Re: [PATCH V2 2/3] xen: scsiback: add LUN of restored domain

From: Boris Ostrovsky
Date: Wed Feb 18 2015 - 12:03:41 EST


On 02/17/2015 02:02 AM, Juergen Gross wrote:
When a xen domain is being restored the LUN state of a pvscsi device
is "Connected" and not "Initialising" as in case of attaching a new
pvscsi LUN.

This must be taken into account when adding a new pvscsi device for
a domain as otherwise the pvscsi LUN won't be connected to the
SCSI target associated with it.


scsiback_do_add_lun() is being called from scsiback_frontend_changed() which eventually sets the state to Connected. Is the added test of
'try' an optimization or is it needed for correctness?

-boris



Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
drivers/xen/xen-scsiback.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 9faca6a..9d60176 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -992,7 +992,7 @@ found:
}

static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
- char *phy, struct ids_tuple *vir)
+ char *phy, struct ids_tuple *vir, int try)
{
if (!scsiback_add_translation_entry(info, phy, vir)) {
if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
@@ -1000,7 +1000,7 @@ static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
scsiback_del_translation_entry(info, vir);
}
- } else {
+ } else if (!try) {
xenbus_printf(XBT_NIL, info->dev->nodename, state,
"%d", XenbusStateClosed);
}
@@ -1060,10 +1060,19 @@ static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,

switch (op) {
case VSCSIBACK_OP_ADD_OR_DEL_LUN:
- if (device_state == XenbusStateInitialising)
- scsiback_do_add_lun(info, state, phy, &vir);
- if (device_state == XenbusStateClosing)
+ switch (device_state) {
+ case XenbusStateInitialising:
+ scsiback_do_add_lun(info, state, phy, &vir, 0);
+ break;
+ case XenbusStateConnected:
+ scsiback_do_add_lun(info, state, phy, &vir, 1);
+ break;
+ case XenbusStateClosing:
scsiback_do_del_lun(info, state, &vir);
+ break;
+ default:
+ break;
+ }
break;

case VSCSIBACK_OP_UPDATEDEV_STATE:


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