Allow fsck for read-only mounted filesystems

When starting up a system booted from initramfs / may already be
mounted (read-only), so we can safely fsck it before proceeding
to remount it as read-write later (possibly).

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/finit.c

@@ -115,8 +115,8 @@ static int fsck(int pass)
 			}
 		}
 
-		if (fismnt(fs->fs_file)) {
+		if (ismnt("/proc/mounts", fs->fs_file, "rw")) {
-			_d("Skipping fsck of %s, already mounted on %s.", fs->fs_spec, fs->fs_file);
+			_d("Skipping fsck of %s, already mounted rw on %s.", fs->fs_spec, fs->fs_file);
 			continue;
 		}
 
@@ -288,8 +288,8 @@ int main(int argc, char *argv[])
 		.delay = 1000
 	};
 	uev_ctx_t loop;
-	char *path;
 	char cmd[256];
+	char *path;
 
 	/*
 	 * finit/init/telinit client tool uses /dev/initctl pipe
@@ -376,8 +376,11 @@ int main(int argc, char *argv[])
 	 * Check file filesystems in /etc/fstab
 	 */
 	for (int pass = 1; pass < 10 && !rescue; pass++) {
-		if (fsck(pass))
+		if (fsck(pass)) {
 			break;
+		}
+	}
+
 	}
 
 	/*
@@ -406,7 +409,7 @@ int main(int argc, char *argv[])
 	 * the /etc/fstab file already.
 	 */
 	makedir("/dev/shm", 0755);
-	if (!fismnt("/dev/shm") && !ismnt("/etc/fstab", "/dev/shm"))
+	if (!fismnt("/dev/shm") && !ismnt("/etc/fstab", "/dev/shm", NULL))
 		mount("shm", "/dev/shm", "tmpfs", 0, "mode=0777");
 
 	/*

src/helpers.c

@@ -429,12 +429,28 @@ void endfsent(void)
 }
 #endif	/* HAVE_GETFSENT */
 
+static int hasopt(char *opts, char *opt)
+{
+	char buf[strlen(opts) + 1];
+	char *ptr;
 
-int ismnt(char *file, char *dir)
+	memcpy(buf, opts, sizeof(buf));
+	ptr = strtok(buf, ",");
+	while (ptr) {
+		if (!strcmp(ptr, opt))
+			return 1;
+
+		ptr = strtok(NULL, ",");
+	}
+
+	return 0;
+}
+
+int ismnt(char *file, char *dir, char *mode)
 {
-	FILE *fp;
-	int found = 0;
 	struct mntent *mnt;
+	int found = 0;
+	FILE *fp;
 
 	fp = setmntent(file, "r");
 	if (!fp)
@@ -442,7 +458,10 @@ int ismnt(char *file, char *dir)
 
 	while ((mnt = getmntent(fp))) {
 		if (!strcmp(mnt->mnt_dir, dir)) {
-			found = 1;
+			if (mode && hasopt(mnt->mnt_opts, mode))
+				found = 1;
+			else
+				found = 1;
 			break;
 		}
 	}
@@ -454,7 +473,7 @@ int ismnt(char *file, char *dir)
 /* Requires /proc to be mounted */
 int fismnt(char *dir)
 {
-	return ismnt("/proc/mounts", dir);
+	return ismnt("/proc/mounts", dir, NULL);
 }
 
 /**

src/helpers.h

@@ -88,7 +88,7 @@ static inline int create(char *path, mode_t mode, uid_t uid, gid_t gid)
 	return 0;
 }
 
-int	ismnt		(char *file, char *dir);
+int	ismnt		(char *file, char *dir, char *mode);
 int	fismnt		(char *dir);
 
 #endif /* FINIT_HELPERS_H_ */