Assert that the msdosfs vnode is (e)locked in several places.

The plan is to use vnode lock to protect denode and fat cache,
and having separate lock for block use map.

Change the check and return on impossible condition into KASSERT().

Tested by:	pho
MFC after:	3 weeks

2 files changed, 8 insertions, 8 deletions

diff --git a/sys/fs/msdosfs/msdosfs_denode.c b/sys/fs/msdosfs/msdosfs_denode.c
index b689b5d..0399a59 100644
--- a/sys/fs/msdosfs/msdosfs_denode.c
+++ b/sys/fs/msdosfs/msdosfs_denode.c
@@ -167,9 +167,8 @@ deget(pmp, dirclust, diroffset, depp)
 	ldep->de_dirclust = dirclust;
 	ldep->de_diroffset = diroffset;
 	ldep->de_inode = inode;
-	fc_purge(ldep, 0);	/* init the fat cache for this denode */
-
 	lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL);
+	fc_purge(ldep, 0);	/* init the fat cache for this denode */
 	error = insmntque(nvp, mntp);
 	if (error != 0) {
 		free(ldep, M_MSDOSFSNODE);
diff --git a/sys/fs/msdosfs/msdosfs_fat.c b/sys/fs/msdosfs/msdosfs_fat.c
index 9677a7a..bb71d63 100644
--- a/sys/fs/msdosfs/msdosfs_fat.c
+++ b/sys/fs/msdosfs/msdosfs_fat.c
@@ -139,12 +139,9 @@ pcbmap(dep, findcn, bnp, cnp, sp)
 	struct msdosfsmount *pmp = dep->de_pmp;
 	u_long bsize;
 
-	/*
-	 * If they don't give us someplace to return a value then don't
-	 * bother doing anything.
-	 */
-	if (bnp == NULL && cnp == NULL && sp == NULL)
-		return (0);
+	KASSERT(bnp != NULL || cnp != NULL || sp != NULL,
+	    ("pcbmap: extra call"));
+	ASSERT_VOP_ELOCKED(DETOV(dep), "pcbmap");
 
 	cn = dep->de_StartCluster;
 	/*
@@ -270,6 +267,8 @@ fc_lookup(dep, findcn, frcnp, fsrcnp)
 	u_long cn;
 	struct fatcache *closest = 0;
 
+	ASSERT_VOP_LOCKED(DETOV(dep), "fc_lookup");
+
 	for (i = 0; i < FC_SIZE; i++) {
 		cn = dep->de_fc[i].fc_frcn;
 		if (cn != FCE_EMPTY && cn <= findcn) {
@@ -295,6 +294,8 @@ fc_purge(dep, frcn)
 	int i;
 	struct fatcache *fcp;
 
+	ASSERT_VOP_ELOCKED(DETOV(dep), "fc_purge");
+
 	fcp = dep->de_fc;
 	for (i = 0; i < FC_SIZE; i++, fcp++) {
 		if (fcp->fc_frcn >= frcn)