NetBSD/sys/miscfs/genfs/genfs_vnops.c
elad 8fc0d7a9c3 Introduce per-page fingerprints in Veriexec.
This closes a hole pointed out by Thor Lancelot Simon on tech-kern ~3
years ago.

The problem was with running binaries from remote storage, where our
kernel (and Veriexec) has no control over any changes to files.

An attacker could, after the fingerprint has been verified and
program loaded to memory, inject malicious code into the backing
store on the remote storage, followed by a forced flush, causing
a page-in of the malicious data from backing store, bypassing
integrity checks.

Initial implementation by Brett Lymn.
2005-10-05 13:48:48 +00:00

1934 lines
46 KiB
C

/* $NetBSD: genfs_vnops.c,v 1.105 2005/10/05 13:48:48 elad Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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>
__KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.105 2005/10/05 13:48:48 elad Exp $");
#if defined(_KERNEL_OPT)
#include "opt_nfsserver.h"
#include "opt_verified_exec.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/poll.h>
#include <sys/mman.h>
#include <sys/file.h>
#ifdef VERIFIED_EXEC
#include <sys/verified_exec.h>
#endif /* VERIFIED_EXEC */
#include <miscfs/genfs/genfs.h>
#include <miscfs/genfs/genfs_node.h>
#include <miscfs/specfs/specdev.h>
#include <uvm/uvm.h>
#include <uvm/uvm_pager.h>
#ifdef NFSSERVER
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nqnfs.h>
#include <nfs/nfs_var.h>
#endif
static __inline void genfs_rel_pages(struct vm_page **, int);
static void filt_genfsdetach(struct knote *);
static int filt_genfsread(struct knote *, long);
static int filt_genfsvnode(struct knote *, long);
#define MAX_READ_AHEAD 16 /* XXXUBC 16 */
int genfs_rapages = MAX_READ_AHEAD; /* # of pages in each chunk of readahead */
int genfs_racount = 2; /* # of page chunks to readahead */
int genfs_raskip = 2; /* # of busy page chunks allowed to skip */
int
genfs_poll(void *v)
{
struct vop_poll_args /* {
struct vnode *a_vp;
int a_events;
struct proc *a_p;
} */ *ap = v;
return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
}
int
genfs_fsync(void *v)
{
struct vop_fsync_args /* {
struct vnode *a_vp;
struct ucred *a_cred;
int a_flags;
off_t offlo;
off_t offhi;
struct proc *a_p;
} */ *ap = v;
struct vnode *vp = ap->a_vp, *dvp;
int wait;
int error;
wait = (ap->a_flags & FSYNC_WAIT) != 0;
vflushbuf(vp, wait);
if ((ap->a_flags & FSYNC_DATAONLY) != 0)
error = 0;
else
error = VOP_UPDATE(vp, NULL, NULL, wait ? UPDATE_WAIT : 0);
if (error == 0 && ap->a_flags & FSYNC_CACHE) {
int l = 0;
if (VOP_BMAP(vp, 0, &dvp, NULL, NULL))
error = ENXIO;
else
error = VOP_IOCTL(dvp, DIOCCACHESYNC, &l, FWRITE,
ap->a_p->p_ucred, ap->a_p);
}
return (error);
}
int
genfs_seek(void *v)
{
struct vop_seek_args /* {
struct vnode *a_vp;
off_t a_oldoff;
off_t a_newoff;
struct ucred *a_ucred;
} */ *ap = v;
if (ap->a_newoff < 0)
return (EINVAL);
return (0);
}
int
genfs_abortop(void *v)
{
struct vop_abortop_args /* {
struct vnode *a_dvp;
struct componentname *a_cnp;
} */ *ap = v;
if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
PNBUF_PUT(ap->a_cnp->cn_pnbuf);
return (0);
}
int
genfs_fcntl(void *v)
{
struct vop_fcntl_args /* {
struct vnode *a_vp;
u_int a_command;
caddr_t a_data;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap = v;
if (ap->a_command == F_SETFL)
return (0);
else
return (EOPNOTSUPP);
}
/*ARGSUSED*/
int
genfs_badop(void *v)
{
panic("genfs: bad op");
}
/*ARGSUSED*/
int
genfs_nullop(void *v)
{
return (0);
}
/*ARGSUSED*/
int
genfs_einval(void *v)
{
return (EINVAL);
}
/*
* Called when an fs doesn't support a particular vop.
* This takes care to vrele, vput, or vunlock passed in vnodes.
*/
int
genfs_eopnotsupp(void *v)
{
struct vop_generic_args /*
struct vnodeop_desc *a_desc;
/ * other random data follows, presumably * /
} */ *ap = v;
struct vnodeop_desc *desc = ap->a_desc;
struct vnode *vp, *vp_last = NULL;
int flags, i, j, offset;
flags = desc->vdesc_flags;
for (i = 0; i < VDESC_MAX_VPS; flags >>=1, i++) {
if ((offset = desc->vdesc_vp_offsets[i]) == VDESC_NO_OFFSET)
break; /* stop at end of list */
if ((j = flags & VDESC_VP0_WILLPUT)) {
vp = *VOPARG_OFFSETTO(struct vnode **, offset, ap);
/* Skip if NULL */
if (!vp)
continue;
switch (j) {
case VDESC_VP0_WILLPUT:
/* Check for dvp == vp cases */
if (vp == vp_last)
vrele(vp);
else {
vput(vp);
vp_last = vp;
}
break;
case VDESC_VP0_WILLUNLOCK:
VOP_UNLOCK(vp, 0);
break;
case VDESC_VP0_WILLRELE:
vrele(vp);
break;
}
}
}
return (EOPNOTSUPP);
}
/*ARGSUSED*/
int
genfs_ebadf(void *v)
{
return (EBADF);
}
/* ARGSUSED */
int
genfs_enoioctl(void *v)
{
return (EPASSTHROUGH);
}
/*
* Eliminate all activity associated with the requested vnode
* and with all vnodes aliased to the requested vnode.
*/
int
genfs_revoke(void *v)
{
struct vop_revoke_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap = v;
struct vnode *vp, *vq;
struct proc *p = curproc; /* XXX */
#ifdef DIAGNOSTIC
if ((ap->a_flags & REVOKEALL) == 0)
panic("genfs_revoke: not revokeall");
#endif
vp = ap->a_vp;
simple_lock(&vp->v_interlock);
if (vp->v_flag & VALIASED) {
/*
* If a vgone (or vclean) is already in progress,
* wait until it is done and return.
*/
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
ltsleep(vp, PINOD|PNORELOCK, "vop_revokeall", 0,
&vp->v_interlock);
return (0);
}
/*
* Ensure that vp will not be vgone'd while we
* are eliminating its aliases.
*/
vp->v_flag |= VXLOCK;
simple_unlock(&vp->v_interlock);
while (vp->v_flag & VALIASED) {
simple_lock(&spechash_slock);
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_rdev != vp->v_rdev ||
vq->v_type != vp->v_type || vp == vq)
continue;
simple_unlock(&spechash_slock);
vgone(vq);
break;
}
if (vq == NULLVP)
simple_unlock(&spechash_slock);
}
/*
* Remove the lock so that vgone below will
* really eliminate the vnode after which time
* vgone will awaken any sleepers.
*/
simple_lock(&vp->v_interlock);
vp->v_flag &= ~VXLOCK;
}
vgonel(vp, p);
return (0);
}
/*
* Lock the node.
*/
int
genfs_lock(void *v)
{
struct vop_lock_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
return (lockmgr(vp->v_vnlock, ap->a_flags, &vp->v_interlock));
}
/*
* Unlock the node.
*/
int
genfs_unlock(void *v)
{
struct vop_unlock_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
return (lockmgr(vp->v_vnlock, ap->a_flags | LK_RELEASE,
&vp->v_interlock));
}
/*
* Return whether or not the node is locked.
*/
int
genfs_islocked(void *v)
{
struct vop_islocked_args /* {
struct vnode *a_vp;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
return (lockstatus(vp->v_vnlock));
}
/*
* Stubs to use when there is no locking to be done on the underlying object.
*/
int
genfs_nolock(void *v)
{
struct vop_lock_args /* {
struct vnode *a_vp;
int a_flags;
struct proc *a_p;
} */ *ap = v;
/*
* Since we are not using the lock manager, we must clear
* the interlock here.
*/
if (ap->a_flags & LK_INTERLOCK)
simple_unlock(&ap->a_vp->v_interlock);
return (0);
}
int
genfs_nounlock(void *v)
{
return (0);
}
int
genfs_noislocked(void *v)
{
return (0);
}
/*
* Local lease check for NFS servers. Just set up args and let
* nqsrv_getlease() do the rest. If NFSSERVER is not in the kernel,
* this is a null operation.
*/
int
genfs_lease_check(void *v)
{
#ifdef NFSSERVER
struct vop_lease_args /* {
struct vnode *a_vp;
struct proc *a_p;
struct ucred *a_cred;
int a_flag;
} */ *ap = v;
u_int32_t duration = 0;
int cache;
u_quad_t frev;
(void) nqsrv_getlease(ap->a_vp, &duration, ND_CHECK | ap->a_flag,
NQLOCALSLP, ap->a_p, (struct mbuf *)0, &cache, &frev, ap->a_cred);
return (0);
#else
return (0);
#endif /* NFSSERVER */
}
int
genfs_mmap(void *v)
{
return (0);
}
static __inline void
genfs_rel_pages(struct vm_page **pgs, int npages)
{
int i;
for (i = 0; i < npages; i++) {
struct vm_page *pg = pgs[i];
if (pg == NULL)
continue;
if (pg->flags & PG_FAKE) {
pg->flags |= PG_RELEASED;
}
}
uvm_lock_pageq();
uvm_page_unbusy(pgs, npages);
uvm_unlock_pageq();
}
/*
* generic VM getpages routine.
* Return PG_BUSY pages for the given range,
* reading from backing store if necessary.
*/
int
genfs_getpages(void *v)
{
struct vop_getpages_args /* {
struct vnode *a_vp;
voff_t a_offset;
struct vm_page **a_m;
int *a_count;
int a_centeridx;
vm_prot_t a_access_type;
int a_advice;
int a_flags;
} */ *ap = v;
off_t newsize, diskeof, memeof;
off_t offset, origoffset, startoffset, endoffset, raoffset;
daddr_t lbn, blkno;
int s, i, error, npages, orignpages, npgs, run, ridx, pidx, pcount;
int fs_bshift, fs_bsize, dev_bshift;
int flags = ap->a_flags;
size_t bytes, iobytes, tailbytes, totalbytes, skipbytes;
vaddr_t kva;
struct buf *bp, *mbp;
struct vnode *vp = ap->a_vp;
struct vnode *devvp;
struct genfs_node *gp = VTOG(vp);
struct uvm_object *uobj = &vp->v_uobj;
struct vm_page *pg, **pgs, *pgs_onstack[MAX_READ_AHEAD];
int pgs_size;
struct ucred *cred = curproc->p_ucred; /* XXXUBC curlwp */
boolean_t async = (flags & PGO_SYNCIO) == 0;
boolean_t write = (ap->a_access_type & VM_PROT_WRITE) != 0;
boolean_t sawhole = FALSE;
boolean_t overwrite = (flags & PGO_OVERWRITE) != 0;
boolean_t blockalloc = write && (flags & PGO_NOBLOCKALLOC) == 0;
UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist);
UVMHIST_LOG(ubchist, "vp %p off 0x%x/%x count %d",
vp, ap->a_offset >> 32, ap->a_offset, *ap->a_count);
/* XXXUBC temp limit */
if (*ap->a_count > MAX_READ_AHEAD) {
panic("genfs_getpages: too many pages");
}
error = 0;
origoffset = ap->a_offset;
orignpages = *ap->a_count;
GOP_SIZE(vp, vp->v_size, &diskeof, GOP_SIZE_READ);
if (flags & PGO_PASTEOF) {
newsize = MAX(vp->v_size,
origoffset + (orignpages << PAGE_SHIFT));
GOP_SIZE(vp, newsize, &memeof, GOP_SIZE_READ|GOP_SIZE_MEM);
} else {
GOP_SIZE(vp, vp->v_size, &memeof, GOP_SIZE_READ|GOP_SIZE_MEM);
}
KASSERT(ap->a_centeridx >= 0 || ap->a_centeridx <= orignpages);
KASSERT((origoffset & (PAGE_SIZE - 1)) == 0 && origoffset >= 0);
KASSERT(orignpages > 0);
/*
* Bounds-check the request.
*/
if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= memeof) {
if ((flags & PGO_LOCKED) == 0) {
simple_unlock(&uobj->vmobjlock);
}
UVMHIST_LOG(ubchist, "off 0x%x count %d goes past EOF 0x%x",
origoffset, *ap->a_count, memeof,0);
return (EINVAL);
}
/* uobj is locked */
if ((flags & PGO_NOTIMESTAMP) == 0 &&
(vp->v_type == VREG ||
(vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) {
int updflags = 0;
if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) {
updflags = GOP_UPDATE_ACCESSED;
}
if (write) {
updflags |= GOP_UPDATE_MODIFIED;
}
if (updflags != 0) {
GOP_MARKUPDATE(vp, updflags);
}
}
if (write) {
gp->g_dirtygen++;
if ((vp->v_flag & VONWORKLST) == 0) {
vn_syncer_add_to_worklist(vp, filedelay);
}
if ((vp->v_flag & (VWRITEMAP|VWRITEMAPDIRTY)) == VWRITEMAP) {
vp->v_flag |= VWRITEMAPDIRTY;
}
}
/*
* For PGO_LOCKED requests, just return whatever's in memory.
*/
if (flags & PGO_LOCKED) {
uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m,
UFP_NOWAIT|UFP_NOALLOC| (write ? UFP_NORDONLY : 0));
return (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0);
}
/*
* find the requested pages and make some simple checks.
* leave space in the page array for a whole block.
*/
if (vp->v_type == VREG) {
fs_bshift = vp->v_mount->mnt_fs_bshift;
dev_bshift = vp->v_mount->mnt_dev_bshift;
} else {
fs_bshift = DEV_BSHIFT;
dev_bshift = DEV_BSHIFT;
}
fs_bsize = 1 << fs_bshift;
orignpages = MIN(orignpages,
round_page(memeof - origoffset) >> PAGE_SHIFT);
npages = orignpages;
startoffset = origoffset & ~(fs_bsize - 1);
endoffset = round_page((origoffset + (npages << PAGE_SHIFT) +
fs_bsize - 1) & ~(fs_bsize - 1));
endoffset = MIN(endoffset, round_page(memeof));
ridx = (origoffset - startoffset) >> PAGE_SHIFT;
pgs_size = sizeof(struct vm_page *) *
((endoffset - startoffset) >> PAGE_SHIFT);
if (pgs_size > sizeof(pgs_onstack)) {
pgs = malloc(pgs_size, M_DEVBUF, M_NOWAIT | M_ZERO);
if (pgs == NULL) {
simple_unlock(&uobj->vmobjlock);
return (ENOMEM);
}
} else {
pgs = pgs_onstack;
memset(pgs, 0, pgs_size);
}
UVMHIST_LOG(ubchist, "ridx %d npages %d startoff %ld endoff %ld",
ridx, npages, startoffset, endoffset);
if (uvn_findpages(uobj, origoffset, &npages, &pgs[ridx],
async ? UFP_NOWAIT : UFP_ALL) != orignpages) {
KASSERT(async != 0);
genfs_rel_pages(&pgs[ridx], orignpages);
simple_unlock(&uobj->vmobjlock);
if (pgs != pgs_onstack)
free(pgs, M_DEVBUF);
return (EBUSY);
}
/*
* if the pages are already resident, just return them.
*/
for (i = 0; i < npages; i++) {
struct vm_page *pg1 = pgs[ridx + i];
if ((pg1->flags & PG_FAKE) ||
(blockalloc && (pg1->flags & PG_RDONLY))) {
break;
}
}
if (i == npages) {
UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0);
raoffset = origoffset + (orignpages << PAGE_SHIFT);
npages += ridx;
goto raout;
}
/*
* if PGO_OVERWRITE is set, don't bother reading the pages.
*/
if (flags & PGO_OVERWRITE) {
UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0);
for (i = 0; i < npages; i++) {
struct vm_page *pg1 = pgs[ridx + i];
pg1->flags &= ~(PG_RDONLY|PG_CLEAN);
}
npages += ridx;
goto out;
}
/*
* the page wasn't resident and we're not overwriting,
* so we're going to have to do some i/o.
* find any additional pages needed to cover the expanded range.
*/
npages = (endoffset - startoffset) >> PAGE_SHIFT;
if (startoffset != origoffset || npages != orignpages) {
/*
* we need to avoid deadlocks caused by locking
* additional pages at lower offsets than pages we
* already have locked. unlock them all and start over.
*/
genfs_rel_pages(&pgs[ridx], orignpages);
memset(pgs, 0, pgs_size);
UVMHIST_LOG(ubchist, "reset npages start 0x%x end 0x%x",
startoffset, endoffset, 0,0);
npgs = npages;
if (uvn_findpages(uobj, startoffset, &npgs, pgs,
async ? UFP_NOWAIT : UFP_ALL) != npages) {
KASSERT(async != 0);
genfs_rel_pages(pgs, npages);
simple_unlock(&uobj->vmobjlock);
if (pgs != pgs_onstack)
free(pgs, M_DEVBUF);
return (EBUSY);
}
}
simple_unlock(&uobj->vmobjlock);
/*
* read the desired page(s).
*/
totalbytes = npages << PAGE_SHIFT;
bytes = MIN(totalbytes, MAX(diskeof - startoffset, 0));
tailbytes = totalbytes - bytes;
skipbytes = 0;
kva = uvm_pagermapin(pgs, npages,
UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK);
s = splbio();
mbp = pool_get(&bufpool, PR_WAITOK);
splx(s);
BUF_INIT(mbp);
mbp->b_bufsize = totalbytes;
mbp->b_data = (void *)kva;
mbp->b_resid = mbp->b_bcount = bytes;
mbp->b_flags = B_BUSY|B_READ| (async ? B_CALL|B_ASYNC : 0);
mbp->b_iodone = (async ? uvm_aio_biodone : 0);
mbp->b_vp = vp;
/*
* if EOF is in the middle of the range, zero the part past EOF.
* if the page including EOF is not PG_FAKE, skip over it since
* in that case it has valid data that we need to preserve.
*/
if (tailbytes > 0) {
size_t tailstart = bytes;
if ((pgs[bytes >> PAGE_SHIFT]->flags & PG_FAKE) == 0) {
tailstart = round_page(tailstart);
tailbytes -= tailstart - bytes;
}
UVMHIST_LOG(ubchist, "tailbytes %p 0x%x 0x%x",
kva, tailstart, tailbytes,0);
memset((void *)(kva + tailstart), 0, tailbytes);
}
/*
* now loop over the pages, reading as needed.
*/
if (blockalloc) {
lockmgr(&gp->g_glock, LK_EXCLUSIVE, NULL);
} else {
lockmgr(&gp->g_glock, LK_SHARED, NULL);
}
bp = NULL;
for (offset = startoffset;
bytes > 0;
offset += iobytes, bytes -= iobytes) {
/*
* skip pages which don't need to be read.
*/
pidx = (offset - startoffset) >> PAGE_SHIFT;
while ((pgs[pidx]->flags & PG_FAKE) == 0) {
size_t b;
KASSERT((offset & (PAGE_SIZE - 1)) == 0);
if ((pgs[pidx]->flags & PG_RDONLY)) {
sawhole = TRUE;
}
b = MIN(PAGE_SIZE, bytes);
offset += b;
bytes -= b;
skipbytes += b;
pidx++;
UVMHIST_LOG(ubchist, "skipping, new offset 0x%x",
offset, 0,0,0);
if (bytes == 0) {
goto loopdone;
}
}
/*
* bmap the file to find out the blkno to read from and
* how much we can read in one i/o. if bmap returns an error,
* skip the rest of the top-level i/o.
*/
lbn = offset >> fs_bshift;
error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run);
if (error) {
UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%x -> %d\n",
lbn, error,0,0);
skipbytes += bytes;
goto loopdone;
}
/*
* see how many pages can be read with this i/o.
* reduce the i/o size if necessary to avoid
* overwriting pages with valid data.
*/
iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset,
bytes);
if (offset + iobytes > round_page(offset)) {
pcount = 1;
while (pidx + pcount < npages &&
pgs[pidx + pcount]->flags & PG_FAKE) {
pcount++;
}
iobytes = MIN(iobytes, (pcount << PAGE_SHIFT) -
(offset - trunc_page(offset)));
}
/*
* if this block isn't allocated, zero it instead of
* reading it. unless we are going to allocate blocks,
* mark the pages we zeroed PG_RDONLY.
*/
if (blkno < 0) {
int holepages = (round_page(offset + iobytes) -
trunc_page(offset)) >> PAGE_SHIFT;
UVMHIST_LOG(ubchist, "lbn 0x%x -> HOLE", lbn,0,0,0);
sawhole = TRUE;
memset((char *)kva + (offset - startoffset), 0,
iobytes);
skipbytes += iobytes;
for (i = 0; i < holepages; i++) {
if (write) {
pgs[pidx + i]->flags &= ~PG_CLEAN;
}
if (!blockalloc) {
pgs[pidx + i]->flags |= PG_RDONLY;
}
}
continue;
}
/*
* allocate a sub-buf for this piece of the i/o
* (or just use mbp if there's only 1 piece),
* and start it going.
*/
if (offset == startoffset && iobytes == bytes) {
bp = mbp;
} else {
s = splbio();
bp = pool_get(&bufpool, PR_WAITOK);
splx(s);
BUF_INIT(bp);
bp->b_data = (char *)kva + offset - startoffset;
bp->b_resid = bp->b_bcount = iobytes;
bp->b_flags = B_BUSY|B_READ|B_CALL|B_ASYNC;
bp->b_iodone = uvm_aio_biodone1;
bp->b_vp = vp;
bp->b_proc = NULL;
}
bp->b_lblkno = 0;
bp->b_private = mbp;
if (devvp->v_type == VBLK) {
bp->b_dev = devvp->v_rdev;
}
/* adjust physical blkno for partial blocks */
bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >>
dev_bshift);
UVMHIST_LOG(ubchist,
"bp %p offset 0x%x bcount 0x%x blkno 0x%x",
bp, offset, iobytes, bp->b_blkno);
if (async)
BIO_SETPRIO(bp, BPRIO_TIMELIMITED);
else
BIO_SETPRIO(bp, BPRIO_TIMECRITICAL);
VOP_STRATEGY(bp->b_vp, bp);
}
loopdone:
if (skipbytes) {
s = splbio();
if (error) {
mbp->b_flags |= B_ERROR;
mbp->b_error = error;
}
mbp->b_resid -= skipbytes;
if (mbp->b_resid == 0) {
biodone(mbp);
}
splx(s);
}
if (async) {
UVMHIST_LOG(ubchist, "returning 0 (async)",0,0,0,0);
lockmgr(&gp->g_glock, LK_RELEASE, NULL);
if (pgs != pgs_onstack)
free(pgs, M_DEVBUF);
return (0);
}
if (bp != NULL) {
error = biowait(mbp);
}
s = splbio();
pool_put(&bufpool, mbp);
splx(s);
uvm_pagermapout(kva, npages);
raoffset = startoffset + totalbytes;
#ifdef VERIFIED_EXEC
if (!error && !sawhole && !write) {
struct proc *veriexec_p = curlwp->l_proc;
struct vattr veriexec_va;
struct veriexec_hash_entry *vhe;
size_t last_page;
/* XXXEE: try to eliminate this. */
error = VOP_GETATTR(vp, &veriexec_va, veriexec_p->p_ucred,
veriexec_p);
if (error)
goto skip_veriexec;
vhe = veriexec_lookup(veriexec_va.va_fsid,
veriexec_va.va_fileid);
if (vhe == NULL || vhe->page_fp == NULL)
goto skip_veriexec;
last_page = (ridx + npages - 1);
for (i = ridx; i < ridx + npages; i++) {
error = veriexec_page_verify(vhe, &veriexec_va,
pgs[i],
((i == last_page) ? 1
: 0));
if (error)
break;
}
}
skip_veriexec:
#endif /* VERIFIED_EXEC */
/*
* if this we encountered a hole then we have to do a little more work.
* for read faults, we marked the page PG_RDONLY so that future
* write accesses to the page will fault again.
* for write faults, we must make sure that the backing store for
* the page is completely allocated while the pages are locked.
*/
if (!error && sawhole && blockalloc) {
error = GOP_ALLOC(vp, startoffset, npages << PAGE_SHIFT, 0,
cred);
UVMHIST_LOG(ubchist, "gop_alloc off 0x%x/0x%x -> %d",
startoffset, npages << PAGE_SHIFT, error,0);
if (!error) {
for (i = 0; i < npages; i++) {
if (pgs[i] == NULL) {
continue;
}
pgs[i]->flags &= ~(PG_CLEAN|PG_RDONLY);
UVMHIST_LOG(ubchist, "mark dirty pg %p",
pgs[i],0,0,0);
}
}
}
lockmgr(&gp->g_glock, LK_RELEASE, NULL);
simple_lock(&uobj->vmobjlock);
/*
* see if we want to start any readahead.
* XXXUBC for now, just read the next 128k on 64k boundaries.
* this is pretty nonsensical, but it is 50% faster than reading
* just the next 64k.
*/
raout:
if (!error && !async && !write && ((int)raoffset & 0xffff) == 0 &&
PAGE_SHIFT <= 16) {
off_t rasize;
int rapages, err, j, skipped;
/* XXXUBC temp limit, from above */
rapages = MIN(MIN(1 << (16 - PAGE_SHIFT), MAX_READ_AHEAD),
genfs_rapages);
rasize = rapages << PAGE_SHIFT;
for (j = skipped = 0; j < genfs_racount; j++) {
if (raoffset >= memeof)
break;
err = VOP_GETPAGES(vp, raoffset, NULL, &rapages, 0,
VM_PROT_READ, 0, PGO_NOTIMESTAMP);
simple_lock(&uobj->vmobjlock);
if (err) {
if (err != EBUSY ||
skipped++ == genfs_raskip)
break;
}
raoffset += rasize;
rapages = rasize >> PAGE_SHIFT;
}
}
/*
* we're almost done! release the pages...
* for errors, we free the pages.
* otherwise we activate them and mark them as valid and clean.
* also, unbusy pages that were not actually requested.
*/
if (error) {
for (i = 0; i < npages; i++) {
if (pgs[i] == NULL) {
continue;
}
UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x",
pgs[i], pgs[i]->flags, 0,0);
if (pgs[i]->flags & PG_FAKE) {
pgs[i]->flags |= PG_RELEASED;
}
}
uvm_lock_pageq();
uvm_page_unbusy(pgs, npages);
uvm_unlock_pageq();
simple_unlock(&uobj->vmobjlock);
UVMHIST_LOG(ubchist, "returning error %d", error,0,0,0);
if (pgs != pgs_onstack)
free(pgs, M_DEVBUF);
return (error);
}
out:
UVMHIST_LOG(ubchist, "succeeding, npages %d", npages,0,0,0);
uvm_lock_pageq();
for (i = 0; i < npages; i++) {
pg = pgs[i];
if (pg == NULL) {
continue;
}
UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x",
pg, pg->flags, 0,0);
if (pg->flags & PG_FAKE && !overwrite) {
pg->flags &= ~(PG_FAKE);
pmap_clear_modify(pgs[i]);
}
KASSERT(!write || !blockalloc || (pg->flags & PG_RDONLY) == 0);
if (i < ridx || i >= ridx + orignpages || async) {
UVMHIST_LOG(ubchist, "unbusy pg %p offset 0x%x",
pg, pg->offset,0,0);
if (pg->flags & PG_WANTED) {
wakeup(pg);
}
if (pg->flags & PG_FAKE) {
KASSERT(overwrite);
uvm_pagezero(pg);
}
if (pg->flags & PG_RELEASED) {
uvm_pagefree(pg);
continue;
}
uvm_pageactivate(pg);
pg->flags &= ~(PG_WANTED|PG_BUSY|PG_FAKE);
UVM_PAGE_OWN(pg, NULL);
}
}
uvm_unlock_pageq();
simple_unlock(&uobj->vmobjlock);
if (ap->a_m != NULL) {
memcpy(ap->a_m, &pgs[ridx],
orignpages * sizeof(struct vm_page *));
}
if (pgs != pgs_onstack)
free(pgs, M_DEVBUF);
return (0);
}
/*
* generic VM putpages routine.
* Write the given range of pages to backing store.
*
* => "offhi == 0" means flush all pages at or after "offlo".
* => object should be locked by caller. we may _unlock_ the object
* if (and only if) we need to clean a page (PGO_CLEANIT), or
* if PGO_SYNCIO is set and there are pages busy.
* we return with the object locked.
* => if PGO_CLEANIT or PGO_SYNCIO is set, we may block (due to I/O).
* thus, a caller might want to unlock higher level resources
* (e.g. vm_map) before calling flush.
* => if neither PGO_CLEANIT nor PGO_SYNCIO is set, then we will neither
* unlock the object nor block.
* => if PGO_ALLPAGES is set, then all pages in the object will be processed.
* => NOTE: we rely on the fact that the object's memq is a TAILQ and
* that new pages are inserted on the tail end of the list. thus,
* we can make a complete pass through the object in one go by starting
* at the head and working towards the tail (new pages are put in
* front of us).
* => NOTE: we are allowed to lock the page queues, so the caller
* must not be holding the page queue lock.
*
* note on "cleaning" object and PG_BUSY pages:
* this routine is holding the lock on the object. the only time
* that it can run into a PG_BUSY page that it does not own is if
* some other process has started I/O on the page (e.g. either
* a pagein, or a pageout). if the PG_BUSY page is being paged
* in, then it can not be dirty (!PG_CLEAN) because no one has
* had a chance to modify it yet. if the PG_BUSY page is being
* paged out then it means that someone else has already started
* cleaning the page for us (how nice!). in this case, if we
* have syncio specified, then after we make our pass through the
* object we need to wait for the other PG_BUSY pages to clear
* off (i.e. we need to do an iosync). also note that once a
* page is PG_BUSY it must stay in its object until it is un-busyed.
*
* note on page traversal:
* we can traverse the pages in an object either by going down the
* linked list in "uobj->memq", or we can go over the address range
* by page doing hash table lookups for each address. depending
* on how many pages are in the object it may be cheaper to do one
* or the other. we set "by_list" to true if we are using memq.
* if the cost of a hash lookup was equal to the cost of the list
* traversal we could compare the number of pages in the start->stop
* range to the total number of pages in the object. however, it
* seems that a hash table lookup is more expensive than the linked
* list traversal, so we multiply the number of pages in the
* range by an estimate of the relatively higher cost of the hash lookup.
*/
int
genfs_putpages(void *v)
{
struct vop_putpages_args /* {
struct vnode *a_vp;
voff_t a_offlo;
voff_t a_offhi;
int a_flags;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
struct uvm_object *uobj = &vp->v_uobj;
struct simplelock *slock = &uobj->vmobjlock;
off_t startoff = ap->a_offlo;
off_t endoff = ap->a_offhi;
off_t off;
int flags = ap->a_flags;
/* Even for strange MAXPHYS, the shift rounds down to a page */
const int maxpages = MAXPHYS >> PAGE_SHIFT;
int i, s, error, npages, nback;
int freeflag;
struct vm_page *pgs[maxpages], *pg, *nextpg, *tpg, curmp, endmp;
boolean_t wasclean, by_list, needs_clean, yld;
boolean_t async = (flags & PGO_SYNCIO) == 0;
boolean_t pagedaemon = curproc == uvm.pagedaemon_proc;
struct lwp *l = curlwp ? curlwp : &lwp0;
struct genfs_node *gp = VTOG(vp);
int dirtygen;
boolean_t modified = FALSE;
boolean_t cleanall;
UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist);
KASSERT(flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE));
KASSERT((startoff & PAGE_MASK) == 0 && (endoff & PAGE_MASK) == 0);
KASSERT(startoff < endoff || endoff == 0);
UVMHIST_LOG(ubchist, "vp %p pages %d off 0x%x len 0x%x",
vp, uobj->uo_npages, startoff, endoff - startoff);
KASSERT((vp->v_flag & VONWORKLST) != 0 ||
(vp->v_flag & VWRITEMAPDIRTY) == 0);
if (uobj->uo_npages == 0) {
s = splbio();
if (vp->v_flag & VONWORKLST) {
vp->v_flag &= ~VWRITEMAPDIRTY;
if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) {
vp->v_flag &= ~VONWORKLST;
LIST_REMOVE(vp, v_synclist);
}
}
splx(s);
simple_unlock(slock);
return (0);
}
/*
* the vnode has pages, set up to process the request.
*/
error = 0;
s = splbio();
simple_lock(&global_v_numoutput_slock);
wasclean = (vp->v_numoutput == 0);
simple_unlock(&global_v_numoutput_slock);
splx(s);
off = startoff;
if (endoff == 0 || flags & PGO_ALLPAGES) {
endoff = trunc_page(LLONG_MAX);
}
by_list = (uobj->uo_npages <=
((endoff - startoff) >> PAGE_SHIFT) * UVM_PAGE_HASH_PENALTY);
#if !defined(DEBUG)
/*
* if this vnode is known not to have dirty pages,
* don't bother to clean it out.
*/
if ((vp->v_flag & VONWORKLST) == 0) {
if ((flags & (PGO_FREE|PGO_DEACTIVATE)) == 0) {
goto skip_scan;
}
flags &= ~PGO_CLEANIT;
}
#endif /* !defined(DEBUG) */
/*
* start the loop. when scanning by list, hold the last page
* in the list before we start. pages allocated after we start
* will be added to the end of the list, so we can stop at the
* current last page.
*/
cleanall = (flags & PGO_CLEANIT) != 0 && wasclean &&
startoff == 0 && endoff == trunc_page(LLONG_MAX) &&
(vp->v_flag & VONWORKLST) != 0;
dirtygen = gp->g_dirtygen;
freeflag = pagedaemon ? PG_PAGEOUT : PG_RELEASED;
curmp.uobject = uobj;
curmp.offset = (voff_t)-1;
curmp.flags = PG_BUSY;
endmp.uobject = uobj;
endmp.offset = (voff_t)-1;
endmp.flags = PG_BUSY;
if (by_list) {
pg = TAILQ_FIRST(&uobj->memq);
TAILQ_INSERT_TAIL(&uobj->memq, &endmp, listq);
PHOLD(l);
} else {
pg = uvm_pagelookup(uobj, off);
}
nextpg = NULL;
while (by_list || off < endoff) {
/*
* if the current page is not interesting, move on to the next.
*/
KASSERT(pg == NULL || pg->uobject == uobj);
KASSERT(pg == NULL ||
(pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 ||
(pg->flags & PG_BUSY) != 0);
if (by_list) {
if (pg == &endmp) {
break;
}
if (pg->offset < startoff || pg->offset >= endoff ||
pg->flags & (PG_RELEASED|PG_PAGEOUT)) {
if (pg->flags & (PG_RELEASED|PG_PAGEOUT)) {
wasclean = FALSE;
}
pg = TAILQ_NEXT(pg, listq);
continue;
}
off = pg->offset;
} else if (pg == NULL || pg->flags & (PG_RELEASED|PG_PAGEOUT)) {
if (pg != NULL) {
wasclean = FALSE;
}
off += PAGE_SIZE;
if (off < endoff) {
pg = uvm_pagelookup(uobj, off);
}
continue;
}
/*
* if the current page needs to be cleaned and it's busy,
* wait for it to become unbusy.
*/
yld = (l->l_cpu->ci_schedstate.spc_flags &
SPCF_SHOULDYIELD) && !pagedaemon;
if (pg->flags & PG_BUSY || yld) {
UVMHIST_LOG(ubchist, "busy %p", pg,0,0,0);
if (flags & PGO_BUSYFAIL && pg->flags & PG_BUSY) {
UVMHIST_LOG(ubchist, "busyfail %p", pg, 0,0,0);
error = EDEADLK;
break;
}
KASSERT(!pagedaemon);
if (by_list) {
TAILQ_INSERT_BEFORE(pg, &curmp, listq);
UVMHIST_LOG(ubchist, "curmp next %p",
TAILQ_NEXT(&curmp, listq), 0,0,0);
}
if (yld) {
simple_unlock(slock);
preempt(1);
simple_lock(slock);
} else {
pg->flags |= PG_WANTED;
UVM_UNLOCK_AND_WAIT(pg, slock, 0, "genput", 0);
simple_lock(slock);
}
if (by_list) {
UVMHIST_LOG(ubchist, "after next %p",
TAILQ_NEXT(&curmp, listq), 0,0,0);
pg = TAILQ_NEXT(&curmp, listq);
TAILQ_REMOVE(&uobj->memq, &curmp, listq);
} else {
pg = uvm_pagelookup(uobj, off);
}
continue;
}
/*
* if we're freeing, remove all mappings of the page now.
* if we're cleaning, check if the page is needs to be cleaned.
*/
if (flags & PGO_FREE) {
pmap_page_protect(pg, VM_PROT_NONE);
} else if (flags & PGO_CLEANIT) {
/*
* if we still have some hope to pull this vnode off
* from the syncer queue, write-protect the page.
*/
if (cleanall && wasclean &&
gp->g_dirtygen == dirtygen) {
/*
* uobj pages get wired only by uvm_fault
* where uobj is locked.
*/
if (pg->wire_count == 0) {
pmap_page_protect(pg,
VM_PROT_READ|VM_PROT_EXECUTE);
} else {
cleanall = FALSE;
}
}
}
if (flags & PGO_CLEANIT) {
needs_clean = pmap_clear_modify(pg) ||
(pg->flags & PG_CLEAN) == 0;
pg->flags |= PG_CLEAN;
} else {
needs_clean = FALSE;
}
/*
* if we're cleaning, build a cluster.
* the cluster will consist of pages which are currently dirty,
* but they will be returned to us marked clean.
* if not cleaning, just operate on the one page.
*/
if (needs_clean) {
KDASSERT((vp->v_flag & VONWORKLST));
wasclean = FALSE;
memset(pgs, 0, sizeof(pgs));
pg->flags |= PG_BUSY;
UVM_PAGE_OWN(pg, "genfs_putpages");
/*
* first look backward.
*/
npages = MIN(maxpages >> 1, off >> PAGE_SHIFT);
nback = npages;
uvn_findpages(uobj, off - PAGE_SIZE, &nback, &pgs[0],
UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY|UFP_BACKWARD);
if (nback) {
memmove(&pgs[0], &pgs[npages - nback],
nback * sizeof(pgs[0]));
if (npages - nback < nback)
memset(&pgs[nback], 0,
(npages - nback) * sizeof(pgs[0]));
else
memset(&pgs[npages - nback], 0,
nback * sizeof(pgs[0]));
}
/*
* then plug in our page of interest.
*/
pgs[nback] = pg;
/*
* then look forward to fill in the remaining space in
* the array of pages.
*/
npages = maxpages - nback - 1;
uvn_findpages(uobj, off + PAGE_SIZE, &npages,
&pgs[nback + 1],
UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY);
npages += nback + 1;
} else {
pgs[0] = pg;
npages = 1;
nback = 0;
}
/*
* apply FREE or DEACTIVATE options if requested.
*/
if (flags & (PGO_DEACTIVATE|PGO_FREE)) {
uvm_lock_pageq();
}
for (i = 0; i < npages; i++) {
tpg = pgs[i];
KASSERT(tpg->uobject == uobj);
if (by_list && tpg == TAILQ_NEXT(pg, listq))
pg = tpg;
if (tpg->offset < startoff || tpg->offset >= endoff)
continue;
if (flags & PGO_DEACTIVATE &&
(tpg->pqflags & PQ_INACTIVE) == 0 &&
tpg->wire_count == 0) {
(void) pmap_clear_reference(tpg);
uvm_pagedeactivate(tpg);
} else if (flags & PGO_FREE) {
pmap_page_protect(tpg, VM_PROT_NONE);
if (tpg->flags & PG_BUSY) {
tpg->flags |= freeflag;
if (pagedaemon) {
uvmexp.paging++;
uvm_pagedequeue(tpg);
}
} else {
/*
* ``page is not busy''
* implies that npages is 1
* and needs_clean is false.
*/
nextpg = TAILQ_NEXT(tpg, listq);
uvm_pagefree(tpg);
if (pagedaemon)
uvmexp.pdfreed++;
}
}
}
if (flags & (PGO_DEACTIVATE|PGO_FREE)) {
uvm_unlock_pageq();
}
if (needs_clean) {
modified = TRUE;
/*
* start the i/o. if we're traversing by list,
* keep our place in the list with a marker page.
*/
if (by_list) {
TAILQ_INSERT_AFTER(&uobj->memq, pg, &curmp,
listq);
}
simple_unlock(slock);
error = GOP_WRITE(vp, pgs, npages, flags);
simple_lock(slock);
if (by_list) {
pg = TAILQ_NEXT(&curmp, listq);
TAILQ_REMOVE(&uobj->memq, &curmp, listq);
}
if (error) {
break;
}
if (by_list) {
continue;
}
}
/*
* find the next page and continue if there was no error.
*/
if (by_list) {
if (nextpg) {
pg = nextpg;
nextpg = NULL;
} else {
pg = TAILQ_NEXT(pg, listq);
}
} else {
off += (npages - nback) << PAGE_SHIFT;
if (off < endoff) {
pg = uvm_pagelookup(uobj, off);
}
}
}
if (by_list) {
TAILQ_REMOVE(&uobj->memq, &endmp, listq);
PRELE(l);
}
if (modified && (vp->v_flag & VWRITEMAPDIRTY) != 0 &&
(vp->v_type == VREG ||
(vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) {
GOP_MARKUPDATE(vp, GOP_UPDATE_MODIFIED);
}
/*
* if we're cleaning and there was nothing to clean,
* take us off the syncer list. if we started any i/o
* and we're doing sync i/o, wait for all writes to finish.
*/
s = splbio();
if (cleanall && wasclean && gp->g_dirtygen == dirtygen &&
(vp->v_flag & VONWORKLST) != 0) {
vp->v_flag &= ~VWRITEMAPDIRTY;
if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) {
vp->v_flag &= ~VONWORKLST;
LIST_REMOVE(vp, v_synclist);
}
}
splx(s);
#if !defined(DEBUG)
skip_scan:
#endif /* !defined(DEBUG) */
if (!wasclean && !async) {
s = splbio();
/*
* XXX - we want simple_unlock(&global_v_numoutput_slock);
* but the slot in ltsleep() is taken!
* XXX - try to recover from missed wakeups with a timeout..
* must think of something better.
*/
while (vp->v_numoutput != 0) {
vp->v_flag |= VBWAIT;
UVM_UNLOCK_AND_WAIT(&vp->v_numoutput, slock, FALSE,
"genput2", hz);
simple_lock(slock);
}
splx(s);
}
simple_unlock(&uobj->vmobjlock);
return (error);
}
int
genfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags)
{
int s, error, run;
int fs_bshift, dev_bshift;
vaddr_t kva;
off_t eof, offset, startoffset;
size_t bytes, iobytes, skipbytes;
daddr_t lbn, blkno;
struct vm_page *pg;
struct buf *mbp, *bp;
struct vnode *devvp;
boolean_t async = (flags & PGO_SYNCIO) == 0;
UVMHIST_FUNC("genfs_gop_write"); UVMHIST_CALLED(ubchist);
UVMHIST_LOG(ubchist, "vp %p pgs %p npages %d flags 0x%x",
vp, pgs, npages, flags);
GOP_SIZE(vp, vp->v_size, &eof, GOP_SIZE_WRITE);
if (vp->v_type == VREG) {
fs_bshift = vp->v_mount->mnt_fs_bshift;
dev_bshift = vp->v_mount->mnt_dev_bshift;
} else {
fs_bshift = DEV_BSHIFT;
dev_bshift = DEV_BSHIFT;
}
error = 0;
pg = pgs[0];
startoffset = pg->offset;
bytes = MIN(npages << PAGE_SHIFT, eof - startoffset);
skipbytes = 0;
KASSERT(bytes != 0);
kva = uvm_pagermapin(pgs, npages,
UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK);
s = splbio();
simple_lock(&global_v_numoutput_slock);
vp->v_numoutput += 2;
simple_unlock(&global_v_numoutput_slock);
mbp = pool_get(&bufpool, PR_WAITOK);
BUF_INIT(mbp);
UVMHIST_LOG(ubchist, "vp %p mbp %p num now %d bytes 0x%x",
vp, mbp, vp->v_numoutput, bytes);
splx(s);
mbp->b_bufsize = npages << PAGE_SHIFT;
mbp->b_data = (void *)kva;
mbp->b_resid = mbp->b_bcount = bytes;
mbp->b_flags = B_BUSY|B_WRITE|B_AGE| (async ? (B_CALL|B_ASYNC) : 0);
mbp->b_iodone = uvm_aio_biodone;
mbp->b_vp = vp;
bp = NULL;
for (offset = startoffset;
bytes > 0;
offset += iobytes, bytes -= iobytes) {
lbn = offset >> fs_bshift;
error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run);
if (error) {
UVMHIST_LOG(ubchist, "VOP_BMAP() -> %d", error,0,0,0);
skipbytes += bytes;
bytes = 0;
break;
}
iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset,
bytes);
if (blkno == (daddr_t)-1) {
skipbytes += iobytes;
continue;
}
/* if it's really one i/o, don't make a second buf */
if (offset == startoffset && iobytes == bytes) {
bp = mbp;
} else {
s = splbio();
V_INCR_NUMOUTPUT(vp);
bp = pool_get(&bufpool, PR_WAITOK);
UVMHIST_LOG(ubchist, "vp %p bp %p num now %d",
vp, bp, vp->v_numoutput, 0);
splx(s);
BUF_INIT(bp);
bp->b_data = (char *)kva +
(vaddr_t)(offset - pg->offset);
bp->b_resid = bp->b_bcount = iobytes;
bp->b_flags = B_BUSY|B_WRITE|B_CALL|B_ASYNC;
bp->b_iodone = uvm_aio_biodone1;
bp->b_vp = vp;
}
bp->b_lblkno = 0;
bp->b_private = mbp;
if (devvp->v_type == VBLK) {
bp->b_dev = devvp->v_rdev;
}
/* adjust physical blkno for partial blocks */
bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >>
dev_bshift);
UVMHIST_LOG(ubchist,
"vp %p offset 0x%x bcount 0x%x blkno 0x%x",
vp, offset, bp->b_bcount, bp->b_blkno);
if (curproc == uvm.pagedaemon_proc)
BIO_SETPRIO(bp, BPRIO_TIMELIMITED);
else if (async)
BIO_SETPRIO(bp, BPRIO_TIMENONCRITICAL);
else
BIO_SETPRIO(bp, BPRIO_TIMECRITICAL);
VOP_STRATEGY(bp->b_vp, bp);
}
if (skipbytes) {
UVMHIST_LOG(ubchist, "skipbytes %d", skipbytes, 0,0,0);
s = splbio();
if (error) {
mbp->b_flags |= B_ERROR;
mbp->b_error = error;
}
mbp->b_resid -= skipbytes;
if (mbp->b_resid == 0) {
biodone(mbp);
}
splx(s);
}
if (async) {
UVMHIST_LOG(ubchist, "returning 0 (async)", 0,0,0,0);
return (0);
}
UVMHIST_LOG(ubchist, "waiting for mbp %p", mbp,0,0,0);
error = biowait(mbp);
uvm_aio_aiodone(mbp);
UVMHIST_LOG(ubchist, "returning, error %d", error,0,0,0);
return (error);
}
/*
* VOP_PUTPAGES() for vnodes which never have pages.
*/
int
genfs_null_putpages(void *v)
{
struct vop_putpages_args /* {
struct vnode *a_vp;
voff_t a_offlo;
voff_t a_offhi;
int a_flags;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
KASSERT(vp->v_uobj.uo_npages == 0);
simple_unlock(&vp->v_interlock);
return (0);
}
void
genfs_node_init(struct vnode *vp, const struct genfs_ops *ops)
{
struct genfs_node *gp = VTOG(vp);
lockinit(&gp->g_glock, PINOD, "glock", 0, 0);
gp->g_op = ops;
}
void
genfs_size(struct vnode *vp, off_t size, off_t *eobp, int flags)
{
int bsize;
bsize = 1 << vp->v_mount->mnt_fs_bshift;
*eobp = (size + bsize - 1) & ~(bsize - 1);
}
int
genfs_compat_getpages(void *v)
{
struct vop_getpages_args /* {
struct vnode *a_vp;
voff_t a_offset;
struct vm_page **a_m;
int *a_count;
int a_centeridx;
vm_prot_t a_access_type;
int a_advice;
int a_flags;
} */ *ap = v;
off_t origoffset;
struct vnode *vp = ap->a_vp;
struct uvm_object *uobj = &vp->v_uobj;
struct vm_page *pg, **pgs;
vaddr_t kva;
int i, error, orignpages, npages;
struct iovec iov;
struct uio uio;
struct ucred *cred = curproc->p_ucred;
boolean_t write = (ap->a_access_type & VM_PROT_WRITE) != 0;
error = 0;
origoffset = ap->a_offset;
orignpages = *ap->a_count;
pgs = ap->a_m;
if (write && (vp->v_flag & VONWORKLST) == 0) {
vn_syncer_add_to_worklist(vp, filedelay);
}
if (ap->a_flags & PGO_LOCKED) {
uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m,
UFP_NOWAIT|UFP_NOALLOC| (write ? UFP_NORDONLY : 0));
return (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0);
}
if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= vp->v_size) {
simple_unlock(&uobj->vmobjlock);
return (EINVAL);
}
npages = orignpages;
uvn_findpages(uobj, origoffset, &npages, pgs, UFP_ALL);
simple_unlock(&uobj->vmobjlock);
kva = uvm_pagermapin(pgs, npages,
UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK);
for (i = 0; i < npages; i++) {
pg = pgs[i];
if ((pg->flags & PG_FAKE) == 0) {
continue;
}
iov.iov_base = (char *)kva + (i << PAGE_SHIFT);
iov.iov_len = PAGE_SIZE;
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = origoffset + (i << PAGE_SHIFT);
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_rw = UIO_READ;
uio.uio_resid = PAGE_SIZE;
uio.uio_procp = NULL;
/* XXX vn_lock */
error = VOP_READ(vp, &uio, 0, cred);
if (error) {
break;
}
if (uio.uio_resid) {
memset(iov.iov_base, 0, uio.uio_resid);
}
}
uvm_pagermapout(kva, npages);
simple_lock(&uobj->vmobjlock);
uvm_lock_pageq();
for (i = 0; i < npages; i++) {
pg = pgs[i];
if (error && (pg->flags & PG_FAKE) != 0) {
pg->flags |= PG_RELEASED;
} else {
pmap_clear_modify(pg);
uvm_pageactivate(pg);
}
}
if (error) {
uvm_page_unbusy(pgs, npages);
}
uvm_unlock_pageq();
simple_unlock(&uobj->vmobjlock);
return (error);
}
int
genfs_compat_gop_write(struct vnode *vp, struct vm_page **pgs, int npages,
int flags)
{
off_t offset;
struct iovec iov;
struct uio uio;
struct ucred *cred = curproc->p_ucred;
struct buf *bp;
vaddr_t kva;
int s, error;
offset = pgs[0]->offset;
kva = uvm_pagermapin(pgs, npages,
UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK);
iov.iov_base = (void *)kva;
iov.iov_len = npages << PAGE_SHIFT;
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = offset;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_rw = UIO_WRITE;
uio.uio_resid = npages << PAGE_SHIFT;
uio.uio_procp = NULL;
/* XXX vn_lock */
error = VOP_WRITE(vp, &uio, 0, cred);
s = splbio();
V_INCR_NUMOUTPUT(vp);
bp = pool_get(&bufpool, PR_WAITOK);
splx(s);
BUF_INIT(bp);
bp->b_flags = B_BUSY | B_WRITE | B_AGE;
bp->b_vp = vp;
bp->b_lblkno = offset >> vp->v_mount->mnt_fs_bshift;
bp->b_data = (char *)kva;
bp->b_bcount = npages << PAGE_SHIFT;
bp->b_bufsize = npages << PAGE_SHIFT;
bp->b_resid = 0;
if (error) {
bp->b_flags |= B_ERROR;
bp->b_error = error;
}
uvm_aio_aiodone(bp);
return (error);
}
static void
filt_genfsdetach(struct knote *kn)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
/* XXXLUKEM lock the struct? */
SLIST_REMOVE(&vp->v_klist, kn, knote, kn_selnext);
}
static int
filt_genfsread(struct knote *kn, long hint)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
/*
* filesystem is gone, so set the EOF flag and schedule
* the knote for deletion.
*/
if (hint == NOTE_REVOKE) {
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
return (1);
}
/* XXXLUKEM lock the struct? */
kn->kn_data = vp->v_size - kn->kn_fp->f_offset;
return (kn->kn_data != 0);
}
static int
filt_genfsvnode(struct knote *kn, long hint)
{
if (kn->kn_sfflags & hint)
kn->kn_fflags |= hint;
if (hint == NOTE_REVOKE) {
kn->kn_flags |= EV_EOF;
return (1);
}
return (kn->kn_fflags != 0);
}
static const struct filterops genfsread_filtops =
{ 1, NULL, filt_genfsdetach, filt_genfsread };
static const struct filterops genfsvnode_filtops =
{ 1, NULL, filt_genfsdetach, filt_genfsvnode };
int
genfs_kqfilter(void *v)
{
struct vop_kqfilter_args /* {
struct vnode *a_vp;
struct knote *a_kn;
} */ *ap = v;
struct vnode *vp;
struct knote *kn;
vp = ap->a_vp;
kn = ap->a_kn;
switch (kn->kn_filter) {
case EVFILT_READ:
kn->kn_fop = &genfsread_filtops;
break;
case EVFILT_VNODE:
kn->kn_fop = &genfsvnode_filtops;
break;
default:
return (1);
}
kn->kn_hook = vp;
/* XXXLUKEM lock the struct? */
SLIST_INSERT_HEAD(&vp->v_klist, kn, kn_selnext);
return (0);
}