Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[~andy/linux] / fs / hpfs / buffer.c

diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c
index 4d0a1afa058c8a830f00e36443a2f9fed03dd0a3..139ef1684d074bba059ff0c401f65273420e7c6a 100644 (file)
--- a/fs/hpfs/buffer.c
+++ b/fs/hpfs/buffer.c
@@ -86,7 +86,6 @@ void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head
 void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
                   int ahead)
 {
-       struct buffer_head *bh;
        char *data;
 
        hpfs_lock_assert(s);
@@ -100,34 +99,32 @@ void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffe
 
        hpfs_prefetch_sectors(s, secno, 4 + ahead);
 
+       if (!(qbh->bh[0] = sb_bread(s, secno + 0))) goto bail0;
+       if (!(qbh->bh[1] = sb_bread(s, secno + 1))) goto bail1;
+       if (!(qbh->bh[2] = sb_bread(s, secno + 2))) goto bail2;
+       if (!(qbh->bh[3] = sb_bread(s, secno + 3))) goto bail3;
+
+       if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
+           likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
+           likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
+               return qbh->data = qbh->bh[0]->b_data;
+       }
+
        qbh->data = data = kmalloc(2048, GFP_NOFS);
        if (!data) {
                printk("HPFS: hpfs_map_4sectors: out of memory\n");
-               goto bail;
+               goto bail4;
        }
 
-       qbh->bh[0] = bh = sb_bread(s, secno);
-       if (!bh)
-               goto bail0;
-       memcpy(data, bh->b_data, 512);
-
-       qbh->bh[1] = bh = sb_bread(s, secno + 1);
-       if (!bh)
-               goto bail1;
-       memcpy(data + 512, bh->b_data, 512);
-
-       qbh->bh[2] = bh = sb_bread(s, secno + 2);
-       if (!bh)
-               goto bail2;
-       memcpy(data + 2 * 512, bh->b_data, 512);
-
-       qbh->bh[3] = bh = sb_bread(s, secno + 3);
-       if (!bh)
-               goto bail3;
-       memcpy(data + 3 * 512, bh->b_data, 512);
+       memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512);
+       memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512);
+       memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512);
+       memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512);
 
        return data;
 
+ bail4:
+       brelse(qbh->bh[3]);
  bail3:
        brelse(qbh->bh[2]);
  bail2:
@@ -135,9 +132,6 @@ void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffe
  bail1:
        brelse(qbh->bh[0]);
  bail0:
-       kfree(data);
-       printk("HPFS: hpfs_map_4sectors: read error\n");
- bail:
        return NULL;
 }
 
@@ -155,44 +149,54 @@ void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
                return NULL;
        }
 
-       /*return hpfs_map_4sectors(s, secno, qbh, 0);*/
+       if (!hpfs_get_sector(s, secno + 0, &qbh->bh[0])) goto bail0;
+       if (!hpfs_get_sector(s, secno + 1, &qbh->bh[1])) goto bail1;
+       if (!hpfs_get_sector(s, secno + 2, &qbh->bh[2])) goto bail2;
+       if (!hpfs_get_sector(s, secno + 3, &qbh->bh[3])) goto bail3;
+
+       if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
+           likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
+           likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
+               return qbh->data = qbh->bh[0]->b_data;
+       }
+
        if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
                printk("HPFS: hpfs_get_4sectors: out of memory\n");
-               return NULL;
+               goto bail4;
        }
-       if (!(hpfs_get_sector(s, secno, &qbh->bh[0]))) goto bail0;
-       if (!(hpfs_get_sector(s, secno + 1, &qbh->bh[1]))) goto bail1;
-       if (!(hpfs_get_sector(s, secno + 2, &qbh->bh[2]))) goto bail2;
-       if (!(hpfs_get_sector(s, secno + 3, &qbh->bh[3]))) goto bail3;
-       memcpy(qbh->data, qbh->bh[0]->b_data, 512);
-       memcpy(qbh->data + 512, qbh->bh[1]->b_data, 512);
-       memcpy(qbh->data + 2*512, qbh->bh[2]->b_data, 512);
-       memcpy(qbh->data + 3*512, qbh->bh[3]->b_data, 512);
        return qbh->data;
 
-       bail3:  brelse(qbh->bh[2]);
-       bail2:  brelse(qbh->bh[1]);
-       bail1:  brelse(qbh->bh[0]);
-       bail0:
+bail4:
+       brelse(qbh->bh[3]);
+bail3:
+       brelse(qbh->bh[2]);
+bail2:
+       brelse(qbh->bh[1]);
+bail1:
+       brelse(qbh->bh[0]);
+bail0:
        return NULL;
 }
        
 
 void hpfs_brelse4(struct quad_buffer_head *qbh)
 {
-       brelse(qbh->bh[3]);
-       brelse(qbh->bh[2]);
-       brelse(qbh->bh[1]);
+       if (unlikely(qbh->data != qbh->bh[0]->b_data))
+               kfree(qbh->data);
        brelse(qbh->bh[0]);
-       kfree(qbh->data);
+       brelse(qbh->bh[1]);
+       brelse(qbh->bh[2]);
+       brelse(qbh->bh[3]);
 }      
 
 void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
 {
-       memcpy(qbh->bh[0]->b_data, qbh->data, 512);
-       memcpy(qbh->bh[1]->b_data, qbh->data + 512, 512);
-       memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
-       memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
+       if (unlikely(qbh->data != qbh->bh[0]->b_data)) {
+               memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512);
+               memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 512, 512);
+               memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
+               memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
+       }
        mark_buffer_dirty(qbh->bh[0]);
        mark_buffer_dirty(qbh->bh[1]);
        mark_buffer_dirty(qbh->bh[2]);