sys/vfs/hammer/hammer_ioctl.c

   1 /*
   2  * Copyright (c) 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_ioctl.c,v 1.3 2008/02/06 08:59:28 dillon Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 static int hammer_ioc_prune(hammer_inode_t ip,
  40                                 struct hammer_ioc_prune *prune);
  41 static int hammer_ioc_gethistory(hammer_inode_t ip,
  42                                 struct hammer_ioc_history *hist);
  43
  44 int
  45 hammer_ioctl(hammer_inode_t ip, u_long com, caddr_t data, int fflag,
  46              struct ucred *cred)
  47 {
  48         int error;
  49
  50         error = suser_cred(cred, PRISON_ROOT);
  51
  52         switch(com) {
  53         case HAMMERIOC_PRUNE:
  54                 if (error == 0) {
  55                         error = hammer_ioc_prune(ip,
  56                                         (struct hammer_ioc_prune *)data);
  57                 }
  58                 break;
  59         case HAMMERIOC_GETHISTORY:
  60                 error = hammer_ioc_gethistory(ip,
  61                                         (struct hammer_ioc_history *)data);
  62                 break;
  63         default:
  64                 error = EOPNOTSUPP;
  65                 break;
  66         }
  67         return (error);
  68 }
  69
  70 /*
  71  * Iterate through the specified range of object ids and remove any
  72  * deleted records that fall entirely within a prune modulo.
  73  *
  74  * A reverse iteration is used to prevent overlapping records from being
  75  * created during the iteration due to alignments.  This also allows us
  76  * to adjust alignments without blowing up the B-Tree.
  77  */
  78 static int check_prune(struct hammer_ioc_prune *prune, hammer_btree_elm_t elm,
  79                         int *realign_cre, int *realign_del);
  80 static int realign_prune(struct hammer_ioc_prune *prune, hammer_cursor_t cursor,
  81                         int realign_cre, int realign_del);
  82
  83 static int
  84 hammer_ioc_prune(hammer_inode_t ip, struct hammer_ioc_prune *prune)
  85 {
  86         struct hammer_cursor cursor;
  87         hammer_btree_elm_t elm;
  88         int error;
  89         int isdir;
  90         int realign_cre;
  91         int realign_del;
  92
  93         if (prune->nelms < 0 || prune->nelms > HAMMER_MAX_PRUNE_ELMS)
  94                 return(EINVAL);
  95         if (prune->beg_obj_id >= prune->end_obj_id)
  96                 return(EINVAL);
  97         if ((prune->flags & HAMMER_IOC_PRUNE_ALL) && prune->nelms)
  98                 return(EINVAL);
  99
 100 retry:
 101         error = hammer_init_cursor_hmp(&cursor, NULL, ip->hmp);
 102         if (error) {
 103                 hammer_done_cursor(&cursor);
 104                 return(error);
 105         }
 106         cursor.key_beg.obj_id = prune->beg_obj_id;
 107         cursor.key_beg.key = HAMMER_MIN_KEY;
 108         cursor.key_beg.create_tid = 1;
 109         cursor.key_beg.delete_tid = 0;
 110         cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
 111         cursor.key_beg.obj_type = 0;
 112
 113         cursor.key_end.obj_id = prune->cur_obj_id;
 114         cursor.key_end.key = prune->cur_key;
 115         cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
 116         cursor.key_end.delete_tid = 0;
 117         cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
 118         cursor.key_end.obj_type = 0;
 119
 120         cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
 121
 122         error = hammer_btree_last(&cursor);
 123         while (error == 0) {
 124                 elm = &cursor.node->ondisk->elms[cursor.index];
 125                 prune->cur_obj_id = elm->base.obj_id;
 126                 prune->cur_key = elm->base.key;
 127
 128                 if (check_prune(prune, elm, &realign_cre, &realign_del) == 0) {
 129                         if (hammer_debug_general & 0x0200) {
 130                                 kprintf("check %016llx %016llx: DELETE\n",
 131                                         elm->base.obj_id, elm->base.key);
 132                         }
 133
 134                         /*
 135                          * NOTE: This can return EDEADLK
 136                          */
 137                         isdir = (elm->base.rec_type == HAMMER_RECTYPE_DIRENTRY);
 138
 139                         error = hammer_delete_at_cursor(&cursor,
 140                                                         &prune->stat_bytes);
 141                         if (error)
 142                                 break;
 143
 144                         if (isdir)
 145                                 ++prune->stat_dirrecords;
 146                         else
 147                                 ++prune->stat_rawrecords;
 148                 } else if (realign_cre >= 0 || realign_del >= 0) {
 149                         error = realign_prune(prune, &cursor,
 150                                               realign_cre, realign_del);
 151                         if (error == 0) {
 152                                 cursor.flags |= HAMMER_CURSOR_ATEDISK;
 153                                 if (hammer_debug_general & 0x0200) {
 154                                         kprintf("check %016llx %016llx: "
 155                                                 "REALIGN\n",
 156                                                 elm->base.obj_id,
 157                                                 elm->base.key);
 158                                 }
 159                         }
 160                 } else {
 161                         cursor.flags |= HAMMER_CURSOR_ATEDISK;
 162                         if (hammer_debug_general & 0x0100) {
 163                                 kprintf("check %016llx %016llx: SKIP\n",
 164                                         elm->base.obj_id, elm->base.key);
 165                         }
 166                 }
 167                 if (error == 0)
 168                         error = hammer_btree_iterate_reverse(&cursor);
 169         }
 170         if (error == ENOENT)
 171                 error = 0;
 172         hammer_done_cursor(&cursor);
 173         if (error == EDEADLK)
 174                 goto retry;
 175         return(error);
 176 }
 177
 178 /*
 179  * Check pruning list.  The list must be sorted in descending order.
 180  */
 181 static int
 182 check_prune(struct hammer_ioc_prune *prune, hammer_btree_elm_t elm,
 183             int *realign_cre, int *realign_del)
 184 {
 185         struct hammer_ioc_prune_elm *scan;
 186         int i;
 187
 188         *realign_cre = -1;
 189         *realign_del = -1;
 190
 191         /*
 192          * If pruning everything remove all records with a non-zero
 193          * delete_tid.
 194          */
 195         if (prune->flags & HAMMER_IOC_PRUNE_ALL) {
 196                 if (elm->base.delete_tid != 0)
 197                         return(0);
 198                 return(-1);
 199         }
 200
 201         for (i = 0; i < prune->nelms; ++i) {
 202                 scan = &prune->elms[i];
 203
 204                 /*
 205                  * Locate the scan index covering the create and delete TIDs.
 206                  */
 207                 if (*realign_cre < 0 &&
 208                     elm->base.create_tid >= scan->beg_tid &&
 209                     elm->base.create_tid < scan->end_tid) {
 210                         *realign_cre = i;
 211                 }
 212                 if (*realign_del < 0 && elm->base.delete_tid &&
 213                     elm->base.delete_tid > scan->beg_tid &&
 214                     elm->base.delete_tid <= scan->end_tid) {
 215                         *realign_del = i;
 216                 }
 217
 218                 /*
 219                  * Now check for loop termination.
 220                  */
 221                 if (elm->base.create_tid >= scan->end_tid ||
 222                     elm->base.delete_tid > scan->end_tid) {
 223                         break;
 224                 }
 225
 226                 /*
 227                  * Now determine if we can delete the record.
 228                  */
 229                 if (elm->base.delete_tid &&
 230                     elm->base.create_tid >= scan->beg_tid &&
 231                     elm->base.delete_tid <= scan->end_tid &&
 232                     elm->base.create_tid / scan->mod_tid ==
 233                     elm->base.delete_tid / scan->mod_tid) {
 234                         return(0);
 235                 }
 236         }
 237         return(-1);
 238 }
 239
 240 /*
 241  * Align the record to cover any gaps created through the deletion of
 242  * records within the pruning space.  If we were to just delete the records
 243  * there would be gaps which in turn would cause a snapshot that is NOT on
 244  * a pruning boundary to appear corrupt to the user.  Forcing alignment
 245  * of the create_tid and delete_tid for retained records 'reconnects'
 246  * the previously contiguous space, making it contiguous again after the
 247  * deletions.
 248  *
 249  * The use of a reverse iteration allows us to safely align the records and
 250  * related elements without creating temporary overlaps.  XXX we should
 251  * add ordering dependancies for record buffers to guarantee consistency
 252  * during recovery.
 253  */
 254 static int
 255 realign_prune(struct hammer_ioc_prune *prune,
 256               hammer_cursor_t cursor, int realign_cre, int realign_del)
 257 {
 258         hammer_btree_elm_t elm;
 259         hammer_tid_t delta;
 260         hammer_tid_t mod;
 261         hammer_tid_t tid;
 262         int error;
 263
 264         hammer_cursor_downgrade(cursor);
 265
 266         elm = &cursor->node->ondisk->elms[cursor->index];
 267         ++prune->stat_realignments;
 268
 269         /*
 270          * Align the create_tid.  By doing a reverse iteration we guarantee
 271          * that all records after our current record have already been
 272          * aligned, allowing us to safely correct the right-hand-boundary
 273          * (because no record to our right if otherwise exactly matching
 274          * will have a create_tid to the left of our aligned create_tid).
 275          *
 276          * Ordering is important here XXX but disk write ordering for
 277          * inter-cluster corrections is not currently guaranteed.
 278          */
 279         error = 0;
 280         if (realign_cre >= 0) {
 281                 mod = prune->elms[realign_cre].mod_tid;
 282                 delta = elm->leaf.base.create_tid % mod;
 283                 if (delta) {
 284                         tid = elm->leaf.base.create_tid - delta + mod;
 285
 286                         /* can EDEADLK */
 287                         error = hammer_btree_correct_rhb(cursor, tid + 1);
 288                         if (error == 0) {
 289                                 error = hammer_btree_extract(cursor,
 290                                                      HAMMER_CURSOR_GET_RECORD);
 291                         }
 292                         if (error == 0) {
 293                                 /* can EDEADLK */
 294                                 error = hammer_cursor_upgrade(cursor);
 295                         }
 296                         if (error == 0) {
 297                                 hammer_modify_buffer(cursor->record_buffer);
 298                                 cursor->record->base.base.create_tid = tid;
 299                                 hammer_modify_node(cursor->node);
 300                                 elm->leaf.base.create_tid = tid;
 301                         }
 302                 }
 303         }
 304
 305         /*
 306          * Align the delete_tid.  This only occurs if the record is historical
 307          * was deleted at some point.  Realigning the delete_tid does not
 308          * move the record within the B-Tree but may cause it to temporarily
 309          * overlap a record that has not yet been pruned.
 310          */
 311         if (error == 0 && realign_del >= 0) {
 312                 mod = prune->elms[realign_del].mod_tid;
 313                 delta = elm->leaf.base.delete_tid % mod;
 314                 hammer_modify_node(cursor->node);
 315                 if (delta) {
 316                         error = hammer_btree_extract(cursor,
 317                                                      HAMMER_CURSOR_GET_RECORD);
 318                         if (error == 0) {
 319                                 elm->leaf.base.delete_tid =
 320                                                 elm->leaf.base.delete_tid -
 321                                                 delta + mod;
 322                                 hammer_modify_buffer(cursor->record_buffer);
 323                                 cursor->record->base.base.delete_tid =
 324                                                 elm->leaf.base.delete_tid;
 325                         }
 326                 }
 327         }
 328         return (error);
 329 }
 330
 331 /*
 332  * Iterate through an object's inode or an object's records and record
 333  * modification TIDs.
 334  */
 335 static void add_history(hammer_inode_t ip, struct hammer_ioc_history *hist,
 336                         hammer_btree_elm_t elm);
 337
 338 static
 339 int
 340 hammer_ioc_gethistory(hammer_inode_t ip, struct hammer_ioc_history *hist)
 341 {
 342         struct hammer_cursor cursor;
 343         hammer_btree_elm_t elm;
 344         int error;
 345
 346         /*
 347          * Validate the structure and initialize for return.
 348          */
 349         if (hist->beg_tid > hist->end_tid)
 350                 return(EINVAL);
 351         if (hist->flags & HAMMER_IOC_HISTORY_ATKEY) {
 352                 if (hist->key > hist->nxt_key)
 353                         return(EINVAL);
 354         }
 355
 356         hist->obj_id = ip->obj_id;
 357         hist->count = 0;
 358         hist->nxt_tid = hist->end_tid;
 359         hist->flags &= ~HAMMER_IOC_HISTORY_NEXT_TID;
 360         hist->flags &= ~HAMMER_IOC_HISTORY_NEXT_KEY;
 361         hist->flags &= ~HAMMER_IOC_HISTORY_EOF;
 362         hist->flags &= ~HAMMER_IOC_HISTORY_UNSYNCED;
 363         if ((ip->flags & HAMMER_INODE_MODMASK) & ~HAMMER_INODE_ITIMES)
 364                 hist->flags |= HAMMER_IOC_HISTORY_UNSYNCED;
 365
 366         /*
 367          * Setup the cursor.  We can't handle undeletable records
 368          * (create_tid of 0) at the moment.  A create_tid of 0 has
 369          * a special meaning and cannot be specified in the cursor.
 370          */
 371         error = hammer_init_cursor_hmp(&cursor, &ip->cache[0], ip->hmp);
 372         if (error) {
 373                 hammer_done_cursor(&cursor);
 374                 return(error);
 375         }
 376
 377         cursor.key_beg.obj_id = hist->obj_id;
 378         cursor.key_beg.create_tid = hist->beg_tid;
 379         cursor.key_beg.delete_tid = 0;
 380         cursor.key_beg.obj_type = 0;
 381         if (cursor.key_beg.create_tid == HAMMER_MIN_TID)
 382                 cursor.key_beg.create_tid = 1;
 383
 384         cursor.key_end.obj_id = hist->obj_id;
 385         cursor.key_end.create_tid = hist->end_tid;
 386         cursor.key_end.delete_tid = 0;
 387         cursor.key_end.obj_type = 0;
 388
 389         cursor.flags |= HAMMER_CURSOR_END_EXCLUSIVE;
 390
 391         if (hist->flags & HAMMER_IOC_HISTORY_ATKEY) {
 392                 /*
 393                  * key-range within the file.  For a regular file the
 394                  * on-disk key represents BASE+LEN, not BASE, so the
 395                  * first possible record containing the offset 'key'
 396                  * has an on-disk key of (key + 1).
 397                  */
 398                 cursor.key_beg.key = hist->key;
 399                 cursor.key_end.key = HAMMER_MAX_KEY;
 400
 401                 switch(ip->ino_rec.base.base.obj_type) {
 402                 case HAMMER_OBJTYPE_REGFILE:
 403                         ++cursor.key_beg.key;
 404                         cursor.key_beg.rec_type = HAMMER_RECTYPE_DATA;
 405                         break;
 406                 case HAMMER_OBJTYPE_DIRECTORY:
 407                         cursor.key_beg.rec_type = HAMMER_RECTYPE_DIRENTRY;
 408                         break;
 409                 case HAMMER_OBJTYPE_DBFILE:
 410                         cursor.key_beg.rec_type = HAMMER_RECTYPE_DB;
 411                         break;
 412                 default:
 413                         error = EINVAL;
 414                         break;
 415                 }
 416                 cursor.key_end.rec_type = cursor.key_beg.rec_type;
 417         } else {
 418                 /*
 419                  * The inode itself.
 420                  */
 421                 cursor.key_beg.key = 0;
 422                 cursor.key_end.key = 0;
 423                 cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE;
 424                 cursor.key_end.rec_type = HAMMER_RECTYPE_INODE;
 425         }
 426
 427         error = hammer_btree_first(&cursor);
 428         while (error == 0) {
 429                 elm = &cursor.node->ondisk->elms[cursor.index];
 430
 431                 add_history(ip, hist, elm);
 432                 if (hist->flags & (HAMMER_IOC_HISTORY_NEXT_TID |
 433                                   HAMMER_IOC_HISTORY_NEXT_KEY |
 434                                   HAMMER_IOC_HISTORY_EOF)) {
 435                         break;
 436                 }
 437                 error = hammer_btree_iterate(&cursor);
 438         }
 439         if (error == ENOENT) {
 440                 hist->flags |= HAMMER_IOC_HISTORY_EOF;
 441                 error = 0;
 442         }
 443         hammer_done_cursor(&cursor);
 444         return(error);
 445 }
 446
 447 /*
 448  * Add the scanned element to the ioctl return structure.  Some special
 449  * casing is required for regular files to accomodate how data ranges are
 450  * stored on-disk.
 451  */
 452 static void
 453 add_history(hammer_inode_t ip, struct hammer_ioc_history *hist,
 454             hammer_btree_elm_t elm)
 455 {
 456         if (elm->base.btype != HAMMER_BTREE_TYPE_RECORD)
 457                 return;
 458         if ((hist->flags & HAMMER_IOC_HISTORY_ATKEY) &&
 459             ip->ino_rec.base.base.obj_type == HAMMER_OBJTYPE_REGFILE) {
 460                 /*
 461                  * Adjust nxt_key
 462                  */
 463                 if (hist->nxt_key > elm->leaf.base.key - elm->leaf.data_len &&
 464                     hist->key < elm->leaf.base.key - elm->leaf.data_len) {
 465                         hist->nxt_key = elm->leaf.base.key - elm->leaf.data_len;
 466                 }
 467                 if (hist->nxt_key > elm->leaf.base.key)
 468                         hist->nxt_key = elm->leaf.base.key;
 469
 470                 /*
 471                  * Record is beyond MAXPHYS, there won't be any more records
 472                  * in the iteration covering the requested offset (key).
 473                  */
 474                 if (elm->leaf.base.key >= MAXPHYS &&
 475                     elm->leaf.base.key - MAXPHYS > hist->key) {
 476                         hist->flags |= HAMMER_IOC_HISTORY_NEXT_KEY;
 477                 }
 478
 479                 /*
 480                  * Data-range of record does not cover the key.
 481                  */
 482                 if (elm->leaf.base.key - elm->leaf.data_len > hist->key)
 483                         return;
 484
 485         } else if (hist->flags & HAMMER_IOC_HISTORY_ATKEY) {
 486                 /*
 487                  * Adjust nxt_key
 488                  */
 489                 if (hist->nxt_key > elm->leaf.base.key &&
 490                     hist->key < elm->leaf.base.key) {
 491                         hist->nxt_key = elm->leaf.base.key;
 492                 }
 493
 494                 /*
 495                  * Record is beyond the requested key.
 496                  */
 497                 if (elm->leaf.base.key > hist->key)
 498                         hist->flags |= HAMMER_IOC_HISTORY_NEXT_KEY;
 499         }
 500
 501         /*
 502          * Add create_tid if it is in-bounds.
 503          */
 504         if ((hist->count == 0 ||
 505              elm->leaf.base.create_tid != hist->tid_ary[hist->count - 1]) &&
 506             elm->leaf.base.create_tid >= hist->beg_tid &&
 507             elm->leaf.base.create_tid < hist->end_tid) {
 508                 if (hist->count == HAMMER_MAX_HISTORY_ELMS) {
 509                         hist->nxt_tid = elm->leaf.base.create_tid;
 510                         hist->flags |= HAMMER_IOC_HISTORY_NEXT_TID;
 511                         return;
 512                 }
 513                 hist->tid_ary[hist->count++] = elm->leaf.base.create_tid;
 514         }
 515
 516         /*
 517          * Add delete_tid if it is in-bounds.  Note that different portions
 518          * of the history may have overlapping data ranges with different
 519          * delete_tid's.  If this case occurs the delete_tid may match the
 520          * create_tid of a following record.  XXX
 521          *
 522          *      [        ]
 523          *            [     ]
 524          */
 525         if (elm->leaf.base.delete_tid &&
 526             elm->leaf.base.delete_tid >= hist->beg_tid &&
 527             elm->leaf.base.delete_tid < hist->end_tid) {
 528                 if (hist->count == HAMMER_MAX_HISTORY_ELMS) {
 529                         hist->nxt_tid = elm->leaf.base.delete_tid;
 530                         hist->flags |= HAMMER_IOC_HISTORY_NEXT_TID;
 531                         return;
 532                 }
 533                 hist->tid_ary[hist->count++] = elm->leaf.base.delete_tid;
 534         }
 535 }
 536