Subject: + lib-radix-tree-radix_tree_delete_item.patch added to -mm tree
To: hannes@xxxxxxxxxxx,aarcange@xxxxxxxxxx,bob.liu@xxxxxxxxxx,david@xxxxxxxxxxxxx,gthelen@xxxxxxxxxx,hch@xxxxxxxxxxxxx,hughd@xxxxxxxxxx,jack@xxxxxxx,klamm@xxxxxxxxxxxxxx,kosaki.motohiro@xxxxxxxxxxxxxx,metin@xxxxxxxxxxxxx,mgorman@xxxxxxx,minchan@xxxxxxxxxx,ozgun@xxxxxxxxxxxxx,peterz@xxxxxxxxxxxxx,riel@xxxxxxxxxx,rmallon@xxxxxxxxx,semenzato@xxxxxxxxxx,tj@xxxxxxxxxx,vbabka@xxxxxxx,walken@xxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 04 Feb 2014 15:14:42 -0800
The patch titled
Subject: lib: radix-tree: add radix_tree_delete_item()
has been added to the -mm tree. Its filename is
lib-radix-tree-radix_tree_delete_item.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/lib-radix-tree-radix_tree_delete_item.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/lib-radix-tree-radix_tree_delete_item.patch
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------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: lib: radix-tree: add radix_tree_delete_item()
Provide a function that does not just delete an entry at a given index,
but also allows passing in an expected item. Delete only if that item is
still located at the specified index.
This is handy when lockless tree traversals want to delete entries as well
because they don't have to do an second, locked lookup to verify the slot
has not changed under them before deleting the entry.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan@xxxxxxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Bob Liu <bob.liu@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Greg Thelen <gthelen@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Luigi Semenzato <semenzato@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Metin Doslu <metin@xxxxxxxxxxxxx>
Cc: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Ozgun Erdogan <ozgun@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Roman Gushchin <klamm@xxxxxxxxxxxxxx>
Cc: Ryan Mallon <rmallon@xxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/radix-tree.h | 1 +
lib/radix-tree.c | 31 +++++++++++++++++++++++++++----
2 files changed, 28 insertions(+), 4 deletions(-)
diff -puN include/linux/radix-tree.h~lib-radix-tree-radix_tree_delete_item include/linux/radix-tree.h
--- a/include/linux/radix-tree.h~lib-radix-tree-radix_tree_delete_item
+++ a/include/linux/radix-tree.h
@@ -219,6 +219,7 @@ static inline void radix_tree_replace_sl
int radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
void *radix_tree_lookup(struct radix_tree_root *, unsigned long);
void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long);
+void *radix_tree_delete_item(struct radix_tree_root *, unsigned long, void *);
void *radix_tree_delete(struct radix_tree_root *, unsigned long);
unsigned int
radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
diff -puN lib/radix-tree.c~lib-radix-tree-radix_tree_delete_item lib/radix-tree.c
--- a/lib/radix-tree.c~lib-radix-tree-radix_tree_delete_item
+++ a/lib/radix-tree.c
@@ -1335,15 +1335,18 @@ static inline void radix_tree_shrink(str
}
/**
- * radix_tree_delete - delete an item from a radix tree
+ * radix_tree_delete_item - delete an item from a radix tree
* @root: radix tree root
* @index: index key
+ * @item: expected item
*
- * Remove the item at @index from the radix tree rooted at @root.
+ * Remove @item at @index from the radix tree rooted at @root.
*
- * Returns the address of the deleted item, or NULL if it was not present.
+ * Returns the address of the deleted item, or NULL if it was not present
+ * or the entry at the given @index was not @item.
*/
-void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
+void *radix_tree_delete_item(struct radix_tree_root *root,
+ unsigned long index, void *item)
{
struct radix_tree_node *node = NULL;
struct radix_tree_node *slot = NULL;
@@ -1378,6 +1381,11 @@ void *radix_tree_delete(struct radix_tre
if (slot == NULL)
goto out;
+ if (item && slot != item) {
+ slot = NULL;
+ goto out;
+ }
+
/*
* Clear all tags associated with the item to be deleted.
* This way of doing it would be inefficient, but seldom is any set.
@@ -1422,6 +1430,21 @@ void *radix_tree_delete(struct radix_tre
out:
return slot;
}
+EXPORT_SYMBOL(radix_tree_delete_item);
+
+/**
+ * radix_tree_delete - delete an item from a radix tree
+ * @root: radix tree root
+ * @index: index key
+ *
+ * Remove the item at @index from the radix tree rooted at @root.
+ *
+ * Returns the address of the deleted item, or NULL if it was not present.
+ */
+void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
+{
+ return radix_tree_delete_item(root, index, NULL);
+}
EXPORT_SYMBOL(radix_tree_delete);
/**
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-vmscan-respect-numa-policy-mask-when-shrinking-slab-on-direct-reclaim.patch
mm-vmscan-move-call-to-shrink_slab-to-shrink_zones.patch
mm-vmscan-remove-shrink_control-arg-from-do_try_to_free_pages.patch
mm-vmstat-fix-up-zone-state-accounting.patch
fs-cachefiles-use-add_to_page_cache_lru.patch
lib-radix-tree-radix_tree_delete_item.patch
mm-shmem-save-one-radix-tree-lookup-when-truncating-swapped-pages.patch
mm-filemap-move-radix-tree-hole-searching-here.patch
mm-fs-prepare-for-non-page-entries-in-page-cache-radix-trees.patch
mm-fs-store-shadow-entries-in-page-cache.patch
mm-thrash-detection-based-file-cache-sizing.patch
lib-radix_tree-tree-node-interface.patch
mm-keep-page-cache-radix-tree-nodes-in-check.patch
linux-next.patch
debugging-keep-track-of-page-owners.patch
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