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core.c
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core.c
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/*
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/************************************************************************/
/* */
/* PROJECT : exFAT & FAT12/16/32 File System */
/* FILE : core.c */
/* PURPOSE : FAT & exFAT common core code for sdFAT */
/* */
/*----------------------------------------------------------------------*/
/* NOTES */
/* */
/* */
/************************************************************************/
#include <linux/version.h>
#include <linux/blkdev.h>
#include <linux/workqueue.h>
#include <linux/writeback.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include "sdfat.h"
#include "core.h"
#include <asm/byteorder.h>
#include <asm/unaligned.h>
/*----------------------------------------------------------------------*/
/* Constant & Macro Definitions */
/*----------------------------------------------------------------------*/
static inline void __set_sb_dirty(struct super_block *sb)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)
sb->s_dirt = 1;
#else /* LINUX_VERSION_CODE >= KERNEL_VERSION(3, 7, 0) */
struct sdfat_sb_info *sbi = SDFAT_SB(sb);
sbi->s_dirt = 1;
/* Insert work */
spin_lock(&sbi->work_lock);
if (!sbi->write_super_queued) {
unsigned long delay;
delay = msecs_to_jiffies(CONFIG_SDFAT_WRITE_SB_INTERVAL_CSECS * 10);
queue_delayed_work(system_long_wq, &sbi->write_super_work, delay);
sbi->write_super_queued = 1;
}
spin_unlock(&sbi->work_lock);
#endif
}
void set_sb_dirty(struct super_block *sb)
{
__set_sb_dirty(sb);
// XXX: to be removed later, prints too much output
//TMSG("%s finished.\n", __func__);
}
/*----------------------------------------------------------------------*/
/* Global Variable Definitions */
/*----------------------------------------------------------------------*/
/*----------------------------------------------------------------------*/
/* Local Variable Definitions */
/*----------------------------------------------------------------------*/
static s8 *reserved_names[] = {
"AUX ", "CON ", "NUL ", "PRN ",
"COM1 ", "COM2 ", "COM3 ", "COM4 ",
"COM5 ", "COM6 ", "COM7 ", "COM8 ", "COM9 ",
"LPT1 ", "LPT2 ", "LPT3 ", "LPT4 ",
"LPT5 ", "LPT6 ", "LPT7 ", "LPT8 ", "LPT9 ",
NULL
};
/*======================================================================*/
/* Local Function Definitions */
/*======================================================================*/
/*
* File System Management Functions
*/
static s32 check_type_size(void)
{
/* critical check for system requirement on size of DENTRY_T structure */
if (sizeof(DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
if (sizeof(DOS_DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
if (sizeof(EXT_DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
if (sizeof(FILE_DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
if (sizeof(STRM_DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
if (sizeof(NAME_DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
if (sizeof(BMAP_DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
if (sizeof(CASE_DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
if (sizeof(VOLM_DENTRY_T) != DENTRY_SIZE)
return -EINVAL;
return 0;
}
static s32 __fs_set_vol_flags(struct super_block *sb, u16 new_flag, s32 always_sync)
{
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
s32 err;
s32 sync = 0;
/* flags are not changed */
if (fsi->vol_flag == new_flag)
return 0;
fsi->vol_flag = new_flag;
/* skip updating volume dirty flag,
* if this volume has been mounted with read-only
*/
if (SDFAT_IS_SB_RDONLY(sb))
return 0;
if (!fsi->pbr_bh) {
err = read_sect(sb, 0, &(fsi->pbr_bh), 1);
if (err) {
EMSG("%s : failed to read boot sector\n", __func__);
return err;
}
}
if (fsi->vol_type == EXFAT) {
pbr64_t *bpb = (pbr64_t *)fsi->pbr_bh->b_data;
bpb->bsx.vol_flags = cpu_to_le16(new_flag);
} else if (fsi->vol_type == FAT32) {
pbr32_t *bpb = (pbr32_t *)fsi->pbr_bh->b_data;
bpb->bsx.state = new_flag & VOL_DIRTY ? FAT_VOL_DIRTY : 0x00;
} else { /* FAT16/12 */
pbr16_t *bpb = (pbr16_t *) fsi->pbr_bh->b_data;
bpb->bpb.state = new_flag & VOL_DIRTY ? FAT_VOL_DIRTY : 0x00;
}
if (always_sync)
sync = 1;
else if ((new_flag == VOL_DIRTY) && (!buffer_dirty(fsi->pbr_bh)))
sync = 1;
else
sync = 0;
err = write_sect(sb, 0, fsi->pbr_bh, sync);
if (err)
EMSG("%s : failed to modify volume flag\n", __func__);
return err;
}
static s32 fs_set_vol_flags(struct super_block *sb, u16 new_flag)
{
return __fs_set_vol_flags(sb, new_flag, 0);
}
s32 fscore_set_vol_flags(struct super_block *sb, u16 new_flag, s32 always_sync)
{
return __fs_set_vol_flags(sb, new_flag, always_sync);
}
static inline s32 __fs_meta_sync(struct super_block *sb, s32 do_sync)
{
#ifdef CONFIG_SDFAT_DELAYED_META_DIRTY
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
if (fsi->vol_type != EXFAT) {
MMSG("meta flush in fs_sync(sync=%d)\n", do_sync);
fcache_flush(sb, 0);
dcache_flush(sb, 0);
}
#else
/* DO NOTHING */
#endif
return 0;
}
static s32 fs_sync(struct super_block *sb, s32 do_sync)
{
s32 err;
if (!do_sync)
return 0;
err = __fs_meta_sync(sb, do_sync);
if (!err)
err = bdev_sync_all(sb);
if (err)
EMSG("%s : failed to sync. (err:%d)\n", __func__, err);
return err;
}
/*
* Cluster Management Functions
*/
static s32 __clear_cluster(struct inode *inode, u32 clu)
{
u64 s, n;
struct super_block *sb = inode->i_sb;
u32 sect_size = (u32)sb->s_blocksize;
s32 ret = 0;
struct buffer_head *tmp_bh = NULL;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
if (IS_CLUS_FREE(clu)) { /* FAT16 root_dir */
s = fsi->root_start_sector;
n = fsi->data_start_sector;
} else {
s = CLUS_TO_SECT(fsi, clu);
n = s + fsi->sect_per_clus;
}
if (IS_DIRSYNC(inode)) {
ret = write_msect_zero(sb, s, (u64)fsi->sect_per_clus);
if (ret != -EAGAIN)
return ret;
}
/* Trying buffered zero writes
* if it doesn't have DIRSYNC or write_msect_zero() returned -EAGAIN
*/
for ( ; s < n; s++) {
#if 0
dcache_release(sb, s);
#endif
ret = read_sect(sb, s, &tmp_bh, 0);
if (ret)
goto out;
memset((u8 *)tmp_bh->b_data, 0x0, sect_size);
ret = write_sect(sb, s, tmp_bh, 0);
if (ret)
goto out;
}
out:
brelse(tmp_bh);
return ret;
} /* end of __clear_cluster */
static s32 __find_last_cluster(struct super_block *sb, CHAIN_T *p_chain, u32 *ret_clu)
{
u32 clu, next;
u32 count = 0;
next = p_chain->dir;
if (p_chain->flags == 0x03) {
*ret_clu = next + p_chain->size - 1;
return 0;
}
do {
count++;
clu = next;
if (fat_ent_get_safe(sb, clu, &next))
return -EIO;
} while (!IS_CLUS_EOF(next));
if (p_chain->size != count) {
sdfat_fs_error(sb, "bogus directory size "
"(clus : ondisk(%d) != counted(%d))",
p_chain->size, count);
sdfat_debug_bug_on(1);
return -EIO;
}
*ret_clu = clu;
return 0;
}
static s32 __count_num_clusters(struct super_block *sb, CHAIN_T *p_chain, u32 *ret_count)
{
u32 i, count;
u32 clu;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
if (!p_chain->dir || IS_CLUS_EOF(p_chain->dir)) {
*ret_count = 0;
return 0;
}
if (p_chain->flags == 0x03) {
*ret_count = p_chain->size;
return 0;
}
clu = p_chain->dir;
count = 0;
for (i = CLUS_BASE; i < fsi->num_clusters; i++) {
count++;
if (fat_ent_get_safe(sb, clu, &clu))
return -EIO;
if (IS_CLUS_EOF(clu))
break;
}
*ret_count = count;
return 0;
}
/*
* Upcase table Management Functions
*/
static void free_upcase_table(struct super_block *sb)
{
u32 i;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
u16 **upcase_table;
upcase_table = fsi->vol_utbl;
for (i = 0 ; i < UTBL_COL_COUNT ; i++) {
/* kfree(NULL) is safe */
kfree(upcase_table[i]);
upcase_table[i] = NULL;
}
/* kfree(NULL) is safe */
kfree(fsi->vol_utbl);
fsi->vol_utbl = NULL;
}
static s32 __load_upcase_table(struct super_block *sb, u64 sector, u64 num_sectors, u32 utbl_checksum)
{
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
struct buffer_head *tmp_bh = NULL;
u32 sect_size = (u32)sb->s_blocksize;
s32 ret = -EIO;
u32 i, j;
u8 skip = false;
u32 index = 0;
u32 checksum = 0;
u16 **upcase_table = kzalloc((UTBL_COL_COUNT * sizeof(u16 *)), GFP_KERNEL);
if (!upcase_table)
return -ENOMEM;
/* thanks for kzalloc
* memset(upcase_table, 0, UTBL_COL_COUNT * sizeof(u16 *));
*/
fsi->vol_utbl = upcase_table;
num_sectors += sector;
while (sector < num_sectors) {
ret = read_sect(sb, sector, &tmp_bh, 1);
if (ret) {
EMSG("%s: failed to read sector(0x%llx)\n",
__func__, sector);
goto error;
}
sector++;
for (i = 0; i < sect_size && index <= 0xFFFF; i += 2) {
/* FIXME : is __le16 ok? */
//u16 uni = le16_to_cpu(((__le16*)(tmp_bh->b_data))[i]);
u16 uni = get_unaligned_le16((u8 *)tmp_bh->b_data+i);
checksum = ((checksum & 1) ? 0x80000000 : 0) +
(checksum >> 1) + *(((u8 *)tmp_bh->b_data)+i);
checksum = ((checksum & 1) ? 0x80000000 : 0) +
(checksum >> 1) + *(((u8 *)tmp_bh->b_data)+(i+1));
if (skip) {
MMSG("skip from 0x%X to 0x%X(amount of 0x%X)\n",
index, index+uni, uni);
index += uni;
skip = false;
} else if (uni == index) {
index++;
} else if (uni == 0xFFFF) {
skip = true;
} else { /* uni != index , uni != 0xFFFF */
u16 col_index = get_col_index(index);
if (!upcase_table[col_index]) {
upcase_table[col_index] =
kmalloc((UTBL_ROW_COUNT * sizeof(u16)), GFP_KERNEL);
if (!upcase_table[col_index]) {
EMSG("failed to allocate memory"
" for column 0x%X\n",
col_index);
ret = -ENOMEM;
goto error;
}
for (j = 0; j < UTBL_ROW_COUNT; j++)
upcase_table[col_index][j] = (col_index << LOW_INDEX_BIT) | j;
}
upcase_table[col_index][get_row_index(index)] = uni;
index++;
}
}
}
if (index >= 0xFFFF && utbl_checksum == checksum) {
DMSG("%s: load upcase table successfully"
"(idx:0x%08x, utbl_chksum:0x%08x)\n",
__func__, index, utbl_checksum);
if (tmp_bh)
brelse(tmp_bh);
return 0;
}
EMSG("%s: failed to load upcase table"
"(idx:0x%08x, chksum:0x%08x, utbl_chksum:0x%08x)\n",
__func__, index, checksum, utbl_checksum);
ret = -EINVAL;
error:
if (tmp_bh)
brelse(tmp_bh);
free_upcase_table(sb);
return ret;
}
static s32 __load_default_upcase_table(struct super_block *sb)
{
s32 i, ret = -EIO;
u32 j;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
u8 skip = false;
u32 index = 0;
u16 uni = 0;
u16 **upcase_table;
upcase_table = kmalloc((UTBL_COL_COUNT * sizeof(u16 *)), GFP_KERNEL);
if (!upcase_table)
return -ENOMEM;
fsi->vol_utbl = upcase_table;
memset(upcase_table, 0, UTBL_COL_COUNT * sizeof(u16 *));
for (i = 0; index <= 0xFFFF && i < SDFAT_NUM_UPCASE*2; i += 2) {
/* FIXME : is __le16 ok? */
//uni = le16_to_cpu(((__le16*)uni_def_upcase)[i>>1]);
uni = get_unaligned_le16((u8 *)uni_def_upcase+i);
if (skip) {
MMSG("skip from 0x%x ", index);
index += uni;
MMSG("to 0x%x (amount of 0x%x)\n", index, uni);
skip = false;
} else if (uni == index) {
index++;
} else if (uni == 0xFFFF) {
skip = true;
} else { /* uni != index , uni != 0xFFFF */
u16 col_index = get_col_index(index);
if (!upcase_table[col_index]) {
upcase_table[col_index] = kmalloc((UTBL_ROW_COUNT * sizeof(u16)), GFP_KERNEL);
if (!upcase_table[col_index]) {
EMSG("failed to allocate memory for "
"new column 0x%x\n", col_index);
ret = -ENOMEM;
goto error;
}
for (j = 0; j < UTBL_ROW_COUNT; j++)
upcase_table[col_index][j] = (col_index << LOW_INDEX_BIT) | j;
}
upcase_table[col_index][get_row_index(index)] = uni;
index++;
}
}
if (index >= 0xFFFF)
return 0;
error:
/* FATAL error: default upcase table has error */
free_upcase_table(sb);
return ret;
}
static s32 load_upcase_table(struct super_block *sb)
{
s32 i, ret;
u32 tbl_clu, type;
u64 sector, tbl_size, num_sectors;
u8 blksize_bits = sb->s_blocksize_bits;
CHAIN_T clu;
CASE_DENTRY_T *ep;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
clu.dir = fsi->root_dir;
clu.flags = 0x01;
if (fsi->vol_type != EXFAT)
goto load_default;
while (!IS_CLUS_EOF(clu.dir)) {
for (i = 0; i < fsi->dentries_per_clu; i++) {
ep = (CASE_DENTRY_T *) get_dentry_in_dir(sb, &clu, i, NULL);
if (!ep)
return -EIO;
type = fsi->fs_func->get_entry_type((DENTRY_T *) ep);
if (type == TYPE_UNUSED)
break;
if (type != TYPE_UPCASE)
continue;
tbl_clu = le32_to_cpu(ep->start_clu);
tbl_size = le64_to_cpu(ep->size);
sector = CLUS_TO_SECT(fsi, tbl_clu);
num_sectors = ((tbl_size - 1) >> blksize_bits) + 1;
ret = __load_upcase_table(sb, sector, num_sectors,
le32_to_cpu(ep->checksum));
if (ret && (ret != -EIO))
goto load_default;
/* load successfully */
return ret;
}
if (get_next_clus_safe(sb, &(clu.dir)))
return -EIO;
}
load_default:
sdfat_log_msg(sb, KERN_INFO, "trying to load default upcase table");
/* load default upcase table */
return __load_default_upcase_table(sb);
} /* end of load_upcase_table */
/*
* Directory Entry Management Functions
*/
s32 walk_fat_chain(struct super_block *sb, CHAIN_T *p_dir, u32 byte_offset, u32 *clu)
{
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
u32 clu_offset;
u32 cur_clu;
clu_offset = byte_offset >> fsi->cluster_size_bits;
cur_clu = p_dir->dir;
if (p_dir->flags == 0x03) {
cur_clu += clu_offset;
} else {
while (clu_offset > 0) {
if (get_next_clus_safe(sb, &cur_clu))
return -EIO;
if (IS_CLUS_EOF(cur_clu)) {
sdfat_fs_error(sb, "invalid dentry access "
"beyond EOF (clu : %u, eidx : %d)",
p_dir->dir,
byte_offset >> DENTRY_SIZE_BITS);
return -EIO;
}
clu_offset--;
}
}
if (clu)
*clu = cur_clu;
return 0;
}
static s32 find_location(struct super_block *sb, CHAIN_T *p_dir, s32 entry, u64 *sector, s32 *offset)
{
s32 ret;
u32 off, clu = 0;
u32 blksize_mask = (u32)(sb->s_blocksize-1);
u8 blksize_bits = sb->s_blocksize_bits;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
off = entry << DENTRY_SIZE_BITS;
/* FAT16 root_dir */
if (IS_CLUS_FREE(p_dir->dir)) {
*offset = off & blksize_mask;
*sector = off >> blksize_bits;
*sector += fsi->root_start_sector;
return 0;
}
ret = walk_fat_chain(sb, p_dir, off, &clu);
if (ret)
return ret;
/* byte offset in cluster */
off &= (fsi->cluster_size - 1);
/* byte offset in sector */
*offset = off & blksize_mask;
/* sector offset in cluster */
*sector = off >> blksize_bits;
*sector += CLUS_TO_SECT(fsi, clu);
return 0;
} /* end of find_location */
DENTRY_T *get_dentry_in_dir(struct super_block *sb, CHAIN_T *p_dir, s32 entry, u64 *sector)
{
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
u32 dentries_per_page = PAGE_SIZE >> DENTRY_SIZE_BITS;
s32 off;
u64 sec;
u8 *buf;
if (p_dir->dir == DIR_DELETED) {
EMSG("%s : abnormal access to deleted dentry\n", __func__);
BUG_ON(!fsi->prev_eio);
return NULL;
}
if (find_location(sb, p_dir, entry, &sec, &off))
return NULL;
/* DIRECTORY READAHEAD :
* Try to read ahead per a page except root directory of fat12/16
*/
if ((!IS_CLUS_FREE(p_dir->dir)) &&
!(entry & (dentries_per_page - 1)))
dcache_readahead(sb, sec);
buf = dcache_getblk(sb, sec);
if (!buf)
return NULL;
if (sector)
*sector = sec;
return (DENTRY_T *)(buf + off);
} /* end of get_dentry_in_dir */
/* used only in search empty_slot() */
#define CNT_UNUSED_NOHIT (-1)
#define CNT_UNUSED_HIT (-2)
/* search EMPTY CONTINUOUS "num_entries" entries */
static s32 search_empty_slot(struct super_block *sb, HINT_FEMP_T *hint_femp, CHAIN_T *p_dir, s32 num_entries)
{
s32 i, dentry, num_empty = 0;
s32 dentries_per_clu;
u32 type;
CHAIN_T clu;
DENTRY_T *ep;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
if (IS_CLUS_FREE(p_dir->dir)) /* FAT16 root_dir */
dentries_per_clu = fsi->dentries_in_root;
else
dentries_per_clu = fsi->dentries_per_clu;
ASSERT(-1 <= hint_femp->eidx);
if (hint_femp->eidx != -1) {
clu.dir = hint_femp->cur.dir;
clu.size = hint_femp->cur.size;
clu.flags = hint_femp->cur.flags;
dentry = hint_femp->eidx;
if (num_entries <= hint_femp->count) {
MMSG("%s: empty slot(HIT) - found "
"(clu : 0x%08x eidx : %d)\n",
__func__, hint_femp->cur.dir, hint_femp->eidx);
hint_femp->eidx = -1;
if (fsi->vol_type == EXFAT)
return dentry;
return dentry + (num_entries - 1);
}
MMSG("%s: empty slot(HIT) - search from "
"(clu : 0x%08x eidx : %d)\n",
__func__, hint_femp->cur.dir, hint_femp->eidx);
} else {
MMSG("%s: empty slot(MISS) - search from "
"(clu:0x%08x eidx : 0)\n",
__func__, p_dir->dir);
clu.dir = p_dir->dir;
clu.size = p_dir->size;
clu.flags = p_dir->flags;
dentry = 0;
}
while (!IS_CLUS_EOF(clu.dir)) {
/* FAT16 root_dir */
if (IS_CLUS_FREE(p_dir->dir))
i = dentry % dentries_per_clu;
else
i = dentry & (dentries_per_clu-1);
for ( ; i < dentries_per_clu; i++, dentry++) {
ep = get_dentry_in_dir(sb, &clu, i, NULL);
if (!ep)
return -EIO;
type = fsi->fs_func->get_entry_type(ep);
if ((type == TYPE_UNUSED) || (type == TYPE_DELETED)) {
num_empty++;
if (hint_femp->eidx == -1) {
hint_femp->eidx = dentry;
hint_femp->count = CNT_UNUSED_NOHIT;
hint_femp->cur.dir = clu.dir;
hint_femp->cur.size = clu.size;
hint_femp->cur.flags = clu.flags;
}
if ((type == TYPE_UNUSED) &&
(hint_femp->count != CNT_UNUSED_HIT)) {
hint_femp->count = CNT_UNUSED_HIT;
}
} else {
if ((hint_femp->eidx != -1) &&
(hint_femp->count == CNT_UNUSED_HIT)) {
/* unused empty group means
* an empty group which includes
* unused dentry
*/
sdfat_fs_error(sb,
"found bogus dentry(%d) "
"beyond unused empty group(%d) "
"(start_clu : %u, cur_clu : %u)",
dentry, hint_femp->eidx, p_dir->dir,
clu.dir);
return -EIO;
}
num_empty = 0;
hint_femp->eidx = -1;
}
if (num_empty >= num_entries) {
/* found and invalidate hint_femp */
hint_femp->eidx = -1;
if (fsi->vol_type == EXFAT)
return (dentry - (num_entries-1));
return dentry;
}
}
if (IS_CLUS_FREE(p_dir->dir))
break; /* FAT16 root_dir */
if (clu.flags == 0x03) {
if ((--clu.size) > 0)
clu.dir++;
else
clu.dir = CLUS_EOF;
} else {
if (get_next_clus_safe(sb, &(clu.dir)))
return -EIO;
}
}
return -ENOSPC;
} /* end of search_empty_slot */
/* find empty directory entry.
* if there isn't any empty slot, expand cluster chain.
*/
static s32 find_empty_entry(struct inode *inode, CHAIN_T *p_dir, s32 num_entries)
{
s32 dentry;
u32 ret, last_clu;
u64 sector;
u64 size = 0;
CHAIN_T clu;
DENTRY_T *ep = NULL;
struct super_block *sb = inode->i_sb;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
FILE_ID_T *fid = &(SDFAT_I(inode)->fid);
HINT_FEMP_T hint_femp;
hint_femp.eidx = -1;
ASSERT(-1 <= fid->hint_femp.eidx);
if (fid->hint_femp.eidx != -1) {
memcpy(&hint_femp, &fid->hint_femp, sizeof(HINT_FEMP_T));
fid->hint_femp.eidx = -1;
}
/* FAT16 root_dir */
if (IS_CLUS_FREE(p_dir->dir))
return search_empty_slot(sb, &hint_femp, p_dir, num_entries);
while ((dentry = search_empty_slot(sb, &hint_femp, p_dir, num_entries)) < 0) {
if (dentry == -EIO)
break;
if (fsi->fs_func->check_max_dentries(fid))
return -ENOSPC;
/* we trust p_dir->size regardless of FAT type */
if (__find_last_cluster(sb, p_dir, &last_clu))
return -EIO;
/*
* Allocate new cluster to this directory
*/
clu.dir = last_clu + 1;
clu.size = 0; /* UNUSED */
clu.flags = p_dir->flags;
/* (0) check if there are reserved clusters
* (create_dir 의 주석 참고)
*/
if (!IS_CLUS_EOF(fsi->used_clusters) &&
((fsi->used_clusters + fsi->reserved_clusters) >= (fsi->num_clusters - 2)))
return -ENOSPC;
/* (1) allocate a cluster */
ret = fsi->fs_func->alloc_cluster(sb, 1, &clu, ALLOC_HOT);
if (ret)
return ret;
if (__clear_cluster(inode, clu.dir))
return -EIO;
/* (2) append to the FAT chain */
if (clu.flags != p_dir->flags) {
/* no-fat-chain bit is disabled,
* so fat-chain should be synced with alloc-bmp
*/
chain_cont_cluster(sb, p_dir->dir, p_dir->size);
p_dir->flags = 0x01;
hint_femp.cur.flags = 0x01;
}
if (clu.flags == 0x01)
if (fat_ent_set(sb, last_clu, clu.dir))
return -EIO;
if (hint_femp.eidx == -1) {
/* the special case that new dentry
* should be allocated from the start of new cluster
*/
hint_femp.eidx = (s32)(p_dir->size <<
(fsi->cluster_size_bits - DENTRY_SIZE_BITS));
hint_femp.count = fsi->dentries_per_clu;
hint_femp.cur.dir = clu.dir;
hint_femp.cur.size = 0;
hint_femp.cur.flags = clu.flags;
}
hint_femp.cur.size++;
p_dir->size++;
size = (p_dir->size << fsi->cluster_size_bits);
/* (3) update the directory entry */
if ((fsi->vol_type == EXFAT) && (p_dir->dir != fsi->root_dir)) {
ep = get_dentry_in_dir(sb,
&(fid->dir), fid->entry+1, §or);
if (!ep)
return -EIO;
fsi->fs_func->set_entry_size(ep, size);
fsi->fs_func->set_entry_flag(ep, p_dir->flags);
if (dcache_modify(sb, sector))
return -EIO;
if (update_dir_chksum(sb, &(fid->dir), fid->entry))
return -EIO;
}
/* directory inode should be updated in here */
i_size_write(inode, (loff_t)size);
SDFAT_I(inode)->i_size_ondisk += fsi->cluster_size;
SDFAT_I(inode)->i_size_aligned += fsi->cluster_size;
SDFAT_I(inode)->fid.size = size;
SDFAT_I(inode)->fid.flags = p_dir->flags;
inode->i_blocks += 1 << (fsi->cluster_size_bits - sb->s_blocksize_bits);
}
return dentry;
} /* end of find_empty_entry */
#define SDFAT_MIN_SUBDIR (2)
static const char *dot_name[SDFAT_MIN_SUBDIR] = { DOS_CUR_DIR_NAME, DOS_PAR_DIR_NAME };
static s32 __count_dos_name_entries(struct super_block *sb, CHAIN_T *p_dir, u32 type, u32 *dotcnt)
{
s32 i, count = 0, check_dot = 0;
s32 dentries_per_clu;
u32 entry_type;
CHAIN_T clu;
DENTRY_T *ep;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
if (IS_CLUS_FREE(p_dir->dir)) /* FAT16 root_dir */
dentries_per_clu = fsi->dentries_in_root;
else
dentries_per_clu = fsi->dentries_per_clu;
clu.dir = p_dir->dir;
clu.size = p_dir->size;
clu.flags = p_dir->flags;
if (dotcnt) {
*dotcnt = 0;
if (fsi->vol_type != EXFAT)
check_dot = 1;
}
while (!IS_CLUS_EOF(clu.dir)) {
for (i = 0; i < dentries_per_clu; i++) {
ep = get_dentry_in_dir(sb, &clu, i, NULL);
if (!ep)
return -EIO;
entry_type = fsi->fs_func->get_entry_type(ep);
if (entry_type == TYPE_UNUSED)
return count;
if (!(type & TYPE_CRITICAL_PRI) && !(type & TYPE_BENIGN_PRI))
continue;
if ((type != TYPE_ALL) && (type != entry_type))
continue;
count++;
if (check_dot && (i < SDFAT_MIN_SUBDIR)) {
BUG_ON(fsi->vol_type == EXFAT);
/* 11 is DOS_NAME_LENGTH */
if (!strncmp(ep->dummy, dot_name[i], 11))
(*dotcnt)++;
}
}
/* FAT16 root_dir */
if (IS_CLUS_FREE(p_dir->dir))
break;
if (clu.flags == 0x03) {
if ((--clu.size) > 0)
clu.dir++;
else
clu.dir = CLUS_EOF;
} else {
if (get_next_clus_safe(sb, &(clu.dir)))
return -EIO;
}
check_dot = 0;
}
return count;
}
s32 check_dir_empty(struct super_block *sb, CHAIN_T *p_dir)
{
s32 i, count = 0;
s32 dentries_per_clu;
u32 type;
CHAIN_T clu;
DENTRY_T *ep;
FS_INFO_T *fsi = &(SDFAT_SB(sb)->fsi);
if (IS_CLUS_FREE(p_dir->dir)) /* FAT16 root_dir */
dentries_per_clu = fsi->dentries_in_root;
else
dentries_per_clu = fsi->dentries_per_clu;