lib/ext2fs/io_manager.c

   1 /*
   2  * io_manager.c --- the I/O manager abstraction
   3  */
   4
   5 #include "config.h"
   6 #include <stdio.h>
   7 #include <string.h>
   8 #if HAVE_UNISTD_H
   9 #include <unistd.h>
  10 #endif
  11 #include <fcntl.h>
  12 #include <time.h>
  13 #if HAVE_SYS_STAT_H
  14 #include <sys/stat.h>
  15 #endif
  16 #if HAVE_SYS_TYPES_H
  17 #include <sys/types.h>
  18 #endif
  19
  20 #include "ext2_fs.h"
  21 #include "ext2fs.h"
  22
  23 errcode_t io_channel_set_options(io_channel channel, const char *opts)
  24 {
  25         errcode_t retval = 0;
  26         char *next, *ptr, *options, *arg;
  27
  28         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
  29
  30         if (!opts)
  31                 return 0;
  32
  33         if (!channel->manager->set_option)
  34                 return EXT2_ET_INVALID_ARGUMENT;
  35
  36         options = malloc(strlen(opts)+1);
  37         if (!options)
  38                 return EXT2_ET_NO_MEMORY;
  39         strcpy(options, opts);
  40         ptr = options;
  41
  42         while (ptr && *ptr) {
  43                 next = strchr(ptr, '&');
  44                 if (next)
  45                         *next++ = 0;
  46
  47                 arg = strchr(ptr, '=');
  48                 if (arg)
  49                         *arg++ = 0;
  50
  51                 retval = (channel->manager->set_option)(channel, ptr, arg);
  52                 if (retval)
  53                         break;
  54                 ptr = next;
  55         }
  56         free(options);
  57         return retval;
  58 }
  59
  60 errcode_t io_channel_write_byte(io_channel channel, unsigned long offset,
  61                                 int count, const void *data)
  62 {
  63         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
  64
  65         if (channel->manager->write_byte)
  66                 return channel->manager->write_byte(channel, offset,
  67                                                     count, data);
  68
  69         return EXT2_ET_UNIMPLEMENTED;
  70 }
  71
  72 errcode_t io_channel_read_blk64(io_channel channel, unsigned long long block,
  73                                  int count, void *data)
  74 {
  75         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
  76
  77         if (channel->manager->read_blk64)
  78                 return (channel->manager->read_blk64)(channel, block,
  79                                                       count, data);
  80
  81         if ((block >> 32) != 0)
  82                 return EXT2_ET_IO_CHANNEL_NO_SUPPORT_64;
  83
  84         return (channel->manager->read_blk)(channel, (unsigned long) block,
  85                                              count, data);
  86 }
  87
  88 errcode_t io_channel_write_blk64(io_channel channel, unsigned long long block,
  89                                  int count, const void *data)
  90 {
  91         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
  92
  93         if (channel->manager->write_blk64)
  94                 return (channel->manager->write_blk64)(channel, block,
  95                                                        count, data);
  96
  97         if ((block >> 32) != 0)
  98                 return EXT2_ET_IO_CHANNEL_NO_SUPPORT_64;
  99
 100         return (channel->manager->write_blk)(channel, (unsigned long) block,
 101                                              count, data);
 102 }
 103
 104 errcode_t io_channel_discard(io_channel channel, unsigned long long block,
 105                              unsigned long long count)
 106 {
 107         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 108
 109         if (channel->manager->discard)
 110                 return (channel->manager->discard)(channel, block, count);
 111
 112         return EXT2_ET_UNIMPLEMENTED;
 113 }
 114
 115 errcode_t io_channel_zeroout(io_channel channel, unsigned long long block,
 116                              unsigned long long count)
 117 {
 118         EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 119
 120         if (channel->manager->zeroout)
 121                 return (channel->manager->zeroout)(channel, block, count);
 122
 123         return EXT2_ET_UNIMPLEMENTED;
 124 }
 125
 126 errcode_t io_channel_alloc_buf(io_channel io, int count, void *ptr)
 127 {
 128         size_t  size;
 129
 130         if (count == 0)
 131                 size = io->block_size;
 132         else if (count > 0)
 133                 size = io->block_size * count;
 134         else
 135                 size = -count;
 136
 137         if (io->align)
 138                 return ext2fs_get_memalign(size, io->align, ptr);
 139         else
 140                 return ext2fs_get_mem(size, ptr);
 141 }
 142
 143 errcode_t io_channel_cache_readahead(io_channel io, unsigned long long block,
 144                                      unsigned long long count)
 145 {
 146         if (!io->manager->cache_readahead)
 147                 return EXT2_ET_OP_NOT_SUPPORTED;
 148
 149         return io->manager->cache_readahead(io, block, count);
 150 }