---

 kpartx/lopart.c |  206 ++++++++++++++++++++++++++++++++++----------------------

 1 file changed, 127 insertions(+), 79 deletions(-)

Index: multipath-tools-130222/kpartx/lopart.c

===================================================================

--- multipath-tools-130222.orig/kpartx/lopart.c

+++ multipath-tools-130222/kpartx/lopart.c

@@ -25,8 +25,9 @@

 #include <sys/ioctl.h>

 #include <sys/stat.h>

 #include <sys/mman.h>

+#include <sys/types.h>

+#include <dirent.h>

 #include <sysmacros.h>

-#include <asm/posix_types.h>

 #include <linux/loop.h>

 #include "lopart.h"

@@ -96,97 +97,149 @@ is_loop_device (const char *device)

 #define SIZE(a) (sizeof(a)/sizeof(a[0]))

 extern char *

-find_loop_by_file (const char * filename)

+find_loop_by_file(const char *filename)

 {

-	char dev[64];

-	char *loop_formats[] = { "/dev/loop%d", "/dev/loop/%d" };

-	int i, j, fd;

+	DIR *dir;

+	struct dirent *dent;

+	char dev[64], *found = NULL, *p;

+	int fd, bytes_read;

 	struct stat statbuf;

 	struct loop_info loopinfo;

+	const char VIRT_BLOCK[] = "/sys/devices/virtual/block";

+	char path[PATH_MAX];

+	char bf_path[PATH_MAX];

+	char backing_file[PATH_MAX];

-	for (j = 0; j < SIZE(loop_formats); j++) {

+	dir = opendir(VIRT_BLOCK);

+	if (!dir)

+		return NULL;

-		for (i = 0; i < 256; i++) {

-			sprintf (dev, loop_formats[j], i);

+	while ((dent = readdir(dir)) != NULL) {

+		if (strncmp(dent->d_name,"loop",4))

+			continue;

-			if (stat (dev, &statbuf) != 0 ||

-			    !S_ISBLK(statbuf.st_mode))

-				continue;

+		if (snprintf(path, PATH_MAX, "%s/%s/dev", VIRT_BLOCK,

+					dent->d_name) >= PATH_MAX)

+			continue;

-			fd = open (dev, O_RDONLY);

+		fd = open(path, O_RDONLY);

+		if (fd < 0)

+			continue;

-			if (fd < 0)

-				break;

+		bytes_read = read(fd, dev, sizeof(dev) - 1);

+		if (bytes_read <= 0) {

+			close(fd);

+			continue;

+		}

-			if (ioctl (fd, LOOP_GET_STATUS, &loopinfo) != 0) {

-				close (fd);

-				continue;

-			}

+		close(fd);

-			if (0 == strcmp(filename, loopinfo.lo_name)) {

-				close (fd);

-				return xstrdup(dev); /*found */

-			}

+		dev[bytes_read] = '\0';

+		p = strchr(dev, '\n');

+		if (p != NULL)

+			*p = '\0';

+		if (snprintf(path, PATH_MAX, "/dev/block/%s", dev) >= PATH_MAX)

+			continue;

+		fd = open (path, O_RDONLY);

+		if (fd < 0)

+			continue;

+

+		if (fstat (fd, &statbuf) != 0 ||

+		    !S_ISBLK(statbuf.st_mode)) {

+			close (fd);

+			continue;

+		}

+

+		if (ioctl (fd, LOOP_GET_STATUS, &loopinfo) != 0) {

 			close (fd);

 			continue;

 		}

+

+		close (fd);

+

+		if (0 == strcmp(filename, loopinfo.lo_name)) {

+			found = realpath(path, NULL);

+			break;

+		}

+

+		/*

+		 * filename is a realpath, while loopinfo.lo_name may hold just the

+		 * basename.  If that's the case, try to match filename against the

+		 * backing_file entry for this loop entry

+		 */

+		if (snprintf(bf_path, PATH_MAX, "%s/%s/loop/backing_file",

+			     VIRT_BLOCK, dent->d_name) >= PATH_MAX)

+			continue;

+

+		fd = open(bf_path, O_RDONLY);

+		if (fd < 0)

+			continue;

+

+		bytes_read = read(fd, backing_file, sizeof(backing_file) - 1);

+		if (bytes_read <= 0) {

+			close(fd);

+			continue;

+		}

+

+		close(fd);

+

+		backing_file[bytes_read-1] = '\0';

+

+		if (0 == strcmp(filename, backing_file)) {

+			found = realpath(path, NULL);

+			break;

+		}

 	}

-	return NULL;

+	closedir(dir);

+	return found;

 }

 extern char *

-find_unused_loop_device (void)

+find_unused_loop_device(void)

 {

-	/* Just creating a device, say in /tmp, is probably a bad idea -

-	   people might have problems with backup or so.

-	   So, we just try /dev/loop[0-7]. */

-

-	char dev[20];

-	char *loop_formats[] = { "/dev/loop%d", "/dev/loop/%d" };

-	int i, j, fd, first = 0, somedev = 0, someloop = 0, loop_known = 0;

+	char dev[20], *next_loop_dev = NULL;

+	int fd, next_loop = 0, somedev = 0, someloop = 0, loop_known = 0;

 	struct stat statbuf;

 	struct loop_info loopinfo;

 	FILE *procdev;

-	if (stat("/dev/loop-control", &statbuf) == 0 &&

-	    S_ISCHR(statbuf.st_mode)) {

-		fd = open("/dev/loop-control", O_RDWR);

-		if (fd >= 0) {

-			first = ioctl(fd, LOOP_CTL_GET_FREE);

-			close(fd);

+	while (next_loop_dev == NULL) {

+		if (stat("/dev/loop-control", &statbuf) == 0 &&

+		    S_ISCHR(statbuf.st_mode)) {

+			int next_loop_fd;

+

+			next_loop_fd = open("/dev/loop-control", O_RDWR);

+			if (next_loop_fd < 0)

+				return NULL;

+			next_loop = ioctl(next_loop_fd, LOOP_CTL_GET_FREE);

+			close(next_loop_fd);

+			if (next_loop < 0)

+				return NULL;

 		}

-		if (first < 0)

-			first = 0;

-	}

-	for (j = 0; j < SIZE(loop_formats); j++) {

-

-	    for(i = first; i < 256; i++) {

-		sprintf(dev, loop_formats[j], i);

-

-		if (stat (dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {

-			somedev++;

-			fd = open (dev, O_RDONLY);

-			if (fd >= 0) {

+		sprintf(dev, "/dev/loop%d", next_loop);

+		fd = open (dev, O_RDONLY);

+		if (fd >= 0) {

+			if (fstat (fd, &statbuf) == 0 &&

+			    S_ISBLK(statbuf.st_mode)) {

+				somedev++;

 				if(ioctl (fd, LOOP_GET_STATUS, &loopinfo) == 0)

-					someloop++;		/* in use */

-

-				else if (errno == ENXIO) {

-					close (fd);

-					return xstrdup(dev);/* probably free */

-				}

+					someloop++;             /* in use */

+				else if (errno == ENXIO)

+					next_loop_dev = xstrdup(dev);

-				close (fd);

 			}

-			

+			close (fd);

+

 			/* continue trying as long as devices exist */

 			continue;

 		}

 		break;

-	    }

 	}

+	if (next_loop_dev)

+		return next_loop_dev;

 	/* Nothing found. Why not? */

 	if ((procdev = fopen(PROC_DEVICES, "r")) != NULL) {

@@ -209,29 +262,24 @@ find_unused_loop_device (void)

 		fprintf(stderr, "mount: could not find any device /dev/loop#");

 	else if (!someloop) {

-

-	    if (loop_known == 1)

-		fprintf(stderr,

-		    "mount: Could not find any loop device.\n"

-		    "       Maybe /dev/loop# has a wrong major number?");

-	    

-	    else if (loop_known == -1)

-		fprintf(stderr,

-		    "mount: Could not find any loop device, and, according to %s,\n"

-		    "       this kernel does not know about the loop device.\n"

-		    "       (If so, then recompile or `modprobe loop'.)",

-		      PROC_DEVICES);

-

-	    else

-		fprintf(stderr,

-		    "mount: Could not find any loop device. Maybe this kernel does not know\n"

-		    "       about the loop device (then recompile or `modprobe loop'), or\n"

-		    "       maybe /dev/loop# has the wrong major number?");

-

+		if (loop_known == 1)

+			fprintf(stderr,

+				"mount: Could not find any loop device.\n"

+				"       Maybe /dev/loop# has a wrong major number?");

+		else if (loop_known == -1)

+			fprintf(stderr,

+				"mount: Could not find any loop device, and, according to %s,\n"

+				"       this kernel does not know about the loop device.\n"

+				"       (If so, then recompile or `modprobe loop'.)",

+				PROC_DEVICES);

+		else

+			fprintf(stderr,

+				"mount: Could not find any loop device. Maybe this kernel does not know\n"

+				"       about the loop device (then recompile or `modprobe loop'), or\n"

+				"       maybe /dev/loop# has the wrong major number?");

 	} else

 		fprintf(stderr, "mount: could not find any free loop device");

-	

-	return 0;

+	return NULL;

 }

 extern int