Introduce vfs_byname_kld() which will try to load the filesystem

as a module if possible.

Use it so we don't have linker magic in the middle of the already
complex mount code.

3 files changed, 41 insertions, 29 deletions

diff --git a/sys/kern/vfs_init.c b/sys/kern/vfs_init.c
index 343f5f7..1b1e419 100644
--- a/sys/kern/vfs_init.c
+++ b/sys/kern/vfs_init.c
@@ -40,7 +40,9 @@ __FBSDID("$FreeBSD$");
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
+#include <sys/linker.h>
 #include <sys/mount.h>
+#include <sys/proc.h>
 #include <sys/sysctl.h>
 #include <sys/vnode.h>
 #include <sys/malloc.h>
@@ -124,6 +126,41 @@ vfs_byname(const char *name)
 	return (NULL);
 }
 
+struct vfsconf *
+vfs_byname_kld(const char *fstype, struct thread *td, int *error)
+{
+	struct vfsconf *vfsp;
+	linker_file_t lf;
+
+	vfsp = vfs_byname(fstype);
+	if (vfsp != NULL)
+		return (vfsp);
+
+	/* Only load modules for root (very important!). */
+	*error = suser(td);
+	if (*error)
+		return (NULL);
+	*error = securelevel_gt(td->td_ucred, 0);
+	if (*error) 
+		return (NULL);
+	*error = linker_load_module(NULL, fstype, NULL, NULL, &lf);
+	if (lf == NULL)
+		*error = ENODEV;
+	if (*error)
+		return (NULL);
+	lf->userrefs++;
+	/* Look up again to see if the VFS was loaded. */
+	vfsp = vfs_byname(fstype);
+	if (vfsp == NULL) {
+		lf->userrefs--;
+		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
+		*error = ENODEV;
+		return (NULL);
+	}
+	return (vfsp);
+}
+
+
 /* Register a new filesystem type in the global table */
 int
 vfs_register(struct vfsconf *vfc)
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c
index 0211de3..e93790f 100644
--- a/sys/kern/vfs_mount.c
+++ b/sys/kern/vfs_mount.c
@@ -66,7 +66,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/cons.h>
 #include <sys/jail.h>
 #include <sys/kernel.h>
-#include <sys/linker.h>
 #include <sys/mac.h>
 #include <sys/malloc.h>
 #include <sys/mount.h>
@@ -669,7 +668,6 @@ vfs_domount(
 	int compat		/* Invocation from compat syscall. */
 	)
 {
-	linker_file_t lf;
 	struct vnode *vp;
 	struct mount *mp;
 	struct vfsconf *vfsp;
@@ -786,34 +784,10 @@ vfs_domount(
 			vput(vp);
 			return (ENOTDIR);
 		}
-		vfsp = vfs_byname(fstype);
+		vfsp = vfs_byname_kld(fstype, td, &error);
 		if (vfsp == NULL) {
-			/* Only load modules for root (very important!). */
-			if ((error = suser(td)) != 0) {
-				vput(vp);
-				return (error);
-			}
-			error = securelevel_gt(td->td_ucred, 0);
-			if (error) {
-				vput(vp);
-				return (error);
-			}
-			error = linker_load_module(NULL, fstype, NULL, NULL, &lf);
-			if (error || lf == NULL) {
-				vput(vp);
-				if (lf == NULL)
-					error = ENODEV;
-				return (error);
-			}
-			lf->userrefs++;
-			/* Look up again to see if the VFS was loaded. */
-			vfsp = vfs_byname(fstype);
-			if (vfsp == NULL) {
-				lf->userrefs--;
-				linker_file_unload(lf, LINKER_UNLOAD_FORCE);
-				vput(vp);
-				return (ENODEV);
-			}
+			vput(vp);
+			return (error);
 		}
 		VI_LOCK(vp);
 		if ((vp->v_iflag & VI_MOUNT) != 0 ||
diff --git a/sys/sys/mount.h b/sys/sys/mount.h
index 237ba6b..930948c 100644
--- a/sys/sys/mount.h
+++ b/sys/sys/mount.h
@@ -564,6 +564,7 @@ int	dounmount(struct mount *, int, struct thread *);
 int	kernel_mount(struct iovec *, u_int, int);
 int	kernel_vmount(int flags, ...);
 struct vfsconf *vfs_byname(const char *);
+struct vfsconf *vfs_byname_kld(const char *, struct thread *td, int *);
 void	vfs_event_signal(fsid_t *, u_int32_t, intptr_t);
 int	vfs_getopt(struct vfsoptlist *, const char *, void **, int *);
 int	vfs_copyopt(struct vfsoptlist *, const char *, void *, int);