Remove the support for using non-mpsafe filesystem modules.

In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.

The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.

Conducted and reviewed by:	attilio
Tested by:	pho

1 files changed, 5 insertions, 24 deletions

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index 626847c..0480bd4 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -266,14 +266,13 @@ static struct mtx nblock;
 /*
  * Definitions for the buffer free lists.
  */
-#define BUFFER_QUEUES	6	/* number of free buffer queues */
+#define BUFFER_QUEUES	5	/* number of free buffer queues */
 
 #define QUEUE_NONE	0	/* on no queue */
 #define QUEUE_CLEAN	1	/* non-B_DELWRI buffers */
 #define QUEUE_DIRTY	2	/* B_DELWRI buffers */
-#define QUEUE_DIRTY_GIANT 3	/* B_DELWRI buffers that need giant */
-#define QUEUE_EMPTYKVA	4	/* empty buffer headers w/KVA assignment */
-#define QUEUE_EMPTY	5	/* empty buffer headers */
+#define QUEUE_EMPTYKVA	3	/* empty buffer headers w/KVA assignment */
+#define QUEUE_EMPTY	4	/* empty buffer headers */
 #define QUEUE_SENTINEL	1024	/* not an queue index, but mark for sentinel */
 
 /* Queues for free buffers with various properties */
@@ -1461,10 +1460,7 @@ brelse(struct buf *bp)
 		TAILQ_INSERT_HEAD(&bufqueues[QUEUE_CLEAN], bp, b_freelist);
 	/* remaining buffers */
 	} else {
-		if ((bp->b_flags & (B_DELWRI|B_NEEDSGIANT)) ==
-		    (B_DELWRI|B_NEEDSGIANT))
-			bp->b_qindex = QUEUE_DIRTY_GIANT;
-		else if (bp->b_flags & B_DELWRI)
+		if (bp->b_flags & B_DELWRI)
 			bp->b_qindex = QUEUE_DIRTY;
 		else
 			bp->b_qindex = QUEUE_CLEAN;
@@ -1561,10 +1557,7 @@ bqrelse(struct buf *bp)
 		panic("bqrelse: free buffer onto another queue???");
 	/* buffers with stale but valid contents */
 	if (bp->b_flags & B_DELWRI) {
-		if (bp->b_flags & B_NEEDSGIANT)
-			bp->b_qindex = QUEUE_DIRTY_GIANT;
-		else
-			bp->b_qindex = QUEUE_DIRTY;
+		bp->b_qindex = QUEUE_DIRTY;
 		TAILQ_INSERT_TAIL(&bufqueues[bp->b_qindex], bp, b_freelist);
 	} else {
 		/*
@@ -2170,12 +2163,6 @@ buf_do_flush(struct vnode *vp)
 	int flushed;
 
 	flushed = flushbufqueues(vp, QUEUE_DIRTY, 0);
-	/* The list empty check here is slightly racy */
-	if (!TAILQ_EMPTY(&bufqueues[QUEUE_DIRTY_GIANT])) {
-		mtx_lock(&Giant);
-		flushed += flushbufqueues(vp, QUEUE_DIRTY_GIANT, 0);
-		mtx_unlock(&Giant);
-	}
 	if (flushed == 0) {
 		/*
 		 * Could not find any buffers without rollback
@@ -2183,12 +2170,6 @@ buf_do_flush(struct vnode *vp)
 		 * in the hopes of eventually making progress.
 		 */
 		flushbufqueues(vp, QUEUE_DIRTY, 1);
-		if (!TAILQ_EMPTY(
-			    &bufqueues[QUEUE_DIRTY_GIANT])) {
-			mtx_lock(&Giant);
-			flushbufqueues(vp, QUEUE_DIRTY_GIANT, 1);
-			mtx_unlock(&Giant);
-		}
 	}
 	return (flushed);
 }