Fix an old-standing bug that crept in along the several revisions:

B_DELWRI cleanup and vnode disassociation should happen just before to
assign the buffer to a queue.

Reported by:	miwi, Volker <volker at vwsoft dot com>,
		Ben Kaduk <minimarmot at gmail dot com>,
		Christopher Mallon <christoph dot mallon at gmx dot de>
Tested by:	lulf, miwi
This commit is contained in:
Attilio Rao 2009-03-17 16:30:49 +00:00
parent a15a45ac9d
commit 76ed3c71f1

View File

@ -1369,9 +1369,23 @@ brelse(struct buf *bp)
if (bp->b_qindex != QUEUE_NONE)
panic("brelse: free buffer onto another queue???");
/*
* If the buffer has junk contents signal it and eventually
* clean up B_DELWRI and diassociate the vnode so that gbincore()
* doesn't find it.
*/
if (bp->b_bufsize == 0 || (bp->b_ioflags & BIO_ERROR) != 0 ||
(bp->b_flags & (B_INVAL | B_NOCACHE | B_RELBUF)) != 0)
bp->b_flags |= B_INVAL;
if (bp->b_flags & B_INVAL) {
if (bp->b_flags & B_DELWRI)
bundirty(bp);
if (bp->b_vp)
brelvp(bp);
}
/* buffers with no memory */
if (bp->b_bufsize == 0) {
bp->b_flags |= B_INVAL;
bp->b_xflags &= ~(BX_BKGRDWRITE | BX_ALTDATA);
if (bp->b_vflags & BV_BKGRDINPROG)
panic("losing buffer 1");
@ -1384,7 +1398,6 @@ brelse(struct buf *bp)
/* buffers with junk contents */
} else if (bp->b_flags & (B_INVAL | B_NOCACHE | B_RELBUF) ||
(bp->b_ioflags & BIO_ERROR)) {
bp->b_flags |= B_INVAL;
bp->b_xflags &= ~(BX_BKGRDWRITE | BX_ALTDATA);
if (bp->b_vflags & BV_BKGRDINPROG)
panic("losing buffer 2");
@ -1406,19 +1419,6 @@ brelse(struct buf *bp)
}
mtx_unlock(&bqlock);
/*
* If B_INVAL and B_DELWRI is set, clear B_DELWRI. We have already
* placed the buffer on the correct queue. We must also disassociate
* the device and vnode for a B_INVAL buffer so gbincore() doesn't
* find it.
*/
if (bp->b_flags & B_INVAL) {
if (bp->b_flags & B_DELWRI)
bundirty(bp);
if (bp->b_vp)
brelvp(bp);
}
/*
* Fixup numfreebuffers count. The bp is on an appropriate queue
* unless locked. We then bump numfreebuffers if it is not B_DELWRI.