block: allow large discard requests

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

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index 21f5025..8873b9b 100644 (file)
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -385,6 +385,8 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 
        while (nr_sects && !ret) {
                unsigned int sector_size = q->limits.logical_block_size;
+               unsigned int max_discard_sectors =
+                       min(q->limits.max_discard_sectors, UINT_MAX >> 9);
 
                bio = bio_alloc(gfp_mask, 1);
                if (!bio)
@@ -411,10 +413,10 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                 * touch many more blocks on disk than the actual payload
                 * length.
                 */
-               if (nr_sects > queue_max_hw_sectors(q)) {
-                       bio->bi_size = queue_max_hw_sectors(q) << 9;
-                       nr_sects -= queue_max_hw_sectors(q);
-                       sector += queue_max_hw_sectors(q);
+               if (nr_sects > max_discard_sectors) {
+                       bio->bi_size = max_discard_sectors << 9;
+                       nr_sects -= max_discard_sectors;
+                       sector += max_discard_sectors;
                } else {
                        bio->bi_size = nr_sects << 9;
                        nr_sects = 0;