freebsd-skq/sys/fs/smbfs/smbfs_node.c
Konstantin Belousov 6470c8d3db Rework v_object lifecycle for vnodes.
Current implementation of vnode_create_vobject() and
vnode_destroy_vobject() is written so that it prepared to handle the
vm object destruction for live vnode.  Practically, no filesystems use
this, except for some remnants that were present in UFS till today.
One of the consequences of that model is that each filesystem must
call vnode_destroy_vobject() in VOP_RECLAIM() or earlier, as result
all of them get rid of the v_object in reclaim.

Move the call to vnode_destroy_vobject() to vgonel() before
VOP_RECLAIM().  This makes v_object stable: either the object is NULL,
or it is valid vm object till the vnode reclamation.  Remove code from
vnode_create_vobject() to handle races with the parallel destruction.

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D21412
2019-08-29 07:50:25 +00:00

409 lines
11 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2000-2001 Boris Popov
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fnv_hash.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <netsmb/smb.h>
#include <netsmb/smb_conn.h>
#include <netsmb/smb_subr.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
/*#include <vm/vm_page.h>
#include <vm/vm_object.h>*/
#include <fs/smbfs/smbfs.h>
#include <fs/smbfs/smbfs_node.h>
#include <fs/smbfs/smbfs_subr.h>
extern struct vop_vector smbfs_vnodeops; /* XXX -> .h file */
static MALLOC_DEFINE(M_SMBNODE, "smbufs_node", "SMBFS vnode private part");
static MALLOC_DEFINE(M_SMBNODENAME, "smbufs_nname", "SMBFS node name");
u_int32_t __inline
smbfs_hash(const u_char *name, int nmlen)
{
return (fnv_32_buf(name, nmlen, FNV1_32_INIT));
}
static char *
smbfs_name_alloc(const u_char *name, int nmlen)
{
u_char *cp;
nmlen++;
cp = malloc(nmlen, M_SMBNODENAME, M_WAITOK);
bcopy(name, cp, nmlen - 1);
cp[nmlen - 1] = 0;
return cp;
}
static void
smbfs_name_free(u_char *name)
{
free(name, M_SMBNODENAME);
}
static int __inline
smbfs_vnode_cmp(struct vnode *vp, void *_sc)
{
struct smbnode *np;
struct smbcmp *sc;
np = (struct smbnode *) vp->v_data;
sc = (struct smbcmp *) _sc;
if (np->n_parent != sc->n_parent || np->n_nmlen != sc->n_nmlen ||
bcmp(sc->n_name, np->n_name, sc->n_nmlen) != 0)
return 1;
return 0;
}
static int
smbfs_node_alloc(struct mount *mp, struct vnode *dvp, const char *dirnm,
int dirlen, const char *name, int nmlen, char sep,
struct smbfattr *fap, struct vnode **vpp)
{
struct vattr vattr;
struct thread *td = curthread; /* XXX */
struct smbmount *smp = VFSTOSMBFS(mp);
struct smbnode *np, *dnp;
struct vnode *vp, *vp2;
struct smbcmp sc;
char *p, *rpath;
int error, rplen;
sc.n_parent = dvp;
sc.n_nmlen = nmlen;
sc.n_name = name;
if (smp->sm_root != NULL && dvp == NULL) {
SMBERROR("do not allocate root vnode twice!\n");
return EINVAL;
}
if (nmlen == 2 && bcmp(name, "..", 2) == 0) {
if (dvp == NULL)
return EINVAL;
vp = VTOSMB(VTOSMB(dvp)->n_parent)->n_vnode;
error = vget(vp, LK_EXCLUSIVE, td);
if (error == 0)
*vpp = vp;
return error;
} else if (nmlen == 1 && name[0] == '.') {
SMBERROR("do not call me with dot!\n");
return EINVAL;
}
dnp = dvp ? VTOSMB(dvp) : NULL;
if (dnp == NULL && dvp != NULL) {
vn_printf(dvp, "smbfs_node_alloc: dead parent vnode ");
return EINVAL;
}
error = vfs_hash_get(mp, smbfs_hash(name, nmlen), LK_EXCLUSIVE, td,
vpp, smbfs_vnode_cmp, &sc);
if (error)
return (error);
if (*vpp) {
np = VTOSMB(*vpp);
/* Force cached attributes to be refreshed if stale. */
(void)VOP_GETATTR(*vpp, &vattr, td->td_ucred);
/*
* If the file type on the server is inconsistent with
* what it was when we created the vnode, kill the
* bogus vnode now and fall through to the code below
* to create a new one with the right type.
*/
if (((*vpp)->v_type == VDIR &&
(np->n_dosattr & SMB_FA_DIR) == 0) ||
((*vpp)->v_type == VREG &&
(np->n_dosattr & SMB_FA_DIR) != 0)) {
vgone(*vpp);
vput(*vpp);
}
else {
SMBVDEBUG("vnode taken from the hashtable\n");
return (0);
}
}
/*
* If we don't have node attributes, then it is an explicit lookup
* for an existing vnode.
*/
if (fap == NULL)
return ENOENT;
error = getnewvnode("smbfs", mp, &smbfs_vnodeops, vpp);
if (error)
return (error);
vp = *vpp;
np = malloc(sizeof *np, M_SMBNODE, M_WAITOK | M_ZERO);
rplen = dirlen;
if (sep != '\0')
rplen++;
rplen += nmlen;
rpath = malloc(rplen + 1, M_SMBNODENAME, M_WAITOK);
p = rpath;
bcopy(dirnm, p, dirlen);
p += dirlen;
if (sep != '\0')
*p++ = sep;
if (name != NULL) {
bcopy(name, p, nmlen);
p += nmlen;
}
*p = '\0';
MPASS(p == rpath + rplen);
lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
/* Vnode initialization */
vp->v_type = fap->fa_attr & SMB_FA_DIR ? VDIR : VREG;
vp->v_data = np;
np->n_vnode = vp;
np->n_mount = VFSTOSMBFS(mp);
np->n_rpath = rpath;
np->n_rplen = rplen;
np->n_nmlen = nmlen;
np->n_name = smbfs_name_alloc(name, nmlen);
np->n_ino = fap->fa_ino;
if (dvp) {
ASSERT_VOP_LOCKED(dvp, "smbfs_node_alloc");
np->n_parent = dvp;
np->n_parentino = VTOSMB(dvp)->n_ino;
if (/*vp->v_type == VDIR &&*/ (dvp->v_vflag & VV_ROOT) == 0) {
vref(dvp);
np->n_flag |= NREFPARENT;
}
} else if (vp->v_type == VREG)
SMBERROR("new vnode '%s' born without parent ?\n", np->n_name);
error = insmntque(vp, mp);
if (error) {
free(np, M_SMBNODE);
return (error);
}
error = vfs_hash_insert(vp, smbfs_hash(name, nmlen), LK_EXCLUSIVE,
td, &vp2, smbfs_vnode_cmp, &sc);
if (error)
return (error);
if (vp2 != NULL)
*vpp = vp2;
return (0);
}
int
smbfs_nget(struct mount *mp, struct vnode *dvp, const char *name, int nmlen,
struct smbfattr *fap, struct vnode **vpp)
{
struct smbnode *dnp, *np;
struct vnode *vp;
int error, sep;
dnp = (dvp) ? VTOSMB(dvp) : NULL;
sep = 0;
if (dnp != NULL) {
sep = SMBFS_DNP_SEP(dnp);
error = smbfs_node_alloc(mp, dvp, dnp->n_rpath, dnp->n_rplen,
name, nmlen, sep, fap, &vp);
} else
error = smbfs_node_alloc(mp, NULL, "\\", 1, name, nmlen,
sep, fap, &vp);
if (error)
return error;
MPASS(vp != NULL);
np = VTOSMB(vp);
if (fap)
smbfs_attr_cacheenter(vp, fap);
*vpp = vp;
return 0;
}
/*
* Free smbnode, and give vnode back to system
*/
int
smbfs_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
struct thread *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct vnode *dvp;
struct smbnode *np = VTOSMB(vp);
struct smbmount *smp = VTOSMBFS(vp);
SMBVDEBUG("%s,%d\n", np->n_name, vrefcnt(vp));
KASSERT((np->n_flag & NOPEN) == 0, ("file not closed before reclaim"));
dvp = (np->n_parent && (np->n_flag & NREFPARENT)) ?
np->n_parent : NULL;
/*
* Remove the vnode from its hash chain.
*/
vfs_hash_remove(vp);
if (np->n_name)
smbfs_name_free(np->n_name);
if (np->n_rpath)
free(np->n_rpath, M_SMBNODENAME);
free(np, M_SMBNODE);
vp->v_data = NULL;
if (dvp != NULL) {
vrele(dvp);
/*
* Indicate that we released something; see comment
* in smbfs_unmount().
*/
smp->sm_didrele = 1;
}
return 0;
}
int
smbfs_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
struct thread *td = ap->a_td;
struct ucred *cred = td->td_ucred;
struct vnode *vp = ap->a_vp;
struct smbnode *np = VTOSMB(vp);
struct smb_cred *scred;
struct vattr va;
SMBVDEBUG("%s: %d\n", VTOSMB(vp)->n_name, vrefcnt(vp));
if ((np->n_flag & NOPEN) != 0) {
scred = smbfs_malloc_scred();
smb_makescred(scred, td, cred);
smbfs_vinvalbuf(vp, td);
if (vp->v_type == VREG) {
VOP_GETATTR(vp, &va, cred);
smbfs_smb_close(np->n_mount->sm_share, np->n_fid,
&np->n_mtime, scred);
} else if (vp->v_type == VDIR) {
if (np->n_dirseq != NULL) {
smbfs_findclose(np->n_dirseq, scred);
np->n_dirseq = NULL;
}
}
np->n_flag &= ~NOPEN;
smbfs_attr_cacheremove(vp);
smbfs_free_scred(scred);
}
if (np->n_flag & NGONE)
vrecycle(vp);
return (0);
}
/*
* routines to maintain vnode attributes cache
* smbfs_attr_cacheenter: unpack np.i to vattr structure
*/
void
smbfs_attr_cacheenter(struct vnode *vp, struct smbfattr *fap)
{
struct smbnode *np = VTOSMB(vp);
if (vp->v_type == VREG) {
if (np->n_size != fap->fa_size) {
np->n_size = fap->fa_size;
vnode_pager_setsize(vp, np->n_size);
}
} else if (vp->v_type == VDIR) {
np->n_size = 16384; /* should be a better way ... */
} else
return;
np->n_mtime = fap->fa_mtime;
np->n_dosattr = fap->fa_attr;
np->n_attrage = time_second;
return;
}
int
smbfs_attr_cachelookup(struct vnode *vp, struct vattr *va)
{
struct smbnode *np = VTOSMB(vp);
struct smbmount *smp = VTOSMBFS(vp);
int diff;
diff = time_second - np->n_attrage;
if (diff > 2) /* XXX should be configurable */
return ENOENT;
va->va_type = vp->v_type; /* vnode type (for create) */
va->va_flags = 0; /* flags defined for file */
if (vp->v_type == VREG) {
va->va_mode = smp->sm_file_mode; /* files access mode and type */
if (np->n_dosattr & SMB_FA_RDONLY) {
va->va_mode &= ~(S_IWUSR|S_IWGRP|S_IWOTH);
va->va_flags |= UF_READONLY;
}
} else if (vp->v_type == VDIR) {
va->va_mode = smp->sm_dir_mode; /* files access mode and type */
} else
return EINVAL;
va->va_size = np->n_size;
va->va_nlink = 1; /* number of references to file */
va->va_uid = smp->sm_uid; /* owner user id */
va->va_gid = smp->sm_gid; /* owner group id */
va->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
va->va_fileid = np->n_ino; /* file id */
if (va->va_fileid == 0)
va->va_fileid = 2;
va->va_blocksize = SSTOVC(smp->sm_share)->vc_txmax;
va->va_mtime = np->n_mtime;
va->va_atime = va->va_ctime = va->va_mtime; /* time file changed */
va->va_gen = VNOVAL; /* generation number of file */
if (np->n_dosattr & SMB_FA_HIDDEN)
va->va_flags |= UF_HIDDEN;
if (np->n_dosattr & SMB_FA_SYSTEM)
va->va_flags |= UF_SYSTEM;
/*
* We don't set the archive bit for directories.
*/
if ((vp->v_type != VDIR) && (np->n_dosattr & SMB_FA_ARCHIVE))
va->va_flags |= UF_ARCHIVE;
va->va_rdev = NODEV; /* device the special file represents */
va->va_bytes = va->va_size; /* bytes of disk space held by file */
va->va_filerev = 0; /* file modification number */
va->va_vaflags = 0; /* operations flags */
return 0;
}