From: David Howells <bartbanter@hotmail.com>
Date: Sun, 20 Jan 2002 08:41:28 +0000 (+0000)
Subject: STABLE12-linux-alloc-avoid-potential-recursion-freeing-memory-and-schedule-when-vmall... 
X-Git-Tag: openafs-stable-1_2_3~43
X-Git-Url: https://git.michaelhowe.org/gitweb/?a=commitdiff_plain;h=4cf825c98f163dd2577877cb44d65d6a4d44e53d;p=packages%2Fo%2Fopenafs.git

STABLE12-linux-alloc-avoid-potential-recursion-freeing-memory-and-schedule-when-vmalloc-fails-20020120


"The first is to change the gfp_mask passed to kmalloc(). Using GFP_KERNEL,
  it is possible that the VM will call back to the filesystem to free up
  memory to satisfy the kmalloc request. GFP_NOFS will prevent this possible
  recursion. I believe GFP_NOFS first appeared in the 2.4.6 kernel.

  The second change involves the call to schedule() when vmalloc() fails. This
  can also cause a hang. The schedule() call could be replaced with:

  set_current_state(TASK_INTERRUPTIBLE);
  schedule_timeout(HZ);"
---

diff --git a/src/afs/LINUX/osi_alloc.c b/src/afs/LINUX/osi_alloc.c
index 9169ed624..580e89961 100644
--- a/src/afs/LINUX/osi_alloc.c
+++ b/src/afs/LINUX/osi_alloc.c
@@ -87,7 +87,13 @@ static void *linux_alloc(unsigned int asize)
 
     /*  if we can use kmalloc use it to allocate the required memory. */
     if (asize <  MAX_KMALLOC_SIZE) {
-        new = (void *)(unsigned long)kmalloc(asize, GFP_KERNEL);
+        new = (void *)(unsigned long)kmalloc(asize, 
+#ifdef GFP_NOFS
+					     GFP_NOFS
+#else
+					     GFP_KERNEL
+#endif
+					     );
         if (new) /* piggy back alloc type */
             (unsigned long)new |= KM_TYPE;
     }
@@ -97,7 +103,8 @@ static void *linux_alloc(unsigned int asize)
             if (--max_wait <=0) {
 		break;
             }
-	    schedule();
+	    set_current_state(TASK_INTERRUPTIBLE);
+	    schedule_timeout(HZ);
         }
 	if (new) /* piggy back alloc type */
 	    (unsigned long)new |= VM_TYPE;