From 6f40eb2413dc2c3e11abe6633bcc5c8517de8637 Mon Sep 17 00:00:00 2001 From: Jan-Simon Pendry Date: Wed, 18 May 1994 02:33:01 -0800 Subject: [PATCH] alter link to do a copyup when possible. open now uses the abstracted copyup. SCCS-vsn: sys/miscfs/union/union_vnops.c 8.13 --- usr/src/sys/miscfs/union/union_vnops.c | 129 ++++++++----------------- 1 file changed, 39 insertions(+), 90 deletions(-) diff --git a/usr/src/sys/miscfs/union/union_vnops.c b/usr/src/sys/miscfs/union/union_vnops.c index ddbf93a204..01fd61a70c 100644 --- a/usr/src/sys/miscfs/union/union_vnops.c +++ b/usr/src/sys/miscfs/union/union_vnops.c @@ -8,7 +8,7 @@ * * %sccs.include.redist.c% * - * @(#)union_vnops.c 8.12 (Berkeley) %G% + * @(#)union_vnops.c 8.13 (Berkeley) %G% */ #include @@ -404,77 +404,7 @@ union_open(ap) */ tvp = un->un_lowervp; if ((ap->a_mode & FWRITE) && (tvp->v_type == VREG)) { - struct vnode *vp; - int i; - - /* - * Open the named file in the upper layer. Note that - * the file may have come into existence *since* the - * lookup was done, since the upper layer may really - * be a loopback mount of some other filesystem... - * so open the file with exclusive create and barf if - * it already exists. - * XXX - perhaps should re-lookup the node (once more - * with feeling) and simply open that. Who knows. - */ - error = union_vn_create(&vp, un, p); - if (error) - return (error); - - /* at this point, uppervp is locked */ - union_newupper(un, vp); - un->un_flags |= UN_ULOCK; - - /* - * Now, if the file is being opened with truncation, - * then the (new) upper vnode is ready to fly, - * otherwise the data from the lower vnode must be - * copied to the upper layer first. This only works - * for regular files (check is made above). - */ - if ((mode & O_TRUNC) == 0) { - /* - * XXX - should not ignore errors - * from VOP_CLOSE - */ - VOP_LOCK(tvp); - error = VOP_OPEN(tvp, FREAD, cred, p); - if (error == 0) { - error = union_copyfile(p, cred, - tvp, un->un_uppervp); - VOP_UNLOCK(tvp); - (void) VOP_CLOSE(tvp, FREAD); - } else { - VOP_UNLOCK(tvp); - } - -#ifdef UNION_DIAGNOSTIC - if (!error) - uprintf("union: copied up %s\n", - un->un_path); -#endif - } - - un->un_flags &= ~UN_ULOCK; - VOP_UNLOCK(un->un_uppervp); - union_vn_close(un->un_uppervp, FWRITE, cred, p); - VOP_LOCK(un->un_uppervp); - un->un_flags |= UN_ULOCK; - - /* - * Subsequent IOs will go to the top layer, so - * call close on the lower vnode and open on the - * upper vnode to ensure that the filesystem keeps - * its references counts right. This doesn't do - * the right thing with (cred) and (FREAD) though. - * Ignoring error returns is not righ, either. - */ - for (i = 0; i < un->un_openl; i++) { - (void) VOP_CLOSE(tvp, FREAD); - (void) VOP_OPEN(un->un_uppervp, FREAD, cred, p); - } - un->un_openl = 0; - + error = union_copyup(un, (mode&O_TRUNC) == 0, cred, p); if (error == 0) error = VOP_OPEN(un->un_uppervp, mode, cred, p); return (error); @@ -919,30 +849,49 @@ union_link(ap) struct componentname *a_cnp; } */ *ap; { - int error; - struct union_node *dun = VTOUNION(ap->a_vp); - struct union_node *un = VTOUNION(ap->a_tdvp); - - if (dun->un_uppervp != NULLVP && un->un_uppervp != NULLVP) { - struct vnode *dvp = dun->un_uppervp; - struct vnode *vp = un->un_uppervp; + int error = 0; + struct union_node *un; + struct vnode *vp; + struct vnode *tdvp; - FIXUP(dun); - VREF(dvp); - dun->un_flags |= UN_KLOCK; - vput(ap->a_vp); + un = VTOUNION(ap->a_vp); - error = VOP_LINK(dvp, vp, ap->a_cnp); + if (ap->a_vp->v_op != ap->a_tdvp->v_op) { + tdvp = ap->a_tdvp; } else { - /* - * XXX: perhaps could copy to upper layer - * and do the link there. - */ - vput(ap->a_vp); + struct union_node *tdun = VTOUNION(ap->a_tdvp); + if (tdun->un_uppervp == NULLVP) { + VOP_LOCK(ap->a_tdvp); + if (un->un_uppervp == tdun->un_dirvp) { + un->un_flags &= ~UN_ULOCK; + VOP_UNLOCK(un->un_uppervp); + } + error = union_copyup(tdun, 1, ap->a_cnp->cn_cred, + ap->a_cnp->cn_proc); + if (un->un_uppervp == tdun->un_dirvp) { + VOP_LOCK(un->un_uppervp); + un->un_flags |= UN_ULOCK; + } + VOP_UNLOCK(ap->a_tdvp); + } + tdvp = tdun->un_uppervp; + } + + vp = un->un_uppervp; + if (vp == NULLVP) error = EROFS; + + if (error) { + vput(ap->a_vp); + return (error); } - return (error); + FIXUP(un); + VREF(vp); + un->un_flags |= UN_KLOCK; + vput(ap->a_vp); + + return (VOP_LINK(vp, tdvp, ap->a_cnp)); } int -- 2.20.1