git: ff2263469ad0 - main - Revert "vfs_subr: optimize inval_buf_range"

From: Doug Moore <dougm_at_FreeBSD.org>
Date: Thu, 10 Oct 2024 10:46:05 UTC
The branch main has been updated by dougm:

URL: https://cgit.FreeBSD.org/src/commit/?id=ff2263469ad0f304b2e5f44f1a62c9b20c0306a3

commit ff2263469ad0f304b2e5f44f1a62c9b20c0306a3
Author:     Doug Moore <dougm@FreeBSD.org>
AuthorDate: 2024-10-10 10:43:40 +0000
Commit:     Doug Moore <dougm@FreeBSD.org>
CommitDate: 2024-10-10 10:45:43 +0000

    Revert "vfs_subr: optimize inval_buf_range"
    
    @pho has reported that this change leads to a failure of the mmap28.sh
    stress test, and I have confirmed it, so I withdraw it for further
    study.
    
    This reverts commit af4cd5e7b5b50502922b5d2bb42daa7fc66545bb.
---
 sys/kern/vfs_subr.c | 49 ++++++++++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 17 deletions(-)

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 328507efd1fd..f192c6798858 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -2616,24 +2616,17 @@ static int
 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
     daddr_t startlbn, daddr_t endlbn)
 {
-	struct bufv *bv;
 	struct buf *bp, *nbp;
-	uint8_t anyfreed;
-	bool clean;
+	bool anyfreed;
 
 	ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked");
 	ASSERT_BO_LOCKED(bo);
 
-	anyfreed = 1;
-	clean = true;
 	do {
-		bv = clean ? &bo->bo_clean : &bo->bo_dirty;
-		bp = BUF_PCTRIE_LOOKUP_GE(&bv->bv_root, startlbn);
-		if (bp == NULL)
-			continue;
-		TAILQ_FOREACH_FROM_SAFE(bp, &bv->bv_hd, b_bobufs, nbp) {
-			if (bp->b_lblkno >= endlbn)
-				break;
+		anyfreed = false;
+		TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
+			if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn)
+				continue;
 			if (BUF_LOCK(bp,
 			    LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
 			    BO_LOCKPTR(bo)) == ENOLCK) {
@@ -2645,17 +2638,39 @@ v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
 			bp->b_flags |= B_INVAL | B_RELBUF;
 			bp->b_flags &= ~B_ASYNC;
 			brelse(bp);
-			anyfreed = 2;
+			anyfreed = true;
 
 			BO_LOCK(bo);
 			if (nbp != NULL &&
-			    (((nbp->b_xflags &
-			    (clean ? BX_VNCLEAN : BX_VNDIRTY)) == 0) ||
+			    (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
 			    nbp->b_vp != vp ||
-			    (nbp->b_flags & B_DELWRI) == (clean? B_DELWRI: 0)))
+			    (nbp->b_flags & B_DELWRI) != 0))
+				return (EAGAIN);
+		}
+
+		TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
+			if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn)
+				continue;
+			if (BUF_LOCK(bp,
+			    LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
+			    BO_LOCKPTR(bo)) == ENOLCK) {
+				BO_LOCK(bo);
+				return (EAGAIN);
+			}
+			bremfree(bp);
+			bp->b_flags |= B_INVAL | B_RELBUF;
+			bp->b_flags &= ~B_ASYNC;
+			brelse(bp);
+			anyfreed = true;
+
+			BO_LOCK(bo);
+			if (nbp != NULL &&
+			    (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
+			    (nbp->b_vp != vp) ||
+			    (nbp->b_flags & B_DELWRI) == 0))
 				return (EAGAIN);
 		}
-	} while (clean = !clean, anyfreed-- > 0);
+	} while (anyfreed);
 	return (0);
 }