* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ * Copyright (C) 2005 by Rob Landley <rob@landley.net>
*
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-
-
-#include <features.h>
-#include <stdio.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/ioctl.h>
#include "libbb.h"
-
-/* For 2.6, use the cleaned up header to get the 64 bit API. */
#include <linux/version.h>
+
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-#include <linux/loop.h>
+
+/* For 2.6, use the cleaned up header to get the 64 bit API. */
+// Commented out per Rob's request
+//# include "fix_u32.h" /* some old toolchains need __u64 for linux/loop.h */
+# include <linux/loop.h>
typedef struct loop_info64 bb_loop_info;
-#define BB_LOOP_SET_STATUS LOOP_SET_STATUS64
-#define BB_LOOP_GET_STATUS LOOP_GET_STATUS64
+# define BB_LOOP_SET_STATUS LOOP_SET_STATUS64
+# define BB_LOOP_GET_STATUS LOOP_GET_STATUS64
-/* For 2.4 and earlier, use the 32 bit API (and don't trust the headers) */
#else
-/* Stuff stolen from linux/loop.h for 2.4 and earlier kernels*/
-#include <linux/posix_types.h>
-#define LO_NAME_SIZE 64
-#define LO_KEY_SIZE 32
-#define LOOP_SET_FD 0x4C00
-#define LOOP_CLR_FD 0x4C01
-#define BB_LOOP_SET_STATUS 0x4C02
-#define BB_LOOP_GET_STATUS 0x4C03
+
+/* For 2.4 and earlier, use the 32 bit API (and don't trust the headers) */
+/* Stuff stolen from linux/loop.h for 2.4 and earlier kernels */
+# include <linux/posix_types.h>
+# define LO_NAME_SIZE 64
+# define LO_KEY_SIZE 32
+# define LOOP_SET_FD 0x4C00
+# define LOOP_CLR_FD 0x4C01
+# define BB_LOOP_SET_STATUS 0x4C02
+# define BB_LOOP_GET_STATUS 0x4C03
typedef struct {
int lo_number;
__kernel_dev_t lo_device;
} bb_loop_info;
#endif
-char *query_loop(const char *device)
+char* FAST_FUNC query_loop(const char *device)
{
int fd;
bb_loop_info loopinfo;
- char *dev=0;
-
- if ((fd = open(device, O_RDONLY)) < 0) return 0;
- if (!ioctl(fd, BB_LOOP_GET_STATUS, &loopinfo))
- dev=bb_xasprintf("%ld %s", (long) loopinfo.lo_offset,
- loopinfo.lo_file_name);
- close(fd);
+ char *dev = NULL;
- return dev;
-}
+ fd = open(device, O_RDONLY);
+ if (fd >= 0) {
+ if (ioctl(fd, BB_LOOP_GET_STATUS, &loopinfo) == 0) {
+ dev = xasprintf("%"OFF_FMT"u %s", (off_t) loopinfo.lo_offset,
+ (char *)loopinfo.lo_file_name);
+ }
+ close(fd);
+ }
+ return dev;
+}
-int del_loop(const char *device)
+int FAST_FUNC del_loop(const char *device)
{
int fd, rc;
- if ((fd = open(device, O_RDONLY)) < 0) return 1;
- rc=ioctl(fd, LOOP_CLR_FD, 0);
+ fd = open(device, O_RDONLY);
+ if (fd < 0)
+ return 1;
+ rc = ioctl(fd, LOOP_CLR_FD, 0);
close(fd);
-
+
return rc;
}
search will re-use an existing loop device already bound to that
file/offset if it finds one.
*/
-int set_loop(char **device, const char *file, int offset)
+int FAST_FUNC set_loop(char **device, const char *file, unsigned long long offset)
{
- char dev[20], *try;
+ char dev[LOOP_NAMESIZE];
+ char *try;
bb_loop_info loopinfo;
struct stat statbuf;
- int i, dfd, ffd, mode, rc=-1;
+ int i, dfd, ffd, mode, rc = -1;
/* Open the file. Barf if this doesn't work. */
- if((ffd = open(file, mode=O_RDWR))<0 && (ffd = open(file,mode=O_RDONLY))<0)
- return errno;
+ mode = O_RDWR;
+ ffd = open(file, mode);
+ if (ffd < 0) {
+ mode = O_RDONLY;
+ ffd = open(file, mode);
+ if (ffd < 0)
+ return -errno;
+ }
/* Find a loop device. */
- try=*device ? : dev;
- for(i=0;rc;i++) {
+ try = *device ? *device : dev;
+ /* 1048575 is a max possible minor number in Linux circa 2010 */
+ for (i = 0; rc && i < 1048576; i++) {
sprintf(dev, LOOP_FORMAT, i);
- /* Ran out of block devices, return failure. */
- if(stat(try, &statbuf) || !S_ISBLK(statbuf.st_mode)) {
- rc=ENOENT;
+
+ IF_FEATURE_MOUNT_LOOP_CREATE(errno = 0;)
+ if (stat(try, &statbuf) != 0 || !S_ISBLK(statbuf.st_mode)) {
+ if (ENABLE_FEATURE_MOUNT_LOOP_CREATE
+ && errno == ENOENT
+ && try == dev
+ ) {
+ /* Node doesn't exist, try to create it. */
+ if (mknod(dev, S_IFBLK|0644, makedev(7, i)) == 0)
+ goto try_to_open;
+ }
+ /* Ran out of block devices, return failure. */
+ rc = -ENOENT;
break;
}
+ try_to_open:
/* Open the sucker and check its loopiness. */
- if((dfd=open(try, mode))<0 && errno==EROFS)
- dfd=open(try,mode=O_RDONLY);
- if(dfd<0) goto try_again;
+ dfd = open(try, mode);
+ if (dfd < 0 && errno == EROFS) {
+ mode = O_RDONLY;
+ dfd = open(try, mode);
+ }
+ if (dfd < 0)
+ goto try_again;
- rc=ioctl(dfd, BB_LOOP_GET_STATUS, &loopinfo);
+ rc = ioctl(dfd, BB_LOOP_GET_STATUS, &loopinfo);
- /* If device free, claim it. */
- if(rc && errno==ENXIO) {
+ /* If device is free, claim it. */
+ if (rc && errno == ENXIO) {
memset(&loopinfo, 0, sizeof(loopinfo));
- safe_strncpy(loopinfo.lo_file_name, file, LO_NAME_SIZE);
+ safe_strncpy((char *)loopinfo.lo_file_name, file, LO_NAME_SIZE);
loopinfo.lo_offset = offset;
/* Associate free loop device with file. */
- if(!ioctl(dfd, LOOP_SET_FD, ffd) &&
- !ioctl(dfd, BB_LOOP_SET_STATUS, &loopinfo)) rc=0;
- else ioctl(dfd, LOOP_CLR_FD, 0);
+ if (ioctl(dfd, LOOP_SET_FD, ffd) == 0) {
+ if (ioctl(dfd, BB_LOOP_SET_STATUS, &loopinfo) == 0)
+ rc = 0;
+ else
+ ioctl(dfd, LOOP_CLR_FD, 0);
+ }
+
/* If this block device already set up right, re-use it.
(Yes this is racy, but associating two loop devices with the same
file isn't pretty either. In general, mounting the same file twice
without using losetup manually is problematic.)
*/
- } else if(strcmp(file,loopinfo.lo_file_name)
- || offset!=loopinfo.lo_offset) rc=-1;
+ } else
+ if (strcmp(file, (char *)loopinfo.lo_file_name) != 0
+ || offset != loopinfo.lo_offset
+ ) {
+ rc = -1;
+ }
close(dfd);
-try_again:
- if(*device) break;
+ try_again:
+ if (*device) break;
}
close(ffd);
- if(!rc) {
- if(!*device) *device=strdup(dev);
- return mode==O_RDONLY ? 1 : 0;
- } else return rc;
+ if (rc == 0) {
+ if (!*device)
+ *device = xstrdup(dev);
+ return (mode == O_RDONLY); /* 1:ro, 0:rw */
+ }
+ return rc;
}
-
-/* END CODE */
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
projects / oweals / busybox.git / blobdiff