/*
* Utility routines.
*
- * Copyright (C) tons of folks. Tracking down who wrote what
- * isn't something I'm going to worry about... If you wrote something
- * here, please feel free to acknowledge your work.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Based in part on code from sash, Copyright (c) 1999 by David I. Bell
- * Permission has been granted to redistribute this code under the GPL.
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-#include <stdio.h>
-#include <string.h>
-#include <dirent.h>
-#include <stdlib.h>
#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];
+};
-extern char *find_real_root_device_name(const char* name)
+static char *find_block_device_in_dir(struct arena *ap)
{
DIR *dir;
struct dirent *entry;
- struct stat statBuf, rootStat;
- char *fileName;
- dev_t dev;
+ char *retpath = NULL;
+ int len, rem;
- if (stat("/", &rootStat) != 0) {
- perror_msg("could not stat '/'");
+ dir = opendir(ap->devpath);
+ if (!dir)
return NULL;
- }
- if ((dev = rootStat.st_rdev)==0) dev=rootStat.st_dev;
-
- dir = opendir("/dev");
- if (!dir) {
- perror_msg("could not open '/dev'");
- goto fallback;
- }
- while((entry = readdir(dir)) != NULL) {
+ len = strlen(ap->devpath);
+ rem = DEVNAME_MAX-2 - len;
+ if (rem <= 0)
+ return NULL;
+ ap->devpath[len++] = '/';
- /* Must skip ".." since that is "/", and so we
- * would get a false positive on ".." */
- if (strcmp(entry->d_name, "..") == 0)
+ 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;
-
- fileName = concat_path_file("/dev/", entry->d_name);
-
- /* Some char devices have the same dev_t as block
- * devices, so make sure this is a block device */
- if (stat(fileName, &statBuf) == 0 &&
- S_ISBLK(statBuf.st_mode)!=0 &&
- statBuf.st_rdev == dev) {
- return fileName;
+ 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;
}
- free(fileName);
}
closedir(dir);
-fallback:
- /* don't use stack space, caller expects to free() result */
- fileName=xmalloc(20);
- sprintf(fileName,"(rdev %u)",(unsigned int) rootStat.st_rdev);
- return fileName;
+ return retpath;
}
+char* FAST_FUNC find_block_device(const char *path)
+{
+ struct arena a;
-/* END CODE */
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+ 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);
+}