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2832ade6b8
freebsd-nq/sys/kern/vfs_default.c
Gleb Smirnoff b0cd20172d A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). 
o With new KPI consumers can request contiguous ranges of pages, and
  unlike before, all pages will be kept busied on return, like it was
  done before with the 'reqpage' only. Now the reqpage goes away. With
  new interface it is easier to implement code protected from race
  conditions.

  Such arrayed requests for now should be preceeded by a call to
  vm_pager_haspage() to make sure that request is possible. This
  could be improved later, making vm_pager_haspage() obsolete.

  Strenghtening the promises on the business of the array of pages
  allows us to remove such hacks as swp_pager_free_nrpage() and
  vm_pager_free_nonreq().

o New KPI accepts two integer pointers that may optionally point at
  values for read ahead and read behind, that a pager may do, if it
  can. These pages are completely owned by pager, and not controlled
  by the caller.

  This shifts the UFS-specific readahead logic from vm_fault.c, which
  should be file system agnostic, into vnode_pager.c. It also removes
  one VOP_BMAP() request per hard fault.

Discussed with:	kib, alc, jeff, scottl
Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2015-12-16 21:30:45 +00:00

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/*-
* 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.
* 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.
*/
#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/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_stdset_text(struct vop_set_text_args *ap);
static int vop_stdunset_text(struct vop_unset_text_args *ap);
static int vop_stdget_writecount(struct vop_get_writecount_args *ap);
static int vop_stdadd_writecount(struct vop_add_writecount_args *ap);
static int vop_stdgetpages_async(struct vop_getpages_async_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_getpages = vop_stdgetpages,
.vop_getpages_async = vop_stdgetpages_async,
.vop_getwritemount = vop_stdgetwritemount,
.vop_inactive = VOP_NULL,
.vop_ioctl = VOP_ENOTTY,
.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_get_writecount = vop_stdget_writecount,
.vop_add_writecount = vop_stdadd_writecount,
};
/*
* 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);
vprint("vnode", ap->a_vp);
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_NAME_MAX:
*ap->a_retval = NAME_MAX;
return (0);
case _PC_PATH_MAX:
*ap->a_retval = PATH_MAX;
return (0);
case _PC_LINK_MAX:
*ap->a_retval = LINK_MAX;
return (0);
case _PC_MAX_CANON:
*ap->a_retval = MAX_CANON;
return (0);
case _PC_MAX_INPUT:
*ap->a_retval = MAX_INPUT;
return (0);
case _PC_PIPE_BUF:
*ap->a_retval = PIPE_BUF;
return (0);
case _PC_CHOWN_RESTRICTED:
*ap->a_retval = 1;
return (0);
case _PC_VDISABLE:
*ap->a_retval = _POSIX_VDISABLE;
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;
return (_lockmgr_args(vp->v_vnlock, ap->a_flags, VI_MTX(vp),
LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, 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;
return (lockmgr(vp->v_vnlock, ap->a_flags | LK_RELEASE, VI_MTX(vp)));
}
/* 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;
/*
* XXX Since this is called unlocked we may be recycled while
* attempting to ref the mount. If this is the case or mountpoint
* will be set to NULL. We only have to prevent this call from
* returning with a ref to an incorrect mountpoint. It is not
* harmful to return with a ref to our previous mountpoint.
*/
mp = ap->a_vp->v_mount;
if (mp != NULL) {
vfs_ref(mp);
if (mp != ap->a_vp->v_mount) {
vfs_rel(mp);
mp = NULL;
}
}
*(ap->a_mpp) = mp;
return (0);
}
/* XXX Needs good comment and VOP_BMAP(9) manpage */
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;
struct ucred *a_cred;
int a_waitfor;
struct thread *a_td;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct buf *bp;
struct bufobj *bo;
struct buf *nbp;
int error = 0;
int maxretry = 1000; /* large, arbitrarily chosen */
bo = &vp->v_bufobj;
BO_LOCK(bo);
loop1:
/*
* MARK/SCAN initialization to avoid infinite loops.
*/
TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
bp->b_vflags &= ~BV_SCANNED;
bp->b_error = 0;
}
/*
* Flush all dirty buffers associated with a vnode.
*/
loop2:
TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
if ((bp->b_vflags & BV_SCANNED) != 0)
continue;
bp->b_vflags |= BV_SCANNED;
if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
if (ap->a_waitfor != MNT_WAIT)
continue;
if (BUF_LOCK(bp,
LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
BO_LOCKPTR(bo)) != 0) {
BO_LOCK(bo);
goto loop1;
}
BO_LOCK(bo);
}
BO_UNLOCK(bo);
KASSERT(bp->b_bufobj == bo,
("bp %p wrong b_bufobj %p should be %p",
bp, bp->b_bufobj, bo));
if ((bp->b_flags & B_DELWRI) == 0)
panic("fsync: not dirty");
if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
vfs_bio_awrite(bp);
} else {
bremfree(bp);
bawrite(bp);
}
BO_LOCK(bo);
goto loop2;
}
/*
* If synchronous the caller expects us to completely resolve all
* dirty buffers in the system. Wait for in-progress I/O to
* complete (which could include background bitmap writes), then
* retry if dirty blocks still exist.
*/
if (ap->a_waitfor == MNT_WAIT) {
bufobj_wwait(bo, 0, 0);
if (bo->bo_dirty.bv_cnt > 0) {
/*
* If we are unable to write any of these buffers
* then we fail now rather than trying endlessly
* to write them out.
*/
TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
if ((error = bp->b_error) == 0)
continue;
if (error == 0 && --maxretry >= 0)
goto loop1;
error = EAGAIN;
}
}
BO_UNLOCK(bo);
if (error == EAGAIN)
vprint("fsync: giving up on dirty", vp);
return (error);
}
/* 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;
#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.
*/
error = VFS_STATFS(vp->v_mount, &sfs, td);
if (error != 0)
goto out;
if (sfs.f_maxfilesize) {
if (offset > sfs.f_maxfilesize || len > sfs.f_maxfilesize ||
offset + len > sfs.f_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 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;
}
/*
* 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(ap->a_start);
end = round_page(ap->a_end);
VM_OBJECT_WLOCK(vp->v_object);
vm_object_page_noreuse(vp->v_object, OFF_TO_IDX(start),
OFF_TO_IDX(end));
VM_OBJECT_WUNLOCK(vp->v_object);
}
bo = &vp->v_bufobj;
BO_RLOCK(bo);
bsize = vp->v_bufobj.bo_bsize;
startn = ap->a_start / bsize;
endn = ap->a_end / bsize;
for (;;) {
error = bnoreuselist(&bo->bo_clean, bo, startn, endn);
if (error == EAGAIN)
continue;
error = bnoreuselist(&bo->bo_dirty, bo, startn, endn);
if (error == EAGAIN)
continue;
break;
}
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_socket = ap->a_socket;
return (0);
}
int
vop_stdunp_connect(struct vop_unp_connect_args *ap)
{
*ap->a_socket = ap->a_vp->v_socket;
return (0);
}
int
vop_stdunp_detach(struct vop_unp_detach_args *ap)
{
ap->a_vp->v_socket = NULL;
return (0);
}
static int
vop_stdis_text(struct vop_is_text_args *ap)
{
return ((ap->a_vp->v_vflag & VV_TEXT) != 0);
}
static int
vop_stdset_text(struct vop_set_text_args *ap)
{
ap->a_vp->v_vflag |= VV_TEXT;
return (0);
}
static int
vop_stdunset_text(struct vop_unset_text_args *ap)
{
ap->a_vp->v_vflag &= ~VV_TEXT;
return (0);
}
static int
vop_stdget_writecount(struct vop_get_writecount_args *ap)
{
*ap->a_writecount = ap->a_vp->v_writecount;
return (0);
}
static int
vop_stdadd_writecount(struct vop_add_writecount_args *ap)
{
ap->a_vp->v_writecount += ap->a_inc;
return (0);
}
/*
* 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);
}
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);
}
/* end of vfs default ops */
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