[PATCH] s390: lcs multicast deadlock.
From: Thomas Spatzier <[email protected]>
lcs network driver changes:
- Fix deadlock on card->ipm_lock.
Signed-off-by: Martin Schwidefsky <[email protected]>
diffstat:
drivers/s390/net/lcs.c | 56 +++++++++++++++++++++++++++++++++++--------------
1 files changed, 41 insertions(+), 15 deletions(-)
diff -urN linux-2.6/drivers/s390/net/lcs.c linux-2.6-s390/drivers/s390/net/lcs.c
--- linux-2.6/drivers/s390/net/lcs.c Fri Sep 3 15:26:13 2004
+++ linux-2.6-s390/drivers/s390/net/lcs.c Fri Sep 3 15:26:31 2004
@@ -11,7 +11,7 @@
* Frank Pavlic ([email protected]) and
* Martin Schwidefsky <[email protected]>
*
- * $Revision: 1.89 $ $Date: 2004/08/24 10:49:27 $
+ * $Revision: 1.92 $ $Date: 2004/09/03 08:06:11 $
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -59,7 +59,7 @@
/**
* initialization string for output
*/
-#define VERSION_LCS_C "$Revision: 1.89 $"
+#define VERSION_LCS_C "$Revision: 1.92 $"
static char version[] __initdata = "LCS driver ("VERSION_LCS_C "/" VERSION_LCS_H ")";
static char debug_buffer[255];
@@ -454,17 +454,21 @@
lcs_clear_multicast_list(struct lcs_card *card)
{
#ifdef CONFIG_IP_MULTICAST
- struct list_head *l, *n;
struct lcs_ipm_list *ipm;
unsigned long flags;
+
/* Free multicast list. */
LCS_DBF_TEXT(3, setup, "clmclist");
spin_lock_irqsave(&card->ipm_lock, flags);
- list_for_each_safe(l, n, &card->ipm_list) {
- ipm = list_entry(l, struct lcs_ipm_list, list);
+ while (!list_empty(&card->ipm_list)){
+ ipm = list_entry(card->ipm_list.next,
+ struct lcs_ipm_list, list);
list_del(&ipm->list);
- if (ipm->ipm_state != LCS_IPM_STATE_SET_REQUIRED)
+ if (ipm->ipm_state != LCS_IPM_STATE_SET_REQUIRED){
+ spin_unlock_irqrestore(&card->ipm_lock, flags);
lcs_send_delipm(card, ipm);
+ spin_lock_irqsave(&card->ipm_lock, flags);
+ }
kfree(ipm);
}
spin_unlock_irqrestore(&card->ipm_lock, flags);
@@ -1111,31 +1115,53 @@
static void
lcs_fix_multicast_list(struct lcs_card *card)
{
- struct list_head *l, *n;
- struct lcs_ipm_list *ipm;
+ struct list_head failed_list;
+ struct lcs_ipm_list *ipm, *tmp;
unsigned long flags;
+ int rc;
LCS_DBF_TEXT(4,trace, "fixipm");
+ INIT_LIST_HEAD(&failed_list);
spin_lock_irqsave(&card->ipm_lock, flags);
- list_for_each_safe(l, n, &card->ipm_list) {
- ipm = list_entry(l, struct lcs_ipm_list, list);
+list_modified:
+ list_for_each_entry_safe(ipm, tmp, &card->ipm_list, list){
switch (ipm->ipm_state) {
case LCS_IPM_STATE_SET_REQUIRED:
- if (lcs_send_setipm(card, ipm))
+ /* del from ipm_list so noone else can tamper with
+ * this entry */
+ list_del_init(&ipm->list);
+ spin_unlock_irqrestore(&card->ipm_lock, flags);
+ rc = lcs_send_setipm(card, ipm);
+ spin_lock_irqsave(&card->ipm_lock, flags);
+ if (rc) {
PRINT_INFO("Adding multicast address failed."
"Table possibly full!\n");
- else
+ /* store ipm in failed list -> will be added
+ * to ipm_list again, so a retry will be done
+ * during the next call of this function */
+ list_add_tail(&ipm->list, &failed_list);
+ } else {
ipm->ipm_state = LCS_IPM_STATE_ON_CARD;
- break;
+ /* re-insert into ipm_list */
+ list_add_tail(&ipm->list, &card->ipm_list);
+ }
+ goto list_modified;
case LCS_IPM_STATE_DEL_REQUIRED:
- lcs_send_delipm(card, ipm);
list_del(&ipm->list);
+ spin_unlock_irqrestore(&card->ipm_lock, flags);
+ lcs_send_delipm(card, ipm);
+ spin_lock_irqsave(&card->ipm_lock, flags);
kfree(ipm);
- break;
+ goto list_modified;
case LCS_IPM_STATE_ON_CARD:
break;
}
}
+ /* re-insert all entries from the failed_list into ipm_list */
+ list_for_each_entry(ipm, &failed_list, list) {
+ list_del_init(&ipm->list);
+ list_add_tail(&ipm->list, &card->ipm_list);
+ }
spin_unlock_irqrestore(&card->ipm_lock, flags);
if (card->state == DEV_STATE_UP)
netif_wake_queue(card->dev);