linux/fs/exfat/inode.c
Namjae Jeon 5f2aa07507 exfat: add inode operations
This adds the implementation of inode operations for exfat.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-05 21:00:40 -05:00

672 lines
17 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"
static int __exfat_write_inode(struct inode *inode, int sync)
{
int ret = -EIO;
unsigned long long on_disk_size;
struct exfat_dentry *ep, *ep2;
struct exfat_entry_set_cache *es = NULL;
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;
if (inode->i_ino == EXFAT_ROOT_INO)
return 0;
/*
* If the indode 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_vol_flags(sb, VOL_DIRTY);
/* get the directory entry of given file or directory */
es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES,
&ep);
if (!es)
return -EIO;
ep2 = ep + 1;
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_ms);
exfat_set_entry_time(sbi, &inode->i_mtime,
&ep->dentry.file.modify_tz,
&ep->dentry.file.modify_time,
&ep->dentry.file.modify_date,
&ep->dentry.file.modify_time_ms);
exfat_set_entry_time(sbi, &inode->i_atime,
&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.valid_size = cpu_to_le64(on_disk_size);
ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
ret = exfat_update_dir_chksum_with_entry_set(sb, es, sync);
kfree(es);
return ret;
}
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, modified = false;
unsigned int last_clu;
struct exfat_chain new_clu;
struct exfat_dentry *ep;
struct exfat_entry_set_cache *es = NULL;
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;
ei->rwoffset = EXFAT_CLU_TO_B(clu_offset, sbi);
if (EXFAT_I(inode)->i_size_ondisk > 0)
num_clusters =
EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->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_vol_flags(sb, VOL_DIRTY);
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);
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;
modified = true;
} 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;
modified = true;
}
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;
if (ei->dir.dir != DIR_DELETED) {
es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
ES_ALL_ENTRIES, &ep);
if (!es)
return -EIO;
/* get stream entry */
ep++;
/* update directory entry */
if (modified) {
if (ep->dentry.stream.flags != ei->flags)
ep->dentry.stream.flags = ei->flags;
if (le32_to_cpu(ep->dentry.stream.start_clu) !=
ei->start_clu)
ep->dentry.stream.start_clu =
cpu_to_le32(ei->start_clu);
ep->dentry.stream.valid_size =
cpu_to_le64(i_size_read(inode));
ep->dentry.stream.size =
ep->dentry.stream.valid_size;
}
if (exfat_update_dir_chksum_with_entry_set(sb, es,
inode_needs_sync(inode)))
return -EIO;
kfree(es);
} /* end of if != DIR_DELETED */
inode->i_blocks +=
num_to_be_allocated << sbi->sect_per_clus_bits;
/*
* 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;
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);
/* Treat newly added block / cluster */
if (iblock < last_block)
create = 0;
if (create || buffer_delay(bh_result)) {
pos = EXFAT_BLK_TO_B((iblock + 1), sb);
if (ei->i_size_ondisk < pos)
ei->i_size_ondisk = pos;
}
if (create) {
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;
}
}
if (buffer_delay(bh_result))
clear_buffer_delay(bh_result);
map_bh(bh_result, sb, phys);
done:
bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
unlock_ret:
mutex_unlock(&sbi->s_lock);
return err;
}
static int exfat_readpage(struct file *file, struct page *page)
{
return mpage_readpage(page, exfat_get_block);
}
static int exfat_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned int nr_pages)
{
return mpage_readpages(mapping, pages, nr_pages, exfat_get_block);
}
static int exfat_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, exfat_get_block, wbc);
}
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));
exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned);
}
}
static int exfat_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned int len, unsigned int flags,
struct page **pagep, void **fsdata)
{
int ret;
*pagep = NULL;
ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
exfat_get_block,
&EXFAT_I(mapping->host)->i_size_ondisk);
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 (EXFAT_I(inode)->i_size_aligned < i_size_read(inode)) {
exfat_fs_error(inode->i_sb,
"invalid size(size(%llu) > aligned(%llu)\n",
i_size_read(inode), EXFAT_I(inode)->i_size_aligned);
return -EIO;
}
if (err < len)
exfat_write_failed(mapping, pos+len);
if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) {
inode->i_mtime = inode->i_ctime = current_time(inode);
ei->attr |= 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;
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 && (rw & WRITE))
exfat_write_failed(mapping, size);
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 = {
.readpage = exfat_readpage,
.readpages = exfat_readpages,
.writepage = exfat_writepage,
.writepages = exfat_writepages,
.write_begin = exfat_write_begin,
.write_end = exfat_write_end,
.direct_IO = exfat_direct_IO,
.bmap = exfat_aop_bmap
};
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;
memcpy(&ei->dir, &info->dir, sizeof(struct exfat_chain));
ei->entry = info->entry;
ei->attr = info->attr;
ei->start_clu = info->start_clu;
ei->flags = info->flags;
ei->type = info->type;
ei->version = 0;
ei->hint_stat.eidx = 0;
ei->hint_stat.clu = info->start_clu;
ei->hint_femp.eidx = EXFAT_HINT_NONE;
ei->rwoffset = 0;
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 = prandom_u32();
if (info->attr & 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 = ((i_size_read(inode) + (sbi->cluster_size - 1)) &
~(sbi->cluster_size - 1)) >> inode->i_blkbits;
inode->i_mtime = info->mtime;
inode->i_ctime = info->mtime;
ei->i_crtime = info->crtime;
inode->i_atime = info->atime;
exfat_cache_init_inode(inode);
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, 0);
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);
}