lib: add blkdev.{c,h}

Now we duplicate BLK* ioctls on many places... This patch also
fix BLKGETSIZE64 usage in dependence on kernel version.

Co-Author: Karel Zak <kzak@redhat.com>
Signed-off-by: Stefan Krah <stefan@bytereef.org>
Signed-off-by: Karel Zak <kzak@redhat.com>

4 files changed, 154 insertions, 2 deletions

diff --git a/include/Makefile.am b/include/Makefile.am
index 275661dee..e2b99d6c0 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -2,4 +2,4 @@ include $(top_srcdir)/config/include-Makefile.am
 
 dist_noinst_HEADERS = carefulputc.h env.h linux_reboot.h md5.h \
 	nls.h pathnames.h setproctitle.h widechar.h xstrncpy.h \
-	linux_version.h
+	linux_version.h blkdev.h
diff --git a/include/blkdev.h b/include/blkdev.h
new file mode 100644
index 000000000..8065acc1e
--- /dev/null
+++ b/include/blkdev.h
@@ -0,0 +1,55 @@
+#ifndef BLKDEV_H
+#define BLKDEV_H
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+
+#define DEFAULT_SECTOR_SIZE       512
+
+#ifndef BLKROSET
+
+#define BLKROSET   _IO(0x12,93)	/* set device read-only (0 = read-write) */
+#define BLKROGET   _IO(0x12,94)	/* get read-only status (0 = read_write) */
+#define BLKRRPART  _IO(0x12,95)	/* re-read partition table */
+#define BLKGETSIZE _IO(0x12,96)	/* return device size /512 (long *arg) */
+#define BLKFLSBUF  _IO(0x12,97)	/* flush buffer cache */
+#define BLKRASET   _IO(0x12,98)	/* set read ahead for block device */
+#define BLKRAGET   _IO(0x12,99)	/* get current read ahead setting */
+#define BLKFRASET  _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
+#define BLKFRAGET  _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
+#define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
+#define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
+#define BLKSSZGET  _IO(0x12,104)/* get block device sector size */
+
+#define BLKELVGET  _IOR(0x12,106,size_t) /* elevator get */
+#define BLKELVSET  _IOW(0x12,107,size_t) /* elevator set */
+
+#define BLKGETLASTSECT _IO(0x12,108) /* get last sector of block device */
+
+#define BLKBSZGET  _IOR(0x12,112,size_t)
+#define BLKBSZSET  _IOW(0x12,113,size_t)
+#define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
+
+#endif /* BLKROSET */
+
+#ifndef HDIO_GETGEO
+#define HDIO_GETGEO 0x0301
+struct hd_geometry {
+	unsigned char heads;
+	unsigned char sectors;
+	unsigned short cylinders;	/* truncated */
+	unsigned long start;
+};
+#endif
+
+/* get size in bytes */
+int blkdev_get_size(int fd, unsigned long long *bytes);
+
+/* get 512-byte sector count */
+int blkdev_get_sectors(int fd, unsigned long long *sectors);
+
+/* get hardware sector size */
+int blkdev_get_sector_size(int fd, int *sector_size);
+
+
+#endif /* BLKDEV_H */
diff --git a/lib/blkdev.c b/lib/blkdev.c
new file mode 100644
index 000000000..29c5d0bd4
--- /dev/null
+++ b/lib/blkdev.c
@@ -0,0 +1,93 @@
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+
+#include "blkdev.h"
+#include "linux_version.h"
+
+/* get size in bytes */
+int
+blkdev_get_size(int fd, unsigned long long *bytes)
+{
+	unsigned long size;
+	int ver = get_linux_version();
+
+	/* kernels 2.4.15-2.4.17, had a broken BLKGETSIZE64 */
+	if (ver >= KERNEL_VERSION (2,6,0) ||
+	   (ver >= KERNEL_VERSION (2,4,18) && ver < KERNEL_VERSION (2,5,0))) {
+
+		if (ioctl(fd, BLKGETSIZE64, bytes) >= 0)
+			return 0;
+	}
+	if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
+		*bytes = ((unsigned long long)size << 9);
+		return 0;
+	}
+
+	return -1;
+}
+
+/* get 512-byte sector count */
+int
+blkdev_get_sectors(int fd, unsigned long long *sectors)
+{
+	unsigned long long bytes;
+
+	if (blkdev_get_size(fd, &bytes) == 0) {
+		*sectors = (bytes >> 9);
+		return 0;
+	}
+
+	return -1;
+}
+
+/* get hardware sector size */
+int
+blkdev_get_sector_size(int fd, int *sector_size)
+{
+	if (get_linux_version() < KERNEL_VERSION(2,3,3)) {
+		*sector_size = DEFAULT_SECTOR_SIZE;
+		return 0;
+	}
+	if (ioctl(fd, BLKSSZGET, sector_size) >= 0)
+		return 0;
+
+	return -1;
+}
+
+
+#ifdef MAIN_TEST_BLKDEV
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <err.h>
+int
+main(int argc, char **argv)
+{
+	unsigned long long bytes;
+	unsigned long long sectors;
+	int sector_size;
+	int fd;
+
+	if (argc != 2) {
+		fprintf(stderr, "usage: %s device\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	if ((fd = open(argv[1], O_RDONLY)) < 0)
+		err(EXIT_FAILURE, "open %s failed", argv[1]);
+
+	if (blkdev_get_size(fd, &bytes) < 0)
+		err(EXIT_FAILURE, "blkdev_get_size() failed");
+	if (blkdev_get_sectors(fd, &sectors) < 0)
+		err(EXIT_FAILURE, "blkdev_get_sectors() failed");
+	if (blkdev_get_sector_size(fd, &sector_size) < 0)
+		err(EXIT_FAILURE, "blkdev_get_sector_size() failed");
+
+	printf("bytes %llu\n", bytes);
+	printf("sectors %llu\n", sectors);
+	printf("sectorsize %d\n", sector_size);
+
+	return EXIT_SUCCESS;
+}
+#endif /* TEST_PROGRAM */
diff --git a/tests/helpers/Makefile.am b/tests/helpers/Makefile.am
index b6f0557f4..0f28a7f8a 100644
--- a/tests/helpers/Makefile.am
+++ b/tests/helpers/Makefile.am
@@ -1,5 +1,9 @@
 include $(top_srcdir)/config/include-Makefile.am
 
-noinst_PROGRAMS = mnt_test_sysinfo
+noinst_PROGRAMS = mnt_test_sysinfo test_blkdev
 mnt_test_sysinfo_SOURCES = mnt_test_sysinfo.c
 
+test_blkdev_SOURCES = 	$(top_srcdir)/lib/blkdev.c \
+			$(top_srcdir)/lib/linux_version.c
+test_blkdev_CFLAGS = -DMAIN_TEST_BLKDEV
+