Merge tag 'iwlwifi-next-for-kalle-2014-12-30' of https://git.kernel.org/pub/scm/linux...

[cascardo/linux.git] / block / bio.c

diff --git a/block/bio.c b/block/bio.c
index 3e6e198..471d738 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -748,6 +748,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
                                }
                        }
 
+                       bio->bi_iter.bi_size += len;
                        goto done;
                }
 
@@ -764,28 +765,31 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
                return 0;
 
        /*
-        * we might lose a segment or two here, but rather that than
-        * make this too complex.
+        * setup the new entry, we might clear it again later if we
+        * cannot add the page
+        */
+       bvec = &bio->bi_io_vec[bio->bi_vcnt];
+       bvec->bv_page = page;
+       bvec->bv_len = len;
+       bvec->bv_offset = offset;
+       bio->bi_vcnt++;
+       bio->bi_phys_segments++;
+       bio->bi_iter.bi_size += len;
+
+       /*
+        * Perform a recount if the number of segments is greater
+        * than queue_max_segments(q).
         */
 
-       while (bio->bi_phys_segments >= queue_max_segments(q)) {
+       while (bio->bi_phys_segments > queue_max_segments(q)) {
 
                if (retried_segments)
-                       return 0;
+                       goto failed;
 
                retried_segments = 1;
                blk_recount_segments(q, bio);
        }
 
-       /*
-        * setup the new entry, we might clear it again later if we
-        * cannot add the page
-        */
-       bvec = &bio->bi_io_vec[bio->bi_vcnt];
-       bvec->bv_page = page;
-       bvec->bv_len = len;
-       bvec->bv_offset = offset;
-
        /*
         * if queue has other restrictions (eg varying max sector size
         * depending on offset), it can specify a merge_bvec_fn in the
@@ -795,7 +799,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
                struct bvec_merge_data bvm = {
                        .bi_bdev = bio->bi_bdev,
                        .bi_sector = bio->bi_iter.bi_sector,
-                       .bi_size = bio->bi_iter.bi_size,
+                       .bi_size = bio->bi_iter.bi_size - len,
                        .bi_rw = bio->bi_rw,
                };
 
@@ -803,23 +807,25 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
                 * merge_bvec_fn() returns number of bytes it can accept
                 * at this offset
                 */
-               if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) {
-                       bvec->bv_page = NULL;
-                       bvec->bv_len = 0;
-                       bvec->bv_offset = 0;
-                       return 0;
-               }
+               if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len)
+                       goto failed;
        }
 
        /* If we may be able to merge these biovecs, force a recount */
-       if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
+       if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
                bio->bi_flags &= ~(1 << BIO_SEG_VALID);
 
-       bio->bi_vcnt++;
-       bio->bi_phys_segments++;
  done:
-       bio->bi_iter.bi_size += len;
        return len;
+
+ failed:
+       bvec->bv_page = NULL;
+       bvec->bv_len = 0;
+       bvec->bv_offset = 0;
+       bio->bi_vcnt--;
+       bio->bi_iter.bi_size -= len;
+       blk_recount_segments(q, bio);
+       return 0;
 }
 
 /**
@@ -1739,6 +1745,34 @@ void bio_check_pages_dirty(struct bio *bio)
        }
 }
 
+void generic_start_io_acct(int rw, unsigned long sectors,
+                          struct hd_struct *part)
+{
+       int cpu = part_stat_lock();
+
+       part_round_stats(cpu, part);
+       part_stat_inc(cpu, part, ios[rw]);
+       part_stat_add(cpu, part, sectors[rw], sectors);
+       part_inc_in_flight(part, rw);
+
+       part_stat_unlock();
+}
+EXPORT_SYMBOL(generic_start_io_acct);
+
+void generic_end_io_acct(int rw, struct hd_struct *part,
+                        unsigned long start_time)
+{
+       unsigned long duration = jiffies - start_time;
+       int cpu = part_stat_lock();
+
+       part_stat_add(cpu, part, ticks[rw], duration);
+       part_round_stats(cpu, part);
+       part_dec_in_flight(part, rw);
+
+       part_stat_unlock();
+}
+EXPORT_SYMBOL(generic_end_io_acct);
+
 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 void bio_flush_dcache_pages(struct bio *bi)
 {