freebsd-nq/sys/kern/vfs_default.c
Peter Wemm b21126c6b3 Clean up the stub fake vnode locking implemenations. The main reason this
stuff was here (NFS) was fixed by Alfred in November.  The only remaining
consumer of the stub functions was umapfs, which is horribly horribly
broken.  It has missed out on about the last 5 years worth of maintenence
that was done on nullfs (from which umapfs is derived).  It needs major
work to bring it up to date with the vnode locking protocol.  umapfs really
needs to find a caretaker to bring it into the 21st century.

Functions GC'ed:
vop_noislocked, vop_nolock, vop_nounlock, vop_sharedlock.
2004-03-29 22:41:21 +00:00

817 lines
18 KiB
C

/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <sys/poll.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_nostrategy(struct vop_strategy_args *);
/*
* 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.
*
*/
vop_t **default_vnodeop_p;
static struct vnodeopv_entry_desc default_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_eopnotsupp },
{ &vop_advlock_desc, (vop_t *) vop_einval },
{ &vop_bmap_desc, (vop_t *) vop_stdbmap },
{ &vop_close_desc, (vop_t *) vop_null },
{ &vop_createvobject_desc, (vop_t *) vop_stdcreatevobject },
{ &vop_destroyvobject_desc, (vop_t *) vop_stddestroyvobject },
{ &vop_fsync_desc, (vop_t *) vop_null },
{ &vop_getpages_desc, (vop_t *) vop_stdgetpages },
{ &vop_getvobject_desc, (vop_t *) vop_stdgetvobject },
{ &vop_inactive_desc, (vop_t *) vop_stdinactive },
{ &vop_ioctl_desc, (vop_t *) vop_enotty },
{ &vop_islocked_desc, (vop_t *) vop_stdislocked },
{ &vop_lease_desc, (vop_t *) vop_null },
{ &vop_lock_desc, (vop_t *) vop_stdlock },
{ &vop_lookup_desc, (vop_t *) vop_nolookup },
{ &vop_open_desc, (vop_t *) vop_null },
{ &vop_pathconf_desc, (vop_t *) vop_einval },
{ &vop_poll_desc, (vop_t *) vop_nopoll },
{ &vop_putpages_desc, (vop_t *) vop_stdputpages },
{ &vop_readlink_desc, (vop_t *) vop_einval },
{ &vop_revoke_desc, (vop_t *) vop_revoke },
{ &vop_specstrategy_desc, (vop_t *) vop_panic },
{ &vop_strategy_desc, (vop_t *) vop_nostrategy },
{ &vop_unlock_desc, (vop_t *) vop_stdunlock },
{ NULL, NULL }
};
static struct vnodeopv_desc default_vnodeop_opv_desc =
{ &default_vnodeop_p, default_vnodeop_entries };
VNODEOP_SET(default_vnodeop_opv_desc);
/*
* 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_null(struct vop_generic_args *ap)
{
return (0);
}
/*
* Used to make a defined VOP fall back to the default VOP.
*/
int
vop_defaultop(struct vop_generic_args *ap)
{
return (VOCALL(default_vnodeop_p, ap->a_desc->vdesc_offset, ap));
}
/*
* 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_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)
{
KASSERT(ap->a_vp == ap->a_bp->b_vp, ("%s(%p != %p)",
__func__, ap->a_vp, ap->a_bp->b_vp));
printf("No strategy for buffer at %p\n", ap->a_bp);
vprint("vnode", ap->a_vp);
vprint("device vnode", ap->a_bp->b_vp);
ap->a_bp->b_ioflags |= BIO_ERROR;
ap->a_bp->b_error = EOPNOTSUPP;
bufdone(ap->a_bp);
return (EOPNOTSUPP);
}
/*
* 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_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_lock_args /* {
struct vnode *a_vp;
int a_flags;
struct thread *a_td;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
#ifndef DEBUG_LOCKS
return (lockmgr(vp->v_vnlock, ap->a_flags, VI_MTX(vp), ap->a_td));
#else
return (debuglockmgr(vp->v_vnlock, ap->a_flags, VI_MTX(vp),
ap->a_td, "vop_stdlock", vp->filename, vp->line));
#endif
}
/* See above. */
int
vop_stdunlock(ap)
struct vop_unlock_args /* {
struct vnode *a_vp;
int a_flags;
struct thread *a_td;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
return (lockmgr(vp->v_vnlock, ap->a_flags | LK_RELEASE, VI_MTX(vp),
ap->a_td));
}
/* See above. */
int
vop_stdislocked(ap)
struct vop_islocked_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
return (lockstatus(ap->a_vp->v_vnlock, ap->a_td));
}
/* Mark the vnode inactive */
int
vop_stdinactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
VOP_UNLOCK(ap->a_vp, 0, ap->a_td);
return (0);
}
/*
* 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 true for read/write. If the user asked for something
* special, return POLLNVAL, so that clients have a way of
* determining reliably whether or not the extended
* functionality is present without hard-coding knowledge
* of specific filesystem implementations.
* Stay in sync with kern_conf.c::no_poll().
*/
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;
{
*(ap->a_mpp) = ap->a_vp->v_mount;
return (0);
}
/* Create the VM system backing object for this vnode */
int
vop_stdcreatevobject(ap)
struct vop_createvobject_args /* {
struct vnode *vp;
struct ucred *cred;
struct thread *td;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct ucred *cred = ap->a_cred;
struct thread *td = ap->a_td;
struct vattr vat;
vm_object_t object;
int error = 0;
GIANT_REQUIRED;
if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
return (0);
retry:
if ((object = vp->v_object) == NULL) {
if (vp->v_type == VREG || vp->v_type == VDIR) {
if ((error = VOP_GETATTR(vp, &vat, cred, td)) != 0)
goto retn;
object = vnode_pager_alloc(vp, vat.va_size, 0, 0);
} else if (devsw(vp->v_rdev) != NULL) {
/*
* This simply allocates the biggest object possible
* for a disk vnode. This should be fixed, but doesn't
* cause any problems (yet).
*/
object = vnode_pager_alloc(vp, IDX_TO_OFF(INT_MAX), 0, 0);
} else {
goto retn;
}
/*
* Dereference the reference we just created. This assumes
* that the object is associated with the vp.
*/
VM_OBJECT_LOCK(object);
object->ref_count--;
VM_OBJECT_UNLOCK(object);
vrele(vp);
} else {
VM_OBJECT_LOCK(object);
if (object->flags & OBJ_DEAD) {
VOP_UNLOCK(vp, 0, td);
msleep(object, VM_OBJECT_MTX(object), PDROP | PVM,
"vodead", 0);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
goto retry;
}
VM_OBJECT_UNLOCK(object);
}
KASSERT(vp->v_object != NULL, ("vfs_object_create: NULL object"));
vp->v_vflag |= VV_OBJBUF;
retn:
return (error);
}
/* Destroy the VM system object associated with this vnode */
int
vop_stddestroyvobject(ap)
struct vop_destroyvobject_args /* {
struct vnode *vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
vm_object_t obj = vp->v_object;
GIANT_REQUIRED;
if (obj == NULL)
return (0);
VM_OBJECT_LOCK(obj);
if (obj->ref_count == 0) {
/*
* vclean() may be called twice. The first time
* removes the primary reference to the object,
* the second time goes one further and is a
* special-case to terminate the object.
*
* don't double-terminate the object
*/
if ((obj->flags & OBJ_DEAD) == 0)
vm_object_terminate(obj);
else
VM_OBJECT_UNLOCK(obj);
} else {
/*
* Woe to the process that tries to page now :-).
*/
vm_pager_deallocate(obj);
VM_OBJECT_UNLOCK(obj);
}
return (0);
}
/*
* Return the underlying VM object. This routine may be called with or
* without the vnode interlock held. If called without, the returned
* object is not guarenteed to be valid. The syncer typically gets the
* object without holding the interlock in order to quickly test whether
* it might be dirty before going heavy-weight. vm_object's use zalloc
* and thus stable-storage, so this is safe.
*/
int
vop_stdgetvobject(ap)
struct vop_getvobject_args /* {
struct vnode *vp;
struct vm_object **objpp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct vm_object **objpp = ap->a_objpp;
if (objpp)
*objpp = vp->v_object;
return (vp->v_object ? 0 : EINVAL);
}
/* 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 vnode **a_vpp;
daddr_t *a_bnp;
int *a_runp;
int *a_runb;
} */ *ap;
{
if (ap->a_vpp != NULL)
*ap->a_vpp = ap->a_vp;
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 buf *nbp;
int s, error = 0;
int maxretry = 100; /* large, arbitrarily chosen */
VI_LOCK(vp);
loop1:
/*
* MARK/SCAN initialization to avoid infinite loops.
*/
s = splbio();
TAILQ_FOREACH(bp, &vp->v_dirtyblkhd, b_vnbufs) {
bp->b_vflags &= ~BV_SCANNED;
bp->b_error = 0;
}
splx(s);
/*
* Flush all dirty buffers associated with a block device.
*/
loop2:
s = splbio();
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp != NULL; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if ((bp->b_vflags & BV_SCANNED) != 0)
continue;
bp->b_vflags |= BV_SCANNED;
if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL))
continue;
VI_UNLOCK(vp);
if ((bp->b_flags & B_DELWRI) == 0)
panic("fsync: not dirty");
if ((vp->v_vflag & VV_OBJBUF) && (bp->b_flags & B_CLUSTEROK)) {
vfs_bio_awrite(bp);
splx(s);
} else {
bremfree(bp);
splx(s);
bawrite(bp);
}
VI_LOCK(vp);
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) {
while (vp->v_numoutput) {
vp->v_iflag |= VI_BWAIT;
msleep((caddr_t)&vp->v_numoutput, VI_MTX(vp),
PRIBIO + 1, "fsync", 0);
}
if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
/*
* 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, &vp->v_dirtyblkhd, b_vnbufs)
if ((error = bp->b_error) == 0)
continue;
if (error == 0 && --maxretry >= 0) {
splx(s);
goto loop1;
}
vprint("fsync: giving up on dirty", vp);
error = EAGAIN;
}
}
VI_UNLOCK(vp);
splx(s);
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_reqpage;
vm_ooffset_t a_offset;
} */ *ap;
{
return vnode_pager_generic_getpages(ap->a_vp, ap->a_m,
ap->a_count, ap->a_reqpage);
}
/* 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;
vm_ooffset_t a_offset;
} */ *ap;
{
return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
ap->a_sync, ap->a_rtvals);
}
/*
* vfs default ops
* used to fill the vfs function table to get reasonable default return values.
*/
int
vfs_stdroot (mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
return (EOPNOTSUPP);
}
int
vfs_stdstatfs (mp, sbp, td)
struct mount *mp;
struct statfs *sbp;
struct thread *td;
{
return (EOPNOTSUPP);
}
int
vfs_stdvptofh (vp, fhp)
struct vnode *vp;
struct fid *fhp;
{
return (EOPNOTSUPP);
}
int
vfs_stdstart (mp, flags, td)
struct mount *mp;
int flags;
struct thread *td;
{
return (0);
}
int
vfs_stdquotactl (mp, cmds, uid, arg, td)
struct mount *mp;
int cmds;
uid_t uid;
caddr_t arg;
struct thread *td;
{
return (EOPNOTSUPP);
}
int
vfs_stdsync(mp, waitfor, cred, td)
struct mount *mp;
int waitfor;
struct ucred *cred;
struct thread *td;
{
struct vnode *vp, *nvp;
int error, lockreq, allerror = 0;
lockreq = LK_EXCLUSIVE | LK_INTERLOCK;
if (waitfor != MNT_WAIT)
lockreq |= LK_NOWAIT;
/*
* Force stale buffer cache information to be flushed.
*/
MNT_ILOCK(mp);
loop:
for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
/*
* If the vnode that we are about to sync is no longer
* associated with this mount point, start over.
*/
if (vp->v_mount != mp)
goto loop;
nvp = TAILQ_NEXT(vp, v_nmntvnodes);
VI_LOCK(vp);
if (TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
VI_UNLOCK(vp);
continue;
}
MNT_IUNLOCK(mp);
if ((error = vget(vp, lockreq, td)) != 0) {
MNT_ILOCK(mp);
if (error == ENOENT)
goto loop;
continue;
}
error = VOP_FSYNC(vp, cred, waitfor, td);
if (error)
allerror = error;
VOP_UNLOCK(vp, 0, td);
vrele(vp);
MNT_ILOCK(mp);
}
MNT_IUNLOCK(mp);
return (allerror);
}
int
vfs_stdnosync (mp, waitfor, cred, td)
struct mount *mp;
int waitfor;
struct ucred *cred;
struct thread *td;
{
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, vpp)
struct mount *mp;
struct fid *fhp;
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, td)
struct mount *mp;
int cmd;
struct vnode *filename_vp;
int attrnamespace;
const char *attrname;
struct thread *td;
{
if (filename_vp != NULL)
VOP_UNLOCK(filename_vp, 0, td);
return(EOPNOTSUPP);
}
/* end of vfs default ops */