xref: /dragonfly/sys/vfs/devfs/devfs_vnops.c (revision 77b0c609)
1 /*
2  * (MPSAFE)
3  *
4  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
5  *
6  * This code is derived from software contributed to The DragonFly Project
7  * by Alex Hornung <ahornung@gmail.com>
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  * 3. Neither the name of The DragonFly Project nor the names of its
20  *    contributors may be used to endorse or promote products derived
21  *    from this software without specific, prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
26  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
27  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/time.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/fcntl.h>
42 #include <sys/proc.h>
43 #include <sys/priv.h>
44 #include <sys/signalvar.h>
45 #include <sys/vnode.h>
46 #include <sys/uio.h>
47 #include <sys/mount.h>
48 #include <sys/file.h>
49 #include <sys/fcntl.h>
50 #include <sys/namei.h>
51 #include <sys/dirent.h>
52 #include <sys/malloc.h>
53 #include <sys/stat.h>
54 #include <sys/reg.h>
55 #include <vm/vm_pager.h>
56 #include <vm/vm_zone.h>
57 #include <vm/vm_object.h>
58 #include <sys/filio.h>
59 #include <sys/ttycom.h>
60 #include <sys/tty.h>
61 #include <sys/diskslice.h>
62 #include <sys/sysctl.h>
63 #include <sys/devfs.h>
64 #include <sys/pioctl.h>
65 #include <vfs/fifofs/fifo.h>
66 
67 #include <machine/limits.h>
68 
69 #include <sys/buf2.h>
70 #include <sys/sysref2.h>
71 #include <sys/mplock2.h>
72 #include <vm/vm_page2.h>
73 
74 MALLOC_DECLARE(M_DEVFS);
75 #define DEVFS_BADOP	(void *)devfs_vop_badop
76 
77 static int devfs_vop_badop(struct vop_generic_args *);
78 static int devfs_vop_access(struct vop_access_args *);
79 static int devfs_vop_inactive(struct vop_inactive_args *);
80 static int devfs_vop_reclaim(struct vop_reclaim_args *);
81 static int devfs_vop_readdir(struct vop_readdir_args *);
82 static int devfs_vop_getattr(struct vop_getattr_args *);
83 static int devfs_vop_setattr(struct vop_setattr_args *);
84 static int devfs_vop_readlink(struct vop_readlink_args *);
85 static int devfs_vop_print(struct vop_print_args *);
86 
87 static int devfs_vop_nresolve(struct vop_nresolve_args *);
88 static int devfs_vop_nlookupdotdot(struct vop_nlookupdotdot_args *);
89 static int devfs_vop_nmkdir(struct vop_nmkdir_args *);
90 static int devfs_vop_nsymlink(struct vop_nsymlink_args *);
91 static int devfs_vop_nrmdir(struct vop_nrmdir_args *);
92 static int devfs_vop_nremove(struct vop_nremove_args *);
93 
94 static int devfs_spec_open(struct vop_open_args *);
95 static int devfs_spec_close(struct vop_close_args *);
96 static int devfs_spec_fsync(struct vop_fsync_args *);
97 
98 static int devfs_spec_read(struct vop_read_args *);
99 static int devfs_spec_write(struct vop_write_args *);
100 static int devfs_spec_ioctl(struct vop_ioctl_args *);
101 static int devfs_spec_kqfilter(struct vop_kqfilter_args *);
102 static int devfs_spec_strategy(struct vop_strategy_args *);
103 static void devfs_spec_strategy_done(struct bio *);
104 static int devfs_spec_freeblks(struct vop_freeblks_args *);
105 static int devfs_spec_bmap(struct vop_bmap_args *);
106 static int devfs_spec_advlock(struct vop_advlock_args *);
107 static void devfs_spec_getpages_iodone(struct bio *);
108 static int devfs_spec_getpages(struct vop_getpages_args *);
109 
110 static int devfs_fo_close(struct file *);
111 static int devfs_fo_read(struct file *, struct uio *, struct ucred *, int);
112 static int devfs_fo_write(struct file *, struct uio *, struct ucred *, int);
113 static int devfs_fo_stat(struct file *, struct stat *, struct ucred *);
114 static int devfs_fo_kqfilter(struct file *, struct knote *);
115 static int devfs_fo_ioctl(struct file *, u_long, caddr_t,
116 				struct ucred *, struct sysmsg *);
117 static __inline int sequential_heuristic(struct uio *, struct file *);
118 
119 extern struct lock devfs_lock;
120 
121 /*
122  * devfs vnode operations for regular files.  All vnode ops are MPSAFE.
123  */
124 struct vop_ops devfs_vnode_norm_vops = {
125 	.vop_default =		vop_defaultop,
126 	.vop_access =		devfs_vop_access,
127 	.vop_advlock =		DEVFS_BADOP,
128 	.vop_bmap =		DEVFS_BADOP,
129 	.vop_close =		vop_stdclose,
130 	.vop_getattr =		devfs_vop_getattr,
131 	.vop_inactive =		devfs_vop_inactive,
132 	.vop_ncreate =		DEVFS_BADOP,
133 	.vop_nresolve =		devfs_vop_nresolve,
134 	.vop_nlookupdotdot =	devfs_vop_nlookupdotdot,
135 	.vop_nlink =		DEVFS_BADOP,
136 	.vop_nmkdir =		devfs_vop_nmkdir,
137 	.vop_nmknod =		DEVFS_BADOP,
138 	.vop_nremove =		devfs_vop_nremove,
139 	.vop_nrename =		DEVFS_BADOP,
140 	.vop_nrmdir =		devfs_vop_nrmdir,
141 	.vop_nsymlink =		devfs_vop_nsymlink,
142 	.vop_open =		vop_stdopen,
143 	.vop_pathconf =		vop_stdpathconf,
144 	.vop_print =		devfs_vop_print,
145 	.vop_read =		DEVFS_BADOP,
146 	.vop_readdir =		devfs_vop_readdir,
147 	.vop_readlink =		devfs_vop_readlink,
148 	.vop_reclaim =		devfs_vop_reclaim,
149 	.vop_setattr =		devfs_vop_setattr,
150 	.vop_write =		DEVFS_BADOP,
151 	.vop_ioctl =		DEVFS_BADOP
152 };
153 
154 /*
155  * devfs vnode operations for character devices.  All vnode ops are MPSAFE.
156  */
157 struct vop_ops devfs_vnode_dev_vops = {
158 	.vop_default =		vop_defaultop,
159 	.vop_access =		devfs_vop_access,
160 	.vop_advlock =		devfs_spec_advlock,
161 	.vop_bmap =		devfs_spec_bmap,
162 	.vop_close =		devfs_spec_close,
163 	.vop_freeblks =		devfs_spec_freeblks,
164 	.vop_fsync =		devfs_spec_fsync,
165 	.vop_getattr =		devfs_vop_getattr,
166 	.vop_getpages =		devfs_spec_getpages,
167 	.vop_inactive =		devfs_vop_inactive,
168 	.vop_open =		devfs_spec_open,
169 	.vop_pathconf =		vop_stdpathconf,
170 	.vop_print =		devfs_vop_print,
171 	.vop_kqfilter =		devfs_spec_kqfilter,
172 	.vop_read =		devfs_spec_read,
173 	.vop_readdir =		DEVFS_BADOP,
174 	.vop_readlink =		DEVFS_BADOP,
175 	.vop_reclaim =		devfs_vop_reclaim,
176 	.vop_setattr =		devfs_vop_setattr,
177 	.vop_strategy =		devfs_spec_strategy,
178 	.vop_write =		devfs_spec_write,
179 	.vop_ioctl =		devfs_spec_ioctl
180 };
181 
182 /*
183  * devfs file pointer operations.  All fileops are MPSAFE.
184  */
185 struct vop_ops *devfs_vnode_dev_vops_p = &devfs_vnode_dev_vops;
186 
187 struct fileops devfs_dev_fileops = {
188 	.fo_read	= devfs_fo_read,
189 	.fo_write	= devfs_fo_write,
190 	.fo_ioctl	= devfs_fo_ioctl,
191 	.fo_kqfilter	= devfs_fo_kqfilter,
192 	.fo_stat	= devfs_fo_stat,
193 	.fo_close	= devfs_fo_close,
194 	.fo_shutdown	= nofo_shutdown
195 };
196 
197 /*
198  * These two functions are possibly temporary hacks for devices (aka
199  * the pty code) which want to control the node attributes themselves.
200  *
201  * XXX we may ultimately desire to simply remove the uid/gid/mode
202  * from the node entirely.
203  *
204  * MPSAFE - sorta.  Theoretically the overwrite can compete since they
205  *	    are loading from the same fields.
206  */
207 static __inline void
208 node_sync_dev_get(struct devfs_node *node)
209 {
210 	cdev_t dev;
211 
212 	if ((dev = node->d_dev) && (dev->si_flags & SI_OVERRIDE)) {
213 		node->uid = dev->si_uid;
214 		node->gid = dev->si_gid;
215 		node->mode = dev->si_perms;
216 	}
217 }
218 
219 static __inline void
220 node_sync_dev_set(struct devfs_node *node)
221 {
222 	cdev_t dev;
223 
224 	if ((dev = node->d_dev) && (dev->si_flags & SI_OVERRIDE)) {
225 		dev->si_uid = node->uid;
226 		dev->si_gid = node->gid;
227 		dev->si_perms = node->mode;
228 	}
229 }
230 
231 /*
232  * generic entry point for unsupported operations
233  */
234 static int
235 devfs_vop_badop(struct vop_generic_args *ap)
236 {
237 	return (EIO);
238 }
239 
240 
241 static int
242 devfs_vop_access(struct vop_access_args *ap)
243 {
244 	struct devfs_node *node = DEVFS_NODE(ap->a_vp);
245 	int error;
246 
247 	if (!devfs_node_is_accessible(node))
248 		return ENOENT;
249 	node_sync_dev_get(node);
250 	error = vop_helper_access(ap, node->uid, node->gid,
251 				  node->mode, node->flags);
252 
253 	return error;
254 }
255 
256 
257 static int
258 devfs_vop_inactive(struct vop_inactive_args *ap)
259 {
260 	struct devfs_node *node = DEVFS_NODE(ap->a_vp);
261 
262 	if (node == NULL || (node->flags & DEVFS_NODE_LINKED) == 0)
263 		vrecycle(ap->a_vp);
264 	return 0;
265 }
266 
267 
268 static int
269 devfs_vop_reclaim(struct vop_reclaim_args *ap)
270 {
271 	struct devfs_node *node;
272 	struct vnode *vp;
273 	int locked;
274 
275 	/*
276 	 * Check if it is locked already. if not, we acquire the devfs lock
277 	 */
278 	if (!(lockstatus(&devfs_lock, curthread)) == LK_EXCLUSIVE) {
279 		lockmgr(&devfs_lock, LK_EXCLUSIVE);
280 		locked = 1;
281 	} else {
282 		locked = 0;
283 	}
284 
285 	/*
286 	 * Get rid of the devfs_node if it is no longer linked into the
287 	 * topology.
288 	 */
289 	vp = ap->a_vp;
290 	if ((node = DEVFS_NODE(vp)) != NULL) {
291 		node->v_node = NULL;
292 		if ((node->flags & DEVFS_NODE_LINKED) == 0)
293 			devfs_freep(node);
294 	}
295 
296 	if (locked)
297 		lockmgr(&devfs_lock, LK_RELEASE);
298 
299 	/*
300 	 * v_rdev needs to be properly released using v_release_rdev
301 	 * Make sure v_data is NULL as well.
302 	 */
303 	vp->v_data = NULL;
304 	v_release_rdev(vp);
305 	return 0;
306 }
307 
308 
309 static int
310 devfs_vop_readdir(struct vop_readdir_args *ap)
311 {
312 	struct devfs_node *dnode = DEVFS_NODE(ap->a_vp);
313 	struct devfs_node *node;
314 	int cookie_index;
315 	int ncookies;
316 	int error2;
317 	int error;
318 	int r;
319 	off_t *cookies;
320 	off_t saveoff;
321 
322 	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_readdir() called!\n");
323 
324 	if (ap->a_uio->uio_offset < 0 || ap->a_uio->uio_offset > INT_MAX)
325 		return (EINVAL);
326 	if ((error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY)) != 0)
327 		return (error);
328 
329 	if (!devfs_node_is_accessible(dnode)) {
330 		vn_unlock(ap->a_vp);
331 		return ENOENT;
332 	}
333 
334 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
335 
336 	saveoff = ap->a_uio->uio_offset;
337 
338 	if (ap->a_ncookies) {
339 		ncookies = ap->a_uio->uio_resid / 16 + 1; /* Why / 16 ?? */
340 		if (ncookies > 256)
341 			ncookies = 256;
342 		cookies = kmalloc(256 * sizeof(off_t), M_TEMP, M_WAITOK);
343 		cookie_index = 0;
344 	} else {
345 		ncookies = -1;
346 		cookies = NULL;
347 		cookie_index = 0;
348 	}
349 
350 	nanotime(&dnode->atime);
351 
352 	if (saveoff == 0) {
353 		r = vop_write_dirent(&error, ap->a_uio, dnode->d_dir.d_ino,
354 				     DT_DIR, 1, ".");
355 		if (r)
356 			goto done;
357 		if (cookies)
358 			cookies[cookie_index] = saveoff;
359 		saveoff++;
360 		cookie_index++;
361 		if (cookie_index == ncookies)
362 			goto done;
363 	}
364 
365 	if (saveoff == 1) {
366 		if (dnode->parent) {
367 			r = vop_write_dirent(&error, ap->a_uio,
368 					     dnode->parent->d_dir.d_ino,
369 					     DT_DIR, 2, "..");
370 		} else {
371 			r = vop_write_dirent(&error, ap->a_uio,
372 					     dnode->d_dir.d_ino,
373 					     DT_DIR, 2, "..");
374 		}
375 		if (r)
376 			goto done;
377 		if (cookies)
378 			cookies[cookie_index] = saveoff;
379 		saveoff++;
380 		cookie_index++;
381 		if (cookie_index == ncookies)
382 			goto done;
383 	}
384 
385 	TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(dnode), link) {
386 		if ((node->flags & DEVFS_HIDDEN) ||
387 		    (node->flags & DEVFS_INVISIBLE)) {
388 			continue;
389 		}
390 
391 		/*
392 		 * If the node type is a valid devfs alias, then we make
393 		 * sure that the target isn't hidden. If it is, we don't
394 		 * show the link in the directory listing.
395 		 */
396 		if ((node->node_type == Nlink) && (node->link_target != NULL) &&
397 			(node->link_target->flags & DEVFS_HIDDEN))
398 			continue;
399 
400 		if (node->cookie < saveoff)
401 			continue;
402 
403 		saveoff = node->cookie;
404 
405 		error2 = vop_write_dirent(&error, ap->a_uio, node->d_dir.d_ino,
406 					  node->d_dir.d_type,
407 					  node->d_dir.d_namlen,
408 					  node->d_dir.d_name);
409 
410 		if (error2)
411 			break;
412 
413 		saveoff++;
414 
415 		if (cookies)
416 			cookies[cookie_index] = node->cookie;
417 		++cookie_index;
418 		if (cookie_index == ncookies)
419 			break;
420 	}
421 
422 done:
423 	lockmgr(&devfs_lock, LK_RELEASE);
424 	vn_unlock(ap->a_vp);
425 
426 	ap->a_uio->uio_offset = saveoff;
427 	if (error && cookie_index == 0) {
428 		if (cookies) {
429 			kfree(cookies, M_TEMP);
430 			*ap->a_ncookies = 0;
431 			*ap->a_cookies = NULL;
432 		}
433 	} else {
434 		if (cookies) {
435 			*ap->a_ncookies = cookie_index;
436 			*ap->a_cookies = cookies;
437 		}
438 	}
439 	return (error);
440 }
441 
442 
443 static int
444 devfs_vop_nresolve(struct vop_nresolve_args *ap)
445 {
446 	struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp);
447 	struct devfs_node *node, *found = NULL;
448 	struct namecache *ncp;
449 	struct vnode *vp = NULL;
450 	int error = 0;
451 	int len;
452 	int depth;
453 
454 	ncp = ap->a_nch->ncp;
455 	len = ncp->nc_nlen;
456 
457 	if (!devfs_node_is_accessible(dnode))
458 		return ENOENT;
459 
460 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
461 
462 	if ((dnode->node_type != Nroot) && (dnode->node_type != Ndir)) {
463 		error = ENOENT;
464 		cache_setvp(ap->a_nch, NULL);
465 		goto out;
466 	}
467 
468 	TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(dnode), link) {
469 		if (len == node->d_dir.d_namlen) {
470 			if (!memcmp(ncp->nc_name, node->d_dir.d_name, len)) {
471 				found = node;
472 				break;
473 			}
474 		}
475 	}
476 
477 	if (found) {
478 		depth = 0;
479 		while ((found->node_type == Nlink) && (found->link_target)) {
480 			if (depth >= 8) {
481 				devfs_debug(DEVFS_DEBUG_SHOW, "Recursive link or depth >= 8");
482 				break;
483 			}
484 
485 			found = found->link_target;
486 			++depth;
487 		}
488 
489 		if (!(found->flags & DEVFS_HIDDEN))
490 			devfs_allocv(/*ap->a_dvp->v_mount, */ &vp, found);
491 	}
492 
493 	if (vp == NULL) {
494 		error = ENOENT;
495 		cache_setvp(ap->a_nch, NULL);
496 		goto out;
497 
498 	}
499 	KKASSERT(vp);
500 	vn_unlock(vp);
501 	cache_setvp(ap->a_nch, vp);
502 	vrele(vp);
503 out:
504 	lockmgr(&devfs_lock, LK_RELEASE);
505 
506 	return error;
507 }
508 
509 
510 static int
511 devfs_vop_nlookupdotdot(struct vop_nlookupdotdot_args *ap)
512 {
513 	struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp);
514 
515 	*ap->a_vpp = NULL;
516 	if (!devfs_node_is_accessible(dnode))
517 		return ENOENT;
518 
519 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
520 	if (dnode->parent != NULL) {
521 		devfs_allocv(ap->a_vpp, dnode->parent);
522 		vn_unlock(*ap->a_vpp);
523 	}
524 	lockmgr(&devfs_lock, LK_RELEASE);
525 
526 	return ((*ap->a_vpp == NULL) ? ENOENT : 0);
527 }
528 
529 
530 static int
531 devfs_vop_getattr(struct vop_getattr_args *ap)
532 {
533 	struct devfs_node *node = DEVFS_NODE(ap->a_vp);
534 	struct vattr *vap = ap->a_vap;
535 	struct partinfo pinfo;
536 	int error = 0;
537 
538 #if 0
539 	if (!devfs_node_is_accessible(node))
540 		return ENOENT;
541 #endif
542 	node_sync_dev_get(node);
543 
544 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
545 
546 	/* start by zeroing out the attributes */
547 	VATTR_NULL(vap);
548 
549 	/* next do all the common fields */
550 	vap->va_type = ap->a_vp->v_type;
551 	vap->va_mode = node->mode;
552 	vap->va_fileid = DEVFS_NODE(ap->a_vp)->d_dir.d_ino ;
553 	vap->va_flags = 0;
554 	vap->va_blocksize = DEV_BSIZE;
555 	vap->va_bytes = vap->va_size = 0;
556 
557 	vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
558 
559 	vap->va_atime = node->atime;
560 	vap->va_mtime = node->mtime;
561 	vap->va_ctime = node->ctime;
562 
563 	vap->va_nlink = 1; /* number of references to file */
564 
565 	vap->va_uid = node->uid;
566 	vap->va_gid = node->gid;
567 
568 	vap->va_rmajor = 0;
569 	vap->va_rminor = 0;
570 
571 	if ((node->node_type == Ndev) && node->d_dev)  {
572 		reference_dev(node->d_dev);
573 		vap->va_rminor = node->d_dev->si_uminor;
574 		release_dev(node->d_dev);
575 	}
576 
577 	/* For a softlink the va_size is the length of the softlink */
578 	if (node->symlink_name != 0) {
579 		vap->va_bytes = vap->va_size = node->symlink_namelen;
580 	}
581 
582 	/*
583 	 * For a disk-type device, va_size is the size of the underlying
584 	 * device, so that lseek() works properly.
585 	 */
586 	if ((node->d_dev) && (dev_dflags(node->d_dev) & D_DISK)) {
587 		bzero(&pinfo, sizeof(pinfo));
588 		error = dev_dioctl(node->d_dev, DIOCGPART, (void *)&pinfo,
589 				   0, proc0.p_ucred, NULL);
590 		if ((error == 0) && (pinfo.media_blksize != 0)) {
591 			vap->va_size = pinfo.media_size;
592 		} else {
593 			vap->va_size = 0;
594 			error = 0;
595 		}
596 	}
597 
598 	lockmgr(&devfs_lock, LK_RELEASE);
599 
600 	return (error);
601 }
602 
603 
604 static int
605 devfs_vop_setattr(struct vop_setattr_args *ap)
606 {
607 	struct devfs_node *node = DEVFS_NODE(ap->a_vp);
608 	struct vattr *vap;
609 	uid_t cur_uid;
610 	gid_t cur_gid;
611 	mode_t cur_mode;
612 	int error = 0;
613 
614 	if (!devfs_node_is_accessible(node))
615 		return ENOENT;
616 	node_sync_dev_get(node);
617 
618 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
619 
620 	vap = ap->a_vap;
621 
622 	if ((vap->va_uid != (uid_t)VNOVAL) || (vap->va_gid != (gid_t)VNOVAL)) {
623 		cur_uid = node->uid;
624 		cur_gid = node->gid;
625 		cur_mode = node->mode;
626 		error = vop_helper_chown(ap->a_vp, vap->va_uid, vap->va_gid,
627 		    ap->a_cred, &cur_uid, &cur_gid, &cur_mode);
628 		if (error)
629 			goto out;
630 
631 		if (node->uid != cur_uid || node->gid != cur_gid) {
632 			node->uid = cur_uid;
633 			node->gid = cur_gid;
634 			node->mode = cur_mode;
635 		}
636 	}
637 
638 	if (vap->va_mode != (mode_t)VNOVAL) {
639 		cur_mode = node->mode;
640 		error = vop_helper_chmod(ap->a_vp, vap->va_mode, ap->a_cred,
641 		    node->uid, node->gid, &cur_mode);
642 		if (error == 0 && node->mode != cur_mode) {
643 			node->mode = cur_mode;
644 		}
645 	}
646 
647 out:
648 	node_sync_dev_set(node);
649 	nanotime(&node->ctime);
650 	lockmgr(&devfs_lock, LK_RELEASE);
651 
652 	return error;
653 }
654 
655 
656 static int
657 devfs_vop_readlink(struct vop_readlink_args *ap)
658 {
659 	struct devfs_node *node = DEVFS_NODE(ap->a_vp);
660 	int ret;
661 
662 	if (!devfs_node_is_accessible(node))
663 		return ENOENT;
664 
665 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
666 	ret = uiomove(node->symlink_name, node->symlink_namelen, ap->a_uio);
667 	lockmgr(&devfs_lock, LK_RELEASE);
668 
669 	return ret;
670 }
671 
672 
673 static int
674 devfs_vop_print(struct vop_print_args *ap)
675 {
676 	return (0);
677 }
678 
679 static int
680 devfs_vop_nmkdir(struct vop_nmkdir_args *ap)
681 {
682 	struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp);
683 	struct devfs_node *node;
684 
685 	if (!devfs_node_is_accessible(dnode))
686 		return ENOENT;
687 
688 	if ((dnode->node_type != Nroot) && (dnode->node_type != Ndir))
689 		goto out;
690 
691 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
692 	devfs_allocvp(ap->a_dvp->v_mount, ap->a_vpp, Ndir,
693 		      ap->a_nch->ncp->nc_name, dnode, NULL);
694 
695 	if (*ap->a_vpp) {
696 		node = DEVFS_NODE(*ap->a_vpp);
697 		node->flags |= DEVFS_USER_CREATED;
698 		cache_setunresolved(ap->a_nch);
699 		cache_setvp(ap->a_nch, *ap->a_vpp);
700 	}
701 	lockmgr(&devfs_lock, LK_RELEASE);
702 out:
703 	return ((*ap->a_vpp == NULL) ? ENOTDIR : 0);
704 }
705 
706 static int
707 devfs_vop_nsymlink(struct vop_nsymlink_args *ap)
708 {
709 	struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp);
710 	struct devfs_node *node;
711 	size_t targetlen;
712 
713 	if (!devfs_node_is_accessible(dnode))
714 		return ENOENT;
715 
716 	ap->a_vap->va_type = VLNK;
717 
718 	if ((dnode->node_type != Nroot) && (dnode->node_type != Ndir))
719 		goto out;
720 
721 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
722 	devfs_allocvp(ap->a_dvp->v_mount, ap->a_vpp, Nlink,
723 		      ap->a_nch->ncp->nc_name, dnode, NULL);
724 
725 	targetlen = strlen(ap->a_target);
726 	if (*ap->a_vpp) {
727 		node = DEVFS_NODE(*ap->a_vpp);
728 		node->flags |= DEVFS_USER_CREATED;
729 		node->symlink_namelen = targetlen;
730 		node->symlink_name = kmalloc(targetlen + 1, M_DEVFS, M_WAITOK);
731 		memcpy(node->symlink_name, ap->a_target, targetlen);
732 		node->symlink_name[targetlen] = '\0';
733 		cache_setunresolved(ap->a_nch);
734 		cache_setvp(ap->a_nch, *ap->a_vpp);
735 	}
736 	lockmgr(&devfs_lock, LK_RELEASE);
737 out:
738 	return ((*ap->a_vpp == NULL) ? ENOTDIR : 0);
739 }
740 
741 static int
742 devfs_vop_nrmdir(struct vop_nrmdir_args *ap)
743 {
744 	struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp);
745 	struct devfs_node *node;
746 	struct namecache *ncp;
747 	int error = ENOENT;
748 
749 	ncp = ap->a_nch->ncp;
750 
751 	if (!devfs_node_is_accessible(dnode))
752 		return ENOENT;
753 
754 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
755 
756 	if ((dnode->node_type != Nroot) && (dnode->node_type != Ndir))
757 		goto out;
758 
759 	TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(dnode), link) {
760 		if (ncp->nc_nlen != node->d_dir.d_namlen)
761 			continue;
762 		if (memcmp(ncp->nc_name, node->d_dir.d_name, ncp->nc_nlen))
763 			continue;
764 
765 		/*
766 		 * only allow removal of user created dirs
767 		 */
768 		if ((node->flags & DEVFS_USER_CREATED) == 0) {
769 			error = EPERM;
770 			goto out;
771 		} else if (node->node_type != Ndir) {
772 			error = ENOTDIR;
773 			goto out;
774 		} else if (node->nchildren > 2) {
775 			error = ENOTEMPTY;
776 			goto out;
777 		} else {
778 			if (node->v_node)
779 				cache_inval_vp(node->v_node, CINV_DESTROY);
780 			devfs_unlinkp(node);
781 			error = 0;
782 			break;
783 		}
784 	}
785 
786 	cache_unlink(ap->a_nch);
787 out:
788 	lockmgr(&devfs_lock, LK_RELEASE);
789 	return error;
790 }
791 
792 static int
793 devfs_vop_nremove(struct vop_nremove_args *ap)
794 {
795 	struct devfs_node *dnode = DEVFS_NODE(ap->a_dvp);
796 	struct devfs_node *node;
797 	struct namecache *ncp;
798 	int error = ENOENT;
799 
800 	ncp = ap->a_nch->ncp;
801 
802 	if (!devfs_node_is_accessible(dnode))
803 		return ENOENT;
804 
805 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
806 
807 	if ((dnode->node_type != Nroot) && (dnode->node_type != Ndir))
808 		goto out;
809 
810 	TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(dnode), link) {
811 		if (ncp->nc_nlen != node->d_dir.d_namlen)
812 			continue;
813 		if (memcmp(ncp->nc_name, node->d_dir.d_name, ncp->nc_nlen))
814 			continue;
815 
816 		/*
817 		 * only allow removal of user created stuff (e.g. symlinks)
818 		 */
819 		if ((node->flags & DEVFS_USER_CREATED) == 0) {
820 			error = EPERM;
821 			goto out;
822 		} else if (node->node_type == Ndir) {
823 			error = EISDIR;
824 			goto out;
825 		} else {
826 			if (node->v_node)
827 				cache_inval_vp(node->v_node, CINV_DESTROY);
828 			devfs_unlinkp(node);
829 			error = 0;
830 			break;
831 		}
832 	}
833 
834 	cache_unlink(ap->a_nch);
835 out:
836 	lockmgr(&devfs_lock, LK_RELEASE);
837 	return error;
838 }
839 
840 
841 static int
842 devfs_spec_open(struct vop_open_args *ap)
843 {
844 	struct vnode *vp = ap->a_vp;
845 	struct vnode *orig_vp = NULL;
846 	struct devfs_node *node = DEVFS_NODE(vp);
847 	struct devfs_node *newnode;
848 	cdev_t dev, ndev = NULL;
849 	int error = 0;
850 
851 	if (node) {
852 		if (node->d_dev == NULL)
853 			return ENXIO;
854 		if (!devfs_node_is_accessible(node))
855 			return ENOENT;
856 	}
857 
858 	if ((dev = vp->v_rdev) == NULL)
859 		return ENXIO;
860 
861 	if (node && ap->a_fp) {
862 		devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_spec_open: -1.1-\n");
863 		lockmgr(&devfs_lock, LK_EXCLUSIVE);
864 
865 		ndev = devfs_clone(dev, node->d_dir.d_name, node->d_dir.d_namlen,
866 						ap->a_mode, ap->a_cred);
867 		if (ndev != NULL) {
868 			newnode = devfs_create_device_node(
869 					DEVFS_MNTDATA(vp->v_mount)->root_node,
870 					ndev, NULL, NULL);
871 			/* XXX: possibly destroy device if this happens */
872 
873 			if (newnode != NULL) {
874 				dev = ndev;
875 				devfs_link_dev(dev);
876 
877 				devfs_debug(DEVFS_DEBUG_DEBUG,
878 						"parent here is: %s, node is: |%s|\n",
879 						((node->parent->node_type == Nroot) ?
880 						"ROOT!" : node->parent->d_dir.d_name),
881 						newnode->d_dir.d_name);
882 				devfs_debug(DEVFS_DEBUG_DEBUG,
883 						"test: %s\n",
884 						((struct devfs_node *)(TAILQ_LAST(DEVFS_DENODE_HEAD(node->parent), devfs_node_head)))->d_dir.d_name);
885 
886 				/*
887 				 * orig_vp is set to the original vp if we cloned.
888 				 */
889 				/* node->flags |= DEVFS_CLONED; */
890 				devfs_allocv(&vp, newnode);
891 				orig_vp = ap->a_vp;
892 				ap->a_vp = vp;
893 			}
894 		}
895 		lockmgr(&devfs_lock, LK_RELEASE);
896 	}
897 
898 	devfs_debug(DEVFS_DEBUG_DEBUG,
899 		    "devfs_spec_open() called on %s! \n",
900 		    dev->si_name);
901 
902 	/*
903 	 * Make this field valid before any I/O in ->d_open
904 	 */
905 	if (!dev->si_iosize_max)
906 		/* XXX: old DFLTPHYS == 64KB dependency */
907 		dev->si_iosize_max = min(MAXPHYS,64*1024);
908 
909 	if (dev_dflags(dev) & D_TTY)
910 		vsetflags(vp, VISTTY);
911 
912 	/*
913 	 * Open underlying device
914 	 */
915 	vn_unlock(vp);
916 	error = dev_dopen(dev, ap->a_mode, S_IFCHR, ap->a_cred);
917 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
918 
919 	/*
920 	 * Clean up any cloned vp if we error out.
921 	 */
922 	if (error) {
923 		if (orig_vp) {
924 			vput(vp);
925 			ap->a_vp = orig_vp;
926 			/* orig_vp = NULL; */
927 		}
928 		return error;
929 	}
930 
931 	/*
932 	 * This checks if the disk device is going to be opened for writing.
933 	 * It will be only allowed in the cases where securelevel permits it
934 	 * and it's not mounted R/W.
935 	 */
936 	if ((dev_dflags(dev) & D_DISK) && (ap->a_mode & FWRITE) &&
937 	    (ap->a_cred != FSCRED)) {
938 
939 		/* Very secure mode. No open for writing allowed */
940 		if (securelevel >= 2)
941 			return EPERM;
942 
943 		/*
944 		 * If it is mounted R/W, do not allow to open for writing.
945 		 * In the case it's mounted read-only but securelevel
946 		 * is >= 1, then do not allow opening for writing either.
947 		 */
948 		if (vfs_mountedon(vp)) {
949 			if (!(dev->si_mountpoint->mnt_flag & MNT_RDONLY))
950 				return EBUSY;
951 			else if (securelevel >= 1)
952 				return EPERM;
953 		}
954 	}
955 
956 	if (dev_dflags(dev) & D_TTY) {
957 		if (dev->si_tty) {
958 			struct tty *tp;
959 			tp = dev->si_tty;
960 			if (!tp->t_stop) {
961 				devfs_debug(DEVFS_DEBUG_DEBUG,
962 					    "devfs: no t_stop\n");
963 				tp->t_stop = nottystop;
964 			}
965 		}
966 	}
967 
968 
969 	if (vn_isdisk(vp, NULL)) {
970 		if (!dev->si_bsize_phys)
971 			dev->si_bsize_phys = DEV_BSIZE;
972 		vinitvmio(vp, IDX_TO_OFF(INT_MAX), PAGE_SIZE, -1);
973 	}
974 
975 	vop_stdopen(ap);
976 #if 0
977 	if (node)
978 		nanotime(&node->atime);
979 #endif
980 
981 	/*
982 	 * If we replaced the vp the vop_stdopen() call will have loaded
983 	 * it into fp->f_data and vref()d the vp, giving us two refs.  So
984 	 * instead of just unlocking it here we have to vput() it.
985 	 */
986 	if (orig_vp)
987 		vput(vp);
988 
989 	/* Ugly pty magic, to make pty devices appear once they are opened */
990 	if (node && (node->flags & DEVFS_PTY) == DEVFS_PTY)
991 		node->flags &= ~DEVFS_INVISIBLE;
992 
993 	if (ap->a_fp) {
994 		KKASSERT(ap->a_fp->f_type == DTYPE_VNODE);
995 		KKASSERT((ap->a_fp->f_flag & FMASK) == (ap->a_mode & FMASK));
996 		ap->a_fp->f_ops = &devfs_dev_fileops;
997 		KKASSERT(ap->a_fp->f_data == (void *)vp);
998 	}
999 
1000 	return 0;
1001 }
1002 
1003 
1004 static int
1005 devfs_spec_close(struct vop_close_args *ap)
1006 {
1007 	struct devfs_node *node;
1008 	struct proc *p = curproc;
1009 	struct vnode *vp = ap->a_vp;
1010 	cdev_t dev = vp->v_rdev;
1011 	int error = 0;
1012 	int needrelock;
1013 
1014 	if (dev)
1015 		devfs_debug(DEVFS_DEBUG_DEBUG,
1016 			    "devfs_spec_close() called on %s! \n",
1017 			    dev->si_name);
1018 	else
1019 		devfs_debug(DEVFS_DEBUG_DEBUG,
1020 			    "devfs_spec_close() called, null vode!\n");
1021 
1022 	/*
1023 	 * A couple of hacks for devices and tty devices.  The
1024 	 * vnode ref count cannot be used to figure out the
1025 	 * last close, but we can use v_opencount now that
1026 	 * revoke works properly.
1027 	 *
1028 	 * Detect the last close on a controlling terminal and clear
1029 	 * the session (half-close).
1030 	 */
1031 	if (dev)
1032 		reference_dev(dev);
1033 
1034 	if (p && vp->v_opencount <= 1 && vp == p->p_session->s_ttyvp) {
1035 		p->p_session->s_ttyvp = NULL;
1036 		vrele(vp);
1037 	}
1038 
1039 	/*
1040 	 * Vnodes can be opened and closed multiple times.  Do not really
1041 	 * close the device unless (1) it is being closed forcibly,
1042 	 * (2) the device wants to track closes, or (3) this is the last
1043 	 * vnode doing its last close on the device.
1044 	 *
1045 	 * XXX the VXLOCK (force close) case can leave vnodes referencing
1046 	 * a closed device.  This might not occur now that our revoke is
1047 	 * fixed.
1048 	 */
1049 	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_spec_close() -1- \n");
1050 	if (dev && ((vp->v_flag & VRECLAIMED) ||
1051 	    (dev_dflags(dev) & D_TRACKCLOSE) ||
1052 	    (vp->v_opencount == 1))) {
1053 		/*
1054 		 * Ugly pty magic, to make pty devices disappear again once
1055 		 * they are closed.
1056 		 */
1057 		node = DEVFS_NODE(ap->a_vp);
1058 		if (node && (node->flags & DEVFS_PTY))
1059 			node->flags |= DEVFS_INVISIBLE;
1060 
1061 		/*
1062 		 * Unlock around dev_dclose(), unless the vnode is
1063 		 * undergoing a vgone/reclaim (during umount).
1064 		 */
1065 		needrelock = 0;
1066 		if ((vp->v_flag & VRECLAIMED) == 0 && vn_islocked(vp)) {
1067 			needrelock = 1;
1068 			vn_unlock(vp);
1069 		}
1070 
1071 		/*
1072 		 * WARNING!  If the device destroys itself the devfs node
1073 		 *	     can disappear here.
1074 		 *
1075 		 * WARNING!  vn_lock() will fail if the vp is in a VRECLAIM,
1076 		 *	     which can occur during umount.
1077 		 */
1078 		error = dev_dclose(dev, ap->a_fflag, S_IFCHR);
1079 		/* node is now stale */
1080 
1081 		if (needrelock) {
1082 			if (vn_lock(vp, LK_EXCLUSIVE | LK_RETRY) != 0) {
1083 				panic("devfs_spec_close: vnode %p "
1084 				      "unexpectedly could not be relocked",
1085 				      vp);
1086 			}
1087 		}
1088 	} else {
1089 		error = 0;
1090 	}
1091 	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_spec_close() -2- \n");
1092 
1093 	/*
1094 	 * Track the actual opens and closes on the vnode.  The last close
1095 	 * disassociates the rdev.  If the rdev is already disassociated or
1096 	 * the opencount is already 0, the vnode might have been revoked
1097 	 * and no further opencount tracking occurs.
1098 	 */
1099 	if (dev)
1100 		release_dev(dev);
1101 	if (vp->v_opencount > 0)
1102 		vop_stdclose(ap);
1103 	return(error);
1104 
1105 }
1106 
1107 
1108 static int
1109 devfs_fo_close(struct file *fp)
1110 {
1111 	struct vnode *vp = (struct vnode *)fp->f_data;
1112 	int error;
1113 
1114 	fp->f_ops = &badfileops;
1115 	error = vn_close(vp, fp->f_flag);
1116 
1117 	return (error);
1118 }
1119 
1120 
1121 /*
1122  * Device-optimized file table vnode read routine.
1123  *
1124  * This bypasses the VOP table and talks directly to the device.  Most
1125  * filesystems just route to specfs and can make this optimization.
1126  *
1127  * MPALMOSTSAFE - acquires mplock
1128  */
1129 static int
1130 devfs_fo_read(struct file *fp, struct uio *uio,
1131 		 struct ucred *cred, int flags)
1132 {
1133 	struct devfs_node *node;
1134 	struct vnode *vp;
1135 	int ioflag;
1136 	int error;
1137 	cdev_t dev;
1138 
1139 	KASSERT(uio->uio_td == curthread,
1140 		("uio_td %p is not td %p", uio->uio_td, curthread));
1141 
1142 	if (uio->uio_resid == 0)
1143 		return 0;
1144 
1145 	vp = (struct vnode *)fp->f_data;
1146 	if (vp == NULL || vp->v_type == VBAD)
1147 		return EBADF;
1148 
1149 	node = DEVFS_NODE(vp);
1150 
1151 	if ((dev = vp->v_rdev) == NULL)
1152 		return EBADF;
1153 
1154 	reference_dev(dev);
1155 
1156 	if ((flags & O_FOFFSET) == 0)
1157 		uio->uio_offset = fp->f_offset;
1158 
1159 	ioflag = 0;
1160 	if (flags & O_FBLOCKING) {
1161 		/* ioflag &= ~IO_NDELAY; */
1162 	} else if (flags & O_FNONBLOCKING) {
1163 		ioflag |= IO_NDELAY;
1164 	} else if (fp->f_flag & FNONBLOCK) {
1165 		ioflag |= IO_NDELAY;
1166 	}
1167 	if (flags & O_FBUFFERED) {
1168 		/* ioflag &= ~IO_DIRECT; */
1169 	} else if (flags & O_FUNBUFFERED) {
1170 		ioflag |= IO_DIRECT;
1171 	} else if (fp->f_flag & O_DIRECT) {
1172 		ioflag |= IO_DIRECT;
1173 	}
1174 	ioflag |= sequential_heuristic(uio, fp);
1175 
1176 	error = dev_dread(dev, uio, ioflag);
1177 
1178 	release_dev(dev);
1179 	if (node)
1180 		nanotime(&node->atime);
1181 	if ((flags & O_FOFFSET) == 0)
1182 		fp->f_offset = uio->uio_offset;
1183 	fp->f_nextoff = uio->uio_offset;
1184 
1185 	return (error);
1186 }
1187 
1188 
1189 static int
1190 devfs_fo_write(struct file *fp, struct uio *uio,
1191 		  struct ucred *cred, int flags)
1192 {
1193 	struct devfs_node *node;
1194 	struct vnode *vp;
1195 	int ioflag;
1196 	int error;
1197 	cdev_t dev;
1198 
1199 	KASSERT(uio->uio_td == curthread,
1200 		("uio_td %p is not p %p", uio->uio_td, curthread));
1201 
1202 	vp = (struct vnode *)fp->f_data;
1203 	if (vp == NULL || vp->v_type == VBAD)
1204 		return EBADF;
1205 
1206 	node = DEVFS_NODE(vp);
1207 
1208 	if (vp->v_type == VREG)
1209 		bwillwrite(uio->uio_resid);
1210 
1211 	vp = (struct vnode *)fp->f_data;
1212 
1213 	if ((dev = vp->v_rdev) == NULL)
1214 		return EBADF;
1215 
1216 	reference_dev(dev);
1217 
1218 	if ((flags & O_FOFFSET) == 0)
1219 		uio->uio_offset = fp->f_offset;
1220 
1221 	ioflag = IO_UNIT;
1222 	if (vp->v_type == VREG &&
1223 	   ((fp->f_flag & O_APPEND) || (flags & O_FAPPEND))) {
1224 		ioflag |= IO_APPEND;
1225 	}
1226 
1227 	if (flags & O_FBLOCKING) {
1228 		/* ioflag &= ~IO_NDELAY; */
1229 	} else if (flags & O_FNONBLOCKING) {
1230 		ioflag |= IO_NDELAY;
1231 	} else if (fp->f_flag & FNONBLOCK) {
1232 		ioflag |= IO_NDELAY;
1233 	}
1234 	if (flags & O_FBUFFERED) {
1235 		/* ioflag &= ~IO_DIRECT; */
1236 	} else if (flags & O_FUNBUFFERED) {
1237 		ioflag |= IO_DIRECT;
1238 	} else if (fp->f_flag & O_DIRECT) {
1239 		ioflag |= IO_DIRECT;
1240 	}
1241 	if (flags & O_FASYNCWRITE) {
1242 		/* ioflag &= ~IO_SYNC; */
1243 	} else if (flags & O_FSYNCWRITE) {
1244 		ioflag |= IO_SYNC;
1245 	} else if (fp->f_flag & O_FSYNC) {
1246 		ioflag |= IO_SYNC;
1247 	}
1248 
1249 	if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))
1250 		ioflag |= IO_SYNC;
1251 	ioflag |= sequential_heuristic(uio, fp);
1252 
1253 	error = dev_dwrite(dev, uio, ioflag);
1254 
1255 	release_dev(dev);
1256 	if (node) {
1257 		nanotime(&node->atime);
1258 		nanotime(&node->mtime);
1259 	}
1260 
1261 	if ((flags & O_FOFFSET) == 0)
1262 		fp->f_offset = uio->uio_offset;
1263 	fp->f_nextoff = uio->uio_offset;
1264 
1265 	return (error);
1266 }
1267 
1268 
1269 static int
1270 devfs_fo_stat(struct file *fp, struct stat *sb, struct ucred *cred)
1271 {
1272 	struct vnode *vp;
1273 	struct vattr vattr;
1274 	struct vattr *vap;
1275 	u_short mode;
1276 	cdev_t dev;
1277 	int error;
1278 
1279 	vp = (struct vnode *)fp->f_data;
1280 	if (vp == NULL || vp->v_type == VBAD)
1281 		return EBADF;
1282 
1283 	error = vn_stat(vp, sb, cred);
1284 	if (error)
1285 		return (error);
1286 
1287 	vap = &vattr;
1288 	error = VOP_GETATTR(vp, vap);
1289 	if (error)
1290 		return (error);
1291 
1292 	/*
1293 	 * Zero the spare stat fields
1294 	 */
1295 	sb->st_lspare = 0;
1296 	sb->st_qspare1 = 0;
1297 	sb->st_qspare2 = 0;
1298 
1299 	/*
1300 	 * Copy from vattr table ... or not in case it's a cloned device
1301 	 */
1302 	if (vap->va_fsid != VNOVAL)
1303 		sb->st_dev = vap->va_fsid;
1304 	else
1305 		sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1306 
1307 	sb->st_ino = vap->va_fileid;
1308 
1309 	mode = vap->va_mode;
1310 	mode |= S_IFCHR;
1311 	sb->st_mode = mode;
1312 
1313 	if (vap->va_nlink > (nlink_t)-1)
1314 		sb->st_nlink = (nlink_t)-1;
1315 	else
1316 		sb->st_nlink = vap->va_nlink;
1317 
1318 	sb->st_uid = vap->va_uid;
1319 	sb->st_gid = vap->va_gid;
1320 	sb->st_rdev = dev2udev(DEVFS_NODE(vp)->d_dev);
1321 	sb->st_size = vap->va_bytes;
1322 	sb->st_atimespec = vap->va_atime;
1323 	sb->st_mtimespec = vap->va_mtime;
1324 	sb->st_ctimespec = vap->va_ctime;
1325 
1326 	/*
1327 	 * A VCHR and VBLK device may track the last access and last modified
1328 	 * time independantly of the filesystem.  This is particularly true
1329 	 * because device read and write calls may bypass the filesystem.
1330 	 */
1331 	if (vp->v_type == VCHR || vp->v_type == VBLK) {
1332 		dev = vp->v_rdev;
1333 		if (dev != NULL) {
1334 			if (dev->si_lastread) {
1335 				sb->st_atimespec.tv_sec = dev->si_lastread;
1336 				sb->st_atimespec.tv_nsec = 0;
1337 			}
1338 			if (dev->si_lastwrite) {
1339 				sb->st_atimespec.tv_sec = dev->si_lastwrite;
1340 				sb->st_atimespec.tv_nsec = 0;
1341 			}
1342 		}
1343 	}
1344 
1345         /*
1346 	 * According to www.opengroup.org, the meaning of st_blksize is
1347 	 *   "a filesystem-specific preferred I/O block size for this
1348 	 *    object.  In some filesystem types, this may vary from file
1349 	 *    to file"
1350 	 * Default to PAGE_SIZE after much discussion.
1351 	 */
1352 
1353 	sb->st_blksize = PAGE_SIZE;
1354 
1355 	sb->st_flags = vap->va_flags;
1356 
1357 	error = priv_check_cred(cred, PRIV_VFS_GENERATION, 0);
1358 	if (error)
1359 		sb->st_gen = 0;
1360 	else
1361 		sb->st_gen = (u_int32_t)vap->va_gen;
1362 
1363 	sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1364 
1365 	return (0);
1366 }
1367 
1368 
1369 static int
1370 devfs_fo_kqfilter(struct file *fp, struct knote *kn)
1371 {
1372 	struct vnode *vp;
1373 	int error;
1374 	cdev_t dev;
1375 
1376 	vp = (struct vnode *)fp->f_data;
1377 	if (vp == NULL || vp->v_type == VBAD) {
1378 		error = EBADF;
1379 		goto done;
1380 	}
1381 	if ((dev = vp->v_rdev) == NULL) {
1382 		error = EBADF;
1383 		goto done;
1384 	}
1385 	reference_dev(dev);
1386 
1387 	error = dev_dkqfilter(dev, kn);
1388 
1389 	release_dev(dev);
1390 
1391 done:
1392 	return (error);
1393 }
1394 
1395 /*
1396  * MPALMOSTSAFE - acquires mplock
1397  */
1398 static int
1399 devfs_fo_ioctl(struct file *fp, u_long com, caddr_t data,
1400 		  struct ucred *ucred, struct sysmsg *msg)
1401 {
1402 	struct devfs_node *node;
1403 	struct vnode *vp;
1404 	struct vnode *ovp;
1405 	cdev_t	dev;
1406 	int error;
1407 	struct fiodname_args *name_args;
1408 	size_t namlen;
1409 	const char *name;
1410 
1411 	vp = ((struct vnode *)fp->f_data);
1412 
1413 	if ((dev = vp->v_rdev) == NULL)
1414 		return EBADF;		/* device was revoked */
1415 
1416 	reference_dev(dev);
1417 
1418 	node = DEVFS_NODE(vp);
1419 
1420 	devfs_debug(DEVFS_DEBUG_DEBUG,
1421 		    "devfs_fo_ioctl() called! for dev %s\n",
1422 		    dev->si_name);
1423 
1424 	if (com == FIODTYPE) {
1425 		*(int *)data = dev_dflags(dev) & D_TYPEMASK;
1426 		error = 0;
1427 		goto out;
1428 	} else if (com == FIODNAME) {
1429 		name_args = (struct fiodname_args *)data;
1430 		name = dev->si_name;
1431 		namlen = strlen(name) + 1;
1432 
1433 		devfs_debug(DEVFS_DEBUG_DEBUG,
1434 			    "ioctl, got: FIODNAME for %s\n", name);
1435 
1436 		if (namlen <= name_args->len)
1437 			error = copyout(dev->si_name, name_args->name, namlen);
1438 		else
1439 			error = EINVAL;
1440 
1441 		devfs_debug(DEVFS_DEBUG_DEBUG,
1442 			    "ioctl stuff: error: %d\n", error);
1443 		goto out;
1444 	}
1445 
1446 	error = dev_dioctl(dev, com, data, fp->f_flag, ucred, msg);
1447 
1448 #if 0
1449 	if (node) {
1450 		nanotime(&node->atime);
1451 		nanotime(&node->mtime);
1452 	}
1453 #endif
1454 	if (com == TIOCSCTTY) {
1455 		devfs_debug(DEVFS_DEBUG_DEBUG,
1456 			    "devfs_fo_ioctl: got TIOCSCTTY on %s\n",
1457 			    dev->si_name);
1458 	}
1459 	if (error == 0 && com == TIOCSCTTY) {
1460 		struct proc *p = curthread->td_proc;
1461 		struct session *sess;
1462 
1463 		devfs_debug(DEVFS_DEBUG_DEBUG,
1464 			    "devfs_fo_ioctl: dealing with TIOCSCTTY on %s\n",
1465 			    dev->si_name);
1466 		if (p == NULL) {
1467 			error = ENOTTY;
1468 			goto out;
1469 		}
1470 		sess = p->p_session;
1471 
1472 		/*
1473 		 * Do nothing if reassigning same control tty
1474 		 */
1475 		if (sess->s_ttyvp == vp) {
1476 			error = 0;
1477 			goto out;
1478 		}
1479 
1480 		/*
1481 		 * Get rid of reference to old control tty
1482 		 */
1483 		ovp = sess->s_ttyvp;
1484 		vref(vp);
1485 		sess->s_ttyvp = vp;
1486 		if (ovp)
1487 			vrele(ovp);
1488 	}
1489 
1490 out:
1491 	release_dev(dev);
1492 	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_fo_ioctl() finished! \n");
1493 	return (error);
1494 }
1495 
1496 
1497 static int
1498 devfs_spec_fsync(struct vop_fsync_args *ap)
1499 {
1500 	struct vnode *vp = ap->a_vp;
1501 	int error;
1502 
1503 	if (!vn_isdisk(vp, NULL))
1504 		return (0);
1505 
1506 	/*
1507 	 * Flush all dirty buffers associated with a block device.
1508 	 */
1509 	error = vfsync(vp, ap->a_waitfor, 10000, NULL, NULL);
1510 	return (error);
1511 }
1512 
1513 static int
1514 devfs_spec_read(struct vop_read_args *ap)
1515 {
1516 	struct devfs_node *node;
1517 	struct vnode *vp;
1518 	struct uio *uio;
1519 	cdev_t dev;
1520 	int error;
1521 
1522 	vp = ap->a_vp;
1523 	dev = vp->v_rdev;
1524 	uio = ap->a_uio;
1525 	node = DEVFS_NODE(vp);
1526 
1527 	if (dev == NULL)		/* device was revoked */
1528 		return (EBADF);
1529 	if (uio->uio_resid == 0)
1530 		return (0);
1531 
1532 	vn_unlock(vp);
1533 	error = dev_dread(dev, uio, ap->a_ioflag);
1534 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1535 
1536 	if (node)
1537 		nanotime(&node->atime);
1538 
1539 	return (error);
1540 }
1541 
1542 /*
1543  * Vnode op for write
1544  *
1545  * spec_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
1546  *	      struct ucred *a_cred)
1547  */
1548 static int
1549 devfs_spec_write(struct vop_write_args *ap)
1550 {
1551 	struct devfs_node *node;
1552 	struct vnode *vp;
1553 	struct uio *uio;
1554 	cdev_t dev;
1555 	int error;
1556 
1557 	vp = ap->a_vp;
1558 	dev = vp->v_rdev;
1559 	uio = ap->a_uio;
1560 	node = DEVFS_NODE(vp);
1561 
1562 	KKASSERT(uio->uio_segflg != UIO_NOCOPY);
1563 
1564 	if (dev == NULL)		/* device was revoked */
1565 		return (EBADF);
1566 
1567 	vn_unlock(vp);
1568 	error = dev_dwrite(dev, uio, ap->a_ioflag);
1569 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1570 
1571 	if (node) {
1572 		nanotime(&node->atime);
1573 		nanotime(&node->mtime);
1574 	}
1575 
1576 	return (error);
1577 }
1578 
1579 /*
1580  * Device ioctl operation.
1581  *
1582  * spec_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data,
1583  *	      int a_fflag, struct ucred *a_cred, struct sysmsg *msg)
1584  */
1585 static int
1586 devfs_spec_ioctl(struct vop_ioctl_args *ap)
1587 {
1588 	struct vnode *vp = ap->a_vp;
1589 	struct devfs_node *node;
1590 	cdev_t dev;
1591 
1592 	if ((dev = vp->v_rdev) == NULL)
1593 		return (EBADF);		/* device was revoked */
1594 	node = DEVFS_NODE(vp);
1595 
1596 #if 0
1597 	if (node) {
1598 		nanotime(&node->atime);
1599 		nanotime(&node->mtime);
1600 	}
1601 #endif
1602 
1603 	return (dev_dioctl(dev, ap->a_command, ap->a_data, ap->a_fflag,
1604 			   ap->a_cred, ap->a_sysmsg));
1605 }
1606 
1607 /*
1608  * spec_kqfilter(struct vnode *a_vp, struct knote *a_kn)
1609  */
1610 /* ARGSUSED */
1611 static int
1612 devfs_spec_kqfilter(struct vop_kqfilter_args *ap)
1613 {
1614 	struct vnode *vp = ap->a_vp;
1615 	struct devfs_node *node;
1616 	cdev_t dev;
1617 
1618 	if ((dev = vp->v_rdev) == NULL)
1619 		return (EBADF);		/* device was revoked (EBADF) */
1620 	node = DEVFS_NODE(vp);
1621 
1622 #if 0
1623 	if (node)
1624 		nanotime(&node->atime);
1625 #endif
1626 
1627 	return (dev_dkqfilter(dev, ap->a_kn));
1628 }
1629 
1630 /*
1631  * Convert a vnode strategy call into a device strategy call.  Vnode strategy
1632  * calls are not limited to device DMA limits so we have to deal with the
1633  * case.
1634  *
1635  * spec_strategy(struct vnode *a_vp, struct bio *a_bio)
1636  */
1637 static int
1638 devfs_spec_strategy(struct vop_strategy_args *ap)
1639 {
1640 	struct bio *bio = ap->a_bio;
1641 	struct buf *bp = bio->bio_buf;
1642 	struct buf *nbp;
1643 	struct vnode *vp;
1644 	struct mount *mp;
1645 	int chunksize;
1646 	int maxiosize;
1647 
1648 	if (bp->b_cmd != BUF_CMD_READ && LIST_FIRST(&bp->b_dep) != NULL)
1649 		buf_start(bp);
1650 
1651 	/*
1652 	 * Collect statistics on synchronous and asynchronous read
1653 	 * and write counts for disks that have associated filesystems.
1654 	 */
1655 	vp = ap->a_vp;
1656 	KKASSERT(vp->v_rdev != NULL);	/* XXX */
1657 	if (vn_isdisk(vp, NULL) && (mp = vp->v_rdev->si_mountpoint) != NULL) {
1658 		if (bp->b_cmd == BUF_CMD_READ) {
1659 			if (bp->b_flags & BIO_SYNC)
1660 				mp->mnt_stat.f_syncreads++;
1661 			else
1662 				mp->mnt_stat.f_asyncreads++;
1663 		} else {
1664 			if (bp->b_flags & BIO_SYNC)
1665 				mp->mnt_stat.f_syncwrites++;
1666 			else
1667 				mp->mnt_stat.f_asyncwrites++;
1668 		}
1669 	}
1670 
1671         /*
1672          * Device iosize limitations only apply to read and write.  Shortcut
1673          * the I/O if it fits.
1674          */
1675 	if ((maxiosize = vp->v_rdev->si_iosize_max) == 0) {
1676 		devfs_debug(DEVFS_DEBUG_DEBUG,
1677 			    "%s: si_iosize_max not set!\n",
1678 			    dev_dname(vp->v_rdev));
1679 		maxiosize = MAXPHYS;
1680 	}
1681 #if SPEC_CHAIN_DEBUG & 2
1682 	maxiosize = 4096;
1683 #endif
1684         if (bp->b_bcount <= maxiosize ||
1685             (bp->b_cmd != BUF_CMD_READ && bp->b_cmd != BUF_CMD_WRITE)) {
1686                 dev_dstrategy_chain(vp->v_rdev, bio);
1687                 return (0);
1688         }
1689 
1690 	/*
1691 	 * Clone the buffer and set up an I/O chain to chunk up the I/O.
1692 	 */
1693 	nbp = kmalloc(sizeof(*bp), M_DEVBUF, M_INTWAIT|M_ZERO);
1694 	initbufbio(nbp);
1695 	buf_dep_init(nbp);
1696 	BUF_LOCK(nbp, LK_EXCLUSIVE);
1697 	BUF_KERNPROC(nbp);
1698 	nbp->b_vp = vp;
1699 	nbp->b_flags = B_PAGING | (bp->b_flags & B_BNOCLIP);
1700 	nbp->b_data = bp->b_data;
1701 	nbp->b_bio1.bio_done = devfs_spec_strategy_done;
1702 	nbp->b_bio1.bio_offset = bio->bio_offset;
1703 	nbp->b_bio1.bio_caller_info1.ptr = bio;
1704 
1705 	/*
1706 	 * Start the first transfer
1707 	 */
1708 	if (vn_isdisk(vp, NULL))
1709 		chunksize = vp->v_rdev->si_bsize_phys;
1710 	else
1711 		chunksize = DEV_BSIZE;
1712 	chunksize = maxiosize / chunksize * chunksize;
1713 #if SPEC_CHAIN_DEBUG & 1
1714 	devfs_debug(DEVFS_DEBUG_DEBUG,
1715 		    "spec_strategy chained I/O chunksize=%d\n",
1716 		    chunksize);
1717 #endif
1718 	nbp->b_cmd = bp->b_cmd;
1719 	nbp->b_bcount = chunksize;
1720 	nbp->b_bufsize = chunksize;	/* used to detect a short I/O */
1721 	nbp->b_bio1.bio_caller_info2.index = chunksize;
1722 
1723 #if SPEC_CHAIN_DEBUG & 1
1724 	devfs_debug(DEVFS_DEBUG_DEBUG,
1725 		    "spec_strategy: chain %p offset %d/%d bcount %d\n",
1726 		    bp, 0, bp->b_bcount, nbp->b_bcount);
1727 #endif
1728 
1729 	dev_dstrategy(vp->v_rdev, &nbp->b_bio1);
1730 
1731 	if (DEVFS_NODE(vp)) {
1732 		nanotime(&DEVFS_NODE(vp)->atime);
1733 		nanotime(&DEVFS_NODE(vp)->mtime);
1734 	}
1735 
1736 	return (0);
1737 }
1738 
1739 /*
1740  * Chunked up transfer completion routine - chain transfers until done
1741  *
1742  * NOTE: MPSAFE callback.
1743  */
1744 static
1745 void
1746 devfs_spec_strategy_done(struct bio *nbio)
1747 {
1748 	struct buf *nbp = nbio->bio_buf;
1749 	struct bio *bio = nbio->bio_caller_info1.ptr;	/* original bio */
1750 	struct buf *bp = bio->bio_buf;			/* original bp */
1751 	int chunksize = nbio->bio_caller_info2.index;	/* chunking */
1752 	int boffset = nbp->b_data - bp->b_data;
1753 
1754 	if (nbp->b_flags & B_ERROR) {
1755 		/*
1756 		 * An error terminates the chain, propogate the error back
1757 		 * to the original bp
1758 		 */
1759 		bp->b_flags |= B_ERROR;
1760 		bp->b_error = nbp->b_error;
1761 		bp->b_resid = bp->b_bcount - boffset +
1762 			      (nbp->b_bcount - nbp->b_resid);
1763 #if SPEC_CHAIN_DEBUG & 1
1764 		devfs_debug(DEVFS_DEBUG_DEBUG,
1765 			    "spec_strategy: chain %p error %d bcount %d/%d\n",
1766 			    bp, bp->b_error, bp->b_bcount,
1767 			    bp->b_bcount - bp->b_resid);
1768 #endif
1769 	} else if (nbp->b_resid) {
1770 		/*
1771 		 * A short read or write terminates the chain
1772 		 */
1773 		bp->b_error = nbp->b_error;
1774 		bp->b_resid = bp->b_bcount - boffset +
1775 			      (nbp->b_bcount - nbp->b_resid);
1776 #if SPEC_CHAIN_DEBUG & 1
1777 		devfs_debug(DEVFS_DEBUG_DEBUG,
1778 			    "spec_strategy: chain %p short read(1) "
1779 			    "bcount %d/%d\n",
1780 			    bp, bp->b_bcount - bp->b_resid, bp->b_bcount);
1781 #endif
1782 	} else if (nbp->b_bcount != nbp->b_bufsize) {
1783 		/*
1784 		 * A short read or write can also occur by truncating b_bcount
1785 		 */
1786 #if SPEC_CHAIN_DEBUG & 1
1787 		devfs_debug(DEVFS_DEBUG_DEBUG,
1788 			    "spec_strategy: chain %p short read(2) "
1789 			    "bcount %d/%d\n",
1790 			    bp, nbp->b_bcount + boffset, bp->b_bcount);
1791 #endif
1792 		bp->b_error = 0;
1793 		bp->b_bcount = nbp->b_bcount + boffset;
1794 		bp->b_resid = nbp->b_resid;
1795 	} else if (nbp->b_bcount + boffset == bp->b_bcount) {
1796 		/*
1797 		 * No more data terminates the chain
1798 		 */
1799 #if SPEC_CHAIN_DEBUG & 1
1800 		devfs_debug(DEVFS_DEBUG_DEBUG,
1801 			    "spec_strategy: chain %p finished bcount %d\n",
1802 			    bp, bp->b_bcount);
1803 #endif
1804 		bp->b_error = 0;
1805 		bp->b_resid = 0;
1806 	} else {
1807 		/*
1808 		 * Continue the chain
1809 		 */
1810 		boffset += nbp->b_bcount;
1811 		nbp->b_data = bp->b_data + boffset;
1812 		nbp->b_bcount = bp->b_bcount - boffset;
1813 		if (nbp->b_bcount > chunksize)
1814 			nbp->b_bcount = chunksize;
1815 		nbp->b_bio1.bio_done = devfs_spec_strategy_done;
1816 		nbp->b_bio1.bio_offset = bio->bio_offset + boffset;
1817 
1818 #if SPEC_CHAIN_DEBUG & 1
1819 		devfs_debug(DEVFS_DEBUG_DEBUG,
1820 			    "spec_strategy: chain %p offset %d/%d bcount %d\n",
1821 			    bp, boffset, bp->b_bcount, nbp->b_bcount);
1822 #endif
1823 
1824 		dev_dstrategy(nbp->b_vp->v_rdev, &nbp->b_bio1);
1825 		return;
1826 	}
1827 
1828 	/*
1829 	 * Fall through to here on termination.  biodone(bp) and
1830 	 * clean up and free nbp.
1831 	 */
1832 	biodone(bio);
1833 	BUF_UNLOCK(nbp);
1834 	uninitbufbio(nbp);
1835 	kfree(nbp, M_DEVBUF);
1836 }
1837 
1838 /*
1839  * spec_freeblks(struct vnode *a_vp, daddr_t a_addr, daddr_t a_length)
1840  */
1841 static int
1842 devfs_spec_freeblks(struct vop_freeblks_args *ap)
1843 {
1844 	struct buf *bp;
1845 
1846 	/*
1847 	 * XXX: This assumes that strategy does the deed right away.
1848 	 * XXX: this may not be TRTTD.
1849 	 */
1850 	KKASSERT(ap->a_vp->v_rdev != NULL);
1851 	if ((ap->a_vp->v_rdev->si_flags & SI_CANFREE) == 0)
1852 		return (0);
1853 	bp = geteblk(ap->a_length);
1854 	bp->b_cmd = BUF_CMD_FREEBLKS;
1855 	bp->b_bio1.bio_offset = ap->a_offset;
1856 	bp->b_bcount = ap->a_length;
1857 	dev_dstrategy(ap->a_vp->v_rdev, &bp->b_bio1);
1858 	return (0);
1859 }
1860 
1861 /*
1862  * Implement degenerate case where the block requested is the block
1863  * returned, and assume that the entire device is contiguous in regards
1864  * to the contiguous block range (runp and runb).
1865  *
1866  * spec_bmap(struct vnode *a_vp, off_t a_loffset,
1867  *	     off_t *a_doffsetp, int *a_runp, int *a_runb)
1868  */
1869 static int
1870 devfs_spec_bmap(struct vop_bmap_args *ap)
1871 {
1872 	if (ap->a_doffsetp != NULL)
1873 		*ap->a_doffsetp = ap->a_loffset;
1874 	if (ap->a_runp != NULL)
1875 		*ap->a_runp = MAXBSIZE;
1876 	if (ap->a_runb != NULL) {
1877 		if (ap->a_loffset < MAXBSIZE)
1878 			*ap->a_runb = (int)ap->a_loffset;
1879 		else
1880 			*ap->a_runb = MAXBSIZE;
1881 	}
1882 	return (0);
1883 }
1884 
1885 
1886 /*
1887  * Special device advisory byte-level locks.
1888  *
1889  * spec_advlock(struct vnode *a_vp, caddr_t a_id, int a_op,
1890  *		struct flock *a_fl, int a_flags)
1891  */
1892 /* ARGSUSED */
1893 static int
1894 devfs_spec_advlock(struct vop_advlock_args *ap)
1895 {
1896 	return ((ap->a_flags & F_POSIX) ? EINVAL : EOPNOTSUPP);
1897 }
1898 
1899 /*
1900  * NOTE: MPSAFE callback.
1901  */
1902 static void
1903 devfs_spec_getpages_iodone(struct bio *bio)
1904 {
1905 	bio->bio_buf->b_cmd = BUF_CMD_DONE;
1906 	wakeup(bio->bio_buf);
1907 }
1908 
1909 /*
1910  * spec_getpages() - get pages associated with device vnode.
1911  *
1912  * Note that spec_read and spec_write do not use the buffer cache, so we
1913  * must fully implement getpages here.
1914  */
1915 static int
1916 devfs_spec_getpages(struct vop_getpages_args *ap)
1917 {
1918 	vm_offset_t kva;
1919 	int error;
1920 	int i, pcount, size;
1921 	struct buf *bp;
1922 	vm_page_t m;
1923 	vm_ooffset_t offset;
1924 	int toff, nextoff, nread;
1925 	struct vnode *vp = ap->a_vp;
1926 	int blksiz;
1927 	int gotreqpage;
1928 
1929 	error = 0;
1930 	pcount = round_page(ap->a_count) / PAGE_SIZE;
1931 
1932 	/*
1933 	 * Calculate the offset of the transfer and do sanity check.
1934 	 */
1935 	offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset;
1936 
1937 	/*
1938 	 * Round up physical size for real devices.  We cannot round using
1939 	 * v_mount's block size data because v_mount has nothing to do with
1940 	 * the device.  i.e. it's usually '/dev'.  We need the physical block
1941 	 * size for the device itself.
1942 	 *
1943 	 * We can't use v_rdev->si_mountpoint because it only exists when the
1944 	 * block device is mounted.  However, we can use v_rdev.
1945 	 */
1946 	if (vn_isdisk(vp, NULL))
1947 		blksiz = vp->v_rdev->si_bsize_phys;
1948 	else
1949 		blksiz = DEV_BSIZE;
1950 
1951 	size = (ap->a_count + blksiz - 1) & ~(blksiz - 1);
1952 
1953 	bp = getpbuf_kva(NULL);
1954 	kva = (vm_offset_t)bp->b_data;
1955 
1956 	/*
1957 	 * Map the pages to be read into the kva.
1958 	 */
1959 	pmap_qenter(kva, ap->a_m, pcount);
1960 
1961 	/* Build a minimal buffer header. */
1962 	bp->b_cmd = BUF_CMD_READ;
1963 	bp->b_bcount = size;
1964 	bp->b_resid = 0;
1965 	bsetrunningbufspace(bp, size);
1966 
1967 	bp->b_bio1.bio_offset = offset;
1968 	bp->b_bio1.bio_done = devfs_spec_getpages_iodone;
1969 
1970 	mycpu->gd_cnt.v_vnodein++;
1971 	mycpu->gd_cnt.v_vnodepgsin += pcount;
1972 
1973 	/* Do the input. */
1974 	vn_strategy(ap->a_vp, &bp->b_bio1);
1975 
1976 	crit_enter();
1977 
1978 	/* We definitely need to be at splbio here. */
1979 	while (bp->b_cmd != BUF_CMD_DONE)
1980 		tsleep(bp, 0, "spread", 0);
1981 
1982 	crit_exit();
1983 
1984 	if (bp->b_flags & B_ERROR) {
1985 		if (bp->b_error)
1986 			error = bp->b_error;
1987 		else
1988 			error = EIO;
1989 	}
1990 
1991 	/*
1992 	 * If EOF is encountered we must zero-extend the result in order
1993 	 * to ensure that the page does not contain garabge.  When no
1994 	 * error occurs, an early EOF is indicated if b_bcount got truncated.
1995 	 * b_resid is relative to b_bcount and should be 0, but some devices
1996 	 * might indicate an EOF with b_resid instead of truncating b_bcount.
1997 	 */
1998 	nread = bp->b_bcount - bp->b_resid;
1999 	if (nread < ap->a_count)
2000 		bzero((caddr_t)kva + nread, ap->a_count - nread);
2001 	pmap_qremove(kva, pcount);
2002 
2003 	gotreqpage = 0;
2004 	for (i = 0, toff = 0; i < pcount; i++, toff = nextoff) {
2005 		nextoff = toff + PAGE_SIZE;
2006 		m = ap->a_m[i];
2007 
2008 		m->flags &= ~PG_ZERO;
2009 
2010 		/*
2011 		 * NOTE: vm_page_undirty/clear_dirty etc do not clear the
2012 		 *	 pmap modified bit.  pmap modified bit should have
2013 		 *	 already been cleared.
2014 		 */
2015 		if (nextoff <= nread) {
2016 			m->valid = VM_PAGE_BITS_ALL;
2017 			vm_page_undirty(m);
2018 		} else if (toff < nread) {
2019 			/*
2020 			 * Since this is a VM request, we have to supply the
2021 			 * unaligned offset to allow vm_page_set_valid()
2022 			 * to zero sub-DEV_BSIZE'd portions of the page.
2023 			 */
2024 			vm_page_set_valid(m, 0, nread - toff);
2025 			vm_page_clear_dirty_end_nonincl(m, 0, nread - toff);
2026 		} else {
2027 			m->valid = 0;
2028 			vm_page_undirty(m);
2029 		}
2030 
2031 		if (i != ap->a_reqpage) {
2032 			/*
2033 			 * Just in case someone was asking for this page we
2034 			 * now tell them that it is ok to use.
2035 			 */
2036 			if (!error || (m->valid == VM_PAGE_BITS_ALL)) {
2037 				if (m->valid) {
2038 					if (m->flags & PG_REFERENCED) {
2039 						vm_page_activate(m);
2040 					} else {
2041 						vm_page_deactivate(m);
2042 					}
2043 					vm_page_wakeup(m);
2044 				} else {
2045 					vm_page_free(m);
2046 				}
2047 			} else {
2048 				vm_page_free(m);
2049 			}
2050 		} else if (m->valid) {
2051 			gotreqpage = 1;
2052 			/*
2053 			 * Since this is a VM request, we need to make the
2054 			 * entire page presentable by zeroing invalid sections.
2055 			 */
2056 			if (m->valid != VM_PAGE_BITS_ALL)
2057 			    vm_page_zero_invalid(m, FALSE);
2058 		}
2059 	}
2060 	if (!gotreqpage) {
2061 		m = ap->a_m[ap->a_reqpage];
2062 		devfs_debug(DEVFS_DEBUG_WARNING,
2063 	    "spec_getpages:(%s) I/O read failure: (error=%d) bp %p vp %p\n",
2064 			devtoname(vp->v_rdev), error, bp, bp->b_vp);
2065 		devfs_debug(DEVFS_DEBUG_WARNING,
2066 	    "               size: %d, resid: %d, a_count: %d, valid: 0x%x\n",
2067 		    size, bp->b_resid, ap->a_count, m->valid);
2068 		devfs_debug(DEVFS_DEBUG_WARNING,
2069 	    "               nread: %d, reqpage: %d, pindex: %lu, pcount: %d\n",
2070 		    nread, ap->a_reqpage, (u_long)m->pindex, pcount);
2071 		/*
2072 		 * Free the buffer header back to the swap buffer pool.
2073 		 */
2074 		relpbuf(bp, NULL);
2075 		return VM_PAGER_ERROR;
2076 	}
2077 	/*
2078 	 * Free the buffer header back to the swap buffer pool.
2079 	 */
2080 	relpbuf(bp, NULL);
2081 	if (DEVFS_NODE(ap->a_vp))
2082 		nanotime(&DEVFS_NODE(ap->a_vp)->mtime);
2083 	return VM_PAGER_OK;
2084 }
2085 
2086 static __inline
2087 int
2088 sequential_heuristic(struct uio *uio, struct file *fp)
2089 {
2090 	/*
2091 	 * Sequential heuristic - detect sequential operation
2092 	 */
2093 	if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
2094 	    uio->uio_offset == fp->f_nextoff) {
2095 		/*
2096 		 * XXX we assume that the filesystem block size is
2097 		 * the default.  Not true, but still gives us a pretty
2098 		 * good indicator of how sequential the read operations
2099 		 * are.
2100 		 */
2101 		int tmpseq = fp->f_seqcount;
2102 
2103 		tmpseq += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE;
2104 		if (tmpseq > IO_SEQMAX)
2105 			tmpseq = IO_SEQMAX;
2106 		fp->f_seqcount = tmpseq;
2107 		return(fp->f_seqcount << IO_SEQSHIFT);
2108 	}
2109 
2110 	/*
2111 	 * Not sequential, quick draw-down of seqcount
2112 	 */
2113 	if (fp->f_seqcount > 1)
2114 		fp->f_seqcount = 1;
2115 	else
2116 		fp->f_seqcount = 0;
2117 	return(0);
2118 }
2119