Reviewed by: jlemon

An initial tidyup of the mount() syscall and VFS mount code.

This code replaces the earlier work done by jlemon in an attempt to
make linux_mount() work.

* the guts of the mount work has been moved into vfs_mount().

* move `type', `path' and `flags' from being userland variables into being
  kernel variables in vfs_mount(). `data' remains a pointer into
  userspace.

* Attempt to verify the `type' and `path' strings passed to vfs_mount()
  aren't too long.

* rework mount() and linux_mount() to take the userland parameters
  (besides data, as mentioned) and pass kernel variables to vfs_mount().
  (linux_mount() already did this, I've just tidied it up a little more.)

* remove the copyin*() stuff for `path'. `data' still requires copyin*()
  since its a pointer into userland.

* set `mount->mnt_statf_mntonname' in vfs_mount() rather than in each
  filesystem.  This variable is generally initialised with `path', and
  each filesystem can override it if they want to.

* NOTE: f_mntonname is intiailised with "/" in the case of a root mount.

11 files changed, 10 insertions, 46 deletions

diff --git a/sys/fs/cd9660/cd9660_vfsops.c b/sys/fs/cd9660/cd9660_vfsops.c
index 3017339..606f9d3 100644
--- a/sys/fs/cd9660/cd9660_vfsops.c
+++ b/sys/fs/cd9660/cd9660_vfsops.c
@@ -249,8 +249,6 @@ cd9660_mount(mp, path, data, ndp, p)
 		return error;
 	}
 	imp = VFSTOISOFS(mp);
-	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
 	    &size);
 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
diff --git a/sys/fs/devfs/devfs_vfsops.c b/sys/fs/devfs/devfs_vfsops.c
index eb13d8f..ee369e1 100644
--- a/sys/fs/devfs/devfs_vfsops.c
+++ b/sys/fs/devfs/devfs_vfsops.c
@@ -67,7 +67,6 @@ devfs_mount(mp, path, data, ndp, p)
 	struct proc *p;
 {
 	int error;
-	size_t size;
 	struct devfs_mount *fmp;
 	struct vnode *rvp;
 
@@ -100,13 +99,6 @@ devfs_mount(mp, path, data, ndp, p)
 	}
 	VOP_UNLOCK(rvp, 0, p);
 
-	if (path != NULL) {
-		(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	} else {
-		strcpy(mp->mnt_stat.f_mntonname, "/");
-		size = 1;
-	}
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
 	bcopy("devfs", mp->mnt_stat.f_mntfromname, sizeof("devfs"));
 	(void)devfs_statfs(mp, &mp->mnt_stat, p);
diff --git a/sys/fs/fdescfs/fdesc_vfsops.c b/sys/fs/fdescfs/fdesc_vfsops.c
index 84940c7..7737e37 100644
--- a/sys/fs/fdescfs/fdesc_vfsops.c
+++ b/sys/fs/fdescfs/fdesc_vfsops.c
@@ -74,7 +74,6 @@ fdesc_mount(mp, path, data, ndp, p)
 	struct proc *p;
 {
 	int error = 0;
-	u_int size;
 	struct fdescmount *fmp;
 	struct vnode *rvp;
 
@@ -98,8 +97,6 @@ fdesc_mount(mp, path, data, ndp, p)
 	mp->mnt_data = (qaddr_t) fmp;
 	vfs_getnewfsid(mp);
 
-	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
 	bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc"));
 	(void)fdesc_statfs(mp, &mp->mnt_stat, p);
diff --git a/sys/fs/hpfs/hpfs_vfsops.c b/sys/fs/hpfs/hpfs_vfsops.c
index 1581851..2d40b2d 100644
--- a/sys/fs/hpfs/hpfs_vfsops.c
+++ b/sys/fs/hpfs/hpfs_vfsops.c
@@ -272,16 +272,12 @@ hpfs_mount (
 	/*
 	 * Since this is a new mount, we want the names for
 	 * the device and the mount point copied in.  If an
-	 * error occurs,  the mountpoint is discarded by the
-	 * upper level code.
+	 * error occurs, the mountpoint is discarded by the
+	 * upper level code.  Note that vfs_mount() handles
+	 * copying the mountpoint f_mntonname for us, so we
+	 * don't have to do it here unless we want to set it
+	 * to something other than "path" for some rason.
 	 */
-	/* Save "last mounted on" info for mount point (NULL pad)*/
-	copyinstr(	path,				/* mount point*/
-			mp->mnt_stat.f_mntonname,	/* save area*/
-			MNAMELEN - 1,			/* max size*/
-			&size);				/* real size*/
-	bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
-
 	/* Save "mounted from" info for mount point (NULL pad)*/
 	copyinstr(	args.fspec,			/* device name*/
 			mp->mnt_stat.f_mntfromname,	/* save area*/
diff --git a/sys/fs/msdosfs/msdosfs_vfsops.c b/sys/fs/msdosfs/msdosfs_vfsops.c
index 3088d7a..672ea5d 100644
--- a/sys/fs/msdosfs/msdosfs_vfsops.c
+++ b/sys/fs/msdosfs/msdosfs_vfsops.c
@@ -345,9 +345,6 @@ msdosfs_mount(mp, path, data, ndp, p)
 		msdosfs_unmount(mp, MNT_FORCE, p);
 		return error;
 	}
-
-	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
 	    &size);
 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
diff --git a/sys/fs/ntfs/ntfs_vfsops.c b/sys/fs/ntfs/ntfs_vfsops.c
index 384883e..89a7dd7 100644
--- a/sys/fs/ntfs/ntfs_vfsops.c
+++ b/sys/fs/ntfs/ntfs_vfsops.c
@@ -376,16 +376,12 @@ ntfs_mount (
 		/*
 		 * Since this is a new mount, we want the names for
 		 * the device and the mount point copied in.  If an
-		 * error occurs,  the mountpoint is discarded by the
-		 * upper level code.
+		 * error occurs, the mountpoint is discarded by the
+		 * upper level code.  Note that vfs_mount() handles
+		 * copying the mountpoint f_mntonname for us, so we
+		 * don't have to do it here unless we want to set it
+		 * to something other than "path" for some rason.
 		 */
-		/* Save "last mounted on" info for mount point (NULL pad)*/
-		copyinstr(	path,				/* mount point*/
-				mp->mnt_stat.f_mntonname,	/* save area*/
-				MNAMELEN - 1,			/* max size*/
-				&size);				/* real size*/
-		bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
-
 		/* Save "mounted from" info for mount point (NULL pad)*/
 		copyinstr(	args.fspec,			/* device name*/
 				mp->mnt_stat.f_mntfromname,	/* save area*/
diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c
index 3339162..b852cc4 100644
--- a/sys/fs/nullfs/null_vfsops.c
+++ b/sys/fs/nullfs/null_vfsops.c
@@ -191,8 +191,6 @@ nullfs_mount(mp, path, data, ndp, p)
 	mp->mnt_data = (qaddr_t) xmp;
 	vfs_getnewfsid(mp);
 
-	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
 	(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
 	    &size);
 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
diff --git a/sys/fs/nwfs/nwfs_vfsops.c b/sys/fs/nwfs/nwfs_vfsops.c
index 3e76b30..7d17e7d 100644
--- a/sys/fs/nwfs/nwfs_vfsops.c
+++ b/sys/fs/nwfs/nwfs_vfsops.c
@@ -146,7 +146,6 @@ static int nwfs_mount(struct mount *mp, char *path, caddr_t data,
 		      struct nameidata *ndp, struct proc *p)
 {
 	struct nwfs_args args; 	  /* will hold data from mount request */
-	size_t size;
 	int error;
 	struct nwmount *nmp = NULL;
 	struct ncp_conn *conn = NULL;
@@ -198,8 +197,6 @@ static int nwfs_mount(struct mount *mp, char *path, caddr_t data,
 	nmp->m.dir_mode  = (nmp->m.dir_mode &
 			    (S_IRWXU|S_IRWXG|S_IRWXO)) | S_IFDIR;
 	if ((error = nwfs_initnls(nmp)) != 0) goto bad;
-	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
 	pc = mp->mnt_stat.f_mntfromname;
 	pe = pc+sizeof(mp->mnt_stat.f_mntfromname);
 	bzero(pc, MNAMELEN);
diff --git a/sys/fs/portalfs/portal_vfsops.c b/sys/fs/portalfs/portal_vfsops.c
index 139746d..3f7903c 100644
--- a/sys/fs/portalfs/portal_vfsops.c
+++ b/sys/fs/portalfs/portal_vfsops.c
@@ -133,8 +133,6 @@ portal_mount(mp, path, data, ndp, p)
 	mp->mnt_data = (qaddr_t) fmp;
 	vfs_getnewfsid(mp);
 
-	(void)copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
 	(void)copyinstr(args.pa_config,
 	    mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
diff --git a/sys/fs/umapfs/umap_vfsops.c b/sys/fs/umapfs/umap_vfsops.c
index 6457897..768ad48 100644
--- a/sys/fs/umapfs/umap_vfsops.c
+++ b/sys/fs/umapfs/umap_vfsops.c
@@ -221,8 +221,6 @@ umapfs_mount(mp, path, data, ndp, p)
 	mp->mnt_data = (qaddr_t) amp;
 	vfs_getnewfsid(mp);
 
-	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
 	(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
 	    &size);
 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
diff --git a/sys/fs/unionfs/union_vfsops.c b/sys/fs/unionfs/union_vfsops.c
index dfa6eae..5018f09 100644
--- a/sys/fs/unionfs/union_vfsops.c
+++ b/sys/fs/unionfs/union_vfsops.c
@@ -253,9 +253,6 @@ union_mount(mp, path, data, ndp, p)
 	mp->mnt_data = (qaddr_t) um;
 	vfs_getnewfsid(mp);
 
-	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
-	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
-
 	switch (um->um_op) {
 	case UNMNT_ABOVE:
 		cp = "<above>:";