ANDROID: dm verity: add minimum prefetch size

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / drivers / md / dm-verity-target.c

diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index 9d3d4b2972011f090696e9e9b9105a80b967e272..c7e97cf6e7fb1ac118eebe3df4350b100985ce23 100644 (file)
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -501,6 +501,7 @@ static void verity_prefetch_io(struct work_struct *work)
                container_of(work, struct dm_verity_prefetch_work, work);
        struct dm_verity *v = pw->v;
        int i;
+       sector_t prefetch_size;
 
        for (i = v->levels - 2; i >= 0; i--) {
                sector_t hash_block_start;
@@ -523,8 +524,14 @@ static void verity_prefetch_io(struct work_struct *work)
                                hash_block_end = v->hash_blocks - 1;
                }
 no_prefetch_cluster:
+               // for emmc, it is more efficient to send bigger read
+               prefetch_size = max((sector_t)CONFIG_DM_VERITY_HASH_PREFETCH_MIN_SIZE,
+                       hash_block_end - hash_block_start + 1);
+               if ((hash_block_start + prefetch_size) >= (v->hash_start + v->hash_blocks)) {
+                       prefetch_size = hash_block_end - hash_block_start + 1;
+               }
                dm_bufio_prefetch(v->bufio, hash_block_start,
-                                 hash_block_end - hash_block_start + 1);
+                                 prefetch_size);
        }
 
        kfree(pw);