Merge branch 'hpfs' from Mikulas Patocka

Merge hpfs patches from Mikulas Patocka.

* emailed patches from Mikulas Patocka <mpatocka@artax.karlin.mff.cuni.cz>:
  hpfs: implement prefetch to improve performance
  hpfs: use mpage
  hpfs: better test for errors

5 files changed, 106 insertions, 13 deletions

diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c
index f49d149..4d0a1af 100644
--- a/fs/hpfs/buffer.c
+++ b/fs/hpfs/buffer.c
@@ -7,8 +7,37 @@
  */
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/blkdev.h>
 #include "hpfs_fn.h"
 
+void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n)
+{
+	struct buffer_head *bh;
+	struct blk_plug plug;
+
+	if (n <= 0 || unlikely(secno >= hpfs_sb(s)->sb_fs_size))
+		return;
+
+	bh = sb_find_get_block(s, secno);
+	if (bh) {
+		if (buffer_uptodate(bh)) {
+			brelse(bh);
+			return;
+		}
+		brelse(bh);
+	};
+
+	blk_start_plug(&plug);
+	while (n > 0) {
+		if (unlikely(secno >= hpfs_sb(s)->sb_fs_size))
+			break;
+		sb_breadahead(s, secno);
+		secno++;
+		n--;
+	}
+	blk_finish_plug(&plug);
+}
+
 /* Map a sector into a buffer and return pointers to it and to the buffer. */
 
 void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
@@ -18,6 +47,8 @@ void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head
 
 	hpfs_lock_assert(s);
 
+	hpfs_prefetch_sectors(s, secno, ahead);
+
 	cond_resched();
 
 	*bhp = bh = sb_bread(s, secno);
@@ -67,6 +98,8 @@ void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffe
 		return NULL;
 	}
 
+	hpfs_prefetch_sectors(s, secno, 4 + ahead);
+
 	qbh->data = data = kmalloc(2048, GFP_NOFS);
 	if (!data) {
 		printk("HPFS: hpfs_map_4sectors: out of memory\n");
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index e4ba5fe..4e9dabc 100644
--- a/fs/hpfs/file.c
+++ b/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
diff --git a/fs/hpfs/hpfs_fn.h b/fs/hpfs/hpfs_fn.h
index b7ae286..1b39863 100644
--- a/fs/hpfs/hpfs_fn.h
+++ b/fs/hpfs/hpfs_fn.h
@@ -27,8 +27,9 @@
 #define ALLOC_FWD_MAX	128
 #define ALLOC_M		1
 #define FNODE_RD_AHEAD	16
-#define ANODE_RD_AHEAD	16
-#define DNODE_RD_AHEAD	4
+#define ANODE_RD_AHEAD	0
+#define DNODE_RD_AHEAD	72
+#define COUNT_RD_AHEAD	62
 
 #define FREE_DNODES_ADD	58
 #define FREE_DNODES_DEL	29
@@ -207,6 +208,7 @@ void hpfs_remove_fnode(struct super_block *, fnode_secno fno);
 
 /* buffer.c */
 
+void hpfs_prefetch_sectors(struct super_block *, unsigned, int);
 void *hpfs_map_sector(struct super_block *, unsigned, struct buffer_head **, int);
 void *hpfs_get_sector(struct super_block *, unsigned, struct buffer_head **);
 void *hpfs_map_4sectors(struct super_block *, unsigned, struct quad_buffer_head *, int);
@@ -271,6 +273,7 @@ void hpfs_evict_inode(struct inode *);
 
 __le32 *hpfs_map_dnode_bitmap(struct super_block *, struct quad_buffer_head *);
 __le32 *hpfs_map_bitmap(struct super_block *, unsigned, struct quad_buffer_head *, char *);
+void hpfs_prefetch_bitmap(struct super_block *, unsigned);
 unsigned char *hpfs_load_code_page(struct super_block *, secno);
 __le32 *hpfs_load_bitmap_directory(struct super_block *, secno bmp);
 struct fnode *hpfs_map_fnode(struct super_block *s, ino_t, struct buffer_head **);
diff --git a/fs/hpfs/map.c b/fs/hpfs/map.c
index 4acb19d..3aa66ae 100644
--- a/fs/hpfs/map.c
+++ b/fs/hpfs/map.c
@@ -17,7 +17,9 @@ __le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,
 			 struct quad_buffer_head *qbh, char *id)
 {
 	secno sec;
-	if (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) {
+	__le32 *ret;
+	unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
+	if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) {
 		hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
 		return NULL;
 	}
@@ -26,7 +28,23 @@ __le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,
 		hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);
 		return NULL;
 	}
-	return hpfs_map_4sectors(s, sec, qbh, 4);
+	ret = hpfs_map_4sectors(s, sec, qbh, 4);
+	if (ret) hpfs_prefetch_bitmap(s, bmp_block + 1);
+	return ret;
+}
+
+void hpfs_prefetch_bitmap(struct super_block *s, unsigned bmp_block)
+{
+	unsigned to_prefetch, next_prefetch;
+	unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
+	if (unlikely(bmp_block >= n_bands))
+		return;
+	to_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);
+	if (unlikely(bmp_block + 1 >= n_bands))
+		next_prefetch = 0;
+	else
+		next_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block + 1]);
+	hpfs_prefetch_sectors(s, to_prefetch, 4 + 4 * (to_prefetch + 4 == next_prefetch));
 }
 
 /*
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
index a0617e7..4334cda 100644
--- a/fs/hpfs/super.c
+++ b/fs/hpfs/super.c
@@ -121,7 +121,7 @@ unsigned hpfs_count_one_bitmap(struct super_block *s, secno secno)
 	unsigned long *bits;
 	unsigned count;
 
-	bits = hpfs_map_4sectors(s, secno, &qbh, 4);
+	bits = hpfs_map_4sectors(s, secno, &qbh, 0);
 	if (!bits)
 		return 0;
 	count = bitmap_weight(bits, 2048 * BITS_PER_BYTE);
@@ -134,8 +134,13 @@ static unsigned count_bitmaps(struct super_block *s)
 	unsigned n, count, n_bands;
 	n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
 	count = 0;
-	for (n = 0; n < n_bands; n++)
+	for (n = 0; n < COUNT_RD_AHEAD; n++) {
+		hpfs_prefetch_bitmap(s, n);
+	}
+	for (n = 0; n < n_bands; n++) {
+		hpfs_prefetch_bitmap(s, n + COUNT_RD_AHEAD);
 		count += hpfs_count_one_bitmap(s, le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[n]));
+	}
 	return count;
 }
 
@@ -558,7 +563,13 @@ static int hpfs_fill_super(struct super_block *s, void *options, int silent)
 	sbi->sb_cp_table = NULL;
 	sbi->sb_c_bitmap = -1;
 	sbi->sb_max_fwd_alloc = 0xffffff;
-	
+
+	if (sbi->sb_fs_size >= 0x80000000) {
+		hpfs_error(s, "invalid size in superblock: %08x",
+			(unsigned)sbi->sb_fs_size);
+		goto bail4;
+	}
+
 	/* Load bitmap directory */
 	if (!(sbi->sb_bmp_dir = hpfs_load_bitmap_directory(s, le32_to_cpu(superblock->bitmaps))))
 		goto bail4;