NetBSD/sys/kern/vfs_vnops.c
elad b5d09ef065 okay, since there was no way to divide this to two commits, here it goes..
introduce fileassoc(9), a kernel interface for associating meta-data with
files using in-kernel memory. this is very similar to what we had in
veriexec till now, only abstracted so it can be used more easily by more
consumers.

this also prompted the redesign of the interface, making it work on vnodes
and mounts and not directly on devices and inodes. internally, we still
use file-id but that's gonna change soon... the interface will remain
consistent.

as a result, veriexec went under some heavy changes to conform to the new
interface. since we no longer use device numbers to identify file-systems,
the veriexec sysctl stuff changed too: kern.veriexec.count.dev_N is now
kern.veriexec.tableN.* where 'N' is NOT the device number but rather a
way to distinguish several mounts.

also worth noting is the plugging of unmount/delete operations
wrt/fileassoc and veriexec.

tons of input from yamt@, wrstuden@, martin@, and christos@.
2006-07-14 18:41:40 +00:00

1057 lines
25 KiB
C

/* $NetBSD: vfs_vnops.c,v 1.113 2006/07/14 18:41:40 elad Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)vfs_vnops.c 8.14 (Berkeley) 6/15/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: vfs_vnops.c,v 1.113 2006/07/14 18:41:40 elad Exp $");
#include "opt_verified_exec.h"
#include "fs_union.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/poll.h>
#include <sys/kauth.h>
#include <miscfs/specfs/specdev.h>
#include <uvm/uvm_extern.h>
#include <uvm/uvm_readahead.h>
#ifdef UNION
#include <fs/union/union.h>
#endif
#if defined(LKM) || defined(UNION)
int (*vn_union_readdir_hook) (struct vnode **, struct file *, struct lwp *);
#endif
#ifdef VERIFIED_EXEC
#include <sys/verified_exec.h>
#endif
static int vn_read(struct file *fp, off_t *offset, struct uio *uio,
kauth_cred_t cred, int flags);
static int vn_write(struct file *fp, off_t *offset, struct uio *uio,
kauth_cred_t cred, int flags);
static int vn_closefile(struct file *fp, struct lwp *l);
static int vn_poll(struct file *fp, int events, struct lwp *l);
static int vn_fcntl(struct file *fp, u_int com, void *data, struct lwp *l);
static int vn_statfile(struct file *fp, struct stat *sb, struct lwp *l);
static int vn_ioctl(struct file *fp, u_long com, void *data, struct lwp *l);
const struct fileops vnops = {
vn_read, vn_write, vn_ioctl, vn_fcntl, vn_poll,
vn_statfile, vn_closefile, vn_kqfilter
};
/*
* Common code for vnode open operations.
* Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
*/
int
vn_open(struct nameidata *ndp, int fmode, int cmode)
{
struct vnode *vp;
struct mount *mp = NULL; /* XXX: GCC */
struct lwp *l = ndp->ni_cnd.cn_lwp;
kauth_cred_t cred = l->l_proc->p_cred;
struct vattr va;
int error;
#ifdef VERIFIED_EXEC
struct veriexec_file_entry *vfe = NULL;
char pathbuf[MAXPATHLEN];
size_t pathlen;
int (*copyfun)(const void *, void *, size_t, size_t *) =
ndp->ni_segflg == UIO_SYSSPACE ? copystr : copyinstr;
#endif /* VERIFIED_EXEC */
#ifdef VERIFIED_EXEC
error = (*copyfun)(ndp->ni_dirp, pathbuf, sizeof(pathbuf), &pathlen);
if (error) {
if (veriexec_verbose >= 1)
printf("veriexec: Can't copy path. (error=%d)\n",
error);
return (error);
}
#endif /* VERIFIED_EXEC */
restart:
if (fmode & O_CREAT) {
ndp->ni_cnd.cn_nameiop = CREATE;
ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
if ((fmode & O_EXCL) == 0 &&
((fmode & O_NOFOLLOW) == 0))
ndp->ni_cnd.cn_flags |= FOLLOW;
if ((error = namei(ndp)) != 0)
return (error);
if (ndp->ni_vp == NULL) {
#ifdef VERIFIED_EXEC
/* Lockdown mode: Prevent creation of new files. */
if (veriexec_strict >= 3) {
VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
printf("Veriexec: vn_open: Preventing "
"new file creation in %s.\n",
pathbuf);
vp = ndp->ni_dvp;
error = EPERM;
goto bad;
}
#endif /* VERIFIED_EXEC */
VATTR_NULL(&va);
va.va_type = VREG;
va.va_mode = cmode;
if (fmode & O_EXCL)
va.va_vaflags |= VA_EXCLUSIVE;
if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
vput(ndp->ni_dvp);
if ((error = vn_start_write(NULL, &mp,
V_WAIT | V_SLEEPONLY | V_PCATCH)) != 0)
return (error);
goto restart;
}
VOP_LEASE(ndp->ni_dvp, l, cred, LEASE_WRITE);
error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
&ndp->ni_cnd, &va);
vn_finished_write(mp, 0);
if (error)
return (error);
fmode &= ~O_TRUNC;
vp = ndp->ni_vp;
} else {
VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
if (ndp->ni_dvp == ndp->ni_vp)
vrele(ndp->ni_dvp);
else
vput(ndp->ni_dvp);
ndp->ni_dvp = NULL;
vp = ndp->ni_vp;
if (fmode & O_EXCL) {
error = EEXIST;
goto bad;
}
fmode &= ~O_CREAT;
}
} else {
ndp->ni_cnd.cn_nameiop = LOOKUP;
ndp->ni_cnd.cn_flags = LOCKLEAF;
if ((fmode & O_NOFOLLOW) == 0)
ndp->ni_cnd.cn_flags |= FOLLOW;
if ((error = namei(ndp)) != 0)
return (error);
vp = ndp->ni_vp;
}
if (vp->v_type == VSOCK) {
error = EOPNOTSUPP;
goto bad;
}
if (ndp->ni_vp->v_type == VLNK) {
error = EFTYPE;
goto bad;
}
#ifdef VERIFIED_EXEC
if ((error = VOP_GETATTR(vp, &va, cred, l)) != 0)
goto bad;
#endif
if ((fmode & O_CREAT) == 0) {
#ifdef VERIFIED_EXEC
if ((error = veriexec_verify(l, vp, pathbuf,
VERIEXEC_FILE, &vfe)) != 0)
goto bad;
#endif
if (fmode & FREAD) {
if ((error = VOP_ACCESS(vp, VREAD, cred, l)) != 0)
goto bad;
}
if (fmode & (FWRITE | O_TRUNC)) {
if (vp->v_type == VDIR) {
error = EISDIR;
goto bad;
}
if ((error = vn_writechk(vp)) != 0 ||
(error = VOP_ACCESS(vp, VWRITE, cred, l)) != 0)
goto bad;
#ifdef VERIFIED_EXEC
if (vfe != NULL) {
veriexec_report("Write access request.",
pathbuf, &va, l,
REPORT_NOVERBOSE,
REPORT_ALARM,
REPORT_NOPANIC);
/* IPS mode: Deny writing to monitored files. */
if (veriexec_strict >= 2) {
error = EPERM;
goto bad;
} else {
vfe->status = FINGERPRINT_NOTEVAL;
}
}
#endif
}
}
if (fmode & O_TRUNC) {
VOP_UNLOCK(vp, 0); /* XXX */
if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0) {
vrele(vp);
return (error);
}
VOP_LEASE(vp, l, cred, LEASE_WRITE);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */
VATTR_NULL(&va);
va.va_size = 0;
error = VOP_SETATTR(vp, &va, cred, l);
vn_finished_write(mp, 0);
if (error != 0)
goto bad;
}
if ((error = VOP_OPEN(vp, fmode, cred, l)) != 0)
goto bad;
if (vp->v_type == VREG &&
uvn_attach(vp, fmode & FWRITE ? VM_PROT_WRITE : 0) == NULL) {
error = EIO;
goto bad;
}
if (fmode & FWRITE)
vp->v_writecount++;
return (0);
bad:
vput(vp);
return (error);
}
/*
* Check for write permissions on the specified vnode.
* Prototype text segments cannot be written.
*/
int
vn_writechk(struct vnode *vp)
{
/*
* If the vnode is in use as a process's text,
* we can't allow writing.
*/
if (vp->v_flag & VTEXT)
return (ETXTBSY);
return (0);
}
/*
* Mark a vnode as having executable mappings.
*/
void
vn_markexec(struct vnode *vp)
{
if ((vp->v_flag & VEXECMAP) == 0) {
uvmexp.filepages -= vp->v_uobj.uo_npages;
uvmexp.execpages += vp->v_uobj.uo_npages;
}
vp->v_flag |= VEXECMAP;
}
/*
* Mark a vnode as being the text of a process.
* Fail if the vnode is currently writable.
*/
int
vn_marktext(struct vnode *vp)
{
if (vp->v_writecount != 0) {
KASSERT((vp->v_flag & VTEXT) == 0);
return (ETXTBSY);
}
vp->v_flag |= VTEXT;
vn_markexec(vp);
return (0);
}
/*
* Vnode close call
*
* Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node.
*/
int
vn_close(struct vnode *vp, int flags, kauth_cred_t cred, struct lwp *l)
{
int error;
if (flags & FWRITE)
vp->v_writecount--;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_CLOSE(vp, flags, cred, l);
vput(vp);
return (error);
}
/*
* Package up an I/O request on a vnode into a uio and do it.
*/
int
vn_rdwr(enum uio_rw rw, struct vnode *vp, caddr_t base, int len, off_t offset,
enum uio_seg segflg, int ioflg, kauth_cred_t cred, size_t *aresid,
struct lwp *l)
{
struct uio auio;
struct iovec aiov;
struct mount *mp = NULL;
int error;
if ((ioflg & IO_NODELOCKED) == 0) {
if (rw == UIO_READ) {
vn_lock(vp, LK_SHARED | LK_RETRY);
} else /* UIO_WRITE */ {
if (vp->v_type != VCHR &&
(error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH))
!= 0)
return (error);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
}
}
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
aiov.iov_base = base;
aiov.iov_len = len;
auio.uio_resid = len;
auio.uio_offset = offset;
auio.uio_rw = rw;
if (segflg == UIO_SYSSPACE) {
UIO_SETUP_SYSSPACE(&auio);
} else {
auio.uio_vmspace = l->l_proc->p_vmspace;
}
if (rw == UIO_READ) {
error = VOP_READ(vp, &auio, ioflg, cred);
} else {
error = VOP_WRITE(vp, &auio, ioflg, cred);
}
if (aresid)
*aresid = auio.uio_resid;
else
if (auio.uio_resid && error == 0)
error = EIO;
if ((ioflg & IO_NODELOCKED) == 0) {
if (rw == UIO_WRITE)
vn_finished_write(mp, 0);
VOP_UNLOCK(vp, 0);
}
return (error);
}
int
vn_readdir(struct file *fp, char *bf, int segflg, u_int count, int *done,
struct lwp *l, off_t **cookies, int *ncookies)
{
struct vnode *vp = (struct vnode *)fp->f_data;
struct iovec aiov;
struct uio auio;
int error, eofflag;
/* Limit the size on any kernel buffers used by VOP_READDIR */
count = min(MAXBSIZE, count);
unionread:
if (vp->v_type != VDIR)
return (EINVAL);
aiov.iov_base = bf;
aiov.iov_len = count;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_rw = UIO_READ;
if (segflg == UIO_SYSSPACE) {
UIO_SETUP_SYSSPACE(&auio);
} else {
KASSERT(l == curlwp);
auio.uio_vmspace = l->l_proc->p_vmspace;
}
auio.uio_resid = count;
vn_lock(vp, LK_SHARED | LK_RETRY);
auio.uio_offset = fp->f_offset;
error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies,
ncookies);
fp->f_offset = auio.uio_offset;
VOP_UNLOCK(vp, 0);
if (error)
return (error);
#if defined(UNION) || defined(LKM)
if (count == auio.uio_resid && vn_union_readdir_hook) {
struct vnode *ovp = vp;
error = (*vn_union_readdir_hook)(&vp, fp, l);
if (error)
return (error);
if (vp != ovp)
goto unionread;
}
#endif /* UNION || LKM */
if (count == auio.uio_resid && (vp->v_flag & VROOT) &&
(vp->v_mount->mnt_flag & MNT_UNION)) {
struct vnode *tvp = vp;
vp = vp->v_mount->mnt_vnodecovered;
VREF(vp);
fp->f_data = vp;
fp->f_offset = 0;
vrele(tvp);
goto unionread;
}
*done = count - auio.uio_resid;
return error;
}
/*
* File table vnode read routine.
*/
static int
vn_read(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
int flags)
{
struct vnode *vp = (struct vnode *)fp->f_data;
int count, error, ioflag;
struct lwp *l = curlwp;
VOP_LEASE(vp, l, cred, LEASE_READ);
ioflag = IO_ADV_ENCODE(fp->f_advice);
if (fp->f_flag & FNONBLOCK)
ioflag |= IO_NDELAY;
if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC))
ioflag |= IO_SYNC;
if (fp->f_flag & FALTIO)
ioflag |= IO_ALTSEMANTICS;
vn_lock(vp, LK_SHARED | LK_RETRY);
uio->uio_offset = *offset;
count = uio->uio_resid;
error = VOP_READ(vp, uio, ioflag, cred);
if (flags & FOF_UPDATE_OFFSET)
*offset += count - uio->uio_resid;
VOP_UNLOCK(vp, 0);
return (error);
}
/*
* File table vnode write routine.
*/
static int
vn_write(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
int flags)
{
struct vnode *vp = (struct vnode *)fp->f_data;
struct mount *mp;
int count, error, ioflag = IO_UNIT;
struct lwp *l = curlwp;
if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
ioflag |= IO_APPEND;
if (fp->f_flag & FNONBLOCK)
ioflag |= IO_NDELAY;
if (fp->f_flag & FFSYNC ||
(vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
ioflag |= IO_SYNC;
else if (fp->f_flag & FDSYNC)
ioflag |= IO_DSYNC;
if (fp->f_flag & FALTIO)
ioflag |= IO_ALTSEMANTICS;
mp = NULL;
if (vp->v_type != VCHR &&
(error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
return (error);
VOP_LEASE(vp, l, cred, LEASE_WRITE);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
uio->uio_offset = *offset;
count = uio->uio_resid;
error = VOP_WRITE(vp, uio, ioflag, cred);
if (flags & FOF_UPDATE_OFFSET) {
if (ioflag & IO_APPEND)
*offset = uio->uio_offset;
else
*offset += count - uio->uio_resid;
}
VOP_UNLOCK(vp, 0);
vn_finished_write(mp, 0);
return (error);
}
/*
* File table vnode stat routine.
*/
static int
vn_statfile(struct file *fp, struct stat *sb, struct lwp *l)
{
struct vnode *vp = (struct vnode *)fp->f_data;
return vn_stat(vp, sb, l);
}
int
vn_stat(struct vnode *vp, struct stat *sb, struct lwp *l)
{
struct vattr va;
int error;
mode_t mode;
error = VOP_GETATTR(vp, &va, l->l_proc->p_cred, l);
if (error)
return (error);
/*
* Copy from vattr table
*/
sb->st_dev = va.va_fsid;
sb->st_ino = va.va_fileid;
mode = va.va_mode;
switch (vp->v_type) {
case VREG:
mode |= S_IFREG;
break;
case VDIR:
mode |= S_IFDIR;
break;
case VBLK:
mode |= S_IFBLK;
break;
case VCHR:
mode |= S_IFCHR;
break;
case VLNK:
mode |= S_IFLNK;
break;
case VSOCK:
mode |= S_IFSOCK;
break;
case VFIFO:
mode |= S_IFIFO;
break;
default:
return (EBADF);
};
sb->st_mode = mode;
sb->st_nlink = va.va_nlink;
sb->st_uid = va.va_uid;
sb->st_gid = va.va_gid;
sb->st_rdev = va.va_rdev;
sb->st_size = va.va_size;
sb->st_atimespec = va.va_atime;
sb->st_mtimespec = va.va_mtime;
sb->st_ctimespec = va.va_ctime;
sb->st_birthtimespec = va.va_birthtime;
sb->st_blksize = va.va_blocksize;
sb->st_flags = va.va_flags;
sb->st_gen = 0;
sb->st_blocks = va.va_bytes / S_BLKSIZE;
return (0);
}
/*
* File table vnode fcntl routine.
*/
static int
vn_fcntl(struct file *fp, u_int com, void *data, struct lwp *l)
{
struct vnode *vp = ((struct vnode *)fp->f_data);
int error;
error = VOP_FCNTL(vp, com, data, fp->f_flag, l->l_proc->p_cred, l);
return (error);
}
/*
* File table vnode ioctl routine.
*/
static int
vn_ioctl(struct file *fp, u_long com, void *data, struct lwp *l)
{
struct vnode *vp = ((struct vnode *)fp->f_data);
struct proc *p = l->l_proc;
struct vattr vattr;
int error;
switch (vp->v_type) {
case VREG:
case VDIR:
if (com == FIONREAD) {
error = VOP_GETATTR(vp, &vattr, l->l_proc->p_cred, l);
if (error)
return (error);
*(int *)data = vattr.va_size - fp->f_offset;
return (0);
}
if ((com == FIONWRITE) || (com == FIONSPACE)) {
/*
* Files don't have send queues, so there never
* are any bytes in them, nor is there any
* open space in them.
*/
*(int *)data = 0;
return (0);
}
if (com == FIOGETBMAP) {
daddr_t *block;
if (*(daddr_t *)data < 0)
return (EINVAL);
block = (daddr_t *)data;
return (VOP_BMAP(vp, *block, NULL, block, NULL));
}
if (com == OFIOGETBMAP) {
daddr_t ibn, obn;
if (*(int32_t *)data < 0)
return (EINVAL);
ibn = (daddr_t)*(int32_t *)data;
error = VOP_BMAP(vp, ibn, NULL, &obn, NULL);
*(int32_t *)data = (int32_t)obn;
return error;
}
if (com == FIONBIO || com == FIOASYNC) /* XXX */
return (0); /* XXX */
/* fall into ... */
case VFIFO:
case VCHR:
case VBLK:
error = VOP_IOCTL(vp, com, data, fp->f_flag,
l->l_proc->p_cred, l);
if (error == 0 && com == TIOCSCTTY) {
if (p->p_session->s_ttyvp)
vrele(p->p_session->s_ttyvp);
p->p_session->s_ttyvp = vp;
VREF(vp);
}
return (error);
default:
return (EPASSTHROUGH);
}
}
/*
* File table vnode poll routine.
*/
static int
vn_poll(struct file *fp, int events, struct lwp *l)
{
return (VOP_POLL(((struct vnode *)fp->f_data), events, l));
}
/*
* File table vnode kqfilter routine.
*/
int
vn_kqfilter(struct file *fp, struct knote *kn)
{
return (VOP_KQFILTER((struct vnode *)fp->f_data, kn));
}
/*
* Check that the vnode is still valid, and if so
* acquire requested lock.
*/
int
vn_lock(struct vnode *vp, int flags)
{
int error;
#if 0
KASSERT(vp->v_usecount > 0 || (flags & LK_INTERLOCK) != 0
|| (vp->v_flag & VONWORKLST) != 0);
#endif
KASSERT((flags &
~(LK_INTERLOCK|LK_SHARED|LK_EXCLUSIVE|LK_DRAIN|LK_NOWAIT|LK_RETRY|
LK_SETRECURSE|LK_CANRECURSE))
== 0);
do {
if ((flags & LK_INTERLOCK) == 0)
simple_lock(&vp->v_interlock);
if (vp->v_flag & VXLOCK) {
if (flags & LK_NOWAIT) {
simple_unlock(&vp->v_interlock);
return EBUSY;
}
vp->v_flag |= VXWANT;
ltsleep(vp, PINOD | PNORELOCK,
"vn_lock", 0, &vp->v_interlock);
error = ENOENT;
} else {
error = VOP_LOCK(vp,
(flags & ~LK_RETRY) | LK_INTERLOCK);
if (error == 0 || error == EDEADLK || error == EBUSY)
return (error);
}
flags &= ~LK_INTERLOCK;
} while (flags & LK_RETRY);
return (error);
}
/*
* File table vnode close routine.
*/
static int
vn_closefile(struct file *fp, struct lwp *l)
{
return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
fp->f_cred, l));
}
/*
* Enable LK_CANRECURSE on lock. Return prior status.
*/
u_int
vn_setrecurse(struct vnode *vp)
{
struct lock *lkp = &vp->v_lock;
u_int retval = lkp->lk_flags & LK_CANRECURSE;
lkp->lk_flags |= LK_CANRECURSE;
return retval;
}
/*
* Called when done with locksetrecurse.
*/
void
vn_restorerecurse(struct vnode *vp, u_int flags)
{
struct lock *lkp = &vp->v_lock;
lkp->lk_flags &= ~LK_CANRECURSE;
lkp->lk_flags |= flags;
}
int
vn_cow_establish(struct vnode *vp,
int (*func)(void *, struct buf *), void *cookie)
{
int s;
struct spec_cow_entry *e;
MALLOC(e, struct spec_cow_entry *, sizeof(struct spec_cow_entry),
M_DEVBUF, M_WAITOK);
e->ce_func = func;
e->ce_cookie = cookie;
SPEC_COW_LOCK(vp->v_specinfo, s);
vp->v_spec_cow_req++;
while (vp->v_spec_cow_count > 0)
ltsleep(&vp->v_spec_cow_req, PRIBIO, "cowlist", 0,
&vp->v_spec_cow_slock);
SLIST_INSERT_HEAD(&vp->v_spec_cow_head, e, ce_list);
vp->v_spec_cow_req--;
if (vp->v_spec_cow_req == 0)
wakeup(&vp->v_spec_cow_req);
SPEC_COW_UNLOCK(vp->v_specinfo, s);
return 0;
}
int
vn_cow_disestablish(struct vnode *vp,
int (*func)(void *, struct buf *), void *cookie)
{
int s;
struct spec_cow_entry *e;
SPEC_COW_LOCK(vp->v_specinfo, s);
vp->v_spec_cow_req++;
while (vp->v_spec_cow_count > 0)
ltsleep(&vp->v_spec_cow_req, PRIBIO, "cowlist", 0,
&vp->v_spec_cow_slock);
SLIST_FOREACH(e, &vp->v_spec_cow_head, ce_list)
if (e->ce_func == func && e->ce_cookie == cookie) {
SLIST_REMOVE(&vp->v_spec_cow_head, e,
spec_cow_entry, ce_list);
FREE(e, M_DEVBUF);
break;
}
vp->v_spec_cow_req--;
if (vp->v_spec_cow_req == 0)
wakeup(&vp->v_spec_cow_req);
SPEC_COW_UNLOCK(vp->v_specinfo, s);
return e ? 0 : EINVAL;
}
/*
* Simplified in-kernel wrapper calls for extended attribute access.
* Both calls pass in a NULL credential, authorizing a "kernel" access.
* Set IO_NODELOCKED in ioflg if the vnode is already locked.
*/
int
vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
const char *attrname, size_t *buflen, void *bf, struct lwp *l)
{
struct uio auio;
struct iovec aiov;
int error;
aiov.iov_len = *buflen;
aiov.iov_base = bf;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_rw = UIO_READ;
auio.uio_offset = 0;
auio.uio_resid = *buflen;
UIO_SETUP_SYSSPACE(&auio);
if ((ioflg & IO_NODELOCKED) == 0)
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
l);
if ((ioflg & IO_NODELOCKED) == 0)
VOP_UNLOCK(vp, 0);
if (error == 0)
*buflen = *buflen - auio.uio_resid;
return (error);
}
/*
* XXX Failure mode if partially written?
*/
int
vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
const char *attrname, size_t buflen, const void *bf, struct lwp *l)
{
struct uio auio;
struct iovec aiov;
struct mount *mp = NULL; /* XXX: GCC */
int error;
aiov.iov_len = buflen;
aiov.iov_base = __UNCONST(bf); /* XXXUNCONST kills const */
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_rw = UIO_WRITE;
auio.uio_offset = 0;
auio.uio_resid = buflen;
UIO_SETUP_SYSSPACE(&auio);
if ((ioflg & IO_NODELOCKED) == 0) {
if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
return (error);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
}
error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, l);
if ((ioflg & IO_NODELOCKED) == 0) {
vn_finished_write(mp, 0);
VOP_UNLOCK(vp, 0);
}
return (error);
}
int
vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
const char *attrname, struct lwp *l)
{
struct mount *mp = NULL; /* XXX: GCC */
int error;
if ((ioflg & IO_NODELOCKED) == 0) {
if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
return (error);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
}
error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, l);
if (error == EOPNOTSUPP)
error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
NULL, l);
if ((ioflg & IO_NODELOCKED) == 0) {
vn_finished_write(mp, 0);
VOP_UNLOCK(vp, 0);
}
return (error);
}
/*
* Preparing to start a filesystem write operation. If the operation is
* permitted, then we bump the count of operations in progress and
* proceed. If a suspend request is in progress, we wait until the
* suspension is over, and then proceed.
* V_PCATCH adds PCATCH to the tsleep flags.
* V_WAIT waits until suspension is over. Otherwise returns EWOULDBLOCK.
* V_SLEEPONLY wait, but do not bump the operations count.
* V_LOWER this is a lower level operation. No further vnodes should be
* locked. Otherwise it is a upper level operation. No vnodes
* should be locked.
*/
int
vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
{
struct mount *mp;
int error, mask, prio;
/*
* If a vnode is provided, get and return the mount point that
* to which it will write.
*/
if (vp != NULL) {
*mpp = vp->v_mount;
}
if ((mp = *mpp) == NULL)
return (0);
mp = mp->mnt_leaf;
/*
* Check on status of suspension.
*/
prio = PUSER - 1;
if (flags & V_PCATCH)
prio |= PCATCH;
if ((flags & V_LOWER) == 0)
mask = IMNT_SUSPEND;
else
mask = IMNT_SUSPENDLOW;
while ((mp->mnt_iflag & mask) != 0) {
if ((flags & V_WAIT) == 0)
return (EWOULDBLOCK);
error = tsleep(&mp->mnt_flag, prio, "suspfs", 0);
if (error)
return (error);
}
if (flags & V_SLEEPONLY)
return (0);
simple_lock(&mp->mnt_slock);
if ((flags & V_LOWER) == 0)
mp->mnt_writeopcountupper++;
else
mp->mnt_writeopcountlower++;
simple_unlock(&mp->mnt_slock);
return (0);
}
/*
* Filesystem write operation has completed. If we are suspending and this
* operation is the last one, notify the suspender that the suspension is
* now in effect.
*/
void
vn_finished_write(struct mount *mp, int flags)
{
if (mp == NULL)
return;
mp = mp->mnt_leaf;
simple_lock(&mp->mnt_slock);
if ((flags & V_LOWER) == 0) {
mp->mnt_writeopcountupper--;
if (mp->mnt_writeopcountupper < 0)
printf("vn_finished_write: neg cnt upper=%d\n",
mp->mnt_writeopcountupper);
if ((mp->mnt_iflag & IMNT_SUSPEND) != 0 &&
mp->mnt_writeopcountupper <= 0)
wakeup(&mp->mnt_writeopcountupper);
} else {
mp->mnt_writeopcountlower--;
if (mp->mnt_writeopcountlower < 0)
printf("vn_finished_write: neg cnt lower=%d\n",
mp->mnt_writeopcountlower);
if ((mp->mnt_iflag & IMNT_SUSPENDLOW) != 0 &&
mp->mnt_writeopcountupper <= 0)
wakeup(&mp->mnt_writeopcountlower);
}
simple_unlock(&mp->mnt_slock);
}
void
vn_ra_allocctx(struct vnode *vp)
{
struct uvm_ractx *ra = NULL;
if (vp->v_type != VREG) {
return;
}
if (vp->v_ractx != NULL) {
return;
}
simple_lock(&vp->v_interlock);
if (vp->v_ractx == NULL) {
simple_unlock(&vp->v_interlock);
ra = uvm_ra_allocctx();
simple_lock(&vp->v_interlock);
if (ra != NULL && vp->v_ractx == NULL) {
vp->v_ractx = ra;
ra = NULL;
}
}
simple_unlock(&vp->v_interlock);
if (ra != NULL) {
uvm_ra_freectx(ra);
}
}