf += ret;
        }
@@ -2438,7 +2443,7 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
        rq->buffer = rq->data = NULL;
        return 0;
 unmap_rq:
-       blk_rq_unmap_user(rq);
+       blk_rq_unmap_user(bio);
        return ret;
 }
 
@@ -2450,6 +2455,7 @@ EXPORT_SYMBOL(blk_rq_map_user);
  * @rq:                request to map data to
  * @iov:       pointer to the iovec
  * @iov_count: number of elements in the iovec
+ * @len:       I/O byte count
  *
  * Description:
  *    Data will be mapped directly for zero copy io, if possible. Otherwise
@@ -2495,27 +2501,33 @@ EXPORT_SYMBOL(blk_rq_map_user_iov);
 
 /**
  * blk_rq_unmap_user - unmap a request with user data
- * @rq:                rq to be unmapped
+ * @bio:              start of bio list
  *
  * Description:
- *    Unmap a rq previously mapped by blk_rq_map_user().
- *    rq->bio must be set to the original head of the request.
+ *    Unmap a rq previously mapped by blk_rq_map_user(). The caller must
+ *    supply the original rq->bio from the blk_rq_map_user() return, since
+ *    the io completion may have changed rq->bio.
  */
-int blk_rq_unmap_user(struct request *rq)
+int blk_rq_unmap_user(struct bio *bio)
 {
-       struct bio *bio, *mapped_bio;
+       struct bio *mapped_bio;
+       int ret = 0, ret2;
 
-       while ((bio = rq->bio)) {
-               if (bio_flagged(bio, BIO_BOUNCED))
+       while (bio) {
+               mapped_bio = bio;
+               if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
                        mapped_bio = bio->bi_private;
-               else
-                       mapped_bio = bio;
 
-               __blk_rq_unmap_user(mapped_bio);
-               rq->bio = bio->bi_next;
-               bio_put(bio);
+               ret2 = __blk_rq_unmap_user(mapped_bio);
+               if (ret2 && !ret)
+                       ret = ret2;
+
+               mapped_bio = bio;
+               bio = bio->bi_next;
+               bio_put(mapped_bio);
        }
-       return 0;
+
+       return ret;
 }
 
 EXPORT_SYMBOL(blk_rq_unmap_user);
@@ -3648,8 +3660,8 @@ int __init blk_dev_init(void)
        open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL);
        register_hotcpu_notifier(&blk_cpu_notifier);
 
-       blk_max_low_pfn = max_low_pfn;
-       blk_max_pfn = max_pfn;
+       blk_max_low_pfn = max_low_pfn - 1;
+       blk_max_pfn = max_pfn - 1;
 
        return 0;
 }
@@ -3731,6 +3743,7 @@ 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;