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authorErik Andersen2000-01-13 06:38:14 +0000
committerErik Andersen2000-01-13 06:38:14 +0000
commitb7cc49d992ed9a5a59261096012e0b4a811bb7f4 (patch)
treed151960bd89e78df235150a498cb63f39bfcab2e /util-linux
parent05df239ed90584156b820dbf3ede638208eb440f (diff)
downloadbusybox-b7cc49d992ed9a5a59261096012e0b4a811bb7f4.zip
busybox-b7cc49d992ed9a5a59261096012e0b4a811bb7f4.tar.gz
* Added -o loop option for mount, and support in umount for loop
devices. Support is toggled by MOUNT_LOOP feature -- Ben Collins <bcollins@debian.org> -Erik
Diffstat (limited to 'util-linux')
-rw-r--r--util-linux/mount.c139
-rw-r--r--util-linux/umount.c72
2 files changed, 189 insertions, 22 deletions
diff --git a/util-linux/mount.c b/util-linux/mount.c
index ee6fe15..8777a3b 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -28,7 +28,10 @@
* putting it back as a compile-time option some time),
* major adjustments to option parsing, and some serious
* dieting all around.
-*/
+ *
+ * 2000-01-12 Ben Collins <bcollins@debian.org>, Borrowed utils-linux's
+ * mount to add loop support.
+ */
#include "internal.h"
#include <stdlib.h>
@@ -41,6 +44,17 @@
#include <ctype.h>
#include <fstab.h>
+#if defined BB_FEATURE_MOUNT_LOOP
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/loop.h>
+
+static int set_loop(const char *device, const char *file, int offset, int *loopro);
+static char *find_unused_loop_device (void);
+
+static int use_loop = 0;
+#endif
+
extern const char mtab_file[]; /* Defined in utility.c */
static const char mount_usage[] = "\tmount [flags]\n"
@@ -61,6 +75,9 @@ static const char mount_usage[] = "\tmount [flags]\n"
"\tasync / sync:\tWrites are asynchronous / synchronous.\n"
"\tdev / nodev:\tAllow use of special device files / disallow them.\n"
"\texec / noexec:\tAllow use of executable files / disallow them.\n"
+#if defined BB_FEATURE_MOUNT_LOOP
+ "\tloop: Mounts a file via loop device.\n"
+#endif
"\tsuid / nosuid:\tAllow set-user-id-root programs / disallow them.\n"
"\tremount: Re-mount a currently-mounted filesystem, changing its flags.\n"
"\tro / rw: Mount for read-only / read-write.\n"
@@ -91,28 +108,48 @@ static const struct mount_options mount_options[] = {
{0, 0, 0}
};
-#if ! defined BB_MTAB
-#define do_mount(specialfile, dir, filesystemtype, flags, string_flags, useMtab, fakeIt, mtab_opts) \
- mount(specialfile, dir, filesystemtype, flags, string_flags)
-#else
static int
do_mount(char* specialfile, char* dir, char* filesystemtype,
long flags, void* string_flags, int useMtab, int fakeIt, char* mtab_opts)
{
int status=0;
+#if defined BB_MTAB
if (fakeIt==FALSE)
+#endif
+ {
+#if defined BB_FEATURE_MOUNT_LOOP
+ if (use_loop) {
+ int loro = flags & MS_RDONLY;
+ char *lofile = specialfile;
+ specialfile = find_unused_loop_device();
+ if (specialfile == NULL) {
+ fprintf(stderr, "Could not find a spare loop device\n");
+ exit(1);
+ }
+ if (set_loop (specialfile, lofile, 0, &loro)) {
+ fprintf(stderr, "Could not setup loop device\n");
+ exit(1);
+ }
+ if (!(flags & MS_RDONLY) && loro) { /* loop is ro, but wanted rw */
+ fprintf(stderr, "WARNING: loop device is read-only\n");
+ flags &= ~MS_RDONLY;
+ }
+ }
+#endif
status=mount(specialfile, dir, filesystemtype, flags, string_flags);
-
- if ( status == 0 ) {
- if ( useMtab==TRUE )
+ }
+#if defined BB_MTAB
+ if (status == 0) {
+ if (useMtab==TRUE)
write_mtab(specialfile, dir, filesystemtype, flags, mtab_opts);
return 0;
}
- else
- return( status);
-}
+ else
#endif
+ return(status);
+}
+
#if defined BB_MTAB
@@ -148,16 +185,20 @@ parse_mount_options ( char *options, unsigned long *flags, char *strflags)
}
f++;
}
+#if defined BB_FEATURE_MOUNT_LOOP
+ if (gotone==FALSE && !strcasecmp ("loop", options)) { /* loop device support */
+ use_loop = 1;
+ gotone=TRUE;
+ }
+#endif
if (*strflags && strflags!= '\0' && gotone==FALSE) {
char *temp=strflags;
temp += strlen (strflags);
*temp++ = ',';
*temp++ = '\0';
}
- if (gotone==FALSE) {
+ if (gotone==FALSE)
strcat (strflags, options);
- gotone=FALSE;
- }
if (comma) {
*comma = ',';
options = ++comma;
@@ -356,3 +397,73 @@ extern int mount_main (int argc, char **argv)
goodbye:
usage( mount_usage);
}
+
+#if defined BB_FEATURE_MOUNT_LOOP
+static 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)) {
+ perror (file);
+ return 1;
+ }
+ if ((fd = open (device, mode)) < 0) {
+ close(ffd);
+ perror (device);
+ return 1;
+ }
+ *loopro = (mode == O_RDONLY);
+
+ memset(&loopinfo, 0, sizeof(loopinfo));
+ strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
+ loopinfo.lo_name[LO_NAME_SIZE-1] = 0;
+
+ loopinfo.lo_offset = offset;
+
+ loopinfo.lo_encrypt_key_size = 0;
+ if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
+ perror("ioctl: LOOP_SET_FD");
+ exit(1);
+ }
+ if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
+ (void) ioctl(fd, LOOP_CLR_FD, 0);
+ perror("ioctl: LOOP_SET_STATUS");
+ exit(1);
+ }
+ close(fd);
+ close(ffd);
+ return 0;
+}
+
+static char *find_unused_loop_device (void)
+{
+ char dev[20];
+ int i, fd, somedev = 0, someloop = 0;
+ struct stat statbuf;
+ struct loop_info loopinfo;
+
+ for(i = 0; i < 256; i++) {
+ sprintf(dev, "/dev/loop%d", i);
+ if (stat (dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
+ somedev++;
+ fd = open (dev, O_RDONLY);
+ if (fd >= 0) {
+ if(ioctl (fd, LOOP_GET_STATUS, &loopinfo) == 0)
+ someloop++; /* in use */
+ else if (errno == ENXIO) {
+ close (fd);
+ return strdup(dev); /* probably free */
+ }
+ close (fd);
+ }
+ continue;
+ }
+ if (i >= 7)
+ break;
+ }
+ return NULL;
+}
+#endif /* BB_FEATURE_MOUNT_LOOP */
diff --git a/util-linux/umount.c b/util-linux/umount.c
index ab76be4..af1b3a4 100644
--- a/util-linux/umount.c
+++ b/util-linux/umount.c
@@ -28,6 +28,14 @@
#include <fstab.h>
#include <errno.h>
+#if defined BB_FEATURE_MOUNT_LOOP
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/loop.h>
+
+static int del_loop(const char *device);
+#endif
+
static const char umount_usage[] =
"Usage: umount [flags] filesystem|directory\n\n"
"Flags:\n"
@@ -44,23 +52,54 @@ static int useMtab = TRUE;
static int umountAll = FALSE;
extern const char mtab_file[]; /* Defined in utility.c */
-#if ! defined BB_MTAB
-#define do_umount( blockDevice, useMtab) umount( blockDevice)
-#else
static int
do_umount(const char* name, int useMtab)
{
- int status = umount(name);
+ int status;
+
+#if defined BB_FEATURE_MOUNT_LOOP
+ /* check to see if this is a loop device */
+ struct stat fst;
+ char dev[20];
+ const char *oldname = NULL;
+ int i;
+
+ if (stat(name, &fst)) {
+ fprintf(stderr, "umount: %s: %s\n", name, strerror(errno));
+ exit(1);
+ }
+ for (i = 0 ; i <= 7 ; i++) {
+ struct stat lst;
+ sprintf(dev, "/dev/loop%d", i);
+ if (stat(dev, &lst))
+ continue;
+ if (lst.st_dev == fst.st_dev) {
+ oldname = name;
+ name = dev;
+ break;
+ }
+ }
+#endif
+
+ status = umount(name);
+#if defined BB_FEATURE_MOUNT_LOOP
+ if (!strncmp("/dev/loop", name, 9)) { /* this was a loop device, delete it */
+ del_loop(name);
+ if (oldname != NULL)
+ name = oldname;
+ }
+#endif
+#if defined BB_MTAB
if ( status == 0 ) {
if ( useMtab==TRUE )
erase_mtab(name);
return 0;
}
- else
- return( status);
-}
+ else
#endif
+ return(status);
+}
static int
umount_all(int useMtab)
@@ -135,7 +174,24 @@ umount_main(int argc, char** argv)
exit (TRUE);
else {
perror("umount");
- exit( FALSE);
+ exit(FALSE);
}
}
+#if defined BB_FEATURE_MOUNT_LOOP
+static int del_loop(const char *device)
+{
+ int fd;
+
+ if ((fd = open(device, O_RDONLY)) < 0) {
+ perror(device);
+ exit(1);
+ }
+ if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
+ perror("ioctl: LOOP_CLR_FD");
+ exit(1);
+ }
+ close(fd);
+ return(0);
+}
+#endif