Index: sys/vm/vm_page.h
===================================================================
--- sys/vm/vm_page.h
+++ sys/vm/vm_page.h
@@ -511,10 +511,9 @@
 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
 
 /*
- * Page allocation parameters for vm_page for the functions
- * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and
- * vm_page_alloc_freelist().  Some functions support only a subset
- * of the flags, and ignore others, see the flags legend.
+ * Page allocation parameters for vm_page for the functions vm_page_alloc(),
+ * vm_page_grab() and vm_page_alloc_contig().  Some functions support only a
+ * subset of the flags, and ignore others, see the flags legend.
  *
  * The meaning of VM_ALLOC_ZERO differs slightly between the vm_page_alloc*()
  * and the vm_page_grab*() functions.  See these functions for details.
@@ -525,7 +524,7 @@
  * (a) - vm_page_alloc() supports the flag.
  * (c) - vm_page_alloc_contig() supports the flag.
  * (g) - vm_page_grab() supports the flag.
- * (n) - vm_page_alloc_noobj() and vm_page_alloc_freelist() support the flag.
+ * (n) - vm_page_alloc_noobj() supports the flag.
  * (p) - vm_page_grab_pages() supports the flag.
  * Bits above 15 define the count of additional pages that the caller
  * intends to allocate.
@@ -534,7 +533,7 @@
 #define VM_ALLOC_INTERRUPT	1
 #define VM_ALLOC_SYSTEM		2
 #define	VM_ALLOC_CLASS_MASK	3
-#define	VM_ALLOC_WAITOK		0x0008	/* (acn) Sleep and retry */
+#define	VM_ALLOC_WAITOK		0x0008	/* (n) Sleep and retry */
 #define	VM_ALLOC_WAITFAIL	0x0010	/* (acn) Sleep and return error */
 #define	VM_ALLOC_WIRED		0x0020	/* (acgnp) Allocate a wired page */
 #define	VM_ALLOC_ZERO		0x0040	/* (acgnp) Allocate a zeroed page */
@@ -544,7 +543,7 @@
 #define	VM_ALLOC_NOCREAT	0x0400	/* (gp) Don't create a page */
 #define	VM_ALLOC_AVAIL1		0x0800
 #define	VM_ALLOC_IGN_SBUSY	0x1000	/* (gp) Ignore shared busy flag */
-#define	VM_ALLOC_NODUMP		0x2000	/* (ag) don't include in dump */
+#define	VM_ALLOC_NODUMP		0x2000	/* (acgnp) don't include in dump */
 #define	VM_ALLOC_SBUSY		0x4000	/* (acgp) Shared busy the page */
 #define	VM_ALLOC_NOWAIT		0x8000	/* (acgnp) Do not sleep */
 #define	VM_ALLOC_COUNT_MAX	0xffff
Index: sys/vm/vm_page.c
===================================================================
--- sys/vm/vm_page.c
+++ sys/vm/vm_page.c
@@ -4756,12 +4756,11 @@
 /*
  *	vm_page_grab_sleep
  *
- *	Sleep for busy according to VM_ALLOC_ parameters.  Returns true
- *	if the caller should retry and false otherwise.
+ *	Sleep for busy according to VM_ALLOC_ parameters.  Returns true if
+ *	allocflags permits waiting and false otherwise.
  *
- *	If the object is locked on entry the object will be unlocked with
- *	false returns and still locked but possibly having been dropped
- *	with true returns.
+ *	The object may be locked on entry.  If so, its lock will be released and
+ *	reacquired if the routine sleeps.
  */
 static bool
 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex,
@@ -4781,8 +4780,6 @@
 	if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) &&
 	    locked)
 		VM_OBJECT_WLOCK(object);
-	if ((allocflags & VM_ALLOC_WAITFAIL) != 0)
-		return (false);
 
 	return (true);
 }
@@ -4791,18 +4788,23 @@
  * Assert that the grab flags are valid.
  */
 static inline void
-vm_page_grab_check(int allocflags)
+_vm_page_grab_check(int allocflags, const char *func __diagused)
 {
 
 	KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 ||
 	    (allocflags & VM_ALLOC_WIRED) != 0,
-	    ("vm_page_grab*: the pages must be busied or wired"));
+	    ("%s: the pages must be busied or wired", func));
 
 	KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
 	    (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
-	    ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
+	    ("%s: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch", func));
+
+	KASSERT((allocflags & VM_ALLOC_WAITFAIL) == 0,
+	    ("%s: Invalid waitfail flag", func));
 }
 
+#define vm_page_grab_check(...) _vm_page_grab_check(__VA_ARGS__, __func__)
+
 /*
  * Calculate the page allocation flags for grab.
  */
@@ -4812,8 +4814,8 @@
 	int pflags;
 
 	pflags = allocflags &
-	    ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL |
-	    VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY);
+	    ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_NOBUSY |
+	    VM_ALLOC_IGN_SBUSY);
 	if ((allocflags & VM_ALLOC_NOWAIT) == 0)
 		pflags |= VM_ALLOC_WAITFAIL;
 	if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0)
@@ -4855,7 +4857,7 @@
 		return (NULL);
 	m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags));
 	if (m == NULL) {
-		if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0)
+		if ((allocflags & VM_ALLOC_NOWAIT) != 0)
 			return (NULL);
 		goto retrylookup;
 	}
@@ -4954,11 +4956,8 @@
 	vm_page_t ma[VM_INITIAL_PAGEIN];
 	int after, i, pflags, rv;
 
-	KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
-	    (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
-	    ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
-	KASSERT((allocflags &
-	    (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0,
+	vm_page_grab_check(allocflags);
+	KASSERT((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_ZERO)) == 0,
 	    ("vm_page_grab_valid: Invalid flags 0x%X", allocflags));
 	VM_OBJECT_ASSERT_WLOCKED(object);
 	pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY |
@@ -5116,12 +5115,8 @@
 	int flags;
 	int error;
 
-	KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
-	    (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
-	    ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY "
-	    "mismatch"));
-	KASSERT((allocflags &
-	    (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0,
+	vm_page_grab_check(allocflags);
+	KASSERT((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_ZERO)) == 0,
 	    ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags));
 
 	/*
@@ -5218,8 +5213,7 @@
 			m = vm_page_alloc_after(object, pindex + i,
 			    pflags | VM_ALLOC_COUNT(count - i), mpred);
 			if (m == NULL) {
-				if ((allocflags & (VM_ALLOC_NOWAIT |
-				    VM_ALLOC_WAITFAIL)) != 0)
+				if ((allocflags & VM_ALLOC_NOWAIT) != 0)
 					break;
 				goto retrylookup;
 			}