libmount: split mnt_context_do_mount()

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

6 files changed, 108 insertions, 22 deletions

diff --git a/shlibs/mount/samples/mount.c b/shlibs/mount/samples/mount.c
index 1d032a621..eca02d62e 100644
--- a/shlibs/mount/samples/mount.c
+++ b/shlibs/mount/samples/mount.c
@@ -408,7 +408,7 @@ int main(int argc, char **argv)
 	if (lock)
 		atexit(lock_atexit_cleanup);
 
-	rc = mnt_context_do_mount(cxt);
+	rc = mnt_mount_context(cxt);
 	if (rc) {
 		/* TODO: call mnt_context_strerror() */
 		rc = EX_FAIL;
diff --git a/shlibs/mount/src/context.c b/shlibs/mount/src/context.c
index d71cbb63c..aad0b3930 100644
--- a/shlibs/mount/src/context.c
+++ b/shlibs/mount/src/context.c
@@ -1500,7 +1500,7 @@ int test_mount(struct mtest *ts, int argc, char *argv[])
 	if (lock)
 		atexit(lock_fallback);
 
-	rc = mnt_context_do_mount(cxt);
+	rc = mnt_mount_context(cxt);
 	if (rc)
 		printf("failed to mount %s\n", strerror(errno));
 	else
diff --git a/shlibs/mount/src/context_mount.c b/shlibs/mount/src/context_mount.c
index 1180d8eb0..55cf48bf8 100644
--- a/shlibs/mount/src/context_mount.c
+++ b/shlibs/mount/src/context_mount.c
@@ -343,7 +343,9 @@ static int do_mount(mnt_context *cxt, const char *try_type)
 			src, target, type,
 			flags, cxt->mountdata ? "yes" : "<none>"));
 
-	if (!(cxt->flags & MNT_FL_FAKE)) {
+	if (cxt->flags & MNT_FL_FAKE)
+		cxt->syscall_status = 0;
+	else {
 		if (mount(src, target, type, flags, cxt->mountdata)) {
 			cxt->syscall_status = -errno;
 			DBG(CXT, mnt_debug_h(cxt, "mount(2) failed [errno=%d %m]",
@@ -420,21 +422,16 @@ static int do_mount_by_pattern(mnt_context *cxt, const char *pattern)
 }
 
 /**
- * mnt_context_do_mount:
- * @cxt: mount context
+ * mnt_context_prepare_mount:
+ * @cxt: context
  *
- * Mount filesystem by mount(2) or fork()+exec(/sbin/mount.type).
- *
- * See also mnt_context_disable_helpers().
+ * Prepare context for mounting, unnecessary for mnt_context_mount().
  *
- * Returns: 0 on success, and negative number in case of error. WARNING: error
- *          does not mean that mount(2) syscall or mount.type helper wasn't
- *          sucessfully called. Check mnt_context_get_status() after error!
+ * Returns: negative number on error, zero on success
  */
-int mnt_context_do_mount(mnt_context *cxt)
+int mnt_context_prepare_mount(mnt_context *cxt)
 {
-	int rc = -EINVAL, x;
-	const char *type;
+	int rc = -EINVAL;
 
 	assert(cxt);
 	assert(cxt->fs);
@@ -446,6 +443,9 @@ int mnt_context_do_mount(mnt_context *cxt)
 	if (!mnt_fs_get_source(cxt->fs) && !mnt_fs_get_target(cxt->fs))
 		return -EINVAL;
 
+	if (cxt->flags & MNT_FL_PREPARED)
+		return 0;
+
 	cxt->action = MNT_ACT_MOUNT;
 
 	DBG(CXT, mnt_debug_h(cxt, "mount: preparing"));
@@ -466,13 +466,32 @@ int mnt_context_do_mount(mnt_context *cxt)
 		rc = mnt_context_guess_fstype(cxt);
 	if (!rc)
 		rc = mnt_context_prepare_helper(cxt, "mount", NULL);
-	if (!rc)
-		rc = mnt_context_prepare_update(cxt);
-
 	if (rc) {
 		DBG(CXT, mnt_debug_h(cxt, "mount: preparing failed"));
 		return rc;
 	}
+	cxt->flags |= MNT_FL_PREPARED;
+	return rc;
+}
+
+/**
+ * mnt_context_do_mount
+ * @cxt: context
+ *
+ * Call mount(2) or mount.<type> helper. Unnecessary for mnt_context_mount().
+ *
+ * Returns: negative number on error, zero on success
+ */
+int mnt_context_do_mount(mnt_context *cxt)
+{
+	const char *type;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->helper_exec_status == 1);
+	assert(cxt->syscall_status == 1);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+	assert((cxt->flags & MNT_FL_PREPARED));
 
 	DBG(CXT, mnt_debug_h(cxt, "mount: do mount"));
 
@@ -481,15 +500,73 @@ int mnt_context_do_mount(mnt_context *cxt)
 
 	type = mnt_fs_get_fstype(cxt->fs);
 	if (type)
-		rc = do_mount(cxt, NULL);
-	else
-		rc = do_mount_by_pattern(cxt, cxt->fstype_pattern);
+		return do_mount(cxt, NULL);
+
+	return do_mount_by_pattern(cxt, cxt->fstype_pattern);
+}
+
+/**
+ * mnt_mount_context:
+ * @cxt: mount context
+ *
+ * Mount filesystem by mount(2) or fork()+exec(/sbin/mount.type).
+ *
+ * This is top-level function for FS mounting, similar to:
+ *
+ *	mnt_context_prepare_mount(cxt);
+ *	mnt_context_do_mount(cxt);
+ *	mnt_context_finalize_mount(cxt);
+ *
+ * See also mnt_context_disable_helpers().
+ *
+ * Returns: 0 on success, and negative number in case of error. WARNING: error
+ *          does not mean that mount(2) syscall or mount.type helper wasn't
+ *          sucessfully called. Check mnt_context_get_status() after error!
+ */
+int mnt_mount_context(mnt_context *cxt)
+{
+	int rc;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert(cxt->helper_exec_status == 1);
+	assert(cxt->syscall_status == 1);
+
+	rc = mnt_context_prepare_mount(cxt);
+	if (!rc)
+		rc = mnt_context_prepare_update(cxt);
+	if (!rc)
+		rc = mnt_context_do_mount(cxt);
 
 	/* TODO: if mtab update is expected then check if the
 	 * target is really mounted read-write to avoid 'ro' in
 	 * mtab and 'rw' in /proc/mounts.
 	 */
-	x = mnt_context_update_tabs(cxt);
-	return rc ? rc : x;
+	if (!rc)
+		rc = mnt_context_update_tabs(cxt);
+	return rc;
+}
+
+/**
+ * mnt_context_finalize_mount:
+ * @cxt: context
+ *
+ * Mtab update, etc. Unnecessary for mnt_context_mount().
+ *
+ * Returns: negative number on error, 0 on success.
+ */
+int mnt_context_finalize_mount(mnt_context *cxt)
+{
+	int rc;
+
+	assert(cxt);
+	assert(cxt->fs);
+	assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
+	assert((cxt->flags & MNT_FL_PREPARED));
+
+	rc = mnt_context_prepare_update(cxt);
+	if (!rc)
+		rc = mnt_context_update_tabs(cxt);;
+	return rc;
 }
 
diff --git a/shlibs/mount/src/mount.h.in b/shlibs/mount/src/mount.h.in
index 828bf7083..84f768477 100644
--- a/shlibs/mount/src/mount.h.in
+++ b/shlibs/mount/src/mount.h.in
@@ -381,7 +381,12 @@ extern int mnt_context_apply_fstab(mnt_context *cxt);
 extern int mnt_context_get_status(mnt_context *cxt);
 extern int mnt_context_strerror(mnt_context *cxt, char *buf, size_t bufsiz);
 
+extern int mnt_mount_context(mnt_context *cxt);
+
+extern int mnt_context_prepare_mount(mnt_context *cxt);
 extern int mnt_context_do_mount(mnt_context *cxt);
+extern int mnt_context_finalize_mount(mnt_context *cxt);
+
 extern int mnt_context_do_umount(mnt_context *cxt);
 
 /*
diff --git a/shlibs/mount/src/mount.sym b/shlibs/mount/src/mount.sym
index 3ad4a0210..e29372ed5 100644
--- a/shlibs/mount/src/mount.sym
+++ b/shlibs/mount/src/mount.sym
@@ -22,6 +22,7 @@ global:
 	mnt_context_enable_rdonly_umount;
 	mnt_context_enable_sloppy;
 	mnt_context_enable_verbose;
+	mnt_context_finalize_mount;
 	mnt_context_get_cache;
 	mnt_context_get_fs;
 	mnt_context_get_fstab;
@@ -39,6 +40,7 @@ global:
 	mnt_context_is_restricted;
 	mnt_context_is_sloppy;
 	mnt_context_is_verbose;
+	mnt_context_prepare_mount;
 	mnt_context_set_cache;
 	mnt_context_set_fs;
 	mnt_context_set_fstab;
@@ -125,6 +127,7 @@ global:
 	mnt_mangle;
 	mnt_match_fstype;
 	mnt_match_options;
+	mnt_mount_context;
 	mnt_new_cache;
 	mnt_new_context;
 	mnt_new_fs;
diff --git a/shlibs/mount/src/mountP.h b/shlibs/mount/src/mountP.h
index ac46599da..cb7b68cd3 100644
--- a/shlibs/mount/src/mountP.h
+++ b/shlibs/mount/src/mountP.h
@@ -286,6 +286,7 @@ struct _mnt_context
 #define MNT_FL_TAB_APPLIED	(1 << 21)	/* mtab/fstab merged to cxt->fs */
 #define MNT_FL_MOUNTFLAGS_MERGED (1 << 22)	/* MS_* flags was read from optstr */
 #define MNT_FL_SAVED_USER	(1 << 23)
+#define MNT_FL_PREPARED		(1 << 24)
 
 /* default flags */
 #define MNT_FL_DEFAULT		0