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author | trociny <trociny@FreeBSD.org> | 2012-02-25 10:15:41 +0000 |
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committer | trociny <trociny@FreeBSD.org> | 2012-02-25 10:15:41 +0000 |
commit | 87f7f0cfe8d3d17bc154ca2c0dcd51bca1444006 (patch) | |
tree | 8d321a0d4dfa05d863db2db15721bdb62ad66f41 /sys/kern/uipc_usrreq.c | |
parent | 1227707e5566e30c536ae473402e3c3445c746c1 (diff) | |
download | FreeBSD-src-87f7f0cfe8d3d17bc154ca2c0dcd51bca1444006.zip FreeBSD-src-87f7f0cfe8d3d17bc154ca2c0dcd51bca1444006.tar.gz |
When detaching an unix domain socket, uipc_detach() checks
unp->unp_vnode pointer to detect if there is a vnode associated with
(binded to) this socket and does necessary cleanup if there is.
The issue is that after forced unmount this check may be too late as
the unp_vnode is reclaimed and the reference is stale.
To fix this provide a helper function that is called on a socket vnode
reclamation to do necessary cleanup.
Pointed by: kib
Reviewed by: kib
MFC after: 2 weeks
Diffstat (limited to 'sys/kern/uipc_usrreq.c')
-rw-r--r-- | sys/kern/uipc_usrreq.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c index 33365ee..8f329fd 100644 --- a/sys/kern/uipc_usrreq.c +++ b/sys/kern/uipc_usrreq.c @@ -2300,6 +2300,45 @@ unp_scan(struct mbuf *m0, void (*op)(struct file *)) } } +/* + * A helper function called by VFS before socket-type vnode reclamation. + * For an active vnode it clears unp_vnode pointer and decrements unp_vnode + * use count. + */ +void +vfs_unp_reclaim(struct vnode *vp) +{ + struct socket *so; + struct unpcb *unp; + int active; + + ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); + KASSERT(vp->v_type == VSOCK, + ("vfs_unp_reclaim: vp->v_type != VSOCK")); + + active = 0; + UNP_LINK_WLOCK(); + so = vp->v_socket; + if (so == NULL) + goto done; + unp = sotounpcb(so); + if (unp == NULL) + goto done; + UNP_PCB_LOCK(unp); + if (unp->unp_vnode != NULL) { + KASSERT(unp->unp_vnode == vp, + ("vfs_unp_reclaim: vp != unp->unp_vnode")); + vp->v_socket = NULL; + unp->unp_vnode = NULL; + active = 1; + } + UNP_PCB_UNLOCK(unp); +done: + UNP_LINK_WUNLOCK(); + if (active) + vunref(vp); +} + #ifdef DDB static void db_print_indent(int indent) |