Review fixes:
- Addressed Joe's comment on function header
Bug: libfc/fnic connected to JBODs. Rapidly pull/push in the JBODs to
generate multiple RSCNs rapidly. There is a race in the remote port/disc
state machine that causes multiple entries for the same remote port
in /sys/class/fc_remote_ports.
Rogue ports are now tracked in a separate rogue list until they go to
READY state and get moved to the real rports list. An incoming RSCN
that causes rediscovery or causes a re-plogi to a remote port does not
search the rogues list, and thus fails to log it off before starting a
new plogi. This causes a race condition where 2 rogue ports are created
to the same remote port. (The same problem existed when rogues were not
tracked in any list)
This patch adds a fix by searching the rogue list in addition to the
regular rport list on incoming RSCNs.
fc_disc_lookup_rport() is also called for incoming rport requests. I
wanted to avoid modifying that function to also search in the rogue list,
since that would result into a case where an incoming Plogi would find the
rogue session, and significant change is required to support that.
So, instead, I added a new function fc_disc_lookup_all_ports() which
searches in both lists. It is called on incoming RSCNs. On incoming rport
requests, like Plogi etc, existing fc_disc_lookup_rport() function is used,
thus avoiding changes to that code path.
Also, before re-discovery is initiated, the rogue list is searched and
all rogue ports are first logged off.
Test: Tested the fix by running the same test case as above. This time,
remote ports were logged off and re-logged on correctly, and resulted
in single entry per remote port.
Please verify bug and fix for libfc/fcoe driver.
Signed-off-by: Abhijeet Joglekar <[email protected]>
---
drivers/scsi/libfc/fc_disc.c | 43 ++++++++++++++++++++++++++++++++++++++++--
1 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/libfc/fc_disc.c b/drivers/scsi/libfc/fc_disc.c
index 6fabf66..6e2f6f5 100644
--- a/drivers/scsi/libfc/fc_disc.c
+++ b/drivers/scsi/libfc/fc_disc.c
@@ -56,6 +56,38 @@ static void fc_disc_single(struct fc_disc *, struct
fc_disc_port *);
static void fc_disc_restart(struct fc_disc *);
/**
+ * fc_disc_lookup_all_rports() - lookup both real and rogue ports by id
+ * @lport: Fibre Channel host port instance
+ * @port_id: remote port port_id to match
+ */
+struct fc_rport *fc_disc_lookup_all_rports(const struct fc_lport *lport,
+ u32 port_id)
+{
+ const struct fc_disc *disc = &lport->disc;
+ struct fc_rport *rport, *found = NULL;
+ struct fc_rport_libfc_priv *rdata;
+
+ list_for_each_entry(rdata, &disc->rports, peers) {
+ rport = PRIV_TO_RPORT(rdata);
+ if (rport->port_id == port_id) {
+ found = rport;
+ goto out;
+ }
+ }
+
+ list_for_each_entry(rdata, &disc->rogue_rports, peers) {
+ rport = PRIV_TO_RPORT(rdata);
+ if (rport->port_id == port_id) {
+ found = rport;
+ goto out;
+ }
+ }
+
+out:
+ return found;
+}
+
+/**
* fc_disc_lookup_rport() - lookup a remote port by port_id
* @lport: Fibre Channel host port instance
* @port_id: remote port port_id to match
@@ -249,10 +281,12 @@ static void fc_disc_recv_rscn_req(struct fc_seq *sp,
struct fc_frame *fp,
redisc, lport->state, disc->pending);
list_for_each_entry_safe(dp, next, &disc_ports, peers) {
list_del(&dp->peers);
- rport = lport->tt.rport_lookup(lport, dp->ids.port_id);
+ rport = fc_disc_lookup_all_rports(lport,
+ dp->ids.port_id);
if (rport) {
rdata = rport->dd_data;
- list_del(&rdata->peers);
+ if (rdata->trans_state != FC_PORTSTATE_ROGUE)
+ list_del(&rdata->peers);
lport->tt.rport_logoff(rport);
}
fc_disc_single(disc, dp);
@@ -320,6 +354,11 @@ static void fc_disc_restart(struct fc_disc *disc)
lport->tt.rport_logoff(rport);
}
+ list_for_each_entry_safe(rdata, next, &disc->rogue_rports, peers) {
+ rport = PRIV_TO_RPORT(rdata);
+ lport->tt.rport_logoff(rport);
+ }
+
disc->requested = 1;
if (!disc->pending)
fc_disc_gpn_ft_req(disc);
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