1 files changed, 452 insertions, 0 deletions
diff --git a/lib/blkdev.c b/lib/blkdev.c
new file mode 100644
index 0000000..c22853d
--- /dev/null
+++ b/lib/blkdev.c
@@ -0,0 +1,452 @@
+/*
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
+ *
+ * Written by Karel Zak <kzak@redhat.com>
+ */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <stdint.h>
+
+#ifdef HAVE_LINUX_FD_H
+#include <linux/fd.h>
+#endif
+
+#ifdef HAVE_SYS_DISKLABEL_H
+#include <sys/disklabel.h>
+#endif
+
+#ifdef HAVE_SYS_DISK_H
+# include <sys/disk.h>
+#endif
+
+#ifndef EBADFD
+# define EBADFD 77		/* File descriptor in bad state */
+#endif
+
+#include "blkdev.h"
+#include "c.h"
+#include "linux_version.h"
+#include "fileutils.h"
+#include "nls.h"
+
+static long
+blkdev_valid_offset (int fd, off_t offset) {
+	char ch;
+
+	if (lseek (fd, offset, 0) < 0)
+		return 0;
+	if (read (fd, &ch, 1) < 1)
+		return 0;
+	return 1;
+}
+
+int is_blkdev(int fd)
+{
+	struct stat st;
+	return (fstat(fd, &st) == 0 && S_ISBLK(st.st_mode));
+}
+
+off_t
+blkdev_find_size (int fd) {
+	uintmax_t high, low = 0;
+
+	for (high = 1024; blkdev_valid_offset (fd, high); ) {
+		if (high == UINTMAX_MAX)
+			return -1;
+
+		low = high;
+
+		if (high >= UINTMAX_MAX/2)
+			high = UINTMAX_MAX;
+		else
+			high *= 2;
+	}
+
+	while (low < high - 1)
+	{
+		uintmax_t mid = (low + high) / 2;
+
+		if (blkdev_valid_offset (fd, mid))
+			low = mid;
+		else
+			high = mid;
+	}
+	blkdev_valid_offset (fd, 0);
+	return (low + 1);
+}
+
+/* get size in bytes */
+int
+blkdev_get_size(int fd, unsigned long long *bytes)
+{
+#ifdef DKIOCGETBLOCKCOUNT
+	/* Apple Darwin */
+	if (ioctl(fd, DKIOCGETBLOCKCOUNT, bytes) >= 0) {
+		*bytes <<= 9;
+		return 0;
+	}
+#endif
+
+#ifdef BLKGETSIZE64
+	if (ioctl(fd, BLKGETSIZE64, bytes) >= 0)
+		return 0;
+#endif
+
+#ifdef BLKGETSIZE
+	{
+		unsigned long size;
+
+		if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
+			*bytes = ((unsigned long long)size << 9);
+			return 0;
+		}
+	}
+
+#endif /* BLKGETSIZE */
+
+#ifdef DIOCGMEDIASIZE
+	/* FreeBSD */
+	if (ioctl(fd, DIOCGMEDIASIZE, bytes) >= 0)
+		return 0;
+#endif
+
+#ifdef FDGETPRM
+	{
+		struct floppy_struct this_floppy;
+
+		if (ioctl(fd, FDGETPRM, &this_floppy) >= 0) {
+			*bytes = ((unsigned long long) this_floppy.size) << 9;
+			return 0;
+		}
+	}
+#endif /* FDGETPRM */
+
+#if defined(HAVE_SYS_DISKLABEL_H) && defined(DIOCGDINFO)
+	{
+		/*
+		 * This code works for FreeBSD 4.11 i386, except for the full device
+		 * (such as /dev/ad0). It doesn't work properly for newer FreeBSD
+		 * though. FreeBSD >= 5.0 should be covered by the DIOCGMEDIASIZE
+		 * above however.
+		 *
+		 * Note that FreeBSD >= 4.0 has disk devices as unbuffered (raw,
+		 * character) devices, so we need to check for S_ISCHR, too.
+		 */
+		int part = -1;
+		struct disklabel lab;
+		struct partition *pp;
+		struct stat st;
+
+		if ((fstat(fd, &st) >= 0) &&
+		    (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode)))
+			part = st.st_rdev & 7;
+
+		if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) {
+			pp = &lab.d_partitions[part];
+			if (pp->p_size) {
+				 *bytes = pp->p_size << 9;
+				 return 0;
+			}
+		}
+	}
+#endif /* defined(HAVE_SYS_DISKLABEL_H) && defined(DIOCGDINFO) */
+
+	{
+		struct stat st;
+
+		if (fstat(fd, &st) == 0 && S_ISREG(st.st_mode)) {
+			*bytes = st.st_size;
+			return 0;
+		}
+		if (!S_ISBLK(st.st_mode))
+			return -1;
+	}
+
+	*bytes = blkdev_find_size(fd);
+	return 0;
+}
+
+/* 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 logical sector size.
+ *
+ * This is the smallest unit the storage device can
+ * address. It is typically 512 bytes.
+ */
+#ifdef BLKSSZGET
+int blkdev_get_sector_size(int fd, int *sector_size)
+{
+	if (ioctl(fd, BLKSSZGET, sector_size) >= 0)
+		return 0;
+	return -1;
+}
+#else
+int blkdev_get_sector_size(int fd __attribute__((__unused__)), int *sector_size)
+{
+	*sector_size = DEFAULT_SECTOR_SIZE;
+	return 0;
+}
+#endif
+
+/*
+ * Get physical block device size. The BLKPBSZGET is supported since Linux
+ * 2.6.32. For old kernels is probably the best to assume that physical sector
+ * size is the same as logical sector size.
+ *
+ * Example:
+ *
+ * rc = blkdev_get_physector_size(fd, &physec);
+ * if (rc || physec == 0) {
+ *	rc = blkdev_get_sector_size(fd, &physec);
+ *	if (rc)
+ *		physec = DEFAULT_SECTOR_SIZE;
+ * }
+ */
+#ifdef BLKPBSZGET
+int blkdev_get_physector_size(int fd, int *sector_size)
+{
+	if (ioctl(fd, BLKPBSZGET, &sector_size) >= 0)
+		return 0;
+	return -1;
+}
+#else
+int blkdev_get_physector_size(int fd __attribute__((__unused__)), int *sector_size)
+{
+	*sector_size = DEFAULT_SECTOR_SIZE;
+	return 0;
+}
+#endif
+
+/*
+ * Return the alignment status of a device
+ */
+#ifdef BLKALIGNOFF
+int blkdev_is_misaligned(int fd)
+{
+	int aligned;
+
+	if (ioctl(fd, BLKALIGNOFF, &aligned) < 0)
+		return 0;			/* probably kernel < 2.6.32 */
+	/*
+	 * Note that kernel returns -1 as alignment offset if no compatible
+	 * sizes and alignments exist for stacked devices
+	 */
+	return aligned != 0 ? 1 : 0;
+}
+#else
+int blkdev_is_misaligned(int fd __attribute__((__unused__)))
+{
+	return 0;
+}
+#endif
+
+int open_blkdev_or_file(const struct stat *st, const char *name, const int oflag)
+{
+	int fd;
+
+	if (S_ISBLK(st->st_mode)) {
+		fd = open(name, oflag | O_EXCL);
+	} else
+		fd = open(name, oflag);
+	if (-1 < fd && !is_same_inode(fd, st)) {
+		close(fd);
+		errno = EBADFD;
+		return -1;
+	}
+	if (-1 < fd && S_ISBLK(st->st_mode) && blkdev_is_misaligned(fd))
+		warnx(_("warning: %s is misaligned"), name);
+	return fd;
+}
+
+#ifdef CDROM_GET_CAPABILITY
+int blkdev_is_cdrom(int fd)
+{
+	int ret;
+
+	if ((ret = ioctl(fd, CDROM_GET_CAPABILITY, NULL)) < 0)
+		return 0;
+
+	return ret;
+}
+#else
+int blkdev_is_cdrom(int fd __attribute__((__unused__)))
+{
+	return 0;
+}
+#endif
+
+/*
+ * Get kernel's interpretation of the device's geometry.
+ *
+ * Returns the heads and sectors - but not cylinders
+ * as it's truncated for disks with more than 65535 tracks.
+ *
+ * Note that this is deprecated in favor of LBA addressing.
+ */
+#ifdef HDIO_GETGEO
+int blkdev_get_geometry(int fd, unsigned int *h, unsigned int *s)
+{
+	struct hd_geometry geometry;
+
+	if (ioctl(fd, HDIO_GETGEO, &geometry) == 0) {
+		*h = geometry.heads;
+		*s = geometry.sectors;
+		return 0;
+	}
+#else
+int blkdev_get_geometry(int fd __attribute__((__unused__)),
+		unsigned int *h, unsigned int *s)
+{
+	*h = 0;
+	*s = 0;
+#endif
+	return -1;
+}
+
+/*
+ * Convert scsi type to human readable string.
+ */
+const char *blkdev_scsi_type_to_name(int type)
+{
+	switch (type) {
+	case SCSI_TYPE_DISK:
+		return "disk";
+	case SCSI_TYPE_TAPE:
+		return "tape";
+	case SCSI_TYPE_PRINTER:
+		return "printer";
+	case SCSI_TYPE_PROCESSOR:
+		return "processor";
+	case SCSI_TYPE_WORM:
+		return "worm";
+	case SCSI_TYPE_ROM:
+		return "rom";
+	case SCSI_TYPE_SCANNER:
+		return "scanner";
+	case SCSI_TYPE_MOD:
+		return "mo-disk";
+	case SCSI_TYPE_MEDIUM_CHANGER:
+		return "changer";
+	case SCSI_TYPE_COMM:
+		return "comm";
+	case SCSI_TYPE_RAID:
+		return "raid";
+	case SCSI_TYPE_ENCLOSURE:
+		return "enclosure";
+	case SCSI_TYPE_RBC:
+		return "rbc";
+	case SCSI_TYPE_OSD:
+		return "osd";
+	case SCSI_TYPE_NO_LUN:
+		return "no-lun";
+	default:
+		break;
+	}
+	return NULL;
+}
+
+/* return 0 on success */
+int blkdev_lock(int fd, const char *devname, const char *lockmode)
+{
+	int oper, rc, msg = 0;
+
+	if (!lockmode)
+		lockmode = getenv("LOCK_BLOCK_DEVICE");
+	if (!lockmode)
+		return 0;
+
+	if (strcasecmp(lockmode, "yes") == 0 ||
+	    strcmp(lockmode, "1") == 0)
+		oper = LOCK_EX;
+
+	else if (strcasecmp(lockmode, "nonblock") == 0)
+		oper = LOCK_EX | LOCK_NB;
+
+	else if (strcasecmp(lockmode, "no") == 0 ||
+		 strcmp(lockmode, "0") == 0)
+		return 0;
+	else {
+		warnx(_("unsupported lock mode: %s"), lockmode);
+		return -EINVAL;
+	}
+
+	if (!(oper & LOCK_NB)) {
+		/* Try non-block first to provide message */
+		rc = flock(fd, oper | LOCK_NB);
+		if (rc == 0)
+			return 0;
+		if (rc != 0 && errno == EWOULDBLOCK) {
+			fprintf(stderr, _("%s: %s: device already locked, waiting to get lock ... "),
+					program_invocation_short_name, devname);
+			msg = 1;
+		}
+	}
+	rc = flock(fd, oper);
+	if (rc != 0) {
+		switch (errno) {
+		case EWOULDBLOCK: /* LOCK_NB */
+			warnx(_("%s: device already locked"), devname);
+			break;
+		default:
+			warn(_("%s: failed to get lock"), devname);
+		}
+	} else if (msg)
+		fprintf(stderr, _("OK\n"));
+	return rc;
+}
+
+
+#ifdef TEST_PROGRAM_BLKDEV
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+int
+main(int argc, char **argv)
+{
+	unsigned long long bytes;
+	unsigned long long sectors;
+	int sector_size, phy_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|O_CLOEXEC)) < 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");
+	if (blkdev_get_physector_size(fd, &phy_sector_size) < 0)
+		err(EXIT_FAILURE, "blkdev_get_physector_size() failed");
+
+	printf("          bytes: %llu\n", bytes);
+	printf("        sectors: %llu\n", sectors);
+	printf("    sector size: %d\n", sector_size);
+	printf("phy-sector size: %d\n", phy_sector_size);
+
+	return EXIT_SUCCESS;
+}
+#endif /* TEST_PROGRAM_BLKDEV */