hpfs: use mpage

Use the mpage interface to improve performance.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hpfs/file.c

@@ -7,6 +7,7 @@
  */
 
 #include "hpfs_fn.h"
+#include <linux/mpage.h>
 
 #define BLOCKS(size) (((size) + 511) >> 9)
 
@@ -34,7 +35,7 @@ int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  * so we must ignore such errors.
  */
 
-static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
+static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs)
 {
 	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
 	unsigned n, disk_secno;
@@ -42,11 +43,20 @@ static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
 	struct buffer_head *bh;
 	if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
 	n = file_secno - hpfs_inode->i_file_sec;
-	if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n;
+	if (n < hpfs_inode->i_n_secs) {
+		*n_secs = hpfs_inode->i_n_secs - n;
+		return hpfs_inode->i_disk_sec + n;
+	}
 	if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
 	disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
 	if (disk_secno == -1) return 0;
 	if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
+	n = file_secno - hpfs_inode->i_file_sec;
+	if (n < hpfs_inode->i_n_secs) {
+		*n_secs = hpfs_inode->i_n_secs - n;
+		return hpfs_inode->i_disk_sec + n;
+	}
+	*n_secs = 1;
 	return disk_secno;
 }
 
@@ -67,10 +77,14 @@ static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_he
 {
 	int r;
 	secno s;
+	unsigned n_secs;
 	hpfs_lock(inode->i_sb);
-	s = hpfs_bmap(inode, iblock);
+	s = hpfs_bmap(inode, iblock, &n_secs);
 	if (s) {
+		if (bh_result->b_size >> 9 < n_secs)
+			n_secs = bh_result->b_size >> 9;
 		map_bh(bh_result, inode->i_sb, s);
+		bh_result->b_size = n_secs << 9;
 		goto ret_0;
 	}
 	if (!create) goto ret_0;
@@ -95,14 +109,26 @@ static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_he
 	return r;
 }
 
+static int hpfs_readpage(struct file *file, struct page *page)
+{
+	return mpage_readpage(page, hpfs_get_block);
+}
+
 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
 {
-	return block_write_full_page(page,hpfs_get_block, wbc);
+	return block_write_full_page(page, hpfs_get_block, wbc);
 }
 
-static int hpfs_readpage(struct file *file, struct page *page)
+static int hpfs_readpages(struct file *file, struct address_space *mapping,
+			  struct list_head *pages, unsigned nr_pages)
+{
+	return mpage_readpages(mapping, pages, nr_pages, hpfs_get_block);
+}
+
+static int hpfs_writepages(struct address_space *mapping,
+			   struct writeback_control *wbc)
 {
-	return block_read_full_page(page,hpfs_get_block);
+	return mpage_writepages(mapping, wbc, hpfs_get_block);
 }
 
 static void hpfs_write_failed(struct address_space *mapping, loff_t to)
@@ -161,6 +187,8 @@ static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
 const struct address_space_operations hpfs_aops = {
 	.readpage = hpfs_readpage,
 	.writepage = hpfs_writepage,
+	.readpages = hpfs_readpages,
+	.writepages = hpfs_writepages,
 	.write_begin = hpfs_write_begin,
 	.write_end = hpfs_write_end,
 	.bmap = _hpfs_bmap