// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*/
#include <linux/init.h>
#include <linux/buffer_head.h>
#include <linux/mpage.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/time.h>
#include <linux/writeback.h>
#include <linux/uio.h>
#include <linux/random.h>
#include <linux/iversion.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
int __exfat_write_inode(struct inode *inode, int sync)
{
unsigned long long on_disk_size;
struct exfat_dentry *ep, *ep2;
struct exfat_entry_set_cache es;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
bool is_dir = (ei->type == TYPE_DIR) ? true : false;
struct timespec64 ts;
if (inode->i_ino == EXFAT_ROOT_INO)
return 0;
/*
* If the inode is already unlinked, there is no need for updating it.
*/
if (ei->dir.dir == DIR_DELETED)
return 0;
if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1)
return 0;
exfat_set_volume_dirty(sb);
/* get the directory entry of given file or directory */
if (exfat_get_dentry_set(&es, sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES))
return -EIO;
ep = exfat_get_dentry_cached(&es, ES_IDX_FILE);
ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM);
ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));
/* set FILE_INFO structure using the acquired struct exfat_dentry */
exfat_set_entry_time(sbi, &ei->i_crtime,
&ep->dentry.file.create_tz,
&ep->dentry.file.create_time,
&ep->dentry.file.create_date,
&ep->dentry.file.create_time_cs);
ts = inode_get_mtime(inode);
exfat_set_entry_time(sbi, &ts,
&ep->dentry.file.modify_tz,
&ep->dentry.file.modify_time,
&ep->dentry.file.modify_date,
&ep->dentry.file.modify_time_cs);
ts = inode_get_atime(inode);
exfat_set_entry_time(sbi, &ts,
&ep->dentry.file.access_tz,
&ep->dentry.file.access_time,
&ep->dentry.file.access_date,
NULL);
/* File size should be zero if there is no cluster allocated */
on_disk_size = i_size_read(inode);
if (ei->start_clu == EXFAT_EOF_CLUSTER)
on_disk_size = 0;
ep2->dentry.stream.size = cpu_to_le64(on_disk_size);
/*
* mmap write does not use exfat_write_end(), valid_size may be
* extended to the sector-aligned length in exfat_get_block().
* So we need to fixup valid_size to the writren length.
*/
if (on_disk_size < ei->valid_size)
ep2->dentry.stream.valid_size = ep2->dentry.stream.size;
else
ep2->dentry.stream.valid_size = cpu_to_le64(ei->valid_size);
if (on_disk_size) {
ep2->dentry.stream.flags = ei->flags;
ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu);
} else {
ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
}
exfat_update_dir_chksum(&es);
return exfat_put_dentry_set(&es, sync);
}
int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
{
int ret;
if (unlikely(exfat_forced_shutdown(inode->i_sb)))
return -EIO;
mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
return ret;
}
void exfat_sync_inode(struct inode *inode)
{
lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock);
__exfat_write_inode(inode, 1);
}
/*
* Input: inode, (logical) clu_offset, target allocation area
* Output: errcode, cluster number
* *clu = (~0), if it's unable to allocate a new cluster
*/
static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
unsigned int *clu, int create)
{
int ret;
unsigned int last_clu;
struct exfat_chain new_clu;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
unsigned int local_clu_offset = clu_offset;
unsigned int num_to_be_allocated = 0, num_clusters;
num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
if (clu_offset >= num_clusters)
num_to_be_allocated = clu_offset - num_clusters + 1;
if (!create && (num_to_be_allocated > 0)) {
*clu = EXFAT_EOF_CLUSTER;
return 0;
}
*clu = last_clu = ei->start_clu;
if (ei->flags == ALLOC_NO_FAT_CHAIN) {
if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {
last_clu += clu_offset - 1;
if (clu_offset == num_clusters)
*clu = EXFAT_EOF_CLUSTER;
else
*clu += clu_offset;
}
} else if (ei->type == TYPE_FILE) {
unsigned int fclus = 0;
int err = exfat_get_cluster(inode, clu_offset,
&fclus, clu, &last_clu, 1);
if (err)
return -EIO;
clu_offset -= fclus;
} else {
/* hint information */
if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&
ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {
clu_offset -= ei->hint_bmap.off;
/* hint_bmap.clu should be valid */
WARN_ON(ei->hint_bmap.clu < 2);
*clu = ei->hint_bmap.clu;
}
while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {
last_clu = *clu;
if (exfat_get_next_cluster(sb, clu))
return -EIO;
clu_offset--;
}
}
if (*clu == EXFAT_EOF_CLUSTER) {
exfat_set_volume_dirty(sb);
new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
EXFAT_EOF_CLUSTER : last_clu + 1;
new_clu.size = 0;
new_clu.flags = ei->flags;
/* allocate a cluster */
if (num_to_be_allocated < 1) {
/* Broken FAT (i_sze > allocated FAT) */
exfat_fs_error(sb, "broken FAT chain.");
return -EIO;
}
ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu,
inode_needs_sync(inode));
if (ret)
return ret;
if (new_clu.dir == EXFAT_EOF_CLUSTER ||
new_clu.dir == EXFAT_FREE_CLUSTER) {
exfat_fs_error(sb,
"bogus cluster new allocated (last_clu : %u, new_clu : %u)",
last_clu, new_clu.dir);
return -EIO;
}
/* append to the FAT chain */
if (last_clu == EXFAT_EOF_CLUSTER) {
if (new_clu.flags == ALLOC_FAT_CHAIN)
ei->flags = ALLOC_FAT_CHAIN;
ei->start_clu = new_clu.dir;
} else {
if (new_clu.flags != ei->flags) {
/* no-fat-chain bit is disabled,
* so fat-chain should be synced with
* alloc-bitmap
*/
exfat_chain_cont_cluster(sb, ei->start_clu,
num_clusters);
ei->flags = ALLOC_FAT_CHAIN;
}
if (new_clu.flags == ALLOC_FAT_CHAIN)
if (exfat_ent_set(sb, last_clu, new_clu.dir))
return -EIO;
}
num_clusters += num_to_be_allocated;
*clu = new_clu.dir;
inode->i_blocks += EXFAT_CLU_TO_B(num_to_be_allocated, sbi) >> 9;
/*
* Move *clu pointer along FAT chains (hole care) because the
* caller of this function expect *clu to be the last cluster.
* This only works when num_to_be_allocated >= 2,
* *clu = (the first cluster of the allocated chain) =>
* (the last cluster of ...)
*/
if (ei->flags == ALLOC_NO_FAT_CHAIN) {
*clu += num_to_be_allocated - 1;
} else {
while (num_to_be_allocated > 1) {
if (exfat_get_next_cluster(sb, clu))
return -EIO;
num_to_be_allocated--;
}
}
}
/* hint information */
ei->hint_bmap.off = local_clu_offset;
ei->hint_bmap.clu = *clu;
return 0;
}
static int exfat_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct exfat_inode_info *ei = EXFAT_I(inode);
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
int err = 0;
unsigned long mapped_blocks = 0;
unsigned int cluster, sec_offset;
sector_t last_block;
sector_t phys = 0;
sector_t valid_blks;
mutex_lock(&sbi->s_lock);
last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb);
if (iblock >= last_block && !create)
goto done;
/* Is this block already allocated? */
err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits,
&cluster, create);
if (err) {
if (err != -ENOSPC)
exfat_fs_error_ratelimit(sb,
"failed to bmap (inode : %p iblock : %llu, err : %d)",
inode, (unsigned long long)iblock, err);
goto unlock_ret;
}
if (cluster == EXFAT_EOF_CLUSTER)
goto done;
/* sector offset in cluster */
sec_offset = iblock & (sbi->sect_per_clus - 1);
phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset;
mapped_blocks = sbi->sect_per_clus - sec_offset;
max_blocks = min(mapped_blocks, max_blocks);
map_bh(bh_result, sb, phys);
if (buffer_delay(bh_result))
clear_buffer_delay(bh_result);
if (create) {
valid_blks = EXFAT_B_TO_BLK_ROUND_UP(ei->valid_size, sb);
if (iblock + max_blocks < valid_blks) {
/* The range has been written, map it */
goto done;
} else if (iblock < valid_blks) {
/*
* The range has been partially written,
* map the written part.
*/
max_blocks = valid_blks - iblock;
goto done;
}
/* The area has not been written, map and mark as new. */
set_buffer_new(bh_result);
ei->valid_size = EXFAT_BLK_TO_B(iblock + max_blocks, sb);
mark_inode_dirty(inode);
} else {
valid_blks = EXFAT_B_TO_BLK(ei->valid_size, sb);
if (iblock + max_blocks < valid_blks) {
/* The range has been written, map it */
goto done;
} else if (iblock < valid_blks) {
/*
* The area has been partially written,
* map the written part.
*/
max_blocks = valid_blks - iblock;
goto done;
} else if (iblock == valid_blks &&
(ei->valid_size & (sb->s_blocksize - 1))) {
/*
* The block has been partially written,
* zero the unwritten part and map the block.
*/
loff_t size, off, pos;
max_blocks = 1;
/*
* For direct read, the unwritten part will be zeroed in
* exfat_direct_IO()
*/
if (!bh_result->b_folio)
goto done;
pos = EXFAT_BLK_TO_B(iblock, sb);
size = ei->valid_size - pos;
off = pos & (PAGE_SIZE - 1);
folio_set_bh(bh_result, bh_result->b_folio, off);
err = bh_read(bh_result, 0);
if (err < 0)
goto unlock_ret;
folio_zero_segment(bh_result->b_folio, off + size,
off + sb->s_blocksize);
} else {
/*
* The range has not been written, clear the mapped flag
* to only zero the cache and do not read from disk.
*/
clear_buffer_mapped(bh_result);
}
}
done:
bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
unlock_ret:
mutex_unlock(&sbi->s_lock);
return err;
}
static int exfat_read_folio(struct file *file, struct folio *folio)
{
return mpage_read_folio(folio, exfat_get_block);
}
static void exfat_readahead(struct readahead_control *rac)
{
struct address_space *mapping = rac->mapping;
struct inode *inode = mapping->host;
struct exfat_inode_info *ei = EXFAT_I(inode);
loff_t pos = readahead_pos(rac);
/* Range cross valid_size, read it page by page. */
if (ei->valid_size < i_size_read(inode) &&
pos <= ei->valid_size &&
ei->valid_size < pos + readahead_length(rac))
return;
mpage_readahead(rac, exfat_get_block);
}
static int exfat_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))
return -EIO;
return mpage_writepages(mapping, wbc, exfat_get_block);
}
static void exfat_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
if (to > i_size_read(inode)) {
truncate_pagecache(inode, i_size_read(inode));
inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
exfat_truncate(inode);
}
}
static int exfat_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned int len,
struct folio **foliop, void **fsdata)
{
int ret;
if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))
return -EIO;
ret = block_write_begin(mapping, pos, len, foliop, exfat_get_block);
if (ret < 0)
exfat_write_failed(mapping, pos+len);
return ret;
}
static int exfat_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned int len, unsigned int copied,
struct folio *folio, void *fsdata)
{
struct inode *inode = mapping->host;
struct exfat_inode_info *ei = EXFAT_I(inode);
int err;
err = generic_write_end(file, mapping, pos, len, copied, folio, fsdata);
if (err < len)
exfat_write_failed(mapping, pos+len);
if (!(err < 0) && pos + err > ei->valid_size) {
ei->valid_size = pos + err;
mark_inode_dirty(inode);
}
if (!(err < 0) && !(ei->attr & EXFAT_ATTR_ARCHIVE)) {
inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
ei->attr |= EXFAT_ATTR_ARCHIVE;
mark_inode_dirty(inode);
}
return err;
}
static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct address_space *mapping = iocb->ki_filp->f_mapping;
struct inode *inode = mapping->host;
struct exfat_inode_info *ei = EXFAT_I(inode);
loff_t pos = iocb->ki_pos;
loff_t size = pos + iov_iter_count(iter);
int rw = iov_iter_rw(iter);
ssize_t ret;
/*
* Need to use the DIO_LOCKING for avoiding the race
* condition of exfat_get_block() and ->truncate().
*/
ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block);
if (ret < 0) {
if (rw == WRITE && ret != -EIOCBQUEUED)
exfat_write_failed(mapping, size);
return ret;
} else
size = pos + ret;
if (rw == WRITE) {
/*
* If the block had been partially written before this write,
* ->valid_size will not be updated in exfat_get_block(),
* update it here.
*/
if (ei->valid_size < size) {
ei->valid_size = size;
mark_inode_dirty(inode);
}
} else if (pos < ei->valid_size && ei->valid_size < size) {
/* zero the unwritten part in the partially written block */
iov_iter_revert(iter, size - ei->valid_size);
iov_iter_zero(size - ei->valid_size, iter);
}
return ret;
}
static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block)
{
sector_t blocknr;
/* exfat_get_cluster() assumes the requested blocknr isn't truncated. */
down_read(&EXFAT_I(mapping->host)->truncate_lock);
blocknr = generic_block_bmap(mapping, block, exfat_get_block);
up_read(&EXFAT_I(mapping->host)->truncate_lock);
return blocknr;
}
/*
* exfat_block_truncate_page() zeroes out a mapping from file offset `from'
* up to the end of the block which corresponds to `from'.
* This is required during truncate to physically zeroout the tail end
* of that block so it doesn't yield old data if the file is later grown.
* Also, avoid causing failure from fsx for cases of "data past EOF"
*/
int exfat_block_truncate_page(struct inode *inode, loff_t from)
{
return block_truncate_page(inode->i_mapping, from, exfat_get_block);
}
static const struct address_space_operations exfat_aops = {
.dirty_folio = block_dirty_folio,
.invalidate_folio = block_invalidate_folio,
.read_folio = exfat_read_folio,
.readahead = exfat_readahead,
.writepages = exfat_writepages,
.write_begin = exfat_write_begin,
.write_end = exfat_write_end,
.direct_IO = exfat_direct_IO,
.bmap = exfat_aop_bmap,
.migrate_folio = buffer_migrate_folio,
};
static inline unsigned long exfat_hash(loff_t i_pos)
{
return hash_32(i_pos, EXFAT_HASH_BITS);
}
void exfat_hash_inode(struct inode *inode, loff_t i_pos)
{
struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
spin_lock(&sbi->inode_hash_lock);
EXFAT_I(inode)->i_pos = i_pos;
hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head);
spin_unlock(&sbi->inode_hash_lock);
}
void exfat_unhash_inode(struct inode *inode)
{
struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
spin_lock(&sbi->inode_hash_lock);
hlist_del_init(&EXFAT_I(inode)->i_hash_fat);
EXFAT_I(inode)->i_pos = 0;
spin_unlock(&sbi->inode_hash_lock);
}
struct inode *exfat_iget(struct super_block *sb, loff_t i_pos)
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *info;
struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
struct inode *inode = NULL;
spin_lock(&sbi->inode_hash_lock);
hlist_for_each_entry(info, head, i_hash_fat) {
WARN_ON(info->vfs_inode.i_sb != sb);
if (i_pos != info->i_pos)
continue;
inode = igrab(&info->vfs_inode);
if (inode)
break;
}
spin_unlock(&sbi->inode_hash_lock);
return inode;
}
/* doesn't deal with root inode */
static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
{
struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
loff_t size = info->size;
ei->dir = info->dir;
ei->entry = info->entry;
ei->attr = info->attr;
ei->start_clu = info->start_clu;
ei->flags = info->flags;
ei->type = info->type;
ei->valid_size = info->valid_size;
ei->version = 0;
ei->hint_stat.eidx = 0;
ei->hint_stat.clu = info->start_clu;
ei->hint_femp.eidx = EXFAT_HINT_NONE;
ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
ei->i_pos = 0;
inode->i_uid = sbi->options.fs_uid;
inode->i_gid = sbi->options.fs_gid;
inode_inc_iversion(inode);
inode->i_generation = get_random_u32();
if (info->attr & EXFAT_ATTR_SUBDIR) { /* directory */
inode->i_generation &= ~1;
inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
inode->i_op = &exfat_dir_inode_operations;
inode->i_fop = &exfat_dir_operations;
set_nlink(inode, info->num_subdirs);
} else { /* regular file */
inode->i_generation |= 1;
inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
inode->i_op = &exfat_file_inode_operations;
inode->i_fop = &exfat_file_operations;
inode->i_mapping->a_ops = &exfat_aops;
inode->i_mapping->nrpages = 0;
}
i_size_write(inode, size);
exfat_save_attr(inode, info->attr);
inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
inode_set_mtime_to_ts(inode, info->mtime);
inode_set_ctime_to_ts(inode, info->mtime);
ei->i_crtime = info->crtime;
inode_set_atime_to_ts(inode, info->atime);
return 0;
}
struct inode *exfat_build_inode(struct super_block *sb,
struct exfat_dir_entry *info, loff_t i_pos)
{
struct inode *inode;
int err;
inode = exfat_iget(sb, i_pos);
if (inode)
goto out;
inode = new_inode(sb);
if (!inode) {
inode = ERR_PTR(-ENOMEM);
goto out;
}
inode->i_ino = iunique(sb, EXFAT_ROOT_INO);
inode_set_iversion(inode, 1);
err = exfat_fill_inode(inode, info);
if (err) {
iput(inode);
inode = ERR_PTR(err);
goto out;
}
exfat_hash_inode(inode, i_pos);
insert_inode_hash(inode);
out:
return inode;
}
void exfat_evict_inode(struct inode *inode)
{
truncate_inode_pages(&inode->i_data, 0);
if (!inode->i_nlink) {
i_size_write(inode, 0);
mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
__exfat_truncate(inode);
mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
}
invalidate_inode_buffers(inode);
clear_inode(inode);
exfat_cache_inval_inode(inode);
exfat_unhash_inode(inode);
}
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