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   1 /*
   2  *  linux/fs/ufs/util.c
   3  *
   4  * Copyright (C) 1998
   5  * Daniel Pirkl <daniel.pirkl@email.cz>
   6  * Charles University, Faculty of Mathematics and Physics
   7  */
   8
   9 #include <linux/string.h>
  10 #include <linux/slab.h>
  11 #include <linux/ufs_fs.h>
  12 #include <linux/buffer_head.h>
  13
  14 #include "swab.h"
  15 #include "util.h"
  16
  17 struct ufs_buffer_head * _ubh_bread_ (struct ufs_sb_private_info * uspi,
  18         struct super_block *sb, u64 fragment, u64 size)
  19 {
  20         struct ufs_buffer_head * ubh;
  21         unsigned i, j ;
  22         u64  count = 0;
  23         if (size & ~uspi->s_fmask)
  24                 return NULL;
  25         count = size >> uspi->s_fshift;
  26         if (count > UFS_MAXFRAG)
  27                 return NULL;
  28         ubh = (struct ufs_buffer_head *)
  29                 kmalloc (sizeof (struct ufs_buffer_head), GFP_KERNEL);
  30         if (!ubh)
  31                 return NULL;
  32         ubh->fragment = fragment;
  33         ubh->count = count;
  34         for (i = 0; i < count; i++)
  35                 if (!(ubh->bh[i] = sb_bread(sb, fragment + i)))
  36                         goto failed;
  37         for (; i < UFS_MAXFRAG; i++)
  38                 ubh->bh[i] = NULL;
  39         return ubh;
  40 failed:
  41         for (j = 0; j < i; j++)
  42                 brelse (ubh->bh[j]);
  43         kfree(ubh);
  44         return NULL;
  45 }
  46
  47 struct ufs_buffer_head * ubh_bread_uspi (struct ufs_sb_private_info * uspi,
  48         struct super_block *sb, u64 fragment, u64 size)
  49 {
  50         unsigned i, j;
  51         u64 count = 0;
  52         if (size & ~uspi->s_fmask)
  53                 return NULL;
  54         count = size >> uspi->s_fshift;
  55         if (count <= 0 || count > UFS_MAXFRAG)
  56                 return NULL;
  57         USPI_UBH(uspi)->fragment = fragment;
  58         USPI_UBH(uspi)->count = count;
  59         for (i = 0; i < count; i++)
  60                 if (!(USPI_UBH(uspi)->bh[i] = sb_bread(sb, fragment + i)))
  61                         goto failed;
  62         for (; i < UFS_MAXFRAG; i++)
  63                 USPI_UBH(uspi)->bh[i] = NULL;
  64         return USPI_UBH(uspi);
  65 failed:
  66         for (j = 0; j < i; j++)
  67                 brelse (USPI_UBH(uspi)->bh[j]);
  68         return NULL;
  69 }
  70
  71 void ubh_brelse (struct ufs_buffer_head * ubh)
  72 {
  73         unsigned i;
  74         if (!ubh)
  75                 return;
  76         for (i = 0; i < ubh->count; i++)
  77                 brelse (ubh->bh[i]);
  78         kfree (ubh);
  79 }
  80
  81 void ubh_brelse_uspi (struct ufs_sb_private_info * uspi)
  82 {
  83         unsigned i;
  84         if (!USPI_UBH(uspi))
  85                 return;
  86         for ( i = 0; i < USPI_UBH(uspi)->count; i++ ) {
  87                 brelse (USPI_UBH(uspi)->bh[i]);
  88                 USPI_UBH(uspi)->bh[i] = NULL;
  89         }
  90 }
  91
  92 void ubh_mark_buffer_dirty (struct ufs_buffer_head * ubh)
  93 {
  94         unsigned i;
  95         if (!ubh)
  96                 return;
  97         for ( i = 0; i < ubh->count; i++ )
  98                 mark_buffer_dirty (ubh->bh[i]);
  99 }
 100
 101 void ubh_mark_buffer_uptodate (struct ufs_buffer_head * ubh, int flag)
 102 {
 103         unsigned i;
 104         if (!ubh)
 105                 return;
 106         if (flag) {
 107                 for ( i = 0; i < ubh->count; i++ )
 108                         set_buffer_uptodate (ubh->bh[i]);
 109         } else {
 110                 for ( i = 0; i < ubh->count; i++ )
 111                         clear_buffer_uptodate (ubh->bh[i]);
 112         }
 113 }
 114
 115 void ubh_ll_rw_block(int rw, struct ufs_buffer_head *ubh)
 116 {
 117         if (!ubh)
 118                 return;
 119
 120         ll_rw_block(rw, ubh->count, ubh->bh);
 121 }
 122
 123 void ubh_wait_on_buffer (struct ufs_buffer_head * ubh)
 124 {
 125         unsigned i;
 126         if (!ubh)
 127                 return;
 128         for ( i = 0; i < ubh->count; i++ )
 129                 wait_on_buffer (ubh->bh[i]);
 130 }
 131
 132 void ubh_bforget (struct ufs_buffer_head * ubh)
 133 {
 134         unsigned i;
 135         if (!ubh)
 136                 return;
 137         for ( i = 0; i < ubh->count; i++ ) if ( ubh->bh[i] )
 138                 bforget (ubh->bh[i]);
 139 }
 140
 141 int ubh_buffer_dirty (struct ufs_buffer_head * ubh)
 142 {
 143         unsigned i;
 144         unsigned result = 0;
 145         if (!ubh)
 146                 return 0;
 147         for ( i = 0; i < ubh->count; i++ )
 148                 result |= buffer_dirty(ubh->bh[i]);
 149         return result;
 150 }
 151
 152 void _ubh_ubhcpymem_(struct ufs_sb_private_info * uspi,
 153         unsigned char * mem, struct ufs_buffer_head * ubh, unsigned size)
 154 {
 155         unsigned len, bhno;
 156         if (size > (ubh->count << uspi->s_fshift))
 157                 size = ubh->count << uspi->s_fshift;
 158         bhno = 0;
 159         while (size) {
 160                 len = min_t(unsigned int, size, uspi->s_fsize);
 161                 memcpy (mem, ubh->bh[bhno]->b_data, len);
 162                 mem += uspi->s_fsize;
 163                 size -= len;
 164                 bhno++;
 165         }
 166 }
 167
 168 void _ubh_memcpyubh_(struct ufs_sb_private_info * uspi,
 169         struct ufs_buffer_head * ubh, unsigned char * mem, unsigned size)
 170 {
 171         unsigned len, bhno;
 172         if (size > (ubh->count << uspi->s_fshift))
 173                 size = ubh->count << uspi->s_fshift;
 174         bhno = 0;
 175         while (size) {
 176                 len = min_t(unsigned int, size, uspi->s_fsize);
 177                 memcpy (ubh->bh[bhno]->b_data, mem, len);
 178                 mem += uspi->s_fsize;
 179                 size -= len;
 180                 bhno++;
 181         }
 182 }
 183
 184 dev_t
 185 ufs_get_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi)
 186 {
 187         __u32 fs32;
 188         dev_t dev;
 189
 190         if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
 191                 fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[1]);
 192         else
 193                 fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[0]);
 194         switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
 195         case UFS_ST_SUNx86:
 196         case UFS_ST_SUN:
 197                 if ((fs32 & 0xffff0000) == 0 ||
 198                     (fs32 & 0xffff0000) == 0xffff0000)
 199                         dev = old_decode_dev(fs32 & 0x7fff);
 200                 else
 201                         dev = MKDEV(sysv_major(fs32), sysv_minor(fs32));
 202                 break;
 203
 204         default:
 205                 dev = old_decode_dev(fs32);
 206                 break;
 207         }
 208         return dev;
 209 }
 210
 211 void
 212 ufs_set_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi, dev_t dev)
 213 {
 214         __u32 fs32;
 215
 216         switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
 217         case UFS_ST_SUNx86:
 218         case UFS_ST_SUN:
 219                 fs32 = sysv_encode_dev(dev);
 220                 if ((fs32 & 0xffff8000) == 0) {
 221                         fs32 = old_encode_dev(dev);
 222                 }
 223                 break;
 224
 225         default:
 226                 fs32 = old_encode_dev(dev);
 227                 break;
 228         }
 229         if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
 230                 ufsi->i_u1.i_data[1] = cpu_to_fs32(sb, fs32);
 231         else
 232                 ufsi->i_u1.i_data[0] = cpu_to_fs32(sb, fs32);
 233 }
 234
 235 /**
 236  * ufs_get_locked_page() - locate, pin and lock a pagecache page, if not exist
 237  * read it from disk.
 238  * @mapping: the address_space to search
 239  * @index: the page index
 240  *
 241  * Locates the desired pagecache page, if not exist we'll read it,
 242  * locks it, increments its reference
 243  * count and returns its address.
 244  *
 245  */
 246
 247 struct page *ufs_get_locked_page(struct address_space *mapping,
 248                                  pgoff_t index)
 249 {
 250         struct page *page;
 251
 252         page = find_lock_page(mapping, index);
 253         if (!page) {
 254                 page = read_cache_page(mapping, index,
 255                                        (filler_t*)mapping->a_ops->readpage,
 256                                        NULL);
 257
 258                 if (IS_ERR(page)) {
 259                         printk(KERN_ERR "ufs_change_blocknr: "
 260                                "read_cache_page error: ino %lu, index: %lu\n",
 261                                mapping->host->i_ino, index);
 262                         goto out;
 263                 }
 264
 265                 lock_page(page);
 266
 267                 if (unlikely(page->mapping == NULL)) {
 268                         /* Truncate got there first */
 269                         unlock_page(page);
 270                         page_cache_release(page);
 271                         page = NULL;
 272                         goto out;
 273                 }
 274
 275                 if (!PageUptodate(page) || PageError(page)) {
 276                         unlock_page(page);
 277                         page_cache_release(page);
 278
 279                         printk(KERN_ERR "ufs_change_blocknr: "
 280                                "can not read page: ino %lu, index: %lu\n",
 281                                mapping->host->i_ino, index);
 282
 283                         page = ERR_PTR(-EIO);
 284                 }
 285         }
 286 out:
 287         return page;
 288 }