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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/fs/ext4/indirect.c4 *5 * from6 *7 * linux/fs/ext4/inode.c8 *9 * Copyright (C) 1992, 1993, 1994, 199510 * Remy Card (card@masi.ibp.fr)11 * Laboratoire MASI - Institut Blaise Pascal12 * Universite Pierre et Marie Curie (Paris VI)13 *14 * from15 *16 * linux/fs/minix/inode.c17 *18 * Copyright (C) 1991, 1992 Linus Torvalds19 *20 * Goal-directed block allocation by Stephen Tweedie21 * (sct@redhat.com), 1993, 199822 */23 24#include "ext4_jbd2.h"25#include "truncate.h"26#include <linux/dax.h>27#include <linux/uio.h>28 29#include <trace/events/ext4.h>30 31typedef struct {32 __le32 *p;33 __le32 key;34 struct buffer_head *bh;35} Indirect;36 37static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)38{39 p->key = *(p->p = v);40 p->bh = bh;41}42 43/**44 * ext4_block_to_path - parse the block number into array of offsets45 * @inode: inode in question (we are only interested in its superblock)46 * @i_block: block number to be parsed47 * @offsets: array to store the offsets in48 * @boundary: set this non-zero if the referred-to block is likely to be49 * followed (on disk) by an indirect block.50 *51 * To store the locations of file's data ext4 uses a data structure common52 * for UNIX filesystems - tree of pointers anchored in the inode, with53 * data blocks at leaves and indirect blocks in intermediate nodes.54 * This function translates the block number into path in that tree -55 * return value is the path length and @offsets[n] is the offset of56 * pointer to (n+1)th node in the nth one. If @block is out of range57 * (negative or too large) warning is printed and zero returned.58 *59 * Note: function doesn't find node addresses, so no IO is needed. All60 * we need to know is the capacity of indirect blocks (taken from the61 * inode->i_sb).62 */63 64/*65 * Portability note: the last comparison (check that we fit into triple66 * indirect block) is spelled differently, because otherwise on an67 * architecture with 32-bit longs and 8Kb pages we might get into trouble68 * if our filesystem had 8Kb blocks. We might use long long, but that would69 * kill us on x86. Oh, well, at least the sign propagation does not matter -70 * i_block would have to be negative in the very beginning, so we would not71 * get there at all.72 */73 74static int ext4_block_to_path(struct inode *inode,75 ext4_lblk_t i_block,76 ext4_lblk_t offsets[4], int *boundary)77{78 int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);79 int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);80 const long direct_blocks = EXT4_NDIR_BLOCKS,81 indirect_blocks = ptrs,82 double_blocks = (1 << (ptrs_bits * 2));83 int n = 0;84 int final = 0;85 86 if (i_block < direct_blocks) {87 offsets[n++] = i_block;88 final = direct_blocks;89 } else if ((i_block -= direct_blocks) < indirect_blocks) {90 offsets[n++] = EXT4_IND_BLOCK;91 offsets[n++] = i_block;92 final = ptrs;93 } else if ((i_block -= indirect_blocks) < double_blocks) {94 offsets[n++] = EXT4_DIND_BLOCK;95 offsets[n++] = i_block >> ptrs_bits;96 offsets[n++] = i_block & (ptrs - 1);97 final = ptrs;98 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {99 offsets[n++] = EXT4_TIND_BLOCK;100 offsets[n++] = i_block >> (ptrs_bits * 2);101 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);102 offsets[n++] = i_block & (ptrs - 1);103 final = ptrs;104 } else {105 ext4_warning(inode->i_sb, "block %lu > max in inode %lu",106 i_block + direct_blocks +107 indirect_blocks + double_blocks, inode->i_ino);108 }109 if (boundary)110 *boundary = final - 1 - (i_block & (ptrs - 1));111 return n;112}113 114/**115 * ext4_get_branch - read the chain of indirect blocks leading to data116 * @inode: inode in question117 * @depth: depth of the chain (1 - direct pointer, etc.)118 * @offsets: offsets of pointers in inode/indirect blocks119 * @chain: place to store the result120 * @err: here we store the error value121 *122 * Function fills the array of triples <key, p, bh> and returns %NULL123 * if everything went OK or the pointer to the last filled triple124 * (incomplete one) otherwise. Upon the return chain[i].key contains125 * the number of (i+1)-th block in the chain (as it is stored in memory,126 * i.e. little-endian 32-bit), chain[i].p contains the address of that127 * number (it points into struct inode for i==0 and into the bh->b_data128 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect129 * block for i>0 and NULL for i==0. In other words, it holds the block130 * numbers of the chain, addresses they were taken from (and where we can131 * verify that chain did not change) and buffer_heads hosting these132 * numbers.133 *134 * Function stops when it stumbles upon zero pointer (absent block)135 * (pointer to last triple returned, *@err == 0)136 * or when it gets an IO error reading an indirect block137 * (ditto, *@err == -EIO)138 * or when it reads all @depth-1 indirect blocks successfully and finds139 * the whole chain, all way to the data (returns %NULL, *err == 0).140 *141 * Need to be called with142 * down_read(&EXT4_I(inode)->i_data_sem)143 */144static Indirect *ext4_get_branch(struct inode *inode, int depth,145 ext4_lblk_t *offsets,146 Indirect chain[4], int *err)147{148 struct super_block *sb = inode->i_sb;149 Indirect *p = chain;150 struct buffer_head *bh;151 unsigned int key;152 int ret = -EIO;153 154 *err = 0;155 /* i_data is not going away, no lock needed */156 add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);157 if (!p->key)158 goto no_block;159 while (--depth) {160 key = le32_to_cpu(p->key);161 if (key > ext4_blocks_count(EXT4_SB(sb)->s_es)) {162 /* the block was out of range */163 ret = -EFSCORRUPTED;164 goto failure;165 }166 bh = sb_getblk(sb, key);167 if (unlikely(!bh)) {168 ret = -ENOMEM;169 goto failure;170 }171 172 if (!bh_uptodate_or_lock(bh)) {173 if (ext4_read_bh(bh, 0, NULL) < 0) {174 put_bh(bh);175 goto failure;176 }177 /* validate block references */178 if (ext4_check_indirect_blockref(inode, bh)) {179 put_bh(bh);180 goto failure;181 }182 }183 184 add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);185 /* Reader: end */186 if (!p->key)187 goto no_block;188 }189 return NULL;190 191failure:192 *err = ret;193no_block:194 return p;195}196 197/**198 * ext4_find_near - find a place for allocation with sufficient locality199 * @inode: owner200 * @ind: descriptor of indirect block.201 *202 * This function returns the preferred place for block allocation.203 * It is used when heuristic for sequential allocation fails.204 * Rules are:205 * + if there is a block to the left of our position - allocate near it.206 * + if pointer will live in indirect block - allocate near that block.207 * + if pointer will live in inode - allocate in the same208 * cylinder group.209 *210 * In the latter case we colour the starting block by the callers PID to211 * prevent it from clashing with concurrent allocations for a different inode212 * in the same block group. The PID is used here so that functionally related213 * files will be close-by on-disk.214 *215 * Caller must make sure that @ind is valid and will stay that way.216 */217static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)218{219 struct ext4_inode_info *ei = EXT4_I(inode);220 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;221 __le32 *p;222 223 /* Try to find previous block */224 for (p = ind->p - 1; p >= start; p--) {225 if (*p)226 return le32_to_cpu(*p);227 }228 229 /* No such thing, so let's try location of indirect block */230 if (ind->bh)231 return ind->bh->b_blocknr;232 233 /*234 * It is going to be referred to from the inode itself? OK, just put it235 * into the same cylinder group then.236 */237 return ext4_inode_to_goal_block(inode);238}239 240/**241 * ext4_find_goal - find a preferred place for allocation.242 * @inode: owner243 * @block: block we want244 * @partial: pointer to the last triple within a chain245 *246 * Normally this function find the preferred place for block allocation,247 * returns it.248 * Because this is only used for non-extent files, we limit the block nr249 * to 32 bits.250 */251static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,252 Indirect *partial)253{254 ext4_fsblk_t goal;255 256 /*257 * XXX need to get goal block from mballoc's data structures258 */259 260 goal = ext4_find_near(inode, partial);261 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;262 return goal;263}264 265/**266 * ext4_blks_to_allocate - Look up the block map and count the number267 * of direct blocks need to be allocated for the given branch.268 *269 * @branch: chain of indirect blocks270 * @k: number of blocks need for indirect blocks271 * @blks: number of data blocks to be mapped.272 * @blocks_to_boundary: the offset in the indirect block273 *274 * return the total number of blocks to be allocate, including the275 * direct and indirect blocks.276 */277static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,278 int blocks_to_boundary)279{280 unsigned int count = 0;281 282 /*283 * Simple case, [t,d]Indirect block(s) has not allocated yet284 * then it's clear blocks on that path have not allocated285 */286 if (k > 0) {287 /* right now we don't handle cross boundary allocation */288 if (blks < blocks_to_boundary + 1)289 count += blks;290 else291 count += blocks_to_boundary + 1;292 return count;293 }294 295 count++;296 while (count < blks && count <= blocks_to_boundary &&297 le32_to_cpu(*(branch[0].p + count)) == 0) {298 count++;299 }300 return count;301}302 303/**304 * ext4_alloc_branch() - allocate and set up a chain of blocks305 * @handle: handle for this transaction306 * @ar: structure describing the allocation request307 * @indirect_blks: number of allocated indirect blocks308 * @offsets: offsets (in the blocks) to store the pointers to next.309 * @branch: place to store the chain in.310 *311 * This function allocates blocks, zeroes out all but the last one,312 * links them into chain and (if we are synchronous) writes them to disk.313 * In other words, it prepares a branch that can be spliced onto the314 * inode. It stores the information about that chain in the branch[], in315 * the same format as ext4_get_branch() would do. We are calling it after316 * we had read the existing part of chain and partial points to the last317 * triple of that (one with zero ->key). Upon the exit we have the same318 * picture as after the successful ext4_get_block(), except that in one319 * place chain is disconnected - *branch->p is still zero (we did not320 * set the last link), but branch->key contains the number that should321 * be placed into *branch->p to fill that gap.322 *323 * If allocation fails we free all blocks we've allocated (and forget324 * their buffer_heads) and return the error value the from failed325 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain326 * as described above and return 0.327 */328static int ext4_alloc_branch(handle_t *handle,329 struct ext4_allocation_request *ar,330 int indirect_blks, ext4_lblk_t *offsets,331 Indirect *branch)332{333 struct buffer_head * bh;334 ext4_fsblk_t b, new_blocks[4];335 __le32 *p;336 int i, j, err, len = 1;337 338 for (i = 0; i <= indirect_blks; i++) {339 if (i == indirect_blks) {340 new_blocks[i] = ext4_mb_new_blocks(handle, ar, &err);341 } else {342 ar->goal = new_blocks[i] = ext4_new_meta_blocks(handle,343 ar->inode, ar->goal,344 ar->flags & EXT4_MB_DELALLOC_RESERVED,345 NULL, &err);346 /* Simplify error cleanup... */347 branch[i+1].bh = NULL;348 }349 if (err) {350 i--;351 goto failed;352 }353 branch[i].key = cpu_to_le32(new_blocks[i]);354 if (i == 0)355 continue;356 357 bh = branch[i].bh = sb_getblk(ar->inode->i_sb, new_blocks[i-1]);358 if (unlikely(!bh)) {359 err = -ENOMEM;360 goto failed;361 }362 lock_buffer(bh);363 BUFFER_TRACE(bh, "call get_create_access");364 err = ext4_journal_get_create_access(handle, ar->inode->i_sb,365 bh, EXT4_JTR_NONE);366 if (err) {367 unlock_buffer(bh);368 goto failed;369 }370 371 memset(bh->b_data, 0, bh->b_size);372 p = branch[i].p = (__le32 *) bh->b_data + offsets[i];373 b = new_blocks[i];374 375 if (i == indirect_blks)376 len = ar->len;377 for (j = 0; j < len; j++)378 *p++ = cpu_to_le32(b++);379 380 BUFFER_TRACE(bh, "marking uptodate");381 set_buffer_uptodate(bh);382 unlock_buffer(bh);383 384 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");385 err = ext4_handle_dirty_metadata(handle, ar->inode, bh);386 if (err)387 goto failed;388 }389 return 0;390failed:391 if (i == indirect_blks) {392 /* Free data blocks */393 ext4_free_blocks(handle, ar->inode, NULL, new_blocks[i],394 ar->len, 0);395 i--;396 }397 for (; i >= 0; i--) {398 /*399 * We want to ext4_forget() only freshly allocated indirect400 * blocks. Buffer for new_blocks[i] is at branch[i+1].bh401 * (buffer at branch[0].bh is indirect block / inode already402 * existing before ext4_alloc_branch() was called). Also403 * because blocks are freshly allocated, we don't need to404 * revoke them which is why we don't set405 * EXT4_FREE_BLOCKS_METADATA.406 */407 ext4_free_blocks(handle, ar->inode, branch[i+1].bh,408 new_blocks[i], 1,409 branch[i+1].bh ? EXT4_FREE_BLOCKS_FORGET : 0);410 }411 return err;412}413 414/**415 * ext4_splice_branch() - splice the allocated branch onto inode.416 * @handle: handle for this transaction417 * @ar: structure describing the allocation request418 * @where: location of missing link419 * @num: number of indirect blocks we are adding420 *421 * This function fills the missing link and does all housekeeping needed in422 * inode (->i_blocks, etc.). In case of success we end up with the full423 * chain to new block and return 0.424 */425static int ext4_splice_branch(handle_t *handle,426 struct ext4_allocation_request *ar,427 Indirect *where, int num)428{429 int i;430 int err = 0;431 ext4_fsblk_t current_block;432 433 /*434 * If we're splicing into a [td]indirect block (as opposed to the435 * inode) then we need to get write access to the [td]indirect block436 * before the splice.437 */438 if (where->bh) {439 BUFFER_TRACE(where->bh, "get_write_access");440 err = ext4_journal_get_write_access(handle, ar->inode->i_sb,441 where->bh, EXT4_JTR_NONE);442 if (err)443 goto err_out;444 }445 /* That's it */446 447 *where->p = where->key;448 449 /*450 * Update the host buffer_head or inode to point to more just allocated451 * direct blocks blocks452 */453 if (num == 0 && ar->len > 1) {454 current_block = le32_to_cpu(where->key) + 1;455 for (i = 1; i < ar->len; i++)456 *(where->p + i) = cpu_to_le32(current_block++);457 }458 459 /* We are done with atomic stuff, now do the rest of housekeeping */460 /* had we spliced it onto indirect block? */461 if (where->bh) {462 /*463 * If we spliced it onto an indirect block, we haven't464 * altered the inode. Note however that if it is being spliced465 * onto an indirect block at the very end of the file (the466 * file is growing) then we *will* alter the inode to reflect467 * the new i_size. But that is not done here - it is done in468 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.469 */470 ext4_debug("splicing indirect only\n");471 BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");472 err = ext4_handle_dirty_metadata(handle, ar->inode, where->bh);473 if (err)474 goto err_out;475 } else {476 /*477 * OK, we spliced it into the inode itself on a direct block.478 */479 err = ext4_mark_inode_dirty(handle, ar->inode);480 if (unlikely(err))481 goto err_out;482 ext4_debug("splicing direct\n");483 }484 return err;485 486err_out:487 for (i = 1; i <= num; i++) {488 /*489 * branch[i].bh is newly allocated, so there is no490 * need to revoke the block, which is why we don't491 * need to set EXT4_FREE_BLOCKS_METADATA.492 */493 ext4_free_blocks(handle, ar->inode, where[i].bh, 0, 1,494 EXT4_FREE_BLOCKS_FORGET);495 }496 ext4_free_blocks(handle, ar->inode, NULL, le32_to_cpu(where[num].key),497 ar->len, 0);498 499 return err;500}501 502/*503 * The ext4_ind_map_blocks() function handles non-extents inodes504 * (i.e., using the traditional indirect/double-indirect i_blocks505 * scheme) for ext4_map_blocks().506 *507 * Allocation strategy is simple: if we have to allocate something, we will508 * have to go the whole way to leaf. So let's do it before attaching anything509 * to tree, set linkage between the newborn blocks, write them if sync is510 * required, recheck the path, free and repeat if check fails, otherwise511 * set the last missing link (that will protect us from any truncate-generated512 * removals - all blocks on the path are immune now) and possibly force the513 * write on the parent block.514 * That has a nice additional property: no special recovery from the failed515 * allocations is needed - we simply release blocks and do not touch anything516 * reachable from inode.517 *518 * `handle' can be NULL if create == 0.519 *520 * return > 0, # of blocks mapped or allocated.521 * return = 0, if plain lookup failed.522 * return < 0, error case.523 *524 * The ext4_ind_get_blocks() function should be called with525 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem526 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or527 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system528 * blocks.529 */530int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,531 struct ext4_map_blocks *map,532 int flags)533{534 struct ext4_allocation_request ar;535 int err = -EIO;536 ext4_lblk_t offsets[4];537 Indirect chain[4];538 Indirect *partial;539 int indirect_blks;540 int blocks_to_boundary = 0;541 int depth;542 int count = 0;543 ext4_fsblk_t first_block = 0;544 545 trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);546 ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));547 ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);548 depth = ext4_block_to_path(inode, map->m_lblk, offsets,549 &blocks_to_boundary);550 551 if (depth == 0)552 goto out;553 554 partial = ext4_get_branch(inode, depth, offsets, chain, &err);555 556 /* Simplest case - block found, no allocation needed */557 if (!partial) {558 first_block = le32_to_cpu(chain[depth - 1].key);559 count++;560 /*map more blocks*/561 while (count < map->m_len && count <= blocks_to_boundary) {562 ext4_fsblk_t blk;563 564 blk = le32_to_cpu(*(chain[depth-1].p + count));565 566 if (blk == first_block + count)567 count++;568 else569 break;570 }571 goto got_it;572 }573 574 /* Next simple case - plain lookup failed */575 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {576 unsigned epb = inode->i_sb->s_blocksize / sizeof(u32);577 int i;578 579 /*580 * Count number blocks in a subtree under 'partial'. At each581 * level we count number of complete empty subtrees beyond582 * current offset and then descend into the subtree only583 * partially beyond current offset.584 */585 count = 0;586 for (i = partial - chain + 1; i < depth; i++)587 count = count * epb + (epb - offsets[i] - 1);588 count++;589 /* Fill in size of a hole we found */590 map->m_pblk = 0;591 map->m_len = min_t(unsigned int, map->m_len, count);592 goto cleanup;593 }594 595 /* Failed read of indirect block */596 if (err == -EIO)597 goto cleanup;598 599 /*600 * Okay, we need to do block allocation.601 */602 if (ext4_has_feature_bigalloc(inode->i_sb)) {603 EXT4_ERROR_INODE(inode, "Can't allocate blocks for "604 "non-extent mapped inodes with bigalloc");605 err = -EFSCORRUPTED;606 goto out;607 }608 609 /* Set up for the direct block allocation */610 memset(&ar, 0, sizeof(ar));611 ar.inode = inode;612 ar.logical = map->m_lblk;613 if (S_ISREG(inode->i_mode))614 ar.flags = EXT4_MB_HINT_DATA;615 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)616 ar.flags |= EXT4_MB_DELALLOC_RESERVED;617 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)618 ar.flags |= EXT4_MB_USE_RESERVED;619 620 ar.goal = ext4_find_goal(inode, map->m_lblk, partial);621 622 /* the number of blocks need to allocate for [d,t]indirect blocks */623 indirect_blks = (chain + depth) - partial - 1;624 625 /*626 * Next look up the indirect map to count the totoal number of627 * direct blocks to allocate for this branch.628 */629 ar.len = ext4_blks_to_allocate(partial, indirect_blks,630 map->m_len, blocks_to_boundary);631 632 /*633 * Block out ext4_truncate while we alter the tree634 */635 err = ext4_alloc_branch(handle, &ar, indirect_blks,636 offsets + (partial - chain), partial);637 638 /*639 * The ext4_splice_branch call will free and forget any buffers640 * on the new chain if there is a failure, but that risks using641 * up transaction credits, especially for bitmaps where the642 * credits cannot be returned. Can we handle this somehow? We643 * may need to return -EAGAIN upwards in the worst case. --sct644 */645 if (!err)646 err = ext4_splice_branch(handle, &ar, partial, indirect_blks);647 if (err)648 goto cleanup;649 650 map->m_flags |= EXT4_MAP_NEW;651 652 ext4_update_inode_fsync_trans(handle, inode, 1);653 count = ar.len;654 655got_it:656 map->m_flags |= EXT4_MAP_MAPPED;657 map->m_pblk = le32_to_cpu(chain[depth-1].key);658 map->m_len = count;659 if (count > blocks_to_boundary)660 map->m_flags |= EXT4_MAP_BOUNDARY;661 err = count;662 /* Clean up and exit */663 partial = chain + depth - 1; /* the whole chain */664cleanup:665 while (partial > chain) {666 BUFFER_TRACE(partial->bh, "call brelse");667 brelse(partial->bh);668 partial--;669 }670out:671 trace_ext4_ind_map_blocks_exit(inode, flags, map, err);672 return err;673}674 675/*676 * Calculate number of indirect blocks touched by mapping @nrblocks logically677 * contiguous blocks678 */679int ext4_ind_trans_blocks(struct inode *inode, int nrblocks)680{681 /*682 * With N contiguous data blocks, we need at most683 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,684 * 2 dindirect blocks, and 1 tindirect block685 */686 return DIV_ROUND_UP(nrblocks, EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;687}688 689static int ext4_ind_trunc_restart_fn(handle_t *handle, struct inode *inode,690 struct buffer_head *bh, int *dropped)691{692 int err;693 694 if (bh) {695 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");696 err = ext4_handle_dirty_metadata(handle, inode, bh);697 if (unlikely(err))698 return err;699 }700 err = ext4_mark_inode_dirty(handle, inode);701 if (unlikely(err))702 return err;703 /*704 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this705 * moment, get_block can be called only for blocks inside i_size since706 * page cache has been already dropped and writes are blocked by707 * i_rwsem. So we can safely drop the i_data_sem here.708 */709 BUG_ON(EXT4_JOURNAL(inode) == NULL);710 ext4_discard_preallocations(inode);711 up_write(&EXT4_I(inode)->i_data_sem);712 *dropped = 1;713 return 0;714}715 716/*717 * Truncate transactions can be complex and absolutely huge. So we need to718 * be able to restart the transaction at a convenient checkpoint to make719 * sure we don't overflow the journal.720 *721 * Try to extend this transaction for the purposes of truncation. If722 * extend fails, we restart transaction.723 */724static int ext4_ind_truncate_ensure_credits(handle_t *handle,725 struct inode *inode,726 struct buffer_head *bh,727 int revoke_creds)728{729 int ret;730 int dropped = 0;731 732 ret = ext4_journal_ensure_credits_fn(handle, EXT4_RESERVE_TRANS_BLOCKS,733 ext4_blocks_for_truncate(inode), revoke_creds,734 ext4_ind_trunc_restart_fn(handle, inode, bh, &dropped));735 if (dropped)736 down_write(&EXT4_I(inode)->i_data_sem);737 if (ret <= 0)738 return ret;739 if (bh) {740 BUFFER_TRACE(bh, "retaking write access");741 ret = ext4_journal_get_write_access(handle, inode->i_sb, bh,742 EXT4_JTR_NONE);743 if (unlikely(ret))744 return ret;745 }746 return 0;747}748 749/*750 * Probably it should be a library function... search for first non-zero word751 * or memcmp with zero_page, whatever is better for particular architecture.752 * Linus?753 */754static inline int all_zeroes(__le32 *p, __le32 *q)755{756 while (p < q)757 if (*p++)758 return 0;759 return 1;760}761 762/**763 * ext4_find_shared - find the indirect blocks for partial truncation.764 * @inode: inode in question765 * @depth: depth of the affected branch766 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)767 * @chain: place to store the pointers to partial indirect blocks768 * @top: place to the (detached) top of branch769 *770 * This is a helper function used by ext4_truncate().771 *772 * When we do truncate() we may have to clean the ends of several773 * indirect blocks but leave the blocks themselves alive. Block is774 * partially truncated if some data below the new i_size is referred775 * from it (and it is on the path to the first completely truncated776 * data block, indeed). We have to free the top of that path along777 * with everything to the right of the path. Since no allocation778 * past the truncation point is possible until ext4_truncate()779 * finishes, we may safely do the latter, but top of branch may780 * require special attention - pageout below the truncation point781 * might try to populate it.782 *783 * We atomically detach the top of branch from the tree, store the784 * block number of its root in *@top, pointers to buffer_heads of785 * partially truncated blocks - in @chain[].bh and pointers to786 * their last elements that should not be removed - in787 * @chain[].p. Return value is the pointer to last filled element788 * of @chain.789 *790 * The work left to caller to do the actual freeing of subtrees:791 * a) free the subtree starting from *@top792 * b) free the subtrees whose roots are stored in793 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)794 * c) free the subtrees growing from the inode past the @chain[0].795 * (no partially truncated stuff there). */796 797static Indirect *ext4_find_shared(struct inode *inode, int depth,798 ext4_lblk_t offsets[4], Indirect chain[4],799 __le32 *top)800{801 Indirect *partial, *p;802 int k, err;803 804 *top = 0;805 /* Make k index the deepest non-null offset + 1 */806 for (k = depth; k > 1 && !offsets[k-1]; k--)807 ;808 partial = ext4_get_branch(inode, k, offsets, chain, &err);809 /* Writer: pointers */810 if (!partial)811 partial = chain + k-1;812 /*813 * If the branch acquired continuation since we've looked at it -814 * fine, it should all survive and (new) top doesn't belong to us.815 */816 if (!partial->key && *partial->p)817 /* Writer: end */818 goto no_top;819 for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)820 ;821 /*822 * OK, we've found the last block that must survive. The rest of our823 * branch should be detached before unlocking. However, if that rest824 * of branch is all ours and does not grow immediately from the inode825 * it's easier to cheat and just decrement partial->p.826 */827 if (p == chain + k - 1 && p > chain) {828 p->p--;829 } else {830 *top = *p->p;831 /* Nope, don't do this in ext4. Must leave the tree intact */832#if 0833 *p->p = 0;834#endif835 }836 /* Writer: end */837 838 while (partial > p) {839 brelse(partial->bh);840 partial--;841 }842no_top:843 return partial;844}845 846/*847 * Zero a number of block pointers in either an inode or an indirect block.848 * If we restart the transaction we must again get write access to the849 * indirect block for further modification.850 *851 * We release `count' blocks on disk, but (last - first) may be greater852 * than `count' because there can be holes in there.853 *854 * Return 0 on success, 1 on invalid block range855 * and < 0 on fatal error.856 */857static int ext4_clear_blocks(handle_t *handle, struct inode *inode,858 struct buffer_head *bh,859 ext4_fsblk_t block_to_free,860 unsigned long count, __le32 *first,861 __le32 *last)862{863 __le32 *p;864 int flags = EXT4_FREE_BLOCKS_VALIDATED;865 int err;866 867 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||868 ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))869 flags |= EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_METADATA;870 else if (ext4_should_journal_data(inode))871 flags |= EXT4_FREE_BLOCKS_FORGET;872 873 if (!ext4_inode_block_valid(inode, block_to_free, count)) {874 EXT4_ERROR_INODE(inode, "attempt to clear invalid "875 "blocks %llu len %lu",876 (unsigned long long) block_to_free, count);877 return 1;878 }879 880 err = ext4_ind_truncate_ensure_credits(handle, inode, bh,881 ext4_free_data_revoke_credits(inode, count));882 if (err < 0)883 goto out_err;884 885 for (p = first; p < last; p++)886 *p = 0;887 888 ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags);889 return 0;890out_err:891 ext4_std_error(inode->i_sb, err);892 return err;893}894 895/**896 * ext4_free_data - free a list of data blocks897 * @handle: handle for this transaction898 * @inode: inode we are dealing with899 * @this_bh: indirect buffer_head which contains *@first and *@last900 * @first: array of block numbers901 * @last: points immediately past the end of array902 *903 * We are freeing all blocks referred from that array (numbers are stored as904 * little-endian 32-bit) and updating @inode->i_blocks appropriately.905 *906 * We accumulate contiguous runs of blocks to free. Conveniently, if these907 * blocks are contiguous then releasing them at one time will only affect one908 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't909 * actually use a lot of journal space.910 *911 * @this_bh will be %NULL if @first and @last point into the inode's direct912 * block pointers.913 */914static void ext4_free_data(handle_t *handle, struct inode *inode,915 struct buffer_head *this_bh,916 __le32 *first, __le32 *last)917{918 ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */919 unsigned long count = 0; /* Number of blocks in the run */920 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind921 corresponding to922 block_to_free */923 ext4_fsblk_t nr; /* Current block # */924 __le32 *p; /* Pointer into inode/ind925 for current block */926 int err = 0;927 928 if (this_bh) { /* For indirect block */929 BUFFER_TRACE(this_bh, "get_write_access");930 err = ext4_journal_get_write_access(handle, inode->i_sb,931 this_bh, EXT4_JTR_NONE);932 /* Important: if we can't update the indirect pointers933 * to the blocks, we can't free them. */934 if (err)935 return;936 }937 938 for (p = first; p < last; p++) {939 nr = le32_to_cpu(*p);940 if (nr) {941 /* accumulate blocks to free if they're contiguous */942 if (count == 0) {943 block_to_free = nr;944 block_to_free_p = p;945 count = 1;946 } else if (nr == block_to_free + count) {947 count++;948 } else {949 err = ext4_clear_blocks(handle, inode, this_bh,950 block_to_free, count,951 block_to_free_p, p);952 if (err)953 break;954 block_to_free = nr;955 block_to_free_p = p;956 count = 1;957 }958 }959 }960 961 if (!err && count > 0)962 err = ext4_clear_blocks(handle, inode, this_bh, block_to_free,963 count, block_to_free_p, p);964 if (err < 0)965 /* fatal error */966 return;967 968 if (this_bh) {969 BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");970 971 /*972 * The buffer head should have an attached journal head at this973 * point. However, if the data is corrupted and an indirect974 * block pointed to itself, it would have been detached when975 * the block was cleared. Check for this instead of OOPSing.976 */977 if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))978 ext4_handle_dirty_metadata(handle, inode, this_bh);979 else980 EXT4_ERROR_INODE(inode,981 "circular indirect block detected at "982 "block %llu",983 (unsigned long long) this_bh->b_blocknr);984 }985}986 987/**988 * ext4_free_branches - free an array of branches989 * @handle: JBD handle for this transaction990 * @inode: inode we are dealing with991 * @parent_bh: the buffer_head which contains *@first and *@last992 * @first: array of block numbers993 * @last: pointer immediately past the end of array994 * @depth: depth of the branches to free995 *996 * We are freeing all blocks referred from these branches (numbers are997 * stored as little-endian 32-bit) and updating @inode->i_blocks998 * appropriately.999 */1000static void ext4_free_branches(handle_t *handle, struct inode *inode,1001 struct buffer_head *parent_bh,1002 __le32 *first, __le32 *last, int depth)1003{1004 ext4_fsblk_t nr;1005 __le32 *p;1006 1007 if (ext4_handle_is_aborted(handle))1008 return;1009 1010 if (depth--) {1011 struct buffer_head *bh;1012 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);1013 p = last;1014 while (--p >= first) {1015 nr = le32_to_cpu(*p);1016 if (!nr)1017 continue; /* A hole */1018 1019 if (!ext4_inode_block_valid(inode, nr, 1)) {1020 EXT4_ERROR_INODE(inode,1021 "invalid indirect mapped "1022 "block %lu (level %d)",1023 (unsigned long) nr, depth);1024 break;1025 }1026 1027 /* Go read the buffer for the next level down */1028 bh = ext4_sb_bread(inode->i_sb, nr, 0);1029 1030 /*1031 * A read failure? Report error and clear slot1032 * (should be rare).1033 */1034 if (IS_ERR(bh)) {1035 ext4_error_inode_block(inode, nr, -PTR_ERR(bh),1036 "Read failure");1037 continue;1038 }1039 1040 /* This zaps the entire block. Bottom up. */1041 BUFFER_TRACE(bh, "free child branches");1042 ext4_free_branches(handle, inode, bh,1043 (__le32 *) bh->b_data,1044 (__le32 *) bh->b_data + addr_per_block,1045 depth);1046 brelse(bh);1047 1048 /*1049 * Everything below this pointer has been1050 * released. Now let this top-of-subtree go.1051 *1052 * We want the freeing of this indirect block to be1053 * atomic in the journal with the updating of the1054 * bitmap block which owns it. So make some room in1055 * the journal.1056 *1057 * We zero the parent pointer *after* freeing its1058 * pointee in the bitmaps, so if extend_transaction()1059 * for some reason fails to put the bitmap changes and1060 * the release into the same transaction, recovery1061 * will merely complain about releasing a free block,1062 * rather than leaking blocks.1063 */1064 if (ext4_handle_is_aborted(handle))1065 return;1066 if (ext4_ind_truncate_ensure_credits(handle, inode,1067 NULL,1068 ext4_free_metadata_revoke_credits(1069 inode->i_sb, 1)) < 0)1070 return;1071 1072 /*1073 * The forget flag here is critical because if1074 * we are journaling (and not doing data1075 * journaling), we have to make sure a revoke1076 * record is written to prevent the journal1077 * replay from overwriting the (former)1078 * indirect block if it gets reallocated as a1079 * data block. This must happen in the same1080 * transaction where the data blocks are1081 * actually freed.1082 */1083 ext4_free_blocks(handle, inode, NULL, nr, 1,1084 EXT4_FREE_BLOCKS_METADATA|1085 EXT4_FREE_BLOCKS_FORGET);1086 1087 if (parent_bh) {1088 /*1089 * The block which we have just freed is1090 * pointed to by an indirect block: journal it1091 */1092 BUFFER_TRACE(parent_bh, "get_write_access");1093 if (!ext4_journal_get_write_access(handle,1094 inode->i_sb, parent_bh,1095 EXT4_JTR_NONE)) {1096 *p = 0;1097 BUFFER_TRACE(parent_bh,1098 "call ext4_handle_dirty_metadata");1099 ext4_handle_dirty_metadata(handle,1100 inode,1101 parent_bh);1102 }1103 }1104 }1105 } else {1106 /* We have reached the bottom of the tree. */1107 BUFFER_TRACE(parent_bh, "free data blocks");1108 ext4_free_data(handle, inode, parent_bh, first, last);1109 }1110}1111 1112void ext4_ind_truncate(handle_t *handle, struct inode *inode)1113{1114 struct ext4_inode_info *ei = EXT4_I(inode);1115 __le32 *i_data = ei->i_data;1116 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);1117 ext4_lblk_t offsets[4];1118 Indirect chain[4];1119 Indirect *partial;1120 __le32 nr = 0;1121 int n = 0;1122 ext4_lblk_t last_block, max_block;1123 unsigned blocksize = inode->i_sb->s_blocksize;1124 1125 last_block = (inode->i_size + blocksize-1)1126 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);1127 max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)1128 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);1129 1130 if (last_block != max_block) {1131 n = ext4_block_to_path(inode, last_block, offsets, NULL);1132 if (n == 0)1133 return;1134 }1135 1136 ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);1137 1138 /*1139 * The orphan list entry will now protect us from any crash which1140 * occurs before the truncate completes, so it is now safe to propagate1141 * the new, shorter inode size (held for now in i_size) into the1142 * on-disk inode. We do this via i_disksize, which is the value which1143 * ext4 *really* writes onto the disk inode.1144 */1145 ei->i_disksize = inode->i_size;1146 1147 if (last_block == max_block) {1148 /*1149 * It is unnecessary to free any data blocks if last_block is1150 * equal to the indirect block limit.1151 */1152 return;1153 } else if (n == 1) { /* direct blocks */1154 ext4_free_data(handle, inode, NULL, i_data+offsets[0],1155 i_data + EXT4_NDIR_BLOCKS);1156 goto do_indirects;1157 }1158 1159 partial = ext4_find_shared(inode, n, offsets, chain, &nr);1160 /* Kill the top of shared branch (not detached) */1161 if (nr) {1162 if (partial == chain) {1163 /* Shared branch grows from the inode */1164 ext4_free_branches(handle, inode, NULL,1165 &nr, &nr+1, (chain+n-1) - partial);1166 *partial->p = 0;1167 /*1168 * We mark the inode dirty prior to restart,1169 * and prior to stop. No need for it here.1170 */1171 } else {1172 /* Shared branch grows from an indirect block */1173 BUFFER_TRACE(partial->bh, "get_write_access");1174 ext4_free_branches(handle, inode, partial->bh,1175 partial->p,1176 partial->p+1, (chain+n-1) - partial);1177 }1178 }1179 /* Clear the ends of indirect blocks on the shared branch */1180 while (partial > chain) {1181 ext4_free_branches(handle, inode, partial->bh, partial->p + 1,1182 (__le32*)partial->bh->b_data+addr_per_block,1183 (chain+n-1) - partial);1184 BUFFER_TRACE(partial->bh, "call brelse");1185 brelse(partial->bh);1186 partial--;1187 }1188do_indirects:1189 /* Kill the remaining (whole) subtrees */1190 switch (offsets[0]) {1191 default:1192 nr = i_data[EXT4_IND_BLOCK];1193 if (nr) {1194 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);1195 i_data[EXT4_IND_BLOCK] = 0;1196 }1197 fallthrough;1198 case EXT4_IND_BLOCK:1199 nr = i_data[EXT4_DIND_BLOCK];1200 if (nr) {1201 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);1202 i_data[EXT4_DIND_BLOCK] = 0;1203 }1204 fallthrough;1205 case EXT4_DIND_BLOCK:1206 nr = i_data[EXT4_TIND_BLOCK];1207 if (nr) {1208 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);1209 i_data[EXT4_TIND_BLOCK] = 0;1210 }1211 fallthrough;1212 case EXT4_TIND_BLOCK:1213 ;1214 }1215}1216 1217/**1218 * ext4_ind_remove_space - remove space from the range1219 * @handle: JBD handle for this transaction1220 * @inode: inode we are dealing with1221 * @start: First block to remove1222 * @end: One block after the last block to remove (exclusive)1223 *1224 * Free the blocks in the defined range (end is exclusive endpoint of1225 * range). This is used by ext4_punch_hole().1226 */1227int ext4_ind_remove_space(handle_t *handle, struct inode *inode,1228 ext4_lblk_t start, ext4_lblk_t end)1229{1230 struct ext4_inode_info *ei = EXT4_I(inode);1231 __le32 *i_data = ei->i_data;1232 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);1233 ext4_lblk_t offsets[4], offsets2[4];1234 Indirect chain[4], chain2[4];1235 Indirect *partial, *partial2;1236 Indirect *p = NULL, *p2 = NULL;1237 ext4_lblk_t max_block;1238 __le32 nr = 0, nr2 = 0;1239 int n = 0, n2 = 0;1240 unsigned blocksize = inode->i_sb->s_blocksize;1241 1242 max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)1243 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);1244 if (end >= max_block)1245 end = max_block;1246 if ((start >= end) || (start > max_block))1247 return 0;1248 1249 n = ext4_block_to_path(inode, start, offsets, NULL);1250 n2 = ext4_block_to_path(inode, end, offsets2, NULL);1251 1252 BUG_ON(n > n2);1253 1254 if ((n == 1) && (n == n2)) {1255 /* We're punching only within direct block range */1256 ext4_free_data(handle, inode, NULL, i_data + offsets[0],1257 i_data + offsets2[0]);1258 return 0;1259 } else if (n2 > n) {1260 /*1261 * Start and end are on a different levels so we're going to1262 * free partial block at start, and partial block at end of1263 * the range. If there are some levels in between then1264 * do_indirects label will take care of that.1265 */1266 1267 if (n == 1) {1268 /*1269 * Start is at the direct block level, free1270 * everything to the end of the level.1271 */1272 ext4_free_data(handle, inode, NULL, i_data + offsets[0],1273 i_data + EXT4_NDIR_BLOCKS);1274 goto end_range;1275 }1276 1277 1278 partial = p = ext4_find_shared(inode, n, offsets, chain, &nr);1279 if (nr) {1280 if (partial == chain) {1281 /* Shared branch grows from the inode */1282 ext4_free_branches(handle, inode, NULL,1283 &nr, &nr+1, (chain+n-1) - partial);1284 *partial->p = 0;1285 } else {1286 /* Shared branch grows from an indirect block */1287 BUFFER_TRACE(partial->bh, "get_write_access");1288 ext4_free_branches(handle, inode, partial->bh,1289 partial->p,1290 partial->p+1, (chain+n-1) - partial);1291 }1292 }1293 1294 /*1295 * Clear the ends of indirect blocks on the shared branch1296 * at the start of the range1297 */1298 while (partial > chain) {1299 ext4_free_branches(handle, inode, partial->bh,1300 partial->p + 1,1301 (__le32 *)partial->bh->b_data+addr_per_block,1302 (chain+n-1) - partial);1303 partial--;1304 }1305 1306end_range:1307 partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);1308 if (nr2) {1309 if (partial2 == chain2) {1310 /*1311 * Remember, end is exclusive so here we're at1312 * the start of the next level we're not going1313 * to free. Everything was covered by the start1314 * of the range.1315 */1316 goto do_indirects;1317 }1318 } else {1319 /*1320 * ext4_find_shared returns Indirect structure which1321 * points to the last element which should not be1322 * removed by truncate. But this is end of the range1323 * in punch_hole so we need to point to the next element1324 */1325 partial2->p++;1326 }1327 1328 /*1329 * Clear the ends of indirect blocks on the shared branch1330 * at the end of the range1331 */1332 while (partial2 > chain2) {1333 ext4_free_branches(handle, inode, partial2->bh,1334 (__le32 *)partial2->bh->b_data,1335 partial2->p,1336 (chain2+n2-1) - partial2);1337 partial2--;1338 }1339 goto do_indirects;1340 }1341 1342 /* Punch happened within the same level (n == n2) */1343 partial = p = ext4_find_shared(inode, n, offsets, chain, &nr);1344 partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);1345 1346 /* Free top, but only if partial2 isn't its subtree. */1347 if (nr) {1348 int level = min(partial - chain, partial2 - chain2);1349 int i;1350 int subtree = 1;1351 1352 for (i = 0; i <= level; i++) {1353 if (offsets[i] != offsets2[i]) {1354 subtree = 0;1355 break;1356 }1357 }1358 1359 if (!subtree) {1360 if (partial == chain) {1361 /* Shared branch grows from the inode */1362 ext4_free_branches(handle, inode, NULL,1363 &nr, &nr+1,1364 (chain+n-1) - partial);1365 *partial->p = 0;1366 } else {1367 /* Shared branch grows from an indirect block */1368 BUFFER_TRACE(partial->bh, "get_write_access");1369 ext4_free_branches(handle, inode, partial->bh,1370 partial->p,1371 partial->p+1,1372 (chain+n-1) - partial);1373 }1374 }1375 }1376 1377 if (!nr2) {1378 /*1379 * ext4_find_shared returns Indirect structure which1380 * points to the last element which should not be1381 * removed by truncate. But this is end of the range1382 * in punch_hole so we need to point to the next element1383 */1384 partial2->p++;1385 }1386 1387 while (partial > chain || partial2 > chain2) {1388 int depth = (chain+n-1) - partial;1389 int depth2 = (chain2+n2-1) - partial2;1390 1391 if (partial > chain && partial2 > chain2 &&1392 partial->bh->b_blocknr == partial2->bh->b_blocknr) {1393 /*1394 * We've converged on the same block. Clear the range,1395 * then we're done.1396 */1397 ext4_free_branches(handle, inode, partial->bh,1398 partial->p + 1,1399 partial2->p,1400 (chain+n-1) - partial);1401 goto cleanup;1402 }1403 1404 /*1405 * The start and end partial branches may not be at the same1406 * level even though the punch happened within one level. So, we1407 * give them a chance to arrive at the same level, then walk1408 * them in step with each other until we converge on the same1409 * block.1410 */1411 if (partial > chain && depth <= depth2) {1412 ext4_free_branches(handle, inode, partial->bh,1413 partial->p + 1,1414 (__le32 *)partial->bh->b_data+addr_per_block,1415 (chain+n-1) - partial);1416 partial--;1417 }1418 if (partial2 > chain2 && depth2 <= depth) {1419 ext4_free_branches(handle, inode, partial2->bh,1420 (__le32 *)partial2->bh->b_data,1421 partial2->p,1422 (chain2+n2-1) - partial2);1423 partial2--;1424 }1425 }1426 1427cleanup:1428 while (p && p > chain) {1429 BUFFER_TRACE(p->bh, "call brelse");1430 brelse(p->bh);1431 p--;1432 }1433 while (p2 && p2 > chain2) {1434 BUFFER_TRACE(p2->bh, "call brelse");1435 brelse(p2->bh);1436 p2--;1437 }1438 return 0;1439 1440do_indirects:1441 /* Kill the remaining (whole) subtrees */1442 switch (offsets[0]) {1443 default:1444 if (++n >= n2)1445 break;1446 nr = i_data[EXT4_IND_BLOCK];1447 if (nr) {1448 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);1449 i_data[EXT4_IND_BLOCK] = 0;1450 }1451 fallthrough;1452 case EXT4_IND_BLOCK:1453 if (++n >= n2)1454 break;1455 nr = i_data[EXT4_DIND_BLOCK];1456 if (nr) {1457 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);1458 i_data[EXT4_DIND_BLOCK] = 0;1459 }1460 fallthrough;1461 case EXT4_DIND_BLOCK:1462 if (++n >= n2)1463 break;1464 nr = i_data[EXT4_TIND_BLOCK];1465 if (nr) {1466 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);1467 i_data[EXT4_TIND_BLOCK] = 0;1468 }1469 fallthrough;1470 case EXT4_TIND_BLOCK:1471 ;1472 }1473 goto cleanup;1474}1475