dbb3ec5ce3
used to ensure that we weren't exiting the syscall with a lock still held. This wasn't safe, however, because we'd already executed a vput() and on a loaded system the vnode may have been free'd by the time we assert. This functionality is also handled by the td_locks assert in userret, which doesn't tell you what the syscall was, but will at least panic before you deadlock. Sponsored by: Isilon Systems, Inc. Discovred by: Peter Holm Approved by: re (blanket vfs)
1162 lines
26 KiB
C
1162 lines
26 KiB
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("$FreeBSD$");
|
|
|
|
#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;
|
|
int vfslocked;
|
|
|
|
restart:
|
|
vfslocked = 0;
|
|
fmode = *flagp;
|
|
if (fmode & O_CREAT) {
|
|
ndp->ni_cnd.cn_nameiop = CREATE;
|
|
ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | MPSAFE;
|
|
if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
|
|
ndp->ni_cnd.cn_flags |= FOLLOW;
|
|
bwillwrite();
|
|
if ((error = namei(ndp)) != 0)
|
|
return (error);
|
|
vfslocked = (ndp->ni_cnd.cn_flags & GIANTHELD) != 0;
|
|
ndp->ni_cnd.cn_flags &= ~MPSAFE;
|
|
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);
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
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);
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|
error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
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|
&ndp->ni_cnd, vap);
|
|
#ifdef MAC
|
|
}
|
|
#endif
|
|
vput(ndp->ni_dvp);
|
|
vn_finished_write(mp);
|
|
if (error) {
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
NDFREE(ndp, NDF_ONLY_PNBUF);
|
|
return (error);
|
|
}
|
|
fmode &= ~O_TRUNC;
|
|
vp = ndp->ni_vp;
|
|
} else {
|
|
if (ndp->ni_dvp == ndp->ni_vp)
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|
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 = ISOPEN |
|
|
((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) |
|
|
LOCKSHARED | LOCKLEAF | MPSAFE;
|
|
if ((error = namei(ndp)) != 0)
|
|
return (error);
|
|
ndp->ni_cnd.cn_flags &= ~MPSAFE;
|
|
vfslocked = (ndp->ni_cnd.cn_flags & GIANTHELD) != 0;
|
|
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_OPEN(vp, fmode, cred, td, fdidx)) != 0)
|
|
goto bad;
|
|
|
|
if (fmode & FWRITE)
|
|
vp->v_writecount++;
|
|
*flagp = fmode;
|
|
ASSERT_VOP_LOCKED(vp, "vn_open_cred");
|
|
if (fdidx == -1)
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
return (0);
|
|
bad:
|
|
NDFREE(ndp, NDF_ONLY_PNBUF);
|
|
vput(vp);
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
*flagp = fmode;
|
|
ndp->ni_vp = NULL;
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Check for write permissions on the specified vnode.
|
|
* Prototype text segments cannot be written.
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|
*/
|
|
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;
|
|
{
|
|
struct mount *mp;
|
|
int error;
|
|
|
|
VFS_ASSERT_GIANT(vp->v_mount);
|
|
|
|
vn_start_write(vp, &mp, V_WAIT);
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
if (flags & FWRITE)
|
|
vp->v_writecount--;
|
|
error = VOP_CLOSE(vp, flags, file_cred, td);
|
|
vput(vp);
|
|
vn_finished_write(mp);
|
|
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;
|
|
|
|
VFS_ASSERT_GIANT(vp->v_mount);
|
|
|
|
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);
|
|
}
|
|
|
|
}
|
|
ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
|
|
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;
|
|
|
|
VFS_ASSERT_GIANT(vp->v_mount);
|
|
|
|
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;
|
|
int vfslocked;
|
|
|
|
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;
|
|
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
|
|
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_RETRY, td);
|
|
uio->uio_offset = fp->f_offset;
|
|
} else
|
|
vn_lock(vp, LK_SHARED | 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);
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
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;
|
|
int vfslocked;
|
|
|
|
KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
|
|
uio->uio_td, td));
|
|
vp = fp->f_vnode;
|
|
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
|
|
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)
|
|
goto unlock;
|
|
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);
|
|
unlock:
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
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 vfslocked;
|
|
int error;
|
|
|
|
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
|
|
VOP_UNLOCK(vp, 0, td);
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
|
|
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;
|
|
|
|
#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);
|
|
|
|
/*
|
|
* 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.
|
|
* XXX: min(PAGE_SIZE, vp->v_bufobj.bo_bsize) may be more correct.
|
|
*/
|
|
|
|
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 vattr vattr;
|
|
int vfslocked;
|
|
int error;
|
|
|
|
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
|
|
error = ENOTTY;
|
|
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)
|
|
*(int *)data = vattr.va_size - fp->f_offset;
|
|
}
|
|
if (com == FIONBIO || com == FIOASYNC) /* XXX */
|
|
error = 0;
|
|
else
|
|
error = VOP_IOCTL(vp, com, data, fp->f_flag,
|
|
active_cred, td);
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
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;
|
|
int error;
|
|
|
|
mtx_lock(&Giant);
|
|
|
|
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)
|
|
#endif
|
|
|
|
error = VOP_POLL(vp, events, fp->f_cred, td);
|
|
mtx_unlock(&Giant);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* 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 ((flags & LK_NOWAIT || (flags & LK_TYPE_MASK) == 0) &&
|
|
vp->v_iflag & VI_DOOMED) {
|
|
VI_UNLOCK(vp);
|
|
return (ENOENT);
|
|
}
|
|
/*
|
|
* Just polling to check validity.
|
|
*/
|
|
if ((flags & LK_TYPE_MASK) == 0) {
|
|
VI_UNLOCK(vp);
|
|
return (0);
|
|
}
|
|
#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_INTERLOCK, td);
|
|
flags &= ~LK_INTERLOCK;
|
|
KASSERT((flags & LK_RETRY) == 0 || error == 0,
|
|
("LK_RETRY set with incompatible flags %d\n", flags));
|
|
/*
|
|
* Callers specify LK_RETRY if they wish to get dead vnodes.
|
|
* If RETRY is not set, we return ENOENT instead.
|
|
*/
|
|
if (error == 0 && vp->v_iflag & VI_DOOMED &&
|
|
(flags & LK_RETRY) == 0) {
|
|
VOP_UNLOCK(vp, 0, td);
|
|
error = ENOENT;
|
|
break;
|
|
}
|
|
} 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 vfslocked;
|
|
int error;
|
|
|
|
vp = fp->f_vnode;
|
|
|
|
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
|
|
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);
|
|
VFS_UNLOCK_GIANT(vfslocked);
|
|
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;
|
|
|
|
error = 0;
|
|
/*
|
|
* 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);
|
|
MNT_ILOCK(mp);
|
|
/*
|
|
* Check on status of suspension.
|
|
*/
|
|
while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
|
|
if (flags & V_NOWAIT) {
|
|
error = EWOULDBLOCK;
|
|
goto unlock;
|
|
}
|
|
error = msleep(&mp->mnt_flag, MNT_MTX(mp),
|
|
(PUSER - 1) | (flags & PCATCH), "suspfs", 0);
|
|
if (error)
|
|
goto unlock;
|
|
}
|
|
if (flags & V_XSLEEP)
|
|
goto unlock;
|
|
mp->mnt_writeopcount++;
|
|
unlock:
|
|
MNT_IUNLOCK(mp);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
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)
|
|
return (0);
|
|
MNT_ILOCK(mp);
|
|
if ((mp->mnt_kern_flag & MNTK_SUSPENDED) == 0) {
|
|
MNT_IUNLOCK(mp);
|
|
return (0);
|
|
}
|
|
if (flags & V_NOWAIT) {
|
|
MNT_IUNLOCK(mp);
|
|
return (EWOULDBLOCK);
|
|
}
|
|
/*
|
|
* Wait for the suspension to finish.
|
|
*/
|
|
return (msleep(&mp->mnt_flag, MNT_MTX(mp),
|
|
(PUSER - 1) | (flags & PCATCH) | PDROP, "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;
|
|
{
|
|
if (mp == NULL)
|
|
return;
|
|
MNT_ILOCK(mp);
|
|
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);
|
|
MNT_IUNLOCK(mp);
|
|
}
|
|
|
|
/*
|
|
* Request a filesystem to suspend write operations.
|
|
*/
|
|
int
|
|
vfs_write_suspend(mp)
|
|
struct mount *mp;
|
|
{
|
|
struct thread *td = curthread;
|
|
int error;
|
|
|
|
error = 0;
|
|
MNT_ILOCK(mp);
|
|
if (mp->mnt_kern_flag & MNTK_SUSPEND)
|
|
goto unlock;
|
|
mp->mnt_kern_flag |= MNTK_SUSPEND;
|
|
if (mp->mnt_writeopcount > 0)
|
|
(void) msleep(&mp->mnt_writeopcount,
|
|
MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
|
|
else
|
|
MNT_IUNLOCK(mp);
|
|
if ((error = VFS_SYNC(mp, MNT_WAIT, td)) != 0) {
|
|
vfs_write_resume(mp);
|
|
return (error);
|
|
}
|
|
MNT_ILOCK(mp);
|
|
mp->mnt_kern_flag |= MNTK_SUSPENDED;
|
|
unlock:
|
|
MNT_IUNLOCK(mp);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Request a filesystem to resume write operations.
|
|
*/
|
|
void
|
|
vfs_write_resume(mp)
|
|
struct mount *mp;
|
|
{
|
|
|
|
MNT_ILOCK(mp);
|
|
if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
|
|
mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPENDED);
|
|
wakeup(&mp->mnt_writeopcount);
|
|
wakeup(&mp->mnt_flag);
|
|
}
|
|
MNT_IUNLOCK(mp);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
|
|
|
|
/* 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);
|
|
}
|
|
|
|
ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
|
|
|
|
/* 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);
|
|
}
|
|
|
|
ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
|
|
|
|
/* 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);
|
|
}
|