FreeBSD-5.3/sys/kern/vfs_vnops.c
/*
* 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.
* 4. 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 8.2 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/kern/vfs_vnops.c,v 1.207 2004/08/15 06:24:41 jmg Exp $");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/kdb.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mac.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/filio.h>
#include <sys/sx.h>
#include <sys/ttycom.h>
#include <sys/conf.h>
#include <sys/syslog.h>
#include <sys/unistd.h>
static fo_rdwr_t vn_read;
static fo_rdwr_t vn_write;
static fo_ioctl_t vn_ioctl;
static fo_poll_t vn_poll;
static fo_kqfilter_t vn_kqfilter;
static fo_stat_t vn_statfile;
static fo_close_t vn_closefile;
struct fileops vnops = {
.fo_read = vn_read,
.fo_write = vn_write,
.fo_ioctl = vn_ioctl,
.fo_poll = vn_poll,
.fo_kqfilter = vn_kqfilter,
.fo_stat = vn_statfile,
.fo_close = vn_closefile,
.fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
};
int
vn_open(ndp, flagp, cmode, fdidx)
struct nameidata *ndp;
int *flagp, cmode, fdidx;
{
struct thread *td = ndp->ni_cnd.cn_thread;
return (vn_open_cred(ndp, flagp, cmode, td->td_ucred, fdidx));
}
/*
* Common code for vnode open operations.
* Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
*
* Note that this does NOT free nameidata for the successful case,
* due to the NDINIT being done elsewhere.
*/
int
vn_open_cred(ndp, flagp, cmode, cred, fdidx)
struct nameidata *ndp;
int *flagp, cmode;
struct ucred *cred;
int fdidx;
{
struct vnode *vp;
struct mount *mp;
struct thread *td = ndp->ni_cnd.cn_thread;
struct vattr vat;
struct vattr *vap = &vat;
int mode, fmode, error;
#ifdef LOOKUP_SHARED
int exclusive; /* The current intended lock state */
exclusive = 0;
#endif
GIANT_REQUIRED;
restart:
fmode = *flagp;
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;
bwillwrite();
if ((error = namei(ndp)) != 0)
return (error);
if (ndp->ni_vp == NULL) {
VATTR_NULL(vap);
vap->va_type = VREG;
vap->va_mode = cmode;
if (fmode & O_EXCL)
vap->va_vaflags |= VA_EXCLUSIVE;
if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
NDFREE(ndp, NDF_ONLY_PNBUF);
vput(ndp->ni_dvp);
if ((error = vn_start_write(NULL, &mp,
V_XSLEEP | PCATCH)) != 0)
return (error);
goto restart;
}
#ifdef MAC
error = mac_check_vnode_create(cred, ndp->ni_dvp,
&ndp->ni_cnd, vap);
if (error == 0) {
#endif
VOP_LEASE(ndp->ni_dvp, td, cred, LEASE_WRITE);
error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
&ndp->ni_cnd, vap);
#ifdef MAC
}
#endif
vput(ndp->ni_dvp);
vn_finished_write(mp);
if (error) {
NDFREE(ndp, NDF_ONLY_PNBUF);
return (error);
}
ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create");
ASSERT_VOP_LOCKED(ndp->ni_vp, "create");
fmode &= ~O_TRUNC;
vp = ndp->ni_vp;
#ifdef LOOKUP_SHARED
exclusive = 1;
#endif
} else {
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;
#ifdef LOOKUP_SHARED
ndp->ni_cnd.cn_flags =
((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) |
LOCKSHARED | LOCKLEAF;
#else
ndp->ni_cnd.cn_flags =
((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
#endif
if ((error = namei(ndp)) != 0)
return (error);
vp = ndp->ni_vp;
}
if (vp->v_type == VLNK) {
error = EMLINK;
goto bad;
}
if (vp->v_type == VSOCK) {
error = EOPNOTSUPP;
goto bad;
}
mode = 0;
if (fmode & (FWRITE | O_TRUNC)) {
if (vp->v_type == VDIR) {
error = EISDIR;
goto bad;
}
mode |= VWRITE;
}
if (fmode & FREAD)
mode |= VREAD;
if (fmode & O_APPEND)
mode |= VAPPEND;
#ifdef MAC
error = mac_check_vnode_open(cred, vp, mode);
if (error)
goto bad;
#endif
if ((fmode & O_CREAT) == 0) {
if (mode & VWRITE) {
error = vn_writechk(vp);
if (error)
goto bad;
}
if (mode) {
error = VOP_ACCESS(vp, mode, cred, td);
if (error)
goto bad;
}
}
if ((error = VOP_GETATTR(vp, vap, cred, td)) == 0) {
vp->v_cachedfs = vap->va_fsid;
vp->v_cachedid = vap->va_fileid;
}
if ((error = VOP_OPEN(vp, fmode, cred, td, fdidx)) != 0)
goto bad;
/*
* Make sure that a VM object is created for VMIO support.
*/
if (vn_canvmio(vp) == TRUE) {
#ifdef LOOKUP_SHARED
int flock;
if (!exclusive && VOP_GETVOBJECT(vp, NULL) != 0)
VOP_LOCK(vp, LK_UPGRADE, td);
/*
* In cases where the object is marked as dead object_create
* will unlock and relock exclusive. It is safe to call in
* here with a shared lock because we only examine fields that
* the shared lock guarantees will be stable. In the UPGRADE
* case it is not likely that anyone has used this vnode yet
* so there will be no contention. The logic after this call
* restores the requested locking state.
*/
#endif
if ((error = vfs_object_create(vp, td, cred)) != 0) {
VOP_UNLOCK(vp, 0, td);
VOP_CLOSE(vp, fmode, cred, td);
NDFREE(ndp, NDF_ONLY_PNBUF);
vrele(vp);
*flagp = fmode;
return (error);
}
#ifdef LOOKUP_SHARED
flock = VOP_ISLOCKED(vp, td);
if (!exclusive && flock == LK_EXCLUSIVE)
VOP_LOCK(vp, LK_DOWNGRADE, td);
#endif
}
if (fmode & FWRITE)
vp->v_writecount++;
*flagp = fmode;
ASSERT_VOP_LOCKED(vp, "vn_open_cred");
return (0);
bad:
NDFREE(ndp, NDF_ONLY_PNBUF);
vput(vp);
*flagp = fmode;
ndp->ni_vp = NULL;
return (error);
}
/*
* Check for write permissions on the specified vnode.
* Prototype text segments cannot be written.
*/
int
vn_writechk(vp)
register struct vnode *vp;
{
ASSERT_VOP_LOCKED(vp, "vn_writechk");
/*
* If there's shared text associated with
* the vnode, try to free it up once. If
* we fail, we can't allow writing.
*/
if (vp->v_vflag & VV_TEXT)
return (ETXTBSY);
return (0);
}
/*
* Vnode close call
*/
int
vn_close(vp, flags, file_cred, td)
register struct vnode *vp;
int flags;
struct ucred *file_cred;
struct thread *td;
{
int error;
GIANT_REQUIRED;
if (flags & FWRITE)
vp->v_writecount--;
error = VOP_CLOSE(vp, flags, file_cred, td);
/*
* XXX - In certain instances VOP_CLOSE has to do the vrele
* itself. If the vrele has been done, it will return EAGAIN
* to indicate that the vrele should not be done again. When
* this happens, we just return success. The correct thing to
* do would be to have all VOP_CLOSE instances do the vrele.
*/
if (error == EAGAIN)
return (0);
vrele(vp);
return (error);
}
/*
* Sequential heuristic - detect sequential operation
*/
static __inline
int
sequential_heuristic(struct uio *uio, struct file *fp)
{
if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
uio->uio_offset == fp->f_nextoff) {
/*
* XXX we assume that the filesystem block size is
* the default. Not true, but still gives us a pretty
* good indicator of how sequential the read operations
* are.
*/
fp->f_seqcount += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE;
if (fp->f_seqcount > IO_SEQMAX)
fp->f_seqcount = IO_SEQMAX;
return(fp->f_seqcount << IO_SEQSHIFT);
}
/*
* Not sequential, quick draw-down of seqcount
*/
if (fp->f_seqcount > 1)
fp->f_seqcount = 1;
else
fp->f_seqcount = 0;
return(0);
}
/*
* Package up an I/O request on a vnode into a uio and do it.
*/
int
vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, active_cred, file_cred,
aresid, td)
enum uio_rw rw;
struct vnode *vp;
caddr_t base;
int len;
off_t offset;
enum uio_seg segflg;
int ioflg;
struct ucred *active_cred;
struct ucred *file_cred;
int *aresid;
struct thread *td;
{
struct uio auio;
struct iovec aiov;
struct mount *mp;
struct ucred *cred;
int error;
GIANT_REQUIRED;
if ((ioflg & IO_NODELOCKED) == 0) {
mp = NULL;
if (rw == UIO_WRITE) {
if (vp->v_type != VCHR &&
(error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
!= 0)
return (error);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
} else {
/*
* XXX This should be LK_SHARED but I don't trust VFS
* enough to leave it like that until it has been
* reviewed further.
*/
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
}
}
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_segflg = segflg;
auio.uio_rw = rw;
auio.uio_td = td;
error = 0;
#ifdef MAC
if ((ioflg & IO_NOMACCHECK) == 0) {
if (rw == UIO_READ)
error = mac_check_vnode_read(active_cred, file_cred,
vp);
else
error = mac_check_vnode_write(active_cred, file_cred,
vp);
}
#endif
if (error == 0) {
if (file_cred)
cred = file_cred;
else
cred = active_cred;
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);
VOP_UNLOCK(vp, 0, td);
}
return (error);
}
/*
* Package up an I/O request on a vnode into a uio and do it. The I/O
* request is split up into smaller chunks and we try to avoid saturating
* the buffer cache while potentially holding a vnode locked, so we
* check bwillwrite() before calling vn_rdwr(). We also call uio_yield()
* to give other processes a chance to lock the vnode (either other processes
* core'ing the same binary, or unrelated processes scanning the directory).
*/
int
vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred,
file_cred, aresid, td)
enum uio_rw rw;
struct vnode *vp;
caddr_t base;
size_t len;
off_t offset;
enum uio_seg segflg;
int ioflg;
struct ucred *active_cred;
struct ucred *file_cred;
size_t *aresid;
struct thread *td;
{
int error = 0;
int iaresid;
GIANT_REQUIRED;
do {
int chunk;
/*
* Force `offset' to a multiple of MAXBSIZE except possibly
* for the first chunk, so that filesystems only need to
* write full blocks except possibly for the first and last
* chunks.
*/
chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
if (chunk > len)
chunk = len;
if (rw != UIO_READ && vp->v_type == VREG)
bwillwrite();
iaresid = 0;
error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
ioflg, active_cred, file_cred, &iaresid, td);
len -= chunk; /* aresid calc already includes length */
if (error)
break;
offset += chunk;
base += chunk;
uio_yield();
} while (len);
if (aresid)
*aresid = len + iaresid;
return (error);
}
/*
* File table vnode read routine.
*/
static int
vn_read(fp, uio, active_cred, flags, td)
struct file *fp;
struct uio *uio;
struct ucred *active_cred;
struct thread *td;
int flags;
{
struct vnode *vp;
int error, ioflag;
KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
uio->uio_td, td));
vp = fp->f_vnode;
ioflag = 0;
if (fp->f_flag & FNONBLOCK)
ioflag |= IO_NDELAY;
if (fp->f_flag & O_DIRECT)
ioflag |= IO_DIRECT;
mtx_lock(&Giant);
VOP_LEASE(vp, td, fp->f_cred, LEASE_READ);
/*
* According to McKusick the vn lock is protecting f_offset here.
* Once this field has it's own lock we can acquire this shared.
*/
if ((flags & FOF_OFFSET) == 0) {
vn_lock(vp, LK_EXCLUSIVE | LK_NOPAUSE | LK_RETRY, td);
uio->uio_offset = fp->f_offset;
} else
vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, td);
ioflag |= sequential_heuristic(uio, fp);
#ifdef MAC
error = mac_check_vnode_read(active_cred, fp->f_cred, vp);
if (error == 0)
#endif
error = VOP_READ(vp, uio, ioflag, fp->f_cred);
if ((flags & FOF_OFFSET) == 0)
fp->f_offset = uio->uio_offset;
fp->f_nextoff = uio->uio_offset;
VOP_UNLOCK(vp, 0, td);
mtx_unlock(&Giant);
return (error);
}
/*
* File table vnode write routine.
*/
static int
vn_write(fp, uio, active_cred, flags, td)
struct file *fp;
struct uio *uio;
struct ucred *active_cred;
struct thread *td;
int flags;
{
struct vnode *vp;
struct mount *mp;
int error, ioflag;
KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
uio->uio_td, td));
vp = fp->f_vnode;
mtx_lock(&Giant);
if (vp->v_type == VREG)
bwillwrite();
ioflag = IO_UNIT;
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 & O_DIRECT)
ioflag |= IO_DIRECT;
if ((fp->f_flag & O_FSYNC) ||
(vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
ioflag |= IO_SYNC;
mp = NULL;
if (vp->v_type != VCHR &&
(error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) {
mtx_unlock(&Giant);
return (error);
}
VOP_LEASE(vp, td, fp->f_cred, LEASE_WRITE);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
if ((flags & FOF_OFFSET) == 0)
uio->uio_offset = fp->f_offset;
ioflag |= sequential_heuristic(uio, fp);
#ifdef MAC
error = mac_check_vnode_write(active_cred, fp->f_cred, vp);
if (error == 0)
#endif
error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
if ((flags & FOF_OFFSET) == 0)
fp->f_offset = uio->uio_offset;
fp->f_nextoff = uio->uio_offset;
VOP_UNLOCK(vp, 0, td);
vn_finished_write(mp);
mtx_unlock(&Giant);
return (error);
}
/*
* File table vnode stat routine.
*/
static int
vn_statfile(fp, sb, active_cred, td)
struct file *fp;
struct stat *sb;
struct ucred *active_cred;
struct thread *td;
{
struct vnode *vp = fp->f_vnode;
int error;
mtx_lock(&Giant);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
VOP_UNLOCK(vp, 0, td);
mtx_unlock(&Giant);
return (error);
}
/*
* Stat a vnode; implementation for the stat syscall
*/
int
vn_stat(vp, sb, active_cred, file_cred, td)
struct vnode *vp;
register struct stat *sb;
struct ucred *active_cred;
struct ucred *file_cred;
struct thread *td;
{
struct vattr vattr;
register struct vattr *vap;
int error;
u_short mode;
GIANT_REQUIRED;
#ifdef MAC
error = mac_check_vnode_stat(active_cred, file_cred, vp);
if (error)
return (error);
#endif
vap = &vattr;
error = VOP_GETATTR(vp, vap, active_cred, td);
if (error)
return (error);
vp->v_cachedfs = vap->va_fsid;
vp->v_cachedid = vap->va_fileid;
/*
* Zero the spare stat fields
*/
bzero(sb, sizeof *sb);
/*
* Copy from vattr table
*/
if (vap->va_fsid != VNOVAL)
sb->st_dev = vap->va_fsid;
else
sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
sb->st_ino = vap->va_fileid;
mode = vap->va_mode;
switch (vap->va_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;
/* This is a cosmetic change, symlinks do not have a mode. */
if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW)
sb->st_mode &= ~ACCESSPERMS; /* 0000 */
else
sb->st_mode |= ACCESSPERMS; /* 0777 */
break;
case VSOCK:
mode |= S_IFSOCK;
break;
case VFIFO:
mode |= S_IFIFO;
break;
default:
return (EBADF);
};
sb->st_mode = mode;
sb->st_nlink = vap->va_nlink;
sb->st_uid = vap->va_uid;
sb->st_gid = vap->va_gid;
sb->st_rdev = vap->va_rdev;
if (vap->va_size > OFF_MAX)
return (EOVERFLOW);
sb->st_size = vap->va_size;
sb->st_atimespec = vap->va_atime;
sb->st_mtimespec = vap->va_mtime;
sb->st_ctimespec = vap->va_ctime;
sb->st_birthtimespec = vap->va_birthtime;
/*
* According to www.opengroup.org, the meaning of st_blksize is
* "a filesystem-specific preferred I/O block size for this
* object. In some filesystem types, this may vary from file
* to file"
* Default to PAGE_SIZE after much discussion.
*/
if (vap->va_type == VREG) {
sb->st_blksize = vap->va_blocksize;
} else if (vn_isdisk(vp, NULL)) {
sb->st_blksize = vp->v_rdev->si_bsize_best;
if (sb->st_blksize < vp->v_rdev->si_bsize_phys)
sb->st_blksize = vp->v_rdev->si_bsize_phys;
if (sb->st_blksize < BLKDEV_IOSIZE)
sb->st_blksize = BLKDEV_IOSIZE;
} else {
sb->st_blksize = PAGE_SIZE;
}
sb->st_flags = vap->va_flags;
if (suser(td))
sb->st_gen = 0;
else
sb->st_gen = vap->va_gen;
#if (S_BLKSIZE == 512)
/* Optimize this case */
sb->st_blocks = vap->va_bytes >> 9;
#else
sb->st_blocks = vap->va_bytes / S_BLKSIZE;
#endif
return (0);
}
/*
* File table vnode ioctl routine.
*/
static int
vn_ioctl(fp, com, data, active_cred, td)
struct file *fp;
u_long com;
void *data;
struct ucred *active_cred;
struct thread *td;
{
struct vnode *vp = fp->f_vnode;
struct vnode *vpold;
struct vattr vattr;
int error;
GIANT_REQUIRED;
switch (vp->v_type) {
case VREG:
case VDIR:
if (com == FIONREAD) {
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
error = VOP_GETATTR(vp, &vattr, active_cred, td);
VOP_UNLOCK(vp, 0, td);
if (error)
return (error);
*(int *)data = vattr.va_size - fp->f_offset;
return (0);
}
if (com == FIONBIO || com == FIOASYNC) /* XXX */
return (0); /* XXX */
/* FALLTHROUGH */
default:
#if 0
return (ENOTTY);
#endif
case VFIFO:
case VCHR:
case VBLK:
if (com == FIODTYPE) {
if (vp->v_type != VCHR && vp->v_type != VBLK)
return (ENOTTY);
*(int *)data = devsw(vp->v_rdev)->d_flags & D_TYPEMASK;
return (0);
}
error = VOP_IOCTL(vp, com, data, fp->f_flag, active_cred, td);
if (error == ENOIOCTL) {
#ifdef DIAGNOSTIC
kdb_enter("ENOIOCTL leaked through");
#endif
error = ENOTTY;
}
if (error == 0 && com == TIOCSCTTY) {
/* Do nothing if reassigning same control tty */
sx_slock(&proctree_lock);
if (td->td_proc->p_session->s_ttyvp == vp) {
sx_sunlock(&proctree_lock);
return (0);
}
vpold = td->td_proc->p_session->s_ttyvp;
VREF(vp);
SESS_LOCK(td->td_proc->p_session);
td->td_proc->p_session->s_ttyvp = vp;
SESS_UNLOCK(td->td_proc->p_session);
sx_sunlock(&proctree_lock);
/* Get rid of reference to old control tty */
if (vpold)
vrele(vpold);
}
return (error);
}
}
/*
* File table vnode poll routine.
*/
static int
vn_poll(fp, events, active_cred, td)
struct file *fp;
int events;
struct ucred *active_cred;
struct thread *td;
{
struct vnode *vp;
#ifdef MAC
int error;
#endif
GIANT_REQUIRED;
vp = fp->f_vnode;
#ifdef MAC
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
error = mac_check_vnode_poll(active_cred, fp->f_cred, vp);
VOP_UNLOCK(vp, 0, td);
if (error)
return (error);
#endif
return (VOP_POLL(vp, events, fp->f_cred, td));
}
/*
* Check that the vnode is still valid, and if so
* acquire requested lock.
*/
int
#ifndef DEBUG_LOCKS
vn_lock(vp, flags, td)
#else
debug_vn_lock(vp, flags, td, filename, line)
#endif
struct vnode *vp;
int flags;
struct thread *td;
#ifdef DEBUG_LOCKS
const char *filename;
int line;
#endif
{
int error;
do {
if ((flags & LK_INTERLOCK) == 0)
VI_LOCK(vp);
if ((vp->v_iflag & VI_XLOCK) && vp->v_vxthread != curthread) {
if ((flags & LK_NOWAIT) != 0) {
VI_UNLOCK(vp);
return (ENOENT);
}
vp->v_iflag |= VI_XWANT;
msleep(vp, VI_MTX(vp), PINOD, "vn_lock", 0);
if ((flags & LK_RETRY) == 0) {
VI_UNLOCK(vp);
return (ENOENT);
}
}
#ifdef DEBUG_LOCKS
vp->filename = filename;
vp->line = line;
#endif
/*
* lockmgr drops interlock before it will return for
* any reason. So force the code above to relock it.
*/
error = VOP_LOCK(vp, flags | LK_NOPAUSE | LK_INTERLOCK, td);
flags &= ~LK_INTERLOCK;
} while (flags & LK_RETRY && error != 0);
return (error);
}
/*
* File table vnode close routine.
*/
static int
vn_closefile(fp, td)
struct file *fp;
struct thread *td;
{
struct vnode *vp;
struct flock lf;
int error;
vp = fp->f_vnode;
mtx_lock(&Giant);
if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) {
lf.l_whence = SEEK_SET;
lf.l_start = 0;
lf.l_len = 0;
lf.l_type = F_UNLCK;
(void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
}
fp->f_ops = &badfileops;
error = vn_close(vp, fp->f_flag, fp->f_cred, td);
mtx_unlock(&Giant);
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.
*/
int
vn_start_write(vp, mpp, flags)
struct vnode *vp;
struct mount **mpp;
int flags;
{
struct mount *mp;
int error;
GIANT_REQUIRED;
/*
* If a vnode is provided, get and return the mount point that
* to which it will write.
*/
if (vp != NULL) {
if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
*mpp = NULL;
if (error != EOPNOTSUPP)
return (error);
return (0);
}
}
if ((mp = *mpp) == NULL)
return (0);
/*
* Check on status of suspension.
*/
while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
if (flags & V_NOWAIT)
return (EWOULDBLOCK);
error = tsleep(&mp->mnt_flag, (PUSER - 1) | (flags & PCATCH),
"suspfs", 0);
if (error)
return (error);
}
if (flags & V_XSLEEP)
return (0);
mp->mnt_writeopcount++;
return (0);
}
/*
* Secondary suspension. Used by operations such as vop_inactive
* routines that are needed by the higher level functions. These
* are allowed to proceed until all the higher level functions have
* completed (indicated by mnt_writeopcount dropping to zero). At that
* time, these operations are halted until the suspension is over.
*/
int
vn_write_suspend_wait(vp, mp, flags)
struct vnode *vp;
struct mount *mp;
int flags;
{
int error;
GIANT_REQUIRED;
if (vp != NULL) {
if ((error = VOP_GETWRITEMOUNT(vp, &mp)) != 0) {
if (error != EOPNOTSUPP)
return (error);
return (0);
}
}
/*
* If we are not suspended or have not yet reached suspended
* mode, then let the operation proceed.
*/
if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPENDED) == 0)
return (0);
if (flags & V_NOWAIT)
return (EWOULDBLOCK);
/*
* Wait for the suspension to finish.
*/
return (tsleep(&mp->mnt_flag, (PUSER - 1) | (flags & PCATCH),
"suspfs", 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(mp)
struct mount *mp;
{
GIANT_REQUIRED;
if (mp == NULL)
return;
mp->mnt_writeopcount--;
if (mp->mnt_writeopcount < 0)
panic("vn_finished_write: neg cnt");
if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
mp->mnt_writeopcount <= 0)
wakeup(&mp->mnt_writeopcount);
}
/*
* Request a filesystem to suspend write operations.
*/
int
vfs_write_suspend(mp)
struct mount *mp;
{
struct thread *td = curthread;
int error;
GIANT_REQUIRED;
if (mp->mnt_kern_flag & MNTK_SUSPEND)
return (0);
mp->mnt_kern_flag |= MNTK_SUSPEND;
if (mp->mnt_writeopcount > 0)
(void) tsleep(&mp->mnt_writeopcount, PUSER - 1, "suspwt", 0);
if ((error = VFS_SYNC(mp, MNT_WAIT, td->td_ucred, td)) != 0) {
vfs_write_resume(mp);
return (error);
}
mp->mnt_kern_flag |= MNTK_SUSPENDED;
return (0);
}
/*
* Request a filesystem to resume write operations.
*/
void
vfs_write_resume(mp)
struct mount *mp;
{
GIANT_REQUIRED;
if ((mp->mnt_kern_flag & MNTK_SUSPEND) == 0)
return;
mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPENDED);
wakeup(&mp->mnt_writeopcount);
wakeup(&mp->mnt_flag);
}
/*
* Implement kqueues for files by translating it to vnode operation.
*/
static int
vn_kqfilter(struct file *fp, struct knote *kn)
{
int error;
mtx_lock(&Giant);
error = VOP_KQFILTER(fp->f_vnode, kn);
mtx_unlock(&Giant);
return error;
}
/*
* Simplified in-kernel wrapper calls for extended attribute access.
* Both calls pass in a NULL credential, authorizing as "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, int *buflen, char *buf, struct thread *td)
{
struct uio auio;
struct iovec iov;
int error;
iov.iov_len = *buflen;
iov.iov_base = buf;
auio.uio_iov = &iov;
auio.uio_iovcnt = 1;
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_td = td;
auio.uio_offset = 0;
auio.uio_resid = *buflen;
if ((ioflg & IO_NODELOCKED) == 0)
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
/* authorize attribute retrieval as kernel */
error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
td);
if ((ioflg & IO_NODELOCKED) == 0)
VOP_UNLOCK(vp, 0, td);
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, int buflen, char *buf, struct thread *td)
{
struct uio auio;
struct iovec iov;
struct mount *mp;
int error;
iov.iov_len = buflen;
iov.iov_base = buf;
auio.uio_iov = &iov;
auio.uio_iovcnt = 1;
auio.uio_rw = UIO_WRITE;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_td = td;
auio.uio_offset = 0;
auio.uio_resid = buflen;
if ((ioflg & IO_NODELOCKED) == 0) {
if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
return (error);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
}
/* authorize attribute setting as kernel */
error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
if ((ioflg & IO_NODELOCKED) == 0) {
vn_finished_write(mp);
VOP_UNLOCK(vp, 0, td);
}
return (error);
}
int
vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
const char *attrname, struct thread *td)
{
struct mount *mp;
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, td);
}
/* authorize attribute removal as kernel */
error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
if (error == EOPNOTSUPP)
error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
NULL, td);
if ((ioflg & IO_NODELOCKED) == 0) {
vn_finished_write(mp);
VOP_UNLOCK(vp, 0, td);
}
return (error);
}