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freebsd-dev/sys/kern/vfs_default.c
Mateusz Guzik d245aa1e72 vfs: apply r352437 to the fast path as well 
This one is very hard to run into. If the filesystem is being unmounted or
the mount point is freed the vfs_op_thread_enter will fail. For it to
succeed the mount point itself would have to be reallocated in the time
window between the initial read and the attempt to enter.

Sponsored by:	The FreeBSD Foundation
2019-09-17 15:53:40 +00:00

1409 lines
29 KiB
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed
* to Berkeley by John Heidemann of the UCLA Ficus project.
*
* Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/event.h>
#include <sys/filio.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/lockf.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/rwlock.h>
#include <sys/fcntl.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <sys/dirent.h>
#include <sys/poll.h>
#include <security/mac/mac_framework.h>
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vnode_pager.h>
static int vop_nolookup(struct vop_lookup_args *);
static int vop_norename(struct vop_rename_args *);
static int vop_nostrategy(struct vop_strategy_args *);
static int get_next_dirent(struct vnode *vp, struct dirent **dpp,
char *dirbuf, int dirbuflen, off_t *off,
char **cpos, int *len, int *eofflag,
struct thread *td);
static int dirent_exists(struct vnode *vp, const char *dirname,
struct thread *td);
#define DIRENT_MINSIZE (sizeof(struct dirent) - (MAXNAMLEN+1) + 4)
static int vop_stdis_text(struct vop_is_text_args *ap);
static int vop_stdunset_text(struct vop_unset_text_args *ap);
static int vop_stdadd_writecount(struct vop_add_writecount_args *ap);
static int vop_stdcopy_file_range(struct vop_copy_file_range_args *ap);
static int vop_stdfdatasync(struct vop_fdatasync_args *ap);
static int vop_stdgetpages_async(struct vop_getpages_async_args *ap);
static int vop_stdioctl(struct vop_ioctl_args *ap);
/*
* This vnode table stores what we want to do if the filesystem doesn't
* implement a particular VOP.
*
* If there is no specific entry here, we will return EOPNOTSUPP.
*
* Note that every filesystem has to implement either vop_access
* or vop_accessx; failing to do so will result in immediate crash
* due to stack overflow, as vop_stdaccess() calls vop_stdaccessx(),
* which calls vop_stdaccess() etc.
*/
struct vop_vector default_vnodeops = {
.vop_default = NULL,
.vop_bypass = VOP_EOPNOTSUPP,
.vop_access = vop_stdaccess,
.vop_accessx = vop_stdaccessx,
.vop_advise = vop_stdadvise,
.vop_advlock = vop_stdadvlock,
.vop_advlockasync = vop_stdadvlockasync,
.vop_advlockpurge = vop_stdadvlockpurge,
.vop_allocate = vop_stdallocate,
.vop_bmap = vop_stdbmap,
.vop_close = VOP_NULL,
.vop_fsync = VOP_NULL,
.vop_fdatasync = vop_stdfdatasync,
.vop_getpages = vop_stdgetpages,
.vop_getpages_async = vop_stdgetpages_async,
.vop_getwritemount = vop_stdgetwritemount,
.vop_inactive = VOP_NULL,
.vop_need_inactive = vop_stdneed_inactive,
.vop_ioctl = vop_stdioctl,
.vop_kqfilter = vop_stdkqfilter,
.vop_islocked = vop_stdislocked,
.vop_lock1 = vop_stdlock,
.vop_lookup = vop_nolookup,
.vop_open = VOP_NULL,
.vop_pathconf = VOP_EINVAL,
.vop_poll = vop_nopoll,
.vop_putpages = vop_stdputpages,
.vop_readlink = VOP_EINVAL,
.vop_rename = vop_norename,
.vop_revoke = VOP_PANIC,
.vop_strategy = vop_nostrategy,
.vop_unlock = vop_stdunlock,
.vop_vptocnp = vop_stdvptocnp,
.vop_vptofh = vop_stdvptofh,
.vop_unp_bind = vop_stdunp_bind,
.vop_unp_connect = vop_stdunp_connect,
.vop_unp_detach = vop_stdunp_detach,
.vop_is_text = vop_stdis_text,
.vop_set_text = vop_stdset_text,
.vop_unset_text = vop_stdunset_text,
.vop_add_writecount = vop_stdadd_writecount,
.vop_copy_file_range = vop_stdcopy_file_range,
};
/*
* Series of placeholder functions for various error returns for
* VOPs.
*/
int
vop_eopnotsupp(struct vop_generic_args *ap)
{
/*
printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name);
*/
return (EOPNOTSUPP);
}
int
vop_ebadf(struct vop_generic_args *ap)
{
return (EBADF);
}
int
vop_enotty(struct vop_generic_args *ap)
{
return (ENOTTY);
}
int
vop_einval(struct vop_generic_args *ap)
{
return (EINVAL);
}
int
vop_enoent(struct vop_generic_args *ap)
{
return (ENOENT);
}
int
vop_null(struct vop_generic_args *ap)
{
return (0);
}
/*
* Helper function to panic on some bad VOPs in some filesystems.
*/
int
vop_panic(struct vop_generic_args *ap)
{
panic("filesystem goof: vop_panic[%s]", ap->a_desc->vdesc_name);
}
/*
* vop_std<something> and vop_no<something> are default functions for use by
* filesystems that need the "default reasonable" implementation for a
* particular operation.
*
* The documentation for the operations they implement exists (if it exists)
* in the VOP_<SOMETHING>(9) manpage (all uppercase).
*/
/*
* Default vop for filesystems that do not support name lookup
*/
static int
vop_nolookup(ap)
struct vop_lookup_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
} */ *ap;
{
*ap->a_vpp = NULL;
return (ENOTDIR);
}
/*
* vop_norename:
*
* Handle unlock and reference counting for arguments of vop_rename
* for filesystems that do not implement rename operation.
*/
static int
vop_norename(struct vop_rename_args *ap)
{
vop_rename_fail(ap);
return (EOPNOTSUPP);
}
/*
* vop_nostrategy:
*
* Strategy routine for VFS devices that have none.
*
* BIO_ERROR and B_INVAL must be cleared prior to calling any strategy
* routine. Typically this is done for a BIO_READ strategy call.
* Typically B_INVAL is assumed to already be clear prior to a write
* and should not be cleared manually unless you just made the buffer
* invalid. BIO_ERROR should be cleared either way.
*/
static int
vop_nostrategy (struct vop_strategy_args *ap)
{
printf("No strategy for buffer at %p\n", ap->a_bp);
vn_printf(ap->a_vp, "vnode ");
ap->a_bp->b_ioflags |= BIO_ERROR;
ap->a_bp->b_error = EOPNOTSUPP;
bufdone(ap->a_bp);
return (EOPNOTSUPP);
}
static int
get_next_dirent(struct vnode *vp, struct dirent **dpp, char *dirbuf,
int dirbuflen, off_t *off, char **cpos, int *len,
int *eofflag, struct thread *td)
{
int error, reclen;
struct uio uio;
struct iovec iov;
struct dirent *dp;
KASSERT(VOP_ISLOCKED(vp), ("vp %p is not locked", vp));
KASSERT(vp->v_type == VDIR, ("vp %p is not a directory", vp));
if (*len == 0) {
iov.iov_base = dirbuf;
iov.iov_len = dirbuflen;
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = *off;
uio.uio_resid = dirbuflen;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_rw = UIO_READ;
uio.uio_td = td;
*eofflag = 0;
#ifdef MAC
error = mac_vnode_check_readdir(td->td_ucred, vp);
if (error == 0)
#endif
error = VOP_READDIR(vp, &uio, td->td_ucred, eofflag,
NULL, NULL);
if (error)
return (error);
*off = uio.uio_offset;
*cpos = dirbuf;
*len = (dirbuflen - uio.uio_resid);
if (*len == 0)
return (ENOENT);
}
dp = (struct dirent *)(*cpos);
reclen = dp->d_reclen;
*dpp = dp;
/* check for malformed directory.. */
if (reclen < DIRENT_MINSIZE)
return (EINVAL);
*cpos += reclen;
*len -= reclen;
return (0);
}
/*
* Check if a named file exists in a given directory vnode.
*/
static int
dirent_exists(struct vnode *vp, const char *dirname, struct thread *td)
{
char *dirbuf, *cpos;
int error, eofflag, dirbuflen, len, found;
off_t off;
struct dirent *dp;
struct vattr va;
KASSERT(VOP_ISLOCKED(vp), ("vp %p is not locked", vp));
KASSERT(vp->v_type == VDIR, ("vp %p is not a directory", vp));
found = 0;
error = VOP_GETATTR(vp, &va, td->td_ucred);
if (error)
return (found);
dirbuflen = DEV_BSIZE;
if (dirbuflen < va.va_blocksize)
dirbuflen = va.va_blocksize;
dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
off = 0;
len = 0;
do {
error = get_next_dirent(vp, &dp, dirbuf, dirbuflen, &off,
&cpos, &len, &eofflag, td);
if (error)
goto out;
if (dp->d_type != DT_WHT && dp->d_fileno != 0 &&
strcmp(dp->d_name, dirname) == 0) {
found = 1;
goto out;
}
} while (len > 0 || !eofflag);
out:
free(dirbuf, M_TEMP);
return (found);
}
int
vop_stdaccess(struct vop_access_args *ap)
{
KASSERT((ap->a_accmode & ~(VEXEC | VWRITE | VREAD | VADMIN |
VAPPEND)) == 0, ("invalid bit in accmode"));
return (VOP_ACCESSX(ap->a_vp, ap->a_accmode, ap->a_cred, ap->a_td));
}
int
vop_stdaccessx(struct vop_accessx_args *ap)
{
int error;
accmode_t accmode = ap->a_accmode;
error = vfs_unixify_accmode(&accmode);
if (error != 0)
return (error);
if (accmode == 0)
return (0);
return (VOP_ACCESS(ap->a_vp, accmode, ap->a_cred, ap->a_td));
}
/*
* Advisory record locking support
*/
int
vop_stdadvlock(struct vop_advlock_args *ap)
{
struct vnode *vp;
struct vattr vattr;
int error;
vp = ap->a_vp;
if (ap->a_fl->l_whence == SEEK_END) {
/*
* The NFSv4 server must avoid doing a vn_lock() here, since it
* can deadlock the nfsd threads, due to a LOR. Fortunately
* the NFSv4 server always uses SEEK_SET and this code is
* only required for the SEEK_END case.
*/
vn_lock(vp, LK_SHARED | LK_RETRY);
error = VOP_GETATTR(vp, &vattr, curthread->td_ucred);
VOP_UNLOCK(vp, 0);
if (error)
return (error);
} else
vattr.va_size = 0;
return (lf_advlock(ap, &(vp->v_lockf), vattr.va_size));
}
int
vop_stdadvlockasync(struct vop_advlockasync_args *ap)
{
struct vnode *vp;
struct vattr vattr;
int error;
vp = ap->a_vp;
if (ap->a_fl->l_whence == SEEK_END) {
/* The size argument is only needed for SEEK_END. */
vn_lock(vp, LK_SHARED | LK_RETRY);
error = VOP_GETATTR(vp, &vattr, curthread->td_ucred);
VOP_UNLOCK(vp, 0);
if (error)
return (error);
} else
vattr.va_size = 0;
return (lf_advlockasync(ap, &(vp->v_lockf), vattr.va_size));
}
int
vop_stdadvlockpurge(struct vop_advlockpurge_args *ap)
{
struct vnode *vp;
vp = ap->a_vp;
lf_purgelocks(vp, &vp->v_lockf);
return (0);
}
/*
* vop_stdpathconf:
*
* Standard implementation of POSIX pathconf, to get information about limits
* for a filesystem.
* Override per filesystem for the case where the filesystem has smaller
* limits.
*/
int
vop_stdpathconf(ap)
struct vop_pathconf_args /* {
struct vnode *a_vp;
int a_name;
int *a_retval;
} */ *ap;
{
switch (ap->a_name) {
case _PC_ASYNC_IO:
*ap->a_retval = _POSIX_ASYNCHRONOUS_IO;
return (0);
case _PC_PATH_MAX:
*ap->a_retval = PATH_MAX;
return (0);
case _PC_ACL_EXTENDED:
case _PC_ACL_NFS4:
case _PC_CAP_PRESENT:
case _PC_INF_PRESENT:
case _PC_MAC_PRESENT:
*ap->a_retval = 0;
return (0);
default:
return (EINVAL);
}
/* NOTREACHED */
}
/*
* Standard lock, unlock and islocked functions.
*/
int
vop_stdlock(ap)
struct vop_lock1_args /* {
struct vnode *a_vp;
int a_flags;
char *file;
int line;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct mtx *ilk;
ilk = VI_MTX(vp);
return (lockmgr_lock_fast_path(vp->v_vnlock, ap->a_flags,
&ilk->lock_object, ap->a_file, ap->a_line));
}
/* See above. */
int
vop_stdunlock(ap)
struct vop_unlock_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct mtx *ilk;
ilk = VI_MTX(vp);
return (lockmgr_unlock_fast_path(vp->v_vnlock, ap->a_flags,
&ilk->lock_object));
}
/* See above. */
int
vop_stdislocked(ap)
struct vop_islocked_args /* {
struct vnode *a_vp;
} */ *ap;
{
return (lockstatus(ap->a_vp->v_vnlock));
}
/*
* Return true for select/poll.
*/
int
vop_nopoll(ap)
struct vop_poll_args /* {
struct vnode *a_vp;
int a_events;
struct ucred *a_cred;
struct thread *a_td;
} */ *ap;
{
return (poll_no_poll(ap->a_events));
}
/*
* Implement poll for local filesystems that support it.
*/
int
vop_stdpoll(ap)
struct vop_poll_args /* {
struct vnode *a_vp;
int a_events;
struct ucred *a_cred;
struct thread *a_td;
} */ *ap;
{
if (ap->a_events & ~POLLSTANDARD)
return (vn_pollrecord(ap->a_vp, ap->a_td, ap->a_events));
return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
}
/*
* Return our mount point, as we will take charge of the writes.
*/
int
vop_stdgetwritemount(ap)
struct vop_getwritemount_args /* {
struct vnode *a_vp;
struct mount **a_mpp;
} */ *ap;
{
struct mount *mp;
struct vnode *vp;
/*
* Note that having a reference does not prevent forced unmount from
* setting ->v_mount to NULL after the lock gets released. This is of
* no consequence for typical consumers (most notably vn_start_write)
* since in this case the vnode is VI_DOOMED. Unmount might have
* progressed far enough that its completion is only delayed by the
* reference obtained here. The consumer only needs to concern itself
* with releasing it.
*/
vp = ap->a_vp;
mp = vp->v_mount;
if (mp == NULL) {
*(ap->a_mpp) = NULL;
return (0);
}
if (vfs_op_thread_enter(mp)) {
if (mp == vp->v_mount) {
vfs_mp_count_add_pcpu(mp, ref, 1);
vfs_op_thread_exit(mp);
} else {
vfs_op_thread_exit(mp);
mp = NULL;
}
} else {
MNT_ILOCK(mp);
if (mp == vp->v_mount) {
MNT_REF(mp);
MNT_IUNLOCK(mp);
} else {
MNT_IUNLOCK(mp);
mp = NULL;
}
}
*(ap->a_mpp) = mp;
return (0);
}
/*
* If the file system doesn't implement VOP_BMAP, then return sensible defaults:
* - Return the vnode's bufobj instead of any underlying device's bufobj
* - Calculate the physical block number as if there were equal size
* consecutive blocks, but
* - Report no contiguous runs of blocks.
*/
int
vop_stdbmap(ap)
struct vop_bmap_args /* {
struct vnode *a_vp;
daddr_t a_bn;
struct bufobj **a_bop;
daddr_t *a_bnp;
int *a_runp;
int *a_runb;
} */ *ap;
{
if (ap->a_bop != NULL)
*ap->a_bop = &ap->a_vp->v_bufobj;
if (ap->a_bnp != NULL)
*ap->a_bnp = ap->a_bn * btodb(ap->a_vp->v_mount->mnt_stat.f_iosize);
if (ap->a_runp != NULL)
*ap->a_runp = 0;
if (ap->a_runb != NULL)
*ap->a_runb = 0;
return (0);
}
int
vop_stdfsync(ap)
struct vop_fsync_args /* {
struct vnode *a_vp;
int a_waitfor;
struct thread *a_td;
} */ *ap;
{
return (vn_fsync_buf(ap->a_vp, ap->a_waitfor));
}
static int
vop_stdfdatasync(struct vop_fdatasync_args *ap)
{
return (VOP_FSYNC(ap->a_vp, MNT_WAIT, ap->a_td));
}
int
vop_stdfdatasync_buf(struct vop_fdatasync_args *ap)
{
return (vn_fsync_buf(ap->a_vp, MNT_WAIT));
}
/* XXX Needs good comment and more info in the manpage (VOP_GETPAGES(9)). */
int
vop_stdgetpages(ap)
struct vop_getpages_args /* {
struct vnode *a_vp;
vm_page_t *a_m;
int a_count;
int *a_rbehind;
int *a_rahead;
} */ *ap;
{
return vnode_pager_generic_getpages(ap->a_vp, ap->a_m,
ap->a_count, ap->a_rbehind, ap->a_rahead, NULL, NULL);
}
static int
vop_stdgetpages_async(struct vop_getpages_async_args *ap)
{
int error;
error = VOP_GETPAGES(ap->a_vp, ap->a_m, ap->a_count, ap->a_rbehind,
ap->a_rahead);
ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error);
return (error);
}
int
vop_stdkqfilter(struct vop_kqfilter_args *ap)
{
return vfs_kqfilter(ap);
}
/* XXX Needs good comment and more info in the manpage (VOP_PUTPAGES(9)). */
int
vop_stdputpages(ap)
struct vop_putpages_args /* {
struct vnode *a_vp;
vm_page_t *a_m;
int a_count;
int a_sync;
int *a_rtvals;
} */ *ap;
{
return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
ap->a_sync, ap->a_rtvals);
}
int
vop_stdvptofh(struct vop_vptofh_args *ap)
{
return (EOPNOTSUPP);
}
int
vop_stdvptocnp(struct vop_vptocnp_args *ap)
{
struct vnode *vp = ap->a_vp;
struct vnode **dvp = ap->a_vpp;
struct ucred *cred = ap->a_cred;
char *buf = ap->a_buf;
int *buflen = ap->a_buflen;
char *dirbuf, *cpos;
int i, error, eofflag, dirbuflen, flags, locked, len, covered;
off_t off;
ino_t fileno;
struct vattr va;
struct nameidata nd;
struct thread *td;
struct dirent *dp;
struct vnode *mvp;
i = *buflen;
error = 0;
covered = 0;
td = curthread;
if (vp->v_type != VDIR)
return (ENOENT);
error = VOP_GETATTR(vp, &va, cred);
if (error)
return (error);
VREF(vp);
locked = VOP_ISLOCKED(vp);
VOP_UNLOCK(vp, 0);
NDINIT_ATVP(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, UIO_SYSSPACE,
"..", vp, td);
flags = FREAD;
error = vn_open_cred(&nd, &flags, 0, VN_OPEN_NOAUDIT, cred, NULL);
if (error) {
vn_lock(vp, locked | LK_RETRY);
return (error);
}
NDFREE(&nd, NDF_ONLY_PNBUF);
mvp = *dvp = nd.ni_vp;
if (vp->v_mount != (*dvp)->v_mount &&
((*dvp)->v_vflag & VV_ROOT) &&
((*dvp)->v_mount->mnt_flag & MNT_UNION)) {
*dvp = (*dvp)->v_mount->mnt_vnodecovered;
VREF(mvp);
VOP_UNLOCK(mvp, 0);
vn_close(mvp, FREAD, cred, td);
VREF(*dvp);
vn_lock(*dvp, LK_SHARED | LK_RETRY);
covered = 1;
}
fileno = va.va_fileid;
dirbuflen = DEV_BSIZE;
if (dirbuflen < va.va_blocksize)
dirbuflen = va.va_blocksize;
dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
if ((*dvp)->v_type != VDIR) {
error = ENOENT;
goto out;
}
off = 0;
len = 0;
do {
/* call VOP_READDIR of parent */
error = get_next_dirent(*dvp, &dp, dirbuf, dirbuflen, &off,
&cpos, &len, &eofflag, td);
if (error)
goto out;
if ((dp->d_type != DT_WHT) &&
(dp->d_fileno == fileno)) {
if (covered) {
VOP_UNLOCK(*dvp, 0);
vn_lock(mvp, LK_SHARED | LK_RETRY);
if (dirent_exists(mvp, dp->d_name, td)) {
error = ENOENT;
VOP_UNLOCK(mvp, 0);
vn_lock(*dvp, LK_SHARED | LK_RETRY);
goto out;
}
VOP_UNLOCK(mvp, 0);
vn_lock(*dvp, LK_SHARED | LK_RETRY);
}
i -= dp->d_namlen;
if (i < 0) {
error = ENOMEM;
goto out;
}
if (dp->d_namlen == 1 && dp->d_name[0] == '.') {
error = ENOENT;
} else {
bcopy(dp->d_name, buf + i, dp->d_namlen);
error = 0;
}
goto out;
}
} while (len > 0 || !eofflag);
error = ENOENT;
out:
free(dirbuf, M_TEMP);
if (!error) {
*buflen = i;
vref(*dvp);
}
if (covered) {
vput(*dvp);
vrele(mvp);
} else {
VOP_UNLOCK(mvp, 0);
vn_close(mvp, FREAD, cred, td);
}
vn_lock(vp, locked | LK_RETRY);
return (error);
}
int
vop_stdallocate(struct vop_allocate_args *ap)
{
#ifdef __notyet__
struct statfs *sfs;
off_t maxfilesize = 0;
#endif
struct iovec aiov;
struct vattr vattr, *vap;
struct uio auio;
off_t fsize, len, cur, offset;
uint8_t *buf;
struct thread *td;
struct vnode *vp;
size_t iosize;
int error;
buf = NULL;
error = 0;
td = curthread;
vap = &vattr;
vp = ap->a_vp;
len = *ap->a_len;
offset = *ap->a_offset;
error = VOP_GETATTR(vp, vap, td->td_ucred);
if (error != 0)
goto out;
fsize = vap->va_size;
iosize = vap->va_blocksize;
if (iosize == 0)
iosize = BLKDEV_IOSIZE;
if (iosize > MAXPHYS)
iosize = MAXPHYS;
buf = malloc(iosize, M_TEMP, M_WAITOK);
#ifdef __notyet__
/*
* Check if the filesystem sets f_maxfilesize; if not use
* VOP_SETATTR to perform the check.
*/
sfs = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
error = VFS_STATFS(vp->v_mount, sfs, td);
if (error == 0)
maxfilesize = sfs->f_maxfilesize;
free(sfs, M_STATFS);
if (error != 0)
goto out;
if (maxfilesize) {
if (offset > maxfilesize || len > maxfilesize ||
offset + len > maxfilesize) {
error = EFBIG;
goto out;
}
} else
#endif
if (offset + len > vap->va_size) {
/*
* Test offset + len against the filesystem's maxfilesize.
*/
VATTR_NULL(vap);
vap->va_size = offset + len;
error = VOP_SETATTR(vp, vap, td->td_ucred);
if (error != 0)
goto out;
VATTR_NULL(vap);
vap->va_size = fsize;
error = VOP_SETATTR(vp, vap, td->td_ucred);
if (error != 0)
goto out;
}
for (;;) {
/*
* Read and write back anything below the nominal file
* size. There's currently no way outside the filesystem
* to know whether this area is sparse or not.
*/
cur = iosize;
if ((offset % iosize) != 0)
cur -= (offset % iosize);
if (cur > len)
cur = len;
if (offset < fsize) {
aiov.iov_base = buf;
aiov.iov_len = cur;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = offset;
auio.uio_resid = cur;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_READ;
auio.uio_td = td;
error = VOP_READ(vp, &auio, 0, td->td_ucred);
if (error != 0)
break;
if (auio.uio_resid > 0) {
bzero(buf + cur - auio.uio_resid,
auio.uio_resid);
}
} else {
bzero(buf, cur);
}
aiov.iov_base = buf;
aiov.iov_len = cur;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = offset;
auio.uio_resid = cur;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_WRITE;
auio.uio_td = td;
error = VOP_WRITE(vp, &auio, 0, td->td_ucred);
if (error != 0)
break;
len -= cur;
offset += cur;
if (len == 0)
break;
if (should_yield())
break;
}
out:
*ap->a_len = len;
*ap->a_offset = offset;
free(buf, M_TEMP);
return (error);
}
int
vop_stdadvise(struct vop_advise_args *ap)
{
struct vnode *vp;
struct bufobj *bo;
daddr_t startn, endn;
off_t bstart, bend, start, end;
int bsize, error;
vp = ap->a_vp;
switch (ap->a_advice) {
case POSIX_FADV_WILLNEED:
/*
* Do nothing for now. Filesystems should provide a
* custom method which starts an asynchronous read of
* the requested region.
*/
error = 0;
break;
case POSIX_FADV_DONTNEED:
error = 0;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (vp->v_iflag & VI_DOOMED) {
VOP_UNLOCK(vp, 0);
break;
}
/*
* Round to block boundaries (and later possibly further to
* page boundaries). Applications cannot reasonably be aware
* of the boundaries, and the rounding must be to expand at
* both extremities to cover enough. It still doesn't cover
* read-ahead. For partial blocks, this gives unnecessary
* discarding of buffers but is efficient enough since the
* pages usually remain in VMIO for some time.
*/
bsize = vp->v_bufobj.bo_bsize;
bstart = rounddown(ap->a_start, bsize);
bend = roundup(ap->a_end, bsize);
/*
* Deactivate pages in the specified range from the backing VM
* object. Pages that are resident in the buffer cache will
* remain wired until their corresponding buffers are released
* below.
*/
if (vp->v_object != NULL) {
start = trunc_page(bstart);
end = round_page(bend);
VM_OBJECT_RLOCK(vp->v_object);
vm_object_page_noreuse(vp->v_object, OFF_TO_IDX(start),
OFF_TO_IDX(end));
VM_OBJECT_RUNLOCK(vp->v_object);
}
bo = &vp->v_bufobj;
BO_RLOCK(bo);
startn = bstart / bsize;
endn = bend / bsize;
error = bnoreuselist(&bo->bo_clean, bo, startn, endn);
if (error == 0)
error = bnoreuselist(&bo->bo_dirty, bo, startn, endn);
BO_RUNLOCK(bo);
VOP_UNLOCK(vp, 0);
break;
default:
error = EINVAL;
break;
}
return (error);
}
int
vop_stdunp_bind(struct vop_unp_bind_args *ap)
{
ap->a_vp->v_unpcb = ap->a_unpcb;
return (0);
}
int
vop_stdunp_connect(struct vop_unp_connect_args *ap)
{
*ap->a_unpcb = ap->a_vp->v_unpcb;
return (0);
}
int
vop_stdunp_detach(struct vop_unp_detach_args *ap)
{
ap->a_vp->v_unpcb = NULL;
return (0);
}
static int
vop_stdis_text(struct vop_is_text_args *ap)
{
return (ap->a_vp->v_writecount < 0);
}
int
vop_stdset_text(struct vop_set_text_args *ap)
{
struct vnode *vp;
struct mount *mp;
int error;
vp = ap->a_vp;
VI_LOCK(vp);
if (vp->v_writecount > 0) {
error = ETXTBSY;
} else {
/*
* If requested by fs, keep a use reference to the
* vnode until the last text reference is released.
*/
mp = vp->v_mount;
if (mp != NULL && (mp->mnt_kern_flag & MNTK_TEXT_REFS) != 0 &&
vp->v_writecount == 0) {
vp->v_iflag |= VI_TEXT_REF;
vrefl(vp);
}
vp->v_writecount--;
error = 0;
}
VI_UNLOCK(vp);
return (error);
}
static int
vop_stdunset_text(struct vop_unset_text_args *ap)
{
struct vnode *vp;
int error;
bool last;
vp = ap->a_vp;
last = false;
VI_LOCK(vp);
if (vp->v_writecount < 0) {
if ((vp->v_iflag & VI_TEXT_REF) != 0 &&
vp->v_writecount == -1) {
last = true;
vp->v_iflag &= ~VI_TEXT_REF;
}
vp->v_writecount++;
error = 0;
} else {
error = EINVAL;
}
VI_UNLOCK(vp);
if (last)
vunref(vp);
return (error);
}
static int
vop_stdadd_writecount(struct vop_add_writecount_args *ap)
{
struct vnode *vp;
int error;
vp = ap->a_vp;
VI_LOCK_FLAGS(vp, MTX_DUPOK);
if (vp->v_writecount < 0) {
error = ETXTBSY;
} else {
VNASSERT(vp->v_writecount + ap->a_inc >= 0, vp,
("neg writecount increment %d", ap->a_inc));
vp->v_writecount += ap->a_inc;
error = 0;
}
VI_UNLOCK(vp);
return (error);
}
int
vop_stdneed_inactive(struct vop_need_inactive_args *ap)
{
return (1);
}
static int
vop_stdioctl(struct vop_ioctl_args *ap)
{
struct vnode *vp;
struct vattr va;
off_t *offp;
int error;
switch (ap->a_command) {
case FIOSEEKDATA:
case FIOSEEKHOLE:
vp = ap->a_vp;
error = vn_lock(vp, LK_SHARED);
if (error != 0)
return (EBADF);
if (vp->v_type == VREG)
error = VOP_GETATTR(vp, &va, ap->a_cred);
else
error = ENOTTY;
if (error == 0) {
offp = ap->a_data;
if (*offp < 0 || *offp >= va.va_size)
error = ENXIO;
else if (ap->a_command == FIOSEEKHOLE)
*offp = va.va_size;
}
VOP_UNLOCK(vp, 0);
break;
default:
error = ENOTTY;
break;
}
return (error);
}
/*
* vfs default ops
* used to fill the vfs function table to get reasonable default return values.
*/
int
vfs_stdroot (mp, flags, vpp)
struct mount *mp;
int flags;
struct vnode **vpp;
{
return (EOPNOTSUPP);
}
int
vfs_stdstatfs (mp, sbp)
struct mount *mp;
struct statfs *sbp;
{
return (EOPNOTSUPP);
}
int
vfs_stdquotactl (mp, cmds, uid, arg)
struct mount *mp;
int cmds;
uid_t uid;
void *arg;
{
return (EOPNOTSUPP);
}
int
vfs_stdsync(mp, waitfor)
struct mount *mp;
int waitfor;
{
struct vnode *vp, *mvp;
struct thread *td;
int error, lockreq, allerror = 0;
td = curthread;
lockreq = LK_EXCLUSIVE | LK_INTERLOCK;
if (waitfor != MNT_WAIT)
lockreq |= LK_NOWAIT;
/*
* Force stale buffer cache information to be flushed.
*/
loop:
MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
if (vp->v_bufobj.bo_dirty.bv_cnt == 0) {
VI_UNLOCK(vp);
continue;
}
if ((error = vget(vp, lockreq, td)) != 0) {
if (error == ENOENT) {
MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
goto loop;
}
continue;
}
error = VOP_FSYNC(vp, waitfor, td);
if (error)
allerror = error;
vput(vp);
}
return (allerror);
}
int
vfs_stdnosync (mp, waitfor)
struct mount *mp;
int waitfor;
{
return (0);
}
static int
vop_stdcopy_file_range(struct vop_copy_file_range_args *ap)
{
int error;
error = vn_generic_copy_file_range(ap->a_invp, ap->a_inoffp,
ap->a_outvp, ap->a_outoffp, ap->a_lenp, ap->a_flags, ap->a_incred,
ap->a_outcred, ap->a_fsizetd);
return (error);
}
int
vfs_stdvget (mp, ino, flags, vpp)
struct mount *mp;
ino_t ino;
int flags;
struct vnode **vpp;
{
return (EOPNOTSUPP);
}
int
vfs_stdfhtovp (mp, fhp, flags, vpp)
struct mount *mp;
struct fid *fhp;
int flags;
struct vnode **vpp;
{
return (EOPNOTSUPP);
}
int
vfs_stdinit (vfsp)
struct vfsconf *vfsp;
{
return (0);
}
int
vfs_stduninit (vfsp)
struct vfsconf *vfsp;
{
return(0);
}
int
vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace, attrname)
struct mount *mp;
int cmd;
struct vnode *filename_vp;
int attrnamespace;
const char *attrname;
{
if (filename_vp != NULL)
VOP_UNLOCK(filename_vp, 0);
return (EOPNOTSUPP);
}
int
vfs_stdsysctl(mp, op, req)
struct mount *mp;
fsctlop_t op;
struct sysctl_req *req;
{
return (EOPNOTSUPP);
}
static vop_bypass_t *
bp_by_off(struct vop_vector *vop, struct vop_generic_args *a)
{
return (*(vop_bypass_t **)((char *)vop + a->a_desc->vdesc_vop_offset));
}
int
vop_sigdefer(struct vop_vector *vop, struct vop_generic_args *a)
{
vop_bypass_t *bp;
int prev_stops, rc;
for (; vop != NULL; vop = vop->vop_default) {
bp = bp_by_off(vop, a);
if (bp != NULL)
break;
/*
* Bypass is not really supported. It is done for
* fallback to unimplemented vops in the default
* vector.
*/
bp = vop->vop_bypass;
if (bp != NULL)
break;
}
MPASS(bp != NULL);
prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT);
rc = bp(a);
sigallowstop(prev_stops);
return (rc);
}
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