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 f49d1498aa2e..4d0a1afa058c 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 e4ba5fe4c3b5..4e9dabcf1f4c 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 b7ae286646b5..1b398636e990 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 4acb19d78359..3aa66ae1031e 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 a0617e706957..4334cda8dba1 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;