c5354e8771f55e5e576d66d4cd34e15bb97538b4
[dragonfly.git] / sys / vfs / hammer / hammer_vfsops.c
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_vfsops.c,v 1.74 2008/11/13 02:18:43 dillon Exp $
35  */
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/vnode.h>
41 #include <sys/mount.h>
42 #include <sys/malloc.h>
43 #include <sys/nlookup.h>
44 #include <sys/fcntl.h>
45 #include <sys/sysctl.h>
46 #include <sys/buf.h>
47 #include <sys/buf2.h>
48 #include "hammer.h"
49
50 /*
51  * NOTE!  Global statistics may not be MPSAFE so HAMMER never uses them
52  *        in conditionals.
53  */
54 int hammer_supported_version = HAMMER_VOL_VERSION_DEFAULT;
55 int hammer_debug_io;
56 int hammer_debug_general;
57 int hammer_debug_debug = 1;             /* medium-error panics */ 
58 int hammer_debug_inode;
59 int hammer_debug_locks;
60 int hammer_debug_btree;
61 int hammer_debug_tid;
62 int hammer_debug_recover;               /* -1 will disable, +1 will force */
63 int hammer_debug_recover_faults;
64 int hammer_debug_critical;              /* non-zero enter debugger on error */
65 int hammer_cluster_enable = 1;          /* enable read clustering by default */
66 int hammer_count_fsyncs;
67 int hammer_count_inodes;
68 int hammer_count_iqueued;
69 int hammer_count_reclaiming;
70 int hammer_count_records;
71 int hammer_count_record_datas;
72 int hammer_count_volumes;
73 int hammer_count_buffers;
74 int hammer_count_nodes;
75 int64_t hammer_count_extra_space_used;
76 int64_t hammer_stats_btree_lookups;
77 int64_t hammer_stats_btree_searches;
78 int64_t hammer_stats_btree_inserts;
79 int64_t hammer_stats_btree_deletes;
80 int64_t hammer_stats_btree_elements;
81 int64_t hammer_stats_btree_splits;
82 int64_t hammer_stats_btree_iterations;
83 int64_t hammer_stats_btree_root_iterations;
84 int64_t hammer_stats_record_iterations;
85
86 int64_t hammer_stats_file_read;
87 int64_t hammer_stats_file_write;
88 int64_t hammer_stats_file_iopsr;
89 int64_t hammer_stats_file_iopsw;
90 int64_t hammer_stats_disk_read;
91 int64_t hammer_stats_disk_write;
92 int64_t hammer_stats_inode_flushes;
93 int64_t hammer_stats_commits;
94 int64_t hammer_stats_undo;
95 int64_t hammer_stats_redo;
96
97 int hammer_count_dirtybufspace;         /* global */
98 int hammer_count_refedbufs;             /* global */
99 int hammer_count_reservations;
100 int hammer_count_io_running_read;
101 int hammer_count_io_running_write;
102 int hammer_count_io_locked;
103 int hammer_limit_dirtybufspace;         /* per-mount */
104 int hammer_limit_running_io;            /* per-mount */
105 int hammer_limit_recs;                  /* as a whole XXX */
106 int hammer_limit_inode_recs = 1024;     /* per inode */
107 int hammer_limit_reclaim = HAMMER_RECLAIM_WAIT;
108 int hammer_limit_redo = 4096 * 1024;    /* per inode */
109 int hammer_autoflush = 2000;            /* auto flush */
110 int hammer_bio_count;
111 int hammer_verify_zone;
112 int hammer_verify_data = 1;
113 int hammer_write_mode;
114 int hammer_yield_check = 16;
115 int hammer_fsync_mode = 3;
116 int64_t hammer_contention_count;
117 int64_t hammer_zone_limit;
118
119 SYSCTL_NODE(_vfs, OID_AUTO, hammer, CTLFLAG_RW, 0, "HAMMER filesystem");
120 SYSCTL_INT(_vfs_hammer, OID_AUTO, supported_version, CTLFLAG_RD,
121            &hammer_supported_version, 0, "");
122 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_general, CTLFLAG_RW,
123            &hammer_debug_general, 0, "");
124 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_io, CTLFLAG_RW,
125            &hammer_debug_io, 0, "");
126 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_debug, CTLFLAG_RW,
127            &hammer_debug_debug, 0, "");
128 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_inode, CTLFLAG_RW,
129            &hammer_debug_inode, 0, "");
130 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_locks, CTLFLAG_RW,
131            &hammer_debug_locks, 0, "");
132 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_btree, CTLFLAG_RW,
133            &hammer_debug_btree, 0, "");
134 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_tid, CTLFLAG_RW,
135            &hammer_debug_tid, 0, "");
136 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_recover, CTLFLAG_RW,
137            &hammer_debug_recover, 0, "");
138 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_recover_faults, CTLFLAG_RW,
139            &hammer_debug_recover_faults, 0, "");
140 SYSCTL_INT(_vfs_hammer, OID_AUTO, debug_critical, CTLFLAG_RW,
141            &hammer_debug_critical, 0, "");
142 SYSCTL_INT(_vfs_hammer, OID_AUTO, cluster_enable, CTLFLAG_RW,
143            &hammer_cluster_enable, 0, "");
144
145 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_dirtybufspace, CTLFLAG_RW,
146            &hammer_limit_dirtybufspace, 0, "");
147 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_running_io, CTLFLAG_RW,
148            &hammer_limit_running_io, 0, "");
149 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_recs, CTLFLAG_RW,
150            &hammer_limit_recs, 0, "");
151 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_inode_recs, CTLFLAG_RW,
152            &hammer_limit_inode_recs, 0, "");
153 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_reclaim, CTLFLAG_RW,
154            &hammer_limit_reclaim, 0, "");
155 SYSCTL_INT(_vfs_hammer, OID_AUTO, limit_redo, CTLFLAG_RW,
156            &hammer_limit_redo, 0, "");
157
158 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_fsyncs, CTLFLAG_RD,
159            &hammer_count_fsyncs, 0, "");
160 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_inodes, CTLFLAG_RD,
161            &hammer_count_inodes, 0, "");
162 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_iqueued, CTLFLAG_RD,
163            &hammer_count_iqueued, 0, "");
164 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_reclaiming, CTLFLAG_RD,
165            &hammer_count_reclaiming, 0, "");
166 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_records, CTLFLAG_RD,
167            &hammer_count_records, 0, "");
168 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_record_datas, CTLFLAG_RD,
169            &hammer_count_record_datas, 0, "");
170 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_volumes, CTLFLAG_RD,
171            &hammer_count_volumes, 0, "");
172 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_buffers, CTLFLAG_RD,
173            &hammer_count_buffers, 0, "");
174 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_nodes, CTLFLAG_RD,
175            &hammer_count_nodes, 0, "");
176 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, count_extra_space_used, CTLFLAG_RD,
177            &hammer_count_extra_space_used, 0, "");
178
179 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_searches, CTLFLAG_RD,
180            &hammer_stats_btree_searches, 0, "");
181 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_lookups, CTLFLAG_RD,
182            &hammer_stats_btree_lookups, 0, "");
183 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_inserts, CTLFLAG_RD,
184            &hammer_stats_btree_inserts, 0, "");
185 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_deletes, CTLFLAG_RD,
186            &hammer_stats_btree_deletes, 0, "");
187 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_elements, CTLFLAG_RD,
188            &hammer_stats_btree_elements, 0, "");
189 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_splits, CTLFLAG_RD,
190            &hammer_stats_btree_splits, 0, "");
191 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_iterations, CTLFLAG_RD,
192            &hammer_stats_btree_iterations, 0, "");
193 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_btree_root_iterations, CTLFLAG_RD,
194            &hammer_stats_btree_root_iterations, 0, "");
195 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_record_iterations, CTLFLAG_RD,
196            &hammer_stats_record_iterations, 0, "");
197
198 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_file_read, CTLFLAG_RD,
199            &hammer_stats_file_read, 0, "");
200 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_file_write, CTLFLAG_RD,
201            &hammer_stats_file_write, 0, "");
202 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_file_iopsr, CTLFLAG_RD,
203            &hammer_stats_file_iopsr, 0, "");
204 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_file_iopsw, CTLFLAG_RD,
205            &hammer_stats_file_iopsw, 0, "");
206 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_disk_read, CTLFLAG_RD,
207            &hammer_stats_disk_read, 0, "");
208 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_disk_write, CTLFLAG_RD,
209            &hammer_stats_disk_write, 0, "");
210 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_inode_flushes, CTLFLAG_RD,
211            &hammer_stats_inode_flushes, 0, "");
212 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_commits, CTLFLAG_RD,
213            &hammer_stats_commits, 0, "");
214 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_undo, CTLFLAG_RD,
215            &hammer_stats_undo, 0, "");
216 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, stats_redo, CTLFLAG_RD,
217            &hammer_stats_redo, 0, "");
218
219 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_dirtybufspace, CTLFLAG_RD,
220            &hammer_count_dirtybufspace, 0, "");
221 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_refedbufs, CTLFLAG_RD,
222            &hammer_count_refedbufs, 0, "");
223 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_reservations, CTLFLAG_RD,
224            &hammer_count_reservations, 0, "");
225 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_io_running_read, CTLFLAG_RD,
226            &hammer_count_io_running_read, 0, "");
227 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_io_locked, CTLFLAG_RD,
228            &hammer_count_io_locked, 0, "");
229 SYSCTL_INT(_vfs_hammer, OID_AUTO, count_io_running_write, CTLFLAG_RD,
230            &hammer_count_io_running_write, 0, "");
231 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, zone_limit, CTLFLAG_RW,
232            &hammer_zone_limit, 0, "");
233 SYSCTL_QUAD(_vfs_hammer, OID_AUTO, contention_count, CTLFLAG_RW,
234            &hammer_contention_count, 0, "");
235 SYSCTL_INT(_vfs_hammer, OID_AUTO, autoflush, CTLFLAG_RW,
236            &hammer_autoflush, 0, "");
237 SYSCTL_INT(_vfs_hammer, OID_AUTO, verify_zone, CTLFLAG_RW,
238            &hammer_verify_zone, 0, "");
239 SYSCTL_INT(_vfs_hammer, OID_AUTO, verify_data, CTLFLAG_RW,
240            &hammer_verify_data, 0, "");
241 SYSCTL_INT(_vfs_hammer, OID_AUTO, write_mode, CTLFLAG_RW,
242            &hammer_write_mode, 0, "");
243 SYSCTL_INT(_vfs_hammer, OID_AUTO, yield_check, CTLFLAG_RW,
244            &hammer_yield_check, 0, "");
245 SYSCTL_INT(_vfs_hammer, OID_AUTO, fsync_mode, CTLFLAG_RW,
246            &hammer_fsync_mode, 0, "");
247
248 KTR_INFO_MASTER(hammer);
249
250 /*
251  * VFS ABI
252  */
253 static void     hammer_free_hmp(struct mount *mp);
254
255 static int      hammer_vfs_mount(struct mount *mp, char *path, caddr_t data,
256                                 struct ucred *cred);
257 static int      hammer_vfs_unmount(struct mount *mp, int mntflags);
258 static int      hammer_vfs_root(struct mount *mp, struct vnode **vpp);
259 static int      hammer_vfs_statfs(struct mount *mp, struct statfs *sbp,
260                                 struct ucred *cred);
261 static int      hammer_vfs_statvfs(struct mount *mp, struct statvfs *sbp,
262                                 struct ucred *cred);
263 static int      hammer_vfs_sync(struct mount *mp, int waitfor);
264 static int      hammer_vfs_vget(struct mount *mp, struct vnode *dvp,
265                                 ino_t ino, struct vnode **vpp);
266 static int      hammer_vfs_init(struct vfsconf *conf);
267 static int      hammer_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
268                                 struct fid *fhp, struct vnode **vpp);
269 static int      hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp);
270 static int      hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
271                                 int *exflagsp, struct ucred **credanonp);
272
273
274 static struct vfsops hammer_vfsops = {
275         .vfs_mount      = hammer_vfs_mount,
276         .vfs_unmount    = hammer_vfs_unmount,
277         .vfs_root       = hammer_vfs_root,
278         .vfs_statfs     = hammer_vfs_statfs,
279         .vfs_statvfs    = hammer_vfs_statvfs,
280         .vfs_sync       = hammer_vfs_sync,
281         .vfs_vget       = hammer_vfs_vget,
282         .vfs_init       = hammer_vfs_init,
283         .vfs_vptofh     = hammer_vfs_vptofh,
284         .vfs_fhtovp     = hammer_vfs_fhtovp,
285         .vfs_checkexp   = hammer_vfs_checkexp
286 };
287
288 MALLOC_DEFINE(M_HAMMER, "HAMMER-mount", "");
289
290 VFS_SET(hammer_vfsops, hammer, 0);
291 MODULE_VERSION(hammer, 1);
292
293 static int
294 hammer_vfs_init(struct vfsconf *conf)
295 {
296         int n;
297
298         if (hammer_limit_recs == 0) {
299                 hammer_limit_recs = nbuf * 25;
300                 n = kmalloc_limit(M_HAMMER) / 512;
301                 if (hammer_limit_recs > n)
302                         hammer_limit_recs = n;
303         }
304         if (hammer_limit_dirtybufspace == 0) {
305                 hammer_limit_dirtybufspace = hidirtybufspace / 2;
306                 if (hammer_limit_dirtybufspace < 100)
307                         hammer_limit_dirtybufspace = 100;
308         }
309
310         /*
311          * Set reasonable limits to maintain an I/O pipeline.  This is
312          * used by the flush code which explicitly initiates I/O, and
313          * is per-mount.
314          *
315          * The system-driven buffer cache uses vfs.lorunningspace and
316          * vfs.hirunningspace globally.
317          */
318         if (hammer_limit_running_io == 0)
319                 hammer_limit_running_io = hammer_limit_dirtybufspace;
320         if (hammer_limit_running_io > 10 * 1024 * 1024)
321                 hammer_limit_running_io = 10 * 1024 * 1024;
322         return(0);
323 }
324
325 static int
326 hammer_vfs_mount(struct mount *mp, char *mntpt, caddr_t data,
327                  struct ucred *cred)
328 {
329         struct hammer_mount_info info;
330         hammer_mount_t hmp;
331         hammer_volume_t rootvol;
332         struct vnode *rootvp;
333         struct vnode *devvp = NULL;
334         const char *upath;      /* volume name in userspace */
335         char *path;             /* volume name in system space */
336         int error;
337         int i;
338         int master_id;
339         char *next_volume_ptr = NULL;
340
341         /*
342          * Accept hammer_mount_info.  mntpt is NULL for root mounts at boot.
343          */
344         if (mntpt == NULL) {
345                 bzero(&info, sizeof(info));
346                 info.asof = 0;
347                 info.hflags = 0;
348                 info.nvolumes = 1;
349
350                 next_volume_ptr = mp->mnt_stat.f_mntfromname;
351
352                 /* Count number of volumes separated by ':' */
353                 for (char *p = next_volume_ptr; *p != '\0'; ++p) {
354                         if (*p == ':') {
355                                 ++info.nvolumes;
356                         }
357                 }
358
359                 mp->mnt_flag &= ~MNT_RDONLY; /* mount R/W */
360         } else {
361                 if ((error = copyin(data, &info, sizeof(info))) != 0)
362                         return (error);
363         }
364
365         /*
366          * updating or new mount
367          */
368         if (mp->mnt_flag & MNT_UPDATE) {
369                 hmp = (void *)mp->mnt_data;
370                 KKASSERT(hmp != NULL);
371         } else {
372                 if (info.nvolumes <= 0 || info.nvolumes >= 32768)
373                         return (EINVAL);
374                 hmp = NULL;
375         }
376
377         /*
378          * master-id validation.  The master id may not be changed by a
379          * mount update.
380          */
381         if (info.hflags & HMNT_MASTERID) {
382                 if (hmp && hmp->master_id != info.master_id) {
383                         kprintf("hammer: cannot change master id "
384                                 "with mount update\n");
385                         return(EINVAL);
386                 }
387                 master_id = info.master_id;
388                 if (master_id < -1 || master_id >= HAMMER_MAX_MASTERS)
389                         return (EINVAL);
390         } else {
391                 if (hmp)
392                         master_id = hmp->master_id;
393                 else
394                         master_id = 0;
395         }
396
397         /*
398          * Interal mount data structure
399          */
400         if (hmp == NULL) {
401                 hmp = kmalloc(sizeof(*hmp), M_HAMMER, M_WAITOK | M_ZERO);
402                 mp->mnt_data = (qaddr_t)hmp;
403                 hmp->mp = mp;
404                 /*TAILQ_INIT(&hmp->recycle_list);*/
405
406                 /*
407                  * Make sure kmalloc type limits are set appropriately.
408                  *
409                  * Our inode kmalloc group is sized based on maxvnodes
410                  * (controlled by the system, not us).
411                  */
412                 kmalloc_create(&hmp->m_misc, "HAMMER-others");
413                 kmalloc_create(&hmp->m_inodes, "HAMMER-inodes");
414
415                 kmalloc_raise_limit(hmp->m_inodes, 0);  /* unlimited */
416
417                 hmp->root_btree_beg.localization = 0x00000000U;
418                 hmp->root_btree_beg.obj_id = -0x8000000000000000LL;
419                 hmp->root_btree_beg.key = -0x8000000000000000LL;
420                 hmp->root_btree_beg.create_tid = 1;
421                 hmp->root_btree_beg.delete_tid = 1;
422                 hmp->root_btree_beg.rec_type = 0;
423                 hmp->root_btree_beg.obj_type = 0;
424
425                 hmp->root_btree_end.localization = 0xFFFFFFFFU;
426                 hmp->root_btree_end.obj_id = 0x7FFFFFFFFFFFFFFFLL;
427                 hmp->root_btree_end.key = 0x7FFFFFFFFFFFFFFFLL;
428                 hmp->root_btree_end.create_tid = 0xFFFFFFFFFFFFFFFFULL;
429                 hmp->root_btree_end.delete_tid = 0;   /* special case */
430                 hmp->root_btree_end.rec_type = 0xFFFFU;
431                 hmp->root_btree_end.obj_type = 0;
432
433                 hmp->krate.freq = 1;    /* maximum reporting rate (hz) */
434                 hmp->krate.count = -16; /* initial burst */
435
436                 hmp->sync_lock.refs = 1;
437                 hmp->free_lock.refs = 1;
438                 hmp->undo_lock.refs = 1;
439                 hmp->blkmap_lock.refs = 1;
440                 hmp->snapshot_lock.refs = 1;
441                 hmp->volume_lock.refs = 1;
442
443                 TAILQ_INIT(&hmp->delay_list);
444                 TAILQ_INIT(&hmp->flush_group_list);
445                 TAILQ_INIT(&hmp->objid_cache_list);
446                 TAILQ_INIT(&hmp->undo_lru_list);
447                 TAILQ_INIT(&hmp->reclaim_list);
448         }
449         hmp->hflags &= ~HMNT_USERFLAGS;
450         hmp->hflags |= info.hflags & HMNT_USERFLAGS;
451
452         hmp->master_id = master_id;
453
454         if (info.asof) {
455                 mp->mnt_flag |= MNT_RDONLY;
456                 hmp->asof = info.asof;
457         } else {
458                 hmp->asof = HAMMER_MAX_TID;
459         }
460
461         hmp->volume_to_remove = -1;
462
463         /*
464          * Re-open read-write if originally read-only, or vise-versa.
465          *
466          * When going from read-only to read-write execute the stage2
467          * recovery if it has not already been run.
468          */
469         if (mp->mnt_flag & MNT_UPDATE) {
470                 error = 0;
471                 if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
472                         kprintf("HAMMER read-only -> read-write\n");
473                         hmp->ronly = 0;
474                         RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
475                                 hammer_adjust_volume_mode, NULL);
476                         rootvol = hammer_get_root_volume(hmp, &error);
477                         if (rootvol) {
478                                 hammer_recover_flush_buffers(hmp, rootvol, 1);
479                                 error = hammer_recover_stage2(hmp, rootvol);
480                                 bcopy(rootvol->ondisk->vol0_blockmap,
481                                       hmp->blockmap,
482                                       sizeof(hmp->blockmap));
483                                 hammer_rel_volume(rootvol, 0);
484                         }
485                         RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
486                                 hammer_reload_inode, NULL);
487                         /* kernel clears MNT_RDONLY */
488                 } else if (hmp->ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
489                         kprintf("HAMMER read-write -> read-only\n");
490                         hmp->ronly = 1; /* messy */
491                         RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
492                                 hammer_reload_inode, NULL);
493                         hmp->ronly = 0;
494                         hammer_flusher_sync(hmp);
495                         hammer_flusher_sync(hmp);
496                         hammer_flusher_sync(hmp);
497                         hmp->ronly = 1;
498                         RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
499                                 hammer_adjust_volume_mode, NULL);
500                 }
501                 return(error);
502         }
503
504         RB_INIT(&hmp->rb_vols_root);
505         RB_INIT(&hmp->rb_inos_root);
506         RB_INIT(&hmp->rb_redo_root);
507         RB_INIT(&hmp->rb_nods_root);
508         RB_INIT(&hmp->rb_undo_root);
509         RB_INIT(&hmp->rb_resv_root);
510         RB_INIT(&hmp->rb_bufs_root);
511         RB_INIT(&hmp->rb_pfsm_root);
512
513         hmp->ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
514
515         TAILQ_INIT(&hmp->volu_list);
516         TAILQ_INIT(&hmp->undo_list);
517         TAILQ_INIT(&hmp->data_list);
518         TAILQ_INIT(&hmp->meta_list);
519         TAILQ_INIT(&hmp->lose_list);
520         TAILQ_INIT(&hmp->iorun_list);
521
522         /*
523          * Load volumes
524          */
525         path = objcache_get(namei_oc, M_WAITOK);
526         hmp->nvolumes = -1;
527         for (i = 0; i < info.nvolumes; ++i) {
528                 if (mntpt == NULL) {
529                         /*
530                          * Root mount.
531                          */
532                         KKASSERT(next_volume_ptr != NULL);
533                         strcpy(path, "");
534                         if (*next_volume_ptr != '/') {
535                                 /* relative path */
536                                 strcpy(path, "/dev/");
537                         }
538                         int k;
539                         for (k = strlen(path); k < MAXPATHLEN-1; ++k) {
540                                 if (*next_volume_ptr == '\0') {
541                                         break;
542                                 } else if (*next_volume_ptr == ':') {
543                                         ++next_volume_ptr;
544                                         break;
545                                 } else {
546                                         path[k] = *next_volume_ptr;
547                                         ++next_volume_ptr;
548                                 }
549                         }
550                         path[k] = '\0';
551
552                         error = 0;
553                         cdev_t dev = kgetdiskbyname(path);
554                         error = bdevvp(dev, &devvp);
555                         if (error) {
556                                 kprintf("hammer_mountroot: can't find devvp\n");
557                         }
558                 } else {
559                         error = copyin(&info.volumes[i], &upath,
560                                        sizeof(char *));
561                         if (error == 0)
562                                 error = copyinstr(upath, path,
563                                                   MAXPATHLEN, NULL);
564                 }
565                 if (error == 0)
566                         error = hammer_install_volume(hmp, path, devvp);
567                 if (error)
568                         break;
569         }
570         objcache_put(namei_oc, path);
571
572         /*
573          * Make sure we found a root volume
574          */
575         if (error == 0 && hmp->rootvol == NULL) {
576                 kprintf("hammer_mount: No root volume found!\n");
577                 error = EINVAL;
578         }
579
580         /*
581          * Check that all required volumes are available
582          */
583         if (error == 0 && hammer_mountcheck_volumes(hmp)) {
584                 kprintf("hammer_mount: Missing volumes, cannot mount!\n");
585                 error = EINVAL;
586         }
587
588         if (error) {
589                 hammer_free_hmp(mp);
590                 return (error);
591         }
592
593         /*
594          * No errors, setup enough of the mount point so we can lookup the
595          * root vnode.
596          */
597         mp->mnt_iosize_max = MAXPHYS;
598         mp->mnt_kern_flag |= MNTK_FSMID;
599
600         /*
601          * MPSAFE code.  Note that VOPs and VFSops which are not MPSAFE
602          * will acquire a per-mount token prior to entry and release it
603          * on return, so even if we do not specify it we no longer get
604          * the BGL regardlless of how we are flagged.
605          */
606         mp->mnt_kern_flag |= MNTK_RD_MPSAFE | MNTK_GA_MPSAFE |
607                              MNTK_IN_MPSAFE;
608
609         /* 
610          * note: f_iosize is used by vnode_pager_haspage() when constructing
611          * its VOP_BMAP call.
612          */
613         mp->mnt_stat.f_iosize = HAMMER_BUFSIZE;
614         mp->mnt_stat.f_bsize = HAMMER_BUFSIZE;
615
616         mp->mnt_vstat.f_frsize = HAMMER_BUFSIZE;
617         mp->mnt_vstat.f_bsize = HAMMER_BUFSIZE;
618
619         mp->mnt_maxsymlinklen = 255;
620         mp->mnt_flag |= MNT_LOCAL;
621
622         vfs_add_vnodeops(mp, &hammer_vnode_vops, &mp->mnt_vn_norm_ops);
623         vfs_add_vnodeops(mp, &hammer_spec_vops, &mp->mnt_vn_spec_ops);
624         vfs_add_vnodeops(mp, &hammer_fifo_vops, &mp->mnt_vn_fifo_ops);
625
626         /*
627          * The root volume's ondisk pointer is only valid if we hold a
628          * reference to it.
629          */
630         rootvol = hammer_get_root_volume(hmp, &error);
631         if (error)
632                 goto failed;
633
634         /*
635          * Perform any necessary UNDO operations.  The recovery code does
636          * call hammer_undo_lookup() so we have to pre-cache the blockmap,
637          * and then re-copy it again after recovery is complete.
638          *
639          * If this is a read-only mount the UNDO information is retained
640          * in memory in the form of dirty buffer cache buffers, and not
641          * written back to the media.
642          */
643         bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
644               sizeof(hmp->blockmap));
645
646         /*
647          * Check filesystem version
648          */
649         hmp->version = rootvol->ondisk->vol_version;
650         if (hmp->version < HAMMER_VOL_VERSION_MIN ||
651             hmp->version > HAMMER_VOL_VERSION_MAX) {
652                 kprintf("HAMMER: mount unsupported fs version %d\n",
653                         hmp->version);
654                 error = ERANGE;
655                 goto done;
656         }
657
658         /*
659          * The undo_rec_limit limits the size of flush groups to avoid
660          * blowing out the UNDO FIFO.  This calculation is typically in
661          * the tens of thousands and is designed primarily when small
662          * HAMMER filesystems are created.
663          */
664         hmp->undo_rec_limit = hammer_undo_max(hmp) / 8192 + 100;
665         if (hammer_debug_general & 0x0001)
666                 kprintf("HAMMER: undo_rec_limit %d\n", hmp->undo_rec_limit);
667
668         /*
669          * NOTE: Recover stage1 not only handles meta-data recovery, it
670          *       also sets hmp->undo_seqno for HAMMER VERSION 4+ filesystems.
671          */
672         error = hammer_recover_stage1(hmp, rootvol);
673         if (error) {
674                 kprintf("Failed to recover HAMMER filesystem on mount\n");
675                 goto done;
676         }
677
678         /*
679          * Finish setup now that we have a good root volume.
680          *
681          * The top 16 bits of fsid.val[1] is a pfs id.
682          */
683         ksnprintf(mp->mnt_stat.f_mntfromname,
684                   sizeof(mp->mnt_stat.f_mntfromname), "%s",
685                   rootvol->ondisk->vol_name);
686         mp->mnt_stat.f_fsid.val[0] =
687                 crc32((char *)&rootvol->ondisk->vol_fsid + 0, 8);
688         mp->mnt_stat.f_fsid.val[1] =
689                 crc32((char *)&rootvol->ondisk->vol_fsid + 8, 8);
690         mp->mnt_stat.f_fsid.val[1] &= 0x0000FFFF;
691
692         mp->mnt_vstat.f_fsid_uuid = rootvol->ondisk->vol_fsid;
693         mp->mnt_vstat.f_fsid = crc32(&mp->mnt_vstat.f_fsid_uuid,
694                                      sizeof(mp->mnt_vstat.f_fsid_uuid));
695
696         /*
697          * Certain often-modified fields in the root volume are cached in
698          * the hammer_mount structure so we do not have to generate lots
699          * of little UNDO structures for them.
700          *
701          * Recopy after recovery.  This also has the side effect of
702          * setting our cached undo FIFO's first_offset, which serves to
703          * placemark the FIFO start for the NEXT flush cycle while the
704          * on-disk first_offset represents the LAST flush cycle.
705          */
706         hmp->next_tid = rootvol->ondisk->vol0_next_tid;
707         hmp->flush_tid1 = hmp->next_tid;
708         hmp->flush_tid2 = hmp->next_tid;
709         bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
710               sizeof(hmp->blockmap));
711         hmp->copy_stat_freebigblocks = rootvol->ondisk->vol0_stat_freebigblocks;
712
713         hammer_flusher_create(hmp);
714
715         /*
716          * Locate the root directory using the root cluster's B-Tree as a
717          * starting point.  The root directory uses an obj_id of 1.
718          *
719          * FUTURE: Leave the root directory cached referenced but unlocked
720          * in hmp->rootvp (need to flush it on unmount).
721          */
722         error = hammer_vfs_vget(mp, NULL, 1, &rootvp);
723         if (error)
724                 goto done;
725         vput(rootvp);
726         /*vn_unlock(hmp->rootvp);*/
727         if (hmp->ronly == 0)
728                 error = hammer_recover_stage2(hmp, rootvol);
729
730 done:
731         hammer_rel_volume(rootvol, 0);
732 failed:
733         /*
734          * Cleanup and return.
735          */
736         if (error)
737                 hammer_free_hmp(mp);
738         return (error);
739 }
740
741 static int
742 hammer_vfs_unmount(struct mount *mp, int mntflags)
743 {
744 #if 0
745         struct hammer_mount *hmp = (void *)mp->mnt_data;
746 #endif
747         int flags;
748         int error;
749
750         /*
751          * Clean out the vnodes
752          */
753         flags = 0;
754         if (mntflags & MNT_FORCE)
755                 flags |= FORCECLOSE;
756         if ((error = vflush(mp, 0, flags)) != 0)
757                 return (error);
758
759         /*
760          * Clean up the internal mount structure and related entities.  This
761          * may issue I/O.
762          */
763         hammer_free_hmp(mp);
764         return(0);
765 }
766
767 /*
768  * Clean up the internal mount structure and disassociate it from the mount.
769  * This may issue I/O.
770  */
771 static void
772 hammer_free_hmp(struct mount *mp)
773 {
774         struct hammer_mount *hmp = (void *)mp->mnt_data;
775         hammer_flush_group_t flg;
776         int count;
777         int dummy;
778
779         /*
780          * Flush anything dirty.  This won't even run if the
781          * filesystem errored-out.
782          */
783         count = 0;
784         while (hammer_flusher_haswork(hmp)) {
785                 hammer_flusher_sync(hmp);
786                 ++count;
787                 if (count >= 5) {
788                         if (count == 5)
789                                 kprintf("HAMMER: umount flushing.");
790                         else
791                                 kprintf(".");
792                         tsleep(&dummy, 0, "hmrufl", hz);
793                 }
794                 if (count == 30) {
795                         kprintf("giving up\n");
796                         break;
797                 }
798         }
799         if (count >= 5 && count < 30)
800                 kprintf("\n");
801
802         /*
803          * If the mount had a critical error we have to destroy any
804          * remaining inodes before we can finish cleaning up the flusher.
805          */
806         if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) {
807                 RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
808                         hammer_destroy_inode_callback, NULL);
809         }
810
811         /*
812          * There shouldn't be any inodes left now and any left over
813          * flush groups should now be empty.
814          */
815         KKASSERT(RB_EMPTY(&hmp->rb_inos_root));
816         while ((flg = TAILQ_FIRST(&hmp->flush_group_list)) != NULL) {
817                 TAILQ_REMOVE(&hmp->flush_group_list, flg, flush_entry);
818                 KKASSERT(RB_EMPTY(&flg->flush_tree));
819                 if (flg->refs) {
820                         kprintf("HAMMER: Warning, flush_group %p was "
821                                 "not empty on umount!\n", flg);
822                 }
823                 kfree(flg, hmp->m_misc);
824         }
825
826         /*
827          * We can finally destroy the flusher
828          */
829         hammer_flusher_destroy(hmp);
830
831         /*
832          * We may have held recovered buffers due to a read-only mount.
833          * These must be discarded.
834          */
835         if (hmp->ronly)
836                 hammer_recover_flush_buffers(hmp, NULL, -1);
837
838         /*
839          * Unload buffers and then volumes
840          */
841         RB_SCAN(hammer_buf_rb_tree, &hmp->rb_bufs_root, NULL,
842                 hammer_unload_buffer, NULL);
843         RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
844                 hammer_unload_volume, NULL);
845
846         mp->mnt_data = NULL;
847         mp->mnt_flag &= ~MNT_LOCAL;
848         hmp->mp = NULL;
849         hammer_destroy_objid_cache(hmp);
850         kmalloc_destroy(&hmp->m_misc);
851         kmalloc_destroy(&hmp->m_inodes);
852         kfree(hmp, M_HAMMER);
853 }
854
855 /*
856  * Report critical errors.  ip may be NULL.
857  */
858 void
859 hammer_critical_error(hammer_mount_t hmp, hammer_inode_t ip,
860                       int error, const char *msg)
861 {
862         hmp->flags |= HAMMER_MOUNT_CRITICAL_ERROR;
863
864         krateprintf(&hmp->krate,
865                     "HAMMER(%s): Critical error inode=%jd error=%d %s\n",
866                     hmp->mp->mnt_stat.f_mntfromname,
867                     (intmax_t)(ip ? ip->obj_id : -1),
868                     error, msg);
869
870         if (hmp->ronly == 0) {
871                 hmp->ronly = 2;         /* special errored read-only mode */
872                 hmp->mp->mnt_flag |= MNT_RDONLY;
873                 kprintf("HAMMER(%s): Forcing read-only mode\n",
874                         hmp->mp->mnt_stat.f_mntfromname);
875         }
876         hmp->error = error;
877         if (hammer_debug_critical)
878                 Debugger("Entering debugger");
879 }
880
881
882 /*
883  * Obtain a vnode for the specified inode number.  An exclusively locked
884  * vnode is returned.
885  */
886 int
887 hammer_vfs_vget(struct mount *mp, struct vnode *dvp,
888                 ino_t ino, struct vnode **vpp)
889 {
890         struct hammer_transaction trans;
891         struct hammer_mount *hmp = (void *)mp->mnt_data;
892         struct hammer_inode *ip;
893         int error;
894         u_int32_t localization;
895
896         hammer_simple_transaction(&trans, hmp);
897
898         /*
899          * If a directory vnode is supplied (mainly NFS) then we can acquire
900          * the PFS domain from it.  Otherwise we would only be able to vget
901          * inodes in the root PFS.
902          */
903         if (dvp) {
904                 localization = HAMMER_DEF_LOCALIZATION +
905                                 VTOI(dvp)->obj_localization;
906         } else {
907                 localization = HAMMER_DEF_LOCALIZATION;
908         }
909
910         /*
911          * Lookup the requested HAMMER inode.  The structure must be
912          * left unlocked while we manipulate the related vnode to avoid
913          * a deadlock.
914          */
915         ip = hammer_get_inode(&trans, NULL, ino,
916                               hmp->asof, localization,
917                               0, &error);
918         if (ip == NULL) {
919                 *vpp = NULL;
920                 hammer_done_transaction(&trans);
921                 return(error);
922         }
923         error = hammer_get_vnode(ip, vpp);
924         hammer_rel_inode(ip, 0);
925         hammer_done_transaction(&trans);
926         return (error);
927 }
928
929 /*
930  * Return the root vnode for the filesystem.
931  *
932  * HAMMER stores the root vnode in the hammer_mount structure so
933  * getting it is easy.
934  */
935 static int
936 hammer_vfs_root(struct mount *mp, struct vnode **vpp)
937 {
938 #if 0
939         struct hammer_mount *hmp = (void *)mp->mnt_data;
940 #endif
941         int error;
942
943         error = hammer_vfs_vget(mp, NULL, 1, vpp);
944         return (error);
945 }
946
947 static int
948 hammer_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
949 {
950         struct hammer_mount *hmp = (void *)mp->mnt_data;
951         hammer_volume_t volume;
952         hammer_volume_ondisk_t ondisk;
953         int error;
954         int64_t bfree;
955         int64_t breserved;
956
957         volume = hammer_get_root_volume(hmp, &error);
958         if (error)
959                 return(error);
960         ondisk = volume->ondisk;
961
962         /*
963          * Basic stats
964          */
965         _hammer_checkspace(hmp, HAMMER_CHKSPC_WRITE, &breserved);
966         mp->mnt_stat.f_files = ondisk->vol0_stat_inodes;
967         bfree = ondisk->vol0_stat_freebigblocks * HAMMER_LARGEBLOCK_SIZE;
968         hammer_rel_volume(volume, 0);
969
970         mp->mnt_stat.f_bfree = (bfree - breserved) / HAMMER_BUFSIZE;
971         mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
972         if (mp->mnt_stat.f_files < 0)
973                 mp->mnt_stat.f_files = 0;
974
975         *sbp = mp->mnt_stat;
976         return(0);
977 }
978
979 static int
980 hammer_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
981 {
982         struct hammer_mount *hmp = (void *)mp->mnt_data;
983         hammer_volume_t volume;
984         hammer_volume_ondisk_t ondisk;
985         int error;
986         int64_t bfree;
987         int64_t breserved;
988
989         volume = hammer_get_root_volume(hmp, &error);
990         if (error)
991                 return(error);
992         ondisk = volume->ondisk;
993
994         /*
995          * Basic stats
996          */
997         _hammer_checkspace(hmp, HAMMER_CHKSPC_WRITE, &breserved);
998         mp->mnt_vstat.f_files = ondisk->vol0_stat_inodes;
999         bfree = ondisk->vol0_stat_freebigblocks * HAMMER_LARGEBLOCK_SIZE;
1000         hammer_rel_volume(volume, 0);
1001
1002         mp->mnt_vstat.f_bfree = (bfree - breserved) / HAMMER_BUFSIZE;
1003         mp->mnt_vstat.f_bavail = mp->mnt_vstat.f_bfree;
1004         if (mp->mnt_vstat.f_files < 0)
1005                 mp->mnt_vstat.f_files = 0;
1006         *sbp = mp->mnt_vstat;
1007         return(0);
1008 }
1009
1010 /*
1011  * Sync the filesystem.  Currently we have to run it twice, the second
1012  * one will advance the undo start index to the end index, so if a crash
1013  * occurs no undos will be run on mount.
1014  *
1015  * We do not sync the filesystem if we are called from a panic.  If we did
1016  * we might end up blowing up a sync that was already in progress.
1017  */
1018 static int
1019 hammer_vfs_sync(struct mount *mp, int waitfor)
1020 {
1021         struct hammer_mount *hmp = (void *)mp->mnt_data;
1022         int error;
1023
1024         if (panicstr == NULL) {
1025                 error = hammer_sync_hmp(hmp, waitfor);
1026         } else {
1027                 error = EIO;
1028         }
1029         return (error);
1030 }
1031
1032 /*
1033  * Convert a vnode to a file handle.
1034  */
1035 static int
1036 hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp)
1037 {
1038         hammer_inode_t ip;
1039
1040         KKASSERT(MAXFIDSZ >= 16);
1041         ip = VTOI(vp);
1042         fhp->fid_len = offsetof(struct fid, fid_data[16]);
1043         fhp->fid_ext = ip->obj_localization >> 16;
1044         bcopy(&ip->obj_id, fhp->fid_data + 0, sizeof(ip->obj_id));
1045         bcopy(&ip->obj_asof, fhp->fid_data + 8, sizeof(ip->obj_asof));
1046         return(0);
1047 }
1048
1049
1050 /*
1051  * Convert a file handle back to a vnode.
1052  *
1053  * Use rootvp to enforce PFS isolation when a PFS is exported via a
1054  * null mount.
1055  */
1056 static int
1057 hammer_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
1058                   struct fid *fhp, struct vnode **vpp)
1059 {
1060         struct hammer_transaction trans;
1061         struct hammer_inode *ip;
1062         struct hammer_inode_info info;
1063         int error;
1064         u_int32_t localization;
1065
1066         bcopy(fhp->fid_data + 0, &info.obj_id, sizeof(info.obj_id));
1067         bcopy(fhp->fid_data + 8, &info.obj_asof, sizeof(info.obj_asof));
1068         if (rootvp)
1069                 localization = VTOI(rootvp)->obj_localization;
1070         else
1071                 localization = (u_int32_t)fhp->fid_ext << 16;
1072
1073         hammer_simple_transaction(&trans, (void *)mp->mnt_data);
1074
1075         /*
1076          * Get/allocate the hammer_inode structure.  The structure must be
1077          * unlocked while we manipulate the related vnode to avoid a
1078          * deadlock.
1079          */
1080         ip = hammer_get_inode(&trans, NULL, info.obj_id,
1081                               info.obj_asof, localization, 0, &error);
1082         if (ip) {
1083                 error = hammer_get_vnode(ip, vpp);
1084                 hammer_rel_inode(ip, 0);
1085         } else {
1086                 *vpp = NULL;
1087         }
1088         hammer_done_transaction(&trans);
1089         return (error);
1090 }
1091
1092 static int
1093 hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
1094                     int *exflagsp, struct ucred **credanonp)
1095 {
1096         hammer_mount_t hmp = (void *)mp->mnt_data;
1097         struct netcred *np;
1098         int error;
1099
1100         np = vfs_export_lookup(mp, &hmp->export, nam);
1101         if (np) {
1102                 *exflagsp = np->netc_exflags;
1103                 *credanonp = &np->netc_anon;
1104                 error = 0;
1105         } else {
1106                 error = EACCES;
1107         }
1108         return (error);
1109
1110 }
1111
1112 int
1113 hammer_vfs_export(struct mount *mp, int op, const struct export_args *export)
1114 {
1115         hammer_mount_t hmp = (void *)mp->mnt_data;
1116         int error;
1117
1118         switch(op) {
1119         case MOUNTCTL_SET_EXPORT:
1120                 error = vfs_export(mp, &hmp->export, export);
1121                 break;
1122         default:
1123                 error = EOPNOTSUPP;
1124                 break;
1125         }
1126         return(error);
1127 }
1128