/*
* Utility routines.
*
- * Copyright (C) 1999-200
3 by Erik Andersen <andersen@codepoet.org>
+ * Copyright (C) 1999-200
4 by Erik Andersen <andersen@codepoet.org>
*
- * 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
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
+
+#include <features.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include "libbb.h"
-/* Grumble... The 2.6.x kernel breaks asm/posix_types.h
- * so we get to try and cope as best we can... */
+/* For 2.6, use the cleaned up header to get the 64 bit API. */
#include <linux/version.h>
-#include <asm/posix_types.h>
-#if LINUX_VERSION_CODE >= 132608
-#define __bb_kernel_dev_t __kernel_old_dev_t
-#elif LINUX_VERSION_CODE >= 0x20600
-#define __bb_kernel_dev_t __kernel_dev_t
-#else
-#define __bb_kernel_dev_t unsigned short
-#endif
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
+#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
-/* Stuff stolen from linux/loop.h */
+/* 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 LOOP_SET_STATUS 0x4C02
-#define LOOP_GET_STATUS 0x4C03
-struct loop_info {
+#define BB_LOOP_SET_STATUS 0x4C02
+#define BB_LOOP_GET_STATUS 0x4C03
+typedef struct {
int lo_number;
- __bb_kernel_dev_t lo_device;
+ __kernel_dev_t lo_device;
unsigned long lo_inode;
- __bb_kernel_dev_t lo_rdevice;
+ __kernel_dev_t lo_rdevice;
int lo_offset;
int lo_encrypt_type;
int lo_encrypt_key_size;
int lo_flags;
- char lo_name[LO_NAME_SIZE];
+ char lo_file_name[LO_NAME_SIZE];
unsigned char lo_encrypt_key[LO_KEY_SIZE];
unsigned long lo_init[2];
char reserved[4];
-};
+} bb_loop_info;
+#endif
-extern int del_loop(const char *device)
+char *query_loop(const char *device)
{
int fd;
+ bb_loop_info loopinfo;
+ char *dev=0;
- if ((fd = open(device, O_RDONLY)) < 0) {
- bb_perror_msg("%s", device);
- return (FALSE);
- }
- if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
- close(fd);
- bb_perror_msg("ioctl: LOOP_CLR_FD");
- return (FALSE);
- }
+ 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,
+ (char *)loopinfo.lo_file_name);
close(fd);
- return (TRUE);
-}
-extern int set_loop(const char *device, const char *file, int offset,
- int *loopro)
-{
- struct loop_info loopinfo;
- int fd, ffd, mode;
-
- mode = *loopro ? O_RDONLY : O_RDWR;
- if ((ffd = open(file, mode)) < 0 && !*loopro
- && (errno != EROFS || (ffd = open(file, mode = O_RDONLY)) < 0)) {
- bb_perror_msg("%s", file);
- return 1;
- }
- if ((fd = open(device, mode)) < 0) {
- close(ffd);
- bb_perror_msg("%s", device);
- return 1;
- }
- *loopro = (mode == O_RDONLY);
+ return dev;
+}
- memset(&loopinfo, 0, sizeof(loopinfo));
- safe_strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
- loopinfo.lo_offset = offset;
+int del_loop(const char *device)
+{
+ int fd, rc;
- loopinfo.lo_encrypt_key_size = 0;
- if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
- bb_perror_msg("ioctl: LOOP_SET_FD");
- close(fd);
- close(ffd);
- return 1;
- }
- if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
- (void) ioctl(fd, LOOP_CLR_FD, 0);
- bb_perror_msg("ioctl: LOOP_SET_STATUS");
- close(fd);
- close(ffd);
- return 1;
- }
+ if ((fd = open(device, O_RDONLY)) < 0) return 1;
+ rc=ioctl(fd, LOOP_CLR_FD, 0);
close(fd);
- close(ffd);
- return 0;
+
+ return rc;
}
-extern char *find_unused_loop_device(void)
+/* Returns 0 if mounted RW, 1 if mounted read-only, <0 for error.
+ *device is loop device to use, or if *device==NULL finds a loop device to
+ mount it on and sets *device to a strdup of that loop device name. This
+ 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)
{
- char dev[20];
- int i, fd;
+ char dev[20], *try;
+ bb_loop_info loopinfo;
struct stat statbuf;
- struct loop_info loopinfo;
+ 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;
- for (i = 0; i <= 7; i++) {
+ /* Find a loop device. */
+ try=*device ? : dev;
+ for(i=0;rc;i++) {
sprintf(dev, LOOP_FORMAT, i);
- if (stat(dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
- if ((fd = open(dev, O_RDONLY)) >= 0) {
- if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) != 0) {
- if (errno == ENXIO) { /* probably free */
- close(fd);
- return strdup(dev);
- }
- }
- close(fd);
- }
+
+ /* Ran out of block devices, return failure. */
+ if(stat(try, &statbuf) || !S_ISBLK(statbuf.st_mode)) {
+ rc=-ENOENT;
+ break;
}
- }
- return NULL;
-}
+ /* 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;
+ rc=ioctl(dfd, BB_LOOP_GET_STATUS, &loopinfo);
-/* END CODE */
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+ /* If device free, claim it. */
+ if(rc && errno==ENXIO) {
+ memset(&loopinfo, 0, sizeof(loopinfo));
+ 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 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,(char *)loopinfo.lo_file_name)
+ || offset!=loopinfo.lo_offset) rc=-1;
+ close(dfd);
+try_again:
+ if(*device) break;
+ }
+ close(ffd);
+ if(!rc) {
+ if(!*device) *device=strdup(dev);
+ return mode==O_RDONLY ? 1 : 0;
+ } else return rc;
+}
projects / oweals / busybox.git / blobdiff