Further to this thread started by Bryan Holty:
http://marc.theaimsgroup.com/?l=linux-scsi&m=114306885116728&w=2
Here is the reworked patch again. This time it has been
tested with a program provided by Bryan. The patch is
against lk 2.6.16 .
Changelog:
- when the sg driver is unable to setup direct IO,
free that scatter gather list prior to falling
back to indirect IO
Signed-off-by: Douglas Gilbert <dougg@xxxxxxxxxx>
Doug Gilbert
--- linux/drivers/scsi/sg.c 2006-03-20 10:08:49.000000000 -0500
+++ linux/drivers/scsi/sg.c2616dio_lk 2006-03-22 18:26:23.000000000 -0500
@@ -1834,8 +1834,10 @@
res = st_map_user_pages(schp->buffer, mx_sc_elems,
(unsigned long)hp->dxferp, dxfer_len,
(SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
- if (res <= 0)
+ if (res <= 0) {
+ sg_remove_scat(schp);
return 1;
+ }
schp->k_use_sg = res;
schp->dio_in_use = 1;
hp->info |= SG_INFO_DIRECT_IO;
