[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit

Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/app/busybox/src/util-linux/umount.c b/ap/app/busybox/src/util-linux/umount.c
new file mode 100644
index 0000000..4c2e882
--- /dev/null
+++ b/ap/app/busybox/src/util-linux/umount.c
@@ -0,0 +1,206 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini umount implementation for busybox
+ *
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ * Copyright (C) 2005 by Rob Landley <rob@landley.net>
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+
+//usage:#define umount_trivial_usage
+//usage:       "[OPTIONS] FILESYSTEM|DIRECTORY"
+//usage:#define umount_full_usage "\n\n"
+//usage:       "Unmount file systems\n"
+//usage:	IF_FEATURE_UMOUNT_ALL(
+//usage:     "\n	-a	Unmount all file systems" IF_FEATURE_MTAB_SUPPORT(" in /etc/mtab")
+//usage:	)
+//usage:	IF_FEATURE_MTAB_SUPPORT(
+//usage:     "\n	-n	Don't erase /etc/mtab entries"
+//usage:	)
+//usage:     "\n	-r	Try to remount devices as read-only if mount is busy"
+//usage:     "\n	-l	Lazy umount (detach filesystem)"
+//usage:     "\n	-f	Force umount (i.e., unreachable NFS server)"
+//usage:	IF_FEATURE_MOUNT_LOOP(
+//usage:     "\n	-D	Don't free loop device even if it has been used"
+//usage:	)
+//usage:
+//usage:#define umount_example_usage
+//usage:       "$ umount /dev/hdc1\n"
+
+#include <mntent.h>
+#include <sys/mount.h>
+#include "libbb.h"
+
+#if defined(__dietlibc__)
+// TODO: This does not belong here.
+/* 16.12.2006, Sampo Kellomaki (sampo@iki.fi)
+ * dietlibc-0.30 does not have implementation of getmntent_r() */
+static struct mntent *getmntent_r(FILE* stream, struct mntent* result,
+		char* buffer UNUSED_PARAM, int bufsize UNUSED_PARAM)
+{
+	struct mntent* ment = getmntent(stream);
+	return memcpy(result, ment, sizeof(*ment));
+}
+#endif
+
+/* Ignored: -v -t -i
+ * bbox always acts as if -d is present.
+ * -D can be used to suppress it (bbox extension).
+ * Rationale:
+ * (1) util-linux's umount does it if "loop=..." is seen in /etc/mtab:
+ * thus, on many systems, bare umount _does_ drop loop devices.
+ * (2) many users request this feature.
+ */
+#define OPTION_STRING           "fldDnra" "vt:i"
+#define OPT_FORCE               (1 << 0) // Same as MNT_FORCE
+#define OPT_LAZY                (1 << 1) // Same as MNT_DETACH
+//#define OPT_FREE_LOOP           (1 << 2) // -d is assumed always present
+#define OPT_DONT_FREE_LOOP      (1 << 3)
+#define OPT_NO_MTAB             (1 << 4)
+#define OPT_REMOUNT             (1 << 5)
+#define OPT_ALL                 (ENABLE_FEATURE_UMOUNT_ALL ? (1 << 6) : 0)
+
+int umount_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int umount_main(int argc UNUSED_PARAM, char **argv)
+{
+	int doForce;
+	struct mntent me;
+	FILE *fp;
+	char *fstype = NULL;
+	int status = EXIT_SUCCESS;
+	unsigned opt;
+	struct mtab_list {
+		char *dir;
+		char *device;
+		struct mtab_list *next;
+	} *mtl, *m;
+
+	opt = getopt32(argv, OPTION_STRING, &fstype);
+	//argc -= optind;
+	argv += optind;
+
+	// MNT_FORCE and MNT_DETACH (from linux/fs.h) must match
+	// OPT_FORCE and OPT_LAZY, otherwise this trick won't work:
+	doForce = MAX((opt & OPT_FORCE), (opt & OPT_LAZY));
+
+	/* Get a list of mount points from mtab.  We read them all in now mostly
+	 * for umount -a (so we don't have to worry about the list changing while
+	 * we iterate over it, or about getting stuck in a loop on the same failing
+	 * entry.  Notice that this also naturally reverses the list so that -a
+	 * umounts the most recent entries first. */
+	m = mtl = NULL;
+
+	// If we're umounting all, then m points to the start of the list and
+	// the argument list should be empty (which will match all).
+	fp = setmntent(bb_path_mtab_file, "r");
+	if (!fp) {
+		if (opt & OPT_ALL)
+			bb_error_msg_and_die("can't open '%s'", bb_path_mtab_file);
+	} else {
+		while (getmntent_r(fp, &me, bb_common_bufsiz1, sizeof(bb_common_bufsiz1))) {
+			/* Match fstype if passed */
+			if (!match_fstype(&me, fstype))
+				continue;
+			m = xzalloc(sizeof(*m));
+			m->next = mtl;
+			m->device = xstrdup(me.mnt_fsname);
+			m->dir = xstrdup(me.mnt_dir);
+			mtl = m;
+		}
+		endmntent(fp);
+	}
+
+	// If we're not umounting all, we need at least one argument.
+	if (!(opt & OPT_ALL) && !fstype) {
+		if (!argv[0])
+			bb_show_usage();
+		m = NULL;
+	}
+
+	// Loop through everything we're supposed to umount, and do so.
+	for (;;) {
+		int curstat;
+		char *zapit = *argv;
+		char *path;
+
+		// Do we already know what to umount this time through the loop?
+		if (m)
+			path = xstrdup(m->dir);
+		// For umount -a, end of mtab means time to exit.
+		else if (opt & OPT_ALL)
+			break;
+		// Use command line argument (and look it up in mtab list)
+		else {
+			if (!zapit)
+				break;
+			argv++;
+			path = xmalloc_realpath(zapit);
+			if (path) {
+				for (m = mtl; m; m = m->next)
+					if (strcmp(path, m->dir) == 0 || strcmp(path, m->device) == 0)
+						break;
+			}
+		}
+		// If we couldn't find this sucker in /etc/mtab, punt by passing our
+		// command line argument straight to the umount syscall.  Otherwise,
+		// umount the directory even if we were given the block device.
+		if (m) zapit = m->dir;
+
+		// Let's ask the thing nicely to unmount.
+		curstat = umount(zapit);
+
+		// Force the unmount, if necessary.
+		if (curstat && doForce)
+			curstat = umount2(zapit, doForce);
+
+		// If still can't umount, maybe remount read-only?
+		if (curstat) {
+			if ((opt & OPT_REMOUNT) && errno == EBUSY && m) {
+				// Note! Even if we succeed here, later we should not
+				// free loop device or erase mtab entry!
+				const char *msg = "%s busy - remounted read-only";
+				curstat = mount(m->device, zapit, NULL, MS_REMOUNT|MS_RDONLY, NULL);
+				if (curstat) {
+					msg = "can't remount %s read-only";
+					status = EXIT_FAILURE;
+				}
+				bb_error_msg(msg, m->device);
+			} else {
+				status = EXIT_FAILURE;
+				bb_perror_msg("can't %sumount %s", (doForce ? "forcibly " : ""), zapit);
+			}
+		} else {
+			// De-allocate the loop device.  This ioctl should be ignored on
+			// any non-loop block devices.
+			if (ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONT_FREE_LOOP) && m)
+				del_loop(m->device);
+			if (ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
+				erase_mtab(m->dir);
+		}
+
+		// Find next matching mtab entry for -a or umount /dev
+		// Note this means that "umount /dev/blah" will unmount all instances
+		// of /dev/blah, not just the most recent.
+		if (m) {
+			while ((m = m->next) != NULL)
+				// NB: if m is non-NULL, path is non-NULL as well
+				if ((opt & OPT_ALL) || strcmp(path, m->device) == 0)
+					break;
+		}
+		free(path);
+	}
+
+	// Free mtab list if necessary
+	if (ENABLE_FEATURE_CLEAN_UP) {
+		while (mtl) {
+			m = mtl->next;
+			free(mtl->device);
+			free(mtl->dir);
+			free(mtl);
+			mtl = m;
+		}
+	}
+
+	return status;
+}