2 * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #define _FILE_OFFSET_BITS 64
31 #include <ext4_config.h>
32 #include <ext4_blockdev.h>
33 #include <ext4_errno.h>
39 /**@brief Default filename.*/
40 static const char *fname = "ext2";
42 /**@brief Image block size.*/
43 #define EXT4_FILEDEV_BSIZE 512
45 /**@brief Image file descriptor.*/
46 static FILE *dev_file;
48 #define DROP_LINUXCACHE_BUFFERS 0
50 /**********************BLOCKDEV INTERFACE**************************************/
51 static int filedev_open(struct ext4_blockdev *bdev);
52 static int filedev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
54 static int filedev_bwrite(struct ext4_blockdev *bdev, const void *buf,
55 uint64_t blk_id, uint32_t blk_cnt);
56 static int filedev_close(struct ext4_blockdev *bdev);
58 /******************************************************************************/
59 EXT4_BLOCKDEV_STATIC_INSTANCE(_filedev, EXT4_FILEDEV_BSIZE, 0, filedev_open,
60 filedev_bread, filedev_bwrite, filedev_close);
62 /******************************************************************************/
63 static int filedev_open(struct ext4_blockdev *bdev)
65 dev_file = fopen(fname, "r+b");
70 /*No buffering at file.*/
73 if (fseek(dev_file, 0, SEEK_END))
76 _filedev.ph_bcnt = ftell(dev_file) / _filedev.ph_bsize;
81 /******************************************************************************/
83 static int filedev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
86 if (fseek(dev_file, blk_id * bdev->ph_bsize, SEEK_SET))
89 if (!fread(buf, bdev->ph_bsize * blk_cnt, 1, dev_file))
95 static void drop_cache(void)
97 #if defined(__linux__) && DROP_LINUXCACHE_BUFFERS
102 fd = open("/proc/sys/vm/drop_caches", O_WRONLY);
103 write(fd, data, sizeof(char));
108 /******************************************************************************/
109 static int filedev_bwrite(struct ext4_blockdev *bdev, const void *buf,
110 uint64_t blk_id, uint32_t blk_cnt)
112 if (fseek(dev_file, blk_id * bdev->ph_bsize, SEEK_SET))
115 if (!fwrite(buf, bdev->ph_bsize * blk_cnt, 1, dev_file))
121 /******************************************************************************/
122 static int filedev_close(struct ext4_blockdev *bdev)
128 /******************************************************************************/
129 struct ext4_blockdev *ext4_filedev_get(void) { return &_filedev; }
130 /******************************************************************************/
131 void ext4_filedev_filename(const char *n) { fname = n; }
133 /******************************************************************************/