linux-next: manual merge of the akpm tree with the vfs tree

[Stephen Rothwell]

Hi Andrew,

Today's linux-next merge of the akpm tree got a conflict in ipc/util.c
between commit 823a5ed16606 ("ipc_schedule_free() can do vfree() now")
from the vfs tree and commit "ipc: make refcounter atomic" from the akpm
tree.

I fixed it up (I hope - see below) and can carry the fix as necessary (no
action is required).

-- 
Cheers,
Stephen Rothwell                    sfr@xxxxxxxxxxxxxxxx

diff --cc ipc/util.c
index 6515f95,5e60ebd..0000000
--- a/ipc/util.c
+++ b/ipc/util.c
@@@ -477,7 -478,8 +477,7 @@@ void ipc_free(void* ptr, int size
   */
  struct ipc_rcu_hdr
  {
- 	int refcount;
+ 	atomic_t refcount;
 -	int is_vmalloc;
  	void *data[0];
  };
  
@@@ -497,30 -516,48 +497,28 @@@ struct ipc_rcu_grac
   *	@size: size desired
   *
   *	Allocate memory for the rcu header structure +  the object.
-  *	Returns the pointer to the object.
-  *	NULL is returned if the allocation fails. 
+  *	Returns the pointer to the object or NULL upon failure.
   */
-  
- void* ipc_rcu_alloc(int size)
+ void *ipc_rcu_alloc(int size)
  {
 -	void* out;
 -
 -	/*
 -	 * We prepend the allocation with the rcu struct, and
 -	 * workqueue if necessary (for vmalloc).
 +	size_t len = size + HDRLEN;
 +	void *out;
 +	/* 
 +	 * We prepend the allocation with the rcu struct
  	 */
 -	if (rcu_use_vmalloc(size)) {
 -		out = vmalloc(HDRLEN_VMALLOC + size);
 -		if (!out)
 -			goto done;
 -
 -		out += HDRLEN_VMALLOC;
 -		container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 1;
 -	} else {
 -		out = kmalloc(HDRLEN_KMALLOC + size, GFP_KERNEL);
 -		if (!out)
 -			goto done;
 -
 -		out += HDRLEN_KMALLOC;
 -		container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 0;
 +	out = (len > PAGE_SIZE) ? vmalloc(len) : kmalloc(len, GFP_KERNEL);
 +	if (out) {
 +		out += HDRLEN;
- 		container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
++		atomic_set(&container_of(out, struct ipc_rcu_hdr, data)->refcount, 1);
  	}
  	return out;
  }
  
- void ipc_rcu_getref(void *ptr)
+ int ipc_rcu_getref(void *ptr)
  {
- 	container_of(ptr, struct ipc_rcu_hdr, data)->refcount++;
+ 	return atomic_inc_not_zero(&container_of(ptr, struct ipc_rcu_hdr, data)->refcount);
  }
  
 -static void ipc_do_vfree(struct work_struct *work)
 -{
 -	vfree(container_of(work, struct ipc_rcu_sched, work));
 -}
 -
  /**
   * ipc_schedule_free - free ipc + rcu space
   * @head: RCU callback structure for queued work
@@@ -534,10 -580,10 +532,10 @@@ static void ipc_schedule_free(struct rc
  
  void ipc_rcu_putref(void *ptr)
  {
- 	if (--container_of(ptr, struct ipc_rcu_hdr, data)->refcount > 0)
+ 	if (!atomic_dec_and_test(&container_of(ptr, struct ipc_rcu_hdr, data)->refcount))
  		return;
  
 -	if (container_of(ptr, struct ipc_rcu_hdr, data)->is_vmalloc) {
 +	if (is_vmalloc_addr(ptr)) {
  		call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
  				ipc_schedule_free);
  	} else {

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