For snapshots we need all VOP_LOCKs to be exclusive.

The "business class upgrade" was implemented in UFS's VOP_LOCK
implementation ufs_lock() which is the wrong layer, so move it to
ffs_lock().

Also, as long as we have not abandonned advanced vfs-stacking we
should not preclude it from happening: instead of implementing a
copy locally, use the VOP_LOCK_APV(&ufs) to correctly arrive at
vop_stdlock() at the bottom.

2 files changed, 24 insertions, 29 deletions

diff --git a/sys/ufs/ffs/ffs_vnops.c b/sys/ufs/ffs/ffs_vnops.c
index e0aae3c..f9a7994 100644
--- a/sys/ufs/ffs/ffs_vnops.c
+++ b/sys/ufs/ffs/ffs_vnops.c
@@ -97,11 +97,13 @@ __FBSDID("$FreeBSD$");
 #include <ufs/ffs/fs.h>
 #include <ufs/ffs/ffs_extern.h>
 #include "opt_directio.h"
+#include "opt_ffs.h"
 
 #ifdef DIRECTIO
 extern int	ffs_rawread(struct vnode *vp, struct uio *uio, int *workdone);
 #endif
 static vop_fsync_t	ffs_fsync;
+static vop_lock_t	ffs_lock;
 static vop_getpages_t	ffs_getpages;
 static vop_read_t	ffs_read;
 static vop_write_t	ffs_write;
@@ -122,6 +124,7 @@ struct vop_vector ffs_vnodeops = {
 	.vop_default =		&ufs_vnodeops,
 	.vop_fsync =		ffs_fsync,
 	.vop_getpages =		ffs_getpages,
+	.vop_lock =		ffs_lock,
 	.vop_read =		ffs_read,
 	.vop_reallocblks =	ffs_reallocblks,
 	.vop_write =		ffs_write,
@@ -136,6 +139,7 @@ struct vop_vector ffs_vnodeops = {
 struct vop_vector ffs_fifoops = {
 	.vop_default =		&ufs_fifoops,
 	.vop_fsync =		ffs_fsync,
+	.vop_lock =		ffs_lock,
 	.vop_reallocblks =	ffs_reallocblks,
 	.vop_strategy =		ffsext_strategy,
 	.vop_closeextattr =	ffs_closeextattr,
@@ -302,6 +306,26 @@ loop:
 	return (UFS_UPDATE(vp, wait));
 }
 
+/*
+ * Snapshots require all lock requests to be exclusive.
+ */
+static int
+ffs_lock(ap)
+	struct vop_lock_args /* {
+		struct vnode *a_vp;
+		int a_flags;
+		struct thread *a_td;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+
+	if ((VTOI(vp)->i_flags & SF_SNAPSHOT) &&
+	    ((ap->a_flags & LK_TYPE_MASK) == LK_SHARED)) {
+		ap->a_flags &= ~LK_TYPE_MASK;
+		ap->a_flags |= LK_EXCLUSIVE;
+	}
+	return (VOP_LOCK_APV(&ufs_vnodeops, ap));
+}
 
 /*
  * Vnode op for reading.
diff --git a/sys/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index 3f86f38..baaffb5 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -97,7 +97,6 @@ static vop_mkdir_t	ufs_mkdir;
 static vop_mknod_t	ufs_mknod;
 static vop_open_t	ufs_open;
 static vop_pathconf_t	ufs_pathconf;
-static vop_lock_t	ufs_lock;
 static vop_print_t	ufs_print;
 static vop_readlink_t	ufs_readlink;
 static vop_remove_t	ufs_remove;
@@ -1950,33 +1949,6 @@ ufs_strategy(ap)
 }
 
 /*
- * Snapshots require all lock requests to be exclusive.
- */
-static int
-ufs_lock(ap)
-	struct vop_lock_args /* {
-		struct vnode *a_vp;
-		int a_flags;
-		struct thread *a_td;
-	} */ *ap;
-{
-	struct vnode *vp = ap->a_vp;
-	int flags = ap->a_flags;
-
-	if ((VTOI(vp)->i_flags & SF_SNAPSHOT) &&
-	    ((flags & LK_TYPE_MASK) == LK_SHARED)) {
-		flags &= ~LK_TYPE_MASK;
-		flags |= LK_EXCLUSIVE;
-	}
-#ifndef	DEBUG_LOCKS
-	return (lockmgr(vp->v_vnlock, flags, VI_MTX(vp), ap->a_td));
-#else
-	return (debuglockmgr(vp->v_vnlock, flags, VI_MTX(vp),
-	    ap->a_td, "vop_stdlock", vp->filename, vp->line));
-#endif
-}
-
-/*
  * Print out the contents of an inode.
  */
 static int
@@ -2525,7 +2497,6 @@ struct vop_vector ufs_vnodeops = {
 	.vop_write =		VOP_PANIC,
 	.vop_access =		ufs_access,
 	.vop_advlock =		ufs_advlock,
-	.vop_lock =		ufs_lock,
 	.vop_bmap =		ufs_bmap,
 	.vop_cachedlookup =	ufs_lookup,
 	.vop_close =		ufs_close,