Update the loop handling code to support more than 256
devices.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
kpartx/lopart.c | 106 ++++++++++++++++++++++++++------------------------------
1 file changed, 49 insertions(+), 57 deletions(-)
diff --git a/kpartx/lopart.c b/kpartx/lopart.c
index 26f3011..ffde6d9 100644
--- a/kpartx/lopart.c
+++ b/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"
@@ -98,78 +99,71 @@ is_loop_device (const char *device)
extern char *
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;
+ int fd;
struct stat statbuf;
struct loop_info loopinfo;
- dev_t file_dev;
- ino_t file_ino;
- if (stat (filename, &statbuf) != 0) {
+ dir = opendir("/dev");
+ if (!dir)
return NULL;
- }
- file_dev = statbuf.st_dev;
- file_ino = statbuf.st_ino;
-
- for (j = 0; j < SIZE(loop_formats); j++) {
-
- for (i = 0; i < 256; i++) {
- sprintf (dev, loop_formats[j], i);
-
- if (stat (dev, &statbuf) != 0 ||
- !S_ISBLK(statbuf.st_mode))
- continue;
-
- fd = open (dev, O_RDONLY);
- if (fd < 0)
- break;
+ while ((dent = readdir(dir)) != NULL) {
+ if (strncmp(dent->d_name,"loop",4))
+ continue;
+ if (!strcmp(dent->d_name, "loop-control"))
+ continue;
+ sprintf(dev, "/dev/%s", dent->d_name);
- if (ioctl (fd, LOOP_GET_STATUS, &loopinfo) != 0) {
- close (fd);
- continue;
- }
+ if (stat (dev, &statbuf) != 0 ||
+ !S_ISBLK(statbuf.st_mode))
+ continue;
- if (loopinfo.lo_device == file_dev && loopinfo.lo_inode == file_ino) {
- close (fd);
- return xstrdup(dev); /*found */
- }
+ fd = open (dev, O_RDONLY);
+ if (fd < 0)
+ break;
+ if (ioctl (fd, LOOP_GET_STATUS, &loopinfo) != 0) {
close (fd);
continue;
}
+
+ if (0 == strcmp(filename, loopinfo.lo_name)) {
+ close (fd);
+ found = xstrdup(dev);
+ break;
+ }
+
+ close (fd);
}
- return NULL;
+ closedir(dir);
+ return found;
}
extern char *
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);
- if (first < 0)
- first = 0;
- }
- for (j = 0; j < SIZE(loop_formats); j++) {
+ while (next_loop_dev == NULL) {
+ if (stat("/dev/loop-control", &statbuf) == 0 &&
+ S_ISCHR(statbuf.st_mode)) {
+ fd = open("/dev/loop-control", O_RDWR);
+ if (fd < 0)
+ return NULL;
+ next_loop = ioctl(fd, LOOP_CTL_GET_FREE);
+ if (next_loop < 0)
+ return NULL;
+ close(fd);
+ }
- for(i = first; i < 256; i++) {
- sprintf(dev, loop_formats[j], i);
+ sprintf(dev, "/dev/loop%d", next_loop);
if (stat (dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
somedev++;
@@ -182,18 +176,19 @@ find_unused_loop_device (void)
else if (errno == ENXIO) {
close (fd);
- return xstrdup(dev);/* probably free */
+ next_loop_dev = xstrdup(dev);
}
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) {
@@ -216,12 +211,10 @@ 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"
@@ -237,7 +230,6 @@ find_unused_loop_device (void)
} else
fprintf(stderr, "mount: could not find any free loop device");
-
return 0;
}
--
2.6.6
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