Merge "fs_mgr: make block devices read-only" (44a5fb57) · Commits · e / os / android_system_core

adb/remount_service.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -72,6 +72,8 @@ static char find_mount(const char dir)
		static int remount_system()
		{
		char *dev;
		int fd;
		int OFF = 0;

		if (system_ro == 0) {
		return 0;
		@@ -82,6 +84,13 @@ static int remount_system()
		if (!dev)
		return -1;

		fd = unix_open(dev, O_RDONLY);
		if (fd < 0)
		return -1;

		ioctl(fd, BLKROSET, &OFF);
		adb_close(fd);

		system_ro = mount(dev, "/system", "none", MS_REMOUNT, NULL);

		free(dev);

fs_mgr/fs_mgr.c

+42 −5

Original line number	Diff line number	Diff line
		@@ -487,6 +487,43 @@ static void remove_trailing_slashes(char *n)
		}
		}

		/*
		* Mark the given block device as read-only, using the BLKROSET ioctl.
		* Return 0 on success, and -1 on error.
		*/
		static void fs_set_blk_ro(const char *blockdev)
		{
		int fd;
		int ON = 1;

		fd = open(blockdev, O_RDONLY);
		if (fd < 0) {
		// should never happen
		return;
		}

		ioctl(fd, BLKROSET, &ON);
		close(fd);
		}

		/*
		* __mount(): wrapper around the mount() system call which also
		* sets the underlying block device to read-only if the mount is read-only.
		* See "man 2 mount" for return values.
		*/
		static int __mount(const char source, const char target,
		const char *filesystemtype, unsigned long mountflags,
		const void *data)
		{
		int ret = mount(source, target, filesystemtype, mountflags, data);

		if ((ret == 0) && (mountflags & MS_RDONLY) != 0) {
		fs_set_blk_ro(source);
		}

		return ret;
		}

		static int fs_match(char in1, char in2)
		{
		char *n1;
		@@ -539,7 +576,7 @@ int fs_mgr_mount_all(struct fstab *fstab)
		fstab->recs[i].mount_point);
		}

		mret = mount(fstab->recs[i].blk_device, fstab->recs[i].mount_point,
		mret = __mount(fstab->recs[i].blk_device, fstab->recs[i].mount_point,
		fstab->recs[i].fs_type, fstab->recs[i].flags,
		fstab->recs[i].fs_options);
		if (!mret) {
		@@ -621,7 +658,7 @@ int fs_mgr_do_mount(struct fstab fstab, char n_name, char *n_blk_device,
		} else {
		m = fstab->recs[i].mount_point;
		}
		if (mount(n_blk_device, m, fstab->recs[i].fs_type,
		if (__mount(n_blk_device, m, fstab->recs[i].fs_type,
		fstab->recs[i].flags, fstab->recs[i].fs_options)) {
		ERROR("Cannot mount filesystem on %s at %s\n",
		n_blk_device, m);

toolbox/mount.c

+22 −0

Original line number	Diff line number	Diff line
		@@ -138,6 +138,24 @@ parse_mount_options(char arg, unsigned long rwflag, struct extra_opts extra, i
		return rwflag;
		}

		/*
		* Mark the given block device as read-write, using the BLKROSET ioctl.
		*/
		static void fs_set_blk_rw(const char *blockdev)
		{
		int fd;
		int OFF = 0;

		fd = open(blockdev, O_RDONLY);
		if (fd < 0) {
		// should never happen
		return;
		}

		ioctl(fd, BLKROSET, &OFF);
		close(fd);
		}

		static char *progname;

		static struct extra_opts extra;
		@@ -179,6 +197,10 @@ do_mount(char dev, char dir, char type, unsigned long rwflag, void data, int
		dev = loopdev;
		}

		if ((rwflag & MS_RDONLY) == 0) {
		fs_set_blk_rw(dev);
		}

		while ((s = strsep(&type, ",")) != NULL) {
		retry:
		if (mount(dev, dir, s, rwflag, data) == -1) {