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c40487d49b
freebsd-skq/sys/kern/vfs_default.c
Konstantin Belousov 3c484f325e Convert page cache read to VOP. 
There are several negative side-effects of not calling into VOP layer
at all for page cache reads.  The biggest is the missed activation of
EVFILT_READ knotes.

Also, it allows filesystem to make more fine grained decision to
refuse read from page cache.

Keep VIRF_PGREAD flag around, it is still useful for nullfs, and for
asserts.

Reviewed by:	markj
Tested by:	pho
Discussed with:	mjg
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D26346
2020-09-15 22:06:36 +00:00

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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 <sys/stat.h>
#include <security/audit/audit.h>
#include <sys/priv.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_stdread_pgcache(struct vop_read_pgcache_args *ap);
static int vop_stdstat(struct vop_stat_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_stat = vop_stdstat,
.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_read_pgcache = vop_stdread_pgcache,
.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,
};
VFS_VOP_VECTOR_REGISTER(default_vnodeops);
/*
* 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);
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);
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_flags(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;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
return (lockmgr_unlock(vp->v_vnlock));
}
/* See above. */
int
vop_stdislocked(ap)
struct vop_islocked_args /* {
struct vnode *a_vp;
} */ *ap;
{
return (lockstatus(ap->a_vp->v_vnlock));
}
/*
* Variants of the above set.
*
* Differences are:
* - shared locking disablement is not supported
* - v_vnlock pointer is not honored
*/
int
vop_lock(ap)
struct vop_lock1_args /* {
struct vnode *a_vp;
int a_flags;
char *file;
int line;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
int flags = ap->a_flags;
struct mtx *ilk;
MPASS(vp->v_vnlock == &vp->v_lock);
if (__predict_false((flags & ~(LK_TYPE_MASK | LK_NODDLKTREAT | LK_RETRY)) != 0))
goto other;
switch (flags & LK_TYPE_MASK) {
case LK_SHARED:
return (lockmgr_slock(&vp->v_lock, flags, ap->a_file, ap->a_line));
case LK_EXCLUSIVE:
return (lockmgr_xlock(&vp->v_lock, flags, ap->a_file, ap->a_line));
}
other:
ilk = VI_MTX(vp);
return (lockmgr_lock_flags(&vp->v_lock, flags,
&ilk->lock_object, ap->a_file, ap->a_line));
}
int
vop_unlock(ap)
struct vop_unlock_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
MPASS(vp->v_vnlock == &vp->v_lock);
return (lockmgr_unlock(&vp->v_lock));
}
int
vop_islocked(ap)
struct vop_islocked_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
MPASS(vp->v_vnlock == &vp->v_lock);
return (lockstatus(&vp->v_lock));
}
/*
* 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;
{
if (ap->a_events & ~POLLSTANDARD)
return (POLLNVAL);
return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
}
/*
* 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 VIRF_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);
if (ap->a_iodone != NULL)
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;
size_t *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);
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);
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);
vn_lock(mvp, LK_SHARED | LK_RETRY);
if (dirent_exists(mvp, dp->d_name, td)) {
error = ENOENT;
VOP_UNLOCK(mvp);
vn_lock(*dvp, LK_SHARED | LK_RETRY);
goto out;
}
VOP_UNLOCK(mvp);
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);
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 (VN_IS_DOOMED(vp)) {
VOP_UNLOCK(vp);
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);
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) {
VNPASS((vp->v_iflag & VI_TEXT_REF) == 0, vp);
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;
struct mount *mp;
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));
if (vp->v_writecount == 0) {
mp = vp->v_mount;
if (mp != NULL && (mp->mnt_kern_flag & MNTK_NOMSYNC) == 0)
vlazy(vp);
}
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);
}
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);
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)) != 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);
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;
bp = bp_by_off(vop, a);
MPASS(bp != NULL);
prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT);
rc = bp(a);
sigallowstop(prev_stops);
return (rc);
}
static int
vop_stdstat(struct vop_stat_args *a)
{
struct vattr vattr;
struct vattr *vap;
struct vnode *vp;
struct stat *sb;
int error;
u_short mode;
vp = a->a_vp;
sb = a->a_sb;
error = vop_stat_helper_pre(a);
if (error != 0)
return (error);
vap = &vattr;
/*
* Initialize defaults for new and unusual fields, so that file
* systems which don't support these fields don't need to know
* about them.
*/
vap->va_birthtime.tv_sec = -1;
vap->va_birthtime.tv_nsec = 0;
vap->va_fsid = VNOVAL;
vap->va_rdev = NODEV;
error = VOP_GETATTR(vp, vap, a->a_active_cred);
if (error)
goto out;
/*
* 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;
break;
case VSOCK:
mode |= S_IFSOCK;
break;
case VFIFO:
mode |= S_IFIFO;
break;
default:
error = EBADF;
goto out;
}
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) {
error = EOVERFLOW;
goto out;
}
sb->st_size = vap->va_size;
sb->st_atim.tv_sec = vap->va_atime.tv_sec;
sb->st_atim.tv_nsec = vap->va_atime.tv_nsec;
sb->st_mtim.tv_sec = vap->va_mtime.tv_sec;
sb->st_mtim.tv_nsec = vap->va_mtime.tv_nsec;
sb->st_ctim.tv_sec = vap->va_ctime.tv_sec;
sb->st_ctim.tv_nsec = vap->va_ctime.tv_nsec;
sb->st_birthtim.tv_sec = vap->va_birthtime.tv_sec;
sb->st_birthtim.tv_nsec = vap->va_birthtime.tv_nsec;
/*
* 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"
* Use minimum/default of PAGE_SIZE (e.g. for VCHR).
*/
sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
sb->st_flags = vap->va_flags;
sb->st_blocks = vap->va_bytes / S_BLKSIZE;
sb->st_gen = vap->va_gen;
out:
return (vop_stat_helper_post(a, error));
}
static int
vop_stdread_pgcache(struct vop_read_pgcache_args *ap __unused)
{
return (EJUSTRETURN);
}
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