Merge branch 'akpm' (patches from Andrew Morton)

Merge first patch-bomb from Andrew Morton:
 - Some pidns/fork/exec tweaks
 - OCFS2 updates
 - Most of MM - there remain quite a few memcg parts which depend on
   pending core cgroups changes.  Which might have been already merged -
   I'll check tomorrow...
 - Various misc stuff all over the place
 - A few block bits which I never got around to sending to Jens -
   relatively minor things.
 - MAINTAINERS maintenance
 - A small number of lib/ updates
 - checkpatch updates
 - epoll
 - firmware/dmi-scan
 - Some kprobes work for S390
 - drivers/rtc updates
 - hfsplus feature work
 - vmcore feature work
 - rbtree upgrades
 - AOE updates
 - pktcdvd cleanups
 - PPS
 - memstick
 - w1
 - New "inittmpfs" feature, which does the obvious
 - More IPC work from Davidlohr.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (303 commits)
  lz4: fix compression/decompression signedness mismatch
  ipc: drop ipc_lock_check
  ipc, shm: drop shm_lock_check
  ipc: drop ipc_lock_by_ptr
  ipc, shm: guard against non-existant vma in shmdt(2)
  ipc: document general ipc locking scheme
  ipc,msg: drop msg_unlock
  ipc: rename ids->rw_mutex
  ipc,shm: shorten critical region for shmat
  ipc,shm: cleanup do_shmat pasta
  ipc,shm: shorten critical region for shmctl
  ipc,shm: make shmctl_nolock lockless
  ipc,shm: introduce shmctl_nolock
  ipc: drop ipcctl_pre_down
  ipc,shm: shorten critical region in shmctl_down
  ipc,shm: introduce lockless functions to obtain the ipc object
  initmpfs: use initramfs if rootfstype= or root= specified
  initmpfs: make rootfs use tmpfs when CONFIG_TMPFS enabled
  initmpfs: move rootfs code from fs/ramfs/ to init/
  initmpfs: move bdi setup from init_rootfs to init_ramfs
  ...

1 files changed, 39 insertions, 2 deletions

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index e7964296fd5..7811ed3b4e7 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -32,6 +32,7 @@
 #include <linux/string.h>
 #include <linux/bitops.h>
 #include <linux/rcupdate.h>
+#include <linux/hardirq.h>		/* in_interrupt() */
 
 
 #ifdef __KERNEL__
@@ -207,7 +208,12 @@ radix_tree_node_alloc(struct radix_tree_root *root)
 	struct radix_tree_node *ret = NULL;
 	gfp_t gfp_mask = root_gfp_mask(root);
 
-	if (!(gfp_mask & __GFP_WAIT)) {
+	/*
+	 * Preload code isn't irq safe and it doesn't make sence to use
+	 * preloading in the interrupt anyway as all the allocations have to
+	 * be atomic. So just do normal allocation when in interrupt.
+	 */
+	if (!(gfp_mask & __GFP_WAIT) && !in_interrupt()) {
 		struct radix_tree_preload *rtp;
 
 		/*
@@ -264,7 +270,7 @@ radix_tree_node_free(struct radix_tree_node *node)
  * To make use of this facility, the radix tree must be initialised without
  * __GFP_WAIT being passed to INIT_RADIX_TREE().
  */
-int radix_tree_preload(gfp_t gfp_mask)
+static int __radix_tree_preload(gfp_t gfp_mask)
 {
 	struct radix_tree_preload *rtp;
 	struct radix_tree_node *node;
@@ -288,9 +294,40 @@ int radix_tree_preload(gfp_t gfp_mask)
 out:
 	return ret;
 }
+
+/*
+ * Load up this CPU's radix_tree_node buffer with sufficient objects to
+ * ensure that the addition of a single element in the tree cannot fail.  On
+ * success, return zero, with preemption disabled.  On error, return -ENOMEM
+ * with preemption not disabled.
+ *
+ * To make use of this facility, the radix tree must be initialised without
+ * __GFP_WAIT being passed to INIT_RADIX_TREE().
+ */
+int radix_tree_preload(gfp_t gfp_mask)
+{
+	/* Warn on non-sensical use... */
+	WARN_ON_ONCE(!(gfp_mask & __GFP_WAIT));
+	return __radix_tree_preload(gfp_mask);
+}
 EXPORT_SYMBOL(radix_tree_preload);
 
 /*
+ * The same as above function, except we don't guarantee preloading happens.
+ * We do it, if we decide it helps. On success, return zero with preemption
+ * disabled. On error, return -ENOMEM with preemption not disabled.
+ */
+int radix_tree_maybe_preload(gfp_t gfp_mask)
+{
+	if (gfp_mask & __GFP_WAIT)
+		return __radix_tree_preload(gfp_mask);
+	/* Preloading doesn't help anything with this gfp mask, skip it */
+	preempt_disable();
+	return 0;
+}
+EXPORT_SYMBOL(radix_tree_maybe_preload);
+
+/*
  *	Return the maximum key which can be store into a
  *	radix tree with height HEIGHT.
  */