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linux/fs/exfat/fatent.c
Al Viro 5f60d5f6bb move asm/unaligned.h to linux/unaligned.h 
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-10-02 17:23:23 -04:00

452 lines
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*/
#include <linux/slab.h>
#include <linux/unaligned.h>
#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
static int exfat_mirror_bh(struct super_block *sb, sector_t sec,
struct buffer_head *bh)
{
struct buffer_head *c_bh;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
sector_t sec2;
int err = 0;
if (sbi->FAT2_start_sector != sbi->FAT1_start_sector) {
sec2 = sec - sbi->FAT1_start_sector + sbi->FAT2_start_sector;
c_bh = sb_getblk(sb, sec2);
if (!c_bh)
return -ENOMEM;
memcpy(c_bh->b_data, bh->b_data, sb->s_blocksize);
set_buffer_uptodate(c_bh);
mark_buffer_dirty(c_bh);
if (sb->s_flags & SB_SYNCHRONOUS)
err = sync_dirty_buffer(c_bh);
brelse(c_bh);
}
return err;
}
static int __exfat_ent_get(struct super_block *sb, unsigned int loc,
unsigned int *content)
{
unsigned int off;
sector_t sec;
struct buffer_head *bh;
sec = FAT_ENT_OFFSET_SECTOR(sb, loc);
off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc);
bh = sb_bread(sb, sec);
if (!bh)
return -EIO;
*content = le32_to_cpu(*(__le32 *)(&bh->b_data[off]));
/* remap reserved clusters to simplify code */
if (*content > EXFAT_BAD_CLUSTER)
*content = EXFAT_EOF_CLUSTER;
brelse(bh);
return 0;
}
int exfat_ent_set(struct super_block *sb, unsigned int loc,
unsigned int content)
{
unsigned int off;
sector_t sec;
__le32 *fat_entry;
struct buffer_head *bh;
sec = FAT_ENT_OFFSET_SECTOR(sb, loc);
off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc);
bh = sb_bread(sb, sec);
if (!bh)
return -EIO;
fat_entry = (__le32 *)&(bh->b_data[off]);
*fat_entry = cpu_to_le32(content);
exfat_update_bh(bh, sb->s_flags & SB_SYNCHRONOUS);
exfat_mirror_bh(sb, sec, bh);
brelse(bh);
return 0;
}
int exfat_ent_get(struct super_block *sb, unsigned int loc,
unsigned int *content)
{
struct exfat_sb_info *sbi = EXFAT_SB(sb);
int err;
if (!is_valid_cluster(sbi, loc)) {
exfat_fs_error(sb, "invalid access to FAT (entry 0x%08x)",
loc);
return -EIO;
}
err = __exfat_ent_get(sb, loc, content);
if (err) {
exfat_fs_error(sb,
"failed to access to FAT (entry 0x%08x, err:%d)",
loc, err);
return err;
}
if (*content == EXFAT_FREE_CLUSTER) {
exfat_fs_error(sb,
"invalid access to FAT free cluster (entry 0x%08x)",
loc);
return -EIO;
}
if (*content == EXFAT_BAD_CLUSTER) {
exfat_fs_error(sb,
"invalid access to FAT bad cluster (entry 0x%08x)",
loc);
return -EIO;
}
if (*content != EXFAT_EOF_CLUSTER && !is_valid_cluster(sbi, *content)) {
exfat_fs_error(sb,
"invalid access to FAT (entry 0x%08x) bogus content (0x%08x)",
loc, *content);
return -EIO;
}
return 0;
}
int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
unsigned int len)
{
if (!len)
return 0;
while (len > 1) {
if (exfat_ent_set(sb, chain, chain + 1))
return -EIO;
chain++;
len--;
}
if (exfat_ent_set(sb, chain, EXFAT_EOF_CLUSTER))
return -EIO;
return 0;
}
/* This function must be called with bitmap_lock held */
static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
{
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
int cur_cmap_i, next_cmap_i;
unsigned int num_clusters = 0;
unsigned int clu;
/* invalid cluster number */
if (p_chain->dir == EXFAT_FREE_CLUSTER ||
p_chain->dir == EXFAT_EOF_CLUSTER ||
p_chain->dir < EXFAT_FIRST_CLUSTER)
return 0;
/* no cluster to truncate */
if (p_chain->size == 0)
return 0;
/* check cluster validation */
if (!is_valid_cluster(sbi, p_chain->dir)) {
exfat_err(sb, "invalid start cluster (%u)", p_chain->dir);
return -EIO;
}
clu = p_chain->dir;
cur_cmap_i = next_cmap_i =
BITMAP_OFFSET_SECTOR_INDEX(sb, CLUSTER_TO_BITMAP_ENT(clu));
if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
unsigned int last_cluster = p_chain->dir + p_chain->size - 1;
do {
bool sync = false;
if (clu < last_cluster)
next_cmap_i =
BITMAP_OFFSET_SECTOR_INDEX(sb, CLUSTER_TO_BITMAP_ENT(clu+1));
/* flush bitmap only if index would be changed or for last cluster */
if (clu == last_cluster || cur_cmap_i != next_cmap_i) {
sync = true;
cur_cmap_i = next_cmap_i;
}
exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode)));
clu++;
num_clusters++;
} while (num_clusters < p_chain->size);
} else {
do {
bool sync = false;
unsigned int n_clu = clu;
int err = exfat_get_next_cluster(sb, &n_clu);
if (err || n_clu == EXFAT_EOF_CLUSTER)
sync = true;
else
next_cmap_i =
BITMAP_OFFSET_SECTOR_INDEX(sb, CLUSTER_TO_BITMAP_ENT(n_clu));
if (cur_cmap_i != next_cmap_i) {
sync = true;
cur_cmap_i = next_cmap_i;
}
exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode)));
clu = n_clu;
num_clusters++;
if (err)
goto dec_used_clus;
} while (clu != EXFAT_EOF_CLUSTER);
}
dec_used_clus:
sbi->used_clusters -= num_clusters;
return 0;
}
int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
{
int ret = 0;
mutex_lock(&EXFAT_SB(inode->i_sb)->bitmap_lock);
ret = __exfat_free_cluster(inode, p_chain);
mutex_unlock(&EXFAT_SB(inode->i_sb)->bitmap_lock);
return ret;
}
int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
unsigned int *ret_clu)
{
unsigned int clu, next;
unsigned int count = 0;
next = p_chain->dir;
if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
*ret_clu = next + p_chain->size - 1;
return 0;
}
do {
count++;
clu = next;
if (exfat_ent_get(sb, clu, &next))
return -EIO;
} while (next != EXFAT_EOF_CLUSTER);
if (p_chain->size != count) {
exfat_fs_error(sb,
"bogus directory size (clus : ondisk(%d) != counted(%d))",
p_chain->size, count);
return -EIO;
}
*ret_clu = clu;
return 0;
}
int exfat_zeroed_cluster(struct inode *dir, unsigned int clu)
{
struct super_block *sb = dir->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct buffer_head *bh;
sector_t blknr, last_blknr, i;
blknr = exfat_cluster_to_sector(sbi, clu);
last_blknr = blknr + sbi->sect_per_clus;
if (last_blknr > sbi->num_sectors && sbi->num_sectors > 0) {
exfat_fs_error_ratelimit(sb,
"%s: out of range(sect:%llu len:%u)",
__func__, (unsigned long long)blknr,
sbi->sect_per_clus);
return -EIO;
}
/* Zeroing the unused blocks on this cluster */
for (i = blknr; i < last_blknr; i++) {
bh = sb_getblk(sb, i);
if (!bh)
return -ENOMEM;
memset(bh->b_data, 0, sb->s_blocksize);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
brelse(bh);
}
if (IS_DIRSYNC(dir))
return sync_blockdev_range(sb->s_bdev,
EXFAT_BLK_TO_B(blknr, sb),
EXFAT_BLK_TO_B(last_blknr, sb) - 1);
return 0;
}
int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
struct exfat_chain *p_chain, bool sync_bmap)
{
int ret = -ENOSPC;
unsigned int total_cnt;
unsigned int hint_clu, new_clu, last_clu = EXFAT_EOF_CLUSTER;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
total_cnt = EXFAT_DATA_CLUSTER_COUNT(sbi);
if (unlikely(total_cnt < sbi->used_clusters)) {
exfat_fs_error_ratelimit(sb,
"%s: invalid used clusters(t:%u,u:%u)\n",
__func__, total_cnt, sbi->used_clusters);
return -EIO;
}
if (num_alloc > total_cnt - sbi->used_clusters)
return -ENOSPC;
mutex_lock(&sbi->bitmap_lock);
hint_clu = p_chain->dir;
/* find new cluster */
if (hint_clu == EXFAT_EOF_CLUSTER) {
if (sbi->clu_srch_ptr < EXFAT_FIRST_CLUSTER) {
exfat_err(sb, "sbi->clu_srch_ptr is invalid (%u)",
sbi->clu_srch_ptr);
sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
}
hint_clu = exfat_find_free_bitmap(sb, sbi->clu_srch_ptr);
if (hint_clu == EXFAT_EOF_CLUSTER) {
ret = -ENOSPC;
goto unlock;
}
}
/* check cluster validation */
if (!is_valid_cluster(sbi, hint_clu)) {
if (hint_clu != sbi->num_clusters)
exfat_err(sb, "hint_cluster is invalid (%u), rewind to the first cluster",
hint_clu);
hint_clu = EXFAT_FIRST_CLUSTER;
p_chain->flags = ALLOC_FAT_CHAIN;
}
p_chain->dir = EXFAT_EOF_CLUSTER;
while ((new_clu = exfat_find_free_bitmap(sb, hint_clu)) !=
EXFAT_EOF_CLUSTER) {
if (new_clu != hint_clu &&
p_chain->flags == ALLOC_NO_FAT_CHAIN) {
if (exfat_chain_cont_cluster(sb, p_chain->dir,
p_chain->size)) {
ret = -EIO;
goto free_cluster;
}
p_chain->flags = ALLOC_FAT_CHAIN;
}
/* update allocation bitmap */
if (exfat_set_bitmap(inode, new_clu, sync_bmap)) {
ret = -EIO;
goto free_cluster;
}
/* update FAT table */
if (p_chain->flags == ALLOC_FAT_CHAIN) {
if (exfat_ent_set(sb, new_clu, EXFAT_EOF_CLUSTER)) {
ret = -EIO;
goto free_cluster;
}
}
if (p_chain->dir == EXFAT_EOF_CLUSTER) {
p_chain->dir = new_clu;
} else if (p_chain->flags == ALLOC_FAT_CHAIN) {
if (exfat_ent_set(sb, last_clu, new_clu)) {
ret = -EIO;
goto free_cluster;
}
}
p_chain->size++;
last_clu = new_clu;
if (p_chain->size == num_alloc) {
sbi->clu_srch_ptr = hint_clu;
sbi->used_clusters += num_alloc;
mutex_unlock(&sbi->bitmap_lock);
return 0;
}
hint_clu = new_clu + 1;
if (hint_clu >= sbi->num_clusters) {
hint_clu = EXFAT_FIRST_CLUSTER;
if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
if (exfat_chain_cont_cluster(sb, p_chain->dir,
p_chain->size)) {
ret = -EIO;
goto free_cluster;
}
p_chain->flags = ALLOC_FAT_CHAIN;
}
}
}
free_cluster:
__exfat_free_cluster(inode, p_chain);
unlock:
mutex_unlock(&sbi->bitmap_lock);
return ret;
}
int exfat_count_num_clusters(struct super_block *sb,
struct exfat_chain *p_chain, unsigned int *ret_count)
{
unsigned int i, count;
unsigned int clu;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
if (!p_chain->dir || p_chain->dir == EXFAT_EOF_CLUSTER) {
*ret_count = 0;
return 0;
}
if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
*ret_count = p_chain->size;
return 0;
}
clu = p_chain->dir;
count = 0;
for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters; i++) {
count++;
if (exfat_ent_get(sb, clu, &clu))
return -EIO;
if (clu == EXFAT_EOF_CLUSTER)
break;
}
*ret_count = count;
return 0;
}
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