git: 7b86d14bfccb - stable/14 - unionfs: implement VOP_UNP_* and remove special VSOCK vnode handling
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Date: Sun, 07 Apr 2024 00:31:35 UTC
The branch stable/14 has been updated by jah:
URL: https://cgit.FreeBSD.org/src/commit/?id=7b86d14bfccb589612cbc6b2e54b405da9839232
commit 7b86d14bfccb589612cbc6b2e54b405da9839232
Author: Jason A. Harmening <jah@FreeBSD.org>
AuthorDate: 2024-02-03 17:17:58 +0000
Commit: Jason A. Harmening <jah@FreeBSD.org>
CommitDate: 2024-04-07 00:27:00 +0000
unionfs: implement VOP_UNP_* and remove special VSOCK vnode handling
unionfs has a bunch of clunky special-case code to avoid creating
unionfs wrapper vnodes for AF_UNIX sockets. This was added in 2008
to address PR 118346, but in the intervening years the VOP_UNP_*
operations have been added to provide a clean interface to allow
sockets to work in the presence of stacked filesystems.
PR: 275871
Reviewed by: kib (prior version), olce
Tested by: Karlo Miličević <karlo98.m@gmail.com>
Differential Revision: https://reviews.freebsd.org/D44288
(cherry picked from commit eee6217b40df5877674df1d9aec7d5bd04202876)
---
sys/fs/unionfs/union_vnops.c | 173 +++++++++++++++++++++----------------------
1 file changed, 84 insertions(+), 89 deletions(-)
diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c
index d74d6736e580..5a2d4751ed4f 100644
--- a/sys/fs/unionfs/union_vnops.c
+++ b/sys/fs/unionfs/union_vnops.c
@@ -300,27 +300,8 @@ unionfs_lookup(struct vop_cachedlookup_args *ap)
error = lerror;
if (error != 0)
goto unionfs_lookup_cleanup;
- /*
- * get socket vnode.
- */
- if (uvp != NULLVP && uvp->v_type == VSOCK) {
- vp = uvp;
- vref(vp);
- if (cnp->cn_lkflags & LK_TYPE_MASK)
- vn_lock(vp, cnp->cn_lkflags | LK_RETRY);
- }
- else if (lvp != NULLVP && lvp->v_type == VSOCK) {
- vp = lvp;
- vref(vp);
- if (cnp->cn_lkflags & LK_TYPE_MASK)
- vn_lock(vp, cnp->cn_lkflags | LK_RETRY);
- }
- /*
- * get unionfs vnode.
- */
- else
- error = unionfs_nodeget(dvp->v_mount, uvp, lvp,
- dvp, &vp, cnp);
+ error = unionfs_nodeget(dvp->v_mount, uvp, lvp,
+ dvp, &vp, cnp);
if (error != 0) {
UNIONFSDEBUG(
"unionfs_lookup: Unable to create unionfs vnode.");
@@ -333,7 +314,7 @@ unionfs_lookup(struct vop_cachedlookup_args *ap)
*(ap->a_vpp) = vp;
- if ((cnflags & MAKEENTRY) && vp->v_type != VSOCK)
+ if (cnflags & MAKEENTRY)
cache_enter(dvp, vp, cnp);
unionfs_lookup_cleanup:
@@ -381,9 +362,7 @@ unionfs_create(struct vop_create_args *ap)
lkflags)) && error == 0) {
error = ENOENT;
}
- if (error == 0 && vp->v_type == VSOCK)
- *(ap->a_vpp) = vp;
- else if (error == 0) {
+ if (error == 0) {
VOP_UNLOCK(vp);
error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
ap->a_dvp, ap->a_vpp, cnp);
@@ -464,9 +443,7 @@ unionfs_mknod(struct vop_mknod_args *ap)
lkflags)) && error == 0) {
error = ENOENT;
}
- if (error == 0 && vp->v_type == VSOCK)
- *(ap->a_vpp) = vp;
- else if (error == 0) {
+ if (error == 0) {
VOP_UNLOCK(vp);
error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
ap->a_dvp, ap->a_vpp, cnp);
@@ -1059,9 +1036,7 @@ unionfs_remove(struct vop_remove_args *ap)
struct vnode *udvp;
struct vnode *uvp;
struct vnode *lvp;
- struct vnode *vp;
struct componentname *cnp;
- struct componentname cn;
struct thread *td;
int error;
int pathlen;
@@ -1069,71 +1044,34 @@ unionfs_remove(struct vop_remove_args *ap)
UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
KASSERT_UNIONFS_VNODE(ap->a_dvp);
+ KASSERT_UNIONFS_VNODE(ap->a_vp);
error = 0;
dunp = VTOUNIONFS(ap->a_dvp);
udvp = dunp->un_uppervp;
cnp = ap->a_cnp;
td = curthread;
- unp = NULL;
-
- if (ap->a_vp->v_op != &unionfs_vnodeops) {
- if (ap->a_vp->v_type != VSOCK)
- return (EINVAL);
- ump = NULL;
- vp = uvp = lvp = NULLVP;
- /* search vnode */
- VOP_UNLOCK(ap->a_vp);
- error = unionfs_relookup(udvp, &vp, cnp, &cn, td,
- cnp->cn_nameptr, cnp->cn_namelen, DELETE);
- if (error != 0 && error != ENOENT) {
- vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
- return (error);
- }
- if (error == 0 && vp == ap->a_vp) {
- /* target vnode in upper */
- uvp = vp;
- vrele(vp);
- } else {
- /* target vnode in lower */
- if (vp != NULLVP) {
- if (udvp == vp)
- vrele(vp);
- else
- vput(vp);
- }
- vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
- lvp = ap->a_vp;
- }
- path = cnp->cn_nameptr;
- pathlen = cnp->cn_namelen;
- } else {
- ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
- unp = VTOUNIONFS(ap->a_vp);
- uvp = unp->un_uppervp;
- lvp = unp->un_lowervp;
- path = unp->un_path;
- pathlen = unp->un_pathlen;
- }
+ ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
+ unp = VTOUNIONFS(ap->a_vp);
+ uvp = unp->un_uppervp;
+ lvp = unp->un_lowervp;
+ path = unp->un_path;
+ pathlen = unp->un_pathlen;
if (udvp == NULLVP)
return (EROFS);
if (uvp != NULLVP) {
- /*
- * XXX: if the vnode type is VSOCK, it will create whiteout
- * after remove.
- */
int udvp_lkflags, uvp_lkflags;
if (ump == NULL || ump->um_whitemode == UNIONFS_WHITE_ALWAYS ||
lvp != NULLVP)
cnp->cn_flags |= DOWHITEOUT;
unionfs_forward_vop_start_pair(udvp, &udvp_lkflags,
- ((unp == NULL) ? NULL : uvp), &uvp_lkflags);
+ uvp, &uvp_lkflags);
error = VOP_REMOVE(udvp, uvp, cnp);
unionfs_forward_vop_finish_pair(ap->a_dvp, udvp, udvp_lkflags,
- ((unp == NULL) ? NULL : ap->a_vp), uvp, uvp_lkflags);
+ ap->a_vp, uvp, uvp_lkflags);
} else if (lvp != NULLVP)
error = unionfs_mkwhiteout(ap->a_dvp, udvp, cnp, td, path, pathlen);
@@ -1171,22 +1109,18 @@ unionfs_link(struct vop_link_args *ap)
if (udvp == NULLVP)
return (EROFS);
- if (ap->a_vp->v_op != &unionfs_vnodeops)
- uvp = ap->a_vp;
- else {
- unp = VTOUNIONFS(ap->a_vp);
+ unp = VTOUNIONFS(ap->a_vp);
- if (unp->un_uppervp == NULLVP) {
- if (ap->a_vp->v_type != VREG)
- return (EOPNOTSUPP);
+ if (unp->un_uppervp == NULLVP) {
+ if (ap->a_vp->v_type != VREG)
+ return (EOPNOTSUPP);
- error = unionfs_copyfile(unp, 1, cnp->cn_cred, td);
- if (error != 0)
- return (error);
- needrelookup = 1;
- }
- uvp = unp->un_uppervp;
+ error = unionfs_copyfile(unp, 1, cnp->cn_cred, td);
+ if (error != 0)
+ return (error);
+ needrelookup = 1;
}
+ uvp = unp->un_uppervp;
if (needrelookup != 0)
error = unionfs_relookup_for_create(ap->a_tdvp, cnp, td);
@@ -2835,6 +2769,64 @@ unionfs_unset_text(struct vop_unset_text_args *ap)
return (0);
}
+static int
+unionfs_unp_bind(struct vop_unp_bind_args *ap)
+{
+ struct vnode *tvp;
+ struct unionfs_node *unp;
+
+ ASSERT_VOP_LOCKED(ap->a_vp, __func__);
+ unp = VTOUNIONFS(ap->a_vp);
+ tvp = unp->un_uppervp != NULL ? unp->un_uppervp : unp->un_lowervp;
+ VOP_UNP_BIND(tvp, ap->a_unpcb);
+ return (0);
+}
+
+static int
+unionfs_unp_connect(struct vop_unp_connect_args *ap)
+{
+ struct vnode *tvp;
+ struct unionfs_node *unp;
+
+ ASSERT_VOP_LOCKED(ap->a_vp, __func__);
+ unp = VTOUNIONFS(ap->a_vp);
+ tvp = unp->un_uppervp != NULL ? unp->un_uppervp : unp->un_lowervp;
+ VOP_UNP_CONNECT(tvp, ap->a_unpcb);
+ return (0);
+}
+
+static int
+unionfs_unp_detach(struct vop_unp_detach_args *ap)
+{
+ struct vnode *tvp;
+ struct unionfs_node *unp;
+
+ tvp = NULL;
+ /*
+ * VOP_UNP_DETACH() is not guaranteed to be called with the unionfs
+ * vnode locked, so we take the interlock to prevent a concurrent
+ * unmount from freeing the unionfs private data.
+ */
+ VI_LOCK(ap->a_vp);
+ unp = VTOUNIONFS(ap->a_vp);
+ if (unp != NULL) {
+ tvp = unp->un_uppervp != NULL ?
+ unp->un_uppervp : unp->un_lowervp;
+ /*
+ * Hold the target vnode to prevent a concurrent unionfs
+ * unmount from causing it to be recycled once the interlock
+ * is dropped.
+ */
+ vholdnz(tvp);
+ }
+ VI_UNLOCK(ap->a_vp);
+ if (tvp != NULL) {
+ VOP_UNP_DETACH(tvp);
+ vdrop(tvp);
+ }
+ return (0);
+}
+
struct vop_vector unionfs_vnodeops = {
.vop_default = &default_vnodeops,
@@ -2888,5 +2880,8 @@ struct vop_vector unionfs_vnodeops = {
.vop_vput_pair = unionfs_vput_pair,
.vop_set_text = unionfs_set_text,
.vop_unset_text = unionfs_unset_text,
+ .vop_unp_bind = unionfs_unp_bind,
+ .vop_unp_connect = unionfs_unp_connect,
+ .vop_unp_detach = unionfs_unp_detach,
};
VFS_VOP_VECTOR_REGISTER(unionfs_vnodeops);