libmount: split context.c

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 73 insertions, 833 deletions

diff --git a/shlibs/mount/src/context.c b/shlibs/mount/src/context.c
index 2102be539..07a72c2d3 100644
--- a/shlibs/mount/src/context.c
+++ b/shlibs/mount/src/context.c
@@ -13,87 +13,9 @@
 #include <string.h>
 #include <errno.h>
 
-#include <sys/wait.h>
-#include <sys/mount.h>
-
-#ifdef HAVE_LIBSELINUX
-#include <selinux/selinux.h>
-#include <selinux/context.h>
-#endif
-
 #include "c.h"
 #include "mountP.h"
 
-/*
- * Mount context -- high-level API
- */
-struct _mnt_context
-{
-	int	action;		/* MNT_ACT_{MOUNT,UMOUNT} */
-
-	int	restricted;	/* root or not? */
-
-	char	*fstype_pattern;	/* for mnt_match_fstype() */
-	char	*optstr_pattern;	/* for mnt_match_options() */
-
-	char	*spec;		/* unresolved source OR target */
-	mnt_fs	*fs;		/* filesystem description (type, mountpopint, device, ...) */
-
-	mnt_tab	*fstab;		/* fstab (or mtab for some remounts) entires */
-	mnt_tab *mtab;		/* mtab entries */
-	int	optsmode;	/* fstab optstr mode MNT_OPTSMODE_{AUTO,FORCE,IGNORE} */
-
-	unsigned long	mountflags;	/* final mount(2) flags */
-	const void	*mountdata;	/* final mount(2) data, string or binary data */
-
-	unsigned long	user_mountflags;	/* MNT_MS_* (loop=, user=, ...) */
-
-	mnt_update	*update;	/* mtab update */
-	mnt_cache	*cache;		/* paths cache */
-
-	int	flags;		/* private context flags */
-	int	ambi;		/* libblkid returns ambivalent result */
-
-	char	*helper;	/* name of the used /sbin/[u]mount.<type> helper */
-	int	helper_status;	/* helper wait(2) status */
-
-	char	*orig_user;	/* original (non-fixed) user= option */
-
-	int	syscall_errno;	/* mount(2) or umount(2) error */
-};
-
-/* flags */
-#define MNT_FL_NOMTAB		(1 << 1)
-#define MNT_FL_FAKE		(1 << 2)
-#define MNT_FL_SLOPPY		(1 << 3)
-#define MNT_FL_VERBOSE		(1 << 4)
-#define MNT_FL_NOHELPERS	(1 << 5)
-#define MNT_FL_LOOPDEL		(1 << 6)
-#define MNT_FL_LAZY		(1 << 7)
-#define MNT_FL_FORCE		(1 << 8)
-#define MNT_FL_NOCANONICALIZE	(1 << 9)
-#define MNT_FL_NOLOCK		(1 << 10)	/* don't lock mtab file */
-
-#define MNT_FL_EXTERN_FS	(1 << 15)	/* cxt->fs is not private */
-#define MNT_FL_EXTERN_FSTAB	(1 << 16)	/* cxt->fstab is not private */
-#define MNT_FL_EXTERN_CACHE	(1 << 17)	/* cxt->cache is not private */
-
-#define MNT_FL_MOUNTDATA	(1 << 20)
-#define MNT_FL_FSTAB_APPLIED	(1 << 21)
-#define MNT_FL_MOUNTFLAGS_MERGED (1 << 22)	/* MS_* flags was read from optstr */
-#define MNT_FL_SAVED_USER	(1 << 23)
-
-/* default flags */
-#define MNT_FL_DEFAULT		0
-
-/* mode for mount options from fstab */
-enum {
-	MNT_OPTSMODE_AUTO = 0,		/* use options if source or target are not defined */
-	MNT_OPTSMODE_IGNORE,		/* never use mount options from fstab */
-	MNT_OPTSMODE_FORCE,		/* always use mount options from fstab */
-	MNT_OPTSMODE_MTABFORCE,		/* for MS_REMOUNT use always options mountinfo/mtab */
-};
-
 /**
  * mnt_new_context:
  *
@@ -212,7 +134,7 @@ int mnt_reset_context(mnt_context *cxt)
 	return 0;
 }
 
-static int mnt_context_set_flag(mnt_context *cxt, int flag, int enable)
+static int set_flag(mnt_context *cxt, int flag, int enable)
 {
 	if (!cxt)
 		return -EINVAL;
@@ -223,17 +145,6 @@ static int mnt_context_set_flag(mnt_context *cxt, int flag, int enable)
 	return 0;
 }
 
-static mnt_fs *mnt_context_get_fs(mnt_context *cxt)
-{
-	if (!cxt)
-		return NULL;
-	if (!cxt->fs) {
-		cxt->fs = mnt_new_fs();
-		cxt->flags &= ~MNT_FL_EXTERN_FS;
-	}
-	return cxt->fs;
-}
-
 /**
  * mnt_context_is_restricted:
  * @cxt: mount context
@@ -292,7 +203,7 @@ int mnt_context_set_optsmode(mnt_context *cxt, int mode)
  */
 int mnt_context_disable_canonicalize(mnt_context *cxt, int disable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_NOCANONICALIZE, disable);
+	return set_flag(cxt, MNT_FL_NOCANONICALIZE, disable);
 }
 
 /**
@@ -306,7 +217,7 @@ int mnt_context_disable_canonicalize(mnt_context *cxt, int disable)
  */
 int mnt_context_enable_lazy(mnt_context *cxt, int enable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_LAZY, enable);
+	return set_flag(cxt, MNT_FL_LAZY, enable);
 }
 
 /**
@@ -320,7 +231,7 @@ int mnt_context_enable_lazy(mnt_context *cxt, int enable)
  */
 int mnt_context_disable_helpers(mnt_context *cxt, int disable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_NOHELPERS, disable);
+	return set_flag(cxt, MNT_FL_NOHELPERS, disable);
 }
 
 /**
@@ -334,7 +245,7 @@ int mnt_context_disable_helpers(mnt_context *cxt, int disable)
  */
 int mnt_context_enable_sloppy(mnt_context *cxt, int enable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_SLOPPY, enable);
+	return set_flag(cxt, MNT_FL_SLOPPY, enable);
 }
 
 /**
@@ -348,7 +259,7 @@ int mnt_context_enable_sloppy(mnt_context *cxt, int enable)
  */
 int mnt_context_enable_fake(mnt_context *cxt, int enable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_FAKE, enable);
+	return set_flag(cxt, MNT_FL_FAKE, enable);
 }
 
 /**
@@ -362,7 +273,7 @@ int mnt_context_enable_fake(mnt_context *cxt, int enable)
  */
 int mnt_context_disable_mtab(mnt_context *cxt, int disable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_NOMTAB, disable);
+	return set_flag(cxt, MNT_FL_NOMTAB, disable);
 }
 
 /**
@@ -376,7 +287,7 @@ int mnt_context_disable_mtab(mnt_context *cxt, int disable)
  */
 int mnt_context_disable_lock(mnt_context *cxt, int disable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_NOLOCK, disable);
+	return set_flag(cxt, MNT_FL_NOLOCK, disable);
 }
 
 /**
@@ -390,7 +301,7 @@ int mnt_context_disable_lock(mnt_context *cxt, int disable)
  */
 int mnt_context_enable_force(mnt_context *cxt, int enable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_FORCE, enable);
+	return set_flag(cxt, MNT_FL_FORCE, enable);
 }
 
 /**
@@ -398,13 +309,13 @@ int mnt_context_enable_force(mnt_context *cxt, int enable)
  * @cxt: mount context
  * @enable: TRUE or FALSE
  *
- * Enable/disable verbose output.
+ * Enable/disable verbose output (see also mnt_context_mount_strerror()).
  *
  * Returns: 0 on success, negative number in case of error.
  */
 int mnt_context_enable_verbose(mnt_context *cxt, int enable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_VERBOSE, enable);
+	return set_flag(cxt, MNT_FL_VERBOSE, enable);
 }
 
 /**
@@ -418,7 +329,7 @@ int mnt_context_enable_verbose(mnt_context *cxt, int enable)
  */
 int mnt_context_enable_loopdel(mnt_context *cxt, int enable)
 {
-	return mnt_context_set_flag(cxt, MNT_FL_LOOPDEL, enable);
+	return set_flag(cxt, MNT_FL_LOOPDEL, enable);
 }
 
 /**
@@ -464,11 +375,22 @@ int mnt_context_set_fs(mnt_context *cxt, mnt_fs *fs)
 	if (!(cxt->flags & MNT_FL_EXTERN_FS))
 		mnt_free_fs(cxt->fs);
 
-	mnt_context_set_flag(cxt, MNT_FL_EXTERN_FS, fs != NULL);
+	set_flag(cxt, MNT_FL_EXTERN_FS, fs != NULL);
 	cxt->fs = fs;
 	return 0;
 }
 
+mnt_fs *mnt_context_get_fs(mnt_context *cxt)
+{
+	if (!cxt)
+		return NULL;
+	if (!cxt->fs) {
+		cxt->fs = mnt_new_fs();
+		cxt->flags &= ~MNT_FL_EXTERN_FS;
+	}
+	return cxt->fs;
+}
+
 /**
  * mnt_context_set_source:
  * @cxt: mount context
@@ -606,7 +528,7 @@ int mnt_context_set_fstab(mnt_context *cxt, mnt_tab *tb)
 	if (!(cxt->flags & MNT_FL_EXTERN_FSTAB))
 		mnt_free_tab(cxt->fstab);
 
-	mnt_context_set_flag(cxt, MNT_FL_EXTERN_FSTAB, tb != NULL);
+	set_flag(cxt, MNT_FL_EXTERN_FSTAB, tb != NULL);
 	cxt->fstab = tb;
 	return 0;
 }
@@ -632,12 +554,20 @@ int mnt_context_set_cache(mnt_context *cxt, mnt_cache *cache)
 	if (!(cxt->flags & MNT_FL_EXTERN_CACHE))
 		mnt_free_cache(cxt->cache);
 
-	mnt_context_set_flag(cxt, MNT_FL_EXTERN_CACHE, cache != NULL);
+	set_flag(cxt, MNT_FL_EXTERN_CACHE, cache != NULL);
 	cxt->cache = cache;
 	return 0;
 }
 
-static mnt_cache *mnt_context_get_cache(mnt_context *cxt)
+/**
+ * mnt_context_get_cache
+ * @cxt: mount context
+ *
+ * See also mnt_context_set_cache().
+ *
+ * Returns: pointer to cache or NULL if canonicalization is disabled.
+ */
+mnt_cache *mnt_context_get_cache(mnt_context *cxt)
 {
 	if (!cxt || (cxt->flags & MNT_FL_NOCANONICALIZE))
 		return NULL;
@@ -652,6 +582,33 @@ static mnt_cache *mnt_context_get_cache(mnt_context *cxt)
 }
 
 /**
+ * mnt_context_get_lock:
+ * @cxt: mount context
+ *
+ * The lock is available after mnt_context_prepare_mount() or
+ * mnt_context_prepare_umount().
+ *
+ * The application that uses libmount context does not have to care about
+ * mtab locking, but with a small exceptions: the application has to be able to
+ * remove the lock file when interrupted by signal. It means that properly written
+ * mount(8)-like application has to call mnt_unlock_file() from a signal handler.
+ *
+ * See also mnt_unlock_file(), mnt_context_disable_lock() and
+ * mnt_context_disable_mtab().
+ *
+ * It's not error if this function returns NULL (it usually means that the
+ * context is not prepared yet, or mtab update is unnecessary).
+ *
+ * Returns: pointer to lock struct.
+ */
+mnt_lock *mnt_context_get_lock(mnt_context *cxt)
+{
+	if (!cxt || !cxt->update || (cxt->flags & (MNT_FL_NOMTAB | MNT_FL_NOLOCK)))
+		return NULL;
+	return mnt_update_get_lock(cxt->update);
+}
+
+/**
  * mnt_context_set_mountflags:
  * @cxt: mount context
  * @flags: mount(2) flags (MS_* flags)
@@ -704,17 +661,6 @@ int mnt_context_get_mountflags(mnt_context *cxt, unsigned long *flags)
 	return rc;
 }
 
-static int mnt_context_is_remount(mnt_context *cxt)
-{
-	unsigned long fl = 0;
-
-	if (cxt->mountflags & MS_REMOUNT)
-		return 1;
-	if (!mnt_context_get_mountflags(cxt, &fl) && (fl & MS_REMOUNT))
-		return 1;
-	return 0;
-}
-
 /**
  * mnt_context_set_userspace_mountflags:
  * @cxt: mount context
@@ -759,7 +705,7 @@ int mnt_context_get_userspace_mountflags(mnt_context *cxt, unsigned long *flags)
 	return rc;
 }
 
-static int mnt_context_is_loop(mnt_context *cxt)
+static int is_loop(mnt_context *cxt)
 {
 	unsigned long fl = 0;
 
@@ -774,7 +720,6 @@ static int mnt_context_is_loop(mnt_context *cxt)
 	return 0;
 }
 
-
 /**
  * mnt_context_set_mountdata:
  * @cxt: mount context
@@ -798,322 +743,10 @@ int mnt_context_set_mountdata(mnt_context *cxt, void *data)
 	return 0;
 }
 
-static int mnt_context_apply_tab(mnt_context *cxt, mnt_tab *tb)
-{
-	mnt_fs *fs = NULL;
-	const char *src = NULL, *tgt = NULL;
-	int rc;
-
-	if (!cxt->fs)
-		return -EINVAL;
-
-	src = mnt_fs_get_source(cxt->fs);
-	tgt = mnt_fs_get_target(cxt->fs);
-
-	if (tgt && src)
-		;	/* TODO: search pair for MNT_OPTSMODE_FORCE */
-	else if (src)
-		fs = mnt_tab_find_source(tb, src, MNT_ITER_FORWARD);
-	else if (tgt)
-		fs = mnt_tab_find_target(tb, tgt, MNT_ITER_FORWARD);
-	else if (cxt->spec) {
-		fs = mnt_tab_find_source(tb, cxt->spec, MNT_ITER_FORWARD);
-
-		if (!fs && (strncmp(cxt->spec, "LABEL=", 6) ||
-			    strncmp(cxt->spec, "UUID=", 5)))
-			fs = mnt_tab_find_target(tb, cxt->spec, MNT_ITER_FORWARD);
-	}
-
-	if (!fs)
-		return -EINVAL;
-
-	DBG(CXT, mnt_debug_h(cxt, "apply entry:"));
-	DBG(CXT, mnt_fs_print_debug(fs, stderr));
-
-	/* copy from fstab to our FS description
-	 */
-	rc = mnt_fs_set_source(cxt->fs, mnt_fs_get_source(fs));
-	if (!rc)
-		rc = mnt_fs_set_target(cxt->fs, mnt_fs_get_target(fs));
-
-	if (!rc && !mnt_fs_get_fstype(cxt->fs))
-		rc = mnt_fs_set_fstype(cxt->fs, mnt_fs_get_fstype(fs));
-
-	if (!rc && cxt->optsmode != MNT_OPTSMODE_IGNORE)
-		rc = mnt_fs_prepend_optstr(cxt->fs, mnt_fs_get_optstr(fs));
-
-	if (!rc)
-		cxt->flags |= MNT_FL_FSTAB_APPLIED;
-
-	return rc;
-}
-
-int mnt_context_apply_fstab(mnt_context *cxt)
-{
-	int rc;
-	mnt_cache *cache;
-	const char *src = NULL, *tgt = NULL;
-
-	if (!cxt || (!cxt->spec && !cxt->fs))
-		return -EINVAL;
-
-	if (cxt->flags & MNT_FL_FSTAB_APPLIED)
-		return 0;
-
-	if (cxt->fs) {
-		src = mnt_fs_get_source(cxt->fs);
-		tgt = mnt_fs_get_target(cxt->fs);
-	}
-
-	/* fstab is not required if source and target are specified */
-	if (src && tgt && !(cxt->optsmode == MNT_OPTSMODE_FORCE ||
-			    cxt->optsmode == MNT_OPTSMODE_MTABFORCE))
-		return 0;
-
-	DBG(CXT, mnt_debug_h(cxt,
-		"trying to apply fstab (src=%s, target=%s, spec=%s)",
-		src, tgt, cxt->spec));
-
-	/* initialize fstab */
-	if (!cxt->fstab) {
-		cxt->fstab = mnt_new_tab();
-		if (!cxt->fstab)
-			goto errnomem;
-		cxt->flags &= ~MNT_FL_EXTERN_FSTAB;
-		rc = mnt_tab_parse_fstab(cxt->fstab);
-		if (rc)
-			goto err;
-	}
-
-	cache = mnt_context_get_cache(cxt);	/* NULL if MNT_FL_NOCANONICALIZE is enabled */
-
-	/*  never touch an external fstab */
-	if (!(cxt->flags & MNT_FL_EXTERN_FSTAB))
-		mnt_tab_set_cache(cxt->fstab, cache);
-
-	/* let's initialize cxt->fs */
-	mnt_context_get_fs(cxt);
-
-	/* try fstab */
-	rc = mnt_context_apply_tab(cxt, cxt->fstab);
-
-	/* try mtab */
-	if (rc || (cxt->optsmode == MNT_OPTSMODE_MTABFORCE &&
-		   mnt_context_is_remount(cxt))) {
-
-		cxt->mtab = mnt_new_tab();
-		if (!cxt->mtab)
-			goto errnomem;
-		rc = mnt_tab_parse_mtab(cxt->mtab);
-		if (rc)
-			goto err;
-
-		mnt_tab_set_cache(cxt->mtab, cache);
-		rc = mnt_context_apply_tab(cxt, cxt->mtab);
-		if (rc)
-			goto err;
-	}
-	return 0;
-
-errnomem:
-	rc = ENOMEM;
-err:
-	DBG(CXT, mnt_debug_h(cxt, "failed to found entry in fstab/mtab"));
-	return rc;
-}
-
-/*
- * this has to be called after mnt_context_evaluate_permissions()
- */
-static int mnt_context_fix_optstr(mnt_context *cxt)
-{
-	int rc = 0, rem_se = 0;
-	char *next, **optstr;
-	char *name, *val;
-	size_t namesz, valsz;
-
-	if (!cxt)
-		return -EINVAL;
-	if (!cxt->fs)
-		return 0;
-
-	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
-
-	/*
-	 * we directly work with optstr pointer here
-	 */
-	optstr = &cxt->fs->optstr;
-	if (!optstr)
-		return 0;
-
-	/* The propagation flags should not be used together with any other flags */
-	if (cxt->mountflags & MS_PROPAGATION)
-		cxt->mountflags &= MS_PROPAGATION;
-
-	if (!mnt_optstr_get_option(*optstr, "user", &val, &valsz)) {
-		if (val) {
-			cxt->orig_user = strndup(val, valsz);
-			if (!cxt->orig_user) {
-				rc = -ENOMEM;
-				goto done;
-			}
-		}
-		cxt->flags |= MNT_FL_SAVED_USER;
-	}
-
-	/*
-	 * Sync mount options with mount flags
-	 */
-	rc = mnt_optstr_apply_flags(optstr, cxt->mountflags,
-				mnt_get_builtin_optmap(MNT_LINUX_MAP));
-	if (rc)
-		goto done;
-
-	rc = mnt_optstr_apply_flags(optstr, cxt->user_mountflags,
-				mnt_get_builtin_optmap(MNT_USERSPACE_MAP));
-	if (rc)
-		goto done;
-
-	next = *optstr;
-
-#ifdef HAVE_LIBSELINUX
-	rem_se = (cxt->mountflags & MS_REMOUNT) || !is_selinux_enabled();
-#endif
-	DBG(CXT, mnt_debug_h(cxt, "fixing mount options: '%s'", *optstr));
-
-	while (!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
-
-		if (namesz == 3 && !strncmp(name, "uid", 3))
-			rc = mnt_optstr_fix_uid(optstr, val, valsz, &next);
-		else if (namesz == 3 && !strncmp(name, "gid", 3))
-			rc = mnt_optstr_fix_gid(optstr, val, valsz, &next);
-#ifdef HAVE_LIBSELINUX
-		else if (namesz >= 7 && (!strncmp(name, "context", 7) ||
-					 !strncmp(name, "fscontext", 9) ||
-					 !strncmp(name, "defcontext", 10) ||
-					 !strncmp(name, "rootcontext", 11))) {
-			if (rem_se) {
-				/* remove context= option */
-				next = name;
-				rc = mnt_optstr_remove_option_at(optstr,
-							name, val + valsz);
-			} else
-				rc = mnt_optstr_fix_secontext(optstr,
-							val, valsz, &next);
-		}
-#endif
-		else if (namesz == 4 && (cxt->user_mountflags && MNT_MS_USER) &&
-			 !strncmp(name, "user", 4)) {
-
-			rc = mnt_optstr_fix_user(optstr,
-						 val ? val : name + namesz,
-						 valsz, &next);
-		}
-		if (rc)
-			goto done;
-	}
-
-done:
-	__mnt_fs_set_optstr_ptr(cxt->fs, *optstr, TRUE);
-	DBG(CXT, mnt_debug_h(cxt, "fixed options [rc=%d]: '%s'", rc, *optstr));
-	return rc;
-}
-
-/*
- * Converts already evalulated and fixed options to the form that is comaptible
- * with /sbin/mount.<type> helpers.
- *
- * Retursn newly allocated string.
- */
-static int mnt_context_get_helper_optstr(mnt_context *cxt, char **optstr)
-{
-	const char *o;
-	int rc = 0;
-
-	assert(cxt);
-	assert(cxt->fs);
-	assert(optstr);
-
-	*optstr = NULL;
-	o = mnt_fs_get_optstr(cxt->fs);
-
-	if (o)
-		rc = mnt_optstr_append_option(optstr, o, NULL);
-	if (!rc && (cxt->flags & MNT_FL_SAVED_USER))
-		rc = mnt_optstr_set_option(optstr, "user", cxt->orig_user);
-	if (rc) {
-		free(*optstr);
-		*optstr = NULL;
-	}
-	return rc;
-}
-
-
 /*
- * this has to be called before mnt_context_fix_optstr()
+ * Translates LABEL/UUID/path to mountable path
  */
-static int mnt_context_evaluate_permissions(mnt_context *cxt)
-{
-	unsigned long u_flags;
-	const char *srcpath;
-
-	if (!cxt)
-		return -EINVAL;
-	if (!cxt->fs)
-		return 0;
-
-	mnt_context_get_userspace_mountflags(cxt, &u_flags);
-
-	if (!mnt_context_is_restricted(cxt)) {
-		/*
-		 * superuser mount
-		 */
-		cxt->user_mountflags &= ~MNT_MS_OWNER;
-		cxt->user_mountflags &= ~MNT_MS_GROUP;
-		cxt->user_mountflags &= ~MNT_MS_USER;
-		cxt->user_mountflags &= ~MNT_MS_USERS;
-	} else {
-		/*
-		 * user mount
-		 */
-		if (u_flags & (MNT_MS_OWNER | MNT_MS_GROUP))
-			cxt->mountflags |= MS_OWNERSECURE;
-
-		if (u_flags & (MNT_MS_USER | MNT_MS_USERS))
-			cxt->mountflags |= MS_SECURE;
-
-		srcpath = mnt_fs_get_srcpath(cxt->fs);
-		if (!srcpath)
-			return -EINVAL;
-
-		/*
-		 * MS_OWNER: Allow owners to mount when fstab contains the
-		 * owner option.  Note that this should never be used in a high
-		 * security environment, but may be useful to give people at
-		 * the console the possibility of mounting a floppy.  MS_GROUP:
-		 * Allow members of device group to mount. (Martin Dickopp)
-		 */
-		if (u_flags & (MNT_MS_OWNER | MNT_MS_GROUP)) {
-			struct stat sb;
-
-			if (strncmp(srcpath, "/dev/", 5) == 0 &&
-			    stat(srcpath, &sb) == 0 &&
-			    (((u_flags & MNT_MS_OWNER) && getuid() == sb.st_uid) ||
-			     ((u_flags & MNT_MS_GROUP) && mnt_in_group(sb.st_gid))))
-
-				cxt->user_mountflags |= MNT_MS_USER;
-		}
-
-		if (!(cxt->user_mountflags & (MNT_MS_USER | MNT_MS_USERS))) {
-			DBG(CXT, mnt_debug_h(cxt, "permissions evaluation ends with -EPERMS"));
-			return -EPERM;
-		}
-	}
-
-	return 0;
-}
-
-static int mnt_context_prepare_srcpath(mnt_context *cxt)
+int mnt_context_prepare_srcpath(mnt_context *cxt)
 {
 	const char *path = NULL, *type;
 	mnt_cache *cache;
@@ -1168,7 +801,7 @@ static int mnt_context_prepare_srcpath(mnt_context *cxt)
 	/*
 	 * Initialize loop device
 	 */
-	if (mnt_context_is_loop(cxt) &&
+	if (is_loop(cxt) &&
 	    !(cxt->mountflags & (MS_BIND | MS_MOVE |
 			         MS_PROPAGATION | MS_REMOUNT))) {
 		; /* TODO */
@@ -1178,7 +811,7 @@ static int mnt_context_prepare_srcpath(mnt_context *cxt)
 	return 0;
 }
 
-static int mnt_context_guess_fstype(mnt_context *cxt)
+int mnt_context_guess_fstype(mnt_context *cxt)
 {
 	char *type;
 	const char *dev;
@@ -1232,26 +865,6 @@ err:
 	return rc;
 }
 
-static int mnt_context_merge_mountflags(mnt_context *cxt)
-{
-	unsigned long fl = 0;
-	int rc;
-
-	rc = mnt_context_get_mountflags(cxt, &fl);
-	if (rc)
-		return rc;
-	cxt->mountflags = fl;
-
-	fl = 0;
-	rc = mnt_context_get_userspace_mountflags(cxt, &fl);
-	if (rc)
-		return rc;
-	cxt->user_mountflags = fl;
-
-	cxt->flags |= MNT_FL_MOUNTFLAGS_MERGED;
-	return 0;
-}
-
 /*
  * The default is to use fstype from cxt->fs, this could be overwritten by
  * @type. The @act is MNT_ACT_{MOUNT,UMOUNT}.
@@ -1259,17 +872,15 @@ static int mnt_context_merge_mountflags(mnt_context *cxt)
  * Returns: 0 on success or negative number in case of error. Note that success
  * does not mean that there is any usable helper, you have to check cxt->helper.
  */
-static int mnt_context_prepare_helper(mnt_context *cxt, int act, const char *type)
+int mnt_context_prepare_helper(mnt_context *cxt, const char *name,
+				const char *type)
 {
 	char search_path[] = FS_SEARCH_PATH;		/* from config.h */
 	char *p = NULL, *path;
-	const char *name;
 
 	assert(cxt);
 	assert(cxt->fs);
 
-	name = MNT_ACT_MOUNT ? "mount" : "umount";
-
 	if (!type)
 		type = mnt_fs_get_fstype(cxt->fs);
 
@@ -1313,7 +924,10 @@ static int mnt_context_prepare_helper(mnt_context *cxt, int act, const char *typ
 	return 0;
 }
 
-static int mnt_context_prepare_update(mnt_context *cxt, int act)
+/*
+ * Prepare /etc/mtab or /var/run/mount/mountinfo update
+ */
+int mnt_context_prepare_update(mnt_context *cxt, int act)
 {
 	int rc;
 
@@ -1346,377 +960,3 @@ static int mnt_context_prepare_update(mnt_context *cxt, int act)
 	return rc;
 }
 
-/**
- * mnt_context_get_lock:
- * @cxt: mount context
- *
- * The lock is available after mnt_context_prepare_mount() or
- * mnt_context_prepare_umount().
- *
- * The application that uses libmount context does not have to care about
- * mtab locking, but with a small exceptions: the application has to be able to
- * remove the lock file when interrupted by signal. It means that properly written
- * mount(8)-like application has to call mnt_unlock_file() from a signal handler.
- *
- * See also mnt_unlock_file(), mnt_context_disable_lock() and
- * mnt_context_disable_mtab().
- *
- * It's not error if this function returns NULL (it usually means that the
- * context is not prepared yet, or mtab update is unnecessary).
- *
- * Returns: pointer to lock struct.
- */
-mnt_lock *mnt_context_get_lock(mnt_context *cxt)
-{
-	if (!cxt || !cxt->update || (cxt->flags & (MNT_FL_NOMTAB | MNT_FL_NOLOCK)))
-		return NULL;
-	return mnt_update_get_lock(cxt->update);
-}
-
-/**
- * mnt_context_prepare_mount:
- * @cxt: mount context
- *
- * This function:
- *	- read information from fstab (if necessary)
- *	- cleanup mount options
- *	- check premissions
- *	- prepare device (e.g. loop device)
- *	- detect FS type (if necessary)
- *	- generate mount flags and mount data (if not set yet)
- *	- prepare for mtab update (if necessary)
- *
- * It's strongly recommended to use this function before mnt_context_mount_fs().
- *
- * Returns: 0 on success, and negative number in case of error.
- */
-int mnt_context_prepare_mount(mnt_context *cxt)
-{
-	int rc = 0;
-
-	if (!cxt)
-		return -EINVAL;
-
-	if (!cxt->spec && !(cxt->fs && (mnt_fs_get_source(cxt->fs) ||
-			                mnt_fs_get_target(cxt->fs))))
-		return -EINVAL;
-
-	rc = mnt_context_apply_fstab(cxt);
-	if (!rc)
-		rc = mnt_context_merge_mountflags(cxt);
-	if (!rc)
-		rc = mnt_context_evaluate_permissions(cxt);
-	if (!rc)
-		rc = mnt_context_fix_optstr(cxt);
-	if (!rc)
-		rc = mnt_context_prepare_srcpath(cxt);
-	if (!rc)
-		rc = mnt_context_guess_fstype(cxt);
-	if (!rc)
-		rc = mnt_context_prepare_helper(cxt, MNT_ACT_MOUNT, NULL);
-	if (!rc)
-		rc = mnt_context_prepare_update(cxt, MNT_ACT_MOUNT);
-
-	if (!rc) {
-		DBG(CXT, mnt_debug_h(cxt, "sucessfully prepared"));
-		return 0;
-	}
-
-	DBG(CXT, mnt_debug_h(cxt, "prepare failed"));
-	return rc;
-}
-
-static int exec_mount_helper(mnt_context *cxt)
-{
-	char *o = NULL;
-	int rc;
-
-	assert(cxt);
-	assert(cxt->fs);
-	assert(cxt->helper);
-
-	rc = mnt_context_get_helper_optstr(cxt, &o);
-	if (rc)
-		goto done;
-
-	DBG_FLUSH;
-
-	switch (fork()) {
-	case 0:
-	{
-		const char *args[12], *type;
-		int i = 0;
-
-		if (setgid(getgid()) < 0)
-			exit(EXIT_FAILURE);
-
-		if (setuid(getuid()) < 0)
-			exit(EXIT_FAILURE);
-
-		type = mnt_fs_get_fstype(cxt->fs);
-
-		args[i++] = cxt->helper;			/* 1 */
-		args[i++] = mnt_fs_get_srcpath(cxt->fs);	/* 2 */
-		args[i++] = mnt_fs_get_target(cxt->fs);	/* 3 */
-
-		if (cxt->flags & MNT_FL_SLOPPY)
-			args[i++] = "-s";		/* 4 */
-		if (cxt->flags & MNT_FL_FAKE)
-			args[i++] = "-f";		/* 5 */
-		if (cxt->flags & MNT_FL_NOMTAB)
-			args[i++] = "-n";		/* 6 */
-		if (cxt->flags & MNT_FL_VERBOSE)
-			args[i++] = "-v";		/* 7 */
-		if (o) {
-			args[i++] = "-o";		/* 8 */
-			args[i++] = o;			/* 9 */
-		}
-		if (type && !endswith(cxt->helper, type)) {
-			args[i++] = "-t";		/* 10 */
-			args[i++] = type;		/* 11 */
-		}
-		args[i] = NULL;				/* 12 */
-#ifdef CONFIG_LIBMOUNT_DEBUG
-		i = 0;
-		for (i = 0; args[i]; i++)
-			DBG(CXT, mnt_debug_h(cxt, "argv[%d] = \"%s\"",
-							i, args[i]));
-#endif
-		DBG_FLUSH;
-		execv(cxt->helper, (char * const *) args);
-		exit(EXIT_FAILURE);
-	}
-	default:
-	{
-		int st;
-		wait(&st);
-		cxt->helper_status = WIFEXITED(st) ? WEXITSTATUS(st) : -1;
-
-		DBG(CXT, mnt_debug_h(cxt, "%s executed [status=%d]",
-					cxt->helper, cxt->helper_status));
-		rc = 0;
-		break;
-	}
-
-	case -1:
-		rc = -errno;
-		DBG(CXT, mnt_debug_h(cxt, "fork() failed"));
-		break;
-	}
-
-done:
-	free(o);
-	return rc;
-}
-
-/*
- * The default is to use fstype from cxt->fs, this could be overwritten by
- * @try_type argument.
- */
-static int mnt_context_do_mount(mnt_context *cxt, const char *try_type)
-{
-	int rc;
-	const char *src, *target, *type;
-	unsigned long flags;
-
-	assert(cxt);
-	assert(cxt->fs);
-
-	if (try_type && !cxt->helper) {
-		rc = mnt_context_prepare_helper(cxt, MNT_ACT_MOUNT, try_type);
-		if (!rc)
-			return rc;
-	}
-	if (cxt->helper)
-		return exec_mount_helper(cxt);
-
-	type = try_type ? : mnt_fs_get_fstype(cxt->fs);
-
-	flags = cxt->mountflags;
-	src = mnt_fs_get_srcpath(cxt->fs);
-	target = mnt_fs_get_target(cxt->fs);
-
-	if (!src || !target)
-		return -EINVAL;
-
-	if (!(flags & MS_MGC_MSK))
-		flags |= MS_MGC_VAL;
-
-	DBG(CXT, mnt_debug_h(cxt, "calling mount(2) "
-			"[source=%s, target=%s, type=%s, "
-			" mountflags=%08lx, mountdata=%s]",
-			src, target, type,
-			flags, cxt->mountdata ? "yes" : "<none>"));
-
-	if (mount(src, target, type, flags, cxt->mountdata)) {
-		cxt->syscall_errno = errno;
-		DBG(CXT, mnt_debug_h(cxt, "mount(2) failed [errno=%d]",
-						cxt->syscall_errno));
-		return -cxt->syscall_errno;
-	}
-
-	DBG(CXT, mnt_debug_h(cxt, "mount(2) success"));
-	return 0;
-}
-
-/**
- * mnt_context_mount_fs:
- * @cxt: mount context
- *
- * Mount filesystem by mount(2) or fork()+exec(/sbin/mount.<type>).
- *
- * See also mnt_context_disable_helpers().
- *
- * Returns: 0 on success, and negative number in case of error.
- */
-int mnt_context_mount_fs(mnt_context *cxt)
-{
-	int rc = -EINVAL;
-	const char *type;
-
-	if (!cxt || !cxt->fs || (cxt->fs->flags & MNT_FS_SWAP))
-		return -EINVAL;
-
-	if (!(cxt->flags & MNT_FL_MOUNTDATA))
-		cxt->mountdata = (char *) mnt_fs_get_fs_optstr(cxt->fs);
-
-	type = mnt_fs_get_fstype(cxt->fs);
-
-	if (type && !strchr(type, ',')) {
-		rc = mnt_context_do_mount(cxt, NULL);
-		if (rc)
-			return rc;
-	}
-
-	/* TODO: try all filesystems from comma separated list of types */
-
-	/* TODO: try all filesystems from /proc/filesystems and /etc/filesystems */
-
-	return rc;
-}
-
-/**
- * mnt_context_post_mount:
- * @cxt: mount context
- *
- * Updates mtab, etc. This function should be always called after
- * mnt_context_do_mount().
- *
- * Returns: 0 on success, and negative number in case of error.
- */
-int mnt_context_post_mount(mnt_context *cxt)
-{
-	int rc = 0;
-
-	if (!cxt)
-		return -EINVAL;
-	/*
-	 * Update /etc/mtab or /var/run/mount/mountinfo
-	 */
-	if (!cxt->syscall_errno && !cxt->helper &&
-	    !(cxt->flags & MNT_FL_NOMTAB) &&
-	    cxt->update && !mnt_update_is_pointless(cxt->update)) {
-
-		/* TODO: if mtab update is expected then checkif the target is really
-		 *       mounted read-write to avoid 'ro' in mtab and 'rw' in /proc/mounts.
-		 */
-		rc = mnt_update_file(cxt->update);
-	}
-
-	return rc;
-}
-
-/**
- * mnt_context_get_mount_error:
- * @cxt: mount context
- * @buf: buffer for error message
- * @bufsiz: size of buffer
- *
- * Generates human readable error message for failed mnt_context_mount_fs().
- *
- * Returns: 0 on success, and negative number in case of error.
- */
-int mnt_context_get_mount_error(mnt_context *cxt, char *buf, size_t bufsiz)
-{
-	/* TODO: based on cxt->syscall_errno or cxt->helper_status */
-	return 0;
-}
-
-#ifdef TEST_PROGRAM
-
-mnt_lock *lock;
-
-static void lock_fallback(void)
-{
-	if (lock) {
-		mnt_unlock_file(lock);
-		mnt_free_lock(lock);
-	}
-}
-
-int test_mount(struct mtest *ts, int argc, char *argv[])
-{
-	int idx = 1, rc = 0;
-	mnt_context *cxt;
-
-	if (argc < 2)
-		return -EINVAL;
-
-	cxt = mnt_new_context();
-	if (!cxt)
-		return -ENOMEM;
-
-	if (!strcmp(argv[idx], "-o")) {
-		mnt_context_set_optstr(cxt, argv[idx + 1]);
-		idx += 2;
-	}
-	if (!strcmp(argv[idx], "-t")) {
-		/* TODO: use mnt_context_set_fstype_pattern() */
-		mnt_context_set_fstype(cxt, argv[idx + 1]);
-		idx += 2;
-	}
-
-	if (argc == idx + 1)
-		/* mount <spec> */
-		mnt_context_set_spec(cxt, argv[idx++]);
-
-	else if (argc == idx + 2) {
-		/* mount <device> <mountpoint> */
-		mnt_context_set_source(cxt, argv[idx++]);
-		mnt_context_set_target(cxt, argv[idx++]);
-	}
-
-	rc = mnt_context_prepare_mount(cxt);
-	if (rc)
-		printf("failed to prepare mount\n");
-	else {
-		lock = mnt_context_get_lock(cxt);
-		if (lock)
-			atexit(lock_fallback);
-
-		rc = mnt_context_mount_fs(cxt);
-		if (rc)
-			printf("failed to mount\n");
-		else {
-			printf("successfully mounted");
-			rc = mnt_context_post_mount(cxt);
-			if (rc)
-				printf("mtab update failed\n");
-		}
-	}
-
-	mnt_free_context(cxt);
-	return rc;
-}
-
-int main(int argc, char *argv[])
-{
-	struct mtest tss[] = {
-	{ "--mount",    test_mount,        "[-o <opts>] [-t <type>] <spec> | <src> <target>" },
-	{ NULL }
-	};
-
-	return mnt_run_test(tss, argc, argv);
-}
-
-#endif /* TEST_PROGRAM */