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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.4 */5 6#include <linux/init.h>7#include <linux/buffer_head.h>8#include <linux/mpage.h>9#include <linux/bio.h>10#include <linux/blkdev.h>11#include <linux/time.h>12#include <linux/writeback.h>13#include <linux/uio.h>14#include <linux/random.h>15#include <linux/iversion.h>16 17#include "exfat_raw.h"18#include "exfat_fs.h"19 20int __exfat_write_inode(struct inode *inode, int sync)21{22 unsigned long long on_disk_size;23 struct exfat_dentry *ep, *ep2;24 struct exfat_entry_set_cache es;25 struct super_block *sb = inode->i_sb;26 struct exfat_sb_info *sbi = EXFAT_SB(sb);27 struct exfat_inode_info *ei = EXFAT_I(inode);28 bool is_dir = (ei->type == TYPE_DIR) ? true : false;29 struct timespec64 ts;30 31 if (inode->i_ino == EXFAT_ROOT_INO)32 return 0;33 34 /*35 * If the inode is already unlinked, there is no need for updating it.36 */37 if (ei->dir.dir == DIR_DELETED)38 return 0;39 40 if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1)41 return 0;42 43 exfat_set_volume_dirty(sb);44 45 /* get the directory entry of given file or directory */46 if (exfat_get_dentry_set(&es, sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES))47 return -EIO;48 ep = exfat_get_dentry_cached(&es, ES_IDX_FILE);49 ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM);50 51 ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));52 53 /* set FILE_INFO structure using the acquired struct exfat_dentry */54 exfat_set_entry_time(sbi, &ei->i_crtime,55 &ep->dentry.file.create_tz,56 &ep->dentry.file.create_time,57 &ep->dentry.file.create_date,58 &ep->dentry.file.create_time_cs);59 ts = inode_get_mtime(inode);60 exfat_set_entry_time(sbi, &ts,61 &ep->dentry.file.modify_tz,62 &ep->dentry.file.modify_time,63 &ep->dentry.file.modify_date,64 &ep->dentry.file.modify_time_cs);65 ts = inode_get_atime(inode);66 exfat_set_entry_time(sbi, &ts,67 &ep->dentry.file.access_tz,68 &ep->dentry.file.access_time,69 &ep->dentry.file.access_date,70 NULL);71 72 /* File size should be zero if there is no cluster allocated */73 on_disk_size = i_size_read(inode);74 75 if (ei->start_clu == EXFAT_EOF_CLUSTER)76 on_disk_size = 0;77 78 ep2->dentry.stream.size = cpu_to_le64(on_disk_size);79 /*80 * mmap write does not use exfat_write_end(), valid_size may be81 * extended to the sector-aligned length in exfat_get_block().82 * So we need to fixup valid_size to the writren length.83 */84 if (on_disk_size < ei->valid_size)85 ep2->dentry.stream.valid_size = ep2->dentry.stream.size;86 else87 ep2->dentry.stream.valid_size = cpu_to_le64(ei->valid_size);88 89 if (on_disk_size) {90 ep2->dentry.stream.flags = ei->flags;91 ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu);92 } else {93 ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;94 ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;95 }96 97 exfat_update_dir_chksum(&es);98 return exfat_put_dentry_set(&es, sync);99}100 101int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)102{103 int ret;104 105 if (unlikely(exfat_forced_shutdown(inode->i_sb)))106 return -EIO;107 108 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);109 ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);110 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);111 112 return ret;113}114 115void exfat_sync_inode(struct inode *inode)116{117 lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock);118 __exfat_write_inode(inode, 1);119}120 121/*122 * Input: inode, (logical) clu_offset, target allocation area123 * Output: errcode, cluster number124 * *clu = (~0), if it's unable to allocate a new cluster125 */126static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,127 unsigned int *clu, int create)128{129 int ret;130 unsigned int last_clu;131 struct exfat_chain new_clu;132 struct super_block *sb = inode->i_sb;133 struct exfat_sb_info *sbi = EXFAT_SB(sb);134 struct exfat_inode_info *ei = EXFAT_I(inode);135 unsigned int local_clu_offset = clu_offset;136 unsigned int num_to_be_allocated = 0, num_clusters;137 138 num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);139 140 if (clu_offset >= num_clusters)141 num_to_be_allocated = clu_offset - num_clusters + 1;142 143 if (!create && (num_to_be_allocated > 0)) {144 *clu = EXFAT_EOF_CLUSTER;145 return 0;146 }147 148 *clu = last_clu = ei->start_clu;149 150 if (ei->flags == ALLOC_NO_FAT_CHAIN) {151 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {152 last_clu += clu_offset - 1;153 154 if (clu_offset == num_clusters)155 *clu = EXFAT_EOF_CLUSTER;156 else157 *clu += clu_offset;158 }159 } else if (ei->type == TYPE_FILE) {160 unsigned int fclus = 0;161 int err = exfat_get_cluster(inode, clu_offset,162 &fclus, clu, &last_clu, 1);163 if (err)164 return -EIO;165 166 clu_offset -= fclus;167 } else {168 /* hint information */169 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&170 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {171 clu_offset -= ei->hint_bmap.off;172 /* hint_bmap.clu should be valid */173 WARN_ON(ei->hint_bmap.clu < 2);174 *clu = ei->hint_bmap.clu;175 }176 177 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {178 last_clu = *clu;179 if (exfat_get_next_cluster(sb, clu))180 return -EIO;181 clu_offset--;182 }183 }184 185 if (*clu == EXFAT_EOF_CLUSTER) {186 exfat_set_volume_dirty(sb);187 188 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?189 EXFAT_EOF_CLUSTER : last_clu + 1;190 new_clu.size = 0;191 new_clu.flags = ei->flags;192 193 /* allocate a cluster */194 if (num_to_be_allocated < 1) {195 /* Broken FAT (i_sze > allocated FAT) */196 exfat_fs_error(sb, "broken FAT chain.");197 return -EIO;198 }199 200 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu,201 inode_needs_sync(inode));202 if (ret)203 return ret;204 205 if (new_clu.dir == EXFAT_EOF_CLUSTER ||206 new_clu.dir == EXFAT_FREE_CLUSTER) {207 exfat_fs_error(sb,208 "bogus cluster new allocated (last_clu : %u, new_clu : %u)",209 last_clu, new_clu.dir);210 return -EIO;211 }212 213 /* append to the FAT chain */214 if (last_clu == EXFAT_EOF_CLUSTER) {215 if (new_clu.flags == ALLOC_FAT_CHAIN)216 ei->flags = ALLOC_FAT_CHAIN;217 ei->start_clu = new_clu.dir;218 } else {219 if (new_clu.flags != ei->flags) {220 /* no-fat-chain bit is disabled,221 * so fat-chain should be synced with222 * alloc-bitmap223 */224 exfat_chain_cont_cluster(sb, ei->start_clu,225 num_clusters);226 ei->flags = ALLOC_FAT_CHAIN;227 }228 if (new_clu.flags == ALLOC_FAT_CHAIN)229 if (exfat_ent_set(sb, last_clu, new_clu.dir))230 return -EIO;231 }232 233 num_clusters += num_to_be_allocated;234 *clu = new_clu.dir;235 236 inode->i_blocks += EXFAT_CLU_TO_B(num_to_be_allocated, sbi) >> 9;237 238 /*239 * Move *clu pointer along FAT chains (hole care) because the240 * caller of this function expect *clu to be the last cluster.241 * This only works when num_to_be_allocated >= 2,242 * *clu = (the first cluster of the allocated chain) =>243 * (the last cluster of ...)244 */245 if (ei->flags == ALLOC_NO_FAT_CHAIN) {246 *clu += num_to_be_allocated - 1;247 } else {248 while (num_to_be_allocated > 1) {249 if (exfat_get_next_cluster(sb, clu))250 return -EIO;251 num_to_be_allocated--;252 }253 }254 255 }256 257 /* hint information */258 ei->hint_bmap.off = local_clu_offset;259 ei->hint_bmap.clu = *clu;260 261 return 0;262}263 264static int exfat_get_block(struct inode *inode, sector_t iblock,265 struct buffer_head *bh_result, int create)266{267 struct exfat_inode_info *ei = EXFAT_I(inode);268 struct super_block *sb = inode->i_sb;269 struct exfat_sb_info *sbi = EXFAT_SB(sb);270 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;271 int err = 0;272 unsigned long mapped_blocks = 0;273 unsigned int cluster, sec_offset;274 sector_t last_block;275 sector_t phys = 0;276 sector_t valid_blks;277 278 mutex_lock(&sbi->s_lock);279 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb);280 if (iblock >= last_block && !create)281 goto done;282 283 /* Is this block already allocated? */284 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits,285 &cluster, create);286 if (err) {287 if (err != -ENOSPC)288 exfat_fs_error_ratelimit(sb,289 "failed to bmap (inode : %p iblock : %llu, err : %d)",290 inode, (unsigned long long)iblock, err);291 goto unlock_ret;292 }293 294 if (cluster == EXFAT_EOF_CLUSTER)295 goto done;296 297 /* sector offset in cluster */298 sec_offset = iblock & (sbi->sect_per_clus - 1);299 300 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset;301 mapped_blocks = sbi->sect_per_clus - sec_offset;302 max_blocks = min(mapped_blocks, max_blocks);303 304 map_bh(bh_result, sb, phys);305 if (buffer_delay(bh_result))306 clear_buffer_delay(bh_result);307 308 if (create) {309 valid_blks = EXFAT_B_TO_BLK_ROUND_UP(ei->valid_size, sb);310 311 if (iblock + max_blocks < valid_blks) {312 /* The range has been written, map it */313 goto done;314 } else if (iblock < valid_blks) {315 /*316 * The range has been partially written,317 * map the written part.318 */319 max_blocks = valid_blks - iblock;320 goto done;321 }322 323 /* The area has not been written, map and mark as new. */324 set_buffer_new(bh_result);325 326 ei->valid_size = EXFAT_BLK_TO_B(iblock + max_blocks, sb);327 mark_inode_dirty(inode);328 } else {329 valid_blks = EXFAT_B_TO_BLK(ei->valid_size, sb);330 331 if (iblock + max_blocks < valid_blks) {332 /* The range has been written, map it */333 goto done;334 } else if (iblock < valid_blks) {335 /*336 * The area has been partially written,337 * map the written part.338 */339 max_blocks = valid_blks - iblock;340 goto done;341 } else if (iblock == valid_blks &&342 (ei->valid_size & (sb->s_blocksize - 1))) {343 /*344 * The block has been partially written,345 * zero the unwritten part and map the block.346 */347 loff_t size, off, pos;348 349 max_blocks = 1;350 351 /*352 * For direct read, the unwritten part will be zeroed in353 * exfat_direct_IO()354 */355 if (!bh_result->b_folio)356 goto done;357 358 pos = EXFAT_BLK_TO_B(iblock, sb);359 size = ei->valid_size - pos;360 off = pos & (PAGE_SIZE - 1);361 362 folio_set_bh(bh_result, bh_result->b_folio, off);363 err = bh_read(bh_result, 0);364 if (err < 0)365 goto unlock_ret;366 367 folio_zero_segment(bh_result->b_folio, off + size,368 off + sb->s_blocksize);369 } else {370 /*371 * The range has not been written, clear the mapped flag372 * to only zero the cache and do not read from disk.373 */374 clear_buffer_mapped(bh_result);375 }376 }377done:378 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);379unlock_ret:380 mutex_unlock(&sbi->s_lock);381 return err;382}383 384static int exfat_read_folio(struct file *file, struct folio *folio)385{386 return mpage_read_folio(folio, exfat_get_block);387}388 389static void exfat_readahead(struct readahead_control *rac)390{391 struct address_space *mapping = rac->mapping;392 struct inode *inode = mapping->host;393 struct exfat_inode_info *ei = EXFAT_I(inode);394 loff_t pos = readahead_pos(rac);395 396 /* Range cross valid_size, read it page by page. */397 if (ei->valid_size < i_size_read(inode) &&398 pos <= ei->valid_size &&399 ei->valid_size < pos + readahead_length(rac))400 return;401 402 mpage_readahead(rac, exfat_get_block);403}404 405static int exfat_writepages(struct address_space *mapping,406 struct writeback_control *wbc)407{408 if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))409 return -EIO;410 411 return mpage_writepages(mapping, wbc, exfat_get_block);412}413 414static void exfat_write_failed(struct address_space *mapping, loff_t to)415{416 struct inode *inode = mapping->host;417 418 if (to > i_size_read(inode)) {419 truncate_pagecache(inode, i_size_read(inode));420 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));421 exfat_truncate(inode);422 }423}424 425static int exfat_write_begin(struct file *file, struct address_space *mapping,426 loff_t pos, unsigned int len,427 struct folio **foliop, void **fsdata)428{429 int ret;430 431 if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))432 return -EIO;433 434 ret = block_write_begin(mapping, pos, len, foliop, exfat_get_block);435 436 if (ret < 0)437 exfat_write_failed(mapping, pos+len);438 439 return ret;440}441 442static int exfat_write_end(struct file *file, struct address_space *mapping,443 loff_t pos, unsigned int len, unsigned int copied,444 struct folio *folio, void *fsdata)445{446 struct inode *inode = mapping->host;447 struct exfat_inode_info *ei = EXFAT_I(inode);448 int err;449 450 err = generic_write_end(file, mapping, pos, len, copied, folio, fsdata);451 if (err < len)452 exfat_write_failed(mapping, pos+len);453 454 if (!(err < 0) && pos + err > ei->valid_size) {455 ei->valid_size = pos + err;456 mark_inode_dirty(inode);457 }458 459 if (!(err < 0) && !(ei->attr & EXFAT_ATTR_ARCHIVE)) {460 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));461 ei->attr |= EXFAT_ATTR_ARCHIVE;462 mark_inode_dirty(inode);463 }464 465 return err;466}467 468static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)469{470 struct address_space *mapping = iocb->ki_filp->f_mapping;471 struct inode *inode = mapping->host;472 struct exfat_inode_info *ei = EXFAT_I(inode);473 loff_t pos = iocb->ki_pos;474 loff_t size = pos + iov_iter_count(iter);475 int rw = iov_iter_rw(iter);476 ssize_t ret;477 478 /*479 * Need to use the DIO_LOCKING for avoiding the race480 * condition of exfat_get_block() and ->truncate().481 */482 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block);483 if (ret < 0) {484 if (rw == WRITE && ret != -EIOCBQUEUED)485 exfat_write_failed(mapping, size);486 487 return ret;488 } else489 size = pos + ret;490 491 if (rw == WRITE) {492 /*493 * If the block had been partially written before this write,494 * ->valid_size will not be updated in exfat_get_block(),495 * update it here.496 */497 if (ei->valid_size < size) {498 ei->valid_size = size;499 mark_inode_dirty(inode);500 }501 } else if (pos < ei->valid_size && ei->valid_size < size) {502 /* zero the unwritten part in the partially written block */503 iov_iter_revert(iter, size - ei->valid_size);504 iov_iter_zero(size - ei->valid_size, iter);505 }506 507 return ret;508}509 510static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block)511{512 sector_t blocknr;513 514 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */515 down_read(&EXFAT_I(mapping->host)->truncate_lock);516 blocknr = generic_block_bmap(mapping, block, exfat_get_block);517 up_read(&EXFAT_I(mapping->host)->truncate_lock);518 return blocknr;519}520 521/*522 * exfat_block_truncate_page() zeroes out a mapping from file offset `from'523 * up to the end of the block which corresponds to `from'.524 * This is required during truncate to physically zeroout the tail end525 * of that block so it doesn't yield old data if the file is later grown.526 * Also, avoid causing failure from fsx for cases of "data past EOF"527 */528int exfat_block_truncate_page(struct inode *inode, loff_t from)529{530 return block_truncate_page(inode->i_mapping, from, exfat_get_block);531}532 533static const struct address_space_operations exfat_aops = {534 .dirty_folio = block_dirty_folio,535 .invalidate_folio = block_invalidate_folio,536 .read_folio = exfat_read_folio,537 .readahead = exfat_readahead,538 .writepages = exfat_writepages,539 .write_begin = exfat_write_begin,540 .write_end = exfat_write_end,541 .direct_IO = exfat_direct_IO,542 .bmap = exfat_aop_bmap,543 .migrate_folio = buffer_migrate_folio,544};545 546static inline unsigned long exfat_hash(loff_t i_pos)547{548 return hash_32(i_pos, EXFAT_HASH_BITS);549}550 551void exfat_hash_inode(struct inode *inode, loff_t i_pos)552{553 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);554 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);555 556 spin_lock(&sbi->inode_hash_lock);557 EXFAT_I(inode)->i_pos = i_pos;558 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head);559 spin_unlock(&sbi->inode_hash_lock);560}561 562void exfat_unhash_inode(struct inode *inode)563{564 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);565 566 spin_lock(&sbi->inode_hash_lock);567 hlist_del_init(&EXFAT_I(inode)->i_hash_fat);568 EXFAT_I(inode)->i_pos = 0;569 spin_unlock(&sbi->inode_hash_lock);570}571 572struct inode *exfat_iget(struct super_block *sb, loff_t i_pos)573{574 struct exfat_sb_info *sbi = EXFAT_SB(sb);575 struct exfat_inode_info *info;576 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);577 struct inode *inode = NULL;578 579 spin_lock(&sbi->inode_hash_lock);580 hlist_for_each_entry(info, head, i_hash_fat) {581 WARN_ON(info->vfs_inode.i_sb != sb);582 583 if (i_pos != info->i_pos)584 continue;585 inode = igrab(&info->vfs_inode);586 if (inode)587 break;588 }589 spin_unlock(&sbi->inode_hash_lock);590 return inode;591}592 593/* doesn't deal with root inode */594static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)595{596 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);597 struct exfat_inode_info *ei = EXFAT_I(inode);598 loff_t size = info->size;599 600 ei->dir = info->dir;601 ei->entry = info->entry;602 ei->attr = info->attr;603 ei->start_clu = info->start_clu;604 ei->flags = info->flags;605 ei->type = info->type;606 ei->valid_size = info->valid_size;607 608 ei->version = 0;609 ei->hint_stat.eidx = 0;610 ei->hint_stat.clu = info->start_clu;611 ei->hint_femp.eidx = EXFAT_HINT_NONE;612 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;613 ei->i_pos = 0;614 615 inode->i_uid = sbi->options.fs_uid;616 inode->i_gid = sbi->options.fs_gid;617 inode_inc_iversion(inode);618 inode->i_generation = get_random_u32();619 620 if (info->attr & EXFAT_ATTR_SUBDIR) { /* directory */621 inode->i_generation &= ~1;622 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);623 inode->i_op = &exfat_dir_inode_operations;624 inode->i_fop = &exfat_dir_operations;625 set_nlink(inode, info->num_subdirs);626 } else { /* regular file */627 inode->i_generation |= 1;628 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);629 inode->i_op = &exfat_file_inode_operations;630 inode->i_fop = &exfat_file_operations;631 inode->i_mapping->a_ops = &exfat_aops;632 inode->i_mapping->nrpages = 0;633 }634 635 i_size_write(inode, size);636 637 exfat_save_attr(inode, info->attr);638 639 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;640 inode_set_mtime_to_ts(inode, info->mtime);641 inode_set_ctime_to_ts(inode, info->mtime);642 ei->i_crtime = info->crtime;643 inode_set_atime_to_ts(inode, info->atime);644 645 return 0;646}647 648struct inode *exfat_build_inode(struct super_block *sb,649 struct exfat_dir_entry *info, loff_t i_pos)650{651 struct inode *inode;652 int err;653 654 inode = exfat_iget(sb, i_pos);655 if (inode)656 goto out;657 inode = new_inode(sb);658 if (!inode) {659 inode = ERR_PTR(-ENOMEM);660 goto out;661 }662 inode->i_ino = iunique(sb, EXFAT_ROOT_INO);663 inode_set_iversion(inode, 1);664 err = exfat_fill_inode(inode, info);665 if (err) {666 iput(inode);667 inode = ERR_PTR(err);668 goto out;669 }670 exfat_hash_inode(inode, i_pos);671 insert_inode_hash(inode);672out:673 return inode;674}675 676void exfat_evict_inode(struct inode *inode)677{678 truncate_inode_pages(&inode->i_data, 0);679 680 if (!inode->i_nlink) {681 i_size_write(inode, 0);682 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);683 __exfat_truncate(inode);684 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);685 }686 687 invalidate_inode_buffers(inode);688 clear_inode(inode);689 exfat_cache_inval_inode(inode);690 exfat_unhash_inode(inode);691}692