MFC r284887:

Handle errors from background write of the cylinder group blocks.

MFC r284927:
Simplify code.

Approved by:	re (gjb)

1 files changed, 18 insertions, 1 deletions

diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 53d85bd..26c0286 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -1977,12 +1977,19 @@ ffs_backgroundwritedone(struct buf *bp)
 	BO_LOCK(bufobj);
 	if ((origbp = gbincore(bp->b_bufobj, bp->b_lblkno)) == NULL)
 		panic("backgroundwritedone: lost buffer");
+
+	/*
+	 * We should mark the cylinder group buffer origbp as
+	 * dirty, to not loose the failed write.
+	 */
+	if ((bp->b_ioflags & BIO_ERROR) != 0)
+		origbp->b_vflags |= BV_BKGRDERR;
 	BO_UNLOCK(bufobj);
 	/*
 	 * Process dependencies then return any unfinished ones.
 	 */
 	pbrelvp(bp);
-	if (!LIST_EMPTY(&bp->b_dep))
+	if (!LIST_EMPTY(&bp->b_dep) && (bp->b_ioflags & BIO_ERROR) == 0)
 		buf_complete(bp);
 #ifdef SOFTUPDATES
 	if (!LIST_EMPTY(&bp->b_dep))
@@ -1994,6 +2001,15 @@ ffs_backgroundwritedone(struct buf *bp)
 	 */
 	bp->b_flags |= B_NOCACHE;
 	bp->b_flags &= ~B_CACHE;
+
+	/*
+	 * Prevent brelse() from trying to keep and re-dirtying bp on
+	 * errors. It causes b_bufobj dereference in
+	 * bdirty()/reassignbuf(), and b_bufobj was cleared in
+	 * pbrelvp() above.
+	 */
+	if ((bp->b_ioflags & BIO_ERROR) != 0)
+		bp->b_flags |= B_INVAL;
 	bufdone(bp);
 	BO_LOCK(bufobj);
 	/*
@@ -2055,6 +2071,7 @@ ffs_bufwrite(struct buf *bp)
 		if (bp->b_vflags & BV_BKGRDINPROG)
 			panic("bufwrite: still writing");
 	}
+	bp->b_vflags &= ~BV_BKGRDERR;
 	BO_UNLOCK(bp->b_bufobj);
 
 	/*