fs/ocfs2/extent_map.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * extent_map.c
   5  *
   6  * Block/Cluster mapping functions
   7  *
   8  * Copyright (C) 2004 Oracle.  All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public
  12  * License, version 2,  as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public
  20  * License along with this program; if not, write to the
  21  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22  * Boston, MA 021110-1307, USA.
  23  */
  24
  25 #include <linux/fs.h>
  26 #include <linux/init.h>
  27 #include <linux/types.h>
  28 #include <linux/fiemap.h>
  29
  30 #define MLOG_MASK_PREFIX ML_EXTENT_MAP
  31 #include <cluster/masklog.h>
  32
  33 #include "ocfs2.h"
  34
  35 #include "alloc.h"
  36 #include "dlmglue.h"
  37 #include "extent_map.h"
  38 #include "inode.h"
  39 #include "super.h"
  40
  41 #include "buffer_head_io.h"
  42
  43 /*
  44  * The extent caching implementation is intentionally trivial.
  45  *
  46  * We only cache a small number of extents stored directly on the
  47  * inode, so linear order operations are acceptable. If we ever want
  48  * to increase the size of the extent map, then these algorithms must
  49  * get smarter.
  50  */
  51
  52 void ocfs2_extent_map_init(struct inode *inode)
  53 {
  54         struct ocfs2_inode_info *oi = OCFS2_I(inode);
  55
  56         oi->ip_extent_map.em_num_items = 0;
  57         INIT_LIST_HEAD(&oi->ip_extent_map.em_list);
  58 }
  59
  60 static void __ocfs2_extent_map_lookup(struct ocfs2_extent_map *em,
  61                                       unsigned int cpos,
  62                                       struct ocfs2_extent_map_item **ret_emi)
  63 {
  64         unsigned int range;
  65         struct ocfs2_extent_map_item *emi;
  66
  67         *ret_emi = NULL;
  68
  69         list_for_each_entry(emi, &em->em_list, ei_list) {
  70                 range = emi->ei_cpos + emi->ei_clusters;
  71
  72                 if (cpos >= emi->ei_cpos && cpos < range) {
  73                         list_move(&emi->ei_list, &em->em_list);
  74
  75                         *ret_emi = emi;
  76                         break;
  77                 }
  78         }
  79 }
  80
  81 static int ocfs2_extent_map_lookup(struct inode *inode, unsigned int cpos,
  82                                    unsigned int *phys, unsigned int *len,
  83                                    unsigned int *flags)
  84 {
  85         unsigned int coff;
  86         struct ocfs2_inode_info *oi = OCFS2_I(inode);
  87         struct ocfs2_extent_map_item *emi;
  88
  89         spin_lock(&oi->ip_lock);
  90
  91         __ocfs2_extent_map_lookup(&oi->ip_extent_map, cpos, &emi);
  92         if (emi) {
  93                 coff = cpos - emi->ei_cpos;
  94                 *phys = emi->ei_phys + coff;
  95                 if (len)
  96                         *len = emi->ei_clusters - coff;
  97                 if (flags)
  98                         *flags = emi->ei_flags;
  99         }
 100
 101         spin_unlock(&oi->ip_lock);
 102
 103         if (emi == NULL)
 104                 return -ENOENT;
 105
 106         return 0;
 107 }
 108
 109 /*
 110  * Forget about all clusters equal to or greater than cpos.
 111  */
 112 void ocfs2_extent_map_trunc(struct inode *inode, unsigned int cpos)
 113 {
 114         struct ocfs2_extent_map_item *emi, *n;
 115         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 116         struct ocfs2_extent_map *em = &oi->ip_extent_map;
 117         LIST_HEAD(tmp_list);
 118         unsigned int range;
 119
 120         spin_lock(&oi->ip_lock);
 121         list_for_each_entry_safe(emi, n, &em->em_list, ei_list) {
 122                 if (emi->ei_cpos >= cpos) {
 123                         /* Full truncate of this record. */
 124                         list_move(&emi->ei_list, &tmp_list);
 125                         BUG_ON(em->em_num_items == 0);
 126                         em->em_num_items--;
 127                         continue;
 128                 }
 129
 130                 range = emi->ei_cpos + emi->ei_clusters;
 131                 if (range > cpos) {
 132                         /* Partial truncate */
 133                         emi->ei_clusters = cpos - emi->ei_cpos;
 134                 }
 135         }
 136         spin_unlock(&oi->ip_lock);
 137
 138         list_for_each_entry_safe(emi, n, &tmp_list, ei_list) {
 139                 list_del(&emi->ei_list);
 140                 kfree(emi);
 141         }
 142 }
 143
 144 /*
 145  * Is any part of emi2 contained within emi1
 146  */
 147 static int ocfs2_ei_is_contained(struct ocfs2_extent_map_item *emi1,
 148                                  struct ocfs2_extent_map_item *emi2)
 149 {
 150         unsigned int range1, range2;
 151
 152         /*
 153          * Check if logical start of emi2 is inside emi1
 154          */
 155         range1 = emi1->ei_cpos + emi1->ei_clusters;
 156         if (emi2->ei_cpos >= emi1->ei_cpos && emi2->ei_cpos < range1)
 157                 return 1;
 158
 159         /*
 160          * Check if logical end of emi2 is inside emi1
 161          */
 162         range2 = emi2->ei_cpos + emi2->ei_clusters;
 163         if (range2 > emi1->ei_cpos && range2 <= range1)
 164                 return 1;
 165
 166         return 0;
 167 }
 168
 169 static void ocfs2_copy_emi_fields(struct ocfs2_extent_map_item *dest,
 170                                   struct ocfs2_extent_map_item *src)
 171 {
 172         dest->ei_cpos = src->ei_cpos;
 173         dest->ei_phys = src->ei_phys;
 174         dest->ei_clusters = src->ei_clusters;
 175         dest->ei_flags = src->ei_flags;
 176 }
 177
 178 /*
 179  * Try to merge emi with ins. Returns 1 if merge succeeds, zero
 180  * otherwise.
 181  */
 182 static int ocfs2_try_to_merge_extent_map(struct ocfs2_extent_map_item *emi,
 183                                          struct ocfs2_extent_map_item *ins)
 184 {
 185         /*
 186          * Handle contiguousness
 187          */
 188         if (ins->ei_phys == (emi->ei_phys + emi->ei_clusters) &&
 189             ins->ei_cpos == (emi->ei_cpos + emi->ei_clusters) &&
 190             ins->ei_flags == emi->ei_flags) {
 191                 emi->ei_clusters += ins->ei_clusters;
 192                 return 1;
 193         } else if ((ins->ei_phys + ins->ei_clusters) == emi->ei_phys &&
 194                    (ins->ei_cpos + ins->ei_clusters) == emi->ei_phys &&
 195                    ins->ei_flags == emi->ei_flags) {
 196                 emi->ei_phys = ins->ei_phys;
 197                 emi->ei_cpos = ins->ei_cpos;
 198                 emi->ei_clusters += ins->ei_clusters;
 199                 return 1;
 200         }
 201
 202         /*
 203          * Overlapping extents - this shouldn't happen unless we've
 204          * split an extent to change it's flags. That is exceedingly
 205          * rare, so there's no sense in trying to optimize it yet.
 206          */
 207         if (ocfs2_ei_is_contained(emi, ins) ||
 208             ocfs2_ei_is_contained(ins, emi)) {
 209                 ocfs2_copy_emi_fields(emi, ins);
 210                 return 1;
 211         }
 212
 213         /* No merge was possible. */
 214         return 0;
 215 }
 216
 217 /*
 218  * In order to reduce complexity on the caller, this insert function
 219  * is intentionally liberal in what it will accept.
 220  *
 221  * The only rule is that the truncate call *must* be used whenever
 222  * records have been deleted. This avoids inserting overlapping
 223  * records with different physical mappings.
 224  */
 225 void ocfs2_extent_map_insert_rec(struct inode *inode,
 226                                  struct ocfs2_extent_rec *rec)
 227 {
 228         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 229         struct ocfs2_extent_map *em = &oi->ip_extent_map;
 230         struct ocfs2_extent_map_item *emi, *new_emi = NULL;
 231         struct ocfs2_extent_map_item ins;
 232
 233         ins.ei_cpos = le32_to_cpu(rec->e_cpos);
 234         ins.ei_phys = ocfs2_blocks_to_clusters(inode->i_sb,
 235                                                le64_to_cpu(rec->e_blkno));
 236         ins.ei_clusters = le16_to_cpu(rec->e_leaf_clusters);
 237         ins.ei_flags = rec->e_flags;
 238
 239 search:
 240         spin_lock(&oi->ip_lock);
 241
 242         list_for_each_entry(emi, &em->em_list, ei_list) {
 243                 if (ocfs2_try_to_merge_extent_map(emi, &ins)) {
 244                         list_move(&emi->ei_list, &em->em_list);
 245                         spin_unlock(&oi->ip_lock);
 246                         goto out;
 247                 }
 248         }
 249
 250         /*
 251          * No item could be merged.
 252          *
 253          * Either allocate and add a new item, or overwrite the last recently
 254          * inserted.
 255          */
 256
 257         if (em->em_num_items < OCFS2_MAX_EXTENT_MAP_ITEMS) {
 258                 if (new_emi == NULL) {
 259                         spin_unlock(&oi->ip_lock);
 260
 261                         new_emi = kmalloc(sizeof(*new_emi), GFP_NOFS);
 262                         if (new_emi == NULL)
 263                                 goto out;
 264
 265                         goto search;
 266                 }
 267
 268                 ocfs2_copy_emi_fields(new_emi, &ins);
 269                 list_add(&new_emi->ei_list, &em->em_list);
 270                 em->em_num_items++;
 271                 new_emi = NULL;
 272         } else {
 273                 BUG_ON(list_empty(&em->em_list) || em->em_num_items == 0);
 274                 emi = list_entry(em->em_list.prev,
 275                                  struct ocfs2_extent_map_item, ei_list);
 276                 list_move(&emi->ei_list, &em->em_list);
 277                 ocfs2_copy_emi_fields(emi, &ins);
 278         }
 279
 280         spin_unlock(&oi->ip_lock);
 281
 282 out:
 283         if (new_emi)
 284                 kfree(new_emi);
 285 }
 286
 287 static int ocfs2_last_eb_is_empty(struct inode *inode,
 288                                   struct ocfs2_dinode *di)
 289 {
 290         int ret, next_free;
 291         u64 last_eb_blk = le64_to_cpu(di->i_last_eb_blk);
 292         struct buffer_head *eb_bh = NULL;
 293         struct ocfs2_extent_block *eb;
 294         struct ocfs2_extent_list *el;
 295
 296         ret = ocfs2_read_block(inode, last_eb_blk, &eb_bh);
 297         if (ret) {
 298                 mlog_errno(ret);
 299                 goto out;
 300         }
 301
 302         eb = (struct ocfs2_extent_block *) eb_bh->b_data;
 303         el = &eb->h_list;
 304
 305         if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
 306                 ret = -EROFS;
 307                 OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
 308                 goto out;
 309         }
 310
 311         if (el->l_tree_depth) {
 312                 ocfs2_error(inode->i_sb,
 313                             "Inode %lu has non zero tree depth in "
 314                             "leaf block %llu\n", inode->i_ino,
 315                             (unsigned long long)eb_bh->b_blocknr);
 316                 ret = -EROFS;
 317                 goto out;
 318         }
 319
 320         next_free = le16_to_cpu(el->l_next_free_rec);
 321
 322         if (next_free == 0 ||
 323             (next_free == 1 && ocfs2_is_empty_extent(&el->l_recs[0])))
 324                 ret = 1;
 325
 326 out:
 327         brelse(eb_bh);
 328         return ret;
 329 }
 330
 331 /*
 332  * Return the 1st index within el which contains an extent start
 333  * larger than v_cluster.
 334  */
 335 static int ocfs2_search_for_hole_index(struct ocfs2_extent_list *el,
 336                                        u32 v_cluster)
 337 {
 338         int i;
 339         struct ocfs2_extent_rec *rec;
 340
 341         for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 342                 rec = &el->l_recs[i];
 343
 344                 if (v_cluster < le32_to_cpu(rec->e_cpos))
 345                         break;
 346         }
 347
 348         return i;
 349 }
 350
 351 /*
 352  * Figure out the size of a hole which starts at v_cluster within the given
 353  * extent list.
 354  *
 355  * If there is no more allocation past v_cluster, we return the maximum
 356  * cluster size minus v_cluster.
 357  *
 358  * If we have in-inode extents, then el points to the dinode list and
 359  * eb_bh is NULL. Otherwise, eb_bh should point to the extent block
 360  * containing el.
 361  */
 362 static int ocfs2_figure_hole_clusters(struct inode *inode,
 363                                       struct ocfs2_extent_list *el,
 364                                       struct buffer_head *eb_bh,
 365                                       u32 v_cluster,
 366                                       u32 *num_clusters)
 367 {
 368         int ret, i;
 369         struct buffer_head *next_eb_bh = NULL;
 370         struct ocfs2_extent_block *eb, *next_eb;
 371
 372         i = ocfs2_search_for_hole_index(el, v_cluster);
 373
 374         if (i == le16_to_cpu(el->l_next_free_rec) && eb_bh) {
 375                 eb = (struct ocfs2_extent_block *)eb_bh->b_data;
 376
 377                 /*
 378                  * Check the next leaf for any extents.
 379                  */
 380
 381                 if (le64_to_cpu(eb->h_next_leaf_blk) == 0ULL)
 382                         goto no_more_extents;
 383
 384                 ret = ocfs2_read_block(inode,
 385                                        le64_to_cpu(eb->h_next_leaf_blk),
 386                                        &next_eb_bh);
 387                 if (ret) {
 388                         mlog_errno(ret);
 389                         goto out;
 390                 }
 391                 next_eb = (struct ocfs2_extent_block *)next_eb_bh->b_data;
 392
 393                 if (!OCFS2_IS_VALID_EXTENT_BLOCK(next_eb)) {
 394                         ret = -EROFS;
 395                         OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, next_eb);
 396                         goto out;
 397                 }
 398
 399                 el = &next_eb->h_list;
 400
 401                 i = ocfs2_search_for_hole_index(el, v_cluster);
 402         }
 403
 404 no_more_extents:
 405         if (i == le16_to_cpu(el->l_next_free_rec)) {
 406                 /*
 407                  * We're at the end of our existing allocation. Just
 408                  * return the maximum number of clusters we could
 409                  * possibly allocate.
 410                  */
 411                 *num_clusters = UINT_MAX - v_cluster;
 412         } else {
 413                 *num_clusters = le32_to_cpu(el->l_recs[i].e_cpos) - v_cluster;
 414         }
 415
 416         ret = 0;
 417 out:
 418         brelse(next_eb_bh);
 419         return ret;
 420 }
 421
 422 static int ocfs2_get_clusters_nocache(struct inode *inode,
 423                                       struct buffer_head *di_bh,
 424                                       u32 v_cluster, unsigned int *hole_len,
 425                                       struct ocfs2_extent_rec *ret_rec,
 426                                       unsigned int *is_last)
 427 {
 428         int i, ret, tree_height, len;
 429         struct ocfs2_dinode *di;
 430         struct ocfs2_extent_block *uninitialized_var(eb);
 431         struct ocfs2_extent_list *el;
 432         struct ocfs2_extent_rec *rec;
 433         struct buffer_head *eb_bh = NULL;
 434
 435         memset(ret_rec, 0, sizeof(*ret_rec));
 436         if (is_last)
 437                 *is_last = 0;
 438
 439         di = (struct ocfs2_dinode *) di_bh->b_data;
 440         el = &di->id2.i_list;
 441         tree_height = le16_to_cpu(el->l_tree_depth);
 442
 443         if (tree_height > 0) {
 444                 ret = ocfs2_find_leaf(inode, el, v_cluster, &eb_bh);
 445                 if (ret) {
 446                         mlog_errno(ret);
 447                         goto out;
 448                 }
 449
 450                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
 451                 el = &eb->h_list;
 452
 453                 if (el->l_tree_depth) {
 454                         ocfs2_error(inode->i_sb,
 455                                     "Inode %lu has non zero tree depth in "
 456                                     "leaf block %llu\n", inode->i_ino,
 457                                     (unsigned long long)eb_bh->b_blocknr);
 458                         ret = -EROFS;
 459                         goto out;
 460                 }
 461         }
 462
 463         i = ocfs2_search_extent_list(el, v_cluster);
 464         if (i == -1) {
 465                 /*
 466                  * Holes can be larger than the maximum size of an
 467                  * extent, so we return their lengths in a seperate
 468                  * field.
 469                  */
 470                 if (hole_len) {
 471                         ret = ocfs2_figure_hole_clusters(inode, el, eb_bh,
 472                                                          v_cluster, &len);
 473                         if (ret) {
 474                                 mlog_errno(ret);
 475                                 goto out;
 476                         }
 477
 478                         *hole_len = len;
 479                 }
 480                 goto out_hole;
 481         }
 482
 483         rec = &el->l_recs[i];
 484
 485         BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos));
 486
 487         if (!rec->e_blkno) {
 488                 ocfs2_error(inode->i_sb, "Inode %lu has bad extent "
 489                             "record (%u, %u, 0)", inode->i_ino,
 490                             le32_to_cpu(rec->e_cpos),
 491                             ocfs2_rec_clusters(el, rec));
 492                 ret = -EROFS;
 493                 goto out;
 494         }
 495
 496         *ret_rec = *rec;
 497
 498         /*
 499          * Checking for last extent is potentially expensive - we
 500          * might have to look at the next leaf over to see if it's
 501          * empty.
 502          *
 503          * The first two checks are to see whether the caller even
 504          * cares for this information, and if the extent is at least
 505          * the last in it's list.
 506          *
 507          * If those hold true, then the extent is last if any of the
 508          * additional conditions hold true:
 509          *  - Extent list is in-inode
 510          *  - Extent list is right-most
 511          *  - Extent list is 2nd to rightmost, with empty right-most
 512          */
 513         if (is_last) {
 514                 if (i == (le16_to_cpu(el->l_next_free_rec) - 1)) {
 515                         if (tree_height == 0)
 516                                 *is_last = 1;
 517                         else if (eb->h_blkno == di->i_last_eb_blk)
 518                                 *is_last = 1;
 519                         else if (eb->h_next_leaf_blk == di->i_last_eb_blk) {
 520                                 ret = ocfs2_last_eb_is_empty(inode, di);
 521                                 if (ret < 0) {
 522                                         mlog_errno(ret);
 523                                         goto out;
 524                                 }
 525                                 if (ret == 1)
 526                                         *is_last = 1;
 527                         }
 528                 }
 529         }
 530
 531 out_hole:
 532         ret = 0;
 533 out:
 534         brelse(eb_bh);
 535         return ret;
 536 }
 537
 538 static void ocfs2_relative_extent_offsets(struct super_block *sb,
 539                                           u32 v_cluster,
 540                                           struct ocfs2_extent_rec *rec,
 541                                           u32 *p_cluster, u32 *num_clusters)
 542
 543 {
 544         u32 coff = v_cluster - le32_to_cpu(rec->e_cpos);
 545
 546         *p_cluster = ocfs2_blocks_to_clusters(sb, le64_to_cpu(rec->e_blkno));
 547         *p_cluster = *p_cluster + coff;
 548
 549         if (num_clusters)
 550                 *num_clusters = le16_to_cpu(rec->e_leaf_clusters) - coff;
 551 }
 552
 553 int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster,
 554                              u32 *p_cluster, u32 *num_clusters,
 555                              struct ocfs2_extent_list *el)
 556 {
 557         int ret = 0, i;
 558         struct buffer_head *eb_bh = NULL;
 559         struct ocfs2_extent_block *eb;
 560         struct ocfs2_extent_rec *rec;
 561         u32 coff;
 562
 563         if (el->l_tree_depth) {
 564                 ret = ocfs2_find_leaf(inode, el, v_cluster, &eb_bh);
 565                 if (ret) {
 566                         mlog_errno(ret);
 567                         goto out;
 568                 }
 569
 570                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
 571                 el = &eb->h_list;
 572
 573                 if (el->l_tree_depth) {
 574                         ocfs2_error(inode->i_sb,
 575                                     "Inode %lu has non zero tree depth in "
 576                                     "xattr leaf block %llu\n", inode->i_ino,
 577                                     (unsigned long long)eb_bh->b_blocknr);
 578                         ret = -EROFS;
 579                         goto out;
 580                 }
 581         }
 582
 583         i = ocfs2_search_extent_list(el, v_cluster);
 584         if (i == -1) {
 585                 ret = -EROFS;
 586                 mlog_errno(ret);
 587                 goto out;
 588         } else {
 589                 rec = &el->l_recs[i];
 590                 BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos));
 591
 592                 if (!rec->e_blkno) {
 593                         ocfs2_error(inode->i_sb, "Inode %lu has bad extent "
 594                                     "record (%u, %u, 0) in xattr", inode->i_ino,
 595                                     le32_to_cpu(rec->e_cpos),
 596                                     ocfs2_rec_clusters(el, rec));
 597                         ret = -EROFS;
 598                         goto out;
 599                 }
 600                 coff = v_cluster - le32_to_cpu(rec->e_cpos);
 601                 *p_cluster = ocfs2_blocks_to_clusters(inode->i_sb,
 602                                                     le64_to_cpu(rec->e_blkno));
 603                 *p_cluster = *p_cluster + coff;
 604                 if (num_clusters)
 605                         *num_clusters = ocfs2_rec_clusters(el, rec) - coff;
 606         }
 607 out:
 608         if (eb_bh)
 609                 brelse(eb_bh);
 610         return ret;
 611 }
 612
 613 int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
 614                        u32 *p_cluster, u32 *num_clusters,
 615                        unsigned int *extent_flags)
 616 {
 617         int ret;
 618         unsigned int uninitialized_var(hole_len), flags = 0;
 619         struct buffer_head *di_bh = NULL;
 620         struct ocfs2_extent_rec rec;
 621
 622         if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
 623                 ret = -ERANGE;
 624                 mlog_errno(ret);
 625                 goto out;
 626         }
 627
 628         ret = ocfs2_extent_map_lookup(inode, v_cluster, p_cluster,
 629                                       num_clusters, extent_flags);
 630         if (ret == 0)
 631                 goto out;
 632
 633         ret = ocfs2_read_block(inode, OCFS2_I(inode)->ip_blkno, &di_bh);
 634         if (ret) {
 635                 mlog_errno(ret);
 636                 goto out;
 637         }
 638
 639         ret = ocfs2_get_clusters_nocache(inode, di_bh, v_cluster, &hole_len,
 640                                          &rec, NULL);
 641         if (ret) {
 642                 mlog_errno(ret);
 643                 goto out;
 644         }
 645
 646         if (rec.e_blkno == 0ULL) {
 647                 /*
 648                  * A hole was found. Return some canned values that
 649                  * callers can key on. If asked for, num_clusters will
 650                  * be populated with the size of the hole.
 651                  */
 652                 *p_cluster = 0;
 653                 if (num_clusters) {
 654                         *num_clusters = hole_len;
 655                 }
 656         } else {
 657                 ocfs2_relative_extent_offsets(inode->i_sb, v_cluster, &rec,
 658                                               p_cluster, num_clusters);
 659                 flags = rec.e_flags;
 660
 661                 ocfs2_extent_map_insert_rec(inode, &rec);
 662         }
 663
 664         if (extent_flags)
 665                 *extent_flags = flags;
 666
 667 out:
 668         brelse(di_bh);
 669         return ret;
 670 }
 671
 672 /*
 673  * This expects alloc_sem to be held. The allocation cannot change at
 674  * all while the map is in the process of being updated.
 675  */
 676 int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
 677                                 u64 *ret_count, unsigned int *extent_flags)
 678 {
 679         int ret;
 680         int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
 681         u32 cpos, num_clusters, p_cluster;
 682         u64 boff = 0;
 683
 684         cpos = ocfs2_blocks_to_clusters(inode->i_sb, v_blkno);
 685
 686         ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters,
 687                                  extent_flags);
 688         if (ret) {
 689                 mlog_errno(ret);
 690                 goto out;
 691         }
 692
 693         /*
 694          * p_cluster == 0 indicates a hole.
 695          */
 696         if (p_cluster) {
 697                 boff = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);
 698                 boff += (v_blkno & (u64)(bpc - 1));
 699         }
 700
 701         *p_blkno = boff;
 702
 703         if (ret_count) {
 704                 *ret_count = ocfs2_clusters_to_blocks(inode->i_sb, num_clusters);
 705                 *ret_count -= v_blkno & (u64)(bpc - 1);
 706         }
 707
 708 out:
 709         return ret;
 710 }
 711
 712 static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
 713                                struct fiemap_extent_info *fieinfo,
 714                                u64 map_start)
 715 {
 716         int ret;
 717         unsigned int id_count;
 718         struct ocfs2_dinode *di;
 719         u64 phys;
 720         u32 flags = FIEMAP_EXTENT_DATA_INLINE|FIEMAP_EXTENT_LAST;
 721         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 722
 723         di = (struct ocfs2_dinode *)di_bh->b_data;
 724         id_count = le16_to_cpu(di->id2.i_data.id_count);
 725
 726         if (map_start < id_count) {
 727                 phys = oi->ip_blkno << inode->i_sb->s_blocksize_bits;
 728                 phys += offsetof(struct ocfs2_dinode, id2.i_data.id_data);
 729
 730                 ret = fiemap_fill_next_extent(fieinfo, 0, phys, id_count,
 731                                               flags);
 732                 if (ret < 0)
 733                         return ret;
 734         }
 735
 736         return 0;
 737 }
 738
 739 #define OCFS2_FIEMAP_FLAGS      (FIEMAP_FLAG_SYNC)
 740
 741 int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 742                  u64 map_start, u64 map_len)
 743 {
 744         int ret, is_last;
 745         u32 mapping_end, cpos;
 746         unsigned int hole_size;
 747         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 748         u64 len_bytes, phys_bytes, virt_bytes;
 749         struct buffer_head *di_bh = NULL;
 750         struct ocfs2_extent_rec rec;
 751
 752         ret = fiemap_check_flags(fieinfo, OCFS2_FIEMAP_FLAGS);
 753         if (ret)
 754                 return ret;
 755
 756         ret = ocfs2_inode_lock(inode, &di_bh, 0);
 757         if (ret) {
 758                 mlog_errno(ret);
 759                 goto out;
 760         }
 761
 762         down_read(&OCFS2_I(inode)->ip_alloc_sem);
 763
 764         /*
 765          * Handle inline-data separately.
 766          */
 767         if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
 768                 ret = ocfs2_fiemap_inline(inode, di_bh, fieinfo, map_start);
 769                 goto out_unlock;
 770         }
 771
 772         cpos = map_start >> osb->s_clustersize_bits;
 773         mapping_end = ocfs2_clusters_for_bytes(inode->i_sb,
 774                                                map_start + map_len);
 775         mapping_end -= cpos;
 776         is_last = 0;
 777         while (cpos < mapping_end && !is_last) {
 778                 u32 fe_flags;
 779
 780                 ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos,
 781                                                  &hole_size, &rec, &is_last);
 782                 if (ret) {
 783                         mlog_errno(ret);
 784                         goto out;
 785                 }
 786
 787                 if (rec.e_blkno == 0ULL) {
 788                         cpos += hole_size;
 789                         continue;
 790                 }
 791
 792                 fe_flags = 0;
 793                 if (rec.e_flags & OCFS2_EXT_UNWRITTEN)
 794                         fe_flags |= FIEMAP_EXTENT_UNWRITTEN;
 795                 if (is_last)
 796                         fe_flags |= FIEMAP_EXTENT_LAST;
 797                 len_bytes = (u64)le16_to_cpu(rec.e_leaf_clusters) << osb->s_clustersize_bits;
 798                 phys_bytes = le64_to_cpu(rec.e_blkno) << osb->sb->s_blocksize_bits;
 799                 virt_bytes = (u64)le32_to_cpu(rec.e_cpos) << osb->s_clustersize_bits;
 800
 801                 ret = fiemap_fill_next_extent(fieinfo, virt_bytes, phys_bytes,
 802                                               len_bytes, fe_flags);
 803                 if (ret)
 804                         break;
 805
 806                 cpos = le32_to_cpu(rec.e_cpos)+ le16_to_cpu(rec.e_leaf_clusters);
 807         }
 808
 809         if (ret > 0)
 810                 ret = 0;
 811
 812 out_unlock:
 813         brelse(di_bh);
 814
 815         up_read(&OCFS2_I(inode)->ip_alloc_sem);
 816
 817         ocfs2_inode_unlock(inode, 0);
 818 out:
 819
 820         return ret;
 821 }