Start playing around with vnode locks. For now, do the very easy
thing and release locks before the userspace wait for operations which release the lock before exit from the method in any case. However, releasing the lock after inserting the request on the operation queue gives us proper ordering possibilities in userspace (at least if that bit were implemented, but I don't think there any file system in userspace that depends on kernel locking and probably there never should be one). inspired by a conversation with Nacho Navarro
This commit is contained in:
pooka
parent
2632ba6df4
commit
63e9f065b3
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@ -1,4 +1,4 @@
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/* $NetBSD: puffs_vnops.c,v 1.115 2007/11/17 18:09:04 pooka Exp $ */
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/* $NetBSD: puffs_vnops.c,v 1.116 2007/11/17 21:30:48 pooka Exp $ */
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/*
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* Copyright (c) 2005, 2006, 2007 Antti Kantee. All Rights Reserved.
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@ -30,7 +30,7 @@
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: puffs_vnops.c,v 1.115 2007/11/17 18:09:04 pooka Exp $");
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__KERNEL_RCSID(0, "$NetBSD: puffs_vnops.c,v 1.116 2007/11/17 21:30:48 pooka Exp $");
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#include <sys/param.h>
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#include <sys/fstrans.h>
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@ -437,6 +437,20 @@ puffs_abortbutton(struct puffs_mount *pmp, int what,
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puffs_callreclaim(pmp, cookie, cnp->cn_lwp);
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}
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/*
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* Begin vnode operations.
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*
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* A word from the keymaster about locks: generally we don't want
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* to use the vnode locks at all: it creates an ugly dependency between
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* the userlandia file server and the kernel. But we'll play along with
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* the kernel vnode locks for now. However, even currently we attempt
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* to release locks as early as possible. This is possible for some
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* operations which a) don't need a locked vnode after the userspace op
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* and b) return with the vnode unlocked. Theoretically we could
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* unlock-do op-lock for others and order the graph in userspace, but I
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* don't want to think of the consequences for the time being.
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*/
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int
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puffs_lookup(void *v)
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{
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@ -581,6 +595,27 @@ puffs_lookup(void *v)
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return error;
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}
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#define REFPN_AND_UNLOCKVP(a, b) \
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do { \
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mutex_enter(&b->pn_mtx); \
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puffs_referencenode(b); \
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mutex_exit(&b->pn_mtx); \
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VOP_UNLOCK(a, 0); \
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} while (/*CONSTCOND*/0)
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#define REFPN(b) \
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do { \
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mutex_enter(&b->pn_mtx); \
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puffs_referencenode(b); \
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mutex_exit(&b->pn_mtx); \
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} while (/*CONSTCOND*/0)
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#define RELEPN_AND_VP(a, b) \
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do { \
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puffs_releasenode(b); \
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vrele(a); \
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} while (/*CONSTCOND*/0)
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int
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puffs_create(void *v)
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{
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@ -593,8 +628,10 @@ puffs_create(void *v)
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} */ *ap = v;
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PUFFS_MSG_VARS(vn, create);
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struct vnode *dvp = ap->a_dvp;
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struct puffs_node *dpn = VPTOPP(dvp);
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struct componentname *cnp = ap->a_cnp;
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struct puffs_mount *pmp = MPTOPUFFSMP(dvp->v_mount);
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struct mount *mp = dvp->v_mount;
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struct puffs_mount *pmp = MPTOPUFFSMP(mp);
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int error;
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DPRINTF(("puffs_create: dvp %p, cnp: %s\n",
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@ -607,22 +644,31 @@ puffs_create(void *v)
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puffs_msg_setinfo(park_create, PUFFSOP_VN,
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PUFFS_VN_CREATE, VPTOPNC(dvp));
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PUFFS_MSG_ENQUEUEWAIT2(pmp, park_create, dvp->v_data, NULL, error);
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/*
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* Do the dance:
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* + insert into queue ("interlock")
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* + unlock vnode
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* + wait for response
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*/
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puffs_msg_enqueue(pmp, park_create);
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REFPN_AND_UNLOCKVP(dvp, dpn);
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error = puffs_msg_wait2(pmp, park_create, dpn, NULL);
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error = checkerr(pmp, error, __func__);
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if (error)
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goto out;
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error = puffs_newnode(dvp->v_mount, dvp, ap->a_vpp,
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error = puffs_newnode(mp, dvp, ap->a_vpp,
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create_msg->pvnr_newnode, cnp, ap->a_vap->va_type, 0);
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if (error)
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puffs_abortbutton(pmp, PUFFS_ABORT_CREATE, VPTOPNC(dvp),
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puffs_abortbutton(pmp, PUFFS_ABORT_CREATE, dpn->pn_cookie,
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create_msg->pvnr_newnode, cnp);
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out:
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if (error || (cnp->cn_flags & SAVESTART) == 0)
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PNBUF_PUT(cnp->cn_pnbuf);
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vput(dvp);
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RELEPN_AND_VP(dvp, dpn);
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DPRINTF(("puffs_create: return %d\n", error));
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PUFFS_MSG_RELEASE(create);
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return error;
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@ -640,8 +686,10 @@ puffs_mknod(void *v)
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} */ *ap = v;
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PUFFS_MSG_VARS(vn, mknod);
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struct vnode *dvp = ap->a_dvp;
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struct puffs_node *dpn = VPTOPP(dvp);
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struct componentname *cnp = ap->a_cnp;
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struct puffs_mount *pmp = MPTOPUFFSMP(dvp->v_mount);
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struct mount *mp = dvp->v_mount;
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struct puffs_mount *pmp = MPTOPUFFSMP(mp);
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int error;
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PUFFS_MSG_ALLOC(vn, mknod);
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@ -651,23 +699,26 @@ puffs_mknod(void *v)
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puffs_msg_setinfo(park_mknod, PUFFSOP_VN,
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PUFFS_VN_MKNOD, VPTOPNC(dvp));
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PUFFS_MSG_ENQUEUEWAIT2(pmp, park_mknod, dvp->v_data, NULL, error);
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puffs_msg_enqueue(pmp, park_mknod);
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REFPN_AND_UNLOCKVP(dvp, dpn);
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error = puffs_msg_wait2(pmp, park_mknod, dpn, NULL);
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error = checkerr(pmp, error, __func__);
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if (error)
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goto out;
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error = puffs_newnode(dvp->v_mount, dvp, ap->a_vpp,
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error = puffs_newnode(mp, dvp, ap->a_vpp,
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mknod_msg->pvnr_newnode, cnp, ap->a_vap->va_type,
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ap->a_vap->va_rdev);
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if (error)
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puffs_abortbutton(pmp, PUFFS_ABORT_MKNOD, VPTOPNC(dvp),
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puffs_abortbutton(pmp, PUFFS_ABORT_MKNOD, dpn->pn_cookie,
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mknod_msg->pvnr_newnode, cnp);
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out:
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PUFFS_MSG_RELEASE(mknod);
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if (error || (cnp->cn_flags & SAVESTART) == 0)
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PNBUF_PUT(cnp->cn_pnbuf);
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vput(dvp);
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RELEPN_AND_VP(dvp, dpn);
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return error;
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}
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@ -1376,7 +1427,7 @@ puffs_callremove(struct puffs_mount *pmp, void *dcookie, void *cookie,
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/*
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* XXX: can't use callremove now because can't catch setbacks with
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* it due to lack of a vnode argument.
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* it due to lack of a pnode argument.
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*/
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int
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puffs_remove(void *v)
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@ -1390,8 +1441,11 @@ puffs_remove(void *v)
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PUFFS_MSG_VARS(vn, remove);
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struct vnode *dvp = ap->a_dvp;
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struct vnode *vp = ap->a_vp;
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struct puffs_mount *pmp = MPTOPUFFSMP(dvp->v_mount);
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struct puffs_node *dpn = VPTOPP(dvp);
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struct puffs_node *pn = VPTOPP(vp);
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struct componentname *cnp = ap->a_cnp;
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struct mount *mp = dvp->v_mount;
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struct puffs_mount *pmp = MPTOPUFFSMP(mp);
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int error;
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PUFFS_MSG_ALLOC(vn, remove);
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@ -1401,17 +1455,20 @@ puffs_remove(void *v)
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puffs_msg_setinfo(park_remove, PUFFSOP_VN,
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PUFFS_VN_REMOVE, VPTOPNC(dvp));
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PUFFS_MSG_ENQUEUEWAIT2(pmp, park_remove,
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dvp->v_data, vp->v_data, error);
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puffs_msg_enqueue(pmp, park_remove);
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REFPN_AND_UNLOCKVP(dvp, dpn);
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if (dvp == vp)
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REFPN(pn);
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else
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REFPN_AND_UNLOCKVP(vp, pn);
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error = puffs_msg_wait2(pmp, park_remove, dpn, pn);
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PUFFS_MSG_RELEASE(remove);
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error = checkerr(pmp, error, __func__);
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vput(vp);
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if (dvp == vp)
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vrele(dvp);
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else
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vput(dvp);
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RELEPN_AND_VP(dvp, dpn);
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RELEPN_AND_VP(vp, pn);
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error = checkerr(pmp, error, __func__);
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return error;
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}
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@ -1427,8 +1484,10 @@ puffs_mkdir(void *v)
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} */ *ap = v;
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PUFFS_MSG_VARS(vn, mkdir);
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struct vnode *dvp = ap->a_dvp;
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struct puffs_mount *pmp = MPTOPUFFSMP(dvp->v_mount);
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struct puffs_node *dpn = VPTOPP(dvp);
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struct componentname *cnp = ap->a_cnp;
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struct mount *mp = dvp->v_mount;
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struct puffs_mount *pmp = MPTOPUFFSMP(mp);
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int error;
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PUFFS_MSG_ALLOC(vn, mkdir);
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@ -1438,22 +1497,25 @@ puffs_mkdir(void *v)
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puffs_msg_setinfo(park_mkdir, PUFFSOP_VN,
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PUFFS_VN_MKDIR, VPTOPNC(dvp));
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PUFFS_MSG_ENQUEUEWAIT2(pmp, park_mkdir, dvp->v_data, NULL, error);
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puffs_msg_enqueue(pmp, park_mkdir);
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REFPN_AND_UNLOCKVP(dvp, dpn);
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error = puffs_msg_wait2(pmp, park_mkdir, dpn, NULL);
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error = checkerr(pmp, error, __func__);
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if (error)
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goto out;
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error = puffs_newnode(dvp->v_mount, dvp, ap->a_vpp,
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error = puffs_newnode(mp, dvp, ap->a_vpp,
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mkdir_msg->pvnr_newnode, cnp, VDIR, 0);
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if (error)
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puffs_abortbutton(pmp, PUFFS_ABORT_MKDIR, VPTOPNC(ap->a_dvp),
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puffs_abortbutton(pmp, PUFFS_ABORT_MKDIR, dpn->pn_cookie,
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mkdir_msg->pvnr_newnode, cnp);
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out:
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PUFFS_MSG_RELEASE(mkdir);
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if (error || (cnp->cn_flags & SAVESTART) == 0)
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PNBUF_PUT(cnp->cn_pnbuf);
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vput(ap->a_dvp);
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RELEPN_AND_VP(dvp, dpn);
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return error;
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}
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@ -1488,6 +1550,8 @@ puffs_rmdir(void *v)
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PUFFS_MSG_VARS(vn, rmdir);
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struct vnode *dvp = ap->a_dvp;
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struct vnode *vp = ap->a_vp;
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struct puffs_node *dpn = VPTOPP(dvp);
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struct puffs_node *pn = VPTOPP(vp);
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struct puffs_mount *pmp = MPTOPUFFSMP(dvp->v_mount);
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struct componentname *cnp = ap->a_cnp;
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int error;
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@ -1499,12 +1563,16 @@ puffs_rmdir(void *v)
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puffs_msg_setinfo(park_rmdir, PUFFSOP_VN,
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PUFFS_VN_RMDIR, VPTOPNC(dvp));
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PUFFS_MSG_ENQUEUEWAIT2(pmp, park_rmdir, dvp->v_data, vp->v_data, error);
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puffs_msg_enqueue(pmp, park_rmdir);
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REFPN_AND_UNLOCKVP(dvp, dpn);
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REFPN_AND_UNLOCKVP(vp, pn);
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error = puffs_msg_wait2(pmp, park_rmdir, dpn, pn);
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PUFFS_MSG_RELEASE(rmdir);
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/* XXX: some call cache_purge() *for both vnodes* here, investigate */
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vput(dvp);
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vput(vp);
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RELEPN_AND_VP(dvp, dpn);
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RELEPN_AND_VP(vp, pn);
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return error;
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}
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@ -1521,6 +1589,8 @@ puffs_link(void *v)
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PUFFS_MSG_VARS(vn, link);
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struct vnode *dvp = ap->a_dvp;
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struct vnode *vp = ap->a_vp;
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struct puffs_node *dpn = VPTOPP(dvp);
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struct puffs_node *pn = VPTOPP(vp);
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struct puffs_mount *pmp = MPTOPUFFSMP(dvp->v_mount);
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struct componentname *cnp = ap->a_cnp;
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int error;
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@ -1532,7 +1602,11 @@ puffs_link(void *v)
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puffs_msg_setinfo(park_link, PUFFSOP_VN,
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PUFFS_VN_LINK, VPTOPNC(dvp));
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PUFFS_MSG_ENQUEUEWAIT2(pmp, park_link, dvp->v_data, NULL, error);
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puffs_msg_enqueue(pmp, park_link);
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REFPN_AND_UNLOCKVP(dvp, dpn);
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REFPN(pn);
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error = puffs_msg_wait2(pmp, park_link, dpn, pn);
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PUFFS_MSG_RELEASE(link);
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error = checkerr(pmp, error, __func__);
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@ -1540,12 +1614,15 @@ puffs_link(void *v)
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/*
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* XXX: stay in touch with the cache. I don't like this, but
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* don't have a better solution either. See also puffs_rename().
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*
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* XXX2: can't use vp safely here
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*/
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if (error == 0)
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puffs_updatenode(vp, PUFFS_UPDATECTIME);
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PNBUF_PUT(cnp->cn_pnbuf);
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vput(dvp);
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RELEPN_AND_VP(dvp, dpn);
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puffs_releasenode(pn);
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return error;
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}
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@ -1563,36 +1640,42 @@ puffs_symlink(void *v)
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} */ *ap = v;
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PUFFS_MSG_VARS(vn, symlink);
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struct vnode *dvp = ap->a_dvp;
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struct puffs_node *dpn = VPTOPP(dvp);
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struct mount *mp = dvp->v_mount;
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struct puffs_mount *pmp = MPTOPUFFSMP(dvp->v_mount);
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struct componentname *cnp = ap->a_cnp;
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int error;
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*ap->a_vpp = NULL;
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PUFFS_MSG_ALLOC(vn, symlink);
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puffs_makecn(&symlink_msg->pvnr_cn, &symlink_msg->pvnr_cn_cred,
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&symlink_msg->pvnr_cn_cid, ap->a_cnp, PUFFS_USE_FULLPNBUF(pmp));
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&symlink_msg->pvnr_cn_cid, cnp, PUFFS_USE_FULLPNBUF(pmp));
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symlink_msg->pvnr_va = *ap->a_vap;
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(void)strlcpy(symlink_msg->pvnr_link, ap->a_target,
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sizeof(symlink_msg->pvnr_link));
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puffs_msg_setinfo(park_symlink, PUFFSOP_VN,
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PUFFS_VN_SYMLINK, VPTOPNC(dvp));
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PUFFS_MSG_ENQUEUEWAIT2(pmp, park_symlink, dvp->v_data, NULL, error);
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puffs_msg_enqueue(pmp, park_symlink);
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REFPN_AND_UNLOCKVP(dvp, dpn);
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error = puffs_msg_wait2(pmp, park_symlink, dpn, NULL);
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error = checkerr(pmp, error, __func__);
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if (error)
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goto out;
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error = puffs_newnode(ap->a_dvp->v_mount, ap->a_dvp, ap->a_vpp,
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symlink_msg->pvnr_newnode, ap->a_cnp, VLNK, 0);
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error = puffs_newnode(mp, dvp, ap->a_vpp,
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symlink_msg->pvnr_newnode, cnp, VLNK, 0);
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if (error)
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puffs_abortbutton(pmp, PUFFS_ABORT_SYMLINK, VPTOPNC(ap->a_dvp),
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symlink_msg->pvnr_newnode, ap->a_cnp);
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puffs_abortbutton(pmp, PUFFS_ABORT_SYMLINK, dpn->pn_cookie,
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symlink_msg->pvnr_newnode, cnp);
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out:
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PUFFS_MSG_RELEASE(symlink);
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if (error || (ap->a_cnp->cn_flags & SAVESTART) == 0)
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PNBUF_PUT(ap->a_cnp->cn_pnbuf);
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vput(ap->a_dvp);
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if (error || (cnp->cn_flags & SAVESTART) == 0)
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PNBUF_PUT(cnp->cn_pnbuf);
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RELEPN_AND_VP(dvp, dpn);
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return error;
|
||||
}
|
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Reference in New Issue