14127f5b21
crash.sh script attached to FreeNAS bug 4109: https://bugs.freenas.org/issues/4109 Three are in the snapshot layer: a) AVG explains in his notes: https://wiki.freebsd.org/AvgVfsSolarisVsFreeBSD "VOP_INACTIVE must not do any destructive actions to a vnode and its filesystem node, nor invalidate them in any way." gfs_vop_inactive and zfsctl_snapshot_inactive did just that. In OpenSolaris VOP_INACTIVE is much closer to FreeBSD's VOP_RECLAIM. Rename & move them to gfs_vop_reclaim and zfsctl_snapshot_reclaim and merge in the requisite vnode_destroy from zfsctl_common_reclaim. b) gfs_lookup_dot and various zfsctl functions do not honor the FreeBSD VFS convention of only locking from the root downward. When looking up ".." the convention is to drop the current leaf vnode lock before acquiring the directory vnode and then subsequently re-acquiring the lock on the leaf vnode. This fixes that in all the places that our exercised by crash.sh. c) The snapshot may already be unmounted when the directory vnode is reclaimed. Check for this case and return. One in the common layer: d) Callers of traverse expect the reference to the vnode passed in to be maintained. Don't release it. This last one may be an unclear contract. There may in fact be some callers that do expect the reference to be dropped on success in addition to callers that expect it to be released. In this case a further audit of the callers is needed and a consensus on the correct behavior. PR: 184677 Submitted by: kmacy Reviewed by: delphij, will, avg MFC after: 2 weeks Sponsored by: iXsystems
116 lines
3.2 KiB
C
116 lines
3.2 KiB
C
/*-
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* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/systm.h>
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#include <sys/pathname.h>
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#include <sys/vfs.h>
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#include <sys/vnode.h>
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int
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lookupname(char *dirname, enum uio_seg seg, enum symfollow follow,
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vnode_t **dirvpp, vnode_t **compvpp)
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{
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return (lookupnameat(dirname, seg, follow, dirvpp, compvpp, NULL));
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}
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int
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lookupnameat(char *dirname, enum uio_seg seg, enum symfollow follow,
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vnode_t **dirvpp, vnode_t **compvpp, vnode_t *startvp)
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{
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struct nameidata nd;
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int error, ltype;
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ASSERT(dirvpp == NULL);
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vref(startvp);
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ltype = VOP_ISLOCKED(startvp);
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VOP_UNLOCK(startvp, 0);
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NDINIT_ATVP(&nd, LOOKUP, LOCKLEAF | follow, seg, dirname,
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startvp, curthread);
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error = namei(&nd);
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*compvpp = nd.ni_vp;
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NDFREE(&nd, NDF_ONLY_PNBUF);
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vn_lock(startvp, ltype | LK_RETRY);
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return (error);
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}
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int
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traverse(vnode_t **cvpp, int lktype)
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{
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vnode_t *cvp;
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vnode_t *tvp;
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vfs_t *vfsp;
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int error;
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cvp = *cvpp;
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tvp = NULL;
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/*
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* If this vnode is mounted on, then we transparently indirect
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* to the vnode which is the root of the mounted file system.
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* Before we do this we must check that an unmount is not in
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* progress on this vnode.
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*/
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for (;;) {
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/*
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* Reached the end of the mount chain?
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*/
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vfsp = vn_mountedvfs(cvp);
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if (vfsp == NULL)
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break;
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error = vfs_busy(vfsp, 0);
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/*
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* tvp is NULL for *cvpp vnode, which we can't unlock.
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* At least some callers expect the reference to be
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* maintained to the original *cvpp
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*/
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if (tvp != NULL)
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vput(cvp);
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if (error)
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return (error);
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/*
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* The read lock must be held across the call to VFS_ROOT() to
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* prevent a concurrent unmount from destroying the vfs.
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*/
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error = VFS_ROOT(vfsp, lktype, &tvp);
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vfs_unbusy(vfsp);
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if (error != 0)
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return (error);
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cvp = tvp;
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}
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*cvpp = cvp;
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return (0);
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}
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