HWPOISON: Refactor truncate to allow direct truncating of page v2

Extract out truncate_inode_page() out of the truncate path so that it can be used by memory-failure.c [AK: description, headers, fix typos] v2: Some white space changes from Fengguang Wu Signed-off-by: Andi Kleen <ak@linux.intel.com>

HWPOISON: Refactor truncate to allow direct truncating of page v2
Extract out truncate_inode_page() out of the truncate path so that it can be used by memory-failure.c [AK: description, headers, fix typos] v2: Some white space changes from Fengguang Wu Signed-off-by: Andi Kleen <ak@linux.intel.com>
Nick Piggin · Andi Kleen
1 parent 2a7684a23e
Showing 2 changed files with 17 additions and 14 deletions Side-by-side Diff
include/linux/mm.h
mm/truncate.c
@@ -794,6 +794,8 @@
 extern int vmtruncate(struct inode * inode, loff_t offset);
 extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
  
+int truncate_inode_page(struct address_space *mapping, struct page *page);
+
 #ifdef CONFIG_MMU
 extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 			unsigned long address, unsigned int flags);
@@ -93,11 +93,11 @@
  * its lock, b) when a concurrent invalidate_mapping_pages got there first and
  * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
  */
-static void
+static int
 truncate_complete_page(struct address_space *mapping, struct page *page)
 {
 	if (page->mapping != mapping)
-		return;
+		return -EIO;
  
 	if (page_has_private(page))
 		do_invalidatepage(page, 0);
@@ -108,6 +108,7 @@
 	remove_from_page_cache(page);
 	ClearPageMappedToDisk(page);
 	page_cache_release(page);	/* pagecache ref */
+	return 0;
 }
  
 /*
@@ -135,6 +136,16 @@
 	return ret;
 }
  
+int truncate_inode_page(struct address_space *mapping, struct page *page)
+{
+	if (page_mapped(page)) {
+		unmap_mapping_range(mapping,
+				   (loff_t)page->index << PAGE_CACHE_SHIFT,
+				   PAGE_CACHE_SIZE, 0);
+	}
+	return truncate_complete_page(mapping, page);
+}
+
 /**
  * truncate_inode_pages - truncate range of pages specified by start & end byte offsets
  * @mapping: mapping to truncate
@@ -196,12 +207,7 @@
 				unlock_page(page);
 				continue;
 			}
-			if (page_mapped(page)) {
-				unmap_mapping_range(mapping,
-				  (loff_t)page_index<<PAGE_CACHE_SHIFT,
-				  PAGE_CACHE_SIZE, 0);
-			}
-			truncate_complete_page(mapping, page);
+			truncate_inode_page(mapping, page);
 			unlock_page(page);
 		}
 		pagevec_release(&pvec);
  
@@ -238,15 +244,10 @@
 				break;
 			lock_page(page);
 			wait_on_page_writeback(page);
-			if (page_mapped(page)) {
-				unmap_mapping_range(mapping,
-				  (loff_t)page->index<<PAGE_CACHE_SHIFT,
-				  PAGE_CACHE_SIZE, 0);
-			}
+			truncate_inode_page(mapping, page);
 			if (page->index > next)
 				next = page->index;
 			next++;
-			truncate_complete_page(mapping, page);
 			unlock_page(page);
 		}
 		pagevec_release(&pvec);
...	...	@@ -794,6 +794,8 @@
794	794	extern int vmtruncate(struct inode * inode, loff_t offset);
795	795	extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
796	796
	797	+int truncate_inode_page(struct address_space mapping, struct page page);
	798	+
797	799	#ifdef CONFIG_MMU
798	800	extern int handle_mm_fault(struct mm_struct mm, struct vm_area_struct vma,
799	801	unsigned long address, unsigned int flags);
...	...	@@ -93,11 +93,11 @@
93	93	* its lock, b) when a concurrent invalidate_mapping_pages got there first and
94	94	* c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
95	95	*/
96		-static void
	96	+static int
97	97	truncate_complete_page(struct address_space mapping, struct page page)
98	98	{
99	99	if (page->mapping != mapping)
100		- return;
	100	+ return -EIO;
101	101
102	102	if (page_has_private(page))
103	103	do_invalidatepage(page, 0);
...	...	@@ -108,6 +108,7 @@
108	108	remove_from_page_cache(page);
109	109	ClearPageMappedToDisk(page);
110	110	page_cache_release(page); /* pagecache ref */
	111	+ return 0;
111	112	}
112	113
113	114	/*
...	...	@@ -135,6 +136,16 @@
135	136	return ret;
136	137	}
137	138
	139	+int truncate_inode_page(struct address_space mapping, struct page page)
	140	+{
	141	+ if (page_mapped(page)) {
	142	+ unmap_mapping_range(mapping,
	143	+ (loff_t)page->index << PAGE_CACHE_SHIFT,
	144	+ PAGE_CACHE_SIZE, 0);
	145	+ }
	146	+ return truncate_complete_page(mapping, page);
	147	+}
	148	+
138	149	/**
139	150	* truncate_inode_pages - truncate range of pages specified by start & end byte offsets
140	151	* @mapping: mapping to truncate
...	...	@@ -196,12 +207,7 @@
196	207	unlock_page(page);
197	208	continue;
198	209	}
199		- if (page_mapped(page)) {
200		- unmap_mapping_range(mapping,
201		- (loff_t)page_index<<PAGE_CACHE_SHIFT,
202		- PAGE_CACHE_SIZE, 0);
203		- }
204		- truncate_complete_page(mapping, page);
	210	+ truncate_inode_page(mapping, page);
205	211	unlock_page(page);
206	212	}
207	213	pagevec_release(&pvec);
208	214
...	...	@@ -238,15 +244,10 @@
238	244	break;
239	245	lock_page(page);
240	246	wait_on_page_writeback(page);
241		- if (page_mapped(page)) {
242		- unmap_mapping_range(mapping,
243		- (loff_t)page->index<<PAGE_CACHE_SHIFT,
244		- PAGE_CACHE_SIZE, 0);
245		- }
	247	+ truncate_inode_page(mapping, page);
246	248	if (page->index > next)
247	249	next = page->index;
248	250	next++;
249		- truncate_complete_page(mapping, page);
250	251	unlock_page(page);
251	252	}
252	253	pagevec_release(&pvec);