-
-/*
- * convert a major/minor pair for a block device into a name in /dev, if possible.
- * On the first call, walk /dev collecting name.
- * Put them in a simple linked listfor now.
- */
-struct devmap {
- int major, minor;
- char *name;
- struct devmap *next;
-} *devlist = NULL;
-int devlist_ready = 0;
-
-int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
-{
- struct stat st;
-
- if (S_ISLNK(stb->st_mode)) {
- if (stat(name, &st) != 0)
- return 0;
- stb = &st;
- }
-
- if ((stb->st_mode&S_IFMT)== S_IFBLK) {
- char *n = strdup(name);
- struct devmap *dm = malloc(sizeof(*dm));
- if (strncmp(n, "/dev/./", 7)==0)
- strcpy(n+4, name+6);
- if (dm) {
- dm->major = major(stb->st_rdev);
- dm->minor = minor(stb->st_rdev);
- dm->name = n;
- dm->next = devlist;
- devlist = dm;
- }
- }
- return 0;
-}
-
-#ifndef HAVE_NFTW
-#ifdef HAVE_FTW
-int add_dev_1(const char *name, const struct stat *stb, int flag)
-{
- return add_dev(name, stb, flag, NULL);
-}
-int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
-{
- return ftw(path, add_dev_1, nopenfd);
-}
-#else
-int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
-{
- return 0;
-}
-#endif /* HAVE_FTW */
-#endif /* HAVE_NFTW */
-
-/*
- * Find a block device with the right major/minor number.
- * If we find multiple names, choose the shortest.
- * If we find a name in /dev/md/, we prefer that.
- * This applies only to names for MD devices.
- */
-char *map_dev(int major, int minor, int create)
-{
- struct devmap *p;
- char *regular = NULL, *preferred=NULL;
- int did_check = 0;
-
- if (major == 0 && minor == 0)
- return NULL;
-
- retry:
- if (!devlist_ready) {
- char *dev = "/dev";
- struct stat stb;
- while(devlist) {
- struct devmap *d = devlist;
- devlist = d->next;
- free(d->name);
- free(d);
- }
- if (lstat(dev, &stb)==0 &&
- S_ISLNK(stb.st_mode))
- dev = "/dev/.";
- nftw(dev, add_dev, 10, FTW_PHYS);
- devlist_ready=1;
- did_check = 1;
- }
-
- for (p=devlist; p; p=p->next)
- if (p->major == major &&
- p->minor == minor) {
- if (strncmp(p->name, "/dev/md/",8) == 0) {
- if (preferred == NULL ||
- strlen(p->name) < strlen(preferred))
- preferred = p->name;
- } else {
- if (regular == NULL ||
- strlen(p->name) < strlen(regular))
- regular = p->name;
- }
- }
- if (!regular && !preferred && !did_check) {
- devlist_ready = 0;
- goto retry;
- }
- if (create && !regular && !preferred) {
- static char buf[30];
- snprintf(buf, sizeof(buf), "%d:%d", major, minor);
- regular = buf;
- }
-
- return preferred ? preferred : regular;
-}
-