Fix LOR between vnode lock and internal mqueue locks.
This commit is contained in:
David Xu
parent
7fa1f32a7e
commit
fbc48e974e
@ -373,16 +373,24 @@ mqnode_addref(struct mqfs_node *node)
|
||||
static __inline void
|
||||
mqnode_release(struct mqfs_node *node)
|
||||
{
|
||||
struct mqfs_info *mqfs;
|
||||
int old, exp;
|
||||
|
||||
mqfs = node->mn_info;
|
||||
old = atomic_fetchadd_int(&node->mn_refcount, -1);
|
||||
if (node->mn_type == mqfstype_dir ||
|
||||
node->mn_type == mqfstype_root)
|
||||
exp = 3; /* include . and .. */
|
||||
else
|
||||
exp = 1;
|
||||
if (old == exp)
|
||||
if (old == exp) {
|
||||
int locked = sx_xlocked(&mqfs->mi_lock);
|
||||
if (!locked)
|
||||
sx_xlock(&mqfs->mi_lock);
|
||||
mqfs_destroy(node);
|
||||
if (!locked)
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
@ -417,7 +425,7 @@ mqfs_create_node(const char *name, int namelen, struct ucred *cred, int mode,
|
||||
strncpy(node->mn_name, name, namelen);
|
||||
node->mn_type = nodetype;
|
||||
node->mn_refcount = 1;
|
||||
getnanotime(&node->mn_birth);
|
||||
vfs_timestamp(&node->mn_birth);
|
||||
node->mn_ctime = node->mn_atime = node->mn_mtime
|
||||
= node->mn_birth;
|
||||
node->mn_uid = cred->cr_uid;
|
||||
@ -601,9 +609,7 @@ mqfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
|
||||
int ret;
|
||||
|
||||
mqfs = VFSTOMQFS(mp);
|
||||
sx_xlock(&mqfs->mi_lock);
|
||||
ret = mqfs_allocv(mp, vpp, mqfs->mi_root);
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
return (ret);
|
||||
}
|
||||
|
||||
@ -696,28 +702,56 @@ static int
|
||||
mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn)
|
||||
{
|
||||
struct mqfs_vdata *vd;
|
||||
struct mqfs_info *mqfs;
|
||||
struct vnode *newvpp;
|
||||
int error;
|
||||
|
||||
mqfs = pn->mn_info;
|
||||
*vpp = NULL;
|
||||
sx_xlock(&mqfs->mi_lock);
|
||||
LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
|
||||
if (vd->mv_vnode->v_mount == mp)
|
||||
if (vd->mv_vnode->v_mount == mp) {
|
||||
vhold(vd->mv_vnode);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (vd != NULL) {
|
||||
found:
|
||||
*vpp = vd->mv_vnode;
|
||||
vget(*vpp, LK_RETRY | LK_EXCLUSIVE, curthread);
|
||||
return (0);
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
error = vget(*vpp, LK_RETRY | LK_EXCLUSIVE, curthread);
|
||||
vdrop(*vpp);
|
||||
return (error);
|
||||
}
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
|
||||
error = getnewvnode("mqueue", mp, &mqfs_vnodeops, vpp);
|
||||
error = getnewvnode("mqueue", mp, &mqfs_vnodeops, &newvpp);
|
||||
if (error)
|
||||
return (error);
|
||||
vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY);
|
||||
error = insmntque(*vpp, mp);
|
||||
if (error != 0) {
|
||||
*vpp = NULLVP;
|
||||
vn_lock(newvpp, LK_EXCLUSIVE | LK_RETRY);
|
||||
error = insmntque(newvpp, mp);
|
||||
if (error != 0)
|
||||
return (error);
|
||||
|
||||
sx_xlock(&mqfs->mi_lock);
|
||||
/*
|
||||
* Check if it has already been allocated
|
||||
* while we were blocked.
|
||||
*/
|
||||
LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
|
||||
if (vd->mv_vnode->v_mount == mp) {
|
||||
vhold(vd->mv_vnode);
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
|
||||
vgone(newvpp);
|
||||
vput(newvpp);
|
||||
goto found;
|
||||
}
|
||||
}
|
||||
|
||||
*vpp = newvpp;
|
||||
|
||||
vd = uma_zalloc(mvdata_zone, M_WAITOK);
|
||||
(*vpp)->v_data = vd;
|
||||
vd->mv_vnode = *vpp;
|
||||
@ -745,6 +779,7 @@ mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn)
|
||||
default:
|
||||
panic("%s has unexpected type: %d", pn->mn_name, pn->mn_type);
|
||||
}
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
return (0);
|
||||
}
|
||||
|
||||
@ -756,6 +791,7 @@ mqfs_search(struct mqfs_node *pd, const char *name, int len)
|
||||
{
|
||||
struct mqfs_node *pn;
|
||||
|
||||
sx_assert(&pd->mn_info->mi_lock, SX_LOCKED);
|
||||
LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
|
||||
if (strncmp(pn->mn_name, name, len) == 0)
|
||||
return (pn);
|
||||
@ -773,6 +809,7 @@ mqfs_lookupx(struct vop_cachedlookup_args *ap)
|
||||
struct vnode *dvp, **vpp;
|
||||
struct mqfs_node *pd;
|
||||
struct mqfs_node *pn;
|
||||
struct mqfs_info *mqfs;
|
||||
int nameiop, flags, error, namelen;
|
||||
char *pname;
|
||||
struct thread *td;
|
||||
@ -787,6 +824,7 @@ mqfs_lookupx(struct vop_cachedlookup_args *ap)
|
||||
nameiop = cnp->cn_nameiop;
|
||||
pd = VTON(dvp);
|
||||
pn = NULL;
|
||||
mqfs = pd->mn_info;
|
||||
*vpp = NULLVP;
|
||||
|
||||
if (dvp->v_type != VDIR)
|
||||
@ -825,24 +863,32 @@ mqfs_lookupx(struct vop_cachedlookup_args *ap)
|
||||
}
|
||||
|
||||
/* named node */
|
||||
sx_xlock(&mqfs->mi_lock);
|
||||
pn = mqfs_search(pd, pname, namelen);
|
||||
if (pn != NULL)
|
||||
mqnode_addref(pn);
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
|
||||
/* found */
|
||||
if (pn != NULL) {
|
||||
/* DELETE */
|
||||
if (nameiop == DELETE && (flags & ISLASTCN)) {
|
||||
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
|
||||
if (error)
|
||||
if (error) {
|
||||
mqnode_release(pn);
|
||||
return (error);
|
||||
}
|
||||
if (*vpp == dvp) {
|
||||
VREF(dvp);
|
||||
*vpp = dvp;
|
||||
mqnode_release(pn);
|
||||
return (0);
|
||||
}
|
||||
}
|
||||
|
||||
/* allocate vnode */
|
||||
error = mqfs_allocv(dvp->v_mount, vpp, pn);
|
||||
mqnode_release(pn);
|
||||
if (error == 0 && cnp->cn_flags & MAKEENTRY)
|
||||
cache_enter(dvp, *vpp, cnp);
|
||||
return (error);
|
||||
@ -877,12 +923,9 @@ struct vop_lookup_args {
|
||||
static int
|
||||
mqfs_lookup(struct vop_cachedlookup_args *ap)
|
||||
{
|
||||
struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
|
||||
int rc;
|
||||
|
||||
sx_xlock(&mqfs->mi_lock);
|
||||
rc = mqfs_lookupx(ap);
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
return (rc);
|
||||
}
|
||||
|
||||
@ -915,30 +958,23 @@ mqfs_create(struct vop_create_args *ap)
|
||||
if (mq == NULL)
|
||||
return (EAGAIN);
|
||||
sx_xlock(&mqfs->mi_lock);
|
||||
#if 0
|
||||
/* named node */
|
||||
pn = mqfs_search(pd, cnp->cn_nameptr, cnp->cn_namelen);
|
||||
if (pn != NULL) {
|
||||
mqueue_free(mq);
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
return (EEXIST);
|
||||
}
|
||||
#else
|
||||
if ((cnp->cn_flags & HASBUF) == 0)
|
||||
panic("%s: no name", __func__);
|
||||
#endif
|
||||
pn = mqfs_create_file(pd, cnp->cn_nameptr, cnp->cn_namelen,
|
||||
cnp->cn_cred, ap->a_vap->va_mode);
|
||||
if (pn == NULL)
|
||||
if (pn == NULL) {
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
error = ENOSPC;
|
||||
else {
|
||||
} else {
|
||||
mqnode_addref(pn);
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
|
||||
mqnode_release(pn);
|
||||
if (error)
|
||||
mqfs_destroy(pn);
|
||||
else
|
||||
pn->mn_data = mq;
|
||||
}
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
if (error)
|
||||
mqueue_free(mq);
|
||||
return (error);
|
||||
@ -1412,24 +1448,19 @@ mqfs_mkdir(struct vop_mkdir_args *ap)
|
||||
if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
|
||||
return (ENOTDIR);
|
||||
sx_xlock(&mqfs->mi_lock);
|
||||
#if 0
|
||||
/* named node */
|
||||
pn = mqfs_search(pd, cnp->cn_nameptr, cnp->cn_namelen);
|
||||
if (pn != NULL) {
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
return (EEXIST);
|
||||
}
|
||||
#else
|
||||
if ((cnp->cn_flags & HASBUF) == 0)
|
||||
panic("%s: no name", __func__);
|
||||
#endif
|
||||
pn = mqfs_create_dir(pd, cnp->cn_nameptr, cnp->cn_namelen,
|
||||
ap->a_vap->cn_cred, ap->a_vap->va_mode);
|
||||
if (pn == NULL)
|
||||
error = ENOSPC;
|
||||
else
|
||||
error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
|
||||
if (pn != NULL)
|
||||
mqnode_addref(pn);
|
||||
sx_xunlock(&mqfs->mi_lock);
|
||||
if (pn == NULL) {
|
||||
error = ENOSPC;
|
||||
} else {
|
||||
error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
|
||||
mqnode_release(pn);
|
||||
}
|
||||
return (error);
|
||||
}
|
||||
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user