Use an additional structure to keep information on a set of transfers
initiated by vnd_strategy(). This allows for more natural error handling and solves two bugs: * vnd can disk_unbusy without disk_busy (PR#2657) * b_resid is set correctly on the external at the end of a transfer in case of an error.
This commit is contained in:
pk
parent
2f11ceb63c
commit
740da4fa88
@ -1,4 +1,4 @@
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/* $NetBSD: vnd.c,v 1.35 1997/05/25 16:21:45 pk Exp $ */
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/* $NetBSD: vnd.c,v 1.36 1997/05/25 19:37:36 pk Exp $ */
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/*
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* Copyright (c) 1988 University of Utah.
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@ -95,11 +95,21 @@ int vnddebug = 0x00;
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#define vndunit(x) DISKUNIT(x)
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struct vndbuf {
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struct buf vb_buf;
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struct buf *vb_obp;
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struct vndxfer {
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struct buf *vx_bp; /* Pointer to parent buffer */
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int vx_error;
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int vx_pending; /* # of pending aux buffers */
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};
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struct vndbuf {
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struct buf vb_buf;
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struct vndxfer *vb_xfer;
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};
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#define getvndxfer() \
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((struct vndxfer *)malloc(sizeof(struct vndxfer), M_DEVBUF, M_WAITOK))
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#define putvndxfer(vnx) \
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free((caddr_t)(vnx), M_DEVBUF)
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#define getvndbuf() \
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((struct vndbuf *)malloc(sizeof(struct vndbuf), M_DEVBUF, M_WAITOK))
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#define putvndbuf(vbp) \
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@ -256,6 +266,7 @@ vndstrategy(bp)
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int unit = vndunit(bp->b_dev);
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register struct vnd_softc *vnd = &vnd_softc[unit];
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register struct vndbuf *nbp;
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struct vndxfer *vnx;
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register int bn, bsize, resid;
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register caddr_t addr;
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int sz, flags, error;
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@ -285,6 +296,13 @@ vndstrategy(bp)
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bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize;
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addr = bp->b_data;
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flags = bp->b_flags | B_CALL;
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/* Allocate a header for this transfer and link it to the buffer */
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vnx = getvndxfer();
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vnx->vx_error = 0;
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vnx->vx_pending = 0;
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vnx->vx_bp = bp;
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for (resid = bp->b_resid; resid; resid -= sz) {
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struct vnode *vp;
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daddr_t nbn;
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@ -296,6 +314,27 @@ vndstrategy(bp)
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VOP_UNLOCK(vnd->sc_vp);
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if (error == 0 && (long)nbn == -1)
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error = EIO;
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/*
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* If there was an error or a hole in the file...punt.
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* Note that we may have to wait for any operations
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* that we have already fired off before releasing
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* the buffer.
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*
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* XXX we could deal with holes here but it would be
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* a hassle (in the write case).
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*/
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if (error) {
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vnx->vx_error = error;
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if (vnx->vx_pending == 0) {
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bp->b_error = error;
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bp->b_flags |= B_ERROR;
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putvndxfer(vnx);
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biodone(bp);
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}
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return;
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}
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#ifdef DEBUG
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if (!dovndcluster)
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nra = 0;
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@ -350,25 +389,9 @@ vndstrategy(bp)
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max(0, bp->b_validend - (bp->b_bcount-resid)));
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}
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/* save a reference to the old buffer */
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nbp->vb_obp = bp;
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nbp->vb_xfer = vnx;
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vnx->vx_pending++;
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/*
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* If there was an error or a hole in the file...punt.
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* Note that we deal with this after the nbp allocation.
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* This ensures that we properly clean up any operations
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* that we have already fired off.
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*
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* XXX we could deal with holes here but it would be
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* a hassle (in the write case).
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*/
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if (error) {
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nbp->vb_buf.b_error = error;
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nbp->vb_buf.b_flags |= B_ERROR;
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bp->b_resid -= (resid - sz);
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biodone(&nbp->vb_buf);
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return;
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}
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/*
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* Just sort by block number
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*/
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@ -423,9 +446,10 @@ vndiodone(bp)
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struct buf *bp;
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{
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register struct vndbuf *vbp = (struct vndbuf *) bp;
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register struct buf *pbp = vbp->vb_obp;
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register struct vndxfer *vnx = (struct vndxfer *)vbp->vb_xfer;
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register struct buf *pbp = vnx->vx_bp;
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register struct vnd_softc *vnd = &vnd_softc[vndunit(pbp->b_dev)];
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int s;
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int s, resid;
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s = splbio();
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#ifdef DEBUG
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@ -436,25 +460,39 @@ vndiodone(bp)
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vbp->vb_buf.b_bcount);
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#endif
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resid = vbp->vb_buf.b_bcount - vbp->vb_buf.b_resid;
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pbp->b_resid -= resid;
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disk_unbusy(&vnd->sc_dkdev, resid);
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vnx->vx_pending--;
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if (vbp->vb_buf.b_error) {
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#ifdef DEBUG
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if (vnddebug & VDB_IO)
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printf("vndiodone: vbp %p error %d\n", vbp,
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vbp->vb_buf.b_error);
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#endif
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pbp->b_flags |= B_ERROR;
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pbp->b_error = biowait(&vbp->vb_buf);
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vnx->vx_error = vbp->vb_buf.b_error;
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}
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pbp->b_resid -= vbp->vb_buf.b_bcount;
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putvndbuf(vbp);
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disk_unbusy(&vnd->sc_dkdev, vbp->vb_buf.b_bcount - vbp->vb_buf.b_resid);
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if (pbp->b_resid == 0) {
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/*
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* Wrap up this transaction if it has run to completion or, in
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* case of an error, when all auxiliary buffers have returned.
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*/
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if (pbp->b_resid == 0 || (vnx->vx_error && vnx->vx_pending == 0)) {
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if (vnx->vx_error != 0) {
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pbp->b_flags |= B_ERROR;
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pbp->b_error = vnx->vx_error;
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}
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putvndxfer(vnx);
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#ifdef DEBUG
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if (vnddebug & VDB_IO)
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printf("vndiodone: pbp %p iodone\n", pbp);
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#endif
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biodone(pbp);
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}
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if (vnd->sc_tab.b_actf)
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vndstart(vnd);
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else
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