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

From: Stephen Rothwell
Date: Tue Apr 30 2013 - 01:55:16 EST


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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