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dir.c
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/*
* linux/fs/fat/dir.c
*
* directory handling functions for fat-based filesystems
*
* Written 1992,1993 by Werner Almesberger
*
* Hidden files 1995 by Albert Cahalan <[email protected]> <[email protected]>
*
* VFAT extensions by Gordon Chaffee <[email protected]>
* Merged with msdos fs by Henrik Storner <[email protected]>
* Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
* Short name translation 1999, 2001 by Wolfram Pienkoss <[email protected]>
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/msdos_fs.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/compat.h>
#include <asm/uaccess.h>
static inline loff_t fat_make_i_pos(struct super_block *sb,
struct buffer_head *bh,
struct msdos_dir_entry *de)
{
return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
| (de - (struct msdos_dir_entry *)bh->b_data);
}
static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
sector_t phys)
{
struct super_block *sb = dir->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh;
int sec;
/* This is not a first sector of cluster, or sec_per_clus == 1 */
if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
return;
/* root dir of FAT12/FAT16 */
if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
return;
bh = sb_find_get_block(sb, phys);
if (bh == NULL || !buffer_uptodate(bh)) {
for (sec = 0; sec < sbi->sec_per_clus; sec++)
sb_breadahead(sb, phys + sec);
}
brelse(bh);
}
/* Returns the inode number of the directory entry at offset pos. If bh is
non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
returned in bh.
AV. Most often we do it item-by-item. Makes sense to optimize.
AV. OK, there we go: if both bh and de are non-NULL we assume that we just
AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
AV. It's done in fat_get_entry() (inlined), here the slow case lives.
AV. Additionally, when we return -1 (i.e. reached the end of directory)
AV. we make bh NULL.
*/
static int fat__get_entry(struct inode *dir, loff_t *pos,
struct buffer_head **bh, struct msdos_dir_entry **de)
{
struct super_block *sb = dir->i_sb;
sector_t phys, iblock;
unsigned long mapped_blocks;
int err, offset;
next:
if (*bh)
brelse(*bh);
*bh = NULL;
iblock = *pos >> sb->s_blocksize_bits;
err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
if (err || !phys)
return -1; /* beyond EOF or error */
fat_dir_readahead(dir, iblock, phys);
*bh = sb_bread(sb, phys);
if (*bh == NULL) {
printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
(unsigned long long)phys);
/* skip this block */
*pos = (iblock + 1) << sb->s_blocksize_bits;
goto next;
}
offset = *pos & (sb->s_blocksize - 1);
*pos += sizeof(struct msdos_dir_entry);
*de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
return 0;
}
static inline int fat_get_entry(struct inode *dir, loff_t *pos,
struct buffer_head **bh,
struct msdos_dir_entry **de)
{
/* Fast stuff first */
if (*bh && *de &&
(*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
*pos += sizeof(struct msdos_dir_entry);
(*de)++;
return 0;
}
return fat__get_entry(dir, pos, bh, de);
}
/*
* Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
* If uni_xlate is enabled and we can't get a 1:1 conversion, use a
* colon as an escape character since it is normally invalid on the vfat
* filesystem. The following four characters are the hexadecimal digits
* of Unicode value. This lets us do a full dump and restore of Unicode
* filenames. We could get into some trouble with long Unicode names,
* but ignore that right now.
* Ahem... Stack smashing in ring 0 isn't fun. Fixed.
*/
static int uni16_to_x8(unsigned char *ascii, const wchar_t *uni, int len,
int uni_xlate, struct nls_table *nls)
{
const wchar_t *ip;
wchar_t ec;
unsigned char *op, nc;
int charlen;
int k;
ip = uni;
op = ascii;
while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
ec = *ip++;
if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
op += charlen;
len -= charlen;
} else {
if (uni_xlate == 1) {
*op = ':';
for (k = 4; k > 0; k--) {
nc = ec & 0xF;
op[k] = nc > 9 ? nc + ('a' - 10)
: nc + '0';
ec >>= 4;
}
op += 5;
len -= 5;
} else {
*op++ = '?';
len--;
}
}
}
if (unlikely(*ip)) {
printk(KERN_WARNING "FAT: filename was truncated while "
"converting.");
}
*op = 0;
return (op - ascii);
}
static inline int fat_uni_to_x8(struct msdos_sb_info *sbi, const wchar_t *uni,
unsigned char *buf, int size)
{
if (sbi->options.utf8)
return utf8_wcstombs(buf, uni, size);
else
return uni16_to_x8(buf, uni, size, sbi->options.unicode_xlate,
sbi->nls_io);
}
static inline int
fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
{
int charlen;
charlen = t->char2uni(c, clen, uni);
if (charlen < 0) {
*uni = 0x003f; /* a question mark */
charlen = 1;
}
return charlen;
}
static inline int
fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
{
int charlen;
wchar_t wc;
charlen = t->char2uni(c, clen, &wc);
if (charlen < 0) {
*uni = 0x003f; /* a question mark */
charlen = 1;
} else if (charlen <= 1) {
unsigned char nc = t->charset2lower[*c];
if (!nc)
nc = *c;
if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
*uni = 0x003f; /* a question mark */
charlen = 1;
}
} else
*uni = wc;
return charlen;
}
static inline int
fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
wchar_t *uni_buf, unsigned short opt, int lower)
{
int len = 0;
if (opt & VFAT_SFN_DISPLAY_LOWER)
len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
else if (opt & VFAT_SFN_DISPLAY_WIN95)
len = fat_short2uni(nls, buf, buf_size, uni_buf);
else if (opt & VFAT_SFN_DISPLAY_WINNT) {
if (lower)
len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
else
len = fat_short2uni(nls, buf, buf_size, uni_buf);
} else
len = fat_short2uni(nls, buf, buf_size, uni_buf);
return len;
}
static inline int fat_name_match(struct msdos_sb_info *sbi,
const unsigned char *a, int a_len,
const unsigned char *b, int b_len)
{
if (a_len != b_len)
return 0;
if (sbi->options.name_check != 's')
return !nls_strnicmp(sbi->nls_io, a, b, a_len);
else
return !memcmp(a, b, a_len);
}
enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
/**
* fat_parse_long - Parse extended directory entry.
*
* This function returns zero on success, negative value on error, or one of
* the following:
*
* %PARSE_INVALID - Directory entry is invalid.
* %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
* %PARSE_EOF - Directory has no more entries.
*/
static int fat_parse_long(struct inode *dir, loff_t *pos,
struct buffer_head **bh, struct msdos_dir_entry **de,
wchar_t **unicode, unsigned char *nr_slots)
{
struct msdos_dir_slot *ds;
unsigned char id, slot, slots, alias_checksum;
if (!*unicode) {
*unicode = __getname();
if (!*unicode) {
brelse(*bh);
return -ENOMEM;
}
}
parse_long:
slots = 0;
ds = (struct msdos_dir_slot *)*de;
id = ds->id;
if (!(id & 0x40))
return PARSE_INVALID;
slots = id & ~0x40;
if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
return PARSE_INVALID;
*nr_slots = slots;
alias_checksum = ds->alias_checksum;
slot = slots;
while (1) {
int offset;
slot--;
offset = slot * 13;
fat16_towchar(*unicode + offset, ds->name0_4, 5);
fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
if (ds->id & 0x40)
(*unicode)[offset + 13] = 0;
if (fat_get_entry(dir, pos, bh, de) < 0)
return PARSE_EOF;
if (slot == 0)
break;
ds = (struct msdos_dir_slot *)*de;
if (ds->attr != ATTR_EXT)
return PARSE_NOT_LONGNAME;
if ((ds->id & ~0x40) != slot)
goto parse_long;
if (ds->alias_checksum != alias_checksum)
goto parse_long;
}
if ((*de)->name[0] == DELETED_FLAG)
return PARSE_INVALID;
if ((*de)->attr == ATTR_EXT)
goto parse_long;
if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
return PARSE_INVALID;
if (fat_checksum((*de)->name) != alias_checksum)
*nr_slots = 0;
return 0;
}
/*
* Return values: negative -> error, 0 -> not found, positive -> found,
* value is the total amount of slots, including the shortname entry.
*/
int fat_search_long(struct inode *inode, const unsigned char *name,
int name_len, struct fat_slot_info *sinfo)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh = NULL;
struct msdos_dir_entry *de;
struct nls_table *nls_disk = sbi->nls_disk;
unsigned char nr_slots;
wchar_t bufuname[14];
wchar_t *unicode = NULL;
unsigned char work[MSDOS_NAME];
unsigned char *bufname = NULL;
unsigned short opt_shortname = sbi->options.shortname;
loff_t cpos = 0;
int chl, i, j, last_u, err, len;
bufname = __getname();
if (!bufname)
return -ENOMEM;
err = -ENOENT;
while (1) {
if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
goto end_of_dir;
parse_record:
nr_slots = 0;
if (de->name[0] == DELETED_FLAG)
continue;
if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
continue;
if (de->attr != ATTR_EXT && IS_FREE(de->name))
continue;
if (de->attr == ATTR_EXT) {
int status = fat_parse_long(inode, &cpos, &bh, &de,
&unicode, &nr_slots);
if (status < 0)
return status;
else if (status == PARSE_INVALID)
continue;
else if (status == PARSE_NOT_LONGNAME)
goto parse_record;
else if (status == PARSE_EOF)
goto end_of_dir;
}
memcpy(work, de->name, sizeof(de->name));
/* see namei.c, msdos_format_name */
if (work[0] == 0x05)
work[0] = 0xE5;
for (i = 0, j = 0, last_u = 0; i < 8;) {
if (!work[i])
break;
chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_BASE);
if (chl <= 1) {
if (work[i] != ' ')
last_u = j;
} else {
last_u = j;
}
i += chl;
}
j = last_u;
fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
for (i = 8; i < MSDOS_NAME;) {
if (!work[i])
break;
chl = fat_shortname2uni(nls_disk, &work[i],
MSDOS_NAME - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_EXT);
if (chl <= 1) {
if (work[i] != ' ')
last_u = j;
} else {
last_u = j;
}
i += chl;
}
if (!last_u)
continue;
/* Compare shortname */
bufuname[last_u] = 0x0000;
len = fat_uni_to_x8(sbi, bufuname, bufname, PATH_MAX);
if (fat_name_match(sbi, name, name_len, bufname, len))
goto found;
if (nr_slots) {
/* Compare longname */
len = fat_uni_to_x8(sbi, unicode, bufname, PATH_MAX);
if (fat_name_match(sbi, name, name_len, bufname, len))
goto found;
}
}
found:
nr_slots++; /* include the de */
sinfo->slot_off = cpos - nr_slots * sizeof(*de);
sinfo->nr_slots = nr_slots;
sinfo->de = de;
sinfo->bh = bh;
sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
err = 0;
end_of_dir:
if (bufname)
__putname(bufname);
if (unicode)
__putname(unicode);
return err;
}
EXPORT_SYMBOL_GPL(fat_search_long);
struct fat_ioctl_filldir_callback {
void __user *dirent;
int result;
/* for dir ioctl */
const char *longname;
int long_len;
const char *shortname;
int short_len;
};
static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
filldir_t filldir, int short_only, int both)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh;
struct msdos_dir_entry *de;
struct nls_table *nls_disk = sbi->nls_disk;
unsigned char nr_slots;
wchar_t bufuname[14];
wchar_t *unicode = NULL;
unsigned char c, work[MSDOS_NAME], bufname[56], *ptname = bufname;
unsigned short opt_shortname = sbi->options.shortname;
int isvfat = sbi->options.isvfat;
int nocase = sbi->options.nocase;
const char *fill_name;
unsigned long inum;
unsigned long lpos, dummy, *furrfu = &lpos;
loff_t cpos;
int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len;
int ret = 0;
lock_super(sb);
cpos = filp->f_pos;
/* Fake . and .. for the root directory. */
if (inode->i_ino == MSDOS_ROOT_INO) {
while (cpos < 2) {
if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
goto out;
cpos++;
filp->f_pos++;
}
if (cpos == 2) {
dummy = 2;
furrfu = &dummy;
cpos = 0;
}
}
if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
ret = -ENOENT;
goto out;
}
bh = NULL;
get_new:
if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
goto end_of_dir;
parse_record:
nr_slots = 0;
/* Check for long filename entry */
if (isvfat) {
if (de->name[0] == DELETED_FLAG)
goto record_end;
if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
goto record_end;
if (de->attr != ATTR_EXT && IS_FREE(de->name))
goto record_end;
} else {
if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
goto record_end;
}
if (isvfat && de->attr == ATTR_EXT) {
int status = fat_parse_long(inode, &cpos, &bh, &de,
&unicode, &nr_slots);
if (status < 0) {
filp->f_pos = cpos;
ret = status;
goto out;
} else if (status == PARSE_INVALID)
goto record_end;
else if (status == PARSE_NOT_LONGNAME)
goto parse_record;
else if (status == PARSE_EOF)
goto end_of_dir;
}
if (sbi->options.dotsOK) {
ptname = bufname;
dotoffset = 0;
if (de->attr & ATTR_HIDDEN) {
*ptname++ = '.';
dotoffset = 1;
}
}
memcpy(work, de->name, sizeof(de->name));
/* see namei.c, msdos_format_name */
if (work[0] == 0x05)
work[0] = 0xE5;
for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
if (!(c = work[i]))
break;
chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_BASE);
if (chl <= 1) {
ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
if (c != ' ') {
last = i;
last_u = j;
}
} else {
last_u = j;
for (chi = 0; chi < chl && i < 8; chi++) {
ptname[i] = work[i];
i++; last = i;
}
}
}
i = last;
j = last_u;
fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
ptname[i++] = '.';
for (i2 = 8; i2 < MSDOS_NAME;) {
if (!(c = work[i2]))
break;
chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_EXT);
if (chl <= 1) {
i2++;
ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
if (c != ' ') {
last = i;
last_u = j;
}
} else {
last_u = j;
for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) {
ptname[i++] = work[i2++];
last = i;
}
}
}
if (!last)
goto record_end;
i = last + dotoffset;
j = last_u;
lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
inum = inode->i_ino;
else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
inum = parent_ino(filp->f_path.dentry);
} else {
loff_t i_pos = fat_make_i_pos(sb, bh, de);
struct inode *tmp = fat_iget(sb, i_pos);
if (tmp) {
inum = tmp->i_ino;
iput(tmp);
} else
inum = iunique(sb, MSDOS_ROOT_INO);
}
if (isvfat) {
bufuname[j] = 0x0000;
i = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
}
fill_name = bufname;
fill_len = i;
if (!short_only && nr_slots) {
/* convert the unicode long name. 261 is maximum size
* of unicode buffer. (13 * slots + nul) */
void *longname = unicode + 261;
int buf_size = PATH_MAX - (261 * sizeof(unicode[0]));
int long_len = fat_uni_to_x8(sbi, unicode, longname, buf_size);
if (!both) {
fill_name = longname;
fill_len = long_len;
} else {
/* hack for fat_ioctl_filldir() */
struct fat_ioctl_filldir_callback *p = dirent;
p->longname = longname;
p->long_len = long_len;
p->shortname = bufname;
p->short_len = i;
fill_name = NULL;
fill_len = 0;
}
}
if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
(de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
goto fill_failed;
record_end:
furrfu = &lpos;
filp->f_pos = cpos;
goto get_new;
end_of_dir:
filp->f_pos = cpos;
fill_failed:
brelse(bh);
if (unicode)
__putname(unicode);
out:
unlock_super(sb);
return ret;
}
static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode *inode = filp->f_path.dentry->d_inode;
return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
}
#define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
static int func(void *__buf, const char *name, int name_len, \
loff_t offset, u64 ino, unsigned int d_type) \
{ \
struct fat_ioctl_filldir_callback *buf = __buf; \
struct dirent_type __user *d1 = buf->dirent; \
struct dirent_type __user *d2 = d1 + 1; \
\
if (buf->result) \
return -EINVAL; \
buf->result++; \
\
if (name != NULL) { \
/* dirent has only short name */ \
if (name_len >= sizeof(d1->d_name)) \
name_len = sizeof(d1->d_name) - 1; \
\
if (put_user(0, d2->d_name) || \
put_user(0, &d2->d_reclen) || \
copy_to_user(d1->d_name, name, name_len) || \
put_user(0, d1->d_name + name_len) || \
put_user(name_len, &d1->d_reclen)) \
goto efault; \
} else { \
/* dirent has short and long name */ \
const char *longname = buf->longname; \
int long_len = buf->long_len; \
const char *shortname = buf->shortname; \
int short_len = buf->short_len; \
\
if (long_len >= sizeof(d1->d_name)) \
long_len = sizeof(d1->d_name) - 1; \
if (short_len >= sizeof(d1->d_name)) \
short_len = sizeof(d1->d_name) - 1; \
\
if (copy_to_user(d2->d_name, longname, long_len) || \
put_user(0, d2->d_name + long_len) || \
put_user(long_len, &d2->d_reclen) || \
put_user(ino, &d2->d_ino) || \
put_user(offset, &d2->d_off) || \
copy_to_user(d1->d_name, shortname, short_len) || \
put_user(0, d1->d_name + short_len) || \
put_user(short_len, &d1->d_reclen)) \
goto efault; \
} \
return 0; \
efault: \
buf->result = -EFAULT; \
return -EFAULT; \
}
FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
void __user *dirent, filldir_t filldir,
int short_only, int both)
{
struct fat_ioctl_filldir_callback buf;
int ret;
buf.dirent = dirent;
buf.result = 0;
mutex_lock(&inode->i_mutex);
ret = -ENOENT;
if (!IS_DEADDIR(inode)) {
ret = __fat_readdir(inode, filp, &buf, filldir,
short_only, both);
}
mutex_unlock(&inode->i_mutex);
if (ret >= 0)
ret = buf.result;
return ret;
}
static int fat_dir_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
int short_only, both;
switch (cmd) {
case VFAT_IOCTL_READDIR_SHORT:
short_only = 1;
both = 0;
break;
case VFAT_IOCTL_READDIR_BOTH:
short_only = 0;
both = 1;
break;
default:
return fat_generic_ioctl(inode, filp, cmd, arg);
}
if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
return -EFAULT;
/*
* Yes, we don't need this put_user() absolutely. However old
* code didn't return the right value. So, app use this value,
* in order to check whether it is EOF.
*/
if (put_user(0, &d1->d_reclen))
return -EFAULT;
return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
short_only, both);
}
#ifdef CONFIG_COMPAT
#define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
#define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
unsigned long arg)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct compat_dirent __user *d1 = compat_ptr(arg);
int short_only, both;
switch (cmd) {
case VFAT_IOCTL_READDIR_SHORT32:
short_only = 1;
both = 0;
break;
case VFAT_IOCTL_READDIR_BOTH32:
short_only = 0;
both = 1;
break;
default:
return -ENOIOCTLCMD;
}
if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
return -EFAULT;
/*
* Yes, we don't need this put_user() absolutely. However old
* code didn't return the right value. So, app use this value,
* in order to check whether it is EOF.
*/
if (put_user(0, &d1->d_reclen))
return -EFAULT;
return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
short_only, both);
}
#endif /* CONFIG_COMPAT */
const struct file_operations fat_dir_operations = {
.read = generic_read_dir,
.readdir = fat_readdir,
.ioctl = fat_dir_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = fat_compat_dir_ioctl,
#endif
.fsync = file_fsync,
};
static int fat_get_short_entry(struct inode *dir, loff_t *pos,
struct buffer_head **bh,
struct msdos_dir_entry **de)
{
while (fat_get_entry(dir, pos, bh, de) >= 0) {
/* free entry or long name entry or volume label */
if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
return 0;
}
return -ENOENT;
}
/*
* The ".." entry can not provide the "struct fat_slot_info" informations
* for inode. So, this function provide the some informations only.
*/
int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
struct msdos_dir_entry **de, loff_t *i_pos)
{
loff_t offset;
offset = 0;
*bh = NULL;
while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
*i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
return 0;
}
}
return -ENOENT;
}
EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
/* See if directory is empty */
int fat_dir_empty(struct inode *dir)
{
struct buffer_head *bh;
struct msdos_dir_entry *de;
loff_t cpos;
int result = 0;
bh = NULL;
cpos = 0;
while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
result = -ENOTEMPTY;
break;
}
}
brelse(bh);
return result;
}
EXPORT_SYMBOL_GPL(fat_dir_empty);
/*
* fat_subdirs counts the number of sub-directories of dir. It can be run
* on directories being created.
*/
int fat_subdirs(struct inode *dir)
{
struct buffer_head *bh;
struct msdos_dir_entry *de;
loff_t cpos;
int count = 0;
bh = NULL;
cpos = 0;
while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
if (de->attr & ATTR_DIR)
count++;
}
brelse(bh);
return count;
}
/*
* Scans a directory for a given file (name points to its formatted name).
* Returns an error code or zero.
*/
int fat_scan(struct inode *dir, const unsigned char *name,
struct fat_slot_info *sinfo)
{
struct super_block *sb = dir->i_sb;
sinfo->slot_off = 0;
sinfo->bh = NULL;
while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
&sinfo->de) >= 0) {
if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
sinfo->slot_off -= sizeof(*sinfo->de);
sinfo->nr_slots = 1;
sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
return 0;
}
}
return -ENOENT;
}
EXPORT_SYMBOL_GPL(fat_scan);
static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
{
struct super_block *sb = dir->i_sb;
struct buffer_head *bh;
struct msdos_dir_entry *de, *endp;
int err = 0, orig_slots;
while (nr_slots) {
bh = NULL;
if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
err = -EIO;
break;
}
orig_slots = nr_slots;
endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
while (nr_slots && de < endp) {
de->name[0] = DELETED_FLAG;
de++;
nr_slots--;
}
mark_buffer_dirty(bh);
if (IS_DIRSYNC(dir))
err = sync_dirty_buffer(bh);
brelse(bh);
if (err)
break;
/* pos is *next* de's position, so this does `- sizeof(de)' */
pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
}
return err;
}
int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
{
struct msdos_dir_entry *de;
struct buffer_head *bh;
int err = 0, nr_slots;
/*
* First stage: Remove the shortname. By this, the directory
* entry is removed.
*/
nr_slots = sinfo->nr_slots;
de = sinfo->de;
sinfo->de = NULL;
bh = sinfo->bh;
sinfo->bh = NULL;
while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
de->name[0] = DELETED_FLAG;
de--;
nr_slots--;
}
mark_buffer_dirty(bh);
if (IS_DIRSYNC(dir))
err = sync_dirty_buffer(bh);
brelse(bh);
if (err)
return err;
dir->i_version++;
if (nr_slots) {
/*
* Second stage: remove the remaining longname slots.
* (This directory entry is already removed, and so return
* the success)
*/
err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
if (err) {