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          * Internal 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                 lwkt_gettoken(&hmp->fs_token);
 471                 error = 0;
 472                 if (hmp->ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
 473                         kprintf("HAMMER read-only -> read-write\n");
 474                         hmp->ronly = 0;
 475                         RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
 476                                 hammer_adjust_volume_mode, NULL);
 477                         rootvol = hammer_get_root_volume(hmp, &error);
 478                         if (rootvol) {
 479                                 hammer_recover_flush_buffers(hmp, rootvol, 1);
 480                                 error = hammer_recover_stage2(hmp, rootvol);
 481                                 bcopy(rootvol->ondisk->vol0_blockmap,
 482                                       hmp->blockmap,
 483                                       sizeof(hmp->blockmap));
 484                                 hammer_rel_volume(rootvol, 0);
 485                         }
 486                         RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
 487                                 hammer_reload_inode, NULL);
 488                         /* kernel clears MNT_RDONLY */
 489                 } else if (hmp->ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
 490                         kprintf("HAMMER read-write -> read-only\n");
 491                         hmp->ronly = 1; /* messy */
 492                         RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
 493                                 hammer_reload_inode, NULL);
 494                         hmp->ronly = 0;
 495                         hammer_flusher_sync(hmp);
 496                         hammer_flusher_sync(hmp);
 497                         hammer_flusher_sync(hmp);
 498                         hmp->ronly = 1;
 499                         RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
 500                                 hammer_adjust_volume_mode, NULL);
 501                 }
 502                 lwkt_reltoken(&hmp->fs_token);
 503                 return(error);
 504         }
 505
 506         RB_INIT(&hmp->rb_vols_root);
 507         RB_INIT(&hmp->rb_inos_root);
 508         RB_INIT(&hmp->rb_redo_root);
 509         RB_INIT(&hmp->rb_nods_root);
 510         RB_INIT(&hmp->rb_undo_root);
 511         RB_INIT(&hmp->rb_resv_root);
 512         RB_INIT(&hmp->rb_bufs_root);
 513         RB_INIT(&hmp->rb_pfsm_root);
 514
 515         hmp->ronly = ((mp->mnt_flag & MNT_RDONLY) != 0);
 516
 517         TAILQ_INIT(&hmp->volu_list);
 518         TAILQ_INIT(&hmp->undo_list);
 519         TAILQ_INIT(&hmp->data_list);
 520         TAILQ_INIT(&hmp->meta_list);
 521         TAILQ_INIT(&hmp->lose_list);
 522         TAILQ_INIT(&hmp->iorun_list);
 523
 524         lwkt_token_init(&hmp->fs_token, 1, "hammerfs");
 525         lwkt_token_init(&hmp->io_token, 1, "hammerio");
 526
 527         lwkt_gettoken(&hmp->fs_token);
 528
 529         /*
 530          * Load volumes
 531          */
 532         path = objcache_get(namei_oc, M_WAITOK);
 533         hmp->nvolumes = -1;
 534         for (i = 0; i < info.nvolumes; ++i) {
 535                 if (mntpt == NULL) {
 536                         /*
 537                          * Root mount.
 538                          */
 539                         KKASSERT(next_volume_ptr != NULL);
 540                         strcpy(path, "");
 541                         if (*next_volume_ptr != '/') {
 542                                 /* relative path */
 543                                 strcpy(path, "/dev/");
 544                         }
 545                         int k;
 546                         for (k = strlen(path); k < MAXPATHLEN-1; ++k) {
 547                                 if (*next_volume_ptr == '\0') {
 548                                         break;
 549                                 } else if (*next_volume_ptr == ':') {
 550                                         ++next_volume_ptr;
 551                                         break;
 552                                 } else {
 553                                         path[k] = *next_volume_ptr;
 554                                         ++next_volume_ptr;
 555                                 }
 556                         }
 557                         path[k] = '\0';
 558
 559                         error = 0;
 560                         cdev_t dev = kgetdiskbyname(path);
 561                         error = bdevvp(dev, &devvp);
 562                         if (error) {
 563                                 kprintf("hammer_mountroot: can't find devvp\n");
 564                         }
 565                 } else {
 566                         error = copyin(&info.volumes[i], &upath,
 567                                        sizeof(char *));
 568                         if (error == 0)
 569                                 error = copyinstr(upath, path,
 570                                                   MAXPATHLEN, NULL);
 571                 }
 572                 if (error == 0)
 573                         error = hammer_install_volume(hmp, path, devvp);
 574                 if (error)
 575                         break;
 576         }
 577         objcache_put(namei_oc, path);
 578
 579         /*
 580          * Make sure we found a root volume
 581          */
 582         if (error == 0 && hmp->rootvol == NULL) {
 583                 kprintf("hammer_mount: No root volume found!\n");
 584                 error = EINVAL;
 585         }
 586
 587         /*
 588          * Check that all required volumes are available
 589          */
 590         if (error == 0 && hammer_mountcheck_volumes(hmp)) {
 591                 kprintf("hammer_mount: Missing volumes, cannot mount!\n");
 592                 error = EINVAL;
 593         }
 594
 595         if (error) {
 596                 /* called with fs_token held */
 597                 hammer_free_hmp(mp);
 598                 return (error);
 599         }
 600
 601         /*
 602          * No errors, setup enough of the mount point so we can lookup the
 603          * root vnode.
 604          */
 605         mp->mnt_iosize_max = MAXPHYS;
 606         mp->mnt_kern_flag |= MNTK_FSMID;
 607
 608         /*
 609          * MPSAFE code.  Note that VOPs and VFSops which are not MPSAFE
 610          * will acquire a per-mount token prior to entry and release it
 611          * on return, so even if we do not specify it we no longer get
 612          * the BGL regardlless of how we are flagged.
 613          */
 614         mp->mnt_kern_flag |= MNTK_ALL_MPSAFE;
 615         /*MNTK_RD_MPSAFE | MNTK_GA_MPSAFE | MNTK_IN_MPSAFE;*/
 616
 617         /*
 618          * note: f_iosize is used by vnode_pager_haspage() when constructing
 619          * its VOP_BMAP call.
 620          */
 621         mp->mnt_stat.f_iosize = HAMMER_BUFSIZE;
 622         mp->mnt_stat.f_bsize = HAMMER_BUFSIZE;
 623
 624         mp->mnt_vstat.f_frsize = HAMMER_BUFSIZE;
 625         mp->mnt_vstat.f_bsize = HAMMER_BUFSIZE;
 626
 627         mp->mnt_maxsymlinklen = 255;
 628         mp->mnt_flag |= MNT_LOCAL;
 629
 630         vfs_add_vnodeops(mp, &hammer_vnode_vops, &mp->mnt_vn_norm_ops);
 631         vfs_add_vnodeops(mp, &hammer_spec_vops, &mp->mnt_vn_spec_ops);
 632         vfs_add_vnodeops(mp, &hammer_fifo_vops, &mp->mnt_vn_fifo_ops);
 633
 634         /*
 635          * The root volume's ondisk pointer is only valid if we hold a
 636          * reference to it.
 637          */
 638         rootvol = hammer_get_root_volume(hmp, &error);
 639         if (error)
 640                 goto failed;
 641
 642         /*
 643          * Perform any necessary UNDO operations.  The recovery code does
 644          * call hammer_undo_lookup() so we have to pre-cache the blockmap,
 645          * and then re-copy it again after recovery is complete.
 646          *
 647          * If this is a read-only mount the UNDO information is retained
 648          * in memory in the form of dirty buffer cache buffers, and not
 649          * written back to the media.
 650          */
 651         bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
 652               sizeof(hmp->blockmap));
 653
 654         /*
 655          * Check filesystem version
 656          */
 657         hmp->version = rootvol->ondisk->vol_version;
 658         if (hmp->version < HAMMER_VOL_VERSION_MIN ||
 659             hmp->version > HAMMER_VOL_VERSION_MAX) {
 660                 kprintf("HAMMER: mount unsupported fs version %d\n",
 661                         hmp->version);
 662                 error = ERANGE;
 663                 goto done;
 664         }
 665
 666         /*
 667          * The undo_rec_limit limits the size of flush groups to avoid
 668          * blowing out the UNDO FIFO.  This calculation is typically in
 669          * the tens of thousands and is designed primarily when small
 670          * HAMMER filesystems are created.
 671          */
 672         hmp->undo_rec_limit = hammer_undo_max(hmp) / 8192 + 100;
 673         if (hammer_debug_general & 0x0001)
 674                 kprintf("HAMMER: undo_rec_limit %d\n", hmp->undo_rec_limit);
 675
 676         /*
 677          * NOTE: Recover stage1 not only handles meta-data recovery, it
 678          *       also sets hmp->undo_seqno for HAMMER VERSION 4+ filesystems.
 679          */
 680         error = hammer_recover_stage1(hmp, rootvol);
 681         if (error) {
 682                 kprintf("Failed to recover HAMMER filesystem on mount\n");
 683                 goto done;
 684         }
 685
 686         /*
 687          * Finish setup now that we have a good root volume.
 688          *
 689          * The top 16 bits of fsid.val[1] is a pfs id.
 690          */
 691         ksnprintf(mp->mnt_stat.f_mntfromname,
 692                   sizeof(mp->mnt_stat.f_mntfromname), "%s",
 693                   rootvol->ondisk->vol_name);
 694         mp->mnt_stat.f_fsid.val[0] =
 695                 crc32((char *)&rootvol->ondisk->vol_fsid + 0, 8);
 696         mp->mnt_stat.f_fsid.val[1] =
 697                 crc32((char *)&rootvol->ondisk->vol_fsid + 8, 8);
 698         mp->mnt_stat.f_fsid.val[1] &= 0x0000FFFF;
 699
 700         mp->mnt_vstat.f_fsid_uuid = rootvol->ondisk->vol_fsid;
 701         mp->mnt_vstat.f_fsid = crc32(&mp->mnt_vstat.f_fsid_uuid,
 702                                      sizeof(mp->mnt_vstat.f_fsid_uuid));
 703
 704         /*
 705          * Certain often-modified fields in the root volume are cached in
 706          * the hammer_mount structure so we do not have to generate lots
 707          * of little UNDO structures for them.
 708          *
 709          * Recopy after recovery.  This also has the side effect of
 710          * setting our cached undo FIFO's first_offset, which serves to
 711          * placemark the FIFO start for the NEXT flush cycle while the
 712          * on-disk first_offset represents the LAST flush cycle.
 713          */
 714         hmp->next_tid = rootvol->ondisk->vol0_next_tid;
 715         hmp->flush_tid1 = hmp->next_tid;
 716         hmp->flush_tid2 = hmp->next_tid;
 717         bcopy(rootvol->ondisk->vol0_blockmap, hmp->blockmap,
 718               sizeof(hmp->blockmap));
 719         hmp->copy_stat_freebigblocks = rootvol->ondisk->vol0_stat_freebigblocks;
 720
 721         hammer_flusher_create(hmp);
 722
 723         /*
 724          * Locate the root directory using the root cluster's B-Tree as a
 725          * starting point.  The root directory uses an obj_id of 1.
 726          *
 727          * FUTURE: Leave the root directory cached referenced but unlocked
 728          * in hmp->rootvp (need to flush it on unmount).
 729          */
 730         error = hammer_vfs_vget(mp, NULL, 1, &rootvp);
 731         if (error)
 732                 goto done;
 733         vput(rootvp);
 734         /*vn_unlock(hmp->rootvp);*/
 735         if (hmp->ronly == 0)
 736                 error = hammer_recover_stage2(hmp, rootvol);
 737
 738         /*
 739          * If the stage2 recovery fails be sure to clean out all cached
 740          * vnodes before throwing away the mount structure or bad things
 741          * will happen.
 742          */
 743         if (error)
 744                 vflush(mp, 0, 0);
 745
 746 done:
 747         hammer_rel_volume(rootvol, 0);
 748 failed:
 749         /*
 750          * Cleanup and return.
 751          */
 752         if (error) {
 753                 /* called with fs_token held */
 754                 hammer_free_hmp(mp);
 755         } else {
 756                 lwkt_reltoken(&hmp->fs_token);
 757         }
 758         return (error);
 759 }
 760
 761 static int
 762 hammer_vfs_unmount(struct mount *mp, int mntflags)
 763 {
 764         hammer_mount_t hmp = (void *)mp->mnt_data;
 765         int flags;
 766         int error;
 767
 768         /*
 769          * Clean out the vnodes
 770          */
 771         lwkt_gettoken(&hmp->fs_token);
 772         flags = 0;
 773         if (mntflags & MNT_FORCE)
 774                 flags |= FORCECLOSE;
 775         error = vflush(mp, 0, flags);
 776
 777         /*
 778          * Clean up the internal mount structure and related entities.  This
 779          * may issue I/O.
 780          */
 781         if (error == 0) {
 782                 /* called with fs_token held */
 783                 hammer_free_hmp(mp);
 784         } else {
 785                 lwkt_reltoken(&hmp->fs_token);
 786         }
 787         return(error);
 788 }
 789
 790 /*
 791  * Clean up the internal mount structure and disassociate it from the mount.
 792  * This may issue I/O.
 793  *
 794  * Called with fs_token held.
 795  */
 796 static void
 797 hammer_free_hmp(struct mount *mp)
 798 {
 799         hammer_mount_t hmp = (void *)mp->mnt_data;
 800         hammer_flush_group_t flg;
 801         int count;
 802         int dummy;
 803
 804         /*
 805          * Flush anything dirty.  This won't even run if the
 806          * filesystem errored-out.
 807          */
 808         count = 0;
 809         while (hammer_flusher_haswork(hmp)) {
 810                 hammer_flusher_sync(hmp);
 811                 ++count;
 812                 if (count >= 5) {
 813                         if (count == 5)
 814                                 kprintf("HAMMER: umount flushing.");
 815                         else
 816                                 kprintf(".");
 817                         tsleep(&dummy, 0, "hmrufl", hz);
 818                 }
 819                 if (count == 30) {
 820                         kprintf("giving up\n");
 821                         break;
 822                 }
 823         }
 824         if (count >= 5 && count < 30)
 825                 kprintf("\n");
 826
 827         /*
 828          * If the mount had a critical error we have to destroy any
 829          * remaining inodes before we can finish cleaning up the flusher.
 830          */
 831         if (hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR) {
 832                 RB_SCAN(hammer_ino_rb_tree, &hmp->rb_inos_root, NULL,
 833                         hammer_destroy_inode_callback, NULL);
 834         }
 835
 836         /*
 837          * There shouldn't be any inodes left now and any left over
 838          * flush groups should now be empty.
 839          */
 840         KKASSERT(RB_EMPTY(&hmp->rb_inos_root));
 841         while ((flg = TAILQ_FIRST(&hmp->flush_group_list)) != NULL) {
 842                 TAILQ_REMOVE(&hmp->flush_group_list, flg, flush_entry);
 843                 KKASSERT(RB_EMPTY(&flg->flush_tree));
 844                 if (flg->refs) {
 845                         kprintf("HAMMER: Warning, flush_group %p was "
 846                                 "not empty on umount!\n", flg);
 847                 }
 848                 kfree(flg, hmp->m_misc);
 849         }
 850
 851         /*
 852          * We can finally destroy the flusher
 853          */
 854         hammer_flusher_destroy(hmp);
 855
 856         /*
 857          * We may have held recovered buffers due to a read-only mount.
 858          * These must be discarded.
 859          */
 860         if (hmp->ronly)
 861                 hammer_recover_flush_buffers(hmp, NULL, -1);
 862
 863         /*
 864          * Unload buffers and then volumes
 865          */
 866         RB_SCAN(hammer_buf_rb_tree, &hmp->rb_bufs_root, NULL,
 867                 hammer_unload_buffer, NULL);
 868         RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
 869                 hammer_unload_volume, NULL);
 870
 871         mp->mnt_data = NULL;
 872         mp->mnt_flag &= ~MNT_LOCAL;
 873         hmp->mp = NULL;
 874         hammer_destroy_objid_cache(hmp);
 875         kmalloc_destroy(&hmp->m_misc);
 876         kmalloc_destroy(&hmp->m_inodes);
 877         lwkt_reltoken(&hmp->fs_token);
 878         kfree(hmp, M_HAMMER);
 879 }
 880
 881 /*
 882  * Report critical errors.  ip may be NULL.
 883  */
 884 void
 885 hammer_critical_error(hammer_mount_t hmp, hammer_inode_t ip,
 886                       int error, const char *msg)
 887 {
 888         hmp->flags |= HAMMER_MOUNT_CRITICAL_ERROR;
 889
 890         krateprintf(&hmp->krate,
 891                     "HAMMER(%s): Critical error inode=%jd error=%d %s\n",
 892                     hmp->mp->mnt_stat.f_mntfromname,
 893                     (intmax_t)(ip ? ip->obj_id : -1),
 894                     error, msg);
 895
 896         if (hmp->ronly == 0) {
 897                 hmp->ronly = 2;         /* special errored read-only mode */
 898                 hmp->mp->mnt_flag |= MNT_RDONLY;
 899                 kprintf("HAMMER(%s): Forcing read-only mode\n",
 900                         hmp->mp->mnt_stat.f_mntfromname);
 901         }
 902         hmp->error = error;
 903         if (hammer_debug_critical)
 904                 Debugger("Entering debugger");
 905 }
 906
 907
 908 /*
 909  * Obtain a vnode for the specified inode number.  An exclusively locked
 910  * vnode is returned.
 911  */
 912 int
 913 hammer_vfs_vget(struct mount *mp, struct vnode *dvp,
 914                 ino_t ino, struct vnode **vpp)
 915 {
 916         struct hammer_transaction trans;
 917         struct hammer_mount *hmp = (void *)mp->mnt_data;
 918         struct hammer_inode *ip;
 919         int error;
 920         u_int32_t localization;
 921
 922         lwkt_gettoken(&hmp->fs_token);
 923         hammer_simple_transaction(&trans, hmp);
 924
 925         /*
 926          * If a directory vnode is supplied (mainly NFS) then we can acquire
 927          * the PFS domain from it.  Otherwise we would only be able to vget
 928          * inodes in the root PFS.
 929          */
 930         if (dvp) {
 931                 localization = HAMMER_DEF_LOCALIZATION +
 932                                 VTOI(dvp)->obj_localization;
 933         } else {
 934                 localization = HAMMER_DEF_LOCALIZATION;
 935         }
 936
 937         /*
 938          * Lookup the requested HAMMER inode.  The structure must be
 939          * left unlocked while we manipulate the related vnode to avoid
 940          * a deadlock.
 941          */
 942         ip = hammer_get_inode(&trans, NULL, ino,
 943                               hmp->asof, localization,
 944                               0, &error);
 945         if (ip == NULL) {
 946                 *vpp = NULL;
 947         } else {
 948                 error = hammer_get_vnode(ip, vpp);
 949                 hammer_rel_inode(ip, 0);
 950         }
 951         hammer_done_transaction(&trans);
 952         lwkt_reltoken(&hmp->fs_token);
 953         return (error);
 954 }
 955
 956 /*
 957  * Return the root vnode for the filesystem.
 958  *
 959  * HAMMER stores the root vnode in the hammer_mount structure so
 960  * getting it is easy.
 961  */
 962 static int
 963 hammer_vfs_root(struct mount *mp, struct vnode **vpp)
 964 {
 965         int error;
 966
 967         error = hammer_vfs_vget(mp, NULL, 1, vpp);
 968         return (error);
 969 }
 970
 971 static int
 972 hammer_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
 973 {
 974         struct hammer_mount *hmp = (void *)mp->mnt_data;
 975         hammer_volume_t volume;
 976         hammer_volume_ondisk_t ondisk;
 977         int error;
 978         int64_t bfree;
 979         int64_t breserved;
 980
 981         lwkt_gettoken(&hmp->fs_token);
 982         volume = hammer_get_root_volume(hmp, &error);
 983         if (error) {
 984                 lwkt_reltoken(&hmp->fs_token);
 985                 return(error);
 986         }
 987         ondisk = volume->ondisk;
 988
 989         /*
 990          * Basic stats
 991          */
 992         _hammer_checkspace(hmp, HAMMER_CHKSPC_WRITE, &breserved);
 993         mp->mnt_stat.f_files = ondisk->vol0_stat_inodes;
 994         bfree = ondisk->vol0_stat_freebigblocks * HAMMER_LARGEBLOCK_SIZE;
 995         hammer_rel_volume(volume, 0);
 996
 997         mp->mnt_stat.f_bfree = (bfree - breserved) / HAMMER_BUFSIZE;
 998         mp->mnt_stat.f_bavail = mp->mnt_stat.f_bfree;
 999         if (mp->mnt_stat.f_files < 0)
1000                 mp->mnt_stat.f_files = 0;
1001
1002         *sbp = mp->mnt_stat;
1003         lwkt_reltoken(&hmp->fs_token);
1004         return(0);
1005 }
1006
1007 static int
1008 hammer_vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
1009 {
1010         struct hammer_mount *hmp = (void *)mp->mnt_data;
1011         hammer_volume_t volume;
1012         hammer_volume_ondisk_t ondisk;
1013         int error;
1014         int64_t bfree;
1015         int64_t breserved;
1016
1017         lwkt_gettoken(&hmp->fs_token);
1018         volume = hammer_get_root_volume(hmp, &error);
1019         if (error) {
1020                 lwkt_reltoken(&hmp->fs_token);
1021                 return(error);
1022         }
1023         ondisk = volume->ondisk;
1024
1025         /*
1026          * Basic stats
1027          */
1028         _hammer_checkspace(hmp, HAMMER_CHKSPC_WRITE, &breserved);
1029         mp->mnt_vstat.f_files = ondisk->vol0_stat_inodes;
1030         bfree = ondisk->vol0_stat_freebigblocks * HAMMER_LARGEBLOCK_SIZE;
1031         hammer_rel_volume(volume, 0);
1032
1033         mp->mnt_vstat.f_bfree = (bfree - breserved) / HAMMER_BUFSIZE;
1034         mp->mnt_vstat.f_bavail = mp->mnt_vstat.f_bfree;
1035         if (mp->mnt_vstat.f_files < 0)
1036                 mp->mnt_vstat.f_files = 0;
1037         *sbp = mp->mnt_vstat;
1038         lwkt_reltoken(&hmp->fs_token);
1039         return(0);
1040 }
1041
1042 /*
1043  * Sync the filesystem.  Currently we have to run it twice, the second
1044  * one will advance the undo start index to the end index, so if a crash
1045  * occurs no undos will be run on mount.
1046  *
1047  * We do not sync the filesystem if we are called from a panic.  If we did
1048  * we might end up blowing up a sync that was already in progress.
1049  */
1050 static int
1051 hammer_vfs_sync(struct mount *mp, int waitfor)
1052 {
1053         struct hammer_mount *hmp = (void *)mp->mnt_data;
1054         int error;
1055
1056         lwkt_gettoken(&hmp->fs_token);
1057         if (panicstr == NULL) {
1058                 error = hammer_sync_hmp(hmp, waitfor);
1059         } else {
1060                 error = EIO;
1061         }
1062         lwkt_reltoken(&hmp->fs_token);
1063         return (error);
1064 }
1065
1066 /*
1067  * Convert a vnode to a file handle.
1068  *
1069  * Accesses read-only fields on already-referenced structures so
1070  * no token is needed.
1071  */
1072 static int
1073 hammer_vfs_vptofh(struct vnode *vp, struct fid *fhp)
1074 {
1075         hammer_inode_t ip;
1076
1077         KKASSERT(MAXFIDSZ >= 16);
1078         ip = VTOI(vp);
1079         fhp->fid_len = offsetof(struct fid, fid_data[16]);
1080         fhp->fid_ext = ip->obj_localization >> 16;
1081         bcopy(&ip->obj_id, fhp->fid_data + 0, sizeof(ip->obj_id));
1082         bcopy(&ip->obj_asof, fhp->fid_data + 8, sizeof(ip->obj_asof));
1083         return(0);
1084 }
1085
1086
1087 /*
1088  * Convert a file handle back to a vnode.
1089  *
1090  * Use rootvp to enforce PFS isolation when a PFS is exported via a
1091  * null mount.
1092  */
1093 static int
1094 hammer_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
1095                   struct fid *fhp, struct vnode **vpp)
1096 {
1097         hammer_mount_t hmp = (void *)mp->mnt_data;
1098         struct hammer_transaction trans;
1099         struct hammer_inode *ip;
1100         struct hammer_inode_info info;
1101         int error;
1102         u_int32_t localization;
1103
1104         bcopy(fhp->fid_data + 0, &info.obj_id, sizeof(info.obj_id));
1105         bcopy(fhp->fid_data + 8, &info.obj_asof, sizeof(info.obj_asof));
1106         if (rootvp)
1107                 localization = VTOI(rootvp)->obj_localization;
1108         else
1109                 localization = (u_int32_t)fhp->fid_ext << 16;
1110
1111         lwkt_gettoken(&hmp->fs_token);
1112         hammer_simple_transaction(&trans, hmp);
1113
1114         /*
1115          * Get/allocate the hammer_inode structure.  The structure must be
1116          * unlocked while we manipulate the related vnode to avoid a
1117          * deadlock.
1118          */
1119         ip = hammer_get_inode(&trans, NULL, info.obj_id,
1120                               info.obj_asof, localization, 0, &error);
1121         if (ip) {
1122                 error = hammer_get_vnode(ip, vpp);
1123                 hammer_rel_inode(ip, 0);
1124         } else {
1125                 *vpp = NULL;
1126         }
1127         hammer_done_transaction(&trans);
1128         lwkt_reltoken(&hmp->fs_token);
1129         return (error);
1130 }
1131
1132 static int
1133 hammer_vfs_checkexp(struct mount *mp, struct sockaddr *nam,
1134                     int *exflagsp, struct ucred **credanonp)
1135 {
1136         hammer_mount_t hmp = (void *)mp->mnt_data;
1137         struct netcred *np;
1138         int error;
1139
1140         lwkt_gettoken(&hmp->fs_token);
1141         np = vfs_export_lookup(mp, &hmp->export, nam);
1142         if (np) {
1143                 *exflagsp = np->netc_exflags;
1144                 *credanonp = &np->netc_anon;
1145                 error = 0;
1146         } else {
1147                 error = EACCES;
1148         }
1149         lwkt_reltoken(&hmp->fs_token);
1150         return (error);
1151
1152 }
1153
1154 int
1155 hammer_vfs_export(struct mount *mp, int op, const struct export_args *export)
1156 {
1157         hammer_mount_t hmp = (void *)mp->mnt_data;
1158         int error;
1159
1160         lwkt_gettoken(&hmp->fs_token);
1161
1162         switch(op) {
1163         case MOUNTCTL_SET_EXPORT:
1164                 error = vfs_export(mp, &hmp->export, export);
1165                 break;
1166         default:
1167                 error = EOPNOTSUPP;
1168                 break;
1169         }
1170         lwkt_reltoken(&hmp->fs_token);
1171
1172         return(error);
1173 }
1174