76 lines
1.7 KiB
C
76 lines
1.7 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Utility routines.
|
|
*
|
|
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
|
*/
|
|
|
|
#include "libbb.h"
|
|
|
|
/* Find block device /dev/XXX which contains specified file
|
|
* We handle /dev/dir/dir/dir too, at a cost of ~80 more bytes code */
|
|
|
|
/* Do not reallocate all this stuff on each recursion */
|
|
enum { DEVNAME_MAX = 256 };
|
|
struct arena {
|
|
struct stat st;
|
|
dev_t dev;
|
|
/* Was PATH_MAX, but we recurse _/dev_. We can assume
|
|
* people are not crazy enough to have mega-deep tree there */
|
|
char devpath[DEVNAME_MAX];
|
|
};
|
|
|
|
static char *find_block_device_in_dir(struct arena *ap)
|
|
{
|
|
DIR *dir;
|
|
struct dirent *entry;
|
|
char *retpath = NULL;
|
|
int len, rem;
|
|
|
|
len = strlen(ap->devpath);
|
|
rem = DEVNAME_MAX-2 - len;
|
|
if (rem <= 0)
|
|
return NULL;
|
|
|
|
dir = opendir(ap->devpath);
|
|
if (!dir)
|
|
return NULL;
|
|
|
|
ap->devpath[len++] = '/';
|
|
|
|
while ((entry = readdir(dir)) != NULL) {
|
|
safe_strncpy(ap->devpath + len, entry->d_name, rem);
|
|
/* lstat: do not follow links */
|
|
if (lstat(ap->devpath, &ap->st) != 0)
|
|
continue;
|
|
if (S_ISBLK(ap->st.st_mode) && ap->st.st_rdev == ap->dev) {
|
|
retpath = xstrdup(ap->devpath);
|
|
break;
|
|
}
|
|
if (S_ISDIR(ap->st.st_mode)) {
|
|
/* Do not recurse for '.' and '..' */
|
|
if (DOT_OR_DOTDOT(entry->d_name))
|
|
continue;
|
|
retpath = find_block_device_in_dir(ap);
|
|
if (retpath)
|
|
break;
|
|
}
|
|
}
|
|
closedir(dir);
|
|
|
|
return retpath;
|
|
}
|
|
|
|
char* FAST_FUNC find_block_device(const char *path)
|
|
{
|
|
struct arena a;
|
|
|
|
if (stat(path, &a.st) != 0)
|
|
return NULL;
|
|
a.dev = S_ISBLK(a.st.st_mode) ? a.st.st_rdev : a.st.st_dev;
|
|
strcpy(a.devpath, "/dev");
|
|
return find_block_device_in_dir(&a);
|
|
}
|