1 files changed, 35 insertions, 105 deletions

diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
index 377be131d23b..979da17cbbf3 100644
--- a/fs/squashfs/file.c
+++ b/fs/squashfs/file.c
@@ -47,16 +47,12 @@
 #include <linux/string.h>
 #include <linux/pagemap.h>
 #include <linux/mutex.h>
-#include <linux/mm_inline.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
 
-// Backported from 4.5
-#define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
-
 /*
  * Locate cache slot in range [offset, index] for specified inode.  If
  * there's more than one return the slot closest to index.
@@ -446,21 +442,6 @@ static int squashfs_readpage_fragment(struct page *page)
 	return res;
 }
 
-static int squashfs_readpages_fragment(struct page *page,
-	struct list_head *readahead_pages, struct address_space *mapping)
-{
-	if (!page) {
-		page = lru_to_page(readahead_pages);
-		list_del(&page->lru);
-		if (add_to_page_cache_lru(page, mapping, page->index,
-			mapping_gfp_constraint(mapping, GFP_KERNEL))) {
-			put_page(page);
-			return 0;
-		}
-	}
-	return squashfs_readpage_fragment(page);
-}
-
 static int squashfs_readpage_sparse(struct page *page, int index, int file_end)
 {
 	struct inode *inode = page->mapping->host;
@@ -473,105 +454,54 @@ static int squashfs_readpage_sparse(struct page *page, int index, int file_end)
 	return 0;
 }
 
-static int squashfs_readpages_sparse(struct page *page,
-	struct list_head *readahead_pages, int index, int file_end,
-	struct address_space *mapping)
-{
-	if (!page) {
-		page = lru_to_page(readahead_pages);
-		list_del(&page->lru);
-		if (add_to_page_cache_lru(page, mapping, page->index,
-			mapping_gfp_constraint(mapping, GFP_KERNEL))) {
-			put_page(page);
-			return 0;
-		}
-	}
-	return squashfs_readpage_sparse(page, index, file_end);
-}
-
-static int __squashfs_readpages(struct file *file, struct page *page,
-	struct list_head *readahead_pages, unsigned int nr_pages,
-	struct address_space *mapping)
+static int squashfs_readpage(struct file *file, struct page *page)
 {
-	struct inode *inode = mapping->host;
+	struct inode *inode = page->mapping->host;
 	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+	int index = page->index >> (msblk->block_log - PAGE_CACHE_SHIFT);
 	int file_end = i_size_read(inode) >> msblk->block_log;
 	int res;
-
-	do {
-		struct page *cur_page = page ? page
-					     : lru_to_page(readahead_pages);
-		int page_index = cur_page->index;
-		int index = page_index >> (msblk->block_log - PAGE_CACHE_SHIFT);
-
-		if (page_index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
-						PAGE_CACHE_SHIFT))
-			return 1;
-
-		if (index < file_end || squashfs_i(inode)->fragment_block ==
-						SQUASHFS_INVALID_BLK) {
-			u64 block = 0;
-			int bsize = read_blocklist(inode, index, &block);
-
-			if (bsize < 0)
-				return -1;
-
-			if (bsize == 0) {
-				res = squashfs_readpages_sparse(page,
-					readahead_pages, index, file_end,
-					mapping);
-			} else {
-				res = squashfs_readpages_block(page,
-					readahead_pages, &nr_pages, mapping,
-					page_index, block, bsize);
-			}
-		} else {
-			res = squashfs_readpages_fragment(page,
-				readahead_pages, mapping);
-		}
-		if (res)
-			return 0;
-		page = NULL;
-	} while (readahead_pages && !list_empty(readahead_pages));
-
-	return 0;
-}
-
-static int squashfs_readpage(struct file *file, struct page *page)
-{
-	int ret;
+	void *pageaddr;
 
 	TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
-	      page->index, squashfs_i(page->mapping->host)->start);
+				page->index, squashfs_i(inode)->start);
 
-	get_page(page);
+	if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
+					PAGE_CACHE_SHIFT))
+		goto out;
 
-	ret = __squashfs_readpages(file, page, NULL, 1, page->mapping);
-	if (ret) {
-		flush_dcache_page(page);
-		if (ret < 0)
-			SetPageError(page);
-		else
-			SetPageUptodate(page);
-		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
-		unlock_page(page);
-		put_page(page);
-	}
+	if (index < file_end || squashfs_i(inode)->fragment_block ==
+					SQUASHFS_INVALID_BLK) {
+		u64 block = 0;
+		int bsize = read_blocklist(inode, index, &block);
+		if (bsize < 0)
+			goto error_out;
 
-	return 0;
-}
+		if (bsize == 0)
+			res = squashfs_readpage_sparse(page, index, file_end);
+		else
+			res = squashfs_readpage_block(page, block, bsize);
+	} else
+		res = squashfs_readpage_fragment(page);
+
+	if (!res)
+		return 0;
+
+error_out:
+	SetPageError(page);
+out:
+	pageaddr = kmap_atomic(page);
+	memset(pageaddr, 0, PAGE_CACHE_SIZE);
+	kunmap_atomic(pageaddr);
+	flush_dcache_page(page);
+	if (!PageError(page))
+		SetPageUptodate(page);
+	unlock_page(page);
 
-static int squashfs_readpages(struct file *file, struct address_space *mapping,
-			      struct list_head *pages, unsigned int nr_pages)
-{
-	TRACE("Entered squashfs_readpages, %u pages, first page index %lx\n",
-		nr_pages, lru_to_page(pages)->index);
-	__squashfs_readpages(file, NULL, pages, nr_pages, mapping);
 	return 0;
 }
 
 
 const struct address_space_operations squashfs_aops = {
-	.readpage = squashfs_readpage,
-	.readpages = squashfs_readpages,
+	.readpage = squashfs_readpage
 };