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ffs_vnops.c revision 1.16.2.3
      1 /*	$NetBSD: ffs_vnops.c,v 1.16.2.3 1999/02/25 03:58:29 chs Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1982, 1986, 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)ffs_vnops.c	8.15 (Berkeley) 5/14/95
     36  */
     37 
     38 #if defined(_KERNEL) && !defined(_LKM)
     39 #include "opt_uvm.h"
     40 #include "opt_uvmhist.h"
     41 #endif
     42 
     43 #include <sys/param.h>
     44 #include <sys/systm.h>
     45 #include <sys/resourcevar.h>
     46 #include <sys/kernel.h>
     47 #include <sys/file.h>
     48 #include <sys/stat.h>
     49 #include <sys/buf.h>
     50 #include <sys/proc.h>
     51 #include <sys/conf.h>
     52 #include <sys/mount.h>
     53 #include <sys/vnode.h>
     54 #include <sys/malloc.h>
     55 #include <sys/pool.h>
     56 #include <sys/signalvar.h>
     57 
     58 #include <vm/vm.h>
     59 
     60 #if defined(UVM)
     61 #include <uvm/uvm_extern.h>
     62 #endif
     63 
     64 #include <miscfs/fifofs/fifo.h>
     65 #include <miscfs/genfs/genfs.h>
     66 #include <miscfs/specfs/specdev.h>
     67 
     68 #include <ufs/ufs/quota.h>
     69 #include <ufs/ufs/inode.h>
     70 #include <ufs/ufs/dir.h>
     71 #include <ufs/ufs/ufs_extern.h>
     72 #include <ufs/ufs/ufsmount.h>
     73 
     74 #include <ufs/ffs/fs.h>
     75 #include <ufs/ffs/ffs_extern.h>
     76 
     77 /* Global vfs data structures for ufs. */
     78 int (**ffs_vnodeop_p) __P((void *));
     79 struct vnodeopv_entry_desc ffs_vnodeop_entries[] = {
     80 	{ &vop_default_desc, vn_default_error },
     81 	{ &vop_lookup_desc, ufs_lookup },		/* lookup */
     82 	{ &vop_create_desc, ufs_create },		/* create */
     83 	{ &vop_whiteout_desc, ufs_whiteout },		/* whiteout */
     84 	{ &vop_mknod_desc, ufs_mknod },			/* mknod */
     85 	{ &vop_open_desc, ufs_open },			/* open */
     86 	{ &vop_close_desc, ufs_close },			/* close */
     87 	{ &vop_access_desc, ufs_access },		/* access */
     88 	{ &vop_getattr_desc, ufs_getattr },		/* getattr */
     89 	{ &vop_setattr_desc, ufs_setattr },		/* setattr */
     90 	{ &vop_read_desc, ffs_read },			/* read */
     91 	{ &vop_write_desc, ffs_write },			/* write */
     92 	{ &vop_lease_desc, ufs_lease_check },		/* lease */
     93 	{ &vop_ioctl_desc, ufs_ioctl },			/* ioctl */
     94 	{ &vop_poll_desc, ufs_poll },			/* poll */
     95 	{ &vop_revoke_desc, ufs_revoke },		/* revoke */
     96 	{ &vop_mmap_desc, ufs_mmap },			/* mmap */
     97 	{ &vop_fsync_desc, ffs_fsync },			/* fsync */
     98 	{ &vop_seek_desc, ufs_seek },			/* seek */
     99 	{ &vop_remove_desc, ufs_remove },		/* remove */
    100 	{ &vop_link_desc, ufs_link },			/* link */
    101 	{ &vop_rename_desc, ufs_rename },		/* rename */
    102 	{ &vop_mkdir_desc, ufs_mkdir },			/* mkdir */
    103 	{ &vop_rmdir_desc, ufs_rmdir },			/* rmdir */
    104 	{ &vop_symlink_desc, ufs_symlink },		/* symlink */
    105 	{ &vop_readdir_desc, ufs_readdir },		/* readdir */
    106 	{ &vop_readlink_desc, ufs_readlink },		/* readlink */
    107 	{ &vop_abortop_desc, ufs_abortop },		/* abortop */
    108 	{ &vop_inactive_desc, ufs_inactive },		/* inactive */
    109 	{ &vop_reclaim_desc, ffs_reclaim },		/* reclaim */
    110 	{ &vop_lock_desc, ufs_lock },			/* lock */
    111 	{ &vop_unlock_desc, ufs_unlock },		/* unlock */
    112 	{ &vop_bmap_desc, ufs_bmap },			/* bmap */
    113 	{ &vop_strategy_desc, ufs_strategy },		/* strategy */
    114 	{ &vop_print_desc, ufs_print },			/* print */
    115 	{ &vop_islocked_desc, ufs_islocked },		/* islocked */
    116 	{ &vop_pathconf_desc, ufs_pathconf },		/* pathconf */
    117 	{ &vop_advlock_desc, ufs_advlock },		/* advlock */
    118 	{ &vop_blkatoff_desc, ffs_blkatoff },		/* blkatoff */
    119 	{ &vop_valloc_desc, ffs_valloc },		/* valloc */
    120 	{ &vop_reallocblks_desc, ffs_reallocblks },	/* reallocblks */
    121 	{ &vop_vfree_desc, ffs_vfree },			/* vfree */
    122 	{ &vop_truncate_desc, ffs_truncate },		/* truncate */
    123 	{ &vop_update_desc, ffs_update },		/* update */
    124 	{ &vop_bwrite_desc, vn_bwrite },		/* bwrite */
    125 #ifdef UBC
    126 	{ &vop_getpages_desc, ffs_getpages },		/* getpages */
    127 	{ &vop_putpages_desc, ffs_putpages },		/* putpages */
    128 #endif
    129 	{ NULL, NULL }
    130 };
    131 struct vnodeopv_desc ffs_vnodeop_opv_desc =
    132 	{ &ffs_vnodeop_p, ffs_vnodeop_entries };
    133 
    134 int (**ffs_specop_p) __P((void *));
    135 struct vnodeopv_entry_desc ffs_specop_entries[] = {
    136 	{ &vop_default_desc, vn_default_error },
    137 	{ &vop_lookup_desc, spec_lookup },		/* lookup */
    138 	{ &vop_create_desc, spec_create },		/* create */
    139 	{ &vop_mknod_desc, spec_mknod },		/* mknod */
    140 	{ &vop_open_desc, spec_open },			/* open */
    141 	{ &vop_close_desc, ufsspec_close },		/* close */
    142 	{ &vop_access_desc, ufs_access },		/* access */
    143 	{ &vop_getattr_desc, ufs_getattr },		/* getattr */
    144 	{ &vop_setattr_desc, ufs_setattr },		/* setattr */
    145 	{ &vop_read_desc, ufsspec_read },		/* read */
    146 	{ &vop_write_desc, ufsspec_write },		/* write */
    147 	{ &vop_lease_desc, spec_lease_check },		/* lease */
    148 	{ &vop_ioctl_desc, spec_ioctl },		/* ioctl */
    149 	{ &vop_poll_desc, spec_poll },			/* poll */
    150 	{ &vop_revoke_desc, spec_revoke },		/* revoke */
    151 	{ &vop_mmap_desc, spec_mmap },			/* mmap */
    152 	{ &vop_fsync_desc, ffs_fsync },			/* fsync */
    153 	{ &vop_seek_desc, spec_seek },			/* seek */
    154 	{ &vop_remove_desc, spec_remove },		/* remove */
    155 	{ &vop_link_desc, spec_link },			/* link */
    156 	{ &vop_rename_desc, spec_rename },		/* rename */
    157 	{ &vop_mkdir_desc, spec_mkdir },		/* mkdir */
    158 	{ &vop_rmdir_desc, spec_rmdir },		/* rmdir */
    159 	{ &vop_symlink_desc, spec_symlink },		/* symlink */
    160 	{ &vop_readdir_desc, spec_readdir },		/* readdir */
    161 	{ &vop_readlink_desc, spec_readlink },		/* readlink */
    162 	{ &vop_abortop_desc, spec_abortop },		/* abortop */
    163 	{ &vop_inactive_desc, ufs_inactive },		/* inactive */
    164 	{ &vop_reclaim_desc, ffs_reclaim },		/* reclaim */
    165 	{ &vop_lock_desc, ufs_lock },			/* lock */
    166 	{ &vop_unlock_desc, ufs_unlock },		/* unlock */
    167 	{ &vop_bmap_desc, spec_bmap },			/* bmap */
    168 	{ &vop_strategy_desc, spec_strategy },		/* strategy */
    169 	{ &vop_print_desc, ufs_print },			/* print */
    170 	{ &vop_islocked_desc, ufs_islocked },		/* islocked */
    171 	{ &vop_pathconf_desc, spec_pathconf },		/* pathconf */
    172 	{ &vop_advlock_desc, spec_advlock },		/* advlock */
    173 	{ &vop_blkatoff_desc, spec_blkatoff },		/* blkatoff */
    174 	{ &vop_valloc_desc, spec_valloc },		/* valloc */
    175 	{ &vop_reallocblks_desc, spec_reallocblks },	/* reallocblks */
    176 	{ &vop_vfree_desc, ffs_vfree },			/* vfree */
    177 	{ &vop_truncate_desc, spec_truncate },		/* truncate */
    178 	{ &vop_update_desc, ffs_update },		/* update */
    179 	{ &vop_bwrite_desc, vn_bwrite },		/* bwrite */
    180 	{ (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
    181 };
    182 struct vnodeopv_desc ffs_specop_opv_desc =
    183 	{ &ffs_specop_p, ffs_specop_entries };
    184 
    185 int (**ffs_fifoop_p) __P((void *));
    186 struct vnodeopv_entry_desc ffs_fifoop_entries[] = {
    187 	{ &vop_default_desc, vn_default_error },
    188 	{ &vop_lookup_desc, fifo_lookup },		/* lookup */
    189 	{ &vop_create_desc, fifo_create },		/* create */
    190 	{ &vop_mknod_desc, fifo_mknod },		/* mknod */
    191 	{ &vop_open_desc, fifo_open },			/* open */
    192 	{ &vop_close_desc, ufsfifo_close },		/* close */
    193 	{ &vop_access_desc, ufs_access },		/* access */
    194 	{ &vop_getattr_desc, ufs_getattr },		/* getattr */
    195 	{ &vop_setattr_desc, ufs_setattr },		/* setattr */
    196 	{ &vop_read_desc, ufsfifo_read },		/* read */
    197 	{ &vop_write_desc, ufsfifo_write },		/* write */
    198 	{ &vop_lease_desc, fifo_lease_check },		/* lease */
    199 	{ &vop_ioctl_desc, fifo_ioctl },		/* ioctl */
    200 	{ &vop_poll_desc, fifo_poll },			/* poll */
    201 	{ &vop_revoke_desc, fifo_revoke },		/* revoke */
    202 	{ &vop_mmap_desc, fifo_mmap },			/* mmap */
    203 	{ &vop_fsync_desc, ffs_fsync },			/* fsync */
    204 	{ &vop_seek_desc, fifo_seek },			/* seek */
    205 	{ &vop_remove_desc, fifo_remove },		/* remove */
    206 	{ &vop_link_desc, fifo_link },			/* link */
    207 	{ &vop_rename_desc, fifo_rename },		/* rename */
    208 	{ &vop_mkdir_desc, fifo_mkdir },		/* mkdir */
    209 	{ &vop_rmdir_desc, fifo_rmdir },		/* rmdir */
    210 	{ &vop_symlink_desc, fifo_symlink },		/* symlink */
    211 	{ &vop_readdir_desc, fifo_readdir },		/* readdir */
    212 	{ &vop_readlink_desc, fifo_readlink },		/* readlink */
    213 	{ &vop_abortop_desc, fifo_abortop },		/* abortop */
    214 	{ &vop_inactive_desc, ufs_inactive },		/* inactive */
    215 	{ &vop_reclaim_desc, ffs_reclaim },		/* reclaim */
    216 	{ &vop_lock_desc, ufs_lock },			/* lock */
    217 	{ &vop_unlock_desc, ufs_unlock },		/* unlock */
    218 	{ &vop_bmap_desc, fifo_bmap },			/* bmap */
    219 	{ &vop_strategy_desc, fifo_strategy },		/* strategy */
    220 	{ &vop_print_desc, ufs_print },			/* print */
    221 	{ &vop_islocked_desc, ufs_islocked },		/* islocked */
    222 	{ &vop_pathconf_desc, fifo_pathconf },		/* pathconf */
    223 	{ &vop_advlock_desc, fifo_advlock },		/* advlock */
    224 	{ &vop_blkatoff_desc, fifo_blkatoff },		/* blkatoff */
    225 	{ &vop_valloc_desc, fifo_valloc },		/* valloc */
    226 	{ &vop_reallocblks_desc, fifo_reallocblks },	/* reallocblks */
    227 	{ &vop_vfree_desc, ffs_vfree },			/* vfree */
    228 	{ &vop_truncate_desc, fifo_truncate },		/* truncate */
    229 	{ &vop_update_desc, ffs_update },		/* update */
    230 	{ &vop_bwrite_desc, vn_bwrite },		/* bwrite */
    231 	{ (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
    232 };
    233 struct vnodeopv_desc ffs_fifoop_opv_desc =
    234 	{ &ffs_fifoop_p, ffs_fifoop_entries };
    235 
    236 int doclusterread = 1;
    237 int doclusterwrite = 1;
    238 
    239 #include <ufs/ufs/ufs_readwrite.c>
    240 
    241 /*
    242  * Reclaim an inode so that it can be used for other purposes.
    243  */
    244 int
    245 ffs_reclaim(v)
    246 	void *v;
    247 {
    248 	struct vop_reclaim_args /* {
    249 		struct vnode *a_vp;
    250 		struct proc *a_p;
    251 	} */ *ap = v;
    252 	register struct vnode *vp = ap->a_vp;
    253 	int error;
    254 
    255 	if ((error = ufs_reclaim(vp, ap->a_p)) != 0)
    256 		return (error);
    257 
    258 	/*
    259 	 * XXX MFS ends up here, too, to free an inode.  Should we create
    260 	 * XXX a separate pool for MFS inodes?
    261 	 */
    262 	pool_put(&ffs_inode_pool, vp->v_data);
    263 	vp->v_data = NULL;
    264 	return (0);
    265 }
    266 
    267 #ifdef UBC
    268 #include <uvm/uvm.h>
    269 
    270 int
    271 ffs_getpages(v)
    272 	void *v;
    273 {
    274 	struct vop_getpages_args /* {
    275 		struct vnode *a_vp;
    276 		vaddr_t a_offset;
    277 		vm_page_t *a_m;
    278 		int *a_count;
    279 		int a_centeridx;
    280 		vm_prot_t a_access_type;
    281 		int a_advice;
    282 		int a_flags;
    283 	} */ *ap = v;
    284 
    285 	int i, error, npages;
    286 	vm_page_t m;
    287 	vaddr_t kva;
    288 	struct buf tmpbuf, *bp;
    289 	struct vnode *vp = ap->a_vp;
    290 	struct uvm_object *uobj = &vp->v_uvm.u_obj;
    291 	struct inode *ip = VTOI(vp);
    292 	struct fs *fs = ip->i_fs;
    293 	UVMHIST_FUNC("ffs_getpages"); UVMHIST_CALLED(ubchist);
    294 
    295 #ifdef DIAGNOSTIC
    296 	if (ap->a_centeridx < 0 || ap->a_centeridx > *ap->a_count) {
    297 		panic("ffs_getpages: centeridx %d out of range",
    298 		      ap->a_centeridx);
    299 	}
    300 #endif
    301 
    302 	if (ap->a_flags & PGO_LOCKED) {
    303 		uvn_findpages(uobj, ap->a_offset, ap->a_count, ap->a_m,
    304 			      UFP_NOWAIT|UFP_NOALLOC);
    305 
    306 		/* XXX PGO_ALLPAGES? */
    307 		return ap->a_m[ap->a_centeridx] == NULL ?
    308 			VM_PAGER_UNLOCK : VM_PAGER_OK;
    309 	}
    310 
    311 	/* vnode is VOP_LOCKed, uobj is locked */
    312 
    313 	/*
    314 	 * XXX
    315 	 * first see if center page already exists.
    316 	 * this is needed because ubc_fault() doesn't
    317 	 * do a PGO_LOCKED call first.
    318 	 * if the page exists, return it.
    319 	 */
    320 
    321 	npages = 1;
    322 	uvn_findpages(uobj, ap->a_offset + (ap->a_centeridx << PAGE_SHIFT),
    323 		      &npages, &ap->a_m[ap->a_centeridx], UFP_NOALLOC);
    324 	if (npages == 1) {
    325 		simple_unlock(&uobj->vmobjlock);
    326 		return VM_PAGER_OK;
    327 	}
    328 
    329 	npages = 1;
    330 	uvn_findpages(uobj, ap->a_offset, &npages, ap->a_m, 0);
    331 	m = ap->a_m[ap->a_centeridx];
    332 
    333 	simple_unlock(&uobj->vmobjlock);
    334 
    335 	if ((m->flags & PG_FAKE) == 0) {
    336 		UVMHIST_LOG(ubchist, "page was valid",0,0,0,0);
    337 		return VM_PAGER_OK;
    338 	}
    339 
    340 	bp = &tmpbuf;
    341 	bzero(bp, sizeof *bp);
    342 
    343 	bp->b_lblkno = lblkno(fs, m->offset);
    344 	if (m->blkno == 0) {
    345 		error = VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL);
    346 		if (error) {
    347 UVMHIST_LOG(ubchist, "VOP_BMAP error %d", error,0,0,0);
    348 			return (error);
    349 		}
    350 UVMHIST_LOG(ubchist, "VOP_BMAP gave 0x%x", bp->b_blkno,0,0,0);
    351 		if (bp->b_blkno == (daddr_t)-1) {
    352 
    353 			/*
    354 			 * XXX pre-allocate blocks here someday?
    355 			 * ... only for write accesses.
    356 			 * for read accesses we can skip the block allocation
    357 			 * if we can arrange to be called again
    358 			 * when a subsequent write access occurs.
    359 			 * needs support in uvm_fault().
    360 			 */
    361 			uvm_pagezero(m);
    362 			m->flags &= ~(PG_FAKE);
    363 			pmap_clear_modify(PMAP_PGARG(m));
    364 			pmap_clear_reference(PMAP_PGARG(m));
    365 			return VM_PAGER_OK;
    366 		}
    367 	}
    368 
    369 	/* adjust physical blkno for partial blocks */
    370 	bp->b_blkno += (m->offset - lblktosize(fs, bp->b_lblkno)) >> DEV_BSHIFT;
    371 	m->blkno = bp->b_blkno;
    372 
    373 UVMHIST_LOG(ubchist, "vp %p lblkno 0x%x blkno 0x%x",
    374 	    vp, bp->b_lblkno, bp->b_blkno, 0);
    375 
    376 	/*
    377 	 * don't bother reading the pages if we're just going to
    378 	 * overwrite them.
    379 	 */
    380 	if (ap->a_flags & PGO_OVERWRITE) {
    381 		for (i = 0; i < *ap->a_count; i++) {
    382 
    383 			/* XXX for now, zero the pages */
    384 			if (ap->a_m[i]->flags & PG_FAKE) {
    385 				uvm_pagezero(ap->a_m[i]);
    386 				ap->a_m[i]->flags &= ~(PG_FAKE);
    387 			}
    388 		}
    389 		return VM_PAGER_OK;
    390 	}
    391 
    392 	kva = uvm_pagermapin(ap->a_m, *ap->a_count, NULL, M_WAITOK);
    393 	if (kva == 0) {
    394 		/* XXX unbusy pages */
    395 		return VM_PAGER_AGAIN;
    396 	}
    397 
    398 	bp->b_bufsize = PAGE_SIZE;
    399 	bp->b_data = (void *)kva;
    400 	bp->b_bcount = bp->b_lblkno < 0 ? bp->b_bufsize :
    401 		min(bp->b_bufsize,
    402 		    fragroundup(fs, vp->v_uvm.u_size - m->offset));
    403 	bp->b_vp = vp;
    404 	bp->b_flags = B_BUSY|B_READ;
    405 
    406 UVMHIST_LOG(ubchist, "bp %p vp %p blkno 0x%x", bp, vp, bp->b_lblkno, 0);
    407 
    408 	VOP_STRATEGY(bp);
    409 	error = biowait(bp);
    410 
    411 UVMHIST_LOG(ubchist, "error %d", error,0,0,0);
    412 
    413 	uvm_pagermapout(kva, *ap->a_count);
    414 
    415 	if (error) {
    416 		simple_lock(&uobj->vmobjlock);
    417 		if (m->flags & PG_WANTED)
    418 			wakeup(m);
    419 		m->flags &= ~(PG_WANTED|PG_BUSY);
    420 		UVM_PAGE_OWN(m, NULL);
    421 		uvm_lock_pageq();
    422 		uvm_pagefree(m);
    423 		uvm_unlock_pageq();
    424 		simple_unlock(&uobj->vmobjlock);
    425 	} else {
    426 		m->flags &= ~(PG_FAKE);
    427 		pmap_clear_modify(PMAP_PGARG(m));
    428 	}
    429 
    430 	return error ? VM_PAGER_ERROR : VM_PAGER_OK;
    431 }
    432 
    433 /*
    434  * Vnode op for VM putpages.
    435  */
    436 int
    437 ffs_putpages(v)
    438 	void *v;
    439 {
    440 	struct vop_putpages_args /* {
    441 		struct vnode *a_vp;
    442 		struct vm_page **a_m;
    443 		int a_count;
    444 		int a_sync;
    445 		int *a_rtvals;
    446 	} */ *ap = v;
    447 
    448 	int s, error;
    449 	vaddr_t kva, offset;
    450 	struct vm_page *pg;
    451 	struct buf tmpbuf, *bp;
    452 	struct vnode *vp = ap->a_vp;
    453 	struct inode *ip = VTOI(vp);
    454 	struct fs *fs = ip->i_fs;
    455 	struct ucred *cred = curproc->p_ucred;	/* XXX curproc */
    456 	UVMHIST_FUNC("ffs_putpages"); UVMHIST_CALLED(ubchist);
    457 
    458 	pg = ap->a_m[0];
    459 
    460 #ifdef DIAGNOSTIC
    461 	if (ap->a_count > 1) {
    462 		int i;
    463 
    464 		for (i = 1; i < ap->a_count; i++) {
    465 			if (ap->a_m[i]->blkno !=
    466 			    pg->blkno + i * (PAGE_SIZE >> DEV_BSHIFT)) {
    467 				panic("ffs_putpages: pg %p %p not clusterable",
    468 				      pg, ap->a_m[i]);
    469 			}
    470 		}
    471 	}
    472 #endif
    473 
    474 	kva = uvm_pagermapin(ap->a_m, ap->a_count, NULL, M_WAITOK);
    475 	if (kva == 0) {
    476 		return VM_PAGER_AGAIN;
    477 	}
    478 
    479 	if (ap->a_sync) {
    480 		bp = &tmpbuf;
    481 		bzero(bp, sizeof *bp);
    482 	}
    483 	else {
    484 		struct uvm_aiobuf *abp = pool_get(uvm_aiobuf_pool, PR_WAITOK);
    485 		abp->aio.aiodone = uvm_aio_aiodone;
    486 		abp->aio.kva = kva;
    487 		abp->aio.npages = ap->a_count;
    488 		abp->aio.pd_ptr = abp;
    489 		bp = &abp->buf;
    490 		bzero(bp, sizeof *bp);
    491 		bp->b_flags = B_CALL|B_ASYNC;
    492 		bp->b_iodone = uvm_aio_biodone;
    493 	}
    494 
    495 	offset = pg->offset;
    496 	bp->b_bufsize = ap->a_count << PAGE_SHIFT;
    497 	bp->b_data = (void *)kva;
    498 	bp->b_lblkno = lblkno(fs, offset);
    499 	bp->b_bcount = min(bp->b_bufsize,
    500 			   fragroundup(fs, vp->v_uvm.u_size - offset));
    501 	bp->b_flags |= B_BUSY|B_WRITE;
    502 	bp->b_vp = vp;
    503 
    504 	/*
    505 	 * if the blkno wasn't set in the page, do a bmap to find it.
    506 	 * this should only happen if the block is unallocated.
    507 	 * we'll always want to set the page's blkno if it's allocated
    508 	 * to help prevent memory deadlocks.  we probably even want to
    509 	 * allocate blocks in VOP_GETPAGES() for this same reason.
    510 	 *
    511 	 * once we switch to doing that, the page should always have a blkno.
    512 	 * but for now, we'll handle allocating blocks here too.
    513 	 *
    514 	 * XXX this doesn't handle blocksizes smaller than PAGE_SIZE.
    515 	 */
    516 
    517 	bp->b_blkno = pg->blkno;
    518 	if (bp->b_blkno == 0) {
    519 		int bsize;
    520 
    521 #ifdef DEBUG
    522 		error = VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL);
    523 		if (error) {
    524 			goto out;
    525 		}
    526 		if (bp->b_blkno != (daddr_t)-1) {
    527 			panic("ffs_putpage: page %p has blkno 0, not %d\n",
    528 			      pg, bp->b_blkno);
    529 		}
    530 #endif
    531 		bsize = blksize(fs, ip, lblkno(fs, offset));
    532 		error = ffs_balloc(ip, bp->b_lblkno, bsize, cred, NULL,
    533 				   &bp->b_blkno, 0, NULL);
    534 		if (error) {
    535 			UVMHIST_LOG(ubchist, "ffs_balloc -> %d", error, 0,0,0);
    536 			goto out;
    537 		}
    538 
    539 		/* adjust physical blkno for partial blocks */
    540 		bp->b_blkno += ((offset - lblktosize(fs, bp->b_lblkno))
    541 				>> DEV_BSHIFT);
    542 		pg->blkno = bp->b_blkno;
    543 	}
    544 
    545 	UVMHIST_LOG(ubchist, "pg %p vp %p lblkno 0x%x blkno 0x%x",
    546 		    pg, vp, bp->b_lblkno, bp->b_blkno);
    547 
    548 	s = splbio();
    549 	vp->v_numoutput++;
    550 	splx(s);
    551 
    552 	VOP_STRATEGY(bp);
    553 	if (!ap->a_sync) {
    554 		return VM_PAGER_PEND;
    555 	}
    556 
    557 	error = biowait(bp);
    558 
    559 out:
    560 UVMHIST_LOG(ubchist, "error %d", error,0,0,0);
    561 	uvm_pagermapout(kva, ap->a_count);
    562 
    563 	return error ? VM_PAGER_ERROR : VM_PAGER_OK;
    564 }
    565 #endif
    566