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NetBSD/sys/miscfs/genfs/genfs_vnops.c

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/* $NetBSD: genfs_vnops.c,v 1.39 2001/10/03 14:13:08 enami 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. 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 "opt_nfsserver.h"
#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 <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
int
genfs_poll(v)
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(v)
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;
int wait;
wait = (ap->a_flags & FSYNC_WAIT) != 0;
vflushbuf(vp, wait);
if ((ap->a_flags & FSYNC_DATAONLY) != 0)
return (0);
else
return (VOP_UPDATE(vp, NULL, NULL, wait ? UPDATE_WAIT : 0));
}
int
genfs_seek(v)
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(v)
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(v)
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(v)
void *v;
{
panic("genfs: bad op");
}
/*ARGSUSED*/
int
genfs_nullop(v)
void *v;
{
return (0);
}
/*ARGSUSED*/
int
genfs_einval(v)
void *v;
{
return (EINVAL);
}
/*ARGSUSED*/
int
genfs_eopnotsupp(v)
void *v;
{
return (EOPNOTSUPP);
}
/*
* Called when an fs doesn't support a particular vop but the vop needs to
* vrele, vput, or vunlock passed in vnodes.
*/
int
genfs_eopnotsupp_rele(v)
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;
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);
switch (j) {
case VDESC_VP0_WILLPUT:
vput(vp);
break;
case VDESC_VP0_WILLUNLOCK:
VOP_UNLOCK(vp, 0);
break;
case VDESC_VP0_WILLRELE:
vrele(vp);
break;
}
}
}
return (EOPNOTSUPP);
}
/*ARGSUSED*/
int
genfs_ebadf(v)
void *v;
{
return (EBADF);
}
/* ARGSUSED */
int
genfs_enoioctl(v)
void *v;
{
return (ENOTTY);
}
/*
* Eliminate all activity associated with the requested vnode
* and with all vnodes aliased to the requested vnode.
*/
int
genfs_revoke(v)
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;
simple_unlock(&vp->v_interlock);
tsleep((caddr_t)vp, PINOD, "vop_revokeall", 0);
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(v)
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_lock, ap->a_flags, &vp->v_interlock));
}
/*
* Unlock the node.
*/
int
genfs_unlock(v)
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_lock, ap->a_flags | LK_RELEASE,
&vp->v_interlock));
}
/*
* Return whether or not the node is locked.
*/
int
genfs_islocked(v)
void *v;
{
struct vop_islocked_args /* {
struct vnode *a_vp;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
return (lockstatus(&vp->v_lock));
}
/*
* Stubs to use when there is no locking to be done on the underlying object.
*/
int
genfs_nolock(v)
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(v)
void *v;
{
return (0);
}
int
genfs_noislocked(v)
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(v)
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(v)
void *v;
{
return 0;
}
/*
* generic VM getpages routine.
* Return PG_BUSY pages for the given range,
* reading from backing store if necessary.
*/
int
genfs_getpages(v)
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[16]; /* XXXUBC 16 */
struct ucred *cred = curproc->p_ucred; /* XXXUBC curproc */
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;
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 > 16) {
panic("genfs_getpages: too many pages");
}
error = 0;
origoffset = ap->a_offset;
orignpages = *ap->a_count;
GOP_SIZE(vp, vp->v_size, &diskeof);
if (flags & PGO_PASTEOF) {
newsize = MAX(vp->v_size,
origoffset + (orignpages << PAGE_SHIFT));
GOP_SIZE(vp, newsize, &memeof);
} else {
memeof = diskeof;
}
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;
}
/*
* 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|UFP_NORDONLY);
return ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0;
}
/* vnode is VOP_LOCKed, uobj is locked */
if (write && (vp->v_flag & VONWORKLST) == 0) {
vn_syncer_add_to_worklist(vp, filedelay);
}
/*
* 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;
memset(pgs, 0, sizeof(pgs));
uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], UFP_ALL);
/*
* if the pages are already resident, just return them.
*/
for (i = 0; i < npages; i++) {
struct vm_page *pg = pgs[ridx + i];
if ((pg->flags & PG_FAKE) ||
(write && (pg->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 *pg = pgs[ridx + i];
pg->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.
*/
for (i = 0; i < orignpages; i++) {
struct vm_page *pg = pgs[ridx + i];
if (pg->flags & PG_FAKE) {
pg->flags |= PG_RELEASED;
}
}
uvm_page_unbusy(&pgs[ridx], orignpages);
memset(pgs, 0, sizeof(pgs));
UVMHIST_LOG(ubchist, "reset npages start 0x%x end 0x%x",
startoffset, endoffset, 0,0);
npgs = npages;
uvn_findpages(uobj, startoffset, &npgs, pgs, UFP_ALL);
}
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_WAITOK |
UVMPAGER_MAPIN_READ);
s = splbio();
mbp = pool_get(&bufpool, PR_WAITOK);
splx(s);
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 : 0);
mbp->b_iodone = (async ? uvm_aio_biodone : 0);
mbp->b_vp = vp;
LIST_INIT(&mbp->b_dep);
/*
* 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 (write) {
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|PG_RDONLY)) == 0) {
size_t b;
KASSERT((offset & (PAGE_SIZE - 1)) == 0);
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.
* if this is a read access, 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;
} else {
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);
bp->b_data = (char *)kva + offset - startoffset;
bp->b_resid = bp->b_bcount = iobytes;
bp->b_flags = B_BUSY|B_READ|B_CALL;
bp->b_iodone = uvm_aio_biodone1;
bp->b_vp = vp;
bp->b_proc = NULL;
LIST_INIT(&bp->b_dep);
}
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);
VOP_STRATEGY(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);
return 0;
}
if (bp != NULL) {
error = biowait(mbp);
}
s = splbio();
pool_put(&bufpool, mbp);
splx(s);
uvm_pagermapout(kva, npages);
raoffset = startoffset + totalbytes;
/*
* 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 && write) {
for (i = 0; i < npages; i++) {
if (pgs[i] == NULL) {
continue;
}
pgs[i]->flags &= ~PG_CLEAN;
UVMHIST_LOG(ubchist, "mark dirty pg %p", pgs[i],0,0,0);
}
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);
}
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) {
int racount;
racount = 1 << (16 - PAGE_SHIFT);
(void) VOP_GETPAGES(vp, raoffset, NULL, &racount, 0,
VM_PROT_READ, 0, 0);
simple_lock(&uobj->vmobjlock);
racount = 1 << (16 - PAGE_SHIFT);
(void) VOP_GETPAGES(vp, raoffset + 0x10000, NULL, &racount, 0,
VM_PROT_READ, 0, 0);
simple_lock(&uobj->vmobjlock);
}
/*
* 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);
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]);
}
if (write) {
pg->flags &= ~(PG_RDONLY);
}
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 *));
}
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(v)
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;
off_t startoff = ap->a_offlo;
off_t endoff = ap->a_offhi;
off_t off;
int flags = ap->a_flags;
int n = MAXBSIZE >> PAGE_SHIFT;
int i, s, error, npages, nback;
int freeflag;
struct vm_page *pgs[n], *pg, *nextpg, *tpg, curmp, endmp;
boolean_t wasclean, by_list, needs_clean;
boolean_t async = (flags & PGO_SYNCIO) == 0;
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);
if (uobj->uo_npages == 0) {
if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL &&
(vp->v_flag & VONWORKLST)) {
vp->v_flag &= ~VONWORKLST;
LIST_REMOVE(vp, v_synclist);
}
simple_unlock(&uobj->vmobjlock);
return 0;
}
/*
* the vnode has pages, set up to process the request.
*/
error = 0;
wasclean = TRUE;
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);
/*
* 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.
*/
freeflag = (curproc == uvm.pagedaemon_proc) ? 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(curproc);
} 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)) {
pg = TAILQ_NEXT(pg, listq);
continue;
}
off = pg->offset;
} else if (pg == NULL || pg->flags & (PG_RELEASED|PG_PAGEOUT)) {
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.
*/
if (flags & PGO_FREE) {
pmap_page_protect(pg, VM_PROT_NONE);
}
if (flags & PGO_CLEANIT) {
needs_clean = pmap_clear_modify(pg) ||
(pg->flags & PG_CLEAN) == 0;
pg->flags |= PG_CLEAN;
} else {
needs_clean = FALSE;
}
if (needs_clean && pg->flags & PG_BUSY) {
KASSERT(curproc != uvm.pagedaemon_proc);
UVMHIST_LOG(ubchist, "busy %p", pg,0,0,0);
if (by_list) {
TAILQ_INSERT_BEFORE(pg, &curmp, listq);
UVMHIST_LOG(ubchist, "curmp next %p",
TAILQ_NEXT(&curmp, listq), 0,0,0);
}
pg->flags |= PG_WANTED;
pg->flags &= ~PG_CLEAN;
UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0,
"genput", 0);
simple_lock(&uobj->vmobjlock);
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 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) {
wasclean = FALSE;
memset(pgs, 0, sizeof(pgs));
pg->flags |= PG_BUSY;
UVM_PAGE_OWN(pg, "genfs_putpages");
/*
* first look backward.
*/
npages = MIN(n >> 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]));
}
n -= nback;
/*
* 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 = MIN(n, (endoff - off) >> PAGE_SHIFT) - 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;
}
/*
* 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 (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 (freeflag == PG_PAGEOUT) {
uvmexp.paging++;
uvm_pagedequeue(tpg);
}
} else {
nextpg = TAILQ_NEXT(tpg, listq);
uvm_pagefree(tpg);
}
}
}
if (flags & (PGO_DEACTIVATE|PGO_FREE)) {
uvm_unlock_pageq();
}
if (needs_clean) {
/*
* 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(&uobj->vmobjlock);
error = GOP_WRITE(vp, pgs, npages, flags);
simple_lock(&uobj->vmobjlock);
if (by_list) {
pg = TAILQ_NEXT(&curmp, listq);
TAILQ_REMOVE(&uobj->memq, &curmp, listq);
}
if (error == ENOMEM) {
for (i = 0; i < npages; i++) {
tpg = pgs[i];
if (tpg->flags & PG_PAGEOUT) {
tpg->flags &= ~PG_PAGEOUT;
uvmexp.paging--;
}
tpg->flags &= ~PG_CLEAN;
uvm_pageactivate(tpg);
}
uvm_page_unbusy(pgs, npages);
}
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 += PAGE_SIZE;
if (off < endoff) {
pg = uvm_pagelookup(uobj, off);
}
}
}
if (by_list) {
TAILQ_REMOVE(&uobj->memq, &endmp, listq);
PRELE(curproc);
}
/*
* 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.
*/
if ((flags & PGO_CLEANIT) && wasclean &&
startoff == 0 && endoff == trunc_page(LLONG_MAX) &&
LIST_FIRST(&vp->v_dirtyblkhd) == NULL &&
(vp->v_flag & VONWORKLST)) {
vp->v_flag &= ~VONWORKLST;
LIST_REMOVE(vp, v_synclist);
}
if (!wasclean && !async) {
s = splbio();
while (vp->v_numoutput != 0) {
vp->v_flag |= VBWAIT;
UVM_UNLOCK_AND_WAIT(&vp->v_numoutput, &uobj->vmobjlock,
FALSE, "genput2",0);
simple_lock(&uobj->vmobjlock);
}
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);
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();
vp->v_numoutput += 2;
mbp = pool_get(&bufpool, PR_WAITOK);
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 : 0);
mbp->b_iodone = uvm_aio_biodone;
mbp->b_vp = vp;
LIST_INIT(&mbp->b_dep);
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();
vp->v_numoutput++;
bp = pool_get(&bufpool, PR_WAITOK);
UVMHIST_LOG(ubchist, "vp %p bp %p num now %d",
vp, bp, vp->v_numoutput, 0);
splx(s);
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;
bp->b_iodone = uvm_aio_biodone1;
bp->b_vp = vp;
LIST_INIT(&bp->b_dep);
}
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);
VOP_STRATEGY(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;
}
void
genfs_node_init(struct vnode *vp, 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 bsize;
bsize = 1 << vp->v_mount->mnt_fs_bshift;
*eobp = (size + bsize - 1) & ~(bsize - 1);
}
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