fs/hpfs/buffer.c

   1 /*
   2  *  linux/fs/hpfs/buffer.c
   3  *
   4  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
   5  *
   6  *  general buffer i/o
   7  */
   8 #include <linux/sched.h>
   9 #include <linux/slab.h>
  10 #include "hpfs_fn.h"
  11
  12 void hpfs_lock_creation(struct super_block *s)
  13 {
  14 #ifdef DEBUG_LOCKS
  15         printk("lock creation\n");
  16 #endif
  17         down(&hpfs_sb(s)->hpfs_creation_de);
  18 }
  19
  20 void hpfs_unlock_creation(struct super_block *s)
  21 {
  22 #ifdef DEBUG_LOCKS
  23         printk("unlock creation\n");
  24 #endif
  25         up(&hpfs_sb(s)->hpfs_creation_de);
  26 }
  27
  28 /* Map a sector into a buffer and return pointers to it and to the buffer. */
  29
  30 void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
  31                  int ahead)
  32 {
  33         struct buffer_head *bh;
  34
  35         cond_resched();
  36
  37         *bhp = bh = sb_bread(s, secno);
  38         if (bh != NULL)
  39                 return bh->b_data;
  40         else {
  41                 printk("HPFS: hpfs_map_sector: read error\n");
  42                 return NULL;
  43         }
  44 }
  45
  46 /* Like hpfs_map_sector but don't read anything */
  47
  48 void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
  49 {
  50         struct buffer_head *bh;
  51         /*return hpfs_map_sector(s, secno, bhp, 0);*/
  52
  53         cond_resched();
  54
  55         if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
  56                 if (!buffer_uptodate(bh)) wait_on_buffer(bh);
  57                 set_buffer_uptodate(bh);
  58                 return bh->b_data;
  59         } else {
  60                 printk("HPFS: hpfs_get_sector: getblk failed\n");
  61                 return NULL;
  62         }
  63 }
  64
  65 /* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
  66
  67 void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
  68                    int ahead)
  69 {
  70         struct buffer_head *bh;
  71         char *data;
  72
  73         cond_resched();
  74
  75         if (secno & 3) {
  76                 printk("HPFS: hpfs_map_4sectors: unaligned read\n");
  77                 return NULL;
  78         }
  79
  80         qbh->data = data = kmalloc(2048, GFP_NOFS);
  81         if (!data) {
  82                 printk("HPFS: hpfs_map_4sectors: out of memory\n");
  83                 goto bail;
  84         }
  85
  86         qbh->bh[0] = bh = sb_bread(s, secno);
  87         if (!bh)
  88                 goto bail0;
  89         memcpy(data, bh->b_data, 512);
  90
  91         qbh->bh[1] = bh = sb_bread(s, secno + 1);
  92         if (!bh)
  93                 goto bail1;
  94         memcpy(data + 512, bh->b_data, 512);
  95
  96         qbh->bh[2] = bh = sb_bread(s, secno + 2);
  97         if (!bh)
  98                 goto bail2;
  99         memcpy(data + 2 * 512, bh->b_data, 512);
 100
 101         qbh->bh[3] = bh = sb_bread(s, secno + 3);
 102         if (!bh)
 103                 goto bail3;
 104         memcpy(data + 3 * 512, bh->b_data, 512);
 105
 106         return data;
 107
 108  bail3:
 109         brelse(qbh->bh[2]);
 110  bail2:
 111         brelse(qbh->bh[1]);
 112  bail1:
 113         brelse(qbh->bh[0]);
 114  bail0:
 115         kfree(data);
 116         printk("HPFS: hpfs_map_4sectors: read error\n");
 117  bail:
 118         return NULL;
 119 }
 120
 121 /* Don't read sectors */
 122
 123 void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
 124                           struct quad_buffer_head *qbh)
 125 {
 126         cond_resched();
 127
 128         if (secno & 3) {
 129                 printk("HPFS: hpfs_get_4sectors: unaligned read\n");
 130                 return NULL;
 131         }
 132
 133         /*return hpfs_map_4sectors(s, secno, qbh, 0);*/
 134         if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
 135                 printk("HPFS: hpfs_get_4sectors: out of memory\n");
 136                 return NULL;
 137         }
 138         if (!(hpfs_get_sector(s, secno, &qbh->bh[0]))) goto bail0;
 139         if (!(hpfs_get_sector(s, secno + 1, &qbh->bh[1]))) goto bail1;
 140         if (!(hpfs_get_sector(s, secno + 2, &qbh->bh[2]))) goto bail2;
 141         if (!(hpfs_get_sector(s, secno + 3, &qbh->bh[3]))) goto bail3;
 142         memcpy(qbh->data, qbh->bh[0]->b_data, 512);
 143         memcpy(qbh->data + 512, qbh->bh[1]->b_data, 512);
 144         memcpy(qbh->data + 2*512, qbh->bh[2]->b_data, 512);
 145         memcpy(qbh->data + 3*512, qbh->bh[3]->b_data, 512);
 146         return qbh->data;
 147
 148         bail3:  brelse(qbh->bh[2]);
 149         bail2:  brelse(qbh->bh[1]);
 150         bail1:  brelse(qbh->bh[0]);
 151         bail0:
 152         return NULL;
 153 }
 154
 155
 156 void hpfs_brelse4(struct quad_buffer_head *qbh)
 157 {
 158         brelse(qbh->bh[3]);
 159         brelse(qbh->bh[2]);
 160         brelse(qbh->bh[1]);
 161         brelse(qbh->bh[0]);
 162         kfree(qbh->data);
 163 }
 164
 165 void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
 166 {
 167         PRINTK(("hpfs_mark_4buffers_dirty\n"));
 168         memcpy(qbh->bh[0]->b_data, qbh->data, 512);
 169         memcpy(qbh->bh[1]->b_data, qbh->data + 512, 512);
 170         memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
 171         memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
 172         mark_buffer_dirty(qbh->bh[0]);
 173         mark_buffer_dirty(qbh->bh[1]);
 174         mark_buffer_dirty(qbh->bh[2]);
 175         mark_buffer_dirty(qbh->bh[3]);
 176 }