Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - a few misc things

 - kexec updates

 - DMA-mapping updates to better support networking DMA operations

 - IPC updates

 - various MM changes to improve DAX fault handling

 - lots of radix-tree changes, mainly to the test suite. All leading up
   to reimplementing the IDA/IDR code to be a wrapper layer over the
   radix-tree. However the final trigger-pulling patch is held off for
   4.11.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
  radix tree test suite: delete unused rcupdate.c
  radix tree test suite: add new tag check
  radix-tree: ensure counts are initialised
  radix tree test suite: cache recently freed objects
  radix tree test suite: add some more functionality
  idr: reduce the number of bits per level from 8 to 6
  rxrpc: abstract away knowledge of IDR internals
  tpm: use idr_find(), not idr_find_slowpath()
  idr: add ida_is_empty
  radix tree test suite: check multiorder iteration
  radix-tree: fix replacement for multiorder entries
  radix-tree: add radix_tree_split_preload()
  radix-tree: add radix_tree_split
  radix-tree: add radix_tree_join
  radix-tree: delete radix_tree_range_tag_if_tagged()
  radix-tree: delete radix_tree_locate_item()
  radix-tree: improve multiorder iterators
  btrfs: fix race in btrfs_free_dummy_fs_info()
  radix-tree: improve dump output
  radix-tree: make radix_tree_find_next_bit more useful
  ...

1 files changed, 28 insertions, 4 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index abd7403aba41..54287d443806 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -661,8 +661,8 @@ unsigned long shmem_partial_swap_usage(struct address_space *mapping,
 			swapped++;
 
 		if (need_resched()) {
+			slot = radix_tree_iter_resume(slot, &iter);
 			cond_resched_rcu();
-			slot = radix_tree_iter_next(&iter);
 		}
 	}
 
@@ -1049,6 +1049,30 @@ static void shmem_evict_inode(struct inode *inode)
 	clear_inode(inode);
 }
 
+static unsigned long find_swap_entry(struct radix_tree_root *root, void *item)
+{
+	struct radix_tree_iter iter;
+	void **slot;
+	unsigned long found = -1;
+	unsigned int checked = 0;
+
+	rcu_read_lock();
+	radix_tree_for_each_slot(slot, root, &iter, 0) {
+		if (*slot == item) {
+			found = iter.index;
+			break;
+		}
+		checked++;
+		if ((checked % 4096) != 0)
+			continue;
+		slot = radix_tree_iter_resume(slot, &iter);
+		cond_resched_rcu();
+	}
+
+	rcu_read_unlock();
+	return found;
+}
+
 /*
  * If swap found in inode, free it and move page from swapcache to filecache.
  */
@@ -1062,7 +1086,7 @@ static int shmem_unuse_inode(struct shmem_inode_info *info,
 	int error = 0;
 
 	radswap = swp_to_radix_entry(swap);
-	index = radix_tree_locate_item(&mapping->page_tree, radswap);
+	index = find_swap_entry(&mapping->page_tree, radswap);
 	if (index == -1)
 		return -EAGAIN;	/* tell shmem_unuse we found nothing */
 
@@ -2447,8 +2471,8 @@ static void shmem_tag_pins(struct address_space *mapping)
 		}
 
 		if (need_resched()) {
+			slot = radix_tree_iter_resume(slot, &iter);
 			cond_resched_rcu();
-			slot = radix_tree_iter_next(&iter);
 		}
 	}
 	rcu_read_unlock();
@@ -2517,8 +2541,8 @@ static int shmem_wait_for_pins(struct address_space *mapping)
 			spin_unlock_irq(&mapping->tree_lock);
 continue_resched:
 			if (need_resched()) {
+				slot = radix_tree_iter_resume(slot, &iter);
 				cond_resched_rcu();
-				slot = radix_tree_iter_next(&iter);
 			}
 		}
 		rcu_read_unlock();