fs/ext4/extents.c

   1 /*
   2  * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
   3  * Written by Alex Tomas <alex@clusterfs.com>
   4  *
   5  * Architecture independence:
   6  *   Copyright (c) 2005, Bull S.A.
   7  *   Written by Pierre Peiffer <pierre.peiffer@bull.net>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public Licens
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
  21  */
  22
  23 /*
  24  * Extents support for EXT4
  25  *
  26  * TODO:
  27  *   - ext4*_error() should be used in some situations
  28  *   - analyze all BUG()/BUG_ON(), use -EIO where appropriate
  29  *   - smart tree reduction
  30  */
  31
  32 #include <linux/fs.h>
  33 #include <linux/time.h>
  34 #include <linux/jbd2.h>
  35 #include <linux/highuid.h>
  36 #include <linux/pagemap.h>
  37 #include <linux/quotaops.h>
  38 #include <linux/string.h>
  39 #include <linux/slab.h>
  40 #include <linux/falloc.h>
  41 #include <asm/uaccess.h>
  42 #include <linux/fiemap.h>
  43 #include "ext4_jbd2.h"
  44 #include "ext4_extents.h"
  45 #include "xattr.h"
  46
  47 #include <trace/events/ext4.h>
  48
  49 /*
  50  * used by extent splitting.
  51  */
  52 #define EXT4_EXT_MAY_ZEROOUT    0x1  /* safe to zeroout if split fails \
  53                                         due to ENOSPC */
  54 #define EXT4_EXT_MARK_UNINIT1   0x2  /* mark first half uninitialized */
  55 #define EXT4_EXT_MARK_UNINIT2   0x4  /* mark second half uninitialized */
  56
  57 #define EXT4_EXT_DATA_VALID1    0x8  /* first half contains valid data */
  58 #define EXT4_EXT_DATA_VALID2    0x10 /* second half contains valid data */
  59
  60 static __le32 ext4_extent_block_csum(struct inode *inode,
  61                                      struct ext4_extent_header *eh)
  62 {
  63         struct ext4_inode_info *ei = EXT4_I(inode);
  64         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  65         __u32 csum;
  66
  67         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
  68                            EXT4_EXTENT_TAIL_OFFSET(eh));
  69         return cpu_to_le32(csum);
  70 }
  71
  72 static int ext4_extent_block_csum_verify(struct inode *inode,
  73                                          struct ext4_extent_header *eh)
  74 {
  75         struct ext4_extent_tail *et;
  76
  77         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
  78                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
  79                 return 1;
  80
  81         et = find_ext4_extent_tail(eh);
  82         if (et->et_checksum != ext4_extent_block_csum(inode, eh))
  83                 return 0;
  84         return 1;
  85 }
  86
  87 static void ext4_extent_block_csum_set(struct inode *inode,
  88                                        struct ext4_extent_header *eh)
  89 {
  90         struct ext4_extent_tail *et;
  91
  92         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
  93                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
  94                 return;
  95
  96         et = find_ext4_extent_tail(eh);
  97         et->et_checksum = ext4_extent_block_csum(inode, eh);
  98 }
  99
 100 static int ext4_split_extent(handle_t *handle,
 101                                 struct inode *inode,
 102                                 struct ext4_ext_path *path,
 103                                 struct ext4_map_blocks *map,
 104                                 int split_flag,
 105                                 int flags);
 106
 107 static int ext4_split_extent_at(handle_t *handle,
 108                              struct inode *inode,
 109                              struct ext4_ext_path *path,
 110                              ext4_lblk_t split,
 111                              int split_flag,
 112                              int flags);
 113
 114 static int ext4_find_delayed_extent(struct inode *inode,
 115                                     struct extent_status *newes);
 116
 117 static int ext4_ext_truncate_extend_restart(handle_t *handle,
 118                                             struct inode *inode,
 119                                             int needed)
 120 {
 121         int err;
 122
 123         if (!ext4_handle_valid(handle))
 124                 return 0;
 125         if (handle->h_buffer_credits > needed)
 126                 return 0;
 127         err = ext4_journal_extend(handle, needed);
 128         if (err <= 0)
 129                 return err;
 130         err = ext4_truncate_restart_trans(handle, inode, needed);
 131         if (err == 0)
 132                 err = -EAGAIN;
 133
 134         return err;
 135 }
 136
 137 /*
 138  * could return:
 139  *  - EROFS
 140  *  - ENOMEM
 141  */
 142 static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
 143                                 struct ext4_ext_path *path)
 144 {
 145         if (path->p_bh) {
 146                 /* path points to block */
 147                 return ext4_journal_get_write_access(handle, path->p_bh);
 148         }
 149         /* path points to leaf/index in inode body */
 150         /* we use in-core data, no need to protect them */
 151         return 0;
 152 }
 153
 154 /*
 155  * could return:
 156  *  - EROFS
 157  *  - ENOMEM
 158  *  - EIO
 159  */
 160 int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle,
 161                      struct inode *inode, struct ext4_ext_path *path)
 162 {
 163         int err;
 164         if (path->p_bh) {
 165                 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
 166                 /* path points to block */
 167                 err = __ext4_handle_dirty_metadata(where, line, handle,
 168                                                    inode, path->p_bh);
 169         } else {
 170                 /* path points to leaf/index in inode body */
 171                 err = ext4_mark_inode_dirty(handle, inode);
 172         }
 173         return err;
 174 }
 175
 176 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
 177                               struct ext4_ext_path *path,
 178                               ext4_lblk_t block)
 179 {
 180         if (path) {
 181                 int depth = path->p_depth;
 182                 struct ext4_extent *ex;
 183
 184                 /*
 185                  * Try to predict block placement assuming that we are
 186                  * filling in a file which will eventually be
 187                  * non-sparse --- i.e., in the case of libbfd writing
 188                  * an ELF object sections out-of-order but in a way
 189                  * the eventually results in a contiguous object or
 190                  * executable file, or some database extending a table
 191                  * space file.  However, this is actually somewhat
 192                  * non-ideal if we are writing a sparse file such as
 193                  * qemu or KVM writing a raw image file that is going
 194                  * to stay fairly sparse, since it will end up
 195                  * fragmenting the file system's free space.  Maybe we
 196                  * should have some hueristics or some way to allow
 197                  * userspace to pass a hint to file system,
 198                  * especially if the latter case turns out to be
 199                  * common.
 200                  */
 201                 ex = path[depth].p_ext;
 202                 if (ex) {
 203                         ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
 204                         ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
 205
 206                         if (block > ext_block)
 207                                 return ext_pblk + (block - ext_block);
 208                         else
 209                                 return ext_pblk - (ext_block - block);
 210                 }
 211
 212                 /* it looks like index is empty;
 213                  * try to find starting block from index itself */
 214                 if (path[depth].p_bh)
 215                         return path[depth].p_bh->b_blocknr;
 216         }
 217
 218         /* OK. use inode's group */
 219         return ext4_inode_to_goal_block(inode);
 220 }
 221
 222 /*
 223  * Allocation for a meta data block
 224  */
 225 static ext4_fsblk_t
 226 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
 227                         struct ext4_ext_path *path,
 228                         struct ext4_extent *ex, int *err, unsigned int flags)
 229 {
 230         ext4_fsblk_t goal, newblock;
 231
 232         goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
 233         newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
 234                                         NULL, err);
 235         return newblock;
 236 }
 237
 238 static inline int ext4_ext_space_block(struct inode *inode, int check)
 239 {
 240         int size;
 241
 242         size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 243                         / sizeof(struct ext4_extent);
 244 #ifdef AGGRESSIVE_TEST
 245         if (!check && size > 6)
 246                 size = 6;
 247 #endif
 248         return size;
 249 }
 250
 251 static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
 252 {
 253         int size;
 254
 255         size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 256                         / sizeof(struct ext4_extent_idx);
 257 #ifdef AGGRESSIVE_TEST
 258         if (!check && size > 5)
 259                 size = 5;
 260 #endif
 261         return size;
 262 }
 263
 264 static inline int ext4_ext_space_root(struct inode *inode, int check)
 265 {
 266         int size;
 267
 268         size = sizeof(EXT4_I(inode)->i_data);
 269         size -= sizeof(struct ext4_extent_header);
 270         size /= sizeof(struct ext4_extent);
 271 #ifdef AGGRESSIVE_TEST
 272         if (!check && size > 3)
 273                 size = 3;
 274 #endif
 275         return size;
 276 }
 277
 278 static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
 279 {
 280         int size;
 281
 282         size = sizeof(EXT4_I(inode)->i_data);
 283         size -= sizeof(struct ext4_extent_header);
 284         size /= sizeof(struct ext4_extent_idx);
 285 #ifdef AGGRESSIVE_TEST
 286         if (!check && size > 4)
 287                 size = 4;
 288 #endif
 289         return size;
 290 }
 291
 292 /*
 293  * Calculate the number of metadata blocks needed
 294  * to allocate @blocks
 295  * Worse case is one block per extent
 296  */
 297 int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
 298 {
 299         struct ext4_inode_info *ei = EXT4_I(inode);
 300         int idxs;
 301
 302         idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 303                 / sizeof(struct ext4_extent_idx));
 304
 305         /*
 306          * If the new delayed allocation block is contiguous with the
 307          * previous da block, it can share index blocks with the
 308          * previous block, so we only need to allocate a new index
 309          * block every idxs leaf blocks.  At ldxs**2 blocks, we need
 310          * an additional index block, and at ldxs**3 blocks, yet
 311          * another index blocks.
 312          */
 313         if (ei->i_da_metadata_calc_len &&
 314             ei->i_da_metadata_calc_last_lblock+1 == lblock) {
 315                 int num = 0;
 316
 317                 if ((ei->i_da_metadata_calc_len % idxs) == 0)
 318                         num++;
 319                 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
 320                         num++;
 321                 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
 322                         num++;
 323                         ei->i_da_metadata_calc_len = 0;
 324                 } else
 325                         ei->i_da_metadata_calc_len++;
 326                 ei->i_da_metadata_calc_last_lblock++;
 327                 return num;
 328         }
 329
 330         /*
 331          * In the worst case we need a new set of index blocks at
 332          * every level of the inode's extent tree.
 333          */
 334         ei->i_da_metadata_calc_len = 1;
 335         ei->i_da_metadata_calc_last_lblock = lblock;
 336         return ext_depth(inode) + 1;
 337 }
 338
 339 static int
 340 ext4_ext_max_entries(struct inode *inode, int depth)
 341 {
 342         int max;
 343
 344         if (depth == ext_depth(inode)) {
 345                 if (depth == 0)
 346                         max = ext4_ext_space_root(inode, 1);
 347                 else
 348                         max = ext4_ext_space_root_idx(inode, 1);
 349         } else {
 350                 if (depth == 0)
 351                         max = ext4_ext_space_block(inode, 1);
 352                 else
 353                         max = ext4_ext_space_block_idx(inode, 1);
 354         }
 355
 356         return max;
 357 }
 358
 359 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
 360 {
 361         ext4_fsblk_t block = ext4_ext_pblock(ext);
 362         int len = ext4_ext_get_actual_len(ext);
 363         ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
 364         ext4_lblk_t last = lblock + len - 1;
 365
 366         if (lblock > last)
 367                 return 0;
 368         return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
 369 }
 370
 371 static int ext4_valid_extent_idx(struct inode *inode,
 372                                 struct ext4_extent_idx *ext_idx)
 373 {
 374         ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
 375
 376         return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
 377 }
 378
 379 static int ext4_valid_extent_entries(struct inode *inode,
 380                                 struct ext4_extent_header *eh,
 381                                 int depth)
 382 {
 383         unsigned short entries;
 384         if (eh->eh_entries == 0)
 385                 return 1;
 386
 387         entries = le16_to_cpu(eh->eh_entries);
 388
 389         if (depth == 0) {
 390                 /* leaf entries */
 391                 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
 392                 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 393                 ext4_fsblk_t pblock = 0;
 394                 ext4_lblk_t lblock = 0;
 395                 ext4_lblk_t prev = 0;
 396                 int len = 0;
 397                 while (entries) {
 398                         if (!ext4_valid_extent(inode, ext))
 399                                 return 0;
 400
 401                         /* Check for overlapping extents */
 402                         lblock = le32_to_cpu(ext->ee_block);
 403                         len = ext4_ext_get_actual_len(ext);
 404                         if ((lblock <= prev) && prev) {
 405                                 pblock = ext4_ext_pblock(ext);
 406                                 es->s_last_error_block = cpu_to_le64(pblock);
 407                                 return 0;
 408                         }
 409                         ext++;
 410                         entries--;
 411                         prev = lblock + len - 1;
 412                 }
 413         } else {
 414                 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
 415                 while (entries) {
 416                         if (!ext4_valid_extent_idx(inode, ext_idx))
 417                                 return 0;
 418                         ext_idx++;
 419                         entries--;
 420                 }
 421         }
 422         return 1;
 423 }
 424
 425 static int __ext4_ext_check(const char *function, unsigned int line,
 426                             struct inode *inode, struct ext4_extent_header *eh,
 427                             int depth, ext4_fsblk_t pblk)
 428 {
 429         const char *error_msg;
 430         int max = 0;
 431
 432         if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
 433                 error_msg = "invalid magic";
 434                 goto corrupted;
 435         }
 436         if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
 437                 error_msg = "unexpected eh_depth";
 438                 goto corrupted;
 439         }
 440         if (unlikely(eh->eh_max == 0)) {
 441                 error_msg = "invalid eh_max";
 442                 goto corrupted;
 443         }
 444         max = ext4_ext_max_entries(inode, depth);
 445         if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
 446                 error_msg = "too large eh_max";
 447                 goto corrupted;
 448         }
 449         if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
 450                 error_msg = "invalid eh_entries";
 451                 goto corrupted;
 452         }
 453         if (!ext4_valid_extent_entries(inode, eh, depth)) {
 454                 error_msg = "invalid extent entries";
 455                 goto corrupted;
 456         }
 457         /* Verify checksum on non-root extent tree nodes */
 458         if (ext_depth(inode) != depth &&
 459             !ext4_extent_block_csum_verify(inode, eh)) {
 460                 error_msg = "extent tree corrupted";
 461                 goto corrupted;
 462         }
 463         return 0;
 464
 465 corrupted:
 466         ext4_error_inode(inode, function, line, 0,
 467                          "pblk %llu bad header/extent: %s - magic %x, "
 468                          "entries %u, max %u(%u), depth %u(%u)",
 469                          (unsigned long long) pblk, error_msg,
 470                          le16_to_cpu(eh->eh_magic),
 471                          le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
 472                          max, le16_to_cpu(eh->eh_depth), depth);
 473         return -EIO;
 474 }
 475
 476 #define ext4_ext_check(inode, eh, depth, pblk)                  \
 477         __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
 478
 479 int ext4_ext_check_inode(struct inode *inode)
 480 {
 481         return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
 482 }
 483
 484 static struct buffer_head *
 485 __read_extent_tree_block(const char *function, unsigned int line,
 486                          struct inode *inode, ext4_fsblk_t pblk, int depth,
 487                          int flags)
 488 {
 489         struct buffer_head              *bh;
 490         int                             err;
 491
 492         bh = sb_getblk(inode->i_sb, pblk);
 493         if (unlikely(!bh))
 494                 return ERR_PTR(-ENOMEM);
 495
 496         if (!bh_uptodate_or_lock(bh)) {
 497                 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
 498                 err = bh_submit_read(bh);
 499                 if (err < 0)
 500                         goto errout;
 501         }
 502         if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
 503                 return bh;
 504         err = __ext4_ext_check(function, line, inode,
 505                                ext_block_hdr(bh), depth, pblk);
 506         if (err)
 507                 goto errout;
 508         set_buffer_verified(bh);
 509         /*
 510          * If this is a leaf block, cache all of its entries
 511          */
 512         if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
 513                 struct ext4_extent_header *eh = ext_block_hdr(bh);
 514                 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
 515                 ext4_lblk_t prev = 0;
 516                 int i;
 517
 518                 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
 519                         unsigned int status = EXTENT_STATUS_WRITTEN;
 520                         ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
 521                         int len = ext4_ext_get_actual_len(ex);
 522
 523                         if (prev && (prev != lblk))
 524                                 ext4_es_cache_extent(inode, prev,
 525                                                      lblk - prev, ~0,
 526                                                      EXTENT_STATUS_HOLE);
 527
 528                         if (ext4_ext_is_uninitialized(ex))
 529                                 status = EXTENT_STATUS_UNWRITTEN;
 530                         ext4_es_cache_extent(inode, lblk, len,
 531                                              ext4_ext_pblock(ex), status);
 532                         prev = lblk + len;
 533                 }
 534         }
 535         return bh;
 536 errout:
 537         put_bh(bh);
 538         return ERR_PTR(err);
 539
 540 }
 541
 542 #define read_extent_tree_block(inode, pblk, depth, flags)               \
 543         __read_extent_tree_block(__func__, __LINE__, (inode), (pblk),   \
 544                                  (depth), (flags))
 545
 546 /*
 547  * This function is called to cache a file's extent information in the
 548  * extent status tree
 549  */
 550 int ext4_ext_precache(struct inode *inode)
 551 {
 552         struct ext4_inode_info *ei = EXT4_I(inode);
 553         struct ext4_ext_path *path = NULL;
 554         struct buffer_head *bh;
 555         int i = 0, depth, ret = 0;
 556
 557         if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
 558                 return 0;       /* not an extent-mapped inode */
 559
 560         down_read(&ei->i_data_sem);
 561         depth = ext_depth(inode);
 562
 563         path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
 564                        GFP_NOFS);
 565         if (path == NULL) {
 566                 up_read(&ei->i_data_sem);
 567                 return -ENOMEM;
 568         }
 569
 570         /* Don't cache anything if there are no external extent blocks */
 571         if (depth == 0)
 572                 goto out;
 573         path[0].p_hdr = ext_inode_hdr(inode);
 574         ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
 575         if (ret)
 576                 goto out;
 577         path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
 578         while (i >= 0) {
 579                 /*
 580                  * If this is a leaf block or we've reached the end of
 581                  * the index block, go up
 582                  */
 583                 if ((i == depth) ||
 584                     path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
 585                         brelse(path[i].p_bh);
 586                         path[i].p_bh = NULL;
 587                         i--;
 588                         continue;
 589                 }
 590                 bh = read_extent_tree_block(inode,
 591                                             ext4_idx_pblock(path[i].p_idx++),
 592                                             depth - i - 1,
 593                                             EXT4_EX_FORCE_CACHE);
 594                 if (IS_ERR(bh)) {
 595                         ret = PTR_ERR(bh);
 596                         break;
 597                 }
 598                 i++;
 599                 path[i].p_bh = bh;
 600                 path[i].p_hdr = ext_block_hdr(bh);
 601                 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
 602         }
 603         ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
 604 out:
 605         up_read(&ei->i_data_sem);
 606         ext4_ext_drop_refs(path);
 607         kfree(path);
 608         return ret;
 609 }
 610
 611 #ifdef EXT_DEBUG
 612 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 613 {
 614         int k, l = path->p_depth;
 615
 616         ext_debug("path:");
 617         for (k = 0; k <= l; k++, path++) {
 618                 if (path->p_idx) {
 619                   ext_debug("  %d->%llu", le32_to_cpu(path->p_idx->ei_block),
 620                             ext4_idx_pblock(path->p_idx));
 621                 } else if (path->p_ext) {
 622                         ext_debug("  %d:[%d]%d:%llu ",
 623                                   le32_to_cpu(path->p_ext->ee_block),
 624                                   ext4_ext_is_uninitialized(path->p_ext),
 625                                   ext4_ext_get_actual_len(path->p_ext),
 626                                   ext4_ext_pblock(path->p_ext));
 627                 } else
 628                         ext_debug("  []");
 629         }
 630         ext_debug("\n");
 631 }
 632
 633 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
 634 {
 635         int depth = ext_depth(inode);
 636         struct ext4_extent_header *eh;
 637         struct ext4_extent *ex;
 638         int i;
 639
 640         if (!path)
 641                 return;
 642
 643         eh = path[depth].p_hdr;
 644         ex = EXT_FIRST_EXTENT(eh);
 645
 646         ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
 647
 648         for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
 649                 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
 650                           ext4_ext_is_uninitialized(ex),
 651                           ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
 652         }
 653         ext_debug("\n");
 654 }
 655
 656 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
 657                         ext4_fsblk_t newblock, int level)
 658 {
 659         int depth = ext_depth(inode);
 660         struct ext4_extent *ex;
 661
 662         if (depth != level) {
 663                 struct ext4_extent_idx *idx;
 664                 idx = path[level].p_idx;
 665                 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
 666                         ext_debug("%d: move %d:%llu in new index %llu\n", level,
 667                                         le32_to_cpu(idx->ei_block),
 668                                         ext4_idx_pblock(idx),
 669                                         newblock);
 670                         idx++;
 671                 }
 672
 673                 return;
 674         }
 675
 676         ex = path[depth].p_ext;
 677         while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
 678                 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
 679                                 le32_to_cpu(ex->ee_block),
 680                                 ext4_ext_pblock(ex),
 681                                 ext4_ext_is_uninitialized(ex),
 682                                 ext4_ext_get_actual_len(ex),
 683                                 newblock);
 684                 ex++;
 685         }
 686 }
 687
 688 #else
 689 #define ext4_ext_show_path(inode, path)
 690 #define ext4_ext_show_leaf(inode, path)
 691 #define ext4_ext_show_move(inode, path, newblock, level)
 692 #endif
 693
 694 void ext4_ext_drop_refs(struct ext4_ext_path *path)
 695 {
 696         int depth = path->p_depth;
 697         int i;
 698
 699         for (i = 0; i <= depth; i++, path++)
 700                 if (path->p_bh) {
 701                         brelse(path->p_bh);
 702                         path->p_bh = NULL;
 703                 }
 704 }
 705
 706 /*
 707  * ext4_ext_binsearch_idx:
 708  * binary search for the closest index of the given block
 709  * the header must be checked before calling this
 710  */
 711 static void
 712 ext4_ext_binsearch_idx(struct inode *inode,
 713                         struct ext4_ext_path *path, ext4_lblk_t block)
 714 {
 715         struct ext4_extent_header *eh = path->p_hdr;
 716         struct ext4_extent_idx *r, *l, *m;
 717
 718
 719         ext_debug("binsearch for %u(idx):  ", block);
 720
 721         l = EXT_FIRST_INDEX(eh) + 1;
 722         r = EXT_LAST_INDEX(eh);
 723         while (l <= r) {
 724                 m = l + (r - l) / 2;
 725                 if (block < le32_to_cpu(m->ei_block))
 726                         r = m - 1;
 727                 else
 728                         l = m + 1;
 729                 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
 730                                 m, le32_to_cpu(m->ei_block),
 731                                 r, le32_to_cpu(r->ei_block));
 732         }
 733
 734         path->p_idx = l - 1;
 735         ext_debug("  -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
 736                   ext4_idx_pblock(path->p_idx));
 737
 738 #ifdef CHECK_BINSEARCH
 739         {
 740                 struct ext4_extent_idx *chix, *ix;
 741                 int k;
 742
 743                 chix = ix = EXT_FIRST_INDEX(eh);
 744                 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
 745                   if (k != 0 &&
 746                       le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
 747                                 printk(KERN_DEBUG "k=%d, ix=0x%p, "
 748                                        "first=0x%p\n", k,
 749                                        ix, EXT_FIRST_INDEX(eh));
 750                                 printk(KERN_DEBUG "%u <= %u\n",
 751                                        le32_to_cpu(ix->ei_block),
 752                                        le32_to_cpu(ix[-1].ei_block));
 753                         }
 754                         BUG_ON(k && le32_to_cpu(ix->ei_block)
 755                                            <= le32_to_cpu(ix[-1].ei_block));
 756                         if (block < le32_to_cpu(ix->ei_block))
 757                                 break;
 758                         chix = ix;
 759                 }
 760                 BUG_ON(chix != path->p_idx);
 761         }
 762 #endif
 763
 764 }
 765
 766 /*
 767  * ext4_ext_binsearch:
 768  * binary search for closest extent of the given block
 769  * the header must be checked before calling this
 770  */
 771 static void
 772 ext4_ext_binsearch(struct inode *inode,
 773                 struct ext4_ext_path *path, ext4_lblk_t block)
 774 {
 775         struct ext4_extent_header *eh = path->p_hdr;
 776         struct ext4_extent *r, *l, *m;
 777
 778         if (eh->eh_entries == 0) {
 779                 /*
 780                  * this leaf is empty:
 781                  * we get such a leaf in split/add case
 782                  */
 783                 return;
 784         }
 785
 786         ext_debug("binsearch for %u:  ", block);
 787
 788         l = EXT_FIRST_EXTENT(eh) + 1;
 789         r = EXT_LAST_EXTENT(eh);
 790
 791         while (l <= r) {
 792                 m = l + (r - l) / 2;
 793                 if (block < le32_to_cpu(m->ee_block))
 794                         r = m - 1;
 795                 else
 796                         l = m + 1;
 797                 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
 798                                 m, le32_to_cpu(m->ee_block),
 799                                 r, le32_to_cpu(r->ee_block));
 800         }
 801
 802         path->p_ext = l - 1;
 803         ext_debug("  -> %d:%llu:[%d]%d ",
 804                         le32_to_cpu(path->p_ext->ee_block),
 805                         ext4_ext_pblock(path->p_ext),
 806                         ext4_ext_is_uninitialized(path->p_ext),
 807                         ext4_ext_get_actual_len(path->p_ext));
 808
 809 #ifdef CHECK_BINSEARCH
 810         {
 811                 struct ext4_extent *chex, *ex;
 812                 int k;
 813
 814                 chex = ex = EXT_FIRST_EXTENT(eh);
 815                 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
 816                         BUG_ON(k && le32_to_cpu(ex->ee_block)
 817                                           <= le32_to_cpu(ex[-1].ee_block));
 818                         if (block < le32_to_cpu(ex->ee_block))
 819                                 break;
 820                         chex = ex;
 821                 }
 822                 BUG_ON(chex != path->p_ext);
 823         }
 824 #endif
 825
 826 }
 827
 828 int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
 829 {
 830         struct ext4_extent_header *eh;
 831
 832         eh = ext_inode_hdr(inode);
 833         eh->eh_depth = 0;
 834         eh->eh_entries = 0;
 835         eh->eh_magic = EXT4_EXT_MAGIC;
 836         eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
 837         ext4_mark_inode_dirty(handle, inode);
 838         return 0;
 839 }
 840
 841 struct ext4_ext_path *
 842 ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 843                      struct ext4_ext_path *path, int flags)
 844 {
 845         struct ext4_extent_header *eh;
 846         struct buffer_head *bh;
 847         short int depth, i, ppos = 0, alloc = 0;
 848         int ret;
 849
 850         eh = ext_inode_hdr(inode);
 851         depth = ext_depth(inode);
 852
 853         /* account possible depth increase */
 854         if (!path) {
 855                 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
 856                                 GFP_NOFS);
 857                 if (!path)
 858                         return ERR_PTR(-ENOMEM);
 859                 alloc = 1;
 860         }
 861         path[0].p_hdr = eh;
 862         path[0].p_bh = NULL;
 863
 864         i = depth;
 865         /* walk through the tree */
 866         while (i) {
 867                 ext_debug("depth %d: num %d, max %d\n",
 868                           ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
 869
 870                 ext4_ext_binsearch_idx(inode, path + ppos, block);
 871                 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
 872                 path[ppos].p_depth = i;
 873                 path[ppos].p_ext = NULL;
 874
 875                 bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
 876                                             flags);
 877                 if (IS_ERR(bh)) {
 878                         ret = PTR_ERR(bh);
 879                         goto err;
 880                 }
 881
 882                 eh = ext_block_hdr(bh);
 883                 ppos++;
 884                 if (unlikely(ppos > depth)) {
 885                         put_bh(bh);
 886                         EXT4_ERROR_INODE(inode,
 887                                          "ppos %d > depth %d", ppos, depth);
 888                         ret = -EIO;
 889                         goto err;
 890                 }
 891                 path[ppos].p_bh = bh;
 892                 path[ppos].p_hdr = eh;
 893         }
 894
 895         path[ppos].p_depth = i;
 896         path[ppos].p_ext = NULL;
 897         path[ppos].p_idx = NULL;
 898
 899         /* find extent */
 900         ext4_ext_binsearch(inode, path + ppos, block);
 901         /* if not an empty leaf */
 902         if (path[ppos].p_ext)
 903                 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
 904
 905         ext4_ext_show_path(inode, path);
 906
 907         return path;
 908
 909 err:
 910         ext4_ext_drop_refs(path);
 911         if (alloc)
 912                 kfree(path);
 913         return ERR_PTR(ret);
 914 }
 915
 916 /*
 917  * ext4_ext_insert_index:
 918  * insert new index [@logical;@ptr] into the block at @curp;
 919  * check where to insert: before @curp or after @curp
 920  */
 921 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 922                                  struct ext4_ext_path *curp,
 923                                  int logical, ext4_fsblk_t ptr)
 924 {
 925         struct ext4_extent_idx *ix;
 926         int len, err;
 927
 928         err = ext4_ext_get_access(handle, inode, curp);
 929         if (err)
 930                 return err;
 931
 932         if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
 933                 EXT4_ERROR_INODE(inode,
 934                                  "logical %d == ei_block %d!",
 935                                  logical, le32_to_cpu(curp->p_idx->ei_block));
 936                 return -EIO;
 937         }
 938
 939         if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
 940                              >= le16_to_cpu(curp->p_hdr->eh_max))) {
 941                 EXT4_ERROR_INODE(inode,
 942                                  "eh_entries %d >= eh_max %d!",
 943                                  le16_to_cpu(curp->p_hdr->eh_entries),
 944                                  le16_to_cpu(curp->p_hdr->eh_max));
 945                 return -EIO;
 946         }
 947
 948         if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
 949                 /* insert after */
 950                 ext_debug("insert new index %d after: %llu\n", logical, ptr);
 951                 ix = curp->p_idx + 1;
 952         } else {
 953                 /* insert before */
 954                 ext_debug("insert new index %d before: %llu\n", logical, ptr);
 955                 ix = curp->p_idx;
 956         }
 957
 958         len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
 959         BUG_ON(len < 0);
 960         if (len > 0) {
 961                 ext_debug("insert new index %d: "
 962                                 "move %d indices from 0x%p to 0x%p\n",
 963                                 logical, len, ix, ix + 1);
 964                 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
 965         }
 966
 967         if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
 968                 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
 969                 return -EIO;
 970         }
 971
 972         ix->ei_block = cpu_to_le32(logical);
 973         ext4_idx_store_pblock(ix, ptr);
 974         le16_add_cpu(&curp->p_hdr->eh_entries, 1);
 975
 976         if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
 977                 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
 978                 return -EIO;
 979         }
 980
 981         err = ext4_ext_dirty(handle, inode, curp);
 982         ext4_std_error(inode->i_sb, err);
 983
 984         return err;
 985 }
 986
 987 /*
 988  * ext4_ext_split:
 989  * inserts new subtree into the path, using free index entry
 990  * at depth @at:
 991  * - allocates all needed blocks (new leaf and all intermediate index blocks)
 992  * - makes decision where to split
 993  * - moves remaining extents and index entries (right to the split point)
 994  *   into the newly allocated blocks
 995  * - initializes subtree
 996  */
 997 static int ext4_ext_split(handle_t *handle, struct inode *inode,
 998                           unsigned int flags,
 999                           struct ext4_ext_path *path,
1000                           struct ext4_extent *newext, int at)
1001 {
1002         struct buffer_head *bh = NULL;
1003         int depth = ext_depth(inode);
1004         struct ext4_extent_header *neh;
1005         struct ext4_extent_idx *fidx;
1006         int i = at, k, m, a;
1007         ext4_fsblk_t newblock, oldblock;
1008         __le32 border;
1009         ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1010         int err = 0;
1011
1012         /* make decision: where to split? */
1013         /* FIXME: now decision is simplest: at current extent */
1014
1015         /* if current leaf will be split, then we should use
1016          * border from split point */
1017         if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1018                 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1019                 return -EIO;
1020         }
1021         if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1022                 border = path[depth].p_ext[1].ee_block;
1023                 ext_debug("leaf will be split."
1024                                 " next leaf starts at %d\n",
1025                                   le32_to_cpu(border));
1026         } else {
1027                 border = newext->ee_block;
1028                 ext_debug("leaf will be added."
1029                                 " next leaf starts at %d\n",
1030                                 le32_to_cpu(border));
1031         }
1032
1033         /*
1034          * If error occurs, then we break processing
1035          * and mark filesystem read-only. index won't
1036          * be inserted and tree will be in consistent
1037          * state. Next mount will repair buffers too.
1038          */
1039
1040         /*
1041          * Get array to track all allocated blocks.
1042          * We need this to handle errors and free blocks
1043          * upon them.
1044          */
1045         ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
1046         if (!ablocks)
1047                 return -ENOMEM;
1048
1049         /* allocate all needed blocks */
1050         ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
1051         for (a = 0; a < depth - at; a++) {
1052                 newblock = ext4_ext_new_meta_block(handle, inode, path,
1053                                                    newext, &err, flags);
1054                 if (newblock == 0)
1055                         goto cleanup;
1056                 ablocks[a] = newblock;
1057         }
1058
1059         /* initialize new leaf */
1060         newblock = ablocks[--a];
1061         if (unlikely(newblock == 0)) {
1062                 EXT4_ERROR_INODE(inode, "newblock == 0!");
1063                 err = -EIO;
1064                 goto cleanup;
1065         }
1066         bh = sb_getblk(inode->i_sb, newblock);
1067         if (unlikely(!bh)) {
1068                 err = -ENOMEM;
1069                 goto cleanup;
1070         }
1071         lock_buffer(bh);
1072
1073         err = ext4_journal_get_create_access(handle, bh);
1074         if (err)
1075                 goto cleanup;
1076
1077         neh = ext_block_hdr(bh);
1078         neh->eh_entries = 0;
1079         neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1080         neh->eh_magic = EXT4_EXT_MAGIC;
1081         neh->eh_depth = 0;
1082
1083         /* move remainder of path[depth] to the new leaf */
1084         if (unlikely(path[depth].p_hdr->eh_entries !=
1085                      path[depth].p_hdr->eh_max)) {
1086                 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1087                                  path[depth].p_hdr->eh_entries,
1088                                  path[depth].p_hdr->eh_max);
1089                 err = -EIO;
1090                 goto cleanup;
1091         }
1092         /* start copy from next extent */
1093         m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1094         ext4_ext_show_move(inode, path, newblock, depth);
1095         if (m) {
1096                 struct ext4_extent *ex;
1097                 ex = EXT_FIRST_EXTENT(neh);
1098                 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1099                 le16_add_cpu(&neh->eh_entries, m);
1100         }
1101
1102         ext4_extent_block_csum_set(inode, neh);
1103         set_buffer_uptodate(bh);
1104         unlock_buffer(bh);
1105
1106         err = ext4_handle_dirty_metadata(handle, inode, bh);
1107         if (err)
1108                 goto cleanup;
1109         brelse(bh);
1110         bh = NULL;
1111
1112         /* correct old leaf */
1113         if (m) {
1114                 err = ext4_ext_get_access(handle, inode, path + depth);
1115                 if (err)
1116                         goto cleanup;
1117                 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1118                 err = ext4_ext_dirty(handle, inode, path + depth);
1119                 if (err)
1120                         goto cleanup;
1121
1122         }
1123
1124         /* create intermediate indexes */
1125         k = depth - at - 1;
1126         if (unlikely(k < 0)) {
1127                 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1128                 err = -EIO;
1129                 goto cleanup;
1130         }
1131         if (k)
1132                 ext_debug("create %d intermediate indices\n", k);
1133         /* insert new index into current index block */
1134         /* current depth stored in i var */
1135         i = depth - 1;
1136         while (k--) {
1137                 oldblock = newblock;
1138                 newblock = ablocks[--a];
1139                 bh = sb_getblk(inode->i_sb, newblock);
1140                 if (unlikely(!bh)) {
1141                         err = -ENOMEM;
1142                         goto cleanup;
1143                 }
1144                 lock_buffer(bh);
1145
1146                 err = ext4_journal_get_create_access(handle, bh);
1147                 if (err)
1148                         goto cleanup;
1149
1150                 neh = ext_block_hdr(bh);
1151                 neh->eh_entries = cpu_to_le16(1);
1152                 neh->eh_magic = EXT4_EXT_MAGIC;
1153                 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1154                 neh->eh_depth = cpu_to_le16(depth - i);
1155                 fidx = EXT_FIRST_INDEX(neh);
1156                 fidx->ei_block = border;
1157                 ext4_idx_store_pblock(fidx, oldblock);
1158
1159                 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1160                                 i, newblock, le32_to_cpu(border), oldblock);
1161
1162                 /* move remainder of path[i] to the new index block */
1163                 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1164                                         EXT_LAST_INDEX(path[i].p_hdr))) {
1165                         EXT4_ERROR_INODE(inode,
1166                                          "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1167                                          le32_to_cpu(path[i].p_ext->ee_block));
1168                         err = -EIO;
1169                         goto cleanup;
1170                 }
1171                 /* start copy indexes */
1172                 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1173                 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1174                                 EXT_MAX_INDEX(path[i].p_hdr));
1175                 ext4_ext_show_move(inode, path, newblock, i);
1176                 if (m) {
1177                         memmove(++fidx, path[i].p_idx,
1178                                 sizeof(struct ext4_extent_idx) * m);
1179                         le16_add_cpu(&neh->eh_entries, m);
1180                 }
1181                 ext4_extent_block_csum_set(inode, neh);
1182                 set_buffer_uptodate(bh);
1183                 unlock_buffer(bh);
1184
1185                 err = ext4_handle_dirty_metadata(handle, inode, bh);
1186                 if (err)
1187                         goto cleanup;
1188                 brelse(bh);
1189                 bh = NULL;
1190
1191                 /* correct old index */
1192                 if (m) {
1193                         err = ext4_ext_get_access(handle, inode, path + i);
1194                         if (err)
1195                                 goto cleanup;
1196                         le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1197                         err = ext4_ext_dirty(handle, inode, path + i);
1198                         if (err)
1199                                 goto cleanup;
1200                 }
1201
1202                 i--;
1203         }
1204
1205         /* insert new index */
1206         err = ext4_ext_insert_index(handle, inode, path + at,
1207                                     le32_to_cpu(border), newblock);
1208
1209 cleanup:
1210         if (bh) {
1211                 if (buffer_locked(bh))
1212                         unlock_buffer(bh);
1213                 brelse(bh);
1214         }
1215
1216         if (err) {
1217                 /* free all allocated blocks in error case */
1218                 for (i = 0; i < depth; i++) {
1219                         if (!ablocks[i])
1220                                 continue;
1221                         ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1222                                          EXT4_FREE_BLOCKS_METADATA);
1223                 }
1224         }
1225         kfree(ablocks);
1226
1227         return err;
1228 }
1229
1230 /*
1231  * ext4_ext_grow_indepth:
1232  * implements tree growing procedure:
1233  * - allocates new block
1234  * - moves top-level data (index block or leaf) into the new block
1235  * - initializes new top-level, creating index that points to the
1236  *   just created block
1237  */
1238 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1239                                  unsigned int flags,
1240                                  struct ext4_extent *newext)
1241 {
1242         struct ext4_extent_header *neh;
1243         struct buffer_head *bh;
1244         ext4_fsblk_t newblock;
1245         int err = 0;
1246
1247         newblock = ext4_ext_new_meta_block(handle, inode, NULL,
1248                 newext, &err, flags);
1249         if (newblock == 0)
1250                 return err;
1251
1252         bh = sb_getblk(inode->i_sb, newblock);
1253         if (unlikely(!bh))
1254                 return -ENOMEM;
1255         lock_buffer(bh);
1256
1257         err = ext4_journal_get_create_access(handle, bh);
1258         if (err) {
1259                 unlock_buffer(bh);
1260                 goto out;
1261         }
1262
1263         /* move top-level index/leaf into new block */
1264         memmove(bh->b_data, EXT4_I(inode)->i_data,
1265                 sizeof(EXT4_I(inode)->i_data));
1266
1267         /* set size of new block */
1268         neh = ext_block_hdr(bh);
1269         /* old root could have indexes or leaves
1270          * so calculate e_max right way */
1271         if (ext_depth(inode))
1272                 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1273         else
1274                 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1275         neh->eh_magic = EXT4_EXT_MAGIC;
1276         ext4_extent_block_csum_set(inode, neh);
1277         set_buffer_uptodate(bh);
1278         unlock_buffer(bh);
1279
1280         err = ext4_handle_dirty_metadata(handle, inode, bh);
1281         if (err)
1282                 goto out;
1283
1284         /* Update top-level index: num,max,pointer */
1285         neh = ext_inode_hdr(inode);
1286         neh->eh_entries = cpu_to_le16(1);
1287         ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1288         if (neh->eh_depth == 0) {
1289                 /* Root extent block becomes index block */
1290                 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1291                 EXT_FIRST_INDEX(neh)->ei_block =
1292                         EXT_FIRST_EXTENT(neh)->ee_block;
1293         }
1294         ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1295                   le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1296                   le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1297                   ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1298
1299         le16_add_cpu(&neh->eh_depth, 1);
1300         ext4_mark_inode_dirty(handle, inode);
1301 out:
1302         brelse(bh);
1303
1304         return err;
1305 }
1306
1307 /*
1308  * ext4_ext_create_new_leaf:
1309  * finds empty index and adds new leaf.
1310  * if no free index is found, then it requests in-depth growing.
1311  */
1312 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1313                                     unsigned int mb_flags,
1314                                     unsigned int gb_flags,
1315                                     struct ext4_ext_path *path,
1316                                     struct ext4_extent *newext)
1317 {
1318         struct ext4_ext_path *curp;
1319         int depth, i, err = 0;
1320
1321 repeat:
1322         i = depth = ext_depth(inode);
1323
1324         /* walk up to the tree and look for free index entry */
1325         curp = path + depth;
1326         while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1327                 i--;
1328                 curp--;
1329         }
1330
1331         /* we use already allocated block for index block,
1332          * so subsequent data blocks should be contiguous */
1333         if (EXT_HAS_FREE_INDEX(curp)) {
1334                 /* if we found index with free entry, then use that
1335                  * entry: create all needed subtree and add new leaf */
1336                 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1337                 if (err)
1338                         goto out;
1339
1340                 /* refill path */
1341                 ext4_ext_drop_refs(path);
1342                 path = ext4_ext_find_extent(inode,
1343                                     (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1344                                     path, gb_flags);
1345                 if (IS_ERR(path))
1346                         err = PTR_ERR(path);
1347         } else {
1348                 /* tree is full, time to grow in depth */
1349                 err = ext4_ext_grow_indepth(handle, inode, mb_flags, newext);
1350                 if (err)
1351                         goto out;
1352
1353                 /* refill path */
1354                 ext4_ext_drop_refs(path);
1355                 path = ext4_ext_find_extent(inode,
1356                                    (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1357                                     path, gb_flags);
1358                 if (IS_ERR(path)) {
1359                         err = PTR_ERR(path);
1360                         goto out;
1361                 }
1362
1363                 /*
1364                  * only first (depth 0 -> 1) produces free space;
1365                  * in all other cases we have to split the grown tree
1366                  */
1367                 depth = ext_depth(inode);
1368                 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1369                         /* now we need to split */
1370                         goto repeat;
1371                 }
1372         }
1373
1374 out:
1375         return err;
1376 }
1377
1378 /*
1379  * search the closest allocated block to the left for *logical
1380  * and returns it at @logical + it's physical address at @phys
1381  * if *logical is the smallest allocated block, the function
1382  * returns 0 at @phys
1383  * return value contains 0 (success) or error code
1384  */
1385 static int ext4_ext_search_left(struct inode *inode,
1386                                 struct ext4_ext_path *path,
1387                                 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1388 {
1389         struct ext4_extent_idx *ix;
1390         struct ext4_extent *ex;
1391         int depth, ee_len;
1392
1393         if (unlikely(path == NULL)) {
1394                 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1395                 return -EIO;
1396         }
1397         depth = path->p_depth;
1398         *phys = 0;
1399
1400         if (depth == 0 && path->p_ext == NULL)
1401                 return 0;
1402
1403         /* usually extent in the path covers blocks smaller
1404          * then *logical, but it can be that extent is the
1405          * first one in the file */
1406
1407         ex = path[depth].p_ext;
1408         ee_len = ext4_ext_get_actual_len(ex);
1409         if (*logical < le32_to_cpu(ex->ee_block)) {
1410                 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1411                         EXT4_ERROR_INODE(inode,
1412                                          "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1413                                          *logical, le32_to_cpu(ex->ee_block));
1414                         return -EIO;
1415                 }
1416                 while (--depth >= 0) {
1417                         ix = path[depth].p_idx;
1418                         if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1419                                 EXT4_ERROR_INODE(inode,
1420                                   "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1421                                   ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1422                                   EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1423                 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1424                                   depth);
1425                                 return -EIO;
1426                         }
1427                 }
1428                 return 0;
1429         }
1430
1431         if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1432                 EXT4_ERROR_INODE(inode,
1433                                  "logical %d < ee_block %d + ee_len %d!",
1434                                  *logical, le32_to_cpu(ex->ee_block), ee_len);
1435                 return -EIO;
1436         }
1437
1438         *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1439         *phys = ext4_ext_pblock(ex) + ee_len - 1;
1440         return 0;
1441 }
1442
1443 /*
1444  * search the closest allocated block to the right for *logical
1445  * and returns it at @logical + it's physical address at @phys
1446  * if *logical is the largest allocated block, the function
1447  * returns 0 at @phys
1448  * return value contains 0 (success) or error code
1449  */
1450 static int ext4_ext_search_right(struct inode *inode,
1451                                  struct ext4_ext_path *path,
1452                                  ext4_lblk_t *logical, ext4_fsblk_t *phys,
1453                                  struct ext4_extent **ret_ex)
1454 {
1455         struct buffer_head *bh = NULL;
1456         struct ext4_extent_header *eh;
1457         struct ext4_extent_idx *ix;
1458         struct ext4_extent *ex;
1459         ext4_fsblk_t block;
1460         int depth;      /* Note, NOT eh_depth; depth from top of tree */
1461         int ee_len;
1462
1463         if (unlikely(path == NULL)) {
1464                 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1465                 return -EIO;
1466         }
1467         depth = path->p_depth;
1468         *phys = 0;
1469
1470         if (depth == 0 && path->p_ext == NULL)
1471                 return 0;
1472
1473         /* usually extent in the path covers blocks smaller
1474          * then *logical, but it can be that extent is the
1475          * first one in the file */
1476
1477         ex = path[depth].p_ext;
1478         ee_len = ext4_ext_get_actual_len(ex);
1479         if (*logical < le32_to_cpu(ex->ee_block)) {
1480                 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1481                         EXT4_ERROR_INODE(inode,
1482                                          "first_extent(path[%d].p_hdr) != ex",
1483                                          depth);
1484                         return -EIO;
1485                 }
1486                 while (--depth >= 0) {
1487                         ix = path[depth].p_idx;
1488                         if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1489                                 EXT4_ERROR_INODE(inode,
1490                                                  "ix != EXT_FIRST_INDEX *logical %d!",
1491                                                  *logical);
1492                                 return -EIO;
1493                         }
1494                 }
1495                 goto found_extent;
1496         }
1497
1498         if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1499                 EXT4_ERROR_INODE(inode,
1500                                  "logical %d < ee_block %d + ee_len %d!",
1501                                  *logical, le32_to_cpu(ex->ee_block), ee_len);
1502                 return -EIO;
1503         }
1504
1505         if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1506                 /* next allocated block in this leaf */
1507                 ex++;
1508                 goto found_extent;
1509         }
1510
1511         /* go up and search for index to the right */
1512         while (--depth >= 0) {
1513                 ix = path[depth].p_idx;
1514                 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1515                         goto got_index;
1516         }
1517
1518         /* we've gone up to the root and found no index to the right */
1519         return 0;
1520
1521 got_index:
1522         /* we've found index to the right, let's
1523          * follow it and find the closest allocated
1524          * block to the right */
1525         ix++;
1526         block = ext4_idx_pblock(ix);
1527         while (++depth < path->p_depth) {
1528                 /* subtract from p_depth to get proper eh_depth */
1529                 bh = read_extent_tree_block(inode, block,
1530                                             path->p_depth - depth, 0);
1531                 if (IS_ERR(bh))
1532                         return PTR_ERR(bh);
1533                 eh = ext_block_hdr(bh);
1534                 ix = EXT_FIRST_INDEX(eh);
1535                 block = ext4_idx_pblock(ix);
1536                 put_bh(bh);
1537         }
1538
1539         bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
1540         if (IS_ERR(bh))
1541                 return PTR_ERR(bh);
1542         eh = ext_block_hdr(bh);
1543         ex = EXT_FIRST_EXTENT(eh);
1544 found_extent:
1545         *logical = le32_to_cpu(ex->ee_block);
1546         *phys = ext4_ext_pblock(ex);
1547         *ret_ex = ex;
1548         if (bh)
1549                 put_bh(bh);
1550         return 0;
1551 }
1552
1553 /*
1554  * ext4_ext_next_allocated_block:
1555  * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1556  * NOTE: it considers block number from index entry as
1557  * allocated block. Thus, index entries have to be consistent
1558  * with leaves.
1559  */
1560 static ext4_lblk_t
1561 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1562 {
1563         int depth;
1564
1565         BUG_ON(path == NULL);
1566         depth = path->p_depth;
1567
1568         if (depth == 0 && path->p_ext == NULL)
1569                 return EXT_MAX_BLOCKS;
1570
1571         while (depth >= 0) {
1572                 if (depth == path->p_depth) {
1573                         /* leaf */
1574                         if (path[depth].p_ext &&
1575                                 path[depth].p_ext !=
1576                                         EXT_LAST_EXTENT(path[depth].p_hdr))
1577                           return le32_to_cpu(path[depth].p_ext[1].ee_block);
1578                 } else {
1579                         /* index */
1580                         if (path[depth].p_idx !=
1581                                         EXT_LAST_INDEX(path[depth].p_hdr))
1582                           return le32_to_cpu(path[depth].p_idx[1].ei_block);
1583                 }
1584                 depth--;
1585         }
1586
1587         return EXT_MAX_BLOCKS;
1588 }
1589
1590 /*
1591  * ext4_ext_next_leaf_block:
1592  * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1593  */
1594 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1595 {
1596         int depth;
1597
1598         BUG_ON(path == NULL);
1599         depth = path->p_depth;
1600
1601         /* zero-tree has no leaf blocks at all */
1602         if (depth == 0)
1603                 return EXT_MAX_BLOCKS;
1604
1605         /* go to index block */
1606         depth--;
1607
1608         while (depth >= 0) {
1609                 if (path[depth].p_idx !=
1610                                 EXT_LAST_INDEX(path[depth].p_hdr))
1611                         return (ext4_lblk_t)
1612                                 le32_to_cpu(path[depth].p_idx[1].ei_block);
1613                 depth--;
1614         }
1615
1616         return EXT_MAX_BLOCKS;
1617 }
1618
1619 /*
1620  * ext4_ext_correct_indexes:
1621  * if leaf gets modified and modified extent is first in the leaf,
1622  * then we have to correct all indexes above.
1623  * TODO: do we need to correct tree in all cases?
1624  */
1625 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1626                                 struct ext4_ext_path *path)
1627 {
1628         struct ext4_extent_header *eh;
1629         int depth = ext_depth(inode);
1630         struct ext4_extent *ex;
1631         __le32 border;
1632         int k, err = 0;
1633
1634         eh = path[depth].p_hdr;
1635         ex = path[depth].p_ext;
1636
1637         if (unlikely(ex == NULL || eh == NULL)) {
1638                 EXT4_ERROR_INODE(inode,
1639                                  "ex %p == NULL or eh %p == NULL", ex, eh);
1640                 return -EIO;
1641         }
1642
1643         if (depth == 0) {
1644                 /* there is no tree at all */
1645                 return 0;
1646         }
1647
1648         if (ex != EXT_FIRST_EXTENT(eh)) {
1649                 /* we correct tree if first leaf got modified only */
1650                 return 0;
1651         }
1652
1653         /*
1654          * TODO: we need correction if border is smaller than current one
1655          */
1656         k = depth - 1;
1657         border = path[depth].p_ext->ee_block;
1658         err = ext4_ext_get_access(handle, inode, path + k);
1659         if (err)
1660                 return err;
1661         path[k].p_idx->ei_block = border;
1662         err = ext4_ext_dirty(handle, inode, path + k);
1663         if (err)
1664                 return err;
1665
1666         while (k--) {
1667                 /* change all left-side indexes */
1668                 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1669                         break;
1670                 err = ext4_ext_get_access(handle, inode, path + k);
1671                 if (err)
1672                         break;
1673                 path[k].p_idx->ei_block = border;
1674                 err = ext4_ext_dirty(handle, inode, path + k);
1675                 if (err)
1676                         break;
1677         }
1678
1679         return err;
1680 }
1681
1682 int
1683 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1684                                 struct ext4_extent *ex2)
1685 {
1686         unsigned short ext1_ee_len, ext2_ee_len;
1687
1688         /*
1689          * Make sure that both extents are initialized. We don't merge
1690          * uninitialized extents so that we can be sure that end_io code has
1691          * the extent that was written properly split out and conversion to
1692          * initialized is trivial.
1693          */
1694         if (ext4_ext_is_uninitialized(ex1) || ext4_ext_is_uninitialized(ex2))
1695                 return 0;
1696
1697         ext1_ee_len = ext4_ext_get_actual_len(ex1);
1698         ext2_ee_len = ext4_ext_get_actual_len(ex2);
1699
1700         if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1701                         le32_to_cpu(ex2->ee_block))
1702                 return 0;
1703
1704         /*
1705          * To allow future support for preallocated extents to be added
1706          * as an RO_COMPAT feature, refuse to merge to extents if
1707          * this can result in the top bit of ee_len being set.
1708          */
1709         if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1710                 return 0;
1711 #ifdef AGGRESSIVE_TEST
1712         if (ext1_ee_len >= 4)
1713                 return 0;
1714 #endif
1715
1716         if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1717                 return 1;
1718         return 0;
1719 }
1720
1721 /*
1722  * This function tries to merge the "ex" extent to the next extent in the tree.
1723  * It always tries to merge towards right. If you want to merge towards
1724  * left, pass "ex - 1" as argument instead of "ex".
1725  * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1726  * 1 if they got merged.
1727  */
1728 static int ext4_ext_try_to_merge_right(struct inode *inode,
1729                                  struct ext4_ext_path *path,
1730                                  struct ext4_extent *ex)
1731 {
1732         struct ext4_extent_header *eh;
1733         unsigned int depth, len;
1734         int merge_done = 0;
1735
1736         depth = ext_depth(inode);
1737         BUG_ON(path[depth].p_hdr == NULL);
1738         eh = path[depth].p_hdr;
1739
1740         while (ex < EXT_LAST_EXTENT(eh)) {
1741                 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1742                         break;
1743                 /* merge with next extent! */
1744                 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1745                                 + ext4_ext_get_actual_len(ex + 1));
1746
1747                 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1748                         len = (EXT_LAST_EXTENT(eh) - ex - 1)
1749                                 * sizeof(struct ext4_extent);
1750                         memmove(ex + 1, ex + 2, len);
1751                 }
1752                 le16_add_cpu(&eh->eh_entries, -1);
1753                 merge_done = 1;
1754                 WARN_ON(eh->eh_entries == 0);
1755                 if (!eh->eh_entries)
1756                         EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1757         }
1758
1759         return merge_done;
1760 }
1761
1762 /*
1763  * This function does a very simple check to see if we can collapse
1764  * an extent tree with a single extent tree leaf block into the inode.
1765  */
1766 static void ext4_ext_try_to_merge_up(handle_t *handle,
1767                                      struct inode *inode,
1768                                      struct ext4_ext_path *path)
1769 {
1770         size_t s;
1771         unsigned max_root = ext4_ext_space_root(inode, 0);
1772         ext4_fsblk_t blk;
1773
1774         if ((path[0].p_depth != 1) ||
1775             (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1776             (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1777                 return;
1778
1779         /*
1780          * We need to modify the block allocation bitmap and the block
1781          * group descriptor to release the extent tree block.  If we
1782          * can't get the journal credits, give up.
1783          */
1784         if (ext4_journal_extend(handle, 2))
1785                 return;
1786
1787         /*
1788          * Copy the extent data up to the inode
1789          */
1790         blk = ext4_idx_pblock(path[0].p_idx);
1791         s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1792                 sizeof(struct ext4_extent_idx);
1793         s += sizeof(struct ext4_extent_header);
1794
1795         memcpy(path[0].p_hdr, path[1].p_hdr, s);
1796         path[0].p_depth = 0;
1797         path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1798                 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1799         path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1800
1801         brelse(path[1].p_bh);
1802         ext4_free_blocks(handle, inode, NULL, blk, 1,
1803                          EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET |
1804                          EXT4_FREE_BLOCKS_RESERVE);
1805 }
1806
1807 /*
1808  * This function tries to merge the @ex extent to neighbours in the tree.
1809  * return 1 if merge left else 0.
1810  */
1811 static void ext4_ext_try_to_merge(handle_t *handle,
1812                                   struct inode *inode,
1813                                   struct ext4_ext_path *path,
1814                                   struct ext4_extent *ex) {
1815         struct ext4_extent_header *eh;
1816         unsigned int depth;
1817         int merge_done = 0;
1818
1819         depth = ext_depth(inode);
1820         BUG_ON(path[depth].p_hdr == NULL);
1821         eh = path[depth].p_hdr;
1822
1823         if (ex > EXT_FIRST_EXTENT(eh))
1824                 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1825
1826         if (!merge_done)
1827                 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1828
1829         ext4_ext_try_to_merge_up(handle, inode, path);
1830 }
1831
1832 /*
1833  * check if a portion of the "newext" extent overlaps with an
1834  * existing extent.
1835  *
1836  * If there is an overlap discovered, it updates the length of the newext
1837  * such that there will be no overlap, and then returns 1.
1838  * If there is no overlap found, it returns 0.
1839  */
1840 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1841                                            struct inode *inode,
1842                                            struct ext4_extent *newext,
1843                                            struct ext4_ext_path *path)
1844 {
1845         ext4_lblk_t b1, b2;
1846         unsigned int depth, len1;
1847         unsigned int ret = 0;
1848
1849         b1 = le32_to_cpu(newext->ee_block);
1850         len1 = ext4_ext_get_actual_len(newext);
1851         depth = ext_depth(inode);
1852         if (!path[depth].p_ext)
1853                 goto out;
1854         b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1855
1856         /*
1857          * get the next allocated block if the extent in the path
1858          * is before the requested block(s)
1859          */
1860         if (b2 < b1) {
1861                 b2 = ext4_ext_next_allocated_block(path);
1862                 if (b2 == EXT_MAX_BLOCKS)
1863                         goto out;
1864                 b2 = EXT4_LBLK_CMASK(sbi, b2);
1865         }
1866
1867         /* check for wrap through zero on extent logical start block*/
1868         if (b1 + len1 < b1) {
1869                 len1 = EXT_MAX_BLOCKS - b1;
1870                 newext->ee_len = cpu_to_le16(len1);
1871                 ret = 1;
1872         }
1873
1874         /* check for overlap */
1875         if (b1 + len1 > b2) {
1876                 newext->ee_len = cpu_to_le16(b2 - b1);
1877                 ret = 1;
1878         }
1879 out:
1880         return ret;
1881 }
1882
1883 /*
1884  * ext4_ext_insert_extent:
1885  * tries to merge requsted extent into the existing extent or
1886  * inserts requested extent as new one into the tree,
1887  * creating new leaf in the no-space case.
1888  */
1889 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1890                                 struct ext4_ext_path *path,
1891                                 struct ext4_extent *newext, int gb_flags)
1892 {
1893         struct ext4_extent_header *eh;
1894         struct ext4_extent *ex, *fex;
1895         struct ext4_extent *nearex; /* nearest extent */
1896         struct ext4_ext_path *npath = NULL;
1897         int depth, len, err;
1898         ext4_lblk_t next;
1899         int mb_flags = 0;
1900
1901         if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1902                 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1903                 return -EIO;
1904         }
1905         depth = ext_depth(inode);
1906         ex = path[depth].p_ext;
1907         eh = path[depth].p_hdr;
1908         if (unlikely(path[depth].p_hdr == NULL)) {
1909                 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1910                 return -EIO;
1911         }
1912
1913         /* try to insert block into found extent and return */
1914         if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1915
1916                 /*
1917                  * Try to see whether we should rather test the extent on
1918                  * right from ex, or from the left of ex. This is because
1919                  * ext4_ext_find_extent() can return either extent on the
1920                  * left, or on the right from the searched position. This
1921                  * will make merging more effective.
1922                  */
1923                 if (ex < EXT_LAST_EXTENT(eh) &&
1924                     (le32_to_cpu(ex->ee_block) +
1925                     ext4_ext_get_actual_len(ex) <
1926                     le32_to_cpu(newext->ee_block))) {
1927                         ex += 1;
1928                         goto prepend;
1929                 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
1930                            (le32_to_cpu(newext->ee_block) +
1931                            ext4_ext_get_actual_len(newext) <
1932                            le32_to_cpu(ex->ee_block)))
1933                         ex -= 1;
1934
1935                 /* Try to append newex to the ex */
1936                 if (ext4_can_extents_be_merged(inode, ex, newext)) {
1937                         ext_debug("append [%d]%d block to %u:[%d]%d"
1938                                   "(from %llu)\n",
1939                                   ext4_ext_is_uninitialized(newext),
1940                                   ext4_ext_get_actual_len(newext),
1941                                   le32_to_cpu(ex->ee_block),
1942                                   ext4_ext_is_uninitialized(ex),
1943                                   ext4_ext_get_actual_len(ex),
1944                                   ext4_ext_pblock(ex));
1945                         err = ext4_ext_get_access(handle, inode,
1946                                                   path + depth);
1947                         if (err)
1948                                 return err;
1949
1950                         ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1951                                         + ext4_ext_get_actual_len(newext));
1952                         eh = path[depth].p_hdr;
1953                         nearex = ex;
1954                         goto merge;
1955                 }
1956
1957 prepend:
1958                 /* Try to prepend newex to the ex */
1959                 if (ext4_can_extents_be_merged(inode, newext, ex)) {
1960                         ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
1961                                   "(from %llu)\n",
1962                                   le32_to_cpu(newext->ee_block),
1963                                   ext4_ext_is_uninitialized(newext),
1964                                   ext4_ext_get_actual_len(newext),
1965                                   le32_to_cpu(ex->ee_block),
1966                                   ext4_ext_is_uninitialized(ex),
1967                                   ext4_ext_get_actual_len(ex),
1968                                   ext4_ext_pblock(ex));
1969                         err = ext4_ext_get_access(handle, inode,
1970                                                   path + depth);
1971                         if (err)
1972                                 return err;
1973
1974                         ex->ee_block = newext->ee_block;
1975                         ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
1976                         ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1977                                         + ext4_ext_get_actual_len(newext));
1978                         eh = path[depth].p_hdr;
1979                         nearex = ex;
1980                         goto merge;
1981                 }
1982         }
1983
1984         depth = ext_depth(inode);
1985         eh = path[depth].p_hdr;
1986         if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1987                 goto has_space;
1988
1989         /* probably next leaf has space for us? */
1990         fex = EXT_LAST_EXTENT(eh);
1991         next = EXT_MAX_BLOCKS;
1992         if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
1993                 next = ext4_ext_next_leaf_block(path);
1994         if (next != EXT_MAX_BLOCKS) {
1995                 ext_debug("next leaf block - %u\n", next);
1996                 BUG_ON(npath != NULL);
1997                 npath = ext4_ext_find_extent(inode, next, NULL, 0);
1998                 if (IS_ERR(npath))
1999                         return PTR_ERR(npath);
2000                 BUG_ON(npath->p_depth != path->p_depth);
2001                 eh = npath[depth].p_hdr;
2002                 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2003                         ext_debug("next leaf isn't full(%d)\n",
2004                                   le16_to_cpu(eh->eh_entries));
2005                         path = npath;
2006                         goto has_space;
2007                 }
2008                 ext_debug("next leaf has no free space(%d,%d)\n",
2009                           le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2010         }
2011
2012         /*
2013          * There is no free space in the found leaf.
2014          * We're gonna add a new leaf in the tree.
2015          */
2016         if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2017                 mb_flags = EXT4_MB_USE_RESERVED;
2018         err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2019                                        path, newext);
2020         if (err)
2021                 goto cleanup;
2022         depth = ext_depth(inode);
2023         eh = path[depth].p_hdr;
2024
2025 has_space:
2026         nearex = path[depth].p_ext;
2027
2028         err = ext4_ext_get_access(handle, inode, path + depth);
2029         if (err)
2030                 goto cleanup;
2031
2032         if (!nearex) {
2033                 /* there is no extent in this leaf, create first one */
2034                 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
2035                                 le32_to_cpu(newext->ee_block),
2036                                 ext4_ext_pblock(newext),
2037                                 ext4_ext_is_uninitialized(newext),
2038                                 ext4_ext_get_actual_len(newext));
2039                 nearex = EXT_FIRST_EXTENT(eh);
2040         } else {
2041                 if (le32_to_cpu(newext->ee_block)
2042                            > le32_to_cpu(nearex->ee_block)) {
2043                         /* Insert after */
2044                         ext_debug("insert %u:%llu:[%d]%d before: "
2045                                         "nearest %p\n",
2046                                         le32_to_cpu(newext->ee_block),
2047                                         ext4_ext_pblock(newext),
2048                                         ext4_ext_is_uninitialized(newext),
2049                                         ext4_ext_get_actual_len(newext),
2050                                         nearex);
2051                         nearex++;
2052                 } else {
2053                         /* Insert before */
2054                         BUG_ON(newext->ee_block == nearex->ee_block);
2055                         ext_debug("insert %u:%llu:[%d]%d after: "
2056                                         "nearest %p\n",
2057                                         le32_to_cpu(newext->ee_block),
2058                                         ext4_ext_pblock(newext),
2059                                         ext4_ext_is_uninitialized(newext),
2060                                         ext4_ext_get_actual_len(newext),
2061                                         nearex);
2062                 }
2063                 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2064                 if (len > 0) {
2065                         ext_debug("insert %u:%llu:[%d]%d: "
2066                                         "move %d extents from 0x%p to 0x%p\n",
2067                                         le32_to_cpu(newext->ee_block),
2068                                         ext4_ext_pblock(newext),
2069                                         ext4_ext_is_uninitialized(newext),
2070                                         ext4_ext_get_actual_len(newext),
2071                                         len, nearex, nearex + 1);
2072                         memmove(nearex + 1, nearex,
2073                                 len * sizeof(struct ext4_extent));
2074                 }
2075         }
2076
2077         le16_add_cpu(&eh->eh_entries, 1);
2078         path[depth].p_ext = nearex;
2079         nearex->ee_block = newext->ee_block;
2080         ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2081         nearex->ee_len = newext->ee_len;
2082
2083 merge:
2084         /* try to merge extents */
2085         if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2086                 ext4_ext_try_to_merge(handle, inode, path, nearex);
2087
2088
2089         /* time to correct all indexes above */
2090         err = ext4_ext_correct_indexes(handle, inode, path);
2091         if (err)
2092                 goto cleanup;
2093
2094         err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2095
2096 cleanup:
2097         if (npath) {
2098                 ext4_ext_drop_refs(npath);
2099                 kfree(npath);
2100         }
2101         return err;
2102 }
2103
2104 static int ext4_fill_fiemap_extents(struct inode *inode,
2105                                     ext4_lblk_t block, ext4_lblk_t num,
2106                                     struct fiemap_extent_info *fieinfo)
2107 {
2108         struct ext4_ext_path *path = NULL;
2109         struct ext4_extent *ex;
2110         struct extent_status es;
2111         ext4_lblk_t next, next_del, start = 0, end = 0;
2112         ext4_lblk_t last = block + num;
2113         int exists, depth = 0, err = 0;
2114         unsigned int flags = 0;
2115         unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2116
2117         while (block < last && block != EXT_MAX_BLOCKS) {
2118                 num = last - block;
2119                 /* find extent for this block */
2120                 down_read(&EXT4_I(inode)->i_data_sem);
2121
2122                 if (path && ext_depth(inode) != depth) {
2123                         /* depth was changed. we have to realloc path */
2124                         kfree(path);
2125                         path = NULL;
2126                 }
2127
2128                 path = ext4_ext_find_extent(inode, block, path, 0);
2129                 if (IS_ERR(path)) {
2130                         up_read(&EXT4_I(inode)->i_data_sem);
2131                         err = PTR_ERR(path);
2132                         path = NULL;
2133                         break;
2134                 }
2135
2136                 depth = ext_depth(inode);
2137                 if (unlikely(path[depth].p_hdr == NULL)) {
2138                         up_read(&EXT4_I(inode)->i_data_sem);
2139                         EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2140                         err = -EIO;
2141                         break;
2142                 }
2143                 ex = path[depth].p_ext;
2144                 next = ext4_ext_next_allocated_block(path);
2145                 ext4_ext_drop_refs(path);
2146
2147                 flags = 0;
2148                 exists = 0;
2149                 if (!ex) {
2150                         /* there is no extent yet, so try to allocate
2151                          * all requested space */
2152                         start = block;
2153                         end = block + num;
2154                 } else if (le32_to_cpu(ex->ee_block) > block) {
2155                         /* need to allocate space before found extent */
2156                         start = block;
2157                         end = le32_to_cpu(ex->ee_block);
2158                         if (block + num < end)
2159                                 end = block + num;
2160                 } else if (block >= le32_to_cpu(ex->ee_block)
2161                                         + ext4_ext_get_actual_len(ex)) {
2162                         /* need to allocate space after found extent */
2163                         start = block;
2164                         end = block + num;
2165                         if (end >= next)
2166                                 end = next;
2167                 } else if (block >= le32_to_cpu(ex->ee_block)) {
2168                         /*
2169                          * some part of requested space is covered
2170                          * by found extent
2171                          */
2172                         start = block;
2173                         end = le32_to_cpu(ex->ee_block)
2174                                 + ext4_ext_get_actual_len(ex);
2175                         if (block + num < end)
2176                                 end = block + num;
2177                         exists = 1;
2178                 } else {
2179                         BUG();
2180                 }
2181                 BUG_ON(end <= start);
2182
2183                 if (!exists) {
2184                         es.es_lblk = start;
2185                         es.es_len = end - start;
2186                         es.es_pblk = 0;
2187                 } else {
2188                         es.es_lblk = le32_to_cpu(ex->ee_block);
2189                         es.es_len = ext4_ext_get_actual_len(ex);
2190                         es.es_pblk = ext4_ext_pblock(ex);
2191                         if (ext4_ext_is_uninitialized(ex))
2192                                 flags |= FIEMAP_EXTENT_UNWRITTEN;
2193                 }
2194
2195                 /*
2196                  * Find delayed extent and update es accordingly. We call
2197                  * it even in !exists case to find out whether es is the
2198                  * last existing extent or not.
2199                  */
2200                 next_del = ext4_find_delayed_extent(inode, &es);
2201                 if (!exists && next_del) {
2202                         exists = 1;
2203                         flags |= (FIEMAP_EXTENT_DELALLOC |
2204                                   FIEMAP_EXTENT_UNKNOWN);
2205                 }
2206                 up_read(&EXT4_I(inode)->i_data_sem);
2207
2208                 if (unlikely(es.es_len == 0)) {
2209                         EXT4_ERROR_INODE(inode, "es.es_len == 0");
2210                         err = -EIO;
2211                         break;
2212                 }
2213
2214                 /*
2215                  * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2216                  * we need to check next == EXT_MAX_BLOCKS because it is
2217                  * possible that an extent is with unwritten and delayed
2218                  * status due to when an extent is delayed allocated and
2219                  * is allocated by fallocate status tree will track both of
2220                  * them in a extent.
2221                  *
2222                  * So we could return a unwritten and delayed extent, and
2223                  * its block is equal to 'next'.
2224                  */
2225                 if (next == next_del && next == EXT_MAX_BLOCKS) {
2226                         flags |= FIEMAP_EXTENT_LAST;
2227                         if (unlikely(next_del != EXT_MAX_BLOCKS ||
2228                                      next != EXT_MAX_BLOCKS)) {
2229                                 EXT4_ERROR_INODE(inode,
2230                                                  "next extent == %u, next "
2231                                                  "delalloc extent = %u",
2232                                                  next, next_del);
2233                                 err = -EIO;
2234                                 break;
2235                         }
2236                 }
2237
2238                 if (exists) {
2239                         err = fiemap_fill_next_extent(fieinfo,
2240                                 (__u64)es.es_lblk << blksize_bits,
2241                                 (__u64)es.es_pblk << blksize_bits,
2242                                 (__u64)es.es_len << blksize_bits,
2243                                 flags);
2244                         if (err < 0)
2245                                 break;
2246                         if (err == 1) {
2247                                 err = 0;
2248                                 break;
2249                         }
2250                 }
2251
2252                 block = es.es_lblk + es.es_len;
2253         }
2254
2255         if (path) {
2256                 ext4_ext_drop_refs(path);
2257                 kfree(path);
2258         }
2259
2260         return err;
2261 }
2262
2263 /*
2264  * ext4_ext_put_gap_in_cache:
2265  * calculate boundaries of the gap that the requested block fits into
2266  * and cache this gap
2267  */
2268 static void
2269 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
2270                                 ext4_lblk_t block)
2271 {
2272         int depth = ext_depth(inode);
2273         unsigned long len = 0;
2274         ext4_lblk_t lblock = 0;
2275         struct ext4_extent *ex;
2276
2277         ex = path[depth].p_ext;
2278         if (ex == NULL) {
2279                 /*
2280                  * there is no extent yet, so gap is [0;-] and we
2281                  * don't cache it
2282                  */
2283                 ext_debug("cache gap(whole file):");
2284         } else if (block < le32_to_cpu(ex->ee_block)) {
2285                 lblock = block;
2286                 len = le32_to_cpu(ex->ee_block) - block;
2287                 ext_debug("cache gap(before): %u [%u:%u]",
2288                                 block,
2289                                 le32_to_cpu(ex->ee_block),
2290                                  ext4_ext_get_actual_len(ex));
2291                 if (!ext4_find_delalloc_range(inode, lblock, lblock + len - 1))
2292                         ext4_es_insert_extent(inode, lblock, len, ~0,
2293                                               EXTENT_STATUS_HOLE);
2294         } else if (block >= le32_to_cpu(ex->ee_block)
2295                         + ext4_ext_get_actual_len(ex)) {
2296                 ext4_lblk_t next;
2297                 lblock = le32_to_cpu(ex->ee_block)
2298                         + ext4_ext_get_actual_len(ex);
2299
2300                 next = ext4_ext_next_allocated_block(path);
2301                 ext_debug("cache gap(after): [%u:%u] %u",
2302                                 le32_to_cpu(ex->ee_block),
2303                                 ext4_ext_get_actual_len(ex),
2304                                 block);
2305                 BUG_ON(next == lblock);
2306                 len = next - lblock;
2307                 if (!ext4_find_delalloc_range(inode, lblock, lblock + len - 1))
2308                         ext4_es_insert_extent(inode, lblock, len, ~0,
2309                                               EXTENT_STATUS_HOLE);
2310         } else {
2311                 BUG();
2312         }
2313
2314         ext_debug(" -> %u:%lu\n", lblock, len);
2315 }
2316
2317 /*
2318  * ext4_ext_rm_idx:
2319  * removes index from the index block.
2320  */
2321 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2322                         struct ext4_ext_path *path, int depth)
2323 {
2324         int err;
2325         ext4_fsblk_t leaf;
2326
2327         /* free index block */
2328         depth--;
2329         path = path + depth;
2330         leaf = ext4_idx_pblock(path->p_idx);
2331         if (unlikely(path->p_hdr->eh_entries == 0)) {
2332                 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2333                 return -EIO;
2334         }
2335         err = ext4_ext_get_access(handle, inode, path);
2336         if (err)
2337                 return err;
2338
2339         if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2340                 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2341                 len *= sizeof(struct ext4_extent_idx);
2342                 memmove(path->p_idx, path->p_idx + 1, len);
2343         }
2344
2345         le16_add_cpu(&path->p_hdr->eh_entries, -1);
2346         err = ext4_ext_dirty(handle, inode, path);
2347         if (err)
2348                 return err;
2349         ext_debug("index is empty, remove it, free block %llu\n", leaf);
2350         trace_ext4_ext_rm_idx(inode, leaf);
2351
2352         ext4_free_blocks(handle, inode, NULL, leaf, 1,
2353                          EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2354
2355         while (--depth >= 0) {
2356                 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2357                         break;
2358                 path--;
2359                 err = ext4_ext_get_access(handle, inode, path);
2360                 if (err)
2361                         break;
2362                 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2363                 err = ext4_ext_dirty(handle, inode, path);
2364                 if (err)
2365                         break;
2366         }
2367         return err;
2368 }
2369
2370 /*
2371  * ext4_ext_calc_credits_for_single_extent:
2372  * This routine returns max. credits that needed to insert an extent
2373  * to the extent tree.
2374  * When pass the actual path, the caller should calculate credits
2375  * under i_data_sem.
2376  */
2377 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2378                                                 struct ext4_ext_path *path)
2379 {
2380         if (path) {
2381                 int depth = ext_depth(inode);
2382                 int ret = 0;
2383
2384                 /* probably there is space in leaf? */
2385                 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2386                                 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2387
2388                         /*
2389                          *  There are some space in the leaf tree, no
2390                          *  need to account for leaf block credit
2391                          *
2392                          *  bitmaps and block group descriptor blocks
2393                          *  and other metadata blocks still need to be
2394                          *  accounted.
2395                          */
2396                         /* 1 bitmap, 1 block group descriptor */
2397                         ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2398                         return ret;
2399                 }
2400         }
2401
2402         return ext4_chunk_trans_blocks(inode, nrblocks);
2403 }
2404
2405 /*
2406  * How many index/leaf blocks need to change/allocate to add @extents extents?
2407  *
2408  * If we add a single extent, then in the worse case, each tree level
2409  * index/leaf need to be changed in case of the tree split.
2410  *
2411  * If more extents are inserted, they could cause the whole tree split more
2412  * than once, but this is really rare.
2413  */
2414 int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2415 {
2416         int index;
2417         int depth;
2418
2419         /* If we are converting the inline data, only one is needed here. */
2420         if (ext4_has_inline_data(inode))
2421                 return 1;
2422
2423         depth = ext_depth(inode);
2424
2425         if (extents <= 1)
2426                 index = depth * 2;
2427         else
2428                 index = depth * 3;
2429
2430         return index;
2431 }
2432
2433 static inline int get_default_free_blocks_flags(struct inode *inode)
2434 {
2435         if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2436                 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2437         else if (ext4_should_journal_data(inode))
2438                 return EXT4_FREE_BLOCKS_FORGET;
2439         return 0;
2440 }
2441
2442 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2443                               struct ext4_extent *ex,
2444                               long long *partial_cluster,
2445                               ext4_lblk_t from, ext4_lblk_t to)
2446 {
2447         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2448         unsigned short ee_len =  ext4_ext_get_actual_len(ex);
2449         ext4_fsblk_t pblk;
2450         int flags = get_default_free_blocks_flags(inode);
2451
2452         /*
2453          * For bigalloc file systems, we never free a partial cluster
2454          * at the beginning of the extent.  Instead, we make a note
2455          * that we tried freeing the cluster, and check to see if we
2456          * need to free it on a subsequent call to ext4_remove_blocks,
2457          * or at the end of the ext4_truncate() operation.
2458          */
2459         flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2460
2461         trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2462         /*
2463          * If we have a partial cluster, and it's different from the
2464          * cluster of the last block, we need to explicitly free the
2465          * partial cluster here.
2466          */
2467         pblk = ext4_ext_pblock(ex) + ee_len - 1;
2468         if ((*partial_cluster > 0) &&
2469             (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
2470                 ext4_free_blocks(handle, inode, NULL,
2471                                  EXT4_C2B(sbi, *partial_cluster),
2472                                  sbi->s_cluster_ratio, flags);
2473                 *partial_cluster = 0;
2474         }
2475
2476 #ifdef EXTENTS_STATS
2477         {
2478                 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2479                 spin_lock(&sbi->s_ext_stats_lock);
2480                 sbi->s_ext_blocks += ee_len;
2481                 sbi->s_ext_extents++;
2482                 if (ee_len < sbi->s_ext_min)
2483                         sbi->s_ext_min = ee_len;
2484                 if (ee_len > sbi->s_ext_max)
2485                         sbi->s_ext_max = ee_len;
2486                 if (ext_depth(inode) > sbi->s_depth_max)
2487                         sbi->s_depth_max = ext_depth(inode);
2488                 spin_unlock(&sbi->s_ext_stats_lock);
2489         }
2490 #endif
2491         if (from >= le32_to_cpu(ex->ee_block)
2492             && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2493                 /* tail removal */
2494                 ext4_lblk_t num;
2495                 unsigned int unaligned;
2496
2497                 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2498                 pblk = ext4_ext_pblock(ex) + ee_len - num;
2499                 /*
2500                  * Usually we want to free partial cluster at the end of the
2501                  * extent, except for the situation when the cluster is still
2502                  * used by any other extent (partial_cluster is negative).
2503                  */
2504                 if (*partial_cluster < 0 &&
2505                     -(*partial_cluster) == EXT4_B2C(sbi, pblk + num - 1))
2506                         flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2507
2508                 ext_debug("free last %u blocks starting %llu partial %lld\n",
2509                           num, pblk, *partial_cluster);
2510                 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2511                 /*
2512                  * If the block range to be freed didn't start at the
2513                  * beginning of a cluster, and we removed the entire
2514                  * extent and the cluster is not used by any other extent,
2515                  * save the partial cluster here, since we might need to
2516                  * delete if we determine that the truncate operation has
2517                  * removed all of the blocks in the cluster.
2518                  *
2519                  * On the other hand, if we did not manage to free the whole
2520                  * extent, we have to mark the cluster as used (store negative
2521                  * cluster number in partial_cluster).
2522                  */
2523                 unaligned = EXT4_PBLK_COFF(sbi, pblk);
2524                 if (unaligned && (ee_len == num) &&
2525                     (*partial_cluster != -((long long)EXT4_B2C(sbi, pblk))))
2526                         *partial_cluster = EXT4_B2C(sbi, pblk);
2527                 else if (unaligned)
2528                         *partial_cluster = -((long long)EXT4_B2C(sbi, pblk));
2529                 else if (*partial_cluster > 0)
2530                         *partial_cluster = 0;
2531         } else
2532                 ext4_error(sbi->s_sb, "strange request: removal(2) "
2533                            "%u-%u from %u:%u\n",
2534                            from, to, le32_to_cpu(ex->ee_block), ee_len);
2535         return 0;
2536 }
2537
2538
2539 /*
2540  * ext4_ext_rm_leaf() Removes the extents associated with the
2541  * blocks appearing between "start" and "end", and splits the extents
2542  * if "start" and "end" appear in the same extent
2543  *
2544  * @handle: The journal handle
2545  * @inode:  The files inode
2546  * @path:   The path to the leaf
2547  * @partial_cluster: The cluster which we'll have to free if all extents
2548  *                   has been released from it. It gets negative in case
2549  *                   that the cluster is still used.
2550  * @start:  The first block to remove
2551  * @end:   The last block to remove
2552  */
2553 static int
2554 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2555                  struct ext4_ext_path *path,
2556                  long long *partial_cluster,
2557                  ext4_lblk_t start, ext4_lblk_t end)
2558 {
2559         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2560         int err = 0, correct_index = 0;
2561         int depth = ext_depth(inode), credits;
2562         struct ext4_extent_header *eh;
2563         ext4_lblk_t a, b;
2564         unsigned num;
2565         ext4_lblk_t ex_ee_block;
2566         unsigned short ex_ee_len;
2567         unsigned uninitialized = 0;
2568         struct ext4_extent *ex;
2569         ext4_fsblk_t pblk;
2570
2571         /* the header must be checked already in ext4_ext_remove_space() */
2572         ext_debug("truncate since %u in leaf to %u\n", start, end);
2573         if (!path[depth].p_hdr)
2574                 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2575         eh = path[depth].p_hdr;
2576         if (unlikely(path[depth].p_hdr == NULL)) {
2577                 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2578                 return -EIO;
2579         }
2580         /* find where to start removing */
2581         ex = path[depth].p_ext;
2582         if (!ex)
2583                 ex = EXT_LAST_EXTENT(eh);
2584
2585         ex_ee_block = le32_to_cpu(ex->ee_block);
2586         ex_ee_len = ext4_ext_get_actual_len(ex);
2587
2588         trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2589
2590         while (ex >= EXT_FIRST_EXTENT(eh) &&
2591                         ex_ee_block + ex_ee_len > start) {
2592
2593                 if (ext4_ext_is_uninitialized(ex))
2594                         uninitialized = 1;
2595                 else
2596                         uninitialized = 0;
2597
2598                 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2599                          uninitialized, ex_ee_len);
2600                 path[depth].p_ext = ex;
2601
2602                 a = ex_ee_block > start ? ex_ee_block : start;
2603                 b = ex_ee_block+ex_ee_len - 1 < end ?
2604                         ex_ee_block+ex_ee_len - 1 : end;
2605
2606                 ext_debug("  border %u:%u\n", a, b);
2607
2608                 /* If this extent is beyond the end of the hole, skip it */
2609                 if (end < ex_ee_block) {
2610                         /*
2611                          * We're going to skip this extent and move to another,
2612                          * so if this extent is not cluster aligned we have
2613                          * to mark the current cluster as used to avoid
2614                          * accidentally freeing it later on
2615                          */
2616                         pblk = ext4_ext_pblock(ex);
2617                         if (EXT4_PBLK_COFF(sbi, pblk))
2618                                 *partial_cluster =
2619                                         -((long long)EXT4_B2C(sbi, pblk));
2620                         ex--;
2621                         ex_ee_block = le32_to_cpu(ex->ee_block);
2622                         ex_ee_len = ext4_ext_get_actual_len(ex);
2623                         continue;
2624                 } else if (b != ex_ee_block + ex_ee_len - 1) {
2625                         EXT4_ERROR_INODE(inode,
2626                                          "can not handle truncate %u:%u "
2627                                          "on extent %u:%u",
2628                                          start, end, ex_ee_block,
2629                                          ex_ee_block + ex_ee_len - 1);
2630                         err = -EIO;
2631                         goto out;
2632                 } else if (a != ex_ee_block) {
2633                         /* remove tail of the extent */
2634                         num = a - ex_ee_block;
2635                 } else {
2636                         /* remove whole extent: excellent! */
2637                         num = 0;
2638                 }
2639                 /*
2640                  * 3 for leaf, sb, and inode plus 2 (bmap and group
2641                  * descriptor) for each block group; assume two block
2642                  * groups plus ex_ee_len/blocks_per_block_group for
2643                  * the worst case
2644                  */
2645                 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2646                 if (ex == EXT_FIRST_EXTENT(eh)) {
2647                         correct_index = 1;
2648                         credits += (ext_depth(inode)) + 1;
2649                 }
2650                 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2651
2652                 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2653                 if (err)
2654                         goto out;
2655
2656                 err = ext4_ext_get_access(handle, inode, path + depth);
2657                 if (err)
2658                         goto out;
2659
2660                 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2661                                          a, b);
2662                 if (err)
2663                         goto out;
2664
2665                 if (num == 0)
2666                         /* this extent is removed; mark slot entirely unused */
2667                         ext4_ext_store_pblock(ex, 0);
2668
2669                 ex->ee_len = cpu_to_le16(num);
2670                 /*
2671                  * Do not mark uninitialized if all the blocks in the
2672                  * extent have been removed.
2673                  */
2674                 if (uninitialized && num)
2675                         ext4_ext_mark_uninitialized(ex);
2676                 /*
2677                  * If the extent was completely released,
2678                  * we need to remove it from the leaf
2679                  */
2680                 if (num == 0) {
2681                         if (end != EXT_MAX_BLOCKS - 1) {
2682                                 /*
2683                                  * For hole punching, we need to scoot all the
2684                                  * extents up when an extent is removed so that
2685                                  * we dont have blank extents in the middle
2686                                  */
2687                                 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2688                                         sizeof(struct ext4_extent));
2689
2690                                 /* Now get rid of the one at the end */
2691                                 memset(EXT_LAST_EXTENT(eh), 0,
2692                                         sizeof(struct ext4_extent));
2693                         }
2694                         le16_add_cpu(&eh->eh_entries, -1);
2695                 } else if (*partial_cluster > 0)
2696                         *partial_cluster = 0;
2697
2698                 err = ext4_ext_dirty(handle, inode, path + depth);
2699                 if (err)
2700                         goto out;
2701
2702                 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2703                                 ext4_ext_pblock(ex));
2704                 ex--;
2705                 ex_ee_block = le32_to_cpu(ex->ee_block);
2706                 ex_ee_len = ext4_ext_get_actual_len(ex);
2707         }
2708
2709         if (correct_index && eh->eh_entries)
2710                 err = ext4_ext_correct_indexes(handle, inode, path);
2711
2712         /*
2713          * Free the partial cluster only if the current extent does not
2714          * reference it. Otherwise we might free used cluster.
2715          */
2716         if (*partial_cluster > 0 &&
2717             (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
2718              *partial_cluster)) {
2719                 int flags = get_default_free_blocks_flags(inode);
2720
2721                 ext4_free_blocks(handle, inode, NULL,
2722                                  EXT4_C2B(sbi, *partial_cluster),
2723                                  sbi->s_cluster_ratio, flags);
2724                 *partial_cluster = 0;
2725         }
2726
2727         /* if this leaf is free, then we should
2728          * remove it from index block above */
2729         if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2730                 err = ext4_ext_rm_idx(handle, inode, path, depth);
2731
2732 out:
2733         return err;
2734 }
2735
2736 /*
2737  * ext4_ext_more_to_rm:
2738  * returns 1 if current index has to be freed (even partial)
2739  */
2740 static int
2741 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2742 {
2743         BUG_ON(path->p_idx == NULL);
2744
2745         if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2746                 return 0;
2747
2748         /*
2749          * if truncate on deeper level happened, it wasn't partial,
2750          * so we have to consider current index for truncation
2751          */
2752         if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2753                 return 0;
2754         return 1;
2755 }
2756
2757 int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2758                           ext4_lblk_t end)
2759 {
2760         struct super_block *sb = inode->i_sb;
2761         int depth = ext_depth(inode);
2762         struct ext4_ext_path *path = NULL;
2763         long long partial_cluster = 0;
2764         handle_t *handle;
2765         int i = 0, err = 0;
2766
2767         ext_debug("truncate since %u to %u\n", start, end);
2768
2769         /* probably first extent we're gonna free will be last in block */
2770         handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2771         if (IS_ERR(handle))
2772                 return PTR_ERR(handle);
2773
2774 again:
2775         trace_ext4_ext_remove_space(inode, start, end, depth);
2776
2777         /*
2778          * Check if we are removing extents inside the extent tree. If that
2779          * is the case, we are going to punch a hole inside the extent tree
2780          * so we have to check whether we need to split the extent covering
2781          * the last block to remove so we can easily remove the part of it
2782          * in ext4_ext_rm_leaf().
2783          */
2784         if (end < EXT_MAX_BLOCKS - 1) {
2785                 struct ext4_extent *ex;
2786                 ext4_lblk_t ee_block;
2787
2788                 /* find extent for this block */
2789                 path = ext4_ext_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
2790                 if (IS_ERR(path)) {
2791                         ext4_journal_stop(handle);
2792                         return PTR_ERR(path);
2793                 }
2794                 depth = ext_depth(inode);
2795                 /* Leaf not may not exist only if inode has no blocks at all */
2796                 ex = path[depth].p_ext;
2797                 if (!ex) {
2798                         if (depth) {
2799                                 EXT4_ERROR_INODE(inode,
2800                                                  "path[%d].p_hdr == NULL",
2801                                                  depth);
2802                                 err = -EIO;
2803                         }
2804                         goto out;
2805                 }
2806
2807                 ee_block = le32_to_cpu(ex->ee_block);
2808
2809                 /*
2810                  * See if the last block is inside the extent, if so split
2811                  * the extent at 'end' block so we can easily remove the
2812                  * tail of the first part of the split extent in
2813                  * ext4_ext_rm_leaf().
2814                  */
2815                 if (end >= ee_block &&
2816                     end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
2817                         int split_flag = 0;
2818
2819                         if (ext4_ext_is_uninitialized(ex))
2820                                 split_flag = EXT4_EXT_MARK_UNINIT1 |
2821                                              EXT4_EXT_MARK_UNINIT2;
2822
2823                         /*
2824                          * Split the extent in two so that 'end' is the last
2825                          * block in the first new extent. Also we should not
2826                          * fail removing space due to ENOSPC so try to use
2827                          * reserved block if that happens.
2828                          */
2829                         err = ext4_split_extent_at(handle, inode, path,
2830                                         end + 1, split_flag,
2831                                         EXT4_EX_NOCACHE |
2832                                         EXT4_GET_BLOCKS_PRE_IO |
2833                                         EXT4_GET_BLOCKS_METADATA_NOFAIL);
2834
2835                         if (err < 0)
2836                                 goto out;
2837                 }
2838         }
2839         /*
2840          * We start scanning from right side, freeing all the blocks
2841          * after i_size and walking into the tree depth-wise.
2842          */
2843         depth = ext_depth(inode);
2844         if (path) {
2845                 int k = i = depth;
2846                 while (--k > 0)
2847                         path[k].p_block =
2848                                 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2849         } else {
2850                 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2851                                GFP_NOFS);
2852                 if (path == NULL) {
2853                         ext4_journal_stop(handle);
2854                         return -ENOMEM;
2855                 }
2856                 path[0].p_depth = depth;
2857                 path[0].p_hdr = ext_inode_hdr(inode);
2858                 i = 0;
2859
2860                 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2861                         err = -EIO;
2862                         goto out;
2863                 }
2864         }
2865         err = 0;
2866
2867         while (i >= 0 && err == 0) {
2868                 if (i == depth) {
2869                         /* this is leaf block */
2870                         err = ext4_ext_rm_leaf(handle, inode, path,
2871                                                &partial_cluster, start,
2872                                                end);
2873                         /* root level has p_bh == NULL, brelse() eats this */
2874                         brelse(path[i].p_bh);
2875                         path[i].p_bh = NULL;
2876                         i--;
2877                         continue;
2878                 }
2879
2880                 /* this is index block */
2881                 if (!path[i].p_hdr) {
2882                         ext_debug("initialize header\n");
2883                         path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2884                 }
2885
2886                 if (!path[i].p_idx) {
2887                         /* this level hasn't been touched yet */
2888                         path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2889                         path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2890                         ext_debug("init index ptr: hdr 0x%p, num %d\n",
2891                                   path[i].p_hdr,
2892                                   le16_to_cpu(path[i].p_hdr->eh_entries));
2893                 } else {
2894                         /* we were already here, see at next index */
2895                         path[i].p_idx--;
2896                 }
2897
2898                 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2899                                 i, EXT_FIRST_INDEX(path[i].p_hdr),
2900                                 path[i].p_idx);
2901                 if (ext4_ext_more_to_rm(path + i)) {
2902                         struct buffer_head *bh;
2903                         /* go to the next level */
2904                         ext_debug("move to level %d (block %llu)\n",
2905                                   i + 1, ext4_idx_pblock(path[i].p_idx));
2906                         memset(path + i + 1, 0, sizeof(*path));
2907                         bh = read_extent_tree_block(inode,
2908                                 ext4_idx_pblock(path[i].p_idx), depth - i - 1,
2909                                 EXT4_EX_NOCACHE);
2910                         if (IS_ERR(bh)) {
2911                                 /* should we reset i_size? */
2912                                 err = PTR_ERR(bh);
2913                                 break;
2914                         }
2915                         /* Yield here to deal with large extent trees.
2916                          * Should be a no-op if we did IO above. */
2917                         cond_resched();
2918                         if (WARN_ON(i + 1 > depth)) {
2919                                 err = -EIO;
2920                                 break;
2921                         }
2922                         path[i + 1].p_bh = bh;
2923
2924                         /* save actual number of indexes since this
2925                          * number is changed at the next iteration */
2926                         path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2927                         i++;
2928                 } else {
2929                         /* we finished processing this index, go up */
2930                         if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2931                                 /* index is empty, remove it;
2932                                  * handle must be already prepared by the
2933                                  * truncatei_leaf() */
2934                                 err = ext4_ext_rm_idx(handle, inode, path, i);
2935                         }
2936                         /* root level has p_bh == NULL, brelse() eats this */
2937                         brelse(path[i].p_bh);
2938                         path[i].p_bh = NULL;
2939                         i--;
2940                         ext_debug("return to level %d\n", i);
2941                 }
2942         }
2943
2944         trace_ext4_ext_remove_space_done(inode, start, end, depth,
2945                         partial_cluster, path->p_hdr->eh_entries);
2946
2947         /* If we still have something in the partial cluster and we have removed
2948          * even the first extent, then we should free the blocks in the partial
2949          * cluster as well. */
2950         if (partial_cluster > 0 && path->p_hdr->eh_entries == 0) {
2951                 int flags = get_default_free_blocks_flags(inode);
2952
2953                 ext4_free_blocks(handle, inode, NULL,
2954                                  EXT4_C2B(EXT4_SB(sb), partial_cluster),
2955                                  EXT4_SB(sb)->s_cluster_ratio, flags);
2956                 partial_cluster = 0;
2957         }
2958
2959         /* TODO: flexible tree reduction should be here */
2960         if (path->p_hdr->eh_entries == 0) {
2961                 /*
2962                  * truncate to zero freed all the tree,
2963                  * so we need to correct eh_depth
2964                  */
2965                 err = ext4_ext_get_access(handle, inode, path);
2966                 if (err == 0) {
2967                         ext_inode_hdr(inode)->eh_depth = 0;
2968                         ext_inode_hdr(inode)->eh_max =
2969                                 cpu_to_le16(ext4_ext_space_root(inode, 0));
2970                         err = ext4_ext_dirty(handle, inode, path);
2971                 }
2972         }
2973 out:
2974         ext4_ext_drop_refs(path);
2975         kfree(path);
2976         if (err == -EAGAIN) {
2977                 path = NULL;
2978                 goto again;
2979         }
2980         ext4_journal_stop(handle);
2981
2982         return err;
2983 }
2984
2985 /*
2986  * called at mount time
2987  */
2988 void ext4_ext_init(struct super_block *sb)
2989 {
2990         /*
2991          * possible initialization would be here
2992          */
2993
2994         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2995 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
2996                 printk(KERN_INFO "EXT4-fs: file extents enabled"
2997 #ifdef AGGRESSIVE_TEST
2998                        ", aggressive tests"
2999 #endif
3000 #ifdef CHECK_BINSEARCH
3001                        ", check binsearch"
3002 #endif
3003 #ifdef EXTENTS_STATS
3004                        ", stats"
3005 #endif
3006                        "\n");
3007 #endif
3008 #ifdef EXTENTS_STATS
3009                 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3010                 EXT4_SB(sb)->s_ext_min = 1 << 30;
3011                 EXT4_SB(sb)->s_ext_max = 0;
3012 #endif
3013         }
3014 }
3015
3016 /*
3017  * called at umount time
3018  */
3019 void ext4_ext_release(struct super_block *sb)
3020 {
3021         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3022                 return;
3023
3024 #ifdef EXTENTS_STATS
3025         if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3026                 struct ext4_sb_info *sbi = EXT4_SB(sb);
3027                 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3028                         sbi->s_ext_blocks, sbi->s_ext_extents,
3029                         sbi->s_ext_blocks / sbi->s_ext_extents);
3030                 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3031                         sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3032         }
3033 #endif
3034 }
3035
3036 static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3037 {
3038         ext4_lblk_t  ee_block;
3039         ext4_fsblk_t ee_pblock;
3040         unsigned int ee_len;
3041
3042         ee_block  = le32_to_cpu(ex->ee_block);
3043         ee_len    = ext4_ext_get_actual_len(ex);
3044         ee_pblock = ext4_ext_pblock(ex);
3045
3046         if (ee_len == 0)
3047                 return 0;
3048
3049         return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3050                                      EXTENT_STATUS_WRITTEN);
3051 }
3052
3053 /* FIXME!! we need to try to merge to left or right after zero-out  */
3054 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3055 {
3056         ext4_fsblk_t ee_pblock;
3057         unsigned int ee_len;
3058         int ret;
3059
3060         ee_len    = ext4_ext_get_actual_len(ex);
3061         ee_pblock = ext4_ext_pblock(ex);
3062
3063         ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
3064         if (ret > 0)
3065                 ret = 0;
3066
3067         return ret;
3068 }
3069
3070 /*
3071  * ext4_split_extent_at() splits an extent at given block.
3072  *
3073  * @handle: the journal handle
3074  * @inode: the file inode
3075  * @path: the path to the extent
3076  * @split: the logical block where the extent is splitted.
3077  * @split_flags: indicates if the extent could be zeroout if split fails, and
3078  *               the states(init or uninit) of new extents.
3079  * @flags: flags used to insert new extent to extent tree.
3080  *
3081  *
3082  * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3083  * of which are deterimined by split_flag.
3084  *
3085  * There are two cases:
3086  *  a> the extent are splitted into two extent.
3087  *  b> split is not needed, and just mark the extent.
3088  *
3089  * return 0 on success.
3090  */
3091 static int ext4_split_extent_at(handle_t *handle,
3092                              struct inode *inode,
3093                              struct ext4_ext_path *path,
3094                              ext4_lblk_t split,
3095                              int split_flag,
3096                              int flags)
3097 {
3098         ext4_fsblk_t newblock;
3099         ext4_lblk_t ee_block;
3100         struct ext4_extent *ex, newex, orig_ex, zero_ex;
3101         struct ext4_extent *ex2 = NULL;
3102         unsigned int ee_len, depth;
3103         int err = 0;
3104
3105         BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3106                (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3107
3108         ext_debug("ext4_split_extents_at: inode %lu, logical"
3109                 "block %llu\n", inode->i_ino, (unsigned long long)split);
3110
3111         ext4_ext_show_leaf(inode, path);
3112
3113         depth = ext_depth(inode);
3114         ex = path[depth].p_ext;
3115         ee_block = le32_to_cpu(ex->ee_block);
3116         ee_len = ext4_ext_get_actual_len(ex);
3117         newblock = split - ee_block + ext4_ext_pblock(ex);
3118
3119         BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3120         BUG_ON(!ext4_ext_is_uninitialized(ex) &&
3121                split_flag & (EXT4_EXT_MAY_ZEROOUT |
3122                              EXT4_EXT_MARK_UNINIT1 |
3123                              EXT4_EXT_MARK_UNINIT2));
3124
3125         err = ext4_ext_get_access(handle, inode, path + depth);
3126         if (err)
3127                 goto out;
3128
3129         if (split == ee_block) {
3130                 /*
3131                  * case b: block @split is the block that the extent begins with
3132                  * then we just change the state of the extent, and splitting
3133                  * is not needed.
3134                  */
3135                 if (split_flag & EXT4_EXT_MARK_UNINIT2)
3136                         ext4_ext_mark_uninitialized(ex);
3137                 else
3138                         ext4_ext_mark_initialized(ex);
3139
3140                 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3141                         ext4_ext_try_to_merge(handle, inode, path, ex);
3142
3143                 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3144                 goto out;
3145         }
3146
3147         /* case a */
3148         memcpy(&orig_ex, ex, sizeof(orig_ex));
3149         ex->ee_len = cpu_to_le16(split - ee_block);
3150         if (split_flag & EXT4_EXT_MARK_UNINIT1)
3151                 ext4_ext_mark_uninitialized(ex);
3152
3153         /*
3154          * path may lead to new leaf, not to original leaf any more
3155          * after ext4_ext_insert_extent() returns,
3156          */
3157         err = ext4_ext_dirty(handle, inode, path + depth);
3158         if (err)
3159                 goto fix_extent_len;
3160
3161         ex2 = &newex;
3162         ex2->ee_block = cpu_to_le32(split);
3163         ex2->ee_len   = cpu_to_le16(ee_len - (split - ee_block));
3164         ext4_ext_store_pblock(ex2, newblock);
3165         if (split_flag & EXT4_EXT_MARK_UNINIT2)
3166                 ext4_ext_mark_uninitialized(ex2);
3167
3168         err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
3169         if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3170                 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3171                         if (split_flag & EXT4_EXT_DATA_VALID1) {
3172                                 err = ext4_ext_zeroout(inode, ex2);
3173                                 zero_ex.ee_block = ex2->ee_block;
3174                                 zero_ex.ee_len = cpu_to_le16(
3175                                                 ext4_ext_get_actual_len(ex2));
3176                                 ext4_ext_store_pblock(&zero_ex,
3177                                                       ext4_ext_pblock(ex2));
3178                         } else {
3179                                 err = ext4_ext_zeroout(inode, ex);
3180                                 zero_ex.ee_block = ex->ee_block;
3181                                 zero_ex.ee_len = cpu_to_le16(
3182                                                 ext4_ext_get_actual_len(ex));
3183                                 ext4_ext_store_pblock(&zero_ex,
3184                                                       ext4_ext_pblock(ex));
3185                         }
3186                 } else {
3187                         err = ext4_ext_zeroout(inode, &orig_ex);
3188                         zero_ex.ee_block = orig_ex.ee_block;
3189                         zero_ex.ee_len = cpu_to_le16(
3190                                                 ext4_ext_get_actual_len(&orig_ex));
3191                         ext4_ext_store_pblock(&zero_ex,
3192                                               ext4_ext_pblock(&orig_ex));
3193                 }
3194
3195                 if (err)
3196                         goto fix_extent_len;
3197                 /* update the extent length and mark as initialized */
3198                 ex->ee_len = cpu_to_le16(ee_len);
3199                 ext4_ext_try_to_merge(handle, inode, path, ex);
3200                 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3201                 if (err)
3202                         goto fix_extent_len;
3203
3204                 /* update extent status tree */
3205                 err = ext4_zeroout_es(inode, &zero_ex);
3206
3207                 goto out;
3208         } else if (err)
3209                 goto fix_extent_len;
3210
3211 out:
3212         ext4_ext_show_leaf(inode, path);
3213         return err;
3214
3215 fix_extent_len:
3216         ex->ee_len = orig_ex.ee_len;
3217         ext4_ext_dirty(handle, inode, path + depth);
3218         return err;
3219 }
3220
3221 /*
3222  * ext4_split_extents() splits an extent and mark extent which is covered
3223  * by @map as split_flags indicates
3224  *
3225  * It may result in splitting the extent into multiple extents (up to three)
3226  * There are three possibilities:
3227  *   a> There is no split required
3228  *   b> Splits in two extents: Split is happening at either end of the extent
3229  *   c> Splits in three extents: Somone is splitting in middle of the extent
3230  *
3231  */
3232 static int ext4_split_extent(handle_t *handle,
3233                               struct inode *inode,
3234                               struct ext4_ext_path *path,
3235                               struct ext4_map_blocks *map,
3236                               int split_flag,
3237                               int flags)
3238 {
3239         ext4_lblk_t ee_block;
3240         struct ext4_extent *ex;
3241         unsigned int ee_len, depth;
3242         int err = 0;
3243         int uninitialized;
3244         int split_flag1, flags1;
3245         int allocated = map->m_len;
3246
3247         depth = ext_depth(inode);
3248         ex = path[depth].p_ext;
3249         ee_block = le32_to_cpu(ex->ee_block);
3250         ee_len = ext4_ext_get_actual_len(ex);
3251         uninitialized = ext4_ext_is_uninitialized(ex);
3252
3253         if (map->m_lblk + map->m_len < ee_block + ee_len) {
3254                 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3255                 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3256                 if (uninitialized)
3257                         split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
3258                                        EXT4_EXT_MARK_UNINIT2;
3259                 if (split_flag & EXT4_EXT_DATA_VALID2)
3260                         split_flag1 |= EXT4_EXT_DATA_VALID1;
3261                 err = ext4_split_extent_at(handle, inode, path,
3262                                 map->m_lblk + map->m_len, split_flag1, flags1);
3263                 if (err)
3264                         goto out;
3265         } else {
3266                 allocated = ee_len - (map->m_lblk - ee_block);
3267         }
3268         /*
3269          * Update path is required because previous ext4_split_extent_at() may
3270          * result in split of original leaf or extent zeroout.
3271          */
3272         ext4_ext_drop_refs(path);
3273         path = ext4_ext_find_extent(inode, map->m_lblk, path, 0);
3274         if (IS_ERR(path))
3275                 return PTR_ERR(path);
3276         depth = ext_depth(inode);
3277         ex = path[depth].p_ext;
3278         uninitialized = ext4_ext_is_uninitialized(ex);
3279         split_flag1 = 0;
3280
3281         if (map->m_lblk >= ee_block) {
3282                 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3283                 if (uninitialized) {
3284                         split_flag1 |= EXT4_EXT_MARK_UNINIT1;
3285                         split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3286                                                      EXT4_EXT_MARK_UNINIT2);
3287                 }
3288                 err = ext4_split_extent_at(handle, inode, path,
3289                                 map->m_lblk, split_flag1, flags);
3290                 if (err)
3291                         goto out;
3292         }
3293
3294         ext4_ext_show_leaf(inode, path);
3295 out:
3296         return err ? err : allocated;
3297 }
3298
3299 /*
3300  * This function is called by ext4_ext_map_blocks() if someone tries to write
3301  * to an uninitialized extent. It may result in splitting the uninitialized
3302  * extent into multiple extents (up to three - one initialized and two
3303  * uninitialized).
3304  * There are three possibilities:
3305  *   a> There is no split required: Entire extent should be initialized
3306  *   b> Splits in two extents: Write is happening at either end of the extent
3307  *   c> Splits in three extents: Somone is writing in middle of the extent
3308  *
3309  * Pre-conditions:
3310  *  - The extent pointed to by 'path' is uninitialized.
3311  *  - The extent pointed to by 'path' contains a superset
3312  *    of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3313  *
3314  * Post-conditions on success:
3315  *  - the returned value is the number of blocks beyond map->l_lblk
3316  *    that are allocated and initialized.
3317  *    It is guaranteed to be >= map->m_len.
3318  */
3319 static int ext4_ext_convert_to_initialized(handle_t *handle,
3320                                            struct inode *inode,
3321                                            struct ext4_map_blocks *map,
3322                                            struct ext4_ext_path *path,
3323                                            int flags)
3324 {
3325         struct ext4_sb_info *sbi;
3326         struct ext4_extent_header *eh;
3327         struct ext4_map_blocks split_map;
3328         struct ext4_extent zero_ex;
3329         struct ext4_extent *ex, *abut_ex;
3330         ext4_lblk_t ee_block, eof_block;
3331         unsigned int ee_len, depth, map_len = map->m_len;
3332         int allocated = 0, max_zeroout = 0;
3333         int err = 0;
3334         int split_flag = 0;
3335
3336         ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3337                 "block %llu, max_blocks %u\n", inode->i_ino,
3338                 (unsigned long long)map->m_lblk, map_len);
3339
3340         sbi = EXT4_SB(inode->i_sb);
3341         eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3342                 inode->i_sb->s_blocksize_bits;
3343         if (eof_block < map->m_lblk + map_len)
3344                 eof_block = map->m_lblk + map_len;
3345
3346         depth = ext_depth(inode);
3347         eh = path[depth].p_hdr;
3348         ex = path[depth].p_ext;
3349         ee_block = le32_to_cpu(ex->ee_block);
3350         ee_len = ext4_ext_get_actual_len(ex);
3351         zero_ex.ee_len = 0;
3352
3353         trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3354
3355         /* Pre-conditions */
3356         BUG_ON(!ext4_ext_is_uninitialized(ex));
3357         BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3358
3359         /*
3360          * Attempt to transfer newly initialized blocks from the currently
3361          * uninitialized extent to its neighbor. This is much cheaper
3362          * than an insertion followed by a merge as those involve costly
3363          * memmove() calls. Transferring to the left is the common case in
3364          * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3365          * followed by append writes.
3366          *
3367          * Limitations of the current logic:
3368          *  - L1: we do not deal with writes covering the whole extent.
3369          *    This would require removing the extent if the transfer
3370          *    is possible.
3371          *  - L2: we only attempt to merge with an extent stored in the
3372          *    same extent tree node.
3373          */
3374         if ((map->m_lblk == ee_block) &&
3375                 /* See if we can merge left */
3376                 (map_len < ee_len) &&           /*L1*/
3377                 (ex > EXT_FIRST_EXTENT(eh))) {  /*L2*/
3378                 ext4_lblk_t prev_lblk;
3379                 ext4_fsblk_t prev_pblk, ee_pblk;
3380                 unsigned int prev_len;
3381
3382                 abut_ex = ex - 1;
3383                 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3384                 prev_len = ext4_ext_get_actual_len(abut_ex);
3385                 prev_pblk = ext4_ext_pblock(abut_ex);
3386                 ee_pblk = ext4_ext_pblock(ex);
3387
3388                 /*
3389                  * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3390                  * upon those conditions:
3391                  * - C1: abut_ex is initialized,
3392                  * - C2: abut_ex is logically abutting ex,
3393                  * - C3: abut_ex is physically abutting ex,
3394                  * - C4: abut_ex can receive the additional blocks without
3395                  *   overflowing the (initialized) length limit.
3396                  */
3397                 if ((!ext4_ext_is_uninitialized(abut_ex)) &&            /*C1*/
3398                         ((prev_lblk + prev_len) == ee_block) &&         /*C2*/
3399                         ((prev_pblk + prev_len) == ee_pblk) &&          /*C3*/
3400                         (prev_len < (EXT_INIT_MAX_LEN - map_len))) {    /*C4*/
3401                         err = ext4_ext_get_access(handle, inode, path + depth);
3402                         if (err)
3403                                 goto out;
3404
3405                         trace_ext4_ext_convert_to_initialized_fastpath(inode,
3406                                 map, ex, abut_ex);
3407
3408                         /* Shift the start of ex by 'map_len' blocks */
3409                         ex->ee_block = cpu_to_le32(ee_block + map_len);
3410                         ext4_ext_store_pblock(ex, ee_pblk + map_len);
3411                         ex->ee_len = cpu_to_le16(ee_len - map_len);
3412                         ext4_ext_mark_uninitialized(ex); /* Restore the flag */
3413
3414                         /* Extend abut_ex by 'map_len' blocks */
3415                         abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3416
3417                         /* Result: number of initialized blocks past m_lblk */
3418                         allocated = map_len;
3419                 }
3420         } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3421                    (map_len < ee_len) &&        /*L1*/
3422                    ex < EXT_LAST_EXTENT(eh)) {  /*L2*/
3423                 /* See if we can merge right */
3424                 ext4_lblk_t next_lblk;
3425                 ext4_fsblk_t next_pblk, ee_pblk;
3426                 unsigned int next_len;
3427
3428                 abut_ex = ex + 1;
3429                 next_lblk = le32_to_cpu(abut_ex->ee_block);
3430                 next_len = ext4_ext_get_actual_len(abut_ex);
3431                 next_pblk = ext4_ext_pblock(abut_ex);
3432                 ee_pblk = ext4_ext_pblock(ex);
3433
3434                 /*
3435                  * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3436                  * upon those conditions:
3437                  * - C1: abut_ex is initialized,
3438                  * - C2: abut_ex is logically abutting ex,
3439                  * - C3: abut_ex is physically abutting ex,
3440                  * - C4: abut_ex can receive the additional blocks without
3441                  *   overflowing the (initialized) length limit.
3442                  */
3443                 if ((!ext4_ext_is_uninitialized(abut_ex)) &&            /*C1*/
3444                     ((map->m_lblk + map_len) == next_lblk) &&           /*C2*/
3445                     ((ee_pblk + ee_len) == next_pblk) &&                /*C3*/
3446                     (next_len < (EXT_INIT_MAX_LEN - map_len))) {        /*C4*/
3447                         err = ext4_ext_get_access(handle, inode, path + depth);
3448                         if (err)
3449                                 goto out;
3450
3451                         trace_ext4_ext_convert_to_initialized_fastpath(inode,
3452                                 map, ex, abut_ex);
3453
3454                         /* Shift the start of abut_ex by 'map_len' blocks */
3455                         abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3456                         ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3457                         ex->ee_len = cpu_to_le16(ee_len - map_len);
3458                         ext4_ext_mark_uninitialized(ex); /* Restore the flag */
3459
3460                         /* Extend abut_ex by 'map_len' blocks */
3461                         abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3462
3463                         /* Result: number of initialized blocks past m_lblk */
3464                         allocated = map_len;
3465                 }
3466         }
3467         if (allocated) {
3468                 /* Mark the block containing both extents as dirty */
3469                 ext4_ext_dirty(handle, inode, path + depth);
3470
3471                 /* Update path to point to the right extent */
3472                 path[depth].p_ext = abut_ex;
3473                 goto out;
3474         } else
3475                 allocated = ee_len - (map->m_lblk - ee_block);
3476
3477         WARN_ON(map->m_lblk < ee_block);
3478         /*
3479          * It is safe to convert extent to initialized via explicit
3480          * zeroout only if extent is fully inside i_size or new_size.
3481          */
3482         split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3483
3484         if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3485                 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3486                         (inode->i_sb->s_blocksize_bits - 10);
3487
3488         /* If extent is less than s_max_zeroout_kb, zeroout directly */
3489         if (max_zeroout && (ee_len <= max_zeroout)) {
3490                 err = ext4_ext_zeroout(inode, ex);
3491                 if (err)
3492                         goto out;
3493                 zero_ex.ee_block = ex->ee_block;
3494                 zero_ex.ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex));
3495                 ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
3496
3497                 err = ext4_ext_get_access(handle, inode, path + depth);
3498                 if (err)
3499                         goto out;
3500                 ext4_ext_mark_initialized(ex);
3501                 ext4_ext_try_to_merge(handle, inode, path, ex);
3502                 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3503                 goto out;
3504         }
3505
3506         /*
3507          * four cases:
3508          * 1. split the extent into three extents.
3509          * 2. split the extent into two extents, zeroout the first half.
3510          * 3. split the extent into two extents, zeroout the second half.
3511          * 4. split the extent into two extents with out zeroout.
3512          */
3513         split_map.m_lblk = map->m_lblk;
3514         split_map.m_len = map->m_len;
3515
3516         if (max_zeroout && (allocated > map->m_len)) {
3517                 if (allocated <= max_zeroout) {
3518                         /* case 3 */
3519                         zero_ex.ee_block =
3520                                          cpu_to_le32(map->m_lblk);
3521                         zero_ex.ee_len = cpu_to_le16(allocated);
3522                         ext4_ext_store_pblock(&zero_ex,
3523                                 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3524                         err = ext4_ext_zeroout(inode, &zero_ex);
3525                         if (err)
3526                                 goto out;
3527                         split_map.m_lblk = map->m_lblk;
3528                         split_map.m_len = allocated;
3529                 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3530                         /* case 2 */
3531                         if (map->m_lblk != ee_block) {
3532                                 zero_ex.ee_block = ex->ee_block;
3533                                 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3534                                                         ee_block);
3535                                 ext4_ext_store_pblock(&zero_ex,
3536                                                       ext4_ext_pblock(ex));
3537                                 err = ext4_ext_zeroout(inode, &zero_ex);
3538                                 if (err)
3539                                         goto out;
3540                         }
3541
3542                         split_map.m_lblk = ee_block;
3543                         split_map.m_len = map->m_lblk - ee_block + map->m_len;
3544                         allocated = map->m_len;
3545                 }
3546         }
3547
3548         allocated = ext4_split_extent(handle, inode, path,
3549                                       &split_map, split_flag, flags);
3550         if (allocated < 0)
3551                 err = allocated;
3552
3553 out:
3554         /* If we have gotten a failure, don't zero out status tree */
3555         if (!err)
3556                 err = ext4_zeroout_es(inode, &zero_ex);
3557         return err ? err : allocated;
3558 }
3559
3560 /*
3561  * This function is called by ext4_ext_map_blocks() from
3562  * ext4_get_blocks_dio_write() when DIO to write
3563  * to an uninitialized extent.
3564  *
3565  * Writing to an uninitialized extent may result in splitting the uninitialized
3566  * extent into multiple initialized/uninitialized extents (up to three)
3567  * There are three possibilities:
3568  *   a> There is no split required: Entire extent should be uninitialized
3569  *   b> Splits in two extents: Write is happening at either end of the extent
3570  *   c> Splits in three extents: Somone is writing in middle of the extent
3571  *
3572  * One of more index blocks maybe needed if the extent tree grow after
3573  * the uninitialized extent split. To prevent ENOSPC occur at the IO
3574  * complete, we need to split the uninitialized extent before DIO submit
3575  * the IO. The uninitialized extent called at this time will be split
3576  * into three uninitialized extent(at most). After IO complete, the part
3577  * being filled will be convert to initialized by the end_io callback function
3578  * via ext4_convert_unwritten_extents().
3579  *
3580  * Returns the size of uninitialized extent to be written on success.
3581  */
3582 static int ext4_split_unwritten_extents(handle_t *handle,
3583                                         struct inode *inode,
3584                                         struct ext4_map_blocks *map,
3585                                         struct ext4_ext_path *path,
3586                                         int flags)
3587 {
3588         ext4_lblk_t eof_block;
3589         ext4_lblk_t ee_block;
3590         struct ext4_extent *ex;
3591         unsigned int ee_len;
3592         int split_flag = 0, depth;
3593
3594         ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
3595                 "block %llu, max_blocks %u\n", inode->i_ino,
3596                 (unsigned long long)map->m_lblk, map->m_len);
3597
3598         eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3599                 inode->i_sb->s_blocksize_bits;
3600         if (eof_block < map->m_lblk + map->m_len)
3601                 eof_block = map->m_lblk + map->m_len;
3602         /*
3603          * It is safe to convert extent to initialized via explicit
3604          * zeroout only if extent is fully insde i_size or new_size.
3605          */
3606         depth = ext_depth(inode);
3607         ex = path[depth].p_ext;
3608         ee_block = le32_to_cpu(ex->ee_block);
3609         ee_len = ext4_ext_get_actual_len(ex);
3610
3611         split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3612         split_flag |= EXT4_EXT_MARK_UNINIT2;
3613         if (flags & EXT4_GET_BLOCKS_CONVERT)
3614                 split_flag |= EXT4_EXT_DATA_VALID2;
3615         flags |= EXT4_GET_BLOCKS_PRE_IO;
3616         return ext4_split_extent(handle, inode, path, map, split_flag, flags);
3617 }
3618
3619 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3620                                                 struct inode *inode,
3621                                                 struct ext4_map_blocks *map,
3622                                                 struct ext4_ext_path *path)
3623 {
3624         struct ext4_extent *ex;
3625         ext4_lblk_t ee_block;
3626         unsigned int ee_len;
3627         int depth;
3628         int err = 0;
3629
3630         depth = ext_depth(inode);
3631         ex = path[depth].p_ext;
3632         ee_block = le32_to_cpu(ex->ee_block);
3633         ee_len = ext4_ext_get_actual_len(ex);
3634
3635         ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3636                 "block %llu, max_blocks %u\n", inode->i_ino,
3637                   (unsigned long long)ee_block, ee_len);
3638
3639         /* If extent is larger than requested it is a clear sign that we still
3640          * have some extent state machine issues left. So extent_split is still
3641          * required.
3642          * TODO: Once all related issues will be fixed this situation should be
3643          * illegal.
3644          */
3645         if (ee_block != map->m_lblk || ee_len > map->m_len) {
3646 #ifdef EXT4_DEBUG
3647                 ext4_warning("Inode (%ld) finished: extent logical block %llu,"
3648                              " len %u; IO logical block %llu, len %u\n",
3649                              inode->i_ino, (unsigned long long)ee_block, ee_len,
3650                              (unsigned long long)map->m_lblk, map->m_len);
3651 #endif
3652                 err = ext4_split_unwritten_extents(handle, inode, map, path,
3653                                                    EXT4_GET_BLOCKS_CONVERT);
3654                 if (err < 0)
3655                         goto out;
3656                 ext4_ext_drop_refs(path);
3657                 path = ext4_ext_find_extent(inode, map->m_lblk, path, 0);
3658                 if (IS_ERR(path)) {
3659                         err = PTR_ERR(path);
3660                         goto out;
3661                 }
3662                 depth = ext_depth(inode);
3663                 ex = path[depth].p_ext;
3664         }
3665
3666         err = ext4_ext_get_access(handle, inode, path + depth);
3667         if (err)
3668                 goto out;
3669         /* first mark the extent as initialized */
3670         ext4_ext_mark_initialized(ex);
3671
3672         /* note: ext4_ext_correct_indexes() isn't needed here because
3673          * borders are not changed
3674          */
3675         ext4_ext_try_to_merge(handle, inode, path, ex);
3676
3677         /* Mark modified extent as dirty */
3678         err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3679 out:
3680         ext4_ext_show_leaf(inode, path);
3681         return err;
3682 }
3683
3684 static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3685                         sector_t block, int count)
3686 {
3687         int i;
3688         for (i = 0; i < count; i++)
3689                 unmap_underlying_metadata(bdev, block + i);
3690 }
3691
3692 /*
3693  * Handle EOFBLOCKS_FL flag, clearing it if necessary
3694  */
3695 static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3696                               ext4_lblk_t lblk,
3697                               struct ext4_ext_path *path,
3698                               unsigned int len)
3699 {
3700         int i, depth;
3701         struct ext4_extent_header *eh;
3702         struct ext4_extent *last_ex;
3703
3704         if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3705                 return 0;
3706
3707         depth = ext_depth(inode);
3708         eh = path[depth].p_hdr;
3709
3710         /*
3711          * We're going to remove EOFBLOCKS_FL entirely in future so we
3712          * do not care for this case anymore. Simply remove the flag
3713          * if there are no extents.
3714          */
3715         if (unlikely(!eh->eh_entries))
3716                 goto out;
3717         last_ex = EXT_LAST_EXTENT(eh);
3718         /*
3719          * We should clear the EOFBLOCKS_FL flag if we are writing the
3720          * last block in the last extent in the file.  We test this by
3721          * first checking to see if the caller to
3722          * ext4_ext_get_blocks() was interested in the last block (or
3723          * a block beyond the last block) in the current extent.  If
3724          * this turns out to be false, we can bail out from this
3725          * function immediately.
3726          */
3727         if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3728             ext4_ext_get_actual_len(last_ex))
3729                 return 0;
3730         /*
3731          * If the caller does appear to be planning to write at or
3732          * beyond the end of the current extent, we then test to see
3733          * if the current extent is the last extent in the file, by
3734          * checking to make sure it was reached via the rightmost node
3735          * at each level of the tree.
3736          */
3737         for (i = depth-1; i >= 0; i--)
3738                 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3739                         return 0;
3740 out:
3741         ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3742         return ext4_mark_inode_dirty(handle, inode);
3743 }
3744
3745 /**
3746  * ext4_find_delalloc_range: find delayed allocated block in the given range.
3747  *
3748  * Return 1 if there is a delalloc block in the range, otherwise 0.
3749  */
3750 int ext4_find_delalloc_range(struct inode *inode,
3751                              ext4_lblk_t lblk_start,
3752                              ext4_lblk_t lblk_end)
3753 {
3754         struct extent_status es;
3755
3756         ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
3757         if (es.es_len == 0)
3758                 return 0; /* there is no delay extent in this tree */
3759         else if (es.es_lblk <= lblk_start &&
3760                  lblk_start < es.es_lblk + es.es_len)
3761                 return 1;
3762         else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3763                 return 1;
3764         else
3765                 return 0;
3766 }
3767
3768 int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3769 {
3770         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3771         ext4_lblk_t lblk_start, lblk_end;
3772         lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
3773         lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3774
3775         return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3776 }
3777
3778 /**
3779  * Determines how many complete clusters (out of those specified by the 'map')
3780  * are under delalloc and were reserved quota for.
3781  * This function is called when we are writing out the blocks that were
3782  * originally written with their allocation delayed, but then the space was
3783  * allocated using fallocate() before the delayed allocation could be resolved.
3784  * The cases to look for are:
3785  * ('=' indicated delayed allocated blocks
3786  *  '-' indicates non-delayed allocated blocks)
3787  * (a) partial clusters towards beginning and/or end outside of allocated range
3788  *     are not delalloc'ed.
3789  *      Ex:
3790  *      |----c---=|====c====|====c====|===-c----|
3791  *               |++++++ allocated ++++++|
3792  *      ==> 4 complete clusters in above example
3793  *
3794  * (b) partial cluster (outside of allocated range) towards either end is
3795  *     marked for delayed allocation. In this case, we will exclude that
3796  *     cluster.
3797  *      Ex:
3798  *      |----====c========|========c========|
3799  *           |++++++ allocated ++++++|
3800  *      ==> 1 complete clusters in above example
3801  *
3802  *      Ex:
3803  *      |================c================|
3804  *            |++++++ allocated ++++++|
3805  *      ==> 0 complete clusters in above example
3806  *
3807  * The ext4_da_update_reserve_space will be called only if we
3808  * determine here that there were some "entire" clusters that span
3809  * this 'allocated' range.
3810  * In the non-bigalloc case, this function will just end up returning num_blks
3811  * without ever calling ext4_find_delalloc_range.
3812  */
3813 static unsigned int
3814 get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3815                            unsigned int num_blks)
3816 {
3817         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3818         ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3819         ext4_lblk_t lblk_from, lblk_to, c_offset;
3820         unsigned int allocated_clusters = 0;
3821
3822         alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3823         alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3824
3825         /* max possible clusters for this allocation */
3826         allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3827
3828         trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3829
3830         /* Check towards left side */
3831         c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
3832         if (c_offset) {
3833                 lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
3834                 lblk_to = lblk_from + c_offset - 1;
3835
3836                 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3837                         allocated_clusters--;
3838         }
3839
3840         /* Now check towards right. */
3841         c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
3842         if (allocated_clusters && c_offset) {
3843                 lblk_from = lblk_start + num_blks;
3844                 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3845
3846                 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3847                         allocated_clusters--;
3848         }
3849
3850         return allocated_clusters;
3851 }
3852
3853 static int
3854 ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
3855                         struct ext4_map_blocks *map,
3856                         struct ext4_ext_path *path, int flags,
3857                         unsigned int allocated, ext4_fsblk_t newblock)
3858 {
3859         int ret = 0;
3860         int err = 0;
3861         ext4_io_end_t *io = ext4_inode_aio(inode);
3862
3863         ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical "
3864                   "block %llu, max_blocks %u, flags %x, allocated %u\n",
3865                   inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
3866                   flags, allocated);
3867         ext4_ext_show_leaf(inode, path);
3868
3869         /*
3870          * When writing into uninitialized space, we should not fail to
3871          * allocate metadata blocks for the new extent block if needed.
3872          */
3873         flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
3874
3875         trace_ext4_ext_handle_uninitialized_extents(inode, map, flags,
3876                                                     allocated, newblock);
3877
3878         /* get_block() before submit the IO, split the extent */
3879         if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
3880                 ret = ext4_split_unwritten_extents(handle, inode, map,
3881                                                    path, flags);
3882                 if (ret <= 0)
3883                         goto out;
3884                 /*
3885                  * Flag the inode(non aio case) or end_io struct (aio case)
3886                  * that this IO needs to conversion to written when IO is
3887                  * completed
3888                  */
3889                 if (io)
3890                         ext4_set_io_unwritten_flag(inode, io);
3891                 else
3892                         ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3893                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3894                 if (ext4_should_dioread_nolock(inode))
3895                         map->m_flags |= EXT4_MAP_UNINIT;
3896                 goto out;
3897         }
3898         /* IO end_io complete, convert the filled extent to written */
3899         if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
3900                 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
3901                                                         path);
3902                 if (ret >= 0) {
3903                         ext4_update_inode_fsync_trans(handle, inode, 1);
3904                         err = check_eofblocks_fl(handle, inode, map->m_lblk,
3905                                                  path, map->m_len);
3906                 } else
3907                         err = ret;
3908                 map->m_flags |= EXT4_MAP_MAPPED;
3909                 if (allocated > map->m_len)
3910                         allocated = map->m_len;
3911                 map->m_len = allocated;
3912                 goto out2;
3913         }
3914         /* buffered IO case */
3915         /*
3916          * repeat fallocate creation request
3917          * we already have an unwritten extent
3918          */
3919         if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) {
3920                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3921                 goto map_out;
3922         }
3923
3924         /* buffered READ or buffered write_begin() lookup */
3925         if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3926                 /*
3927                  * We have blocks reserved already.  We
3928                  * return allocated blocks so that delalloc
3929                  * won't do block reservation for us.  But
3930                  * the buffer head will be unmapped so that
3931                  * a read from the block returns 0s.
3932                  */
3933                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3934                 goto out1;
3935         }
3936
3937         /* buffered write, writepage time, convert*/
3938         ret = ext4_ext_convert_to_initialized(handle, inode, map, path, flags);
3939         if (ret >= 0)
3940                 ext4_update_inode_fsync_trans(handle, inode, 1);
3941 out:
3942         if (ret <= 0) {
3943                 err = ret;
3944                 goto out2;
3945         } else
3946                 allocated = ret;
3947         map->m_flags |= EXT4_MAP_NEW;
3948         /*
3949          * if we allocated more blocks than requested
3950          * we need to make sure we unmap the extra block
3951          * allocated. The actual needed block will get
3952          * unmapped later when we find the buffer_head marked
3953          * new.
3954          */
3955         if (allocated > map->m_len) {
3956                 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
3957                                         newblock + map->m_len,
3958                                         allocated - map->m_len);
3959                 allocated = map->m_len;
3960         }
3961         map->m_len = allocated;
3962
3963         /*
3964          * If we have done fallocate with the offset that is already
3965          * delayed allocated, we would have block reservation
3966          * and quota reservation done in the delayed write path.
3967          * But fallocate would have already updated quota and block
3968          * count for this offset. So cancel these reservation
3969          */
3970         if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
3971                 unsigned int reserved_clusters;
3972                 reserved_clusters = get_reserved_cluster_alloc(inode,
3973                                 map->m_lblk, map->m_len);
3974                 if (reserved_clusters)
3975                         ext4_da_update_reserve_space(inode,
3976                                                      reserved_clusters,
3977                                                      0);
3978         }
3979
3980 map_out:
3981         map->m_flags |= EXT4_MAP_MAPPED;
3982         if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
3983                 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
3984                                          map->m_len);
3985                 if (err < 0)
3986                         goto out2;
3987         }
3988 out1:
3989         if (allocated > map->m_len)
3990                 allocated = map->m_len;
3991         ext4_ext_show_leaf(inode, path);
3992         map->m_pblk = newblock;
3993         map->m_len = allocated;
3994 out2:
3995         if (path) {
3996                 ext4_ext_drop_refs(path);
3997                 kfree(path);
3998         }
3999         return err ? err : allocated;
4000 }
4001
4002 /*
4003  * get_implied_cluster_alloc - check to see if the requested
4004  * allocation (in the map structure) overlaps with a cluster already
4005  * allocated in an extent.
4006  *      @sb     The filesystem superblock structure
4007  *      @map    The requested lblk->pblk mapping
4008  *      @ex     The extent structure which might contain an implied
4009  *                      cluster allocation
4010  *
4011  * This function is called by ext4_ext_map_blocks() after we failed to
4012  * find blocks that were already in the inode's extent tree.  Hence,
4013  * we know that the beginning of the requested region cannot overlap
4014  * the extent from the inode's extent tree.  There are three cases we
4015  * want to catch.  The first is this case:
4016  *
4017  *               |--- cluster # N--|
4018  *    |--- extent ---|  |---- requested region ---|
4019  *                      |==========|
4020  *
4021  * The second case that we need to test for is this one:
4022  *
4023  *   |--------- cluster # N ----------------|
4024  *         |--- requested region --|   |------- extent ----|
4025  *         |=======================|
4026  *
4027  * The third case is when the requested region lies between two extents
4028  * within the same cluster:
4029  *          |------------- cluster # N-------------|
4030  * |----- ex -----|                  |---- ex_right ----|
4031  *                  |------ requested region ------|
4032  *                  |================|
4033  *
4034  * In each of the above cases, we need to set the map->m_pblk and
4035  * map->m_len so it corresponds to the return the extent labelled as
4036  * "|====|" from cluster #N, since it is already in use for data in
4037  * cluster EXT4_B2C(sbi, map->m_lblk).  We will then return 1 to
4038  * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4039  * as a new "allocated" block region.  Otherwise, we will return 0 and
4040  * ext4_ext_map_blocks() will then allocate one or more new clusters
4041  * by calling ext4_mb_new_blocks().
4042  */
4043 static int get_implied_cluster_alloc(struct super_block *sb,
4044                                      struct ext4_map_blocks *map,
4045                                      struct ext4_extent *ex,
4046                                      struct ext4_ext_path *path)
4047 {
4048         struct ext4_sb_info *sbi = EXT4_SB(sb);
4049         ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4050         ext4_lblk_t ex_cluster_start, ex_cluster_end;
4051         ext4_lblk_t rr_cluster_start;
4052         ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4053         ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4054         unsigned short ee_len = ext4_ext_get_actual_len(ex);
4055
4056         /* The extent passed in that we are trying to match */
4057         ex_cluster_start = EXT4_B2C(sbi, ee_block);
4058         ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4059
4060         /* The requested region passed into ext4_map_blocks() */
4061         rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4062
4063         if ((rr_cluster_start == ex_cluster_end) ||
4064             (rr_cluster_start == ex_cluster_start)) {
4065                 if (rr_cluster_start == ex_cluster_end)
4066                         ee_start += ee_len - 1;
4067                 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4068                 map->m_len = min(map->m_len,
4069                                  (unsigned) sbi->s_cluster_ratio - c_offset);
4070                 /*
4071                  * Check for and handle this case:
4072                  *
4073                  *   |--------- cluster # N-------------|
4074                  *                     |------- extent ----|
4075                  *         |--- requested region ---|
4076                  *         |===========|
4077                  */
4078
4079                 if (map->m_lblk < ee_block)
4080                         map->m_len = min(map->m_len, ee_block - map->m_lblk);
4081
4082                 /*
4083                  * Check for the case where there is already another allocated
4084                  * block to the right of 'ex' but before the end of the cluster.
4085                  *
4086                  *          |------------- cluster # N-------------|
4087                  * |----- ex -----|                  |---- ex_right ----|
4088                  *                  |------ requested region ------|
4089                  *                  |================|
4090                  */
4091                 if (map->m_lblk > ee_block) {
4092                         ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4093                         map->m_len = min(map->m_len, next - map->m_lblk);
4094                 }
4095
4096                 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4097                 return 1;
4098         }
4099
4100         trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4101         return 0;
4102 }
4103
4104
4105 /*
4106  * Block allocation/map/preallocation routine for extents based files
4107  *
4108  *
4109  * Need to be called with
4110  * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4111  * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4112  *
4113  * return > 0, number of of blocks already mapped/allocated
4114  *          if create == 0 and these are pre-allocated blocks
4115  *              buffer head is unmapped
4116  *          otherwise blocks are mapped
4117  *
4118  * return = 0, if plain look up failed (blocks have not been allocated)
4119  *          buffer head is unmapped
4120  *
4121  * return < 0, error case.
4122  */
4123 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4124                         struct ext4_map_blocks *map, int flags)
4125 {
4126         struct ext4_ext_path *path = NULL;
4127         struct ext4_extent newex, *ex, *ex2;
4128         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4129         ext4_fsblk_t newblock = 0;
4130         int free_on_err = 0, err = 0, depth;
4131         unsigned int allocated = 0, offset = 0;
4132         unsigned int allocated_clusters = 0;
4133         struct ext4_allocation_request ar;
4134         ext4_io_end_t *io = ext4_inode_aio(inode);
4135         ext4_lblk_t cluster_offset;
4136         int set_unwritten = 0;
4137
4138         ext_debug("blocks %u/%u requested for inode %lu\n",
4139                   map->m_lblk, map->m_len, inode->i_ino);
4140         trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4141
4142         /* find extent for this block */
4143         path = ext4_ext_find_extent(inode, map->m_lblk, NULL, 0);
4144         if (IS_ERR(path)) {
4145                 err = PTR_ERR(path);
4146                 path = NULL;
4147                 goto out2;
4148         }
4149
4150         depth = ext_depth(inode);
4151
4152         /*
4153          * consistent leaf must not be empty;
4154          * this situation is possible, though, _during_ tree modification;
4155          * this is why assert can't be put in ext4_ext_find_extent()
4156          */
4157         if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4158                 EXT4_ERROR_INODE(inode, "bad extent address "
4159                                  "lblock: %lu, depth: %d pblock %lld",
4160                                  (unsigned long) map->m_lblk, depth,
4161                                  path[depth].p_block);
4162                 err = -EIO;
4163                 goto out2;
4164         }
4165
4166         ex = path[depth].p_ext;
4167         if (ex) {
4168                 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4169                 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4170                 unsigned short ee_len;
4171
4172                 /*
4173                  * Uninitialized extents are treated as holes, except that
4174                  * we split out initialized portions during a write.
4175                  */
4176                 ee_len = ext4_ext_get_actual_len(ex);
4177
4178                 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4179
4180                 /* if found extent covers block, simply return it */
4181                 if (in_range(map->m_lblk, ee_block, ee_len)) {
4182                         newblock = map->m_lblk - ee_block + ee_start;
4183                         /* number of remaining blocks in the extent */
4184                         allocated = ee_len - (map->m_lblk - ee_block);
4185                         ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
4186                                   ee_block, ee_len, newblock);
4187
4188                         if (!ext4_ext_is_uninitialized(ex))
4189                                 goto out;
4190
4191                         allocated = ext4_ext_handle_uninitialized_extents(
4192                                 handle, inode, map, path, flags,
4193                                 allocated, newblock);
4194                         goto out3;
4195                 }
4196         }
4197
4198         if ((sbi->s_cluster_ratio > 1) &&
4199             ext4_find_delalloc_cluster(inode, map->m_lblk))
4200                 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4201
4202         /*
4203          * requested block isn't allocated yet;
4204          * we couldn't try to create block if create flag is zero
4205          */
4206         if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4207                 /*
4208                  * put just found gap into cache to speed up
4209                  * subsequent requests
4210                  */
4211                 if ((flags & EXT4_GET_BLOCKS_NO_PUT_HOLE) == 0)
4212                         ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
4213                 goto out2;
4214         }
4215
4216         /*
4217          * Okay, we need to do block allocation.
4218          */
4219         map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
4220         newex.ee_block = cpu_to_le32(map->m_lblk);
4221         cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4222
4223         /*
4224          * If we are doing bigalloc, check to see if the extent returned
4225          * by ext4_ext_find_extent() implies a cluster we can use.
4226          */
4227         if (cluster_offset && ex &&
4228             get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4229                 ar.len = allocated = map->m_len;
4230                 newblock = map->m_pblk;
4231                 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4232                 goto got_allocated_blocks;
4233         }
4234
4235         /* find neighbour allocated blocks */
4236         ar.lleft = map->m_lblk;
4237         err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4238         if (err)
4239                 goto out2;
4240         ar.lright = map->m_lblk;
4241         ex2 = NULL;
4242         err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4243         if (err)
4244                 goto out2;
4245
4246         /* Check if the extent after searching to the right implies a
4247          * cluster we can use. */
4248         if ((sbi->s_cluster_ratio > 1) && ex2 &&
4249             get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4250                 ar.len = allocated = map->m_len;
4251                 newblock = map->m_pblk;
4252                 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4253                 goto got_allocated_blocks;
4254         }
4255
4256         /*
4257          * See if request is beyond maximum number of blocks we can have in
4258          * a single extent. For an initialized extent this limit is
4259          * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
4260          * EXT_UNINIT_MAX_LEN.
4261          */
4262         if (map->m_len > EXT_INIT_MAX_LEN &&
4263             !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4264                 map->m_len = EXT_INIT_MAX_LEN;
4265         else if (map->m_len > EXT_UNINIT_MAX_LEN &&
4266                  (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4267                 map->m_len = EXT_UNINIT_MAX_LEN;
4268
4269         /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4270         newex.ee_len = cpu_to_le16(map->m_len);
4271         err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4272         if (err)
4273                 allocated = ext4_ext_get_actual_len(&newex);
4274         else
4275                 allocated = map->m_len;
4276
4277         /* allocate new block */
4278         ar.inode = inode;
4279         ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4280         ar.logical = map->m_lblk;
4281         /*
4282          * We calculate the offset from the beginning of the cluster
4283          * for the logical block number, since when we allocate a
4284          * physical cluster, the physical block should start at the
4285          * same offset from the beginning of the cluster.  This is
4286          * needed so that future calls to get_implied_cluster_alloc()
4287          * work correctly.
4288          */
4289         offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4290         ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4291         ar.goal -= offset;
4292         ar.logical -= offset;
4293         if (S_ISREG(inode->i_mode))
4294                 ar.flags = EXT4_MB_HINT_DATA;
4295         else
4296                 /* disable in-core preallocation for non-regular files */
4297                 ar.flags = 0;
4298         if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4299                 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4300         newblock = ext4_mb_new_blocks(handle, &ar, &err);
4301         if (!newblock)
4302                 goto out2;
4303         ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4304                   ar.goal, newblock, allocated);
4305         free_on_err = 1;
4306         allocated_clusters = ar.len;
4307         ar.len = EXT4_C2B(sbi, ar.len) - offset;
4308         if (ar.len > allocated)
4309                 ar.len = allocated;
4310
4311 got_allocated_blocks:
4312         /* try to insert new extent into found leaf and return */
4313         ext4_ext_store_pblock(&newex, newblock + offset);
4314         newex.ee_len = cpu_to_le16(ar.len);
4315         /* Mark uninitialized */
4316         if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
4317                 ext4_ext_mark_uninitialized(&newex);
4318                 map->m_flags |= EXT4_MAP_UNWRITTEN;
4319                 /*
4320                  * io_end structure was created for every IO write to an
4321                  * uninitialized extent. To avoid unnecessary conversion,
4322                  * here we flag the IO that really needs the conversion.
4323                  * For non asycn direct IO case, flag the inode state
4324                  * that we need to perform conversion when IO is done.
4325                  */
4326                 if ((flags & EXT4_GET_BLOCKS_PRE_IO))
4327                         set_unwritten = 1;
4328                 if (ext4_should_dioread_nolock(inode))
4329                         map->m_flags |= EXT4_MAP_UNINIT;
4330         }
4331
4332         err = 0;
4333         if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4334                 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4335                                          path, ar.len);
4336         if (!err)
4337                 err = ext4_ext_insert_extent(handle, inode, path,
4338                                              &newex, flags);
4339
4340         if (!err && set_unwritten) {
4341                 if (io)
4342                         ext4_set_io_unwritten_flag(inode, io);
4343                 else
4344                         ext4_set_inode_state(inode,
4345                                              EXT4_STATE_DIO_UNWRITTEN);
4346         }
4347
4348         if (err && free_on_err) {
4349                 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4350                         EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4351                 /* free data blocks we just allocated */
4352                 /* not a good idea to call discard here directly,
4353                  * but otherwise we'd need to call it every free() */
4354                 ext4_discard_preallocations(inode);
4355                 ext4_free_blocks(handle, inode, NULL, newblock,
4356                                  EXT4_C2B(sbi, allocated_clusters), fb_flags);
4357                 goto out2;
4358         }
4359
4360         /* previous routine could use block we allocated */
4361         newblock = ext4_ext_pblock(&newex);
4362         allocated = ext4_ext_get_actual_len(&newex);
4363         if (allocated > map->m_len)
4364                 allocated = map->m_len;
4365         map->m_flags |= EXT4_MAP_NEW;
4366
4367         /*
4368          * Update reserved blocks/metadata blocks after successful
4369          * block allocation which had been deferred till now.
4370          */
4371         if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4372                 unsigned int reserved_clusters;
4373                 /*
4374                  * Check how many clusters we had reserved this allocated range
4375                  */
4376                 reserved_clusters = get_reserved_cluster_alloc(inode,
4377                                                 map->m_lblk, allocated);
4378                 if (map->m_flags & EXT4_MAP_FROM_CLUSTER) {
4379                         if (reserved_clusters) {
4380                                 /*
4381                                  * We have clusters reserved for this range.
4382                                  * But since we are not doing actual allocation
4383                                  * and are simply using blocks from previously
4384                                  * allocated cluster, we should release the
4385                                  * reservation and not claim quota.
4386                                  */
4387                                 ext4_da_update_reserve_space(inode,
4388                                                 reserved_clusters, 0);
4389                         }
4390                 } else {
4391                         BUG_ON(allocated_clusters < reserved_clusters);
4392                         if (reserved_clusters < allocated_clusters) {
4393                                 struct ext4_inode_info *ei = EXT4_I(inode);
4394                                 int reservation = allocated_clusters -
4395                                                   reserved_clusters;
4396                                 /*
4397                                  * It seems we claimed few clusters outside of
4398                                  * the range of this allocation. We should give
4399                                  * it back to the reservation pool. This can
4400                                  * happen in the following case:
4401                                  *
4402                                  * * Suppose s_cluster_ratio is 4 (i.e., each
4403                                  *   cluster has 4 blocks. Thus, the clusters
4404                                  *   are [0-3],[4-7],[8-11]...
4405                                  * * First comes delayed allocation write for
4406                                  *   logical blocks 10 & 11. Since there were no
4407                                  *   previous delayed allocated blocks in the
4408                                  *   range [8-11], we would reserve 1 cluster
4409                                  *   for this write.
4410                                  * * Next comes write for logical blocks 3 to 8.
4411                                  *   In this case, we will reserve 2 clusters
4412                                  *   (for [0-3] and [4-7]; and not for [8-11] as
4413                                  *   that range has a delayed allocated blocks.
4414                                  *   Thus total reserved clusters now becomes 3.
4415                                  * * Now, during the delayed allocation writeout
4416                                  *   time, we will first write blocks [3-8] and
4417                                  *   allocate 3 clusters for writing these
4418                                  *   blocks. Also, we would claim all these
4419                                  *   three clusters above.
4420                                  * * Now when we come here to writeout the
4421                                  *   blocks [10-11], we would expect to claim
4422                                  *   the reservation of 1 cluster we had made
4423                                  *   (and we would claim it since there are no
4424                                  *   more delayed allocated blocks in the range
4425                                  *   [8-11]. But our reserved cluster count had
4426                                  *   already gone to 0.
4427                                  *
4428                                  *   Thus, at the step 4 above when we determine
4429                                  *   that there are still some unwritten delayed
4430                                  *   allocated blocks outside of our current
4431                                  *   block range, we should increment the
4432                                  *   reserved clusters count so that when the
4433                                  *   remaining blocks finally gets written, we
4434                                  *   could claim them.
4435                                  */
4436                                 dquot_reserve_block(inode,
4437                                                 EXT4_C2B(sbi, reservation));
4438                                 spin_lock(&ei->i_block_reservation_lock);
4439                                 ei->i_reserved_data_blocks += reservation;
4440                                 spin_unlock(&ei->i_block_reservation_lock);
4441                         }
4442                         /*
4443                          * We will claim quota for all newly allocated blocks.
4444                          * We're updating the reserved space *after* the
4445                          * correction above so we do not accidentally free
4446                          * all the metadata reservation because we might
4447                          * actually need it later on.
4448                          */
4449                         ext4_da_update_reserve_space(inode, allocated_clusters,
4450                                                         1);
4451                 }
4452         }
4453
4454         /*
4455          * Cache the extent and update transaction to commit on fdatasync only
4456          * when it is _not_ an uninitialized extent.
4457          */
4458         if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)
4459                 ext4_update_inode_fsync_trans(handle, inode, 1);
4460         else
4461                 ext4_update_inode_fsync_trans(handle, inode, 0);
4462 out:
4463         if (allocated > map->m_len)
4464                 allocated = map->m_len;
4465         ext4_ext_show_leaf(inode, path);
4466         map->m_flags |= EXT4_MAP_MAPPED;
4467         map->m_pblk = newblock;
4468         map->m_len = allocated;
4469 out2:
4470         if (path) {
4471                 ext4_ext_drop_refs(path);
4472                 kfree(path);
4473         }
4474
4475 out3:
4476         trace_ext4_ext_map_blocks_exit(inode, flags, map,
4477                                        err ? err : allocated);
4478         ext4_es_lru_add(inode);
4479         return err ? err : allocated;
4480 }
4481
4482 void ext4_ext_truncate(handle_t *handle, struct inode *inode)
4483 {
4484         struct super_block *sb = inode->i_sb;
4485         ext4_lblk_t last_block;
4486         int err = 0;
4487
4488         /*
4489          * TODO: optimization is possible here.
4490          * Probably we need not scan at all,
4491          * because page truncation is enough.
4492          */
4493
4494         /* we have to know where to truncate from in crash case */
4495         EXT4_I(inode)->i_disksize = inode->i_size;
4496         ext4_mark_inode_dirty(handle, inode);
4497
4498         last_block = (inode->i_size + sb->s_blocksize - 1)
4499                         >> EXT4_BLOCK_SIZE_BITS(sb);
4500 retry:
4501         err = ext4_es_remove_extent(inode, last_block,
4502                                     EXT_MAX_BLOCKS - last_block);
4503         if (err == -ENOMEM) {
4504                 cond_resched();
4505                 congestion_wait(BLK_RW_ASYNC, HZ/50);
4506                 goto retry;
4507         }
4508         if (err) {
4509                 ext4_std_error(inode->i_sb, err);
4510                 return;
4511         }
4512         err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4513         ext4_std_error(inode->i_sb, err);
4514 }
4515
4516 static void ext4_falloc_update_inode(struct inode *inode,
4517                                 int mode, loff_t new_size, int update_ctime)
4518 {
4519         struct timespec now;
4520
4521         if (update_ctime) {
4522                 now = current_fs_time(inode->i_sb);
4523                 if (!timespec_equal(&inode->i_ctime, &now))
4524                         inode->i_ctime = now;
4525         }
4526         /*
4527          * Update only when preallocation was requested beyond
4528          * the file size.
4529          */
4530         if (!(mode & FALLOC_FL_KEEP_SIZE)) {
4531                 if (new_size > i_size_read(inode))
4532                         i_size_write(inode, new_size);
4533                 if (new_size > EXT4_I(inode)->i_disksize)
4534                         ext4_update_i_disksize(inode, new_size);
4535         } else {
4536                 /*
4537                  * Mark that we allocate beyond EOF so the subsequent truncate
4538                  * can proceed even if the new size is the same as i_size.
4539                  */
4540                 if (new_size > i_size_read(inode))
4541                         ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4542         }
4543
4544 }
4545
4546 /*
4547  * preallocate space for a file. This implements ext4's fallocate file
4548  * operation, which gets called from sys_fallocate system call.
4549  * For block-mapped files, posix_fallocate should fall back to the method
4550  * of writing zeroes to the required new blocks (the same behavior which is
4551  * expected for file systems which do not support fallocate() system call).
4552  */
4553 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4554 {
4555         struct inode *inode = file_inode(file);
4556         handle_t *handle;
4557         loff_t new_size;
4558         unsigned int max_blocks;
4559         int ret = 0;
4560         int ret2 = 0;
4561         int retries = 0;
4562         int flags;
4563         struct ext4_map_blocks map;
4564         unsigned int credits, blkbits = inode->i_blkbits;
4565
4566         /* Return error if mode is not supported */
4567         if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
4568                 return -EOPNOTSUPP;
4569
4570         if (mode & FALLOC_FL_PUNCH_HOLE)
4571                 return ext4_punch_hole(inode, offset, len);
4572
4573         ret = ext4_convert_inline_data(inode);
4574         if (ret)
4575                 return ret;
4576
4577         /*
4578          * currently supporting (pre)allocate mode for extent-based
4579          * files _only_
4580          */
4581         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4582                 return -EOPNOTSUPP;
4583
4584         trace_ext4_fallocate_enter(inode, offset, len, mode);
4585         map.m_lblk = offset >> blkbits;
4586         /*
4587          * We can't just convert len to max_blocks because
4588          * If blocksize = 4096 offset = 3072 and len = 2048
4589          */
4590         max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4591                 - map.m_lblk;
4592         /*
4593          * credits to insert 1 extent into extent tree
4594          */
4595         credits = ext4_chunk_trans_blocks(inode, max_blocks);
4596         mutex_lock(&inode->i_mutex);
4597         ret = inode_newsize_ok(inode, (len + offset));
4598         if (ret) {
4599                 mutex_unlock(&inode->i_mutex);
4600                 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4601                 return ret;
4602         }
4603         flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
4604         if (mode & FALLOC_FL_KEEP_SIZE)
4605                 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4606         /*
4607          * Don't normalize the request if it can fit in one extent so
4608          * that it doesn't get unnecessarily split into multiple
4609          * extents.
4610          */
4611         if (len <= EXT_UNINIT_MAX_LEN << blkbits)
4612                 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4613
4614 retry:
4615         while (ret >= 0 && ret < max_blocks) {
4616                 map.m_lblk = map.m_lblk + ret;
4617                 map.m_len = max_blocks = max_blocks - ret;
4618                 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4619                                             credits);
4620                 if (IS_ERR(handle)) {
4621                         ret = PTR_ERR(handle);
4622                         break;
4623                 }
4624                 ret = ext4_map_blocks(handle, inode, &map, flags);
4625                 if (ret <= 0) {
4626 #ifdef EXT4FS_DEBUG
4627                         ext4_warning(inode->i_sb,
4628                                      "inode #%lu: block %u: len %u: "
4629                                      "ext4_ext_map_blocks returned %d",
4630                                      inode->i_ino, map.m_lblk,
4631                                      map.m_len, ret);
4632 #endif
4633                         ext4_mark_inode_dirty(handle, inode);
4634                         ret2 = ext4_journal_stop(handle);
4635                         break;
4636                 }
4637                 if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
4638                                                 blkbits) >> blkbits))
4639                         new_size = offset + len;
4640                 else
4641                         new_size = ((loff_t) map.m_lblk + ret) << blkbits;
4642
4643                 ext4_falloc_update_inode(inode, mode, new_size,
4644                                          (map.m_flags & EXT4_MAP_NEW));
4645                 ext4_mark_inode_dirty(handle, inode);
4646                 if ((file->f_flags & O_SYNC) && ret >= max_blocks)
4647                         ext4_handle_sync(handle);
4648                 ret2 = ext4_journal_stop(handle);
4649                 if (ret2)
4650                         break;
4651         }
4652         if (ret == -ENOSPC &&
4653                         ext4_should_retry_alloc(inode->i_sb, &retries)) {
4654                 ret = 0;
4655                 goto retry;
4656         }
4657         mutex_unlock(&inode->i_mutex);
4658         trace_ext4_fallocate_exit(inode, offset, max_blocks,
4659                                 ret > 0 ? ret2 : ret);
4660         return ret > 0 ? ret2 : ret;
4661 }
4662
4663 /*
4664  * This function convert a range of blocks to written extents
4665  * The caller of this function will pass the start offset and the size.
4666  * all unwritten extents within this range will be converted to
4667  * written extents.
4668  *
4669  * This function is called from the direct IO end io call back
4670  * function, to convert the fallocated extents after IO is completed.
4671  * Returns 0 on success.
4672  */
4673 int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
4674                                    loff_t offset, ssize_t len)
4675 {
4676         unsigned int max_blocks;
4677         int ret = 0;
4678         int ret2 = 0;
4679         struct ext4_map_blocks map;
4680         unsigned int credits, blkbits = inode->i_blkbits;
4681
4682         map.m_lblk = offset >> blkbits;
4683         /*
4684          * We can't just convert len to max_blocks because
4685          * If blocksize = 4096 offset = 3072 and len = 2048
4686          */
4687         max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
4688                       map.m_lblk);
4689         /*
4690          * This is somewhat ugly but the idea is clear: When transaction is
4691          * reserved, everything goes into it. Otherwise we rather start several
4692          * smaller transactions for conversion of each extent separately.
4693          */
4694         if (handle) {
4695                 handle = ext4_journal_start_reserved(handle,
4696                                                      EXT4_HT_EXT_CONVERT);
4697                 if (IS_ERR(handle))
4698                         return PTR_ERR(handle);
4699                 credits = 0;
4700         } else {
4701                 /*
4702                  * credits to insert 1 extent into extent tree
4703                  */
4704                 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4705         }
4706         while (ret >= 0 && ret < max_blocks) {
4707                 map.m_lblk += ret;
4708                 map.m_len = (max_blocks -= ret);
4709                 if (credits) {
4710                         handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4711                                                     credits);
4712                         if (IS_ERR(handle)) {
4713                                 ret = PTR_ERR(handle);
4714                                 break;
4715                         }
4716                 }
4717                 ret = ext4_map_blocks(handle, inode, &map,
4718                                       EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4719                 if (ret <= 0)
4720                         ext4_warning(inode->i_sb,
4721                                      "inode #%lu: block %u: len %u: "
4722                                      "ext4_ext_map_blocks returned %d",
4723                                      inode->i_ino, map.m_lblk,
4724                                      map.m_len, ret);
4725                 ext4_mark_inode_dirty(handle, inode);
4726                 if (credits)
4727                         ret2 = ext4_journal_stop(handle);
4728                 if (ret <= 0 || ret2)
4729                         break;
4730         }
4731         if (!credits)
4732                 ret2 = ext4_journal_stop(handle);
4733         return ret > 0 ? ret2 : ret;
4734 }
4735
4736 /*
4737  * If newes is not existing extent (newes->ec_pblk equals zero) find
4738  * delayed extent at start of newes and update newes accordingly and
4739  * return start of the next delayed extent.
4740  *
4741  * If newes is existing extent (newes->ec_pblk is not equal zero)
4742  * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
4743  * extent found. Leave newes unmodified.
4744  */
4745 static int ext4_find_delayed_extent(struct inode *inode,
4746                                     struct extent_status *newes)
4747 {
4748         struct extent_status es;
4749         ext4_lblk_t block, next_del;
4750
4751         if (newes->es_pblk == 0) {
4752                 ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
4753                                 newes->es_lblk + newes->es_len - 1, &es);
4754
4755                 /*
4756                  * No extent in extent-tree contains block @newes->es_pblk,
4757                  * then the block may stay in 1)a hole or 2)delayed-extent.
4758                  */
4759                 if (es.es_len == 0)
4760                         /* A hole found. */
4761                         return 0;
4762
4763                 if (es.es_lblk > newes->es_lblk) {
4764                         /* A hole found. */
4765                         newes->es_len = min(es.es_lblk - newes->es_lblk,
4766                                             newes->es_len);
4767                         return 0;
4768                 }
4769
4770                 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
4771         }
4772
4773         block = newes->es_lblk + newes->es_len;
4774         ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
4775         if (es.es_len == 0)
4776                 next_del = EXT_MAX_BLOCKS;
4777         else
4778                 next_del = es.es_lblk;
4779
4780         return next_del;
4781 }
4782 /* fiemap flags we can handle specified here */
4783 #define EXT4_FIEMAP_FLAGS       (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
4784
4785 static int ext4_xattr_fiemap(struct inode *inode,
4786                                 struct fiemap_extent_info *fieinfo)
4787 {
4788         __u64 physical = 0;
4789         __u64 length;
4790         __u32 flags = FIEMAP_EXTENT_LAST;
4791         int blockbits = inode->i_sb->s_blocksize_bits;
4792         int error = 0;
4793
4794         /* in-inode? */
4795         if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4796                 struct ext4_iloc iloc;
4797                 int offset;     /* offset of xattr in inode */
4798
4799                 error = ext4_get_inode_loc(inode, &iloc);
4800                 if (error)
4801                         return error;
4802                 physical = (__u64)iloc.bh->b_blocknr << blockbits;
4803                 offset = EXT4_GOOD_OLD_INODE_SIZE +
4804                                 EXT4_I(inode)->i_extra_isize;
4805                 physical += offset;
4806                 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4807                 flags |= FIEMAP_EXTENT_DATA_INLINE;
4808                 brelse(iloc.bh);
4809         } else { /* external block */
4810                 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
4811                 length = inode->i_sb->s_blocksize;
4812         }
4813
4814         if (physical)
4815                 error = fiemap_fill_next_extent(fieinfo, 0, physical,
4816                                                 length, flags);
4817         return (error < 0 ? error : 0);
4818 }
4819
4820 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4821                 __u64 start, __u64 len)
4822 {
4823         ext4_lblk_t start_blk;
4824         int error = 0;
4825
4826         if (ext4_has_inline_data(inode)) {
4827                 int has_inline = 1;
4828
4829                 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline);
4830
4831                 if (has_inline)
4832                         return error;
4833         }
4834
4835         if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
4836                 error = ext4_ext_precache(inode);
4837                 if (error)
4838                         return error;
4839         }
4840
4841         /* fallback to generic here if not in extents fmt */
4842         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4843                 return generic_block_fiemap(inode, fieinfo, start, len,
4844                         ext4_get_block);
4845
4846         if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
4847                 return -EBADR;
4848
4849         if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4850                 error = ext4_xattr_fiemap(inode, fieinfo);
4851         } else {
4852                 ext4_lblk_t len_blks;
4853                 __u64 last_blk;
4854
4855                 start_blk = start >> inode->i_sb->s_blocksize_bits;
4856                 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
4857                 if (last_blk >= EXT_MAX_BLOCKS)
4858                         last_blk = EXT_MAX_BLOCKS-1;
4859                 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
4860
4861                 /*
4862                  * Walk the extent tree gathering extent information
4863                  * and pushing extents back to the user.
4864                  */
4865                 error = ext4_fill_fiemap_extents(inode, start_blk,
4866                                                  len_blks, fieinfo);
4867         }
4868         ext4_es_lru_add(inode);
4869         return error;
4870 }