X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Ftruncate.c;h=6cb3fff25f670948d1ef519d7609793b54bfdca3;hb=944d79559d154c12becde0dab327016cf438f46c;hp=c9a63f0b69a2b4147d9c9ac0fa398c817ab3564b;hpb=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2;p=pandora-kernel.git

diff --git a/mm/truncate.c b/mm/truncate.c
index c9a63f0b69a2..6cb3fff25f67 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -13,18 +13,9 @@
 #include <linux/pagemap.h>
 #include <linux/pagevec.h>
 #include <linux/buffer_head.h>	/* grr. try_to_release_page,
-				   block_invalidatepage */
+				   do_invalidatepage */
 
 
-static int do_invalidatepage(struct page *page, unsigned long offset)
-{
-	int (*invalidatepage)(struct page *, unsigned long);
-	invalidatepage = page->mapping->a_ops->invalidatepage;
-	if (invalidatepage == NULL)
-		invalidatepage = block_invalidatepage;
-	return (*invalidatepage)(page, offset);
-}
-
 static inline void truncate_partial_page(struct page *page, unsigned partial)
 {
 	memclear_highpage_flush(page, partial, PAGE_CACHE_SIZE-partial);
@@ -91,12 +82,15 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
 }
 
 /**
- * truncate_inode_pages - truncate *all* the pages from an offset
+ * truncate_inode_pages - truncate range of pages specified by start and
+ * end byte offsets
  * @mapping: mapping to truncate
  * @lstart: offset from which to truncate
+ * @lend: offset to which to truncate
  *
- * Truncate the page cache at a set offset, removing the pages that are beyond
- * that offset (and zeroing out partial pages).
+ * Truncate the page cache, removing the pages that are between
+ * specified offsets (and zeroing out partial page
+ * (if lstart is not page aligned)).
  *
  * Truncate takes two passes - the first pass is nonblocking.  It will not
  * block on page locks and it will not block on writeback.  The second pass
@@ -110,12 +104,12 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
  * We pass down the cache-hot hint to the page freeing code.  Even if the
  * mapping is large, it is probably the case that the final pages are the most
  * recently touched, and freeing happens in ascending file offset order.
- *
- * Called under (and serialised by) inode->i_sem.
  */
-void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
+void truncate_inode_pages_range(struct address_space *mapping,
+				loff_t lstart, loff_t lend)
 {
 	const pgoff_t start = (lstart + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
+	pgoff_t end;
 	const unsigned partial = lstart & (PAGE_CACHE_SIZE - 1);
 	struct pagevec pvec;
 	pgoff_t next;
@@ -124,13 +118,22 @@ void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
 	if (mapping->nrpages == 0)
 		return;
 
+	BUG_ON((lend & (PAGE_CACHE_SIZE - 1)) != (PAGE_CACHE_SIZE - 1));
+	end = (lend >> PAGE_CACHE_SHIFT);
+
 	pagevec_init(&pvec, 0);
 	next = start;
-	while (pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
+	while (next <= end &&
+	       pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
 		for (i = 0; i < pagevec_count(&pvec); i++) {
 			struct page *page = pvec.pages[i];
 			pgoff_t page_index = page->index;
 
+			if (page_index > end) {
+				next = page_index;
+				break;
+			}
+
 			if (page_index > next)
 				next = page_index;
 			next++;
@@ -166,9 +169,15 @@ void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
 			next = start;
 			continue;
 		}
+		if (pvec.pages[0]->index > end) {
+			pagevec_release(&pvec);
+			break;
+		}
 		for (i = 0; i < pagevec_count(&pvec); i++) {
 			struct page *page = pvec.pages[i];
 
+			if (page->index > end)
+				break;
 			lock_page(page);
 			wait_on_page_writeback(page);
 			if (page->index > next)
@@ -180,7 +189,19 @@ void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
 		pagevec_release(&pvec);
 	}
 }
+EXPORT_SYMBOL(truncate_inode_pages_range);
 
+/**
+ * truncate_inode_pages - truncate *all* the pages from an offset
+ * @mapping: mapping to truncate
+ * @lstart: offset from which to truncate
+ *
+ * Called under (and serialised by) inode->i_mutex.
+ */
+void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
+{
+	truncate_inode_pages_range(mapping, lstart, (loff_t)-1);
+}
 EXPORT_SYMBOL(truncate_inode_pages);
 
 /**
@@ -228,7 +249,6 @@ unlock:
 				break;
 		}
 		pagevec_release(&pvec);
-		cond_resched();
 	}
 	return ret;
 }
@@ -242,7 +262,7 @@ EXPORT_SYMBOL(invalidate_inode_pages);
 
 /**
  * invalidate_inode_pages2_range - remove range of pages from an address_space
- * @mapping - the address_space
+ * @mapping: the address_space
  * @start: the page offset 'from' which to invalidate
  * @end: the page offset 'to' which to invalidate (inclusive)
  *
@@ -291,8 +311,8 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 					 * Zap the rest of the file in one hit.
 					 */
 					unmap_mapping_range(mapping,
-					    page_index << PAGE_CACHE_SHIFT,
-					    (end - page_index + 1)
+					   (loff_t)page_index<<PAGE_CACHE_SHIFT,
+					   (loff_t)(end - page_index + 1)
 							<< PAGE_CACHE_SHIFT,
 					    0);
 					did_range_unmap = 1;
@@ -301,7 +321,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 					 * Just zap this page
 					 */
 					unmap_mapping_range(mapping,
-					  page_index << PAGE_CACHE_SHIFT,
+					  (loff_t)page_index<<PAGE_CACHE_SHIFT,
 					  PAGE_CACHE_SIZE, 0);
 				}
 			}
@@ -322,7 +342,7 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
 
 /**
  * invalidate_inode_pages2 - remove all pages from an address_space
- * @mapping - the address_space
+ * @mapping: the address_space
  *
  * Any pages which are found to be mapped into pagetables are unmapped prior to
  * invalidation.