linux/fs/exfat/inode.c
Yuezhang Mo f55c096f62 exfat: do not zero the extended part
Since the read operation beyond the ValidDataLength returns zero,
if we just extend the size of the file, we don't need to zero the
extended part, but only change the DataLength without changing
the ValidDataLength.

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2024-01-08 21:57:22 +09:00

736 lines
19 KiB
C

// 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_with_entry_set(&es);
return exfat_put_dentry_set(&es, sync);
}
int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
{
int ret;
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 = 0;
if (ei->i_size_ondisk > 0)
num_clusters =
EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, 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_map_new_buffer(struct exfat_inode_info *ei,
struct buffer_head *bh, loff_t pos)
{
if (buffer_delay(bh) && pos > ei->i_size_aligned)
return -EIO;
set_buffer_new(bh);
/*
* Adjust i_size_aligned if i_size_ondisk is bigger than it.
*/
if (ei->i_size_ondisk > ei->i_size_aligned)
ei->i_size_aligned = ei->i_size_ondisk;
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;
loff_t pos;
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);
pos = EXFAT_BLK_TO_B((iblock + 1), sb);
if ((create && iblock >= last_block) || buffer_delay(bh_result)) {
if (ei->i_size_ondisk < pos)
ei->i_size_ondisk = pos;
}
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. */
err = exfat_map_new_buffer(ei, bh_result, pos);
if (err) {
exfat_fs_error(sb,
"requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n",
pos, ei->i_size_aligned);
goto unlock_ret;
}
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;
max_blocks = 1;
/*
* For direct read, the unwritten part will be zeroed in
* exfat_direct_IO()
*/
if (!bh_result->b_folio)
goto done;
pos -= sb->s_blocksize;
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)
{
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 page **pagep, void **fsdata)
{
int ret;
*pagep = NULL;
ret = block_write_begin(mapping, pos, len, pagep, 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 page *pagep, 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, pagep, fsdata);
if (ei->i_size_aligned < i_size_read(inode)) {
exfat_fs_error(inode->i_sb,
"invalid size(size(%llu) > aligned(%llu)\n",
i_size_read(inode), ei->i_size_aligned);
return -EIO;
}
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 = iocb->ki_pos + iov_iter_count(iter);
int rw = iov_iter_rw(iter);
ssize_t ret;
if (rw == WRITE) {
/*
* FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
* so we need to update the ->i_size_aligned to block boundary.
*
* But we must fill the remaining area or hole by nul for
* updating ->i_size_aligned
*
* Return 0, and fallback to normal buffered write.
*/
if (EXFAT_I(inode)->i_size_aligned < size)
return 0;
}
/*
* 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)
exfat_write_failed(mapping, size);
if (ret != -EIOCBQUEUED)
return ret;
} else
size = pos + ret;
/* zero the unwritten part in the partially written block */
if (rw == READ && pos < ei->valid_size && ei->valid_size < size) {
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);
/* ondisk and aligned size should be aligned with block size */
if (size & (inode->i_sb->s_blocksize - 1)) {
size |= (inode->i_sb->s_blocksize - 1);
size++;
}
ei->i_size_aligned = size;
ei->i_size_ondisk = 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);
}