Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 46 insertions, 6 deletions

diff --git a/mm/truncate.c b/mm/truncate.c
index 632b15e29f7..61a183b89df 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -52,7 +52,7 @@ void do_invalidatepage(struct page *page, unsigned long offset)
 static inline void truncate_partial_page(struct page *page, unsigned partial)
 {
 	zero_user_segment(page, partial, PAGE_CACHE_SIZE);
-	cleancache_flush_page(page->mapping, page);
+	cleancache_invalidate_page(page->mapping, page);
 	if (page_has_private(page))
 		do_invalidatepage(page, partial);
 }
@@ -184,7 +184,7 @@ int invalidate_inode_page(struct page *page)
 }
 
 /**
- * truncate_inode_pages - truncate range of pages specified by start & end byte offsets
+ * truncate_inode_pages_range - truncate range of pages specified by start & end byte offsets
  * @mapping: mapping to truncate
  * @lstart: offset from which to truncate
  * @lend: offset to which to truncate
@@ -213,7 +213,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
 	pgoff_t end;
 	int i;
 
-	cleancache_flush_inode(mapping);
+	cleancache_invalidate_inode(mapping);
 	if (mapping->nrpages == 0)
 		return;
 
@@ -292,7 +292,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
 		mem_cgroup_uncharge_end();
 		index++;
 	}
-	cleancache_flush_inode(mapping);
+	cleancache_invalidate_inode(mapping);
 }
 EXPORT_SYMBOL(truncate_inode_pages_range);
 
@@ -444,7 +444,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 	int ret2 = 0;
 	int did_range_unmap = 0;
 
-	cleancache_flush_inode(mapping);
+	cleancache_invalidate_inode(mapping);
 	pagevec_init(&pvec, 0);
 	index = start;
 	while (index <= end && pagevec_lookup(&pvec, mapping, index,
@@ -500,7 +500,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 		cond_resched();
 		index++;
 	}
-	cleancache_flush_inode(mapping);
+	cleancache_invalidate_inode(mapping);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
@@ -626,3 +626,43 @@ int vmtruncate_range(struct inode *inode, loff_t lstart, loff_t lend)
 
 	return 0;
 }
+
+/**
+ * truncate_pagecache_range - unmap and remove pagecache that is hole-punched
+ * @inode: inode
+ * @lstart: offset of beginning of hole
+ * @lend: offset of last byte of hole
+ *
+ * This function should typically be called before the filesystem
+ * releases resources associated with the freed range (eg. deallocates
+ * blocks). This way, pagecache will always stay logically coherent
+ * with on-disk format, and the filesystem would not have to deal with
+ * situations such as writepage being called for a page that has already
+ * had its underlying blocks deallocated.
+ */
+void truncate_pagecache_range(struct inode *inode, loff_t lstart, loff_t lend)
+{
+	struct address_space *mapping = inode->i_mapping;
+	loff_t unmap_start = round_up(lstart, PAGE_SIZE);
+	loff_t unmap_end = round_down(1 + lend, PAGE_SIZE) - 1;
+	/*
+	 * This rounding is currently just for example: unmap_mapping_range
+	 * expands its hole outwards, whereas we want it to contract the hole
+	 * inwards.  However, existing callers of truncate_pagecache_range are
+	 * doing their own page rounding first; and truncate_inode_pages_range
+	 * currently BUGs if lend is not pagealigned-1 (it handles partial
+	 * page at start of hole, but not partial page at end of hole).  Note
+	 * unmap_mapping_range allows holelen 0 for all, and we allow lend -1.
+	 */
+
+	/*
+	 * Unlike in truncate_pagecache, unmap_mapping_range is called only
+	 * once (before truncating pagecache), and without "even_cows" flag:
+	 * hole-punching should not remove private COWed pages from the hole.
+	 */
+	if ((u64)unmap_end > (u64)unmap_start)
+		unmap_mapping_range(mapping, unmap_start,
+				    1 + unmap_end - unmap_start, 0);
+	truncate_inode_pages_range(mapping, lstart, lend);
+}
+EXPORT_SYMBOL(truncate_pagecache_range);