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Diffstat (limited to 'i/pc104/initrd/conf/busybox/libbb/loop.c')
-rw-r--r--i/pc104/initrd/conf/busybox/libbb/loop.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/i/pc104/initrd/conf/busybox/libbb/loop.c b/i/pc104/initrd/conf/busybox/libbb/loop.c
new file mode 100644
index 0000000..9818a30
--- /dev/null
+++ b/i/pc104/initrd/conf/busybox/libbb/loop.c
@@ -0,0 +1,149 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * 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.
+ */
+
+#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>
+typedef struct loop_info64 bb_loop_info;
+#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
+typedef struct {
+ int lo_number;
+ __kernel_dev_t lo_device;
+ unsigned long lo_inode;
+ __kernel_dev_t lo_rdevice;
+ int lo_offset;
+ int lo_encrypt_type;
+ int lo_encrypt_key_size;
+ int lo_flags;
+ 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
+
+char *query_loop(const char *device)
+{
+ int fd;
+ bb_loop_info loopinfo;
+ char *dev = 0;
+
+ fd = open(device, O_RDONLY);
+ if (fd < 0) return 0;
+ if (!ioctl(fd, BB_LOOP_GET_STATUS, &loopinfo))
+ dev = xasprintf("%ld %s", (long) loopinfo.lo_offset,
+ (char *)loopinfo.lo_file_name);
+ close(fd);
+
+ return dev;
+}
+
+
+int del_loop(const char *device)
+{
+ int fd, rc;
+
+ fd = open(device, O_RDONLY);
+ if (fd < 0) return 1;
+ rc = ioctl(fd, LOOP_CLR_FD, 0);
+ close(fd);
+
+ return rc;
+}
+
+/* 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, unsigned long long offset)
+{
+ char dev[20], *try;
+ bb_loop_info loopinfo;
+ struct stat statbuf;
+ int i, dfd, ffd, mode, rc=-1;
+
+ /* Open the file. Barf if this doesn't work. */
+ 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++) {
+ sprintf(dev, LOOP_FORMAT, i);
+
+ /* Ran out of block devices, return failure. */
+ if (stat(try, &statbuf) || !S_ISBLK(statbuf.st_mode)) {
+ rc=-ENOENT;
+ break;
+ }
+ /* Open the sucker and check its loopiness. */
+ 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);
+
+ /* 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)) {
+ if (!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 = xstrdup(dev);
+ return mode==O_RDONLY ? 1 : 0;
+ }
+ return rc;
+}