/*
* linux/fs/vfat/namei.c
*
* Written 1992,1993 by Werner Almesberger
*
* Windows95/Windows NT compatible extended MSDOS filesystem
* by Gordon Chaffee Copyright (C) 1995. Send bug reports for the
* VFAT filesystem to <chaffee@cs.berkeley.edu>. Specify
* what file operation caused you trouble and if you can duplicate
* the problem, send a script that demonstrates it.
*
* Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
*
* Support Multibyte characters and cleanup by
* OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
*/
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include <linux/namei.h>
#include "fat.h"
/*
* If new entry was created in the parent, it could create the 8.3
* alias (the shortname of logname). So, the parent may have the
* negative-dentry which matches the created 8.3 alias.
*
* If it happened, the negative dentry isn't actually negative
* anymore. So, drop it.
*/
static int vfat_revalidate_shortname(struct dentry *dentry)
{
int ret = 1;
spin_lock(&dentry->d_lock);
if (dentry->d_time != dentry->d_parent->d_inode->i_version)
ret = 0;
spin_unlock(&dentry->d_lock);
return ret;
}
static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
{
/* This is not negative dentry. Always valid. */
if (dentry->d_inode)
return 1;
return vfat_revalidate_shortname(dentry);
}
static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
{
/*
* This is not negative dentry. Always valid.
*
* Note, rename() to existing directory entry will have ->d_inode,
* and will use existing name which isn't specified name by user.
*
* We may be able to drop this positive dentry here. But dropping
* positive dentry isn't good idea. So it's unsupported like
* rename("filename", "FILENAME") for now.
*/
if (dentry->d_inode)
return 1;
/*
* This may be nfsd (or something), anyway, we can't see the
* intent of this. So, since this can be for creation, drop it.
*/
if (!nd)
return 0;
/*
* Drop the negative dentry, in order to make sure to use the
* case sensitive name which is specified by user if this is
* for creation.
*/
if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) {
if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
return 0;
}
return vfat_revalidate_shortname(dentry);
}
/* returns the length of a struct qstr, ignoring trailing dots */
static unsigned int vfat_striptail_len(struct qstr *qstr)
{
unsigned int len = qstr->len;
while (len && qstr->name[len - 1] == '.')
len--;
return len;
}
/*
* Compute the hash for the vfat name corresponding to the dentry.
* Note: if the name is invalid, we leave the hash code unchanged so
* that the existing dentry can be used. The vfat fs routines will
* return ENOENT or EINVAL as appropriate.
*/
static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
{
qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
return 0;
}
/*
* Compute the hash for the vfat name corresponding to the dentry.
* Note: if the name is invalid, we leave the hash code unchanged so
* that the existing dentry can be used. The vfat fs routines will
* return ENOENT or EINVAL as appropriate.
*/
static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
{
struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
const unsigned char *name;
unsigned int len;
unsigned long hash;
name = qstr->name;
len = vfat_striptail_len(qstr);
hash = init_name_hash();
while (len--)
hash = partial_name_hash(nls_tolower(t, *name++), hash);
qstr->hash = end_name_hash(hash);
return 0;
}
/*
* Case insensitive compare of two vfat names.
*/
static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
{
struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
unsigned int alen, blen;
/* A filename cannot end in '.' or we treat it like it has none */
alen = vfat_striptail_len(a);
blen = vfat_striptail_len(b);
if (alen == blen) {
if (nls_strnicmp(t, a->name, b->name, alen) == 0)
return 0;
}
return 1;
}
/*
* Case sensitive compare of two vfat names.
*/
static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
{
unsigned int alen, blen;
/* A filename cannot end in '.' or we treat it like it has none */
alen = vfat_striptail_len(a);
blen = vfat_striptail_len(b);
if (alen == blen) {
if (strncmp(a->name, b->name, alen) == 0)
return 0;
}
return 1;
}
static const struct dentry_operations vfat_ci_dentry_ops = {
.d_revalidate = vfat_revalidate_ci,
.d_hash = vfat_hashi,
.d_compare = vfat_cmpi,
};
static const struct dentry_operations vfat_dentry_ops = {
.d_revalidate = vfat_revalidate,
.d_hash = vfat_hash,
.d_compare = vfat_cmp,
};
/* Characters that are undesirable in an MS-DOS file name */
static inline wchar_t vfat_bad_char(wchar_t w)
{
return (w < 0x0020)
|| (w == '*') || (w == '?') || (w == '<') || (w == '>')
|| (w == '|') || (w == '"') || (w == ':') || (w == '/')
|| (w == '\\');
}
static inline wchar_t vfat_replace_char(wchar_t w)
{
return (w == '[') || (w == ']') || (w == ';') || (w == ',')
|| (w == '+') || (w == '=');
}
static wchar_t vfat_skip_char(wchar_t w)
{
return (w == '.') || (w == ' ');
}
static inline int vfat_is_used_badchars(const wchar_t *s, int len)
{
int i;
for (i = 0; i < len; i++)
if (vfat_bad_char(s[i]))
return -EINVAL;
if (s[i - 1] == ' ') /* last character cannot be space */
return -EINVAL;
return 0;
}
static int vfat_find_form(struct inode *dir, unsigned char *name)
{
struct fat_slot_info sinfo;
int err = fat_scan(dir, name, &sinfo);
if (err)
return -ENOENT;
brelse(sinfo.bh);
return 0;
}
/*
* 1) Valid characters for the 8.3 format alias are any combination of
* letters, uppercase alphabets, digits, any of the
* following special characters:
* $ % ' ` - @ { } ~ ! # ( ) & _ ^
* In this case Longfilename is not stored in disk.
*
* WinNT's Extension:
* File name and extension name is contain uppercase/lowercase
* only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT.
*
* 2) File name is 8.3 format, but it contain the uppercase and
* lowercase char, muliti bytes char, etc. In this case numtail is not
* added, but Longfilename is stored.
*
* 3) When the one except for the above, or the following special
* character are contained:
* . [ ] ; , + =
* numtail is added, and Longfilename must be stored in disk .
*/
struct shortname_info {
unsigned char lower:1,
upper:1,
valid:1;
};
#define INIT_SHORTNAME_INFO(x) do { \
(x)->lower = 1; \
(x)->upper = 1; \
(x)->valid = 1; \
} while (0)
static inline int to_shortname_char(struct nls_table *nls,
unsigned char *buf, int buf_size,
wchar_t *src, struct shortname_info *info)
{
int len;
if (vfat_skip_char(*src)) {
info->valid = 0;
return 0;
}
if (vfat_replace_char(*src)) {
info->valid = 0;
buf[0] = '_';
return 1;
}
len = nls->uni2char(*src, buf, buf_size);
if (len <= 0) {
info->valid = 0;
buf[0] = '_';
len = 1;
} else if (len == 1) {
unsigned char prev = buf[0];
if (buf[0] >= 0x7F) {
info->lower = 0;
info->upper = 0;
}
buf[0] = nls_toupper(nls, buf[0]);
if (isalpha(buf[0])) {
if (buf[0] == prev)
info->lower = 0;
else
info->upper = 0;
}
} else {
info->lower = 0;
info->upper = 0;
}
return len;
}
/*
* Given a valid longname, create a unique shortname. Make sure the
* shortname does not exist
* Returns negative number on error, 0 for a normal
* return, and 1 for valid shortname
*/
static int vfat_create_shortname(struct inode *dir, struct nls_table *nls,
wchar_t *uname, int ulen,
unsigned char *name_res, unsigned char *lcase)
{
struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options;
wchar_t *ip, *ext_start, *end, *name_start;
unsigned char base[9], ext[4], buf[8], *p;
unsigned char charbuf[NLS_MAX_CHARSET_SIZE];
int chl, chi;
int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen;
int is_shortname;
struct shortname_info base_info, ext_info;
is_shortname = 1;
INIT_SHORTNAME_INFO(&base_info);
INIT_SHORTNAME_INFO(&ext_info);
/* Now, we need to create a shortname from the long name */
ext_start = end = &uname[ulen];
while (--ext_start >= uname) {
if (*ext_start == 0x002E) { /* is `.' */
if (ext_start == end - 1) {
sz = ulen;
ext_start = NULL;
}
break;
}
}
if (ext_start == uname - 1) {
sz = ulen;
ext_start = NULL;
} else if (ext_start) {
/*
* Names which start with a dot could be just
* an extension eg. "...test". In this case Win95
* uses the extension as the name and sets no extension.
*/
name_start = &uname[0];
while (name_start < ext_start) {
if (!vfat_skip_char(*name_start))
break;
name_start++;
}
if (name_start != ext_start) {
sz = ext_start - uname;
ext_start++;
} else {
sz = ulen;
ext_start = NULL;
}
}
numtail_baselen = 6;
numtail2_baselen = 2;
for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) {
chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
ip, &base_info);
if (chl == 0)
continue;
if (baselen < 2 && (baselen + chl) > 2)
numtail2_baselen = baselen;
if (baselen < 6 && (baselen + chl) > 6)
numtail_baselen = baselen;
for (chi = 0; chi < chl; chi++) {
*p++ = charbuf[chi];
baselen++;
if (baselen >= 8)
break;
}
if (baselen >= 8) {
if ((chi < chl - 1) || (ip + 1) - uname < sz)
is_shortname = 0;
break;
}
}
if (baselen == 0) {
return -EINVAL;
}
extlen = 0;
if (ext_start) {
for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) {
chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
ip, &ext_info);
if (chl == 0)
continue;
if ((extlen + chl) > 3) {
is_shortname = 0;
break;
}
for (chi = 0; chi < chl; chi++) {
*p++ = charbuf[chi];
extlen++;
}
if (extlen >= 3) {
if (ip + 1 != end)
is_shortname = 0;
break;
}
}
}
ext[extlen] = '\0';
base[baselen] = '\0';
/* Yes, it can happen. ".\xe5" would do it. */
if (base[0] == DELETED_FLAG)
base[0] = 0x05;
/* OK, at this point we know that base is not longer than 8 symbols,
* ext is not longer than 3, base is nonempty, both don't contain
* any bad symbols (lowercase transformed to uppercase).
*/
memset(name_res, ' ', MSDOS_NAME);
memcpy(name_res, base, baselen);
memcpy(name_res + 8, ext, extlen);
*lcase = 0;
if (is_shortname && base_info.valid && ext_info.valid) {
if (vfat_find_form(dir, name_res) == 0)
return -EEXIST;
if (opts->shortname & VFAT_SFN_CREATE_WIN95) {
return (base_info.upper && ext_info.upper);
} else if (opts->shortname & VFAT_SFN_CREATE_WINNT) {
if ((base_info.upper || base_info.lower) &&
(ext_info.upper || ext_info.lower)) {
if (!base_info.upper && base_info.lower)
*lcase |= CASE_LOWER_BASE;
if (!ext_info.upper && ext_info.lower)
*lcase |= CASE_LOWER_EXT;
return 1;
}
return 0;
} else {
BUG();
}
}
if (opts->numtail == 0)
if (vfat_find_form(dir, name_res) < 0)
return 0;
/*
* Try to find a unique extension. This used to
* iterate through all possibilities sequentially,
* but that gave extremely bad performance. Windows
* only tries a few cases before using random
* values for part of the base.
*/
if (baselen > 6) {
baselen = numtail_baselen;
name_res[7] = ' ';
}
name_res[baselen] = '~';
for (i = 1; i < 10; i++) {
name_res[baselen + 1] = i + '0';
if (vfat_find_form(dir, name_res) < 0)
return 0;
}
i = jiffies & 0xffff;
sz = (jiffies >> 16) & 0x7;
if (baselen > 2) {
baselen = numtail2_baselen;
name_res[7] = ' ';
}
name_res[baselen + 4] = '~';
name_res[baselen + 5] = '1' + sz;
while (1) {
sprintf(buf, "%04X", i);
memcpy(&name_res[baselen], buf, 4);
if (vfat_find_form(dir, name_res) < 0)
break;
i -= 11;
}
return 0;
}
/* Translate a string, including coded sequences into Unicode */
static int
xlate_to_uni(const unsigned char *name, int len, unsigned char *outname,
int *longlen, int *outlen, int escape, int utf8,
struct nls_table *nls)
{
const unsigned char *ip;
unsigned char nc;
unsigned char *op;
unsigned int ec;
int i, k, fill;
int charlen;
if (utf8) {
int name_len = strlen(name);
*outlen = utf8s_to_utf16s(name, PATH_MAX, (wchar_t *) outname);
/*
* We stripped '.'s before and set len appropriately,
* but utf8s_to_utf16s doesn't care about len
*/
*outlen -= (name_len - len);
if (*outlen > 255)
return -ENAMETOOLONG;
op = &outname[*outlen * sizeof(wchar_t)];
} else {
if (nls) {
for (i = 0, ip = name, op = outname, *outlen = 0;
i < len && *outlen <= 255;
*outlen += 1)
{
if (escape && (*ip == ':')) {
if (i > len - 5)
return -EINVAL;
ec = 0;
for (k = 1; k < 5; k++) {
nc = ip[k];
ec <<= 4;
if (nc >= '0' && nc <= '9') {
ec |= nc - '0';
continue;
}
if (nc >= 'a' && nc <= 'f') {
ec |= nc - ('a' - 10);
continue;
}
if (nc >= 'A' && nc <= 'F') {
ec |= nc - ('A' - 10);
continue;
}
return -EINVAL;
}
*op++ = ec & 0xFF;
*op++ = ec >> 8;
ip += 5;
i += 5;
} else {
if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0)
return -EINVAL;
ip += charlen;
i += charlen;
op += 2;
}
}
if (i < len)
return -ENAMETOOLONG;
} else {
for (i = 0, ip = name, op = outname, *outlen = 0;
i < len && *outlen <= 255;
i++, *outlen += 1)
{
*op++ = *ip++;
*op++ = 0;
}
if (i < len)
return -ENAMETOOLONG;
}
}
*longlen = *outlen;
if (*outlen % 13) {
*op++ = 0;
*op++ = 0;
*outlen += 1;
if (*outlen % 13) {
fill = 13 - (*outlen % 13);
for (i = 0; i < fill; i++) {
*op++ = 0xff;
*op++ = 0xff;
}
*outlen += fill;
}
}
return 0;
}
static int vfat_build_slots(struct inode *dir, const unsigned char *name,
int len, int is_dir, int cluster,
struct timespec *ts,
struct msdos_dir_slot *slots, int *nr_slots)
{
struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
struct fat_mount_options *opts = &sbi->options;
struct msdos_dir_slot *ps;
struct msdos_dir_entry *de;
unsigned char cksum, lcase;
unsigned char msdos_name[MSDOS_NAME];
wchar_t *uname;
__le16 time, date;
u8 time_cs;
int err, ulen, usize, i;
loff_t offset;
*nr_slots = 0;
uname = __getname();
if (!uname)
return -ENOMEM;
err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize,
opts->unicode_xlate, opts->utf8, sbi->nls_io);
if (err)
goto out_free;
err = vfat_is_used_badchars(uname, ulen);
if (err)
goto out_free;
err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen,
msdos_name, &lcase);
if (err < 0)
goto out_free;
else if (err == 1) {
de = (struct msdos_dir_entry *)slots;
err = 0;
goto shortname;
}
/* build the entry of long file name */
cksum = fat_checksum(msdos_name);
*nr_slots = usize / 13;
for (ps = slots, i = *nr_slots; i > 0; i--, ps++) {
ps->id = i;
ps->attr = ATTR_EXT;
ps->reserved = 0;
ps->alias_checksum = cksum;
ps->start = 0;
offset = (i - 1) * 13;
fatwchar_to16(ps->name0_4, uname + offset, 5);
fatwchar_to16(ps->name5_10, uname + offset + 5, 6);
fatwchar_to16(ps->name11_12, uname + offset + 11, 2);
}
slots[0].id |= 0x40;
de = (struct msdos_dir_entry *)ps;
shortname:
/* build the entry of 8.3 alias name */
(*nr_slots)++;
memcpy(de->name, msdos_name, MSDOS_NAME);
de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
de->lcase = lcase;
fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
de->time = de->ctime = time;
de->date = de->cdate = de->adate = date;
de->ctime_cs = time_cs;
de->start = cpu_to_le16(cluster);
de->starthi = cpu_to_le16(cluster >> 16);
de->size = 0;
out_free:
__putname(uname);
return err;
}
static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir,
int cluster, struct timespec *ts,
struct fat_slot_info *sinfo)
{
struct msdos_dir_slot *slots;
unsigned int len;
int err, nr_slots;
len = vfat_striptail_len(qname);
if (len == 0)
return -ENOENT;
slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS);
if (slots == NULL)
return -ENOMEM;
err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts,
slots, &nr_slots);
if (err)
goto cleanup;
err = fat_add_entries(dir, slots, nr_slots, sinfo);
if (err)
goto cleanup;
/* update timestamp */
dir->i_ctime = dir->i_mtime = dir->i_atime = *ts;
if (IS_DIRSYNC(dir))
(void)fat_sync_inode(dir);
else
mark_inode_dirty(dir);
cleanup:
kfree(slots);
return err;
}
static int vfat_find(struct inode *dir, struct qstr *qname,
struct fat_slot_info *sinfo)
{
unsigned int len = vfat_striptail_len(qname);
if (len == 0)
return -ENOENT;
return fat_search_long(dir, qname->name, len, sinfo);
}
static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct super_block *sb = dir->i_sb;
struct fat_slot_info sinfo;
struct inode *inode;
struct dentry *alias;
int err;
lock_super(sb);
err = vfat_find(dir, &dentry->d_name, &sinfo);
if (err) {
if (err == -ENOENT) {
inode = NULL;
goto out;
}
goto error;
}
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
brelse(sinfo.bh);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto error;
}
alias = d_find_alias(inode);
if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
/*
* This inode has non DCACHE_DISCONNECTED dentry. This
* means, the user did ->lookup() by an another name
* (longname vs 8.3 alias of it) in past.
*
* Switch to new one for reason of locality if possible.
*/
BUG_ON(d_unhashed(alias));
if (!S_ISDIR(inode->i_mode))
d_move(alias, dentry);
iput(inode);
unlock_super(sb);
return alias;
}
out:
unlock_super(sb);
dentry->d_op = sb->s_root->d_op;
dentry->d_time = dentry->d_parent->d_inode->i_version;
dentry = d_splice_alias(inode, dentry);
if (dentry) {
dentry->d_op = sb->s_root->d_op;
dentry->d_time = dentry->d_parent->d_inode->i_version;
}
return dentry;
error:
unlock_super(sb);
return ERR_PTR(err);
}
static int vfat_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
struct super_block *sb = dir->i_sb;
struct inode *inode;
struct fat_slot_info sinfo;
struct timespec ts;
int err;
lock_super(sb);
ts = CURRENT_TIME_SEC;
err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo);
if (err)
goto out;
dir->i_version++;
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
brelse(sinfo.bh);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out;
}
inode->i_version++;
inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
dentry->d_time = dentry->d_parent->d_inode->i_version;
d_instantiate(dentry, inode);
out:
unlock_super(sb);
return err;
}
static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
struct super_block *sb = dir->i_sb;
struct fat_slot_info sinfo;
int err;
lock_super(sb);
err = fat_dir_empty(inode);
if (err)
goto out;
err = vfat_find(dir, &dentry->d_name, &sinfo);
if (err)
goto out;
err = fat_remove_entries(dir, &sinfo); /* and releases bh */
if (err)
goto out;
drop_nlink(dir);
clear_nlink(inode);
inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
fat_detach(inode);
out:
unlock_super(sb);
return err;
}
static int vfat_unlink(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
struct super_block *sb = dir->i_sb;
struct fat_slot_info sinfo;
int err;
lock_super(sb);
err = vfat_find(dir, &dentry->d_name, &sinfo);
if (err)
goto out;
err = fat_remove_entries(dir, &sinfo); /* and releases bh */
if (err)
goto out;
clear_nlink(inode);
inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
fat_detach(inode);
out:
unlock_super(sb);
return err;
}
static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct super_block *sb = dir->i_sb;
struct inode *inode;
struct fat_slot_info sinfo;
struct timespec ts;
int err, cluster;
lock_super(sb);
ts = CURRENT_TIME_SEC;
cluster = fat_alloc_new_dir(dir, &ts);
if (cluster < 0) {
err = cluster;
goto out;
}
err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo);
if (err)
goto out_free;
dir->i_version++;
inc_nlink(dir);
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
brelse(sinfo.bh);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
/* the directory was completed, just return a error */
goto out;
}
inode->i_version++;
inode->i_nlink = 2;
inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
dentry->d_time = dentry->d_parent->d_inode->i_version;
d_instantiate(dentry, inode);
unlock_super(sb);
return 0;
out_free:
fat_free_clusters(dir, cluster);
out:
unlock_super(sb);
return err;
}
static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct buffer_head *dotdot_bh;
struct msdos_dir_entry *dotdot_de;
struct inode *old_inode, *new_inode;
struct fat_slot_info old_sinfo, sinfo;
struct timespec ts;
loff_t dotdot_i_pos, new_i_pos;
int err, is_dir, update_dotdot, corrupt = 0;
struct super_block *sb = old_dir->i_sb;
old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
old_inode = old_dentry->d_inode;
new_inode = new_dentry->d_inode;
lock_super(sb);
err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo);
if (err)
goto out;
is_dir = S_ISDIR(old_inode->i_mode);
update_dotdot = (is_dir && old_dir != new_dir);
if (update_dotdot) {
if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
&dotdot_i_pos) < 0) {
err = -EIO;
goto out;
}
}
ts = CURRENT_TIME_SEC;
if (new_inode) {
if (is_dir) {
err = fat_dir_empty(new_inode);
if (err)
goto out;
}
new_i_pos = MSDOS_I(new_inode)->i_pos;
fat_detach(new_inode);
} else {
err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0,
&ts, &sinfo);
if (err)
goto out;
new_i_pos = sinfo.i_pos;
}
new_dir->i_version++;
fat_detach(old_inode);
fat_attach(old_inode, new_i_pos);
if (IS_DIRSYNC(new_dir)) {
err = fat_sync_inode(old_inode);
if (err)
goto error_inode;
} else
mark_inode_dirty(old_inode);
if (update_dotdot) {
int start = MSDOS_I(new_dir)->i_logstart;
dotdot_de->start = cpu_to_le16(start);
dotdot_de->starthi = cpu_to_le16(start >> 16);
mark_buffer_dirty_inode(dotdot_bh, old_inode);
if (IS_DIRSYNC(new_dir)) {
err = sync_dirty_buffer(dotdot_bh);
if (err)
goto error_dotdot;
}
drop_nlink(old_dir);
if (!new_inode)
inc_nlink(new_dir);
}
err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */
old_sinfo.bh = NULL;
if (err)
goto error_dotdot;
old_dir->i_version++;
old_dir->i_ctime = old_dir->i_mtime = ts;
if (IS_DIRSYNC(old_dir))
(void)fat_sync_inode(old_dir);
else
mark_inode_dirty(old_dir);
if (new_inode) {
drop_nlink(new_inode);
if (is_dir)
drop_nlink(new_inode);
new_inode->i_ctime = ts;
}
out:
brelse(sinfo.bh);
brelse(dotdot_bh);
brelse(old_sinfo.bh);
unlock_super(sb);
return err;
error_dotdot:
/* data cluster is shared, serious corruption */
corrupt = 1;
if (update_dotdot) {
int start = MSDOS_I(old_dir)->i_logstart;
dotdot_de->start = cpu_to_le16(start);
dotdot_de->starthi = cpu_to_le16(start >> 16);
mark_buffer_dirty_inode(dotdot_bh, old_inode);
corrupt |= sync_dirty_buffer(dotdot_bh);
}
error_inode:
fat_detach(old_inode);
fat_attach(old_inode, old_sinfo.i_pos);
if (new_inode) {
fat_attach(new_inode, new_i_pos);
if (corrupt)
corrupt |= fat_sync_inode(new_inode);
} else {
/*
* If new entry was not sharing the data cluster, it
* shouldn't be serious corruption.
*/
int err2 = fat_remove_entries(new_dir, &sinfo);
if (corrupt)
corrupt |= err2;
sinfo.bh = NULL;
}
if (corrupt < 0) {
fat_fs_error(new_dir->i_sb,
"%s: Filesystem corrupted (i_pos %lld)",
__func__, sinfo.i_pos);
}
goto out;
}
static const struct inode_operations vfat_dir_inode_operations = {
.create = vfat_create,
.lookup = vfat_lookup,
.unlink = vfat_unlink,
.mkdir = vfat_mkdir,
.rmdir = vfat_rmdir,
.rename = vfat_rename,
.setattr = fat_setattr,
.getattr = fat_getattr,
};
static int vfat_fill_super(struct super_block *sb, void *data, int silent)
{
int res;
res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
if (res)
return res;
if (MSDOS_SB(sb)->options.name_check != 's')
sb->s_root->d_op = &vfat_ci_dentry_ops;
else
sb->s_root->d_op = &vfat_dentry_ops;
return 0;
}
static int vfat_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *data, struct vfsmount *mnt)
{
return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super,
mnt);
}
static struct file_system_type vfat_fs_type = {
.owner = THIS_MODULE,
.name = "vfat",
.get_sb = vfat_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init init_vfat_fs(void)
{
return register_filesystem(&vfat_fs_type);
}
static void __exit exit_vfat_fs(void)
{
unregister_filesystem(&vfat_fs_type);
}
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("VFAT filesystem support");
MODULE_AUTHOR("Gordon Chaffee");
module_init(init_vfat_fs)
module_exit(exit_vfat_fs)
