[SCSI] bug fix for free list handling
commit:
commit 542bd1377a963070bc4a03ff7d2690ddf3920596
Author: James Bottomley <James.Bottomley@HansenPartnership.com>
Date: Mon Apr 21 10:57:20 2008 -0500
[SCSI] fix SLUB WARN_ON
Fixed another problem in free list handling by moving list allocation
from scsi_host_alloc() to scsi_add_host(). Unfortunately it
introduced a new failure mode in that hosts can pass straight from
alloc to put without going through add, leaving the free list
uninitialised.
Fix by checking shost->cmd_pool on the release path to see if it got
initialised.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 12d69d7..749c9c7 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -469,6 +469,7 @@
cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);
if (!cmd) {
scsi_put_host_cmd_pool(gfp_mask);
+ shost->cmd_pool = NULL;
return -ENOMEM;
}
list_add(&cmd->list, &shost->free_list);
@@ -481,6 +482,13 @@
*/
void scsi_destroy_command_freelist(struct Scsi_Host *shost)
{
+ /*
+ * If cmd_pool is NULL the free list was not initialized, so
+ * do not attempt to release resources.
+ */
+ if (!shost->cmd_pool)
+ return;
+
while (!list_empty(&shost->free_list)) {
struct scsi_cmnd *cmd;