xref: /dragonfly/sys/vfs/hammer/hammer_vnops.c (revision 2983445f)
1 /*
2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
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  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/vfs/hammer/hammer_vnops.c,v 1.102 2008/10/16 17:24:16 dillon Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/fcntl.h>
41 #include <sys/namecache.h>
42 #include <sys/vnode.h>
43 #include <sys/lockf.h>
44 #include <sys/event.h>
45 #include <sys/stat.h>
46 #include <sys/dirent.h>
47 #include <sys/file.h>
48 #include <vm/vm_extern.h>
49 #include <vfs/fifofs/fifo.h>
50 
51 #include <sys/mplock2.h>
52 
53 #include "hammer.h"
54 
55 /*
56  * USERFS VNOPS
57  */
58 /*static int hammer_vop_vnoperate(struct vop_generic_args *);*/
59 static int hammer_vop_fsync(struct vop_fsync_args *);
60 static int hammer_vop_read(struct vop_read_args *);
61 static int hammer_vop_write(struct vop_write_args *);
62 static int hammer_vop_access(struct vop_access_args *);
63 static int hammer_vop_advlock(struct vop_advlock_args *);
64 static int hammer_vop_close(struct vop_close_args *);
65 static int hammer_vop_ncreate(struct vop_ncreate_args *);
66 static int hammer_vop_getattr(struct vop_getattr_args *);
67 static int hammer_vop_nresolve(struct vop_nresolve_args *);
68 static int hammer_vop_nlookupdotdot(struct vop_nlookupdotdot_args *);
69 static int hammer_vop_nlink(struct vop_nlink_args *);
70 static int hammer_vop_nmkdir(struct vop_nmkdir_args *);
71 static int hammer_vop_nmknod(struct vop_nmknod_args *);
72 static int hammer_vop_open(struct vop_open_args *);
73 static int hammer_vop_print(struct vop_print_args *);
74 static int hammer_vop_readdir(struct vop_readdir_args *);
75 static int hammer_vop_readlink(struct vop_readlink_args *);
76 static int hammer_vop_nremove(struct vop_nremove_args *);
77 static int hammer_vop_nrename(struct vop_nrename_args *);
78 static int hammer_vop_nrmdir(struct vop_nrmdir_args *);
79 static int hammer_vop_markatime(struct vop_markatime_args *);
80 static int hammer_vop_setattr(struct vop_setattr_args *);
81 static int hammer_vop_strategy(struct vop_strategy_args *);
82 static int hammer_vop_bmap(struct vop_bmap_args *ap);
83 static int hammer_vop_nsymlink(struct vop_nsymlink_args *);
84 static int hammer_vop_nwhiteout(struct vop_nwhiteout_args *);
85 static int hammer_vop_ioctl(struct vop_ioctl_args *);
86 static int hammer_vop_mountctl(struct vop_mountctl_args *);
87 static int hammer_vop_kqfilter (struct vop_kqfilter_args *);
88 
89 static int hammer_vop_fifoclose (struct vop_close_args *);
90 static int hammer_vop_fiforead (struct vop_read_args *);
91 static int hammer_vop_fifowrite (struct vop_write_args *);
92 static int hammer_vop_fifokqfilter (struct vop_kqfilter_args *);
93 
94 struct vop_ops hammer_vnode_vops = {
95 	.vop_default =		vop_defaultop,
96 	.vop_fsync =		hammer_vop_fsync,
97 	.vop_getpages =		vop_stdgetpages,
98 	.vop_putpages =		vop_stdputpages,
99 	.vop_read =		hammer_vop_read,
100 	.vop_write =		hammer_vop_write,
101 	.vop_access =		hammer_vop_access,
102 	.vop_advlock =		hammer_vop_advlock,
103 	.vop_close =		hammer_vop_close,
104 	.vop_ncreate =		hammer_vop_ncreate,
105 	.vop_getattr =		hammer_vop_getattr,
106 	.vop_inactive =		hammer_vop_inactive,
107 	.vop_reclaim =		hammer_vop_reclaim,
108 	.vop_nresolve =		hammer_vop_nresolve,
109 	.vop_nlookupdotdot =	hammer_vop_nlookupdotdot,
110 	.vop_nlink =		hammer_vop_nlink,
111 	.vop_nmkdir =		hammer_vop_nmkdir,
112 	.vop_nmknod =		hammer_vop_nmknod,
113 	.vop_open =		hammer_vop_open,
114 	.vop_pathconf =		vop_stdpathconf,
115 	.vop_print =		hammer_vop_print,
116 	.vop_readdir =		hammer_vop_readdir,
117 	.vop_readlink =		hammer_vop_readlink,
118 	.vop_nremove =		hammer_vop_nremove,
119 	.vop_nrename =		hammer_vop_nrename,
120 	.vop_nrmdir =		hammer_vop_nrmdir,
121 	.vop_markatime = 	hammer_vop_markatime,
122 	.vop_setattr =		hammer_vop_setattr,
123 	.vop_bmap =		hammer_vop_bmap,
124 	.vop_strategy =		hammer_vop_strategy,
125 	.vop_nsymlink =		hammer_vop_nsymlink,
126 	.vop_nwhiteout =	hammer_vop_nwhiteout,
127 	.vop_ioctl =		hammer_vop_ioctl,
128 	.vop_mountctl =		hammer_vop_mountctl,
129 	.vop_kqfilter =		hammer_vop_kqfilter
130 };
131 
132 struct vop_ops hammer_spec_vops = {
133 	.vop_default =		vop_defaultop,
134 	.vop_fsync =		hammer_vop_fsync,
135 	.vop_read =		vop_stdnoread,
136 	.vop_write =		vop_stdnowrite,
137 	.vop_access =		hammer_vop_access,
138 	.vop_close =		hammer_vop_close,
139 	.vop_markatime = 	hammer_vop_markatime,
140 	.vop_getattr =		hammer_vop_getattr,
141 	.vop_inactive =		hammer_vop_inactive,
142 	.vop_reclaim =		hammer_vop_reclaim,
143 	.vop_setattr =		hammer_vop_setattr
144 };
145 
146 struct vop_ops hammer_fifo_vops = {
147 	.vop_default =		fifo_vnoperate,
148 	.vop_fsync =		hammer_vop_fsync,
149 	.vop_read =		hammer_vop_fiforead,
150 	.vop_write =		hammer_vop_fifowrite,
151 	.vop_access =		hammer_vop_access,
152 	.vop_close =		hammer_vop_fifoclose,
153 	.vop_markatime = 	hammer_vop_markatime,
154 	.vop_getattr =		hammer_vop_getattr,
155 	.vop_inactive =		hammer_vop_inactive,
156 	.vop_reclaim =		hammer_vop_reclaim,
157 	.vop_setattr =		hammer_vop_setattr,
158 	.vop_kqfilter =		hammer_vop_fifokqfilter
159 };
160 
161 static __inline
162 void
163 hammer_knote(struct vnode *vp, int flags)
164 {
165 	if (flags)
166 		KNOTE(&vp->v_pollinfo.vpi_kqinfo.ki_note, flags);
167 }
168 
169 #ifdef DEBUG_TRUNCATE
170 struct hammer_inode *HammerTruncIp;
171 #endif
172 
173 static int hammer_dounlink(hammer_transaction_t trans, struct nchandle *nch,
174 			   struct vnode *dvp, struct ucred *cred,
175 			   int flags, int isdir);
176 static int hammer_vop_strategy_read(struct vop_strategy_args *ap);
177 static int hammer_vop_strategy_write(struct vop_strategy_args *ap);
178 
179 #if 0
180 static
181 int
182 hammer_vop_vnoperate(struct vop_generic_args *)
183 {
184 	return (VOCALL(&hammer_vnode_vops, ap));
185 }
186 #endif
187 
188 /*
189  * hammer_vop_fsync { vp, waitfor }
190  *
191  * fsync() an inode to disk and wait for it to be completely committed
192  * such that the information would not be undone if a crash occured after
193  * return.
194  *
195  * NOTE: HAMMER's fsync()'s are going to remain expensive until we implement
196  *	 a REDO log.  A sysctl is provided to relax HAMMER's fsync()
197  *	 operation.
198  *
199  *	 Ultimately the combination of a REDO log and use of fast storage
200  *	 to front-end cluster caches will make fsync fast, but it aint
201  *	 here yet.  And, in anycase, we need real transactional
202  *	 all-or-nothing features which are not restricted to a single file.
203  */
204 static
205 int
206 hammer_vop_fsync(struct vop_fsync_args *ap)
207 {
208 	hammer_inode_t ip = VTOI(ap->a_vp);
209 	hammer_mount_t hmp = ip->hmp;
210 	int waitfor = ap->a_waitfor;
211 	int mode;
212 
213 	lwkt_gettoken(&hmp->fs_token);
214 
215 	/*
216 	 * Fsync rule relaxation (default is either full synchronous flush
217 	 * or REDO semantics with synchronous flush).
218 	 */
219 	if (ap->a_flags & VOP_FSYNC_SYSCALL) {
220 		switch(hammer_fsync_mode) {
221 		case 0:
222 mode0:
223 			/* no REDO, full synchronous flush */
224 			goto skip;
225 		case 1:
226 mode1:
227 			/* no REDO, full asynchronous flush */
228 			if (waitfor == MNT_WAIT)
229 				waitfor = MNT_NOWAIT;
230 			goto skip;
231 		case 2:
232 			/* REDO semantics, synchronous flush */
233 			if (hmp->version < HAMMER_VOL_VERSION_FOUR)
234 				goto mode0;
235 			mode = HAMMER_FLUSH_UNDOS_AUTO;
236 			break;
237 		case 3:
238 			/* REDO semantics, relaxed asynchronous flush */
239 			if (hmp->version < HAMMER_VOL_VERSION_FOUR)
240 				goto mode1;
241 			mode = HAMMER_FLUSH_UNDOS_RELAXED;
242 			if (waitfor == MNT_WAIT)
243 				waitfor = MNT_NOWAIT;
244 			break;
245 		case 4:
246 			/* ignore the fsync() system call */
247 			lwkt_reltoken(&hmp->fs_token);
248 			return(0);
249 		default:
250 			/* we have to do something */
251 			mode = HAMMER_FLUSH_UNDOS_RELAXED;
252 			if (waitfor == MNT_WAIT)
253 				waitfor = MNT_NOWAIT;
254 			break;
255 		}
256 
257 		/*
258 		 * Fast fsync only needs to flush the UNDO/REDO fifo if
259 		 * HAMMER_INODE_REDO is non-zero and the only modifications
260 		 * made to the file are write or write-extends.
261 		 */
262 		if ((ip->flags & HAMMER_INODE_REDO) &&
263 		    (ip->flags & HAMMER_INODE_MODMASK_NOREDO) == 0
264 		) {
265 			++hammer_count_fsyncs;
266 			hammer_flusher_flush_undos(hmp, mode);
267 			ip->redo_count = 0;
268 			lwkt_reltoken(&hmp->fs_token);
269 			return(0);
270 		}
271 
272 		/*
273 		 * REDO is enabled by fsync(), the idea being we really only
274 		 * want to lay down REDO records when programs are using
275 		 * fsync() heavily.  The first fsync() on the file starts
276 		 * the gravy train going and later fsync()s keep it hot by
277 		 * resetting the redo_count.
278 		 *
279 		 * We weren't running REDOs before now so we have to fall
280 		 * through and do a full fsync of what we have.
281 		 */
282 		if (hmp->version >= HAMMER_VOL_VERSION_FOUR &&
283 		    (hmp->flags & HAMMER_MOUNT_REDO_RECOVERY_RUN) == 0) {
284 			ip->flags |= HAMMER_INODE_REDO;
285 			ip->redo_count = 0;
286 		}
287 	}
288 skip:
289 
290 	/*
291 	 * Do a full flush sequence.
292 	 */
293 	++hammer_count_fsyncs;
294 	vfsync(ap->a_vp, waitfor, 1, NULL, NULL);
295 	hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
296 	if (waitfor == MNT_WAIT) {
297 		vn_unlock(ap->a_vp);
298 		hammer_wait_inode(ip);
299 		vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
300 	}
301 	lwkt_reltoken(&hmp->fs_token);
302 	return (ip->error);
303 }
304 
305 /*
306  * hammer_vop_read { vp, uio, ioflag, cred }
307  *
308  * MPSAFE (for the cache safe does not require fs_token)
309  */
310 static
311 int
312 hammer_vop_read(struct vop_read_args *ap)
313 {
314 	struct hammer_transaction trans;
315 	hammer_inode_t ip;
316 	hammer_mount_t hmp;
317 	off_t offset;
318 	struct buf *bp;
319 	struct uio *uio;
320 	int error;
321 	int n;
322 	int seqcount;
323 	int ioseqcount;
324 	int blksize;
325 	int bigread;
326 	int got_fstoken;
327 
328 	if (ap->a_vp->v_type != VREG)
329 		return (EINVAL);
330 	ip = VTOI(ap->a_vp);
331 	hmp = ip->hmp;
332 	error = 0;
333 	uio = ap->a_uio;
334 
335 	/*
336 	 * Allow the UIO's size to override the sequential heuristic.
337 	 */
338 	blksize = hammer_blocksize(uio->uio_offset);
339 	seqcount = (uio->uio_resid + (BKVASIZE - 1)) / BKVASIZE;
340 	ioseqcount = (ap->a_ioflag >> 16);
341 	if (seqcount < ioseqcount)
342 		seqcount = ioseqcount;
343 
344 	/*
345 	 * If reading or writing a huge amount of data we have to break
346 	 * atomicy and allow the operation to be interrupted by a signal
347 	 * or it can DOS the machine.
348 	 */
349 	bigread = (uio->uio_resid > 100 * 1024 * 1024);
350 	got_fstoken = 0;
351 
352 	/*
353 	 * Access the data typically in HAMMER_BUFSIZE blocks via the
354 	 * buffer cache, but HAMMER may use a variable block size based
355 	 * on the offset.
356 	 *
357 	 * XXX Temporary hack, delay the start transaction while we remain
358 	 *     MPSAFE.  NOTE: ino_data.size cannot change while vnode is
359 	 *     locked-shared.
360 	 */
361 	while (uio->uio_resid > 0 && uio->uio_offset < ip->ino_data.size) {
362 		int64_t base_offset;
363 		int64_t file_limit;
364 
365 		blksize = hammer_blocksize(uio->uio_offset);
366 		offset = (int)uio->uio_offset & (blksize - 1);
367 		base_offset = uio->uio_offset - offset;
368 
369 		if (bigread && (error = hammer_signal_check(ip->hmp)) != 0)
370 			break;
371 
372 		/*
373 		 * MPSAFE
374 		 */
375 		bp = getcacheblk(ap->a_vp, base_offset, blksize);
376 		if (bp) {
377 			error = 0;
378 			goto skip;
379 		}
380 
381 		/*
382 		 * MPUNSAFE
383 		 */
384 		if (got_fstoken == 0) {
385 			lwkt_gettoken(&hmp->fs_token);
386 			got_fstoken = 1;
387 			hammer_start_transaction(&trans, ip->hmp);
388 		}
389 
390 		if (hammer_cluster_enable) {
391 			/*
392 			 * Use file_limit to prevent cluster_read() from
393 			 * creating buffers of the wrong block size past
394 			 * the demarc.
395 			 */
396 			file_limit = ip->ino_data.size;
397 			if (base_offset < HAMMER_XDEMARC &&
398 			    file_limit > HAMMER_XDEMARC) {
399 				file_limit = HAMMER_XDEMARC;
400 			}
401 			error = cluster_read(ap->a_vp,
402 					     file_limit, base_offset,
403 					     blksize, uio->uio_resid,
404 					     seqcount * BKVASIZE, &bp);
405 		} else {
406 			error = bread(ap->a_vp, base_offset, blksize, &bp);
407 		}
408 		if (error) {
409 			brelse(bp);
410 			break;
411 		}
412 skip:
413 		if ((hammer_debug_io & 0x0001) && (bp->b_flags & B_IODEBUG)) {
414 			kprintf("doff %016jx read file %016jx@%016jx\n",
415 				(intmax_t)bp->b_bio2.bio_offset,
416 				(intmax_t)ip->obj_id,
417 				(intmax_t)bp->b_loffset);
418 		}
419 		bp->b_flags &= ~B_IODEBUG;
420 
421 		/* bp->b_flags |= B_CLUSTEROK; temporarily disabled */
422 		n = blksize - offset;
423 		if (n > uio->uio_resid)
424 			n = uio->uio_resid;
425 		if (n > ip->ino_data.size - uio->uio_offset)
426 			n = (int)(ip->ino_data.size - uio->uio_offset);
427 		if (got_fstoken)
428 			lwkt_reltoken(&hmp->fs_token);
429 		error = uiomove((char *)bp->b_data + offset, n, uio);
430 		if (got_fstoken)
431 			lwkt_gettoken(&hmp->fs_token);
432 
433 		/* data has a lower priority then meta-data */
434 		bp->b_flags |= B_AGE;
435 		bqrelse(bp);
436 		if (error)
437 			break;
438 		hammer_stats_file_read += n;
439 	}
440 
441 	/*
442 	 * XXX only update the atime if we had to get the MP lock.
443 	 * XXX hack hack hack, fixme.
444 	 */
445 	if (got_fstoken) {
446 		if ((ip->flags & HAMMER_INODE_RO) == 0 &&
447 		    (ip->hmp->mp->mnt_flag & MNT_NOATIME) == 0) {
448 			ip->ino_data.atime = trans.time;
449 			hammer_modify_inode(&trans, ip, HAMMER_INODE_ATIME);
450 		}
451 		hammer_done_transaction(&trans);
452 		lwkt_reltoken(&hmp->fs_token);
453 	}
454 	return (error);
455 }
456 
457 /*
458  * hammer_vop_write { vp, uio, ioflag, cred }
459  */
460 static
461 int
462 hammer_vop_write(struct vop_write_args *ap)
463 {
464 	struct hammer_transaction trans;
465 	struct hammer_inode *ip;
466 	hammer_mount_t hmp;
467 	struct uio *uio;
468 	int offset;
469 	off_t base_offset;
470 	struct buf *bp;
471 	int kflags;
472 	int error;
473 	int n;
474 	int flags;
475 	int seqcount;
476 	int bigwrite;
477 
478 	if (ap->a_vp->v_type != VREG)
479 		return (EINVAL);
480 	ip = VTOI(ap->a_vp);
481 	hmp = ip->hmp;
482 	error = 0;
483 	kflags = 0;
484 	seqcount = ap->a_ioflag >> 16;
485 
486 	if (ip->flags & HAMMER_INODE_RO)
487 		return (EROFS);
488 
489 	/*
490 	 * Create a transaction to cover the operations we perform.
491 	 */
492 	lwkt_gettoken(&hmp->fs_token);
493 	hammer_start_transaction(&trans, hmp);
494 	uio = ap->a_uio;
495 
496 	/*
497 	 * Check append mode
498 	 */
499 	if (ap->a_ioflag & IO_APPEND)
500 		uio->uio_offset = ip->ino_data.size;
501 
502 	/*
503 	 * Check for illegal write offsets.  Valid range is 0...2^63-1.
504 	 *
505 	 * NOTE: the base_off assignment is required to work around what
506 	 * I consider to be a GCC-4 optimization bug.
507 	 */
508 	if (uio->uio_offset < 0) {
509 		hammer_done_transaction(&trans);
510 		lwkt_reltoken(&hmp->fs_token);
511 		return (EFBIG);
512 	}
513 	base_offset = uio->uio_offset + uio->uio_resid;	/* work around gcc-4 */
514 	if (uio->uio_resid > 0 && base_offset <= uio->uio_offset) {
515 		hammer_done_transaction(&trans);
516 		lwkt_reltoken(&hmp->fs_token);
517 		return (EFBIG);
518 	}
519 
520 	/*
521 	 * If reading or writing a huge amount of data we have to break
522 	 * atomicy and allow the operation to be interrupted by a signal
523 	 * or it can DOS the machine.
524 	 *
525 	 * Preset redo_count so we stop generating REDOs earlier if the
526 	 * limit is exceeded.
527 	 */
528 	bigwrite = (uio->uio_resid > 100 * 1024 * 1024);
529 	if ((ip->flags & HAMMER_INODE_REDO) &&
530 	    ip->redo_count < hammer_limit_redo) {
531 		ip->redo_count += uio->uio_resid;
532 	}
533 
534 	/*
535 	 * Access the data typically in HAMMER_BUFSIZE blocks via the
536 	 * buffer cache, but HAMMER may use a variable block size based
537 	 * on the offset.
538 	 */
539 	while (uio->uio_resid > 0) {
540 		int fixsize = 0;
541 		int blksize;
542 		int blkmask;
543 		int trivial;
544 		int endofblk;
545 		off_t nsize;
546 
547 		if ((error = hammer_checkspace(hmp, HAMMER_CHKSPC_WRITE)) != 0)
548 			break;
549 		if (bigwrite && (error = hammer_signal_check(hmp)) != 0)
550 			break;
551 
552 		blksize = hammer_blocksize(uio->uio_offset);
553 
554 		/*
555 		 * Do not allow HAMMER to blow out the buffer cache.  Very
556 		 * large UIOs can lockout other processes due to bwillwrite()
557 		 * mechanics.
558 		 *
559 		 * The hammer inode is not locked during these operations.
560 		 * The vnode is locked which can interfere with the pageout
561 		 * daemon for non-UIO_NOCOPY writes but should not interfere
562 		 * with the buffer cache.  Even so, we cannot afford to
563 		 * allow the pageout daemon to build up too many dirty buffer
564 		 * cache buffers.
565 		 *
566 		 * Only call this if we aren't being recursively called from
567 		 * a virtual disk device (vn), else we may deadlock.
568 		 */
569 		if ((ap->a_ioflag & IO_RECURSE) == 0)
570 			bwillwrite(blksize);
571 
572 		/*
573 		 * Control the number of pending records associated with
574 		 * this inode.  If too many have accumulated start a
575 		 * flush.  Try to maintain a pipeline with the flusher.
576 		 */
577 		if (ip->rsv_recs >= hammer_limit_inode_recs) {
578 			hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
579 		}
580 		if (ip->rsv_recs >= hammer_limit_inode_recs * 2) {
581 			while (ip->rsv_recs >= hammer_limit_inode_recs) {
582 				tsleep(&ip->rsv_recs, 0, "hmrwww", hz);
583 			}
584 			hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
585 		}
586 
587 #if 0
588 		/*
589 		 * Do not allow HAMMER to blow out system memory by
590 		 * accumulating too many records.   Records are so well
591 		 * decoupled from the buffer cache that it is possible
592 		 * for userland to push data out to the media via
593 		 * direct-write, but build up the records queued to the
594 		 * backend faster then the backend can flush them out.
595 		 * HAMMER has hit its write limit but the frontend has
596 		 * no pushback to slow it down.
597 		 */
598 		if (hmp->rsv_recs > hammer_limit_recs / 2) {
599 			/*
600 			 * Get the inode on the flush list
601 			 */
602 			if (ip->rsv_recs >= 64)
603 				hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
604 			else if (ip->rsv_recs >= 16)
605 				hammer_flush_inode(ip, 0);
606 
607 			/*
608 			 * Keep the flusher going if the system keeps
609 			 * queueing records.
610 			 */
611 			delta = hmp->count_newrecords -
612 				hmp->last_newrecords;
613 			if (delta < 0 || delta > hammer_limit_recs / 2) {
614 				hmp->last_newrecords = hmp->count_newrecords;
615 				hammer_sync_hmp(hmp, MNT_NOWAIT);
616 			}
617 
618 			/*
619 			 * If we have gotten behind start slowing
620 			 * down the writers.
621 			 */
622 			delta = (hmp->rsv_recs - hammer_limit_recs) *
623 				hz / hammer_limit_recs;
624 			if (delta > 0)
625 				tsleep(&trans, 0, "hmrslo", delta);
626 		}
627 #endif
628 
629 		/*
630 		 * Calculate the blocksize at the current offset and figure
631 		 * out how much we can actually write.
632 		 */
633 		blkmask = blksize - 1;
634 		offset = (int)uio->uio_offset & blkmask;
635 		base_offset = uio->uio_offset & ~(int64_t)blkmask;
636 		n = blksize - offset;
637 		if (n > uio->uio_resid) {
638 			n = uio->uio_resid;
639 			endofblk = 0;
640 		} else {
641 			endofblk = 1;
642 		}
643 		nsize = uio->uio_offset + n;
644 		if (nsize > ip->ino_data.size) {
645 			if (uio->uio_offset > ip->ino_data.size)
646 				trivial = 0;
647 			else
648 				trivial = 1;
649 			nvextendbuf(ap->a_vp,
650 				    ip->ino_data.size,
651 				    nsize,
652 				    hammer_blocksize(ip->ino_data.size),
653 				    hammer_blocksize(nsize),
654 				    hammer_blockoff(ip->ino_data.size),
655 				    hammer_blockoff(nsize),
656 				    trivial);
657 			fixsize = 1;
658 			kflags |= NOTE_EXTEND;
659 		}
660 
661 		if (uio->uio_segflg == UIO_NOCOPY) {
662 			/*
663 			 * Issuing a write with the same data backing the
664 			 * buffer.  Instantiate the buffer to collect the
665 			 * backing vm pages, then read-in any missing bits.
666 			 *
667 			 * This case is used by vop_stdputpages().
668 			 */
669 			bp = getblk(ap->a_vp, base_offset,
670 				    blksize, GETBLK_BHEAVY, 0);
671 			if ((bp->b_flags & B_CACHE) == 0) {
672 				bqrelse(bp);
673 				error = bread(ap->a_vp, base_offset,
674 					      blksize, &bp);
675 			}
676 		} else if (offset == 0 && uio->uio_resid >= blksize) {
677 			/*
678 			 * Even though we are entirely overwriting the buffer
679 			 * we may still have to zero it out to avoid a
680 			 * mmap/write visibility issue.
681 			 */
682 			bp = getblk(ap->a_vp, base_offset, blksize, GETBLK_BHEAVY, 0);
683 			if ((bp->b_flags & B_CACHE) == 0)
684 				vfs_bio_clrbuf(bp);
685 		} else if (base_offset >= ip->ino_data.size) {
686 			/*
687 			 * If the base offset of the buffer is beyond the
688 			 * file EOF, we don't have to issue a read.
689 			 */
690 			bp = getblk(ap->a_vp, base_offset,
691 				    blksize, GETBLK_BHEAVY, 0);
692 			vfs_bio_clrbuf(bp);
693 		} else {
694 			/*
695 			 * Partial overwrite, read in any missing bits then
696 			 * replace the portion being written.
697 			 */
698 			error = bread(ap->a_vp, base_offset, blksize, &bp);
699 			if (error == 0)
700 				bheavy(bp);
701 		}
702 		if (error == 0) {
703 			lwkt_reltoken(&hmp->fs_token);
704 			error = uiomove(bp->b_data + offset, n, uio);
705 			lwkt_gettoken(&hmp->fs_token);
706 		}
707 
708 		/*
709 		 * Generate REDO records if enabled and redo_count will not
710 		 * exceeded the limit.
711 		 *
712 		 * If redo_count exceeds the limit we stop generating records
713 		 * and clear HAMMER_INODE_REDO.  This will cause the next
714 		 * fsync() to do a full meta-data sync instead of just an
715 		 * UNDO/REDO fifo update.
716 		 *
717 		 * When clearing HAMMER_INODE_REDO any pre-existing REDOs
718 		 * will still be tracked.  The tracks will be terminated
719 		 * when the related meta-data (including possible data
720 		 * modifications which are not tracked via REDO) is
721 		 * flushed.
722 		 */
723 		if ((ip->flags & HAMMER_INODE_REDO) && error == 0) {
724 			if (ip->redo_count < hammer_limit_redo) {
725 				bp->b_flags |= B_VFSFLAG1;
726 				error = hammer_generate_redo(&trans, ip,
727 						     base_offset + offset,
728 						     HAMMER_REDO_WRITE,
729 						     bp->b_data + offset,
730 						     (size_t)n);
731 			} else {
732 				ip->flags &= ~HAMMER_INODE_REDO;
733 			}
734 		}
735 
736 		/*
737 		 * If we screwed up we have to undo any VM size changes we
738 		 * made.
739 		 */
740 		if (error) {
741 			brelse(bp);
742 			if (fixsize) {
743 				nvtruncbuf(ap->a_vp, ip->ino_data.size,
744 					  hammer_blocksize(ip->ino_data.size),
745 					  hammer_blockoff(ip->ino_data.size));
746 			}
747 			break;
748 		}
749 		kflags |= NOTE_WRITE;
750 		hammer_stats_file_write += n;
751 		/* bp->b_flags |= B_CLUSTEROK; temporarily disabled */
752 		if (ip->ino_data.size < uio->uio_offset) {
753 			ip->ino_data.size = uio->uio_offset;
754 			flags = HAMMER_INODE_SDIRTY;
755 		} else {
756 			flags = 0;
757 		}
758 		ip->ino_data.mtime = trans.time;
759 		flags |= HAMMER_INODE_MTIME | HAMMER_INODE_BUFS;
760 		hammer_modify_inode(&trans, ip, flags);
761 
762 		/*
763 		 * Once we dirty the buffer any cached zone-X offset
764 		 * becomes invalid.  HAMMER NOTE: no-history mode cannot
765 		 * allow overwriting over the same data sector unless
766 		 * we provide UNDOs for the old data, which we don't.
767 		 */
768 		bp->b_bio2.bio_offset = NOOFFSET;
769 
770 		/*
771 		 * Final buffer disposition.
772 		 *
773 		 * Because meta-data updates are deferred, HAMMER is
774 		 * especially sensitive to excessive bdwrite()s because
775 		 * the I/O stream is not broken up by disk reads.  So the
776 		 * buffer cache simply cannot keep up.
777 		 *
778 		 * WARNING!  blksize is variable.  cluster_write() is
779 		 *	     expected to not blow up if it encounters
780 		 *	     buffers that do not match the passed blksize.
781 		 *
782 		 * NOTE!  Hammer shouldn't need to bawrite()/cluster_write().
783 		 *	  The ip->rsv_recs check should burst-flush the data.
784 		 *	  If we queue it immediately the buf could be left
785 		 *	  locked on the device queue for a very long time.
786 		 *
787 		 * NOTE!  To avoid degenerate stalls due to mismatched block
788 		 *	  sizes we only honor IO_DIRECT on the write which
789 		 *	  abuts the end of the buffer.  However, we must
790 		 *	  honor IO_SYNC in case someone is silly enough to
791 		 *	  configure a HAMMER file as swap, or when HAMMER
792 		 *	  is serving NFS (for commits).  Ick ick.
793 		 */
794 		bp->b_flags |= B_AGE;
795 		if (ap->a_ioflag & IO_SYNC) {
796 			bwrite(bp);
797 		} else if ((ap->a_ioflag & IO_DIRECT) && endofblk) {
798 			bawrite(bp);
799 		} else {
800 #if 0
801 		if (offset + n == blksize) {
802 			if (hammer_cluster_enable == 0 ||
803 			    (ap->a_vp->v_mount->mnt_flag & MNT_NOCLUSTERW)) {
804 				bawrite(bp);
805 			} else {
806 				cluster_write(bp, ip->ino_data.size,
807 					      blksize, seqcount);
808 			}
809 		} else {
810 #endif
811 			bdwrite(bp);
812 		}
813 	}
814 	hammer_done_transaction(&trans);
815 	hammer_knote(ap->a_vp, kflags);
816 	lwkt_reltoken(&hmp->fs_token);
817 	return (error);
818 }
819 
820 /*
821  * hammer_vop_access { vp, mode, cred }
822  *
823  * MPSAFE - does not require fs_token
824  */
825 static
826 int
827 hammer_vop_access(struct vop_access_args *ap)
828 {
829 	struct hammer_inode *ip = VTOI(ap->a_vp);
830 	uid_t uid;
831 	gid_t gid;
832 	int error;
833 
834 	++hammer_stats_file_iopsr;
835 	uid = hammer_to_unix_xid(&ip->ino_data.uid);
836 	gid = hammer_to_unix_xid(&ip->ino_data.gid);
837 
838 	error = vop_helper_access(ap, uid, gid, ip->ino_data.mode,
839 				  ip->ino_data.uflags);
840 	return (error);
841 }
842 
843 /*
844  * hammer_vop_advlock { vp, id, op, fl, flags }
845  *
846  * MPSAFE - does not require fs_token
847  */
848 static
849 int
850 hammer_vop_advlock(struct vop_advlock_args *ap)
851 {
852 	hammer_inode_t ip = VTOI(ap->a_vp);
853 
854 	return (lf_advlock(ap, &ip->advlock, ip->ino_data.size));
855 }
856 
857 /*
858  * hammer_vop_close { vp, fflag }
859  *
860  * We can only sync-on-close for normal closes.  XXX disabled for now.
861  */
862 static
863 int
864 hammer_vop_close(struct vop_close_args *ap)
865 {
866 #if 0
867 	struct vnode *vp = ap->a_vp;
868 	hammer_inode_t ip = VTOI(vp);
869 	int waitfor;
870 	if (ip->flags & (HAMMER_INODE_CLOSESYNC|HAMMER_INODE_CLOSEASYNC)) {
871 		if (vn_islocked(vp) == LK_EXCLUSIVE &&
872 		    (vp->v_flag & (VINACTIVE|VRECLAIMED)) == 0) {
873 			if (ip->flags & HAMMER_INODE_CLOSESYNC)
874 				waitfor = MNT_WAIT;
875 			else
876 				waitfor = MNT_NOWAIT;
877 			ip->flags &= ~(HAMMER_INODE_CLOSESYNC |
878 				       HAMMER_INODE_CLOSEASYNC);
879 			VOP_FSYNC(vp, MNT_NOWAIT, waitfor);
880 		}
881 	}
882 #endif
883 	return (vop_stdclose(ap));
884 }
885 
886 /*
887  * hammer_vop_ncreate { nch, dvp, vpp, cred, vap }
888  *
889  * The operating system has already ensured that the directory entry
890  * does not exist and done all appropriate namespace locking.
891  */
892 static
893 int
894 hammer_vop_ncreate(struct vop_ncreate_args *ap)
895 {
896 	struct hammer_transaction trans;
897 	struct hammer_inode *dip;
898 	struct hammer_inode *nip;
899 	struct nchandle *nch;
900 	hammer_mount_t hmp;
901 	int error;
902 
903 	nch = ap->a_nch;
904 	dip = VTOI(ap->a_dvp);
905 	hmp = dip->hmp;
906 
907 	if (dip->flags & HAMMER_INODE_RO)
908 		return (EROFS);
909 	if ((error = hammer_checkspace(hmp, HAMMER_CHKSPC_CREATE)) != 0)
910 		return (error);
911 
912 	/*
913 	 * Create a transaction to cover the operations we perform.
914 	 */
915 	lwkt_gettoken(&hmp->fs_token);
916 	hammer_start_transaction(&trans, hmp);
917 	++hammer_stats_file_iopsw;
918 
919 	/*
920 	 * Create a new filesystem object of the requested type.  The
921 	 * returned inode will be referenced and shared-locked to prevent
922 	 * it from being moved to the flusher.
923 	 */
924 	error = hammer_create_inode(&trans, ap->a_vap, ap->a_cred,
925 				    dip, nch->ncp->nc_name, nch->ncp->nc_nlen,
926 				    NULL, &nip);
927 	if (error) {
928 		hkprintf("hammer_create_inode error %d\n", error);
929 		hammer_done_transaction(&trans);
930 		*ap->a_vpp = NULL;
931 		lwkt_reltoken(&hmp->fs_token);
932 		return (error);
933 	}
934 
935 	/*
936 	 * Add the new filesystem object to the directory.  This will also
937 	 * bump the inode's link count.
938 	 */
939 	error = hammer_ip_add_directory(&trans, dip,
940 					nch->ncp->nc_name, nch->ncp->nc_nlen,
941 					nip);
942 	if (error)
943 		hkprintf("hammer_ip_add_directory error %d\n", error);
944 
945 	/*
946 	 * Finish up.
947 	 */
948 	if (error) {
949 		hammer_rel_inode(nip, 0);
950 		hammer_done_transaction(&trans);
951 		*ap->a_vpp = NULL;
952 	} else {
953 		error = hammer_get_vnode(nip, ap->a_vpp);
954 		hammer_done_transaction(&trans);
955 		hammer_rel_inode(nip, 0);
956 		if (error == 0) {
957 			cache_setunresolved(ap->a_nch);
958 			cache_setvp(ap->a_nch, *ap->a_vpp);
959 		}
960 		hammer_knote(ap->a_dvp, NOTE_WRITE);
961 	}
962 	lwkt_reltoken(&hmp->fs_token);
963 	return (error);
964 }
965 
966 /*
967  * hammer_vop_getattr { vp, vap }
968  *
969  * Retrieve an inode's attribute information.  When accessing inodes
970  * historically we fake the atime field to ensure consistent results.
971  * The atime field is stored in the B-Tree element and allowed to be
972  * updated without cycling the element.
973  *
974  * MPSAFE - does not require fs_token
975  */
976 static
977 int
978 hammer_vop_getattr(struct vop_getattr_args *ap)
979 {
980 	struct hammer_inode *ip = VTOI(ap->a_vp);
981 	struct vattr *vap = ap->a_vap;
982 
983 	/*
984 	 * We want the fsid to be different when accessing a filesystem
985 	 * with different as-of's so programs like diff don't think
986 	 * the files are the same.
987 	 *
988 	 * We also want the fsid to be the same when comparing snapshots,
989 	 * or when comparing mirrors (which might be backed by different
990 	 * physical devices).  HAMMER fsids are based on the PFS's
991 	 * shared_uuid field.
992 	 *
993 	 * XXX there is a chance of collision here.  The va_fsid reported
994 	 * by stat is different from the more involved fsid used in the
995 	 * mount structure.
996 	 */
997 	++hammer_stats_file_iopsr;
998 	hammer_lock_sh(&ip->lock);
999 	vap->va_fsid = ip->pfsm->fsid_udev ^ (u_int32_t)ip->obj_asof ^
1000 		       (u_int32_t)(ip->obj_asof >> 32);
1001 
1002 	vap->va_fileid = ip->ino_leaf.base.obj_id;
1003 	vap->va_mode = ip->ino_data.mode;
1004 	vap->va_nlink = ip->ino_data.nlinks;
1005 	vap->va_uid = hammer_to_unix_xid(&ip->ino_data.uid);
1006 	vap->va_gid = hammer_to_unix_xid(&ip->ino_data.gid);
1007 	vap->va_rmajor = 0;
1008 	vap->va_rminor = 0;
1009 	vap->va_size = ip->ino_data.size;
1010 
1011 	/*
1012 	 * Special case for @@PFS softlinks.  The actual size of the
1013 	 * expanded softlink is "@@0x%016llx:%05d" == 26 bytes.
1014 	 * or for MAX_TID is    "@@-1:%05d" == 10 bytes.
1015 	 */
1016 	if (ip->ino_data.obj_type == HAMMER_OBJTYPE_SOFTLINK &&
1017 	    ip->ino_data.size == 10 &&
1018 	    ip->obj_asof == HAMMER_MAX_TID &&
1019 	    ip->obj_localization == 0 &&
1020 	    strncmp(ip->ino_data.ext.symlink, "@@PFS", 5) == 0) {
1021 		    if (ip->pfsm->pfsd.mirror_flags & HAMMER_PFSD_SLAVE)
1022 			    vap->va_size = 26;
1023 		    else
1024 			    vap->va_size = 10;
1025 	}
1026 
1027 	/*
1028 	 * We must provide a consistent atime and mtime for snapshots
1029 	 * so people can do a 'tar cf - ... | md5' on them and get
1030 	 * consistent results.
1031 	 */
1032 	if (ip->flags & HAMMER_INODE_RO) {
1033 		hammer_time_to_timespec(ip->ino_data.ctime, &vap->va_atime);
1034 		hammer_time_to_timespec(ip->ino_data.ctime, &vap->va_mtime);
1035 	} else {
1036 		hammer_time_to_timespec(ip->ino_data.atime, &vap->va_atime);
1037 		hammer_time_to_timespec(ip->ino_data.mtime, &vap->va_mtime);
1038 	}
1039 	hammer_time_to_timespec(ip->ino_data.ctime, &vap->va_ctime);
1040 	vap->va_flags = ip->ino_data.uflags;
1041 	vap->va_gen = 1;	/* hammer inums are unique for all time */
1042 	vap->va_blocksize = HAMMER_BUFSIZE;
1043 	if (ip->ino_data.size >= HAMMER_XDEMARC) {
1044 		vap->va_bytes = (ip->ino_data.size + HAMMER_XBUFMASK64) &
1045 				~HAMMER_XBUFMASK64;
1046 	} else if (ip->ino_data.size > HAMMER_BUFSIZE / 2) {
1047 		vap->va_bytes = (ip->ino_data.size + HAMMER_BUFMASK64) &
1048 				~HAMMER_BUFMASK64;
1049 	} else {
1050 		vap->va_bytes = (ip->ino_data.size + 15) & ~15;
1051 	}
1052 
1053 	vap->va_type = hammer_get_vnode_type(ip->ino_data.obj_type);
1054 	vap->va_filerev = 0; 	/* XXX */
1055 	vap->va_uid_uuid = ip->ino_data.uid;
1056 	vap->va_gid_uuid = ip->ino_data.gid;
1057 	vap->va_fsid_uuid = ip->hmp->fsid;
1058 	vap->va_vaflags = VA_UID_UUID_VALID | VA_GID_UUID_VALID |
1059 			  VA_FSID_UUID_VALID;
1060 
1061 	switch (ip->ino_data.obj_type) {
1062 	case HAMMER_OBJTYPE_CDEV:
1063 	case HAMMER_OBJTYPE_BDEV:
1064 		vap->va_rmajor = ip->ino_data.rmajor;
1065 		vap->va_rminor = ip->ino_data.rminor;
1066 		break;
1067 	default:
1068 		break;
1069 	}
1070 	hammer_unlock(&ip->lock);
1071 	return(0);
1072 }
1073 
1074 /*
1075  * hammer_vop_nresolve { nch, dvp, cred }
1076  *
1077  * Locate the requested directory entry.
1078  */
1079 static
1080 int
1081 hammer_vop_nresolve(struct vop_nresolve_args *ap)
1082 {
1083 	struct hammer_transaction trans;
1084 	struct namecache *ncp;
1085 	hammer_mount_t hmp;
1086 	hammer_inode_t dip;
1087 	hammer_inode_t ip;
1088 	hammer_tid_t asof;
1089 	struct hammer_cursor cursor;
1090 	struct vnode *vp;
1091 	int64_t namekey;
1092 	int error;
1093 	int i;
1094 	int nlen;
1095 	int flags;
1096 	int ispfs;
1097 	int64_t obj_id;
1098 	u_int32_t localization;
1099 	u_int32_t max_iterations;
1100 
1101 	/*
1102 	 * Misc initialization, plus handle as-of name extensions.  Look for
1103 	 * the '@@' extension.  Note that as-of files and directories cannot
1104 	 * be modified.
1105 	 */
1106 	dip = VTOI(ap->a_dvp);
1107 	ncp = ap->a_nch->ncp;
1108 	asof = dip->obj_asof;
1109 	localization = dip->obj_localization;	/* for code consistency */
1110 	nlen = ncp->nc_nlen;
1111 	flags = dip->flags & HAMMER_INODE_RO;
1112 	ispfs = 0;
1113 	hmp = dip->hmp;
1114 
1115 	lwkt_gettoken(&hmp->fs_token);
1116 	hammer_simple_transaction(&trans, hmp);
1117 	++hammer_stats_file_iopsr;
1118 
1119 	for (i = 0; i < nlen; ++i) {
1120 		if (ncp->nc_name[i] == '@' && ncp->nc_name[i+1] == '@') {
1121 			error = hammer_str_to_tid(ncp->nc_name + i + 2,
1122 						  &ispfs, &asof, &localization);
1123 			if (error != 0) {
1124 				i = nlen;
1125 				break;
1126 			}
1127 			if (asof != HAMMER_MAX_TID)
1128 				flags |= HAMMER_INODE_RO;
1129 			break;
1130 		}
1131 	}
1132 	nlen = i;
1133 
1134 	/*
1135 	 * If this is a PFS softlink we dive into the PFS
1136 	 */
1137 	if (ispfs && nlen == 0) {
1138 		ip = hammer_get_inode(&trans, dip, HAMMER_OBJID_ROOT,
1139 				      asof, localization,
1140 				      flags, &error);
1141 		if (error == 0) {
1142 			error = hammer_get_vnode(ip, &vp);
1143 			hammer_rel_inode(ip, 0);
1144 		} else {
1145 			vp = NULL;
1146 		}
1147 		if (error == 0) {
1148 			vn_unlock(vp);
1149 			cache_setvp(ap->a_nch, vp);
1150 			vrele(vp);
1151 		}
1152 		goto done;
1153 	}
1154 
1155 	/*
1156 	 * If there is no path component the time extension is relative to dip.
1157 	 * e.g. "fubar/@@<snapshot>"
1158 	 *
1159 	 * "." is handled by the kernel, but ".@@<snapshot>" is not.
1160 	 * e.g. "fubar/.@@<snapshot>"
1161 	 *
1162 	 * ".." is handled by the kernel.  We do not currently handle
1163 	 * "..@<snapshot>".
1164 	 */
1165 	if (nlen == 0 || (nlen == 1 && ncp->nc_name[0] == '.')) {
1166 		ip = hammer_get_inode(&trans, dip, dip->obj_id,
1167 				      asof, dip->obj_localization,
1168 				      flags, &error);
1169 		if (error == 0) {
1170 			error = hammer_get_vnode(ip, &vp);
1171 			hammer_rel_inode(ip, 0);
1172 		} else {
1173 			vp = NULL;
1174 		}
1175 		if (error == 0) {
1176 			vn_unlock(vp);
1177 			cache_setvp(ap->a_nch, vp);
1178 			vrele(vp);
1179 		}
1180 		goto done;
1181 	}
1182 
1183 	/*
1184 	 * Calculate the namekey and setup the key range for the scan.  This
1185 	 * works kinda like a chained hash table where the lower 32 bits
1186 	 * of the namekey synthesize the chain.
1187 	 *
1188 	 * The key range is inclusive of both key_beg and key_end.
1189 	 */
1190 	namekey = hammer_directory_namekey(dip, ncp->nc_name, nlen,
1191 					   &max_iterations);
1192 
1193 	error = hammer_init_cursor(&trans, &cursor, &dip->cache[1], dip);
1194 	cursor.key_beg.localization = dip->obj_localization +
1195 				      hammer_dir_localization(dip);
1196         cursor.key_beg.obj_id = dip->obj_id;
1197 	cursor.key_beg.key = namekey;
1198         cursor.key_beg.create_tid = 0;
1199         cursor.key_beg.delete_tid = 0;
1200         cursor.key_beg.rec_type = HAMMER_RECTYPE_DIRENTRY;
1201         cursor.key_beg.obj_type = 0;
1202 
1203 	cursor.key_end = cursor.key_beg;
1204 	cursor.key_end.key += max_iterations;
1205 	cursor.asof = asof;
1206 	cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF;
1207 
1208 	/*
1209 	 * Scan all matching records (the chain), locate the one matching
1210 	 * the requested path component.
1211 	 *
1212 	 * The hammer_ip_*() functions merge in-memory records with on-disk
1213 	 * records for the purposes of the search.
1214 	 */
1215 	obj_id = 0;
1216 	localization = HAMMER_DEF_LOCALIZATION;
1217 
1218 	if (error == 0) {
1219 		error = hammer_ip_first(&cursor);
1220 		while (error == 0) {
1221 			error = hammer_ip_resolve_data(&cursor);
1222 			if (error)
1223 				break;
1224 			if (nlen == cursor.leaf->data_len - HAMMER_ENTRY_NAME_OFF &&
1225 			    bcmp(ncp->nc_name, cursor.data->entry.name, nlen) == 0) {
1226 				obj_id = cursor.data->entry.obj_id;
1227 				localization = cursor.data->entry.localization;
1228 				break;
1229 			}
1230 			error = hammer_ip_next(&cursor);
1231 		}
1232 	}
1233 	hammer_done_cursor(&cursor);
1234 
1235 	/*
1236 	 * Lookup the obj_id.  This should always succeed.  If it does not
1237 	 * the filesystem may be damaged and we return a dummy inode.
1238 	 */
1239 	if (error == 0) {
1240 		ip = hammer_get_inode(&trans, dip, obj_id,
1241 				      asof, localization,
1242 				      flags, &error);
1243 		if (error == ENOENT) {
1244 			kprintf("HAMMER: WARNING: Missing "
1245 				"inode for dirent \"%s\"\n"
1246 				"\tobj_id = %016llx, asof=%016llx, lo=%08x\n",
1247 				ncp->nc_name,
1248 				(long long)obj_id, (long long)asof,
1249 				localization);
1250 			error = 0;
1251 			ip = hammer_get_dummy_inode(&trans, dip, obj_id,
1252 						    asof, localization,
1253 						    flags, &error);
1254 		}
1255 		if (error == 0) {
1256 			error = hammer_get_vnode(ip, &vp);
1257 			hammer_rel_inode(ip, 0);
1258 		} else {
1259 			vp = NULL;
1260 		}
1261 		if (error == 0) {
1262 			vn_unlock(vp);
1263 			cache_setvp(ap->a_nch, vp);
1264 			vrele(vp);
1265 		}
1266 	} else if (error == ENOENT) {
1267 		cache_setvp(ap->a_nch, NULL);
1268 	}
1269 done:
1270 	hammer_done_transaction(&trans);
1271 	lwkt_reltoken(&hmp->fs_token);
1272 	return (error);
1273 }
1274 
1275 /*
1276  * hammer_vop_nlookupdotdot { dvp, vpp, cred }
1277  *
1278  * Locate the parent directory of a directory vnode.
1279  *
1280  * dvp is referenced but not locked.  *vpp must be returned referenced and
1281  * locked.  A parent_obj_id of 0 does not necessarily indicate that we are
1282  * at the root, instead it could indicate that the directory we were in was
1283  * removed.
1284  *
1285  * NOTE: as-of sequences are not linked into the directory structure.  If
1286  * we are at the root with a different asof then the mount point, reload
1287  * the same directory with the mount point's asof.   I'm not sure what this
1288  * will do to NFS.  We encode ASOF stamps in NFS file handles so it might not
1289  * get confused, but it hasn't been tested.
1290  */
1291 static
1292 int
1293 hammer_vop_nlookupdotdot(struct vop_nlookupdotdot_args *ap)
1294 {
1295 	struct hammer_transaction trans;
1296 	struct hammer_inode *dip;
1297 	struct hammer_inode *ip;
1298 	hammer_mount_t hmp;
1299 	int64_t parent_obj_id;
1300 	u_int32_t parent_obj_localization;
1301 	hammer_tid_t asof;
1302 	int error;
1303 
1304 	dip = VTOI(ap->a_dvp);
1305 	asof = dip->obj_asof;
1306 	hmp = dip->hmp;
1307 
1308 	/*
1309 	 * Whos are parent?  This could be the root of a pseudo-filesystem
1310 	 * whos parent is in another localization domain.
1311 	 */
1312 	lwkt_gettoken(&hmp->fs_token);
1313 	parent_obj_id = dip->ino_data.parent_obj_id;
1314 	if (dip->obj_id == HAMMER_OBJID_ROOT)
1315 		parent_obj_localization = dip->ino_data.ext.obj.parent_obj_localization;
1316 	else
1317 		parent_obj_localization = dip->obj_localization;
1318 
1319 	if (parent_obj_id == 0) {
1320 		if (dip->obj_id == HAMMER_OBJID_ROOT &&
1321 		   asof != hmp->asof) {
1322 			parent_obj_id = dip->obj_id;
1323 			asof = hmp->asof;
1324 			*ap->a_fakename = kmalloc(19, M_TEMP, M_WAITOK);
1325 			ksnprintf(*ap->a_fakename, 19, "0x%016llx",
1326 				  (long long)dip->obj_asof);
1327 		} else {
1328 			*ap->a_vpp = NULL;
1329 			lwkt_reltoken(&hmp->fs_token);
1330 			return ENOENT;
1331 		}
1332 	}
1333 
1334 	hammer_simple_transaction(&trans, hmp);
1335 	++hammer_stats_file_iopsr;
1336 
1337 	ip = hammer_get_inode(&trans, dip, parent_obj_id,
1338 			      asof, parent_obj_localization,
1339 			      dip->flags, &error);
1340 	if (ip) {
1341 		error = hammer_get_vnode(ip, ap->a_vpp);
1342 		hammer_rel_inode(ip, 0);
1343 	} else {
1344 		*ap->a_vpp = NULL;
1345 	}
1346 	hammer_done_transaction(&trans);
1347 	lwkt_reltoken(&hmp->fs_token);
1348 	return (error);
1349 }
1350 
1351 /*
1352  * hammer_vop_nlink { nch, dvp, vp, cred }
1353  */
1354 static
1355 int
1356 hammer_vop_nlink(struct vop_nlink_args *ap)
1357 {
1358 	struct hammer_transaction trans;
1359 	struct hammer_inode *dip;
1360 	struct hammer_inode *ip;
1361 	struct nchandle *nch;
1362 	hammer_mount_t hmp;
1363 	int error;
1364 
1365 	if (ap->a_dvp->v_mount != ap->a_vp->v_mount)
1366 		return(EXDEV);
1367 
1368 	nch = ap->a_nch;
1369 	dip = VTOI(ap->a_dvp);
1370 	ip = VTOI(ap->a_vp);
1371 	hmp = dip->hmp;
1372 
1373 	if (dip->obj_localization != ip->obj_localization)
1374 		return(EXDEV);
1375 
1376 	if (dip->flags & HAMMER_INODE_RO)
1377 		return (EROFS);
1378 	if (ip->flags & HAMMER_INODE_RO)
1379 		return (EROFS);
1380 	if ((error = hammer_checkspace(hmp, HAMMER_CHKSPC_CREATE)) != 0)
1381 		return (error);
1382 
1383 	/*
1384 	 * Create a transaction to cover the operations we perform.
1385 	 */
1386 	lwkt_gettoken(&hmp->fs_token);
1387 	hammer_start_transaction(&trans, hmp);
1388 	++hammer_stats_file_iopsw;
1389 
1390 	/*
1391 	 * Add the filesystem object to the directory.  Note that neither
1392 	 * dip nor ip are referenced or locked, but their vnodes are
1393 	 * referenced.  This function will bump the inode's link count.
1394 	 */
1395 	error = hammer_ip_add_directory(&trans, dip,
1396 					nch->ncp->nc_name, nch->ncp->nc_nlen,
1397 					ip);
1398 
1399 	/*
1400 	 * Finish up.
1401 	 */
1402 	if (error == 0) {
1403 		cache_setunresolved(nch);
1404 		cache_setvp(nch, ap->a_vp);
1405 	}
1406 	hammer_done_transaction(&trans);
1407 	hammer_knote(ap->a_vp, NOTE_LINK);
1408 	hammer_knote(ap->a_dvp, NOTE_WRITE);
1409 	lwkt_reltoken(&hmp->fs_token);
1410 	return (error);
1411 }
1412 
1413 /*
1414  * hammer_vop_nmkdir { nch, dvp, vpp, cred, vap }
1415  *
1416  * The operating system has already ensured that the directory entry
1417  * does not exist and done all appropriate namespace locking.
1418  */
1419 static
1420 int
1421 hammer_vop_nmkdir(struct vop_nmkdir_args *ap)
1422 {
1423 	struct hammer_transaction trans;
1424 	struct hammer_inode *dip;
1425 	struct hammer_inode *nip;
1426 	struct nchandle *nch;
1427 	hammer_mount_t hmp;
1428 	int error;
1429 
1430 	nch = ap->a_nch;
1431 	dip = VTOI(ap->a_dvp);
1432 	hmp = dip->hmp;
1433 
1434 	if (dip->flags & HAMMER_INODE_RO)
1435 		return (EROFS);
1436 	if ((error = hammer_checkspace(hmp, HAMMER_CHKSPC_CREATE)) != 0)
1437 		return (error);
1438 
1439 	/*
1440 	 * Create a transaction to cover the operations we perform.
1441 	 */
1442 	lwkt_gettoken(&hmp->fs_token);
1443 	hammer_start_transaction(&trans, hmp);
1444 	++hammer_stats_file_iopsw;
1445 
1446 	/*
1447 	 * Create a new filesystem object of the requested type.  The
1448 	 * returned inode will be referenced but not locked.
1449 	 */
1450 	error = hammer_create_inode(&trans, ap->a_vap, ap->a_cred,
1451 				    dip, nch->ncp->nc_name, nch->ncp->nc_nlen,
1452 				    NULL, &nip);
1453 	if (error) {
1454 		hkprintf("hammer_mkdir error %d\n", error);
1455 		hammer_done_transaction(&trans);
1456 		*ap->a_vpp = NULL;
1457 		lwkt_reltoken(&hmp->fs_token);
1458 		return (error);
1459 	}
1460 	/*
1461 	 * Add the new filesystem object to the directory.  This will also
1462 	 * bump the inode's link count.
1463 	 */
1464 	error = hammer_ip_add_directory(&trans, dip,
1465 					nch->ncp->nc_name, nch->ncp->nc_nlen,
1466 					nip);
1467 	if (error)
1468 		hkprintf("hammer_mkdir (add) error %d\n", error);
1469 
1470 	/*
1471 	 * Finish up.
1472 	 */
1473 	if (error) {
1474 		hammer_rel_inode(nip, 0);
1475 		*ap->a_vpp = NULL;
1476 	} else {
1477 		error = hammer_get_vnode(nip, ap->a_vpp);
1478 		hammer_rel_inode(nip, 0);
1479 		if (error == 0) {
1480 			cache_setunresolved(ap->a_nch);
1481 			cache_setvp(ap->a_nch, *ap->a_vpp);
1482 		}
1483 	}
1484 	hammer_done_transaction(&trans);
1485 	if (error == 0)
1486 		hammer_knote(ap->a_dvp, NOTE_WRITE | NOTE_LINK);
1487 	lwkt_reltoken(&hmp->fs_token);
1488 	return (error);
1489 }
1490 
1491 /*
1492  * hammer_vop_nmknod { nch, dvp, vpp, cred, vap }
1493  *
1494  * The operating system has already ensured that the directory entry
1495  * does not exist and done all appropriate namespace locking.
1496  */
1497 static
1498 int
1499 hammer_vop_nmknod(struct vop_nmknod_args *ap)
1500 {
1501 	struct hammer_transaction trans;
1502 	struct hammer_inode *dip;
1503 	struct hammer_inode *nip;
1504 	struct nchandle *nch;
1505 	hammer_mount_t hmp;
1506 	int error;
1507 
1508 	nch = ap->a_nch;
1509 	dip = VTOI(ap->a_dvp);
1510 	hmp = dip->hmp;
1511 
1512 	if (dip->flags & HAMMER_INODE_RO)
1513 		return (EROFS);
1514 	if ((error = hammer_checkspace(hmp, HAMMER_CHKSPC_CREATE)) != 0)
1515 		return (error);
1516 
1517 	/*
1518 	 * Create a transaction to cover the operations we perform.
1519 	 */
1520 	lwkt_gettoken(&hmp->fs_token);
1521 	hammer_start_transaction(&trans, hmp);
1522 	++hammer_stats_file_iopsw;
1523 
1524 	/*
1525 	 * Create a new filesystem object of the requested type.  The
1526 	 * returned inode will be referenced but not locked.
1527 	 *
1528 	 * If mknod specifies a directory a pseudo-fs is created.
1529 	 */
1530 	error = hammer_create_inode(&trans, ap->a_vap, ap->a_cred,
1531 				    dip, nch->ncp->nc_name, nch->ncp->nc_nlen,
1532 				    NULL, &nip);
1533 	if (error) {
1534 		hammer_done_transaction(&trans);
1535 		*ap->a_vpp = NULL;
1536 		lwkt_reltoken(&hmp->fs_token);
1537 		return (error);
1538 	}
1539 
1540 	/*
1541 	 * Add the new filesystem object to the directory.  This will also
1542 	 * bump the inode's link count.
1543 	 */
1544 	error = hammer_ip_add_directory(&trans, dip,
1545 					nch->ncp->nc_name, nch->ncp->nc_nlen,
1546 					nip);
1547 
1548 	/*
1549 	 * Finish up.
1550 	 */
1551 	if (error) {
1552 		hammer_rel_inode(nip, 0);
1553 		*ap->a_vpp = NULL;
1554 	} else {
1555 		error = hammer_get_vnode(nip, ap->a_vpp);
1556 		hammer_rel_inode(nip, 0);
1557 		if (error == 0) {
1558 			cache_setunresolved(ap->a_nch);
1559 			cache_setvp(ap->a_nch, *ap->a_vpp);
1560 		}
1561 	}
1562 	hammer_done_transaction(&trans);
1563 	if (error == 0)
1564 		hammer_knote(ap->a_dvp, NOTE_WRITE);
1565 	lwkt_reltoken(&hmp->fs_token);
1566 	return (error);
1567 }
1568 
1569 /*
1570  * hammer_vop_open { vp, mode, cred, fp }
1571  *
1572  * MPSAFE (does not require fs_token)
1573  */
1574 static
1575 int
1576 hammer_vop_open(struct vop_open_args *ap)
1577 {
1578 	hammer_inode_t ip;
1579 
1580 	++hammer_stats_file_iopsr;
1581 	ip = VTOI(ap->a_vp);
1582 
1583 	if ((ap->a_mode & FWRITE) && (ip->flags & HAMMER_INODE_RO))
1584 		return (EROFS);
1585 	return(vop_stdopen(ap));
1586 }
1587 
1588 /*
1589  * hammer_vop_print { vp }
1590  */
1591 static
1592 int
1593 hammer_vop_print(struct vop_print_args *ap)
1594 {
1595 	return EOPNOTSUPP;
1596 }
1597 
1598 /*
1599  * hammer_vop_readdir { vp, uio, cred, *eofflag, *ncookies, off_t **cookies }
1600  */
1601 static
1602 int
1603 hammer_vop_readdir(struct vop_readdir_args *ap)
1604 {
1605 	struct hammer_transaction trans;
1606 	struct hammer_cursor cursor;
1607 	struct hammer_inode *ip;
1608 	hammer_mount_t hmp;
1609 	struct uio *uio;
1610 	hammer_base_elm_t base;
1611 	int error;
1612 	int cookie_index;
1613 	int ncookies;
1614 	off_t *cookies;
1615 	off_t saveoff;
1616 	int r;
1617 	int dtype;
1618 
1619 	++hammer_stats_file_iopsr;
1620 	ip = VTOI(ap->a_vp);
1621 	uio = ap->a_uio;
1622 	saveoff = uio->uio_offset;
1623 	hmp = ip->hmp;
1624 
1625 	if (ap->a_ncookies) {
1626 		ncookies = uio->uio_resid / 16 + 1;
1627 		if (ncookies > 1024)
1628 			ncookies = 1024;
1629 		cookies = kmalloc(ncookies * sizeof(off_t), M_TEMP, M_WAITOK);
1630 		cookie_index = 0;
1631 	} else {
1632 		ncookies = -1;
1633 		cookies = NULL;
1634 		cookie_index = 0;
1635 	}
1636 
1637 	lwkt_gettoken(&hmp->fs_token);
1638 	hammer_simple_transaction(&trans, hmp);
1639 
1640 	/*
1641 	 * Handle artificial entries
1642 	 *
1643 	 * It should be noted that the minimum value for a directory
1644 	 * hash key on-media is 0x0000000100000000, so we can use anything
1645 	 * less then that to represent our 'special' key space.
1646 	 */
1647 	error = 0;
1648 	if (saveoff == 0) {
1649 		r = vop_write_dirent(&error, uio, ip->obj_id, DT_DIR, 1, ".");
1650 		if (r)
1651 			goto done;
1652 		if (cookies)
1653 			cookies[cookie_index] = saveoff;
1654 		++saveoff;
1655 		++cookie_index;
1656 		if (cookie_index == ncookies)
1657 			goto done;
1658 	}
1659 	if (saveoff == 1) {
1660 		if (ip->ino_data.parent_obj_id) {
1661 			r = vop_write_dirent(&error, uio,
1662 					     ip->ino_data.parent_obj_id,
1663 					     DT_DIR, 2, "..");
1664 		} else {
1665 			r = vop_write_dirent(&error, uio,
1666 					     ip->obj_id, DT_DIR, 2, "..");
1667 		}
1668 		if (r)
1669 			goto done;
1670 		if (cookies)
1671 			cookies[cookie_index] = saveoff;
1672 		++saveoff;
1673 		++cookie_index;
1674 		if (cookie_index == ncookies)
1675 			goto done;
1676 	}
1677 
1678 	/*
1679 	 * Key range (begin and end inclusive) to scan.  Directory keys
1680 	 * directly translate to a 64 bit 'seek' position.
1681 	 */
1682 	hammer_init_cursor(&trans, &cursor, &ip->cache[1], ip);
1683 	cursor.key_beg.localization = ip->obj_localization +
1684 				      hammer_dir_localization(ip);
1685 	cursor.key_beg.obj_id = ip->obj_id;
1686 	cursor.key_beg.create_tid = 0;
1687 	cursor.key_beg.delete_tid = 0;
1688         cursor.key_beg.rec_type = HAMMER_RECTYPE_DIRENTRY;
1689 	cursor.key_beg.obj_type = 0;
1690 	cursor.key_beg.key = saveoff;
1691 
1692 	cursor.key_end = cursor.key_beg;
1693 	cursor.key_end.key = HAMMER_MAX_KEY;
1694 	cursor.asof = ip->obj_asof;
1695 	cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF;
1696 
1697 	error = hammer_ip_first(&cursor);
1698 
1699 	while (error == 0) {
1700 		error = hammer_ip_resolve_data(&cursor);
1701 		if (error)
1702 			break;
1703 		base = &cursor.leaf->base;
1704 		saveoff = base->key;
1705 		KKASSERT(cursor.leaf->data_len > HAMMER_ENTRY_NAME_OFF);
1706 
1707 		if (base->obj_id != ip->obj_id)
1708 			panic("readdir: bad record at %p", cursor.node);
1709 
1710 		/*
1711 		 * Convert pseudo-filesystems into softlinks
1712 		 */
1713 		dtype = hammer_get_dtype(cursor.leaf->base.obj_type);
1714 		r = vop_write_dirent(
1715 			     &error, uio, cursor.data->entry.obj_id,
1716 			     dtype,
1717 			     cursor.leaf->data_len - HAMMER_ENTRY_NAME_OFF ,
1718 			     (void *)cursor.data->entry.name);
1719 		if (r)
1720 			break;
1721 		++saveoff;
1722 		if (cookies)
1723 			cookies[cookie_index] = base->key;
1724 		++cookie_index;
1725 		if (cookie_index == ncookies)
1726 			break;
1727 		error = hammer_ip_next(&cursor);
1728 	}
1729 	hammer_done_cursor(&cursor);
1730 
1731 done:
1732 	hammer_done_transaction(&trans);
1733 
1734 	if (ap->a_eofflag)
1735 		*ap->a_eofflag = (error == ENOENT);
1736 	uio->uio_offset = saveoff;
1737 	if (error && cookie_index == 0) {
1738 		if (error == ENOENT)
1739 			error = 0;
1740 		if (cookies) {
1741 			kfree(cookies, M_TEMP);
1742 			*ap->a_ncookies = 0;
1743 			*ap->a_cookies = NULL;
1744 		}
1745 	} else {
1746 		if (error == ENOENT)
1747 			error = 0;
1748 		if (cookies) {
1749 			*ap->a_ncookies = cookie_index;
1750 			*ap->a_cookies = cookies;
1751 		}
1752 	}
1753 	lwkt_reltoken(&hmp->fs_token);
1754 	return(error);
1755 }
1756 
1757 /*
1758  * hammer_vop_readlink { vp, uio, cred }
1759  */
1760 static
1761 int
1762 hammer_vop_readlink(struct vop_readlink_args *ap)
1763 {
1764 	struct hammer_transaction trans;
1765 	struct hammer_cursor cursor;
1766 	struct hammer_inode *ip;
1767 	hammer_mount_t hmp;
1768 	char buf[32];
1769 	u_int32_t localization;
1770 	hammer_pseudofs_inmem_t pfsm;
1771 	int error;
1772 
1773 	ip = VTOI(ap->a_vp);
1774 	hmp = ip->hmp;
1775 
1776 	lwkt_gettoken(&hmp->fs_token);
1777 
1778 	/*
1779 	 * Shortcut if the symlink data was stuffed into ino_data.
1780 	 *
1781 	 * Also expand special "@@PFS%05d" softlinks (expansion only
1782 	 * occurs for non-historical (current) accesses made from the
1783 	 * primary filesystem).
1784 	 */
1785 	if (ip->ino_data.size <= HAMMER_INODE_BASESYMLEN) {
1786 		char *ptr;
1787 		int bytes;
1788 
1789 		ptr = ip->ino_data.ext.symlink;
1790 		bytes = (int)ip->ino_data.size;
1791 		if (bytes == 10 &&
1792 		    ip->obj_asof == HAMMER_MAX_TID &&
1793 		    ip->obj_localization == 0 &&
1794 		    strncmp(ptr, "@@PFS", 5) == 0) {
1795 			hammer_simple_transaction(&trans, hmp);
1796 			bcopy(ptr + 5, buf, 5);
1797 			buf[5] = 0;
1798 			localization = strtoul(buf, NULL, 10) << 16;
1799 			pfsm = hammer_load_pseudofs(&trans, localization,
1800 						    &error);
1801 			if (error == 0) {
1802 				if (pfsm->pfsd.mirror_flags &
1803 				    HAMMER_PFSD_SLAVE) {
1804 					/* vap->va_size == 26 */
1805 					ksnprintf(buf, sizeof(buf),
1806 						  "@@0x%016llx:%05d",
1807 						  (long long)pfsm->pfsd.sync_end_tid,
1808 						  localization >> 16);
1809 				} else {
1810 					/* vap->va_size == 10 */
1811 					ksnprintf(buf, sizeof(buf),
1812 						  "@@-1:%05d",
1813 						  localization >> 16);
1814 #if 0
1815 					ksnprintf(buf, sizeof(buf),
1816 						  "@@0x%016llx:%05d",
1817 						  (long long)HAMMER_MAX_TID,
1818 						  localization >> 16);
1819 #endif
1820 				}
1821 				ptr = buf;
1822 				bytes = strlen(buf);
1823 			}
1824 			if (pfsm)
1825 				hammer_rel_pseudofs(hmp, pfsm);
1826 			hammer_done_transaction(&trans);
1827 		}
1828 		error = uiomove(ptr, bytes, ap->a_uio);
1829 		lwkt_reltoken(&hmp->fs_token);
1830 		return(error);
1831 	}
1832 
1833 	/*
1834 	 * Long version
1835 	 */
1836 	hammer_simple_transaction(&trans, hmp);
1837 	++hammer_stats_file_iopsr;
1838 	hammer_init_cursor(&trans, &cursor, &ip->cache[1], ip);
1839 
1840 	/*
1841 	 * Key range (begin and end inclusive) to scan.  Directory keys
1842 	 * directly translate to a 64 bit 'seek' position.
1843 	 */
1844 	cursor.key_beg.localization = ip->obj_localization +
1845 				      HAMMER_LOCALIZE_MISC;
1846 	cursor.key_beg.obj_id = ip->obj_id;
1847 	cursor.key_beg.create_tid = 0;
1848 	cursor.key_beg.delete_tid = 0;
1849         cursor.key_beg.rec_type = HAMMER_RECTYPE_FIX;
1850 	cursor.key_beg.obj_type = 0;
1851 	cursor.key_beg.key = HAMMER_FIXKEY_SYMLINK;
1852 	cursor.asof = ip->obj_asof;
1853 	cursor.flags |= HAMMER_CURSOR_ASOF;
1854 
1855 	error = hammer_ip_lookup(&cursor);
1856 	if (error == 0) {
1857 		error = hammer_ip_resolve_data(&cursor);
1858 		if (error == 0) {
1859 			KKASSERT(cursor.leaf->data_len >=
1860 				 HAMMER_SYMLINK_NAME_OFF);
1861 			error = uiomove(cursor.data->symlink.name,
1862 					cursor.leaf->data_len -
1863 						HAMMER_SYMLINK_NAME_OFF,
1864 					ap->a_uio);
1865 		}
1866 	}
1867 	hammer_done_cursor(&cursor);
1868 	hammer_done_transaction(&trans);
1869 	lwkt_reltoken(&hmp->fs_token);
1870 	return(error);
1871 }
1872 
1873 /*
1874  * hammer_vop_nremove { nch, dvp, cred }
1875  */
1876 static
1877 int
1878 hammer_vop_nremove(struct vop_nremove_args *ap)
1879 {
1880 	struct hammer_transaction trans;
1881 	struct hammer_inode *dip;
1882 	hammer_mount_t hmp;
1883 	int error;
1884 
1885 	dip = VTOI(ap->a_dvp);
1886 	hmp = dip->hmp;
1887 
1888 	if (hammer_nohistory(dip) == 0 &&
1889 	    (error = hammer_checkspace(hmp, HAMMER_CHKSPC_REMOVE)) != 0) {
1890 		return (error);
1891 	}
1892 
1893 	lwkt_gettoken(&hmp->fs_token);
1894 	hammer_start_transaction(&trans, hmp);
1895 	++hammer_stats_file_iopsw;
1896 	error = hammer_dounlink(&trans, ap->a_nch, ap->a_dvp, ap->a_cred, 0, 0);
1897 	hammer_done_transaction(&trans);
1898 	if (error == 0)
1899 		hammer_knote(ap->a_dvp, NOTE_WRITE);
1900 	lwkt_reltoken(&hmp->fs_token);
1901 	return (error);
1902 }
1903 
1904 /*
1905  * hammer_vop_nrename { fnch, tnch, fdvp, tdvp, cred }
1906  */
1907 static
1908 int
1909 hammer_vop_nrename(struct vop_nrename_args *ap)
1910 {
1911 	struct hammer_transaction trans;
1912 	struct namecache *fncp;
1913 	struct namecache *tncp;
1914 	struct hammer_inode *fdip;
1915 	struct hammer_inode *tdip;
1916 	struct hammer_inode *ip;
1917 	hammer_mount_t hmp;
1918 	struct hammer_cursor cursor;
1919 	int64_t namekey;
1920 	u_int32_t max_iterations;
1921 	int nlen, error;
1922 
1923 	if (ap->a_fdvp->v_mount != ap->a_tdvp->v_mount)
1924 		return(EXDEV);
1925 	if (ap->a_fdvp->v_mount != ap->a_fnch->ncp->nc_vp->v_mount)
1926 		return(EXDEV);
1927 
1928 	fdip = VTOI(ap->a_fdvp);
1929 	tdip = VTOI(ap->a_tdvp);
1930 	fncp = ap->a_fnch->ncp;
1931 	tncp = ap->a_tnch->ncp;
1932 	ip = VTOI(fncp->nc_vp);
1933 	KKASSERT(ip != NULL);
1934 
1935 	hmp = ip->hmp;
1936 
1937 	if (fdip->obj_localization != tdip->obj_localization)
1938 		return(EXDEV);
1939 	if (fdip->obj_localization != ip->obj_localization)
1940 		return(EXDEV);
1941 
1942 	if (fdip->flags & HAMMER_INODE_RO)
1943 		return (EROFS);
1944 	if (tdip->flags & HAMMER_INODE_RO)
1945 		return (EROFS);
1946 	if (ip->flags & HAMMER_INODE_RO)
1947 		return (EROFS);
1948 	if ((error = hammer_checkspace(hmp, HAMMER_CHKSPC_CREATE)) != 0)
1949 		return (error);
1950 
1951 	lwkt_gettoken(&hmp->fs_token);
1952 	hammer_start_transaction(&trans, hmp);
1953 	++hammer_stats_file_iopsw;
1954 
1955 	/*
1956 	 * Remove tncp from the target directory and then link ip as
1957 	 * tncp. XXX pass trans to dounlink
1958 	 *
1959 	 * Force the inode sync-time to match the transaction so it is
1960 	 * in-sync with the creation of the target directory entry.
1961 	 */
1962 	error = hammer_dounlink(&trans, ap->a_tnch, ap->a_tdvp,
1963 				ap->a_cred, 0, -1);
1964 	if (error == 0 || error == ENOENT) {
1965 		error = hammer_ip_add_directory(&trans, tdip,
1966 						tncp->nc_name, tncp->nc_nlen,
1967 						ip);
1968 		if (error == 0) {
1969 			ip->ino_data.parent_obj_id = tdip->obj_id;
1970 			ip->ino_data.ctime = trans.time;
1971 			hammer_modify_inode(&trans, ip, HAMMER_INODE_DDIRTY);
1972 		}
1973 	}
1974 	if (error)
1975 		goto failed; /* XXX */
1976 
1977 	/*
1978 	 * Locate the record in the originating directory and remove it.
1979 	 *
1980 	 * Calculate the namekey and setup the key range for the scan.  This
1981 	 * works kinda like a chained hash table where the lower 32 bits
1982 	 * of the namekey synthesize the chain.
1983 	 *
1984 	 * The key range is inclusive of both key_beg and key_end.
1985 	 */
1986 	namekey = hammer_directory_namekey(fdip, fncp->nc_name, fncp->nc_nlen,
1987 					   &max_iterations);
1988 retry:
1989 	hammer_init_cursor(&trans, &cursor, &fdip->cache[1], fdip);
1990 	cursor.key_beg.localization = fdip->obj_localization +
1991 				      hammer_dir_localization(fdip);
1992         cursor.key_beg.obj_id = fdip->obj_id;
1993 	cursor.key_beg.key = namekey;
1994         cursor.key_beg.create_tid = 0;
1995         cursor.key_beg.delete_tid = 0;
1996         cursor.key_beg.rec_type = HAMMER_RECTYPE_DIRENTRY;
1997         cursor.key_beg.obj_type = 0;
1998 
1999 	cursor.key_end = cursor.key_beg;
2000 	cursor.key_end.key += max_iterations;
2001 	cursor.asof = fdip->obj_asof;
2002 	cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF;
2003 
2004 	/*
2005 	 * Scan all matching records (the chain), locate the one matching
2006 	 * the requested path component.
2007 	 *
2008 	 * The hammer_ip_*() functions merge in-memory records with on-disk
2009 	 * records for the purposes of the search.
2010 	 */
2011 	error = hammer_ip_first(&cursor);
2012 	while (error == 0) {
2013 		if (hammer_ip_resolve_data(&cursor) != 0)
2014 			break;
2015 		nlen = cursor.leaf->data_len - HAMMER_ENTRY_NAME_OFF;
2016 		KKASSERT(nlen > 0);
2017 		if (fncp->nc_nlen == nlen &&
2018 		    bcmp(fncp->nc_name, cursor.data->entry.name, nlen) == 0) {
2019 			break;
2020 		}
2021 		error = hammer_ip_next(&cursor);
2022 	}
2023 
2024 	/*
2025 	 * If all is ok we have to get the inode so we can adjust nlinks.
2026 	 *
2027 	 * WARNING: hammer_ip_del_directory() may have to terminate the
2028 	 * cursor to avoid a recursion.  It's ok to call hammer_done_cursor()
2029 	 * twice.
2030 	 */
2031 	if (error == 0)
2032 		error = hammer_ip_del_directory(&trans, &cursor, fdip, ip);
2033 
2034 	/*
2035 	 * XXX A deadlock here will break rename's atomicy for the purposes
2036 	 * of crash recovery.
2037 	 */
2038 	if (error == EDEADLK) {
2039 		hammer_done_cursor(&cursor);
2040 		goto retry;
2041 	}
2042 
2043 	/*
2044 	 * Cleanup and tell the kernel that the rename succeeded.
2045 	 *
2046 	 * NOTE: ip->vp, if non-NULL, cannot be directly referenced
2047 	 *	 without formally acquiring the vp since the vp might
2048 	 *	 have zero refs on it, or in the middle of a reclaim,
2049 	 *	 etc.
2050 	 */
2051         hammer_done_cursor(&cursor);
2052 	if (error == 0) {
2053 		cache_rename(ap->a_fnch, ap->a_tnch);
2054 		hammer_knote(ap->a_fdvp, NOTE_WRITE);
2055 		hammer_knote(ap->a_tdvp, NOTE_WRITE);
2056 		while (ip->vp) {
2057 			struct vnode *vp;
2058 
2059 			error = hammer_get_vnode(ip, &vp);
2060 			if (error == 0 && vp) {
2061 				vn_unlock(vp);
2062 				hammer_knote(ip->vp, NOTE_RENAME);
2063 				vrele(vp);
2064 				break;
2065 			}
2066 			kprintf("Debug: HAMMER ip/vp race2 avoided\n");
2067 		}
2068 	}
2069 
2070 failed:
2071 	hammer_done_transaction(&trans);
2072 	lwkt_reltoken(&hmp->fs_token);
2073 	return (error);
2074 }
2075 
2076 /*
2077  * hammer_vop_nrmdir { nch, dvp, cred }
2078  */
2079 static
2080 int
2081 hammer_vop_nrmdir(struct vop_nrmdir_args *ap)
2082 {
2083 	struct hammer_transaction trans;
2084 	struct hammer_inode *dip;
2085 	hammer_mount_t hmp;
2086 	int error;
2087 
2088 	dip = VTOI(ap->a_dvp);
2089 	hmp = dip->hmp;
2090 
2091 	if (hammer_nohistory(dip) == 0 &&
2092 	    (error = hammer_checkspace(hmp, HAMMER_CHKSPC_REMOVE)) != 0) {
2093 		return (error);
2094 	}
2095 
2096 	lwkt_gettoken(&hmp->fs_token);
2097 	hammer_start_transaction(&trans, hmp);
2098 	++hammer_stats_file_iopsw;
2099 	error = hammer_dounlink(&trans, ap->a_nch, ap->a_dvp, ap->a_cred, 0, 1);
2100 	hammer_done_transaction(&trans);
2101 	if (error == 0)
2102 		hammer_knote(ap->a_dvp, NOTE_WRITE | NOTE_LINK);
2103 	lwkt_reltoken(&hmp->fs_token);
2104 	return (error);
2105 }
2106 
2107 /*
2108  * hammer_vop_markatime { vp, cred }
2109  */
2110 static
2111 int
2112 hammer_vop_markatime(struct vop_markatime_args *ap)
2113 {
2114 	struct hammer_transaction trans;
2115 	struct hammer_inode *ip;
2116 	hammer_mount_t hmp;
2117 
2118 	ip = VTOI(ap->a_vp);
2119 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2120 		return (EROFS);
2121 	if (ip->flags & HAMMER_INODE_RO)
2122 		return (EROFS);
2123 	hmp = ip->hmp;
2124 	if (hmp->mp->mnt_flag & MNT_NOATIME)
2125 		return (0);
2126 	lwkt_gettoken(&hmp->fs_token);
2127 	hammer_start_transaction(&trans, hmp);
2128 	++hammer_stats_file_iopsw;
2129 
2130 	ip->ino_data.atime = trans.time;
2131 	hammer_modify_inode(&trans, ip, HAMMER_INODE_ATIME);
2132 	hammer_done_transaction(&trans);
2133 	hammer_knote(ap->a_vp, NOTE_ATTRIB);
2134 	lwkt_reltoken(&hmp->fs_token);
2135 	return (0);
2136 }
2137 
2138 /*
2139  * hammer_vop_setattr { vp, vap, cred }
2140  */
2141 static
2142 int
2143 hammer_vop_setattr(struct vop_setattr_args *ap)
2144 {
2145 	struct hammer_transaction trans;
2146 	struct hammer_inode *ip;
2147 	struct vattr *vap;
2148 	hammer_mount_t hmp;
2149 	int modflags;
2150 	int error;
2151 	int truncating;
2152 	int blksize;
2153 	int kflags;
2154 #if 0
2155 	int64_t aligned_size;
2156 #endif
2157 	u_int32_t flags;
2158 
2159 	vap = ap->a_vap;
2160 	ip = ap->a_vp->v_data;
2161 	modflags = 0;
2162 	kflags = 0;
2163 	hmp = ip->hmp;
2164 
2165 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
2166 		return(EROFS);
2167 	if (ip->flags & HAMMER_INODE_RO)
2168 		return (EROFS);
2169 	if (hammer_nohistory(ip) == 0 &&
2170 	    (error = hammer_checkspace(hmp, HAMMER_CHKSPC_REMOVE)) != 0) {
2171 		return (error);
2172 	}
2173 
2174 	lwkt_gettoken(&hmp->fs_token);
2175 	hammer_start_transaction(&trans, hmp);
2176 	++hammer_stats_file_iopsw;
2177 	error = 0;
2178 
2179 	if (vap->va_flags != VNOVAL) {
2180 		flags = ip->ino_data.uflags;
2181 		error = vop_helper_setattr_flags(&flags, vap->va_flags,
2182 					 hammer_to_unix_xid(&ip->ino_data.uid),
2183 					 ap->a_cred);
2184 		if (error == 0) {
2185 			if (ip->ino_data.uflags != flags) {
2186 				ip->ino_data.uflags = flags;
2187 				ip->ino_data.ctime = trans.time;
2188 				modflags |= HAMMER_INODE_DDIRTY;
2189 				kflags |= NOTE_ATTRIB;
2190 			}
2191 			if (ip->ino_data.uflags & (IMMUTABLE | APPEND)) {
2192 				error = 0;
2193 				goto done;
2194 			}
2195 		}
2196 		goto done;
2197 	}
2198 	if (ip->ino_data.uflags & (IMMUTABLE | APPEND)) {
2199 		error = EPERM;
2200 		goto done;
2201 	}
2202 	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
2203 		mode_t cur_mode = ip->ino_data.mode;
2204 		uid_t cur_uid = hammer_to_unix_xid(&ip->ino_data.uid);
2205 		gid_t cur_gid = hammer_to_unix_xid(&ip->ino_data.gid);
2206 		uuid_t uuid_uid;
2207 		uuid_t uuid_gid;
2208 
2209 		error = vop_helper_chown(ap->a_vp, vap->va_uid, vap->va_gid,
2210 					 ap->a_cred,
2211 					 &cur_uid, &cur_gid, &cur_mode);
2212 		if (error == 0) {
2213 			hammer_guid_to_uuid(&uuid_uid, cur_uid);
2214 			hammer_guid_to_uuid(&uuid_gid, cur_gid);
2215 			if (bcmp(&uuid_uid, &ip->ino_data.uid,
2216 				 sizeof(uuid_uid)) ||
2217 			    bcmp(&uuid_gid, &ip->ino_data.gid,
2218 				 sizeof(uuid_gid)) ||
2219 			    ip->ino_data.mode != cur_mode
2220 			) {
2221 				ip->ino_data.uid = uuid_uid;
2222 				ip->ino_data.gid = uuid_gid;
2223 				ip->ino_data.mode = cur_mode;
2224 				ip->ino_data.ctime = trans.time;
2225 				modflags |= HAMMER_INODE_DDIRTY;
2226 			}
2227 			kflags |= NOTE_ATTRIB;
2228 		}
2229 	}
2230 	while (vap->va_size != VNOVAL && ip->ino_data.size != vap->va_size) {
2231 		switch(ap->a_vp->v_type) {
2232 		case VREG:
2233 			if (vap->va_size == ip->ino_data.size)
2234 				break;
2235 
2236 			/*
2237 			 * Log the operation if in fast-fsync mode or if
2238 			 * there are unterminated redo write records present.
2239 			 *
2240 			 * The second check is needed so the recovery code
2241 			 * properly truncates write redos even if nominal
2242 			 * REDO operations is turned off due to excessive
2243 			 * writes, because the related records might be
2244 			 * destroyed and never lay down a TERM_WRITE.
2245 			 */
2246 			if ((ip->flags & HAMMER_INODE_REDO) ||
2247 			    (ip->flags & HAMMER_INODE_RDIRTY)) {
2248 				error = hammer_generate_redo(&trans, ip,
2249 							     vap->va_size,
2250 							     HAMMER_REDO_TRUNC,
2251 							     NULL, 0);
2252 			}
2253 			blksize = hammer_blocksize(vap->va_size);
2254 
2255 			/*
2256 			 * XXX break atomicy, we can deadlock the backend
2257 			 * if we do not release the lock.  Probably not a
2258 			 * big deal here.
2259 			 */
2260 			if (vap->va_size < ip->ino_data.size) {
2261 				nvtruncbuf(ap->a_vp, vap->va_size,
2262 					   blksize,
2263 					   hammer_blockoff(vap->va_size));
2264 				truncating = 1;
2265 				kflags |= NOTE_WRITE;
2266 			} else {
2267 				nvextendbuf(ap->a_vp,
2268 					    ip->ino_data.size,
2269 					    vap->va_size,
2270 					    hammer_blocksize(ip->ino_data.size),
2271 					    hammer_blocksize(vap->va_size),
2272 					    hammer_blockoff(ip->ino_data.size),
2273 					    hammer_blockoff(vap->va_size),
2274 					    0);
2275 				truncating = 0;
2276 				kflags |= NOTE_WRITE | NOTE_EXTEND;
2277 			}
2278 			ip->ino_data.size = vap->va_size;
2279 			ip->ino_data.mtime = trans.time;
2280 			/* XXX safe to use SDIRTY instead of DDIRTY here? */
2281 			modflags |= HAMMER_INODE_MTIME | HAMMER_INODE_DDIRTY;
2282 
2283 			/*
2284 			 * On-media truncation is cached in the inode until
2285 			 * the inode is synchronized.  We must immediately
2286 			 * handle any frontend records.
2287 			 */
2288 			if (truncating) {
2289 				hammer_ip_frontend_trunc(ip, vap->va_size);
2290 #ifdef DEBUG_TRUNCATE
2291 				if (HammerTruncIp == NULL)
2292 					HammerTruncIp = ip;
2293 #endif
2294 				if ((ip->flags & HAMMER_INODE_TRUNCATED) == 0) {
2295 					ip->flags |= HAMMER_INODE_TRUNCATED;
2296 					ip->trunc_off = vap->va_size;
2297 #ifdef DEBUG_TRUNCATE
2298 					if (ip == HammerTruncIp)
2299 					kprintf("truncate1 %016llx\n",
2300 						(long long)ip->trunc_off);
2301 #endif
2302 				} else if (ip->trunc_off > vap->va_size) {
2303 					ip->trunc_off = vap->va_size;
2304 #ifdef DEBUG_TRUNCATE
2305 					if (ip == HammerTruncIp)
2306 					kprintf("truncate2 %016llx\n",
2307 						(long long)ip->trunc_off);
2308 #endif
2309 				} else {
2310 #ifdef DEBUG_TRUNCATE
2311 					if (ip == HammerTruncIp)
2312 					kprintf("truncate3 %016llx (ignored)\n",
2313 						(long long)vap->va_size);
2314 #endif
2315 				}
2316 			}
2317 
2318 #if 0
2319 			/*
2320 			 * When truncating, nvtruncbuf() may have cleaned out
2321 			 * a portion of the last block on-disk in the buffer
2322 			 * cache.  We must clean out any frontend records
2323 			 * for blocks beyond the new last block.
2324 			 */
2325 			aligned_size = (vap->va_size + (blksize - 1)) &
2326 				       ~(int64_t)(blksize - 1);
2327 			if (truncating && vap->va_size < aligned_size) {
2328 				aligned_size -= blksize;
2329 				hammer_ip_frontend_trunc(ip, aligned_size);
2330 			}
2331 #endif
2332 			break;
2333 		case VDATABASE:
2334 			if ((ip->flags & HAMMER_INODE_TRUNCATED) == 0) {
2335 				ip->flags |= HAMMER_INODE_TRUNCATED;
2336 				ip->trunc_off = vap->va_size;
2337 			} else if (ip->trunc_off > vap->va_size) {
2338 				ip->trunc_off = vap->va_size;
2339 			}
2340 			hammer_ip_frontend_trunc(ip, vap->va_size);
2341 			ip->ino_data.size = vap->va_size;
2342 			ip->ino_data.mtime = trans.time;
2343 			modflags |= HAMMER_INODE_MTIME | HAMMER_INODE_DDIRTY;
2344 			kflags |= NOTE_ATTRIB;
2345 			break;
2346 		default:
2347 			error = EINVAL;
2348 			goto done;
2349 		}
2350 		break;
2351 	}
2352 	if (vap->va_atime.tv_sec != VNOVAL) {
2353 		ip->ino_data.atime = hammer_timespec_to_time(&vap->va_atime);
2354 		modflags |= HAMMER_INODE_ATIME;
2355 		kflags |= NOTE_ATTRIB;
2356 	}
2357 	if (vap->va_mtime.tv_sec != VNOVAL) {
2358 		ip->ino_data.mtime = hammer_timespec_to_time(&vap->va_mtime);
2359 		modflags |= HAMMER_INODE_MTIME;
2360 		kflags |= NOTE_ATTRIB;
2361 	}
2362 	if (vap->va_mode != (mode_t)VNOVAL) {
2363 		mode_t   cur_mode = ip->ino_data.mode;
2364 		uid_t cur_uid = hammer_to_unix_xid(&ip->ino_data.uid);
2365 		gid_t cur_gid = hammer_to_unix_xid(&ip->ino_data.gid);
2366 
2367 		error = vop_helper_chmod(ap->a_vp, vap->va_mode, ap->a_cred,
2368 					 cur_uid, cur_gid, &cur_mode);
2369 		if (error == 0 && ip->ino_data.mode != cur_mode) {
2370 			ip->ino_data.mode = cur_mode;
2371 			ip->ino_data.ctime = trans.time;
2372 			modflags |= HAMMER_INODE_DDIRTY;
2373 			kflags |= NOTE_ATTRIB;
2374 		}
2375 	}
2376 done:
2377 	if (error == 0)
2378 		hammer_modify_inode(&trans, ip, modflags);
2379 	hammer_done_transaction(&trans);
2380 	hammer_knote(ap->a_vp, kflags);
2381 	lwkt_reltoken(&hmp->fs_token);
2382 	return (error);
2383 }
2384 
2385 /*
2386  * hammer_vop_nsymlink { nch, dvp, vpp, cred, vap, target }
2387  */
2388 static
2389 int
2390 hammer_vop_nsymlink(struct vop_nsymlink_args *ap)
2391 {
2392 	struct hammer_transaction trans;
2393 	struct hammer_inode *dip;
2394 	struct hammer_inode *nip;
2395 	hammer_record_t record;
2396 	struct nchandle *nch;
2397 	hammer_mount_t hmp;
2398 	int error;
2399 	int bytes;
2400 
2401 	ap->a_vap->va_type = VLNK;
2402 
2403 	nch = ap->a_nch;
2404 	dip = VTOI(ap->a_dvp);
2405 	hmp = dip->hmp;
2406 
2407 	if (dip->flags & HAMMER_INODE_RO)
2408 		return (EROFS);
2409 	if ((error = hammer_checkspace(hmp, HAMMER_CHKSPC_CREATE)) != 0)
2410 		return (error);
2411 
2412 	/*
2413 	 * Create a transaction to cover the operations we perform.
2414 	 */
2415 	lwkt_gettoken(&hmp->fs_token);
2416 	hammer_start_transaction(&trans, hmp);
2417 	++hammer_stats_file_iopsw;
2418 
2419 	/*
2420 	 * Create a new filesystem object of the requested type.  The
2421 	 * returned inode will be referenced but not locked.
2422 	 */
2423 
2424 	error = hammer_create_inode(&trans, ap->a_vap, ap->a_cred,
2425 				    dip, nch->ncp->nc_name, nch->ncp->nc_nlen,
2426 				    NULL, &nip);
2427 	if (error) {
2428 		hammer_done_transaction(&trans);
2429 		*ap->a_vpp = NULL;
2430 		lwkt_reltoken(&hmp->fs_token);
2431 		return (error);
2432 	}
2433 
2434 	/*
2435 	 * Add a record representing the symlink.  symlink stores the link
2436 	 * as pure data, not a string, and is no \0 terminated.
2437 	 */
2438 	if (error == 0) {
2439 		bytes = strlen(ap->a_target);
2440 
2441 		if (bytes <= HAMMER_INODE_BASESYMLEN) {
2442 			bcopy(ap->a_target, nip->ino_data.ext.symlink, bytes);
2443 		} else {
2444 			record = hammer_alloc_mem_record(nip, bytes);
2445 			record->type = HAMMER_MEM_RECORD_GENERAL;
2446 
2447 			record->leaf.base.localization = nip->obj_localization +
2448 							 HAMMER_LOCALIZE_MISC;
2449 			record->leaf.base.key = HAMMER_FIXKEY_SYMLINK;
2450 			record->leaf.base.rec_type = HAMMER_RECTYPE_FIX;
2451 			record->leaf.data_len = bytes;
2452 			KKASSERT(HAMMER_SYMLINK_NAME_OFF == 0);
2453 			bcopy(ap->a_target, record->data->symlink.name, bytes);
2454 			error = hammer_ip_add_record(&trans, record);
2455 		}
2456 
2457 		/*
2458 		 * Set the file size to the length of the link.
2459 		 */
2460 		if (error == 0) {
2461 			nip->ino_data.size = bytes;
2462 			hammer_modify_inode(&trans, nip, HAMMER_INODE_DDIRTY);
2463 		}
2464 	}
2465 	if (error == 0)
2466 		error = hammer_ip_add_directory(&trans, dip, nch->ncp->nc_name,
2467 						nch->ncp->nc_nlen, nip);
2468 
2469 	/*
2470 	 * Finish up.
2471 	 */
2472 	if (error) {
2473 		hammer_rel_inode(nip, 0);
2474 		*ap->a_vpp = NULL;
2475 	} else {
2476 		error = hammer_get_vnode(nip, ap->a_vpp);
2477 		hammer_rel_inode(nip, 0);
2478 		if (error == 0) {
2479 			cache_setunresolved(ap->a_nch);
2480 			cache_setvp(ap->a_nch, *ap->a_vpp);
2481 			hammer_knote(ap->a_dvp, NOTE_WRITE);
2482 		}
2483 	}
2484 	hammer_done_transaction(&trans);
2485 	lwkt_reltoken(&hmp->fs_token);
2486 	return (error);
2487 }
2488 
2489 /*
2490  * hammer_vop_nwhiteout { nch, dvp, cred, flags }
2491  */
2492 static
2493 int
2494 hammer_vop_nwhiteout(struct vop_nwhiteout_args *ap)
2495 {
2496 	struct hammer_transaction trans;
2497 	struct hammer_inode *dip;
2498 	hammer_mount_t hmp;
2499 	int error;
2500 
2501 	dip = VTOI(ap->a_dvp);
2502 	hmp = dip->hmp;
2503 
2504 	if (hammer_nohistory(dip) == 0 &&
2505 	    (error = hammer_checkspace(hmp, HAMMER_CHKSPC_CREATE)) != 0) {
2506 		return (error);
2507 	}
2508 
2509 	lwkt_gettoken(&hmp->fs_token);
2510 	hammer_start_transaction(&trans, hmp);
2511 	++hammer_stats_file_iopsw;
2512 	error = hammer_dounlink(&trans, ap->a_nch, ap->a_dvp,
2513 				ap->a_cred, ap->a_flags, -1);
2514 	hammer_done_transaction(&trans);
2515 	lwkt_reltoken(&hmp->fs_token);
2516 
2517 	return (error);
2518 }
2519 
2520 /*
2521  * hammer_vop_ioctl { vp, command, data, fflag, cred }
2522  */
2523 static
2524 int
2525 hammer_vop_ioctl(struct vop_ioctl_args *ap)
2526 {
2527 	struct hammer_inode *ip = ap->a_vp->v_data;
2528 	hammer_mount_t hmp = ip->hmp;
2529 	int error;
2530 
2531 	++hammer_stats_file_iopsr;
2532 	lwkt_gettoken(&hmp->fs_token);
2533 	error = hammer_ioctl(ip, ap->a_command, ap->a_data,
2534 			     ap->a_fflag, ap->a_cred);
2535 	lwkt_reltoken(&hmp->fs_token);
2536 	return (error);
2537 }
2538 
2539 static
2540 int
2541 hammer_vop_mountctl(struct vop_mountctl_args *ap)
2542 {
2543 	static const struct mountctl_opt extraopt[] = {
2544 		{ HMNT_NOHISTORY, 	"nohistory" },
2545 		{ HMNT_MASTERID,	"master" },
2546 		{ 0, NULL}
2547 
2548 	};
2549 	struct hammer_mount *hmp;
2550 	struct mount *mp;
2551 	int usedbytes;
2552 	int error;
2553 
2554 	error = 0;
2555 	usedbytes = 0;
2556 	mp = ap->a_head.a_ops->head.vv_mount;
2557 	KKASSERT(mp->mnt_data != NULL);
2558 	hmp = (struct hammer_mount *)mp->mnt_data;
2559 
2560 	lwkt_gettoken(&hmp->fs_token);
2561 
2562 	switch(ap->a_op) {
2563 	case MOUNTCTL_SET_EXPORT:
2564 		if (ap->a_ctllen != sizeof(struct export_args))
2565 			error = EINVAL;
2566 		else
2567 			error = hammer_vfs_export(mp, ap->a_op,
2568 				      (const struct export_args *)ap->a_ctl);
2569 		break;
2570 	case MOUNTCTL_MOUNTFLAGS:
2571 	{
2572 		/*
2573 		 * Call standard mountctl VOP function
2574 		 * so we get user mount flags.
2575 		 */
2576 		error = vop_stdmountctl(ap);
2577 		if (error)
2578 			break;
2579 
2580 		usedbytes = *ap->a_res;
2581 
2582 		if (usedbytes > 0 && usedbytes < ap->a_buflen) {
2583 			usedbytes += vfs_flagstostr(hmp->hflags, extraopt,
2584 						    ap->a_buf,
2585 						    ap->a_buflen - usedbytes,
2586 						    &error);
2587 		}
2588 
2589 		*ap->a_res += usedbytes;
2590 		break;
2591 	}
2592 	default:
2593 		error = vop_stdmountctl(ap);
2594 		break;
2595 	}
2596 	lwkt_reltoken(&hmp->fs_token);
2597 	return(error);
2598 }
2599 
2600 /*
2601  * hammer_vop_strategy { vp, bio }
2602  *
2603  * Strategy call, used for regular file read & write only.  Note that the
2604  * bp may represent a cluster.
2605  *
2606  * To simplify operation and allow better optimizations in the future,
2607  * this code does not make any assumptions with regards to buffer alignment
2608  * or size.
2609  */
2610 static
2611 int
2612 hammer_vop_strategy(struct vop_strategy_args *ap)
2613 {
2614 	struct buf *bp;
2615 	int error;
2616 
2617 	bp = ap->a_bio->bio_buf;
2618 
2619 	switch(bp->b_cmd) {
2620 	case BUF_CMD_READ:
2621 		error = hammer_vop_strategy_read(ap);
2622 		break;
2623 	case BUF_CMD_WRITE:
2624 		error = hammer_vop_strategy_write(ap);
2625 		break;
2626 	default:
2627 		bp->b_error = error = EINVAL;
2628 		bp->b_flags |= B_ERROR;
2629 		biodone(ap->a_bio);
2630 		break;
2631 	}
2632 
2633 	/* hammer_dump_dedup_cache(((hammer_inode_t)ap->a_vp->v_data)->hmp); */
2634 
2635 	return (error);
2636 }
2637 
2638 /*
2639  * Read from a regular file.  Iterate the related records and fill in the
2640  * BIO/BUF.  Gaps are zero-filled.
2641  *
2642  * The support code in hammer_object.c should be used to deal with mixed
2643  * in-memory and on-disk records.
2644  *
2645  * NOTE: Can be called from the cluster code with an oversized buf.
2646  *
2647  * XXX atime update
2648  */
2649 static
2650 int
2651 hammer_vop_strategy_read(struct vop_strategy_args *ap)
2652 {
2653 	struct hammer_transaction trans;
2654 	struct hammer_inode *ip;
2655 	struct hammer_inode *dip;
2656 	hammer_mount_t hmp;
2657 	struct hammer_cursor cursor;
2658 	hammer_base_elm_t base;
2659 	hammer_off_t disk_offset;
2660 	struct bio *bio;
2661 	struct bio *nbio;
2662 	struct buf *bp;
2663 	int64_t rec_offset;
2664 	int64_t ran_end;
2665 	int64_t tmp64;
2666 	int error;
2667 	int boff;
2668 	int roff;
2669 	int n;
2670 	int isdedupable;
2671 
2672 	bio = ap->a_bio;
2673 	bp = bio->bio_buf;
2674 	ip = ap->a_vp->v_data;
2675 	hmp = ip->hmp;
2676 
2677 	/*
2678 	 * The zone-2 disk offset may have been set by the cluster code via
2679 	 * a BMAP operation, or else should be NOOFFSET.
2680 	 *
2681 	 * Checking the high bits for a match against zone-2 should suffice.
2682 	 *
2683 	 * In cases where a lot of data duplication is present it may be
2684 	 * more beneficial to drop through and doubule-buffer through the
2685 	 * device.
2686 	 */
2687 	nbio = push_bio(bio);
2688 	if (hammer_double_buffer == 0 &&
2689 	    (nbio->bio_offset & HAMMER_OFF_ZONE_MASK) ==
2690 	    HAMMER_ZONE_LARGE_DATA) {
2691 		lwkt_gettoken(&hmp->fs_token);
2692 		error = hammer_io_direct_read(hmp, nbio, NULL);
2693 		lwkt_reltoken(&hmp->fs_token);
2694 		return (error);
2695 	}
2696 
2697 	/*
2698 	 * Well, that sucked.  Do it the hard way.  If all the stars are
2699 	 * aligned we may still be able to issue a direct-read.
2700 	 */
2701 	lwkt_gettoken(&hmp->fs_token);
2702 	hammer_simple_transaction(&trans, hmp);
2703 	hammer_init_cursor(&trans, &cursor, &ip->cache[1], ip);
2704 
2705 	/*
2706 	 * Key range (begin and end inclusive) to scan.  Note that the key's
2707 	 * stored in the actual records represent BASE+LEN, not BASE.  The
2708 	 * first record containing bio_offset will have a key > bio_offset.
2709 	 */
2710 	cursor.key_beg.localization = ip->obj_localization +
2711 				      HAMMER_LOCALIZE_MISC;
2712 	cursor.key_beg.obj_id = ip->obj_id;
2713 	cursor.key_beg.create_tid = 0;
2714 	cursor.key_beg.delete_tid = 0;
2715 	cursor.key_beg.obj_type = 0;
2716 	cursor.key_beg.key = bio->bio_offset + 1;
2717 	cursor.asof = ip->obj_asof;
2718 	cursor.flags |= HAMMER_CURSOR_ASOF;
2719 
2720 	cursor.key_end = cursor.key_beg;
2721 	KKASSERT(ip->ino_data.obj_type == HAMMER_OBJTYPE_REGFILE);
2722 #if 0
2723 	if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE) {
2724 		cursor.key_beg.rec_type = HAMMER_RECTYPE_DB;
2725 		cursor.key_end.rec_type = HAMMER_RECTYPE_DB;
2726 		cursor.key_end.key = 0x7FFFFFFFFFFFFFFFLL;
2727 	} else
2728 #endif
2729 	{
2730 		ran_end = bio->bio_offset + bp->b_bufsize;
2731 		cursor.key_beg.rec_type = HAMMER_RECTYPE_DATA;
2732 		cursor.key_end.rec_type = HAMMER_RECTYPE_DATA;
2733 		tmp64 = ran_end + MAXPHYS + 1;	/* work-around GCC-4 bug */
2734 		if (tmp64 < ran_end)
2735 			cursor.key_end.key = 0x7FFFFFFFFFFFFFFFLL;
2736 		else
2737 			cursor.key_end.key = ran_end + MAXPHYS + 1;
2738 	}
2739 	cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
2740 
2741 	error = hammer_ip_first(&cursor);
2742 	boff = 0;
2743 
2744 	while (error == 0) {
2745 		/*
2746 		 * Get the base file offset of the record.  The key for
2747 		 * data records is (base + bytes) rather then (base).
2748 		 */
2749 		base = &cursor.leaf->base;
2750 		rec_offset = base->key - cursor.leaf->data_len;
2751 
2752 		/*
2753 		 * Calculate the gap, if any, and zero-fill it.
2754 		 *
2755 		 * n is the offset of the start of the record verses our
2756 		 * current seek offset in the bio.
2757 		 */
2758 		n = (int)(rec_offset - (bio->bio_offset + boff));
2759 		if (n > 0) {
2760 			if (n > bp->b_bufsize - boff)
2761 				n = bp->b_bufsize - boff;
2762 			bzero((char *)bp->b_data + boff, n);
2763 			boff += n;
2764 			n = 0;
2765 		}
2766 
2767 		/*
2768 		 * Calculate the data offset in the record and the number
2769 		 * of bytes we can copy.
2770 		 *
2771 		 * There are two degenerate cases.  First, boff may already
2772 		 * be at bp->b_bufsize.  Secondly, the data offset within
2773 		 * the record may exceed the record's size.
2774 		 */
2775 		roff = -n;
2776 		rec_offset += roff;
2777 		n = cursor.leaf->data_len - roff;
2778 		if (n <= 0) {
2779 			kprintf("strategy_read: bad n=%d roff=%d\n", n, roff);
2780 			n = 0;
2781 		} else if (n > bp->b_bufsize - boff) {
2782 			n = bp->b_bufsize - boff;
2783 		}
2784 
2785 		/*
2786 		 * Deal with cached truncations.  This cool bit of code
2787 		 * allows truncate()/ftruncate() to avoid having to sync
2788 		 * the file.
2789 		 *
2790 		 * If the frontend is truncated then all backend records are
2791 		 * subject to the frontend's truncation.
2792 		 *
2793 		 * If the backend is truncated then backend records on-disk
2794 		 * (but not in-memory) are subject to the backend's
2795 		 * truncation.  In-memory records owned by the backend
2796 		 * represent data written after the truncation point on the
2797 		 * backend and must not be truncated.
2798 		 *
2799 		 * Truncate operations deal with frontend buffer cache
2800 		 * buffers and frontend-owned in-memory records synchronously.
2801 		 */
2802 		if (ip->flags & HAMMER_INODE_TRUNCATED) {
2803 			if (hammer_cursor_ondisk(&cursor)/* ||
2804 			    cursor.iprec->flush_state == HAMMER_FST_FLUSH*/) {
2805 				if (ip->trunc_off <= rec_offset)
2806 					n = 0;
2807 				else if (ip->trunc_off < rec_offset + n)
2808 					n = (int)(ip->trunc_off - rec_offset);
2809 			}
2810 		}
2811 		if (ip->sync_flags & HAMMER_INODE_TRUNCATED) {
2812 			if (hammer_cursor_ondisk(&cursor)) {
2813 				if (ip->sync_trunc_off <= rec_offset)
2814 					n = 0;
2815 				else if (ip->sync_trunc_off < rec_offset + n)
2816 					n = (int)(ip->sync_trunc_off - rec_offset);
2817 			}
2818 		}
2819 
2820 		/*
2821 		 * Try to issue a direct read into our bio if possible,
2822 		 * otherwise resolve the element data into a hammer_buffer
2823 		 * and copy.
2824 		 *
2825 		 * The buffer on-disk should be zerod past any real
2826 		 * truncation point, but may not be for any synthesized
2827 		 * truncation point from above.
2828 		 */
2829 		disk_offset = cursor.leaf->data_offset + roff;
2830 		isdedupable = (boff == 0 && n == bp->b_bufsize &&
2831 			       hammer_cursor_ondisk(&cursor) &&
2832 			       ((int)disk_offset & HAMMER_BUFMASK) == 0);
2833 
2834 		if (isdedupable && hammer_double_buffer == 0) {
2835 			KKASSERT((disk_offset & HAMMER_OFF_ZONE_MASK) ==
2836 				 HAMMER_ZONE_LARGE_DATA);
2837 			nbio->bio_offset = disk_offset;
2838 			error = hammer_io_direct_read(hmp, nbio, cursor.leaf);
2839 			if (hammer_live_dedup && error == 0)
2840 				hammer_dedup_cache_add(ip, cursor.leaf);
2841 			goto done;
2842 		} else if (n) {
2843 			error = hammer_ip_resolve_data(&cursor);
2844 			if (error == 0) {
2845 				if (hammer_live_dedup && isdedupable)
2846 					hammer_dedup_cache_add(ip, cursor.leaf);
2847 				bcopy((char *)cursor.data + roff,
2848 				      (char *)bp->b_data + boff, n);
2849 			}
2850 		}
2851 		if (error)
2852 			break;
2853 
2854 		/*
2855 		 * We have to be sure that the only elements added to the
2856 		 * dedup cache are those which are already on-media.
2857 		 */
2858 		if (hammer_live_dedup && hammer_cursor_ondisk(&cursor))
2859 			hammer_dedup_cache_add(ip, cursor.leaf);
2860 
2861 		/*
2862 		 * Iterate until we have filled the request.
2863 		 */
2864 		boff += n;
2865 		if (boff == bp->b_bufsize)
2866 			break;
2867 		error = hammer_ip_next(&cursor);
2868 	}
2869 
2870 	/*
2871 	 * There may have been a gap after the last record
2872 	 */
2873 	if (error == ENOENT)
2874 		error = 0;
2875 	if (error == 0 && boff != bp->b_bufsize) {
2876 		KKASSERT(boff < bp->b_bufsize);
2877 		bzero((char *)bp->b_data + boff, bp->b_bufsize - boff);
2878 		/* boff = bp->b_bufsize; */
2879 	}
2880 	bp->b_resid = 0;
2881 	bp->b_error = error;
2882 	if (error)
2883 		bp->b_flags |= B_ERROR;
2884 	biodone(ap->a_bio);
2885 
2886 done:
2887 	/*
2888 	 * Cache the b-tree node for the last data read in cache[1].
2889 	 *
2890 	 * If we hit the file EOF then also cache the node in the
2891 	 * governing director's cache[3], it will be used to initialize
2892 	 * the inode's cache[1] for any inodes looked up via the directory.
2893 	 *
2894 	 * This doesn't reduce disk accesses since the B-Tree chain is
2895 	 * likely cached, but it does reduce cpu overhead when looking
2896 	 * up file offsets for cpdup/tar/cpio style iterations.
2897 	 */
2898 	if (cursor.node)
2899 		hammer_cache_node(&ip->cache[1], cursor.node);
2900 	if (ran_end >= ip->ino_data.size) {
2901 		dip = hammer_find_inode(&trans, ip->ino_data.parent_obj_id,
2902 					ip->obj_asof, ip->obj_localization);
2903 		if (dip) {
2904 			hammer_cache_node(&dip->cache[3], cursor.node);
2905 			hammer_rel_inode(dip, 0);
2906 		}
2907 	}
2908 	hammer_done_cursor(&cursor);
2909 	hammer_done_transaction(&trans);
2910 	lwkt_reltoken(&hmp->fs_token);
2911 	return(error);
2912 }
2913 
2914 /*
2915  * BMAP operation - used to support cluster_read() only.
2916  *
2917  * (struct vnode *vp, off_t loffset, off_t *doffsetp, int *runp, int *runb)
2918  *
2919  * This routine may return EOPNOTSUPP if the opration is not supported for
2920  * the specified offset.  The contents of the pointer arguments do not
2921  * need to be initialized in that case.
2922  *
2923  * If a disk address is available and properly aligned return 0 with
2924  * *doffsetp set to the zone-2 address, and *runp / *runb set appropriately
2925  * to the run-length relative to that offset.  Callers may assume that
2926  * *doffsetp is valid if 0 is returned, even if *runp is not sufficiently
2927  * large, so return EOPNOTSUPP if it is not sufficiently large.
2928  */
2929 static
2930 int
2931 hammer_vop_bmap(struct vop_bmap_args *ap)
2932 {
2933 	struct hammer_transaction trans;
2934 	struct hammer_inode *ip;
2935 	hammer_mount_t hmp;
2936 	struct hammer_cursor cursor;
2937 	hammer_base_elm_t base;
2938 	int64_t rec_offset;
2939 	int64_t ran_end;
2940 	int64_t tmp64;
2941 	int64_t base_offset;
2942 	int64_t base_disk_offset;
2943 	int64_t last_offset;
2944 	hammer_off_t last_disk_offset;
2945 	hammer_off_t disk_offset;
2946 	int	rec_len;
2947 	int	error;
2948 	int	blksize;
2949 
2950 	++hammer_stats_file_iopsr;
2951 	ip = ap->a_vp->v_data;
2952 	hmp = ip->hmp;
2953 
2954 	/*
2955 	 * We can only BMAP regular files.  We can't BMAP database files,
2956 	 * directories, etc.
2957 	 */
2958 	if (ip->ino_data.obj_type != HAMMER_OBJTYPE_REGFILE)
2959 		return(EOPNOTSUPP);
2960 
2961 	/*
2962 	 * bmap is typically called with runp/runb both NULL when used
2963 	 * for writing.  We do not support BMAP for writing atm.
2964 	 */
2965 	if (ap->a_cmd != BUF_CMD_READ)
2966 		return(EOPNOTSUPP);
2967 
2968 	/*
2969 	 * Scan the B-Tree to acquire blockmap addresses, then translate
2970 	 * to raw addresses.
2971 	 */
2972 	lwkt_gettoken(&hmp->fs_token);
2973 	hammer_simple_transaction(&trans, hmp);
2974 #if 0
2975 	kprintf("bmap_beg %016llx ip->cache %p\n",
2976 		(long long)ap->a_loffset, ip->cache[1]);
2977 #endif
2978 	hammer_init_cursor(&trans, &cursor, &ip->cache[1], ip);
2979 
2980 	/*
2981 	 * Key range (begin and end inclusive) to scan.  Note that the key's
2982 	 * stored in the actual records represent BASE+LEN, not BASE.  The
2983 	 * first record containing bio_offset will have a key > bio_offset.
2984 	 */
2985 	cursor.key_beg.localization = ip->obj_localization +
2986 				      HAMMER_LOCALIZE_MISC;
2987 	cursor.key_beg.obj_id = ip->obj_id;
2988 	cursor.key_beg.create_tid = 0;
2989 	cursor.key_beg.delete_tid = 0;
2990 	cursor.key_beg.obj_type = 0;
2991 	if (ap->a_runb)
2992 		cursor.key_beg.key = ap->a_loffset - MAXPHYS + 1;
2993 	else
2994 		cursor.key_beg.key = ap->a_loffset + 1;
2995 	if (cursor.key_beg.key < 0)
2996 		cursor.key_beg.key = 0;
2997 	cursor.asof = ip->obj_asof;
2998 	cursor.flags |= HAMMER_CURSOR_ASOF;
2999 
3000 	cursor.key_end = cursor.key_beg;
3001 	KKASSERT(ip->ino_data.obj_type == HAMMER_OBJTYPE_REGFILE);
3002 
3003 	ran_end = ap->a_loffset + MAXPHYS;
3004 	cursor.key_beg.rec_type = HAMMER_RECTYPE_DATA;
3005 	cursor.key_end.rec_type = HAMMER_RECTYPE_DATA;
3006 	tmp64 = ran_end + MAXPHYS + 1;	/* work-around GCC-4 bug */
3007 	if (tmp64 < ran_end)
3008 		cursor.key_end.key = 0x7FFFFFFFFFFFFFFFLL;
3009 	else
3010 		cursor.key_end.key = ran_end + MAXPHYS + 1;
3011 
3012 	cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
3013 
3014 	error = hammer_ip_first(&cursor);
3015 	base_offset = last_offset = 0;
3016 	base_disk_offset = last_disk_offset = 0;
3017 
3018 	while (error == 0) {
3019 		/*
3020 		 * Get the base file offset of the record.  The key for
3021 		 * data records is (base + bytes) rather then (base).
3022 		 *
3023 		 * NOTE: rec_offset + rec_len may exceed the end-of-file.
3024 		 * The extra bytes should be zero on-disk and the BMAP op
3025 		 * should still be ok.
3026 		 */
3027 		base = &cursor.leaf->base;
3028 		rec_offset = base->key - cursor.leaf->data_len;
3029 		rec_len    = cursor.leaf->data_len;
3030 
3031 		/*
3032 		 * Incorporate any cached truncation.
3033 		 *
3034 		 * NOTE: Modifications to rec_len based on synthesized
3035 		 * truncation points remove the guarantee that any extended
3036 		 * data on disk is zero (since the truncations may not have
3037 		 * taken place on-media yet).
3038 		 */
3039 		if (ip->flags & HAMMER_INODE_TRUNCATED) {
3040 			if (hammer_cursor_ondisk(&cursor) ||
3041 			    cursor.iprec->flush_state == HAMMER_FST_FLUSH) {
3042 				if (ip->trunc_off <= rec_offset)
3043 					rec_len = 0;
3044 				else if (ip->trunc_off < rec_offset + rec_len)
3045 					rec_len = (int)(ip->trunc_off - rec_offset);
3046 			}
3047 		}
3048 		if (ip->sync_flags & HAMMER_INODE_TRUNCATED) {
3049 			if (hammer_cursor_ondisk(&cursor)) {
3050 				if (ip->sync_trunc_off <= rec_offset)
3051 					rec_len = 0;
3052 				else if (ip->sync_trunc_off < rec_offset + rec_len)
3053 					rec_len = (int)(ip->sync_trunc_off - rec_offset);
3054 			}
3055 		}
3056 
3057 		/*
3058 		 * Accumulate information.  If we have hit a discontiguous
3059 		 * block reset base_offset unless we are already beyond the
3060 		 * requested offset.  If we are, that's it, we stop.
3061 		 */
3062 		if (error)
3063 			break;
3064 		if (hammer_cursor_ondisk(&cursor)) {
3065 			disk_offset = cursor.leaf->data_offset;
3066 			if (rec_offset != last_offset ||
3067 			    disk_offset != last_disk_offset) {
3068 				if (rec_offset > ap->a_loffset)
3069 					break;
3070 				base_offset = rec_offset;
3071 				base_disk_offset = disk_offset;
3072 			}
3073 			last_offset = rec_offset + rec_len;
3074 			last_disk_offset = disk_offset + rec_len;
3075 
3076 			if (hammer_live_dedup)
3077 				hammer_dedup_cache_add(ip, cursor.leaf);
3078 		}
3079 
3080 		error = hammer_ip_next(&cursor);
3081 	}
3082 
3083 #if 0
3084 	kprintf("BMAP %016llx:  %016llx - %016llx\n",
3085 		(long long)ap->a_loffset,
3086 		(long long)base_offset,
3087 		(long long)last_offset);
3088 	kprintf("BMAP %16s:  %016llx - %016llx\n", "",
3089 		(long long)base_disk_offset,
3090 		(long long)last_disk_offset);
3091 #endif
3092 
3093 	if (cursor.node) {
3094 		hammer_cache_node(&ip->cache[1], cursor.node);
3095 #if 0
3096 		kprintf("bmap_end2 %016llx ip->cache %p\n",
3097 			(long long)ap->a_loffset, ip->cache[1]);
3098 #endif
3099 	}
3100 	hammer_done_cursor(&cursor);
3101 	hammer_done_transaction(&trans);
3102 	lwkt_reltoken(&hmp->fs_token);
3103 
3104 	/*
3105 	 * If we couldn't find any records or the records we did find were
3106 	 * all behind the requested offset, return failure.  A forward
3107 	 * truncation can leave a hole w/ no on-disk records.
3108 	 */
3109 	if (last_offset == 0 || last_offset < ap->a_loffset)
3110 		return (EOPNOTSUPP);
3111 
3112 	/*
3113 	 * Figure out the block size at the requested offset and adjust
3114 	 * our limits so the cluster_read() does not create inappropriately
3115 	 * sized buffer cache buffers.
3116 	 */
3117 	blksize = hammer_blocksize(ap->a_loffset);
3118 	if (hammer_blocksize(base_offset) != blksize) {
3119 		base_offset = hammer_blockdemarc(base_offset, ap->a_loffset);
3120 	}
3121 	if (last_offset != ap->a_loffset &&
3122 	    hammer_blocksize(last_offset - 1) != blksize) {
3123 		last_offset = hammer_blockdemarc(ap->a_loffset,
3124 						 last_offset - 1);
3125 	}
3126 
3127 	/*
3128 	 * Returning EOPNOTSUPP simply prevents the direct-IO optimization
3129 	 * from occuring.
3130 	 */
3131 	disk_offset = base_disk_offset + (ap->a_loffset - base_offset);
3132 
3133 	if ((disk_offset & HAMMER_OFF_ZONE_MASK) != HAMMER_ZONE_LARGE_DATA) {
3134 		/*
3135 		 * Only large-data zones can be direct-IOd
3136 		 */
3137 		error = EOPNOTSUPP;
3138 	} else if ((disk_offset & HAMMER_BUFMASK) ||
3139 		   (last_offset - ap->a_loffset) < blksize) {
3140 		/*
3141 		 * doffsetp is not aligned or the forward run size does
3142 		 * not cover a whole buffer, disallow the direct I/O.
3143 		 */
3144 		error = EOPNOTSUPP;
3145 	} else {
3146 		/*
3147 		 * We're good.
3148 		 */
3149 		*ap->a_doffsetp = disk_offset;
3150 		if (ap->a_runb) {
3151 			*ap->a_runb = ap->a_loffset - base_offset;
3152 			KKASSERT(*ap->a_runb >= 0);
3153 		}
3154 		if (ap->a_runp) {
3155 			*ap->a_runp = last_offset - ap->a_loffset;
3156 			KKASSERT(*ap->a_runp >= 0);
3157 		}
3158 		error = 0;
3159 	}
3160 	return(error);
3161 }
3162 
3163 /*
3164  * Write to a regular file.   Because this is a strategy call the OS is
3165  * trying to actually get data onto the media.
3166  */
3167 static
3168 int
3169 hammer_vop_strategy_write(struct vop_strategy_args *ap)
3170 {
3171 	hammer_record_t record;
3172 	hammer_mount_t hmp;
3173 	hammer_inode_t ip;
3174 	struct bio *bio;
3175 	struct buf *bp;
3176 	int blksize;
3177 	int bytes;
3178 	int error;
3179 
3180 	bio = ap->a_bio;
3181 	bp = bio->bio_buf;
3182 	ip = ap->a_vp->v_data;
3183 	hmp = ip->hmp;
3184 
3185 	blksize = hammer_blocksize(bio->bio_offset);
3186 	KKASSERT(bp->b_bufsize == blksize);
3187 
3188 	if (ip->flags & HAMMER_INODE_RO) {
3189 		bp->b_error = EROFS;
3190 		bp->b_flags |= B_ERROR;
3191 		biodone(ap->a_bio);
3192 		return(EROFS);
3193 	}
3194 
3195 	lwkt_gettoken(&hmp->fs_token);
3196 
3197 	/*
3198 	 * Interlock with inode destruction (no in-kernel or directory
3199 	 * topology visibility).  If we queue new IO while trying to
3200 	 * destroy the inode we can deadlock the vtrunc call in
3201 	 * hammer_inode_unloadable_check().
3202 	 *
3203 	 * Besides, there's no point flushing a bp associated with an
3204 	 * inode that is being destroyed on-media and has no kernel
3205 	 * references.
3206 	 */
3207 	if ((ip->flags | ip->sync_flags) &
3208 	    (HAMMER_INODE_DELETING|HAMMER_INODE_DELETED)) {
3209 		bp->b_resid = 0;
3210 		biodone(ap->a_bio);
3211 		lwkt_reltoken(&hmp->fs_token);
3212 		return(0);
3213 	}
3214 
3215 	/*
3216 	 * Reserve space and issue a direct-write from the front-end.
3217 	 * NOTE: The direct_io code will hammer_bread/bcopy smaller
3218 	 * allocations.
3219 	 *
3220 	 * An in-memory record will be installed to reference the storage
3221 	 * until the flusher can get to it.
3222 	 *
3223 	 * Since we own the high level bio the front-end will not try to
3224 	 * do a direct-read until the write completes.
3225 	 *
3226 	 * NOTE: The only time we do not reserve a full-sized buffers
3227 	 * worth of data is if the file is small.  We do not try to
3228 	 * allocate a fragment (from the small-data zone) at the end of
3229 	 * an otherwise large file as this can lead to wildly separated
3230 	 * data.
3231 	 */
3232 	KKASSERT((bio->bio_offset & HAMMER_BUFMASK) == 0);
3233 	KKASSERT(bio->bio_offset < ip->ino_data.size);
3234 	if (bio->bio_offset || ip->ino_data.size > HAMMER_BUFSIZE / 2)
3235 		bytes = bp->b_bufsize;
3236 	else
3237 		bytes = ((int)ip->ino_data.size + 15) & ~15;
3238 
3239 	record = hammer_ip_add_bulk(ip, bio->bio_offset, bp->b_data,
3240 				    bytes, &error);
3241 
3242 	/*
3243 	 * B_VFSFLAG1 indicates that a REDO_WRITE entry was generated
3244 	 * in hammer_vop_write().  We must flag the record so the proper
3245 	 * REDO_TERM_WRITE entry is generated during the flush.
3246 	 */
3247 	if (record) {
3248 		if (bp->b_flags & B_VFSFLAG1) {
3249 			record->flags |= HAMMER_RECF_REDO;
3250 			bp->b_flags &= ~B_VFSFLAG1;
3251 		}
3252 		if (record->flags & HAMMER_RECF_DEDUPED) {
3253 			bp->b_resid = 0;
3254 			hammer_ip_replace_bulk(hmp, record);
3255 			biodone(ap->a_bio);
3256 		} else {
3257 			hammer_io_direct_write(hmp, bio, record);
3258 		}
3259 		if (ip->rsv_recs > 1 && hmp->rsv_recs > hammer_limit_recs)
3260 			hammer_flush_inode(ip, 0);
3261 	} else {
3262 		bp->b_bio2.bio_offset = NOOFFSET;
3263 		bp->b_error = error;
3264 		bp->b_flags |= B_ERROR;
3265 		biodone(ap->a_bio);
3266 	}
3267 	lwkt_reltoken(&hmp->fs_token);
3268 	return(error);
3269 }
3270 
3271 /*
3272  * dounlink - disconnect a directory entry
3273  *
3274  * XXX whiteout support not really in yet
3275  */
3276 static int
3277 hammer_dounlink(hammer_transaction_t trans, struct nchandle *nch,
3278 		struct vnode *dvp, struct ucred *cred,
3279 		int flags, int isdir)
3280 {
3281 	struct namecache *ncp;
3282 	hammer_inode_t dip;
3283 	hammer_inode_t ip;
3284 	hammer_mount_t hmp;
3285 	struct hammer_cursor cursor;
3286 	int64_t namekey;
3287 	u_int32_t max_iterations;
3288 	int nlen, error;
3289 
3290 	/*
3291 	 * Calculate the namekey and setup the key range for the scan.  This
3292 	 * works kinda like a chained hash table where the lower 32 bits
3293 	 * of the namekey synthesize the chain.
3294 	 *
3295 	 * The key range is inclusive of both key_beg and key_end.
3296 	 */
3297 	dip = VTOI(dvp);
3298 	ncp = nch->ncp;
3299 	hmp = dip->hmp;
3300 
3301 	if (dip->flags & HAMMER_INODE_RO)
3302 		return (EROFS);
3303 
3304 	namekey = hammer_directory_namekey(dip, ncp->nc_name, ncp->nc_nlen,
3305 					   &max_iterations);
3306 retry:
3307 	hammer_init_cursor(trans, &cursor, &dip->cache[1], dip);
3308 	cursor.key_beg.localization = dip->obj_localization +
3309 				      hammer_dir_localization(dip);
3310         cursor.key_beg.obj_id = dip->obj_id;
3311 	cursor.key_beg.key = namekey;
3312         cursor.key_beg.create_tid = 0;
3313         cursor.key_beg.delete_tid = 0;
3314         cursor.key_beg.rec_type = HAMMER_RECTYPE_DIRENTRY;
3315         cursor.key_beg.obj_type = 0;
3316 
3317 	cursor.key_end = cursor.key_beg;
3318 	cursor.key_end.key += max_iterations;
3319 	cursor.asof = dip->obj_asof;
3320 	cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF;
3321 
3322 	/*
3323 	 * Scan all matching records (the chain), locate the one matching
3324 	 * the requested path component.  info->last_error contains the
3325 	 * error code on search termination and could be 0, ENOENT, or
3326 	 * something else.
3327 	 *
3328 	 * The hammer_ip_*() functions merge in-memory records with on-disk
3329 	 * records for the purposes of the search.
3330 	 */
3331 	error = hammer_ip_first(&cursor);
3332 
3333 	while (error == 0) {
3334 		error = hammer_ip_resolve_data(&cursor);
3335 		if (error)
3336 			break;
3337 		nlen = cursor.leaf->data_len - HAMMER_ENTRY_NAME_OFF;
3338 		KKASSERT(nlen > 0);
3339 		if (ncp->nc_nlen == nlen &&
3340 		    bcmp(ncp->nc_name, cursor.data->entry.name, nlen) == 0) {
3341 			break;
3342 		}
3343 		error = hammer_ip_next(&cursor);
3344 	}
3345 
3346 	/*
3347 	 * If all is ok we have to get the inode so we can adjust nlinks.
3348 	 * To avoid a deadlock with the flusher we must release the inode
3349 	 * lock on the directory when acquiring the inode for the entry.
3350 	 *
3351 	 * If the target is a directory, it must be empty.
3352 	 */
3353 	if (error == 0) {
3354 		hammer_unlock(&cursor.ip->lock);
3355 		ip = hammer_get_inode(trans, dip, cursor.data->entry.obj_id,
3356 				      hmp->asof,
3357 				      cursor.data->entry.localization,
3358 				      0, &error);
3359 		hammer_lock_sh(&cursor.ip->lock);
3360 		if (error == ENOENT) {
3361 			kprintf("HAMMER: WARNING: Removing "
3362 				"dirent w/missing inode \"%s\"\n"
3363 				"\tobj_id = %016llx\n",
3364 				ncp->nc_name,
3365 				(long long)cursor.data->entry.obj_id);
3366 			error = 0;
3367 		}
3368 
3369 		/*
3370 		 * If isdir >= 0 we validate that the entry is or is not a
3371 		 * directory.  If isdir < 0 we don't care.
3372 		 */
3373 		if (error == 0 && isdir >= 0 && ip) {
3374 			if (isdir &&
3375 			    ip->ino_data.obj_type != HAMMER_OBJTYPE_DIRECTORY) {
3376 				error = ENOTDIR;
3377 			} else if (isdir == 0 &&
3378 			    ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
3379 				error = EISDIR;
3380 			}
3381 		}
3382 
3383 		/*
3384 		 * If we are trying to remove a directory the directory must
3385 		 * be empty.
3386 		 *
3387 		 * The check directory code can loop and deadlock/retry.  Our
3388 		 * own cursor's node locks must be released to avoid a 3-way
3389 		 * deadlock with the flusher if the check directory code
3390 		 * blocks.
3391 		 *
3392 		 * If any changes whatsoever have been made to the cursor
3393 		 * set EDEADLK and retry.
3394 		 *
3395 		 * WARNING: See warnings in hammer_unlock_cursor()
3396 		 *	    function.
3397 		 */
3398 		if (error == 0 && ip && ip->ino_data.obj_type ==
3399 				        HAMMER_OBJTYPE_DIRECTORY) {
3400 			hammer_unlock_cursor(&cursor);
3401 			error = hammer_ip_check_directory_empty(trans, ip);
3402 			hammer_lock_cursor(&cursor);
3403 			if (cursor.flags & HAMMER_CURSOR_RETEST) {
3404 				kprintf("HAMMER: Warning: avoided deadlock "
3405 					"on rmdir '%s'\n",
3406 					ncp->nc_name);
3407 				error = EDEADLK;
3408 			}
3409 		}
3410 
3411 		/*
3412 		 * Delete the directory entry.
3413 		 *
3414 		 * WARNING: hammer_ip_del_directory() may have to terminate
3415 		 * the cursor to avoid a deadlock.  It is ok to call
3416 		 * hammer_done_cursor() twice.
3417 		 */
3418 		if (error == 0) {
3419 			error = hammer_ip_del_directory(trans, &cursor,
3420 							dip, ip);
3421 		}
3422 		hammer_done_cursor(&cursor);
3423 		if (error == 0) {
3424 			cache_setunresolved(nch);
3425 			cache_setvp(nch, NULL);
3426 
3427 			/*
3428 			 * NOTE: ip->vp, if non-NULL, cannot be directly
3429 			 *	 referenced without formally acquiring the
3430 			 *	 vp since the vp might have zero refs on it,
3431 			 *	 or in the middle of a reclaim, etc.
3432 			 *
3433 			 * NOTE: The cache_setunresolved() can rip the vp
3434 			 *	 out from under us since the vp may not have
3435 			 *	 any refs, in which case ip->vp will be NULL
3436 			 *	 from the outset.
3437 			 */
3438 			while (ip && ip->vp) {
3439 				struct vnode *vp;
3440 
3441 				error = hammer_get_vnode(ip, &vp);
3442 				if (error == 0 && vp) {
3443 					vn_unlock(vp);
3444 					hammer_knote(ip->vp, NOTE_DELETE);
3445 					cache_inval_vp(ip->vp, CINV_DESTROY);
3446 					vrele(vp);
3447 					break;
3448 				}
3449 				kprintf("Debug: HAMMER ip/vp race1 avoided\n");
3450 			}
3451 		}
3452 		if (ip)
3453 			hammer_rel_inode(ip, 0);
3454 	} else {
3455 		hammer_done_cursor(&cursor);
3456 	}
3457 	if (error == EDEADLK)
3458 		goto retry;
3459 
3460 	return (error);
3461 }
3462 
3463 /************************************************************************
3464  *			    FIFO AND SPECFS OPS				*
3465  ************************************************************************
3466  *
3467  */
3468 static int
3469 hammer_vop_fifoclose (struct vop_close_args *ap)
3470 {
3471 	/* XXX update itimes */
3472 	return (VOCALL(&fifo_vnode_vops, &ap->a_head));
3473 }
3474 
3475 static int
3476 hammer_vop_fiforead (struct vop_read_args *ap)
3477 {
3478 	int error;
3479 
3480 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
3481 	/* XXX update access time */
3482 	return (error);
3483 }
3484 
3485 static int
3486 hammer_vop_fifowrite (struct vop_write_args *ap)
3487 {
3488 	int error;
3489 
3490 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
3491 	/* XXX update access time */
3492 	return (error);
3493 }
3494 
3495 static
3496 int
3497 hammer_vop_fifokqfilter(struct vop_kqfilter_args *ap)
3498 {
3499 	int error;
3500 
3501 	error = VOCALL(&fifo_vnode_vops, &ap->a_head);
3502 	if (error)
3503 		error = hammer_vop_kqfilter(ap);
3504 	return(error);
3505 }
3506 
3507 /************************************************************************
3508  *			    KQFILTER OPS				*
3509  ************************************************************************
3510  *
3511  */
3512 static void filt_hammerdetach(struct knote *kn);
3513 static int filt_hammerread(struct knote *kn, long hint);
3514 static int filt_hammerwrite(struct knote *kn, long hint);
3515 static int filt_hammervnode(struct knote *kn, long hint);
3516 
3517 static struct filterops hammerread_filtops =
3518 	{ FILTEROP_ISFD, NULL, filt_hammerdetach, filt_hammerread };
3519 static struct filterops hammerwrite_filtops =
3520 	{ FILTEROP_ISFD, NULL, filt_hammerdetach, filt_hammerwrite };
3521 static struct filterops hammervnode_filtops =
3522 	{ FILTEROP_ISFD, NULL, filt_hammerdetach, filt_hammervnode };
3523 
3524 static
3525 int
3526 hammer_vop_kqfilter(struct vop_kqfilter_args *ap)
3527 {
3528 	struct vnode *vp = ap->a_vp;
3529 	struct knote *kn = ap->a_kn;
3530 
3531 	switch (kn->kn_filter) {
3532 	case EVFILT_READ:
3533 		kn->kn_fop = &hammerread_filtops;
3534 		break;
3535 	case EVFILT_WRITE:
3536 		kn->kn_fop = &hammerwrite_filtops;
3537 		break;
3538 	case EVFILT_VNODE:
3539 		kn->kn_fop = &hammervnode_filtops;
3540 		break;
3541 	default:
3542 		return (EOPNOTSUPP);
3543 	}
3544 
3545 	kn->kn_hook = (caddr_t)vp;
3546 
3547 	knote_insert(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
3548 
3549 	return(0);
3550 }
3551 
3552 static void
3553 filt_hammerdetach(struct knote *kn)
3554 {
3555 	struct vnode *vp = (void *)kn->kn_hook;
3556 
3557 	knote_remove(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
3558 }
3559 
3560 static int
3561 filt_hammerread(struct knote *kn, long hint)
3562 {
3563 	struct vnode *vp = (void *)kn->kn_hook;
3564 	hammer_inode_t ip = VTOI(vp);
3565 	hammer_mount_t hmp = ip->hmp;
3566 	off_t off;
3567 
3568 	if (hint == NOTE_REVOKE) {
3569 		kn->kn_flags |= (EV_EOF | EV_ONESHOT);
3570 		return(1);
3571 	}
3572 	lwkt_gettoken(&hmp->fs_token);	/* XXX use per-ip-token */
3573 	off = ip->ino_data.size - kn->kn_fp->f_offset;
3574 	kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
3575 	lwkt_reltoken(&hmp->fs_token);
3576 	if (kn->kn_sfflags & NOTE_OLDAPI)
3577 		return(1);
3578 	return (kn->kn_data != 0);
3579 }
3580 
3581 static int
3582 filt_hammerwrite(struct knote *kn, long hint)
3583 {
3584 	if (hint == NOTE_REVOKE)
3585 		kn->kn_flags |= (EV_EOF | EV_ONESHOT);
3586 	kn->kn_data = 0;
3587 	return (1);
3588 }
3589 
3590 static int
3591 filt_hammervnode(struct knote *kn, long hint)
3592 {
3593 	if (kn->kn_sfflags & hint)
3594 		kn->kn_fflags |= hint;
3595 	if (hint == NOTE_REVOKE) {
3596 		kn->kn_flags |= EV_EOF;
3597 		return (1);
3598 	}
3599 	return (kn->kn_fflags != 0);
3600 }
3601 
3602