getsize.c revision 3efc3a04fc77bf53d5d1ad433144b82b441e0806 
1/*
2 * getsize.c --- get the size of a partition.
3 *
4 * Copyright (C) 1995, 1995 Theodore Ts'o.
5 * Copyright (C) 2003 VMware, Inc.
6 *
7 * Windows version of ext2fs_get_device_size by Chris Li, VMware.
8 *
9 * %Begin-Header%
10 * This file may be redistributed under the terms of the GNU Public
11 * License.
12 * %End-Header%
13 */
14
15#define _LARGEFILE_SOURCE
16#define _LARGEFILE64_SOURCE
17
18#include <stdio.h>
19#if HAVE_UNISTD_H
20#include <unistd.h>
21#endif
22#if HAVE_ERRNO_H
23#include <errno.h>
24#endif
25#include <fcntl.h>
26#ifdef HAVE_SYS_IOCTL_H
27#include <sys/ioctl.h>
28#endif
29#ifdef HAVE_LINUX_FD_H
30#include <linux/fd.h>
31#endif
32#ifdef HAVE_SYS_DISKLABEL_H
33#include <sys/disklabel.h>
34#endif
35#ifdef HAVE_SYS_DISK_H
36#ifdef HAVE_SYS_QUEUE_H
37#include <sys/queue.h> /* for LIST_HEAD */
38#endif
39#include <sys/disk.h>
40#endif
41#ifdef __linux__
42#include <sys/utsname.h>
43#endif
44#if HAVE_SYS_STAT_H
45#include <sys/stat.h>
46#endif
47#include <ctype.h>
48
49#if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE)
50#define BLKGETSIZE _IO(0x12,96)	/* return device size */
51#endif
52
53#if defined(__linux__) && defined(_IOR) && !defined(BLKGETSIZE64)
54#define BLKGETSIZE64 _IOR(0x12,114,size_t)	/* return device size in bytes (u64 *arg) */
55#endif
56
57#ifdef APPLE_DARWIN
58#define BLKGETSIZE DKIOCGETBLOCKCOUNT32
59#endif /* APPLE_DARWIN */
60
61#include "ext2_fs.h"
62#include "ext2fs.h"
63
64#if defined(__CYGWIN__) || defined (WIN32)
65#include "windows.h"
66#include "winioctl.h"
67
68#if (_WIN32_WINNT >= 0x0500)
69#define HAVE_GET_FILE_SIZE_EX 1
70#endif
71
72errcode_t ext2fs_get_device_size(const char *file, int blocksize,
73				 blk_t *retblocks)
74{
75	HANDLE dev;
76	PARTITION_INFORMATION pi;
77	DISK_GEOMETRY gi;
78	DWORD retbytes;
79#ifdef HAVE_GET_FILE_SIZE_EX
80	LARGE_INTEGER filesize;
81#else
82	DWORD filesize;
83#endif /* HAVE_GET_FILE_SIZE_EX */
84
85	dev = CreateFile(file, GENERIC_READ,
86			 FILE_SHARE_READ | FILE_SHARE_WRITE ,
87                	 NULL,  OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,  NULL);
88
89	if (dev == INVALID_HANDLE_VALUE)
90		return EBADF;
91	if (DeviceIoControl(dev, IOCTL_DISK_GET_PARTITION_INFO,
92			    &pi, sizeof(PARTITION_INFORMATION),
93			    &pi, sizeof(PARTITION_INFORMATION),
94			    &retbytes, NULL)) {
95
96		*retblocks = pi.PartitionLength.QuadPart / blocksize;
97
98	} else if (DeviceIoControl(dev, IOCTL_DISK_GET_DRIVE_GEOMETRY,
99				&gi, sizeof(DISK_GEOMETRY),
100				&gi, sizeof(DISK_GEOMETRY),
101				&retbytes, NULL)) {
102
103		*retblocks = gi.BytesPerSector *
104			     gi.SectorsPerTrack *
105			     gi.TracksPerCylinder *
106			     gi.Cylinders.QuadPart / blocksize;
107
108#ifdef HAVE_GET_FILE_SIZE_EX
109	} else if (GetFileSizeEx(dev, &filesize)) {
110		*retblocks = filesize.QuadPart / blocksize;
111	}
112#else
113	} else {
114		filesize = GetFileSize(dev, NULL);
115		if (INVALID_FILE_SIZE != filesize) {
116			*retblocks = filesize / blocksize;
117		}
118	}
119#endif /* HAVE_GET_FILE_SIZE_EX */
120
121	CloseHandle(dev);
122	return 0;
123}
124
125#else
126
127static int valid_offset (int fd, ext2_loff_t offset)
128{
129	char ch;
130
131	if (ext2fs_llseek (fd, offset, 0) < 0)
132		return 0;
133	if (read (fd, &ch, 1) < 1)
134		return 0;
135	return 1;
136}
137
138/*
139 * Returns the number of blocks in a partition
140 */
141errcode_t ext2fs_get_device_size(const char *file, int blocksize,
142				 blk_t *retblocks)
143{
144	int	fd, rc = 0;
145	int valid_blkgetsize64 = 1;
146#ifdef __linux__
147	struct 		utsname ut;
148#endif
149	unsigned long long size64;
150	unsigned long	size;
151	ext2_loff_t high, low;
152#ifdef FDGETPRM
153	struct floppy_struct this_floppy;
154#endif
155#ifdef HAVE_SYS_DISKLABEL_H
156	int part;
157	struct disklabel lab;
158	struct partition *pp;
159	char ch;
160#endif /* HAVE_SYS_DISKLABEL_H */
161
162#ifdef HAVE_OPEN64
163	fd = open64(file, O_RDONLY);
164#else
165	fd = open(file, O_RDONLY);
166#endif
167	if (fd < 0)
168		return errno;
169
170#ifdef DKIOCGETBLOCKCOUNT	/* For Apple Darwin */
171	if (ioctl(fd, DKIOCGETBLOCKCOUNT, &size64) >= 0) {
172		if ((sizeof(*retblocks) < sizeof(unsigned long long))
173		    && ((size64 / (blocksize / 512)) > 0xFFFFFFFF))
174			return EFBIG;
175		*retblocks = size64 / (blocksize / 512);
176		goto out;
177	}
178#endif
179
180#ifdef BLKGETSIZE64
181#ifdef __linux__
182	if ((uname(&ut) == 0) &&
183	    ((ut.release[0] == '2') && (ut.release[1] == '.') &&
184	     (ut.release[2] < '6') && (ut.release[3] == '.')))
185		valid_blkgetsize64 = 0;
186#endif
187	if (valid_blkgetsize64 &&
188	    ioctl(fd, BLKGETSIZE64, &size64) >= 0) {
189		if ((sizeof(*retblocks) < sizeof(unsigned long long)) &&
190		    ((size64 / blocksize) > 0xFFFFFFFF)) {
191			rc = EFBIG;
192			goto out;
193		}
194		*retblocks = size64 / blocksize;
195		goto out;
196	}
197#endif
198
199#ifdef BLKGETSIZE
200	if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
201		*retblocks = size / (blocksize / 512);
202		goto out;
203	}
204#endif
205
206#ifdef FDGETPRM
207	if (ioctl(fd, FDGETPRM, &this_floppy) >= 0) {
208		*retblocks = this_floppy.size / (blocksize / 512);
209		goto out;
210	}
211#endif
212
213#ifdef HAVE_SYS_DISKLABEL_H
214#if defined(DIOCGMEDIASIZE)
215	{
216	    off_t ms;
217	    u_int bs;
218	    if (ioctl(fd, DIOCGMEDIASIZE, &ms) >= 0) {
219		*retblocks = ms / blocksize;
220		goto out;
221	    }
222	}
223#elif defined(DIOCGDINFO)
224	/* old disklabel interface */
225	part = strlen(file) - 1;
226	if (part >= 0) {
227		ch = file[part];
228		if (isdigit(ch))
229			part = 0;
230		else if (ch >= 'a' && ch <= 'h')
231			part = ch - 'a';
232		else
233			part = -1;
234	}
235	if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) {
236		pp = &lab.d_partitions[part];
237		if (pp->p_size) {
238			*retblocks = pp->p_size / (blocksize / 512);
239			goto out;
240		}
241	}
242#endif /* defined(DIOCG*) */
243#endif /* HAVE_SYS_DISKLABEL_H */
244
245	{
246#ifdef HAVE_FSTAT64
247		struct stat64   st;
248		if (fstat64(fd, &st) == 0)
249#else
250		struct stat	st;
251		if (fstat(fd, &st) == 0)
252#endif
253			if (S_ISREG(st.st_mode)) {
254				if ((sizeof(*retblocks) < sizeof(unsigned long long)) &&
255				    ((st.st_size / blocksize) > 0xFFFFFFFF)) {
256					rc = EFBIG;
257					goto out;
258				}
259				*retblocks = st.st_size / blocksize;
260				goto out;
261			}
262	}
263
264	/*
265	 * OK, we couldn't figure it out by using a specialized ioctl,
266	 * which is generally the best way.  So do binary search to
267	 * find the size of the partition.
268	 */
269	low = 0;
270	for (high = 1024; valid_offset (fd, high); high *= 2)
271		low = high;
272	while (low < high - 1)
273	{
274		const ext2_loff_t mid = (low + high) / 2;
275
276		if (valid_offset (fd, mid))
277			low = mid;
278		else
279			high = mid;
280	}
281	valid_offset (fd, 0);
282	size64 = low + 1;
283	if ((sizeof(*retblocks) < sizeof(unsigned long long))
284	    && ((size64 / blocksize) > 0xFFFFFFFF))
285		return EFBIG;
286	*retblocks = size64 / blocksize;
287out:
288	close(fd);
289	return rc;
290}
291
292#endif /* WIN32 */
293
294#ifdef DEBUG
295int main(int argc, char **argv)
296{
297	blk_t	blocks;
298	int	retval;
299
300	if (argc < 2) {
301		fprintf(stderr, "Usage: %s device\n", argv[0]);
302		exit(1);
303	}
304
305	retval = ext2fs_get_device_size(argv[1], 1024, &blocks);
306	if (retval) {
307		com_err(argv[0], retval,
308			"while calling ext2fs_get_device_size");
309		exit(1);
310	}
311	printf("Device %s has %u 1k blocks.\n", argv[1], blocks);
312	exit(0);
313}
314#endif
315