diff --git a/sbin/mount/getmntopts.c b/sbin/mount/getmntopts.c --- a/sbin/mount/getmntopts.c +++ b/sbin/mount/getmntopts.c @@ -139,6 +139,20 @@ return (0); } +int +checkpath_allow_file(const char *path, char *resolved) +{ + struct stat sb; + + if (realpath(path, resolved) == NULL || stat(resolved, &sb) != 0) + return (1); + if (!S_ISDIR(sb.st_mode) && !S_ISREG(sb.st_mode)) { + errno = ENOTDIR; + return (1); + } + return (0); +} + void build_iovec(struct iovec **iov, int *iovlen, const char *name, void *val, size_t len) diff --git a/sbin/mount/mntopts.h b/sbin/mount/mntopts.h --- a/sbin/mount/mntopts.h +++ b/sbin/mount/mntopts.h @@ -103,6 +103,7 @@ void getmntopts(const char *, const struct mntopt *, int *, int *); void rmslashes(char *, char *); int checkpath(const char *, char resolved_path[]); +int checkpath_allow_file(const char *, char resolved_path[]); extern int getmnt_silent; void build_iovec(struct iovec **iov, int *iovlen, const char *name, void *val, size_t len); void build_iovec_argf(struct iovec **iov, int *iovlen, const char *name, const char *fmt, ...); diff --git a/sbin/mount/mount.c b/sbin/mount/mount.c --- a/sbin/mount/mount.c +++ b/sbin/mount/mount.c @@ -89,6 +89,7 @@ int hasopt(const char *, const char *); int ismounted(struct fstab *, struct statfs *, int); int isremountable(const char *); +int allow_file_mount(const char *); void mangle(char *, struct cpa *); char *update_options(char *, char *, int); int mountfs(const char *, const char *, const char *, @@ -502,6 +503,15 @@ return (0); } +int +allow_file_mount(const char *vfsname) +{ + + if (strcmp(vfsname, "nullfs") == 0) + return (1); + return (0); +} + int hasopt(const char *mntopts, const char *option) { @@ -548,9 +558,16 @@ static struct cpa mnt_argv; /* resolve the mountpoint with realpath(3) */ - if (checkpath(name, mntpath) != 0) { - xo_warn("%s", mntpath); - return (1); + if (allow_file_mount(vfstype)) { + if (checkpath_allow_file(name, mntpath) != 0) { + xo_warn("%s", mntpath); + return (1); + } + } else { + if (checkpath(name, mntpath) != 0) { + xo_warn("%s", mntpath); + return (1); + } } name = mntpath; diff --git a/sbin/mount_nullfs/mount_nullfs.8 b/sbin/mount_nullfs/mount_nullfs.8 --- a/sbin/mount_nullfs/mount_nullfs.8 +++ b/sbin/mount_nullfs/mount_nullfs.8 @@ -64,6 +64,17 @@ .Pp The .Nm +utility supports mounting both directories and single files. +Both +.Ar target +and +.Ar mount_point +must be the same type. +Mounting directories to files or files to +directories is not supported. +.Pp +The +.Nm file system differs from a traditional loopback file system in two respects: it is implemented using a stackable layers techniques, and its diff --git a/sbin/mount_nullfs/mount_nullfs.c b/sbin/mount_nullfs/mount_nullfs.c --- a/sbin/mount_nullfs/mount_nullfs.c +++ b/sbin/mount_nullfs/mount_nullfs.c @@ -48,6 +48,7 @@ #include #include +#include #include #include @@ -61,6 +62,14 @@ static void usage(void) __dead2; +static int +stat_realpath(const char *path, char *resolved, struct stat *sbp) +{ + if (realpath(path, resolved) == NULL || stat(resolved, sbp) != 0) + return (1); + return (0); +} + int main(int argc, char *argv[]) { @@ -71,6 +80,8 @@ char errmsg[255]; int ch, iovlen; char nullfs[] = "nullfs"; + struct stat target_stat; + struct stat mountpoint_stat; iov = NULL; iovlen = 0; @@ -98,10 +109,18 @@ usage(); /* resolve target and mountpoint with realpath(3) */ - if (checkpath(argv[0], target) != 0) + if (stat_realpath(argv[0], target, &target_stat) != 0) err(EX_USAGE, "%s", target); - if (checkpath(argv[1], mountpoint) != 0) + if (stat_realpath(argv[1], mountpoint, &mountpoint_stat) != 0) err(EX_USAGE, "%s", mountpoint); + if (!S_ISDIR(target_stat.st_mode) && !S_ISREG(target_stat.st_mode)) + errx(EX_USAGE, "%s: must be either a file or directory", + target); + if ((target_stat.st_mode & S_IFMT) != + (mountpoint_stat.st_mode & S_IFMT)) + errx(EX_USAGE, + "%s: must be same type as %s (file or directory)", + mountpoint, target); build_iovec(&iov, &iovlen, "fstype", nullfs, (size_t)-1); build_iovec(&iov, &iovlen, "fspath", mountpoint, (size_t)-1);