[SCSI] fix SLUB WARN_ON
James Bottomley [Mon, 21 Apr 2008 15:57:20 +0000 (10:57 -0500)]
We're getting a WARN_ON from SLUB indicating that we're trying to free
caches with in-use objects.  The root cause is a new dependency in the
command/sense free on unchecked_isa_dma.  The WARN_ON is caused by
drivers which change this in their setup after the command/sense cache
is allocated.

The fix is to move the allocation of this cache into scsi_add_host()
so things like gdth have an opportunity to modify it between alloc and
add (but *not* after).

The true fix would be to move unchecked_isa_dma into the template and
out of the host, so it because a truly read only variable.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/hosts.c

index 4e811ca..3690360 100644 (file)
@@ -199,9 +199,13 @@ int scsi_add_host(struct Scsi_Host *shost, struct device *dev)
        if (!shost->can_queue) {
                printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
                                sht->name);
-               goto out;
+               goto fail;
        }
 
+       error = scsi_setup_command_freelist(shost);
+       if (error)
+               goto fail;
+
        if (!shost->shost_gendev.parent)
                shost->shost_gendev.parent = dev ? dev : &platform_bus;
 
@@ -255,6 +259,8 @@ int scsi_add_host(struct Scsi_Host *shost, struct device *dev)
  out_del_gendev:
        device_del(&shost->shost_gendev);
  out:
+       scsi_destroy_command_freelist(shost);
+ fail:
        return error;
 }
 EXPORT_SYMBOL(scsi_add_host);
@@ -381,10 +387,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
        else
                shost->dma_boundary = 0xffffffff;
 
-       rval = scsi_setup_command_freelist(shost);
-       if (rval)
-               goto fail_kfree;
-
        device_initialize(&shost->shost_gendev);
        snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d",
                shost->host_no);
@@ -404,14 +406,12 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
                        "scsi_eh_%d", shost->host_no);
        if (IS_ERR(shost->ehandler)) {
                rval = PTR_ERR(shost->ehandler);
-               goto fail_destroy_freelist;
+               goto fail_kfree;
        }
 
        scsi_proc_hostdir_add(shost->hostt);
        return shost;
 
- fail_destroy_freelist:
-       scsi_destroy_command_freelist(shost);
  fail_kfree:
        kfree(shost);
        return NULL;