Patch from Jens Axboe to synchronously flush block requests from our

ChangeSet 1.1405, 2005/03/31 09:09:50+01:00, kaf24@xxxxxxxxxxxxxxxxxxxx

        Patch from Jens Axboe to synchronously flush block requests from our
        backend driver down to the disk(s). Big improvement in blkdev
        performance.



 blkback.c |   16 ++++++----------
 1 files changed, 6 insertions(+), 10 deletions(-)


diff -Nru a/linux-2.6.11-xen-sparse/drivers/xen/blkback/blkback.c 
b/linux-2.6.11-xen-sparse/drivers/xen/blkback/blkback.c
--- a/linux-2.6.11-xen-sparse/drivers/xen/blkback/blkback.c     2005-03-31 
04:05:37 -05:00
+++ b/linux-2.6.11-xen-sparse/drivers/xen/blkback/blkback.c     2005-03-31 
04:05:37 -05:00
@@ -512,7 +512,6 @@
     for ( i = 0; i < nr_psegs; i++ )
     {
         struct bio *bio;
-        struct bio_vec *bv;
 
         bio = bio_alloc(GFP_ATOMIC, 1);
         if ( unlikely(bio == NULL) )
@@ -525,17 +524,14 @@
         bio->bi_private = pending_req;
         bio->bi_end_io  = end_block_io_op;
         bio->bi_sector  = phys_seg[i].sector_number;
-        bio->bi_rw      = operation;
 
-        bv = bio_iovec_idx(bio, 0);
-        bv->bv_page   = virt_to_page(MMAP_VADDR(pending_idx, i));
-        bv->bv_len    = phys_seg[i].nr_sects << 9;
-        bv->bv_offset = phys_seg[i].buffer & ~PAGE_MASK;
+        bio_add_page(
+            bio,
+            virt_to_page(MMAP_VADDR(pending_idx, i)),
+            phys_seg[i].nr_sects << 9,
+            phys_seg[i].buffer & ~PAGE_MASK);
 
-        bio->bi_size    = bv->bv_len;
-        bio->bi_vcnt++;
-
-        submit_bio(operation, bio);
+        submit_bio(operation | (1 << BIO_RW_SYNC), bio);
     }
 #endif