On Thu, Apr 05 2001, Jens Axboe wrote:
> To the LVM folks: you can't use b_dev or b_blocknr inside your
> make_request_fn, it destroys stacking drivers such as loop. And
> is just plain wrong in the general case too.
Irks, another one. lvm_make_request_fn also needs to call b_end_io
if a map fails. Updated patch attached, I'll collate further
patches if I find more :-)
--
Jens Axboe
--- /opt/kernel/linux-2.4.3/drivers/md/lvm.c Mon Jan 29 01:11:20 2001
+++ drivers/md/lvm.c Thu Apr 5 16:48:52 2001
@@ -148,6 +148,9 @@
* procfs is always supported now. (JT)
* 12/01/2001 - avoided flushing logical volume in case of shrinking
* because of unecessary overhead in case of heavy updates
+ * 05/04/2001 - lvm_map bugs: don't use b_blocknr/b_dev in lvm_map, it
+ * destroys stacking devices. call b_end_io on failed maps.
+ * (Jens Axboe)
*
*/
@@ -1480,14 +1483,14 @@
*/
static int lvm_map(struct buffer_head *bh, int rw)
{
- int minor = MINOR(bh->b_dev);
+ int minor = MINOR(bh->b_rdev);
int ret = 0;
ulong index;
ulong pe_start;
ulong size = bh->b_size >> 9;
- ulong rsector_tmp = bh->b_blocknr * size;
+ ulong rsector_tmp = bh->b_rsector;
ulong rsector_sav;
- kdev_t rdev_tmp = bh->b_dev;
+ kdev_t rdev_tmp = bh->b_rdev;
kdev_t rdev_sav;
vg_t *vg_this = vg[VG_BLK(minor)];
lv_t *lv = vg_this->lv[LV_BLK(minor)];
@@ -1676,8 +1679,12 @@
*/
static int lvm_make_request_fn(request_queue_t *q,
int rw,
- struct buffer_head *bh) {
- return (lvm_map(bh, rw) < 0) ? 0 : 1;
+ struct buffer_head *bh)
+{
+ int ret = lvm_map(bh, rw);
+ if (ret)
+ bh->b_end_io(bh, test_bit(BH_Uptodate, &bh->b_state));
+ return ret;
}
