Merge remote-tracking branch 'kwolf/for-anthony' into staging

* kwolf/for-anthony:
  ahci: SATA FIS is 20 bytes, not 0x20
  virtio-blk: Fix geometry sector calculation
  block: prevent snapshot mode $TMPDIR symlink attack
  sheepdog: fix return value of do_load_save_vm_state
  virtio: Fix compiler warning for non Linux hosts

1 files changed, 19 insertions, 2 deletions

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index f9e1896ea9..fe0774617b 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -147,9 +147,11 @@ static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s)
 
 static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
 {
+#ifdef __linux__
     int ret;
-    int status = VIRTIO_BLK_S_OK;
     int i;
+#endif
+    int status = VIRTIO_BLK_S_OK;
 
     /*
      * We require at least one output segment each for the virtio_blk_outhdr
@@ -489,7 +491,22 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
     stw_raw(&blkcfg.min_io_size, s->conf->min_io_size / blk_size);
     stw_raw(&blkcfg.opt_io_size, s->conf->opt_io_size / blk_size);
     blkcfg.heads = heads;
-    blkcfg.sectors = secs & ~s->sector_mask;
+    /*
+     * We must ensure that the block device capacity is a multiple of
+     * the logical block size. If that is not the case, lets use
+     * sector_mask to adopt the geometry to have a correct picture.
+     * For those devices where the capacity is ok for the given geometry
+     * we dont touch the sector value of the geometry, since some devices
+     * (like s390 dasd) need a specific value. Here the capacity is already
+     * cyls*heads*secs*blk_size and the sector value is not block size
+     * divided by 512 - instead it is the amount of blk_size blocks
+     * per track (cylinder).
+     */
+    if (bdrv_getlength(s->bs) /  heads / secs % blk_size) {
+        blkcfg.sectors = secs & ~s->sector_mask;
+    } else {
+        blkcfg.sectors = secs;
+    }
     blkcfg.size_max = 0;
     blkcfg.physical_block_exp = get_physical_block_exp(s->conf);
     blkcfg.alignment_offset = 0;