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/*
* linux/fs/msdos/namei.c
*
* Written 1992,1993 by Werner Almesberger
* Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
* Rewritten for constant inumbers 1999 by Al Viro
*/
#define __NO_VERSION__
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/msdos_fs.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <asm/uaccess.h>
#define MSDOS_DEBUG 0
#define PRINTK(x)
/* MS-DOS "device special files" */
static const char *reserved_names[] = {
"CON ","PRN ","NUL ","AUX ",
"LPT1 ","LPT2 ","LPT3 ","LPT4 ",
"COM1 ","COM2 ","COM3 ","COM4 ",
NULL };
/* Characters that are undesirable in an MS-DOS file name */
static char bad_chars[] = "*?<>|\"";
static char bad_if_strict_pc[] = "+=,; ";
static char bad_if_strict_atari[] = " "; /* GEMDOS is less restrictive */
#define bad_if_strict(opts) ((opts)->atari ? bad_if_strict_atari : bad_if_strict_pc)
/* Must die */
void msdos_put_super(struct super_block *sb)
{
fat_put_super(sb);
}
/***** Formats an MS-DOS file name. Rejects invalid names. */
static int msdos_format_name(const char *name,int len,
char *res,struct fat_mount_options *opts)
/* conv is relaxed/normal/strict, name is proposed name,
* len is the length of the proposed name, res is the result name,
* dotsOK is if hidden files get dots.
*/
{
char *walk;
const char **reserved;
unsigned char c;
int space;
if (name[0] == '.') { /* dotfile because . and .. already done */
if (opts->dotsOK) {
/* Get rid of dot - test for it elsewhere */
name++; len--;
}
else if (!opts->atari) return -EINVAL;
}
/* disallow names that _really_ start with a dot for MS-DOS, GEMDOS does
* not care */
space = !opts->atari;
c = 0;
for (walk = res; len && walk-res < 8; walk++) {
c = *name++;
len--;
if (opts->conversion != 'r' && strchr(bad_chars,c))
return -EINVAL;
if (opts->conversion == 's' && strchr(bad_if_strict(opts),c))
return -EINVAL;
if (c >= 'A' && c <= 'Z' && opts->conversion == 's')
return -EINVAL;
if (c < ' ' || c == ':' || c == '\\') return -EINVAL;
/* 0xE5 is legal as a first character, but we must substitute 0x05 */
/* because 0xE5 marks deleted files. Yes, DOS really does this. */
/* It seems that Microsoft hacked DOS to support non-US characters */
/* after the 0xE5 character was already in use to mark deleted files. */
if((res==walk) && (c==0xE5)) c=0x05;
if (c == '.') break;
space = (c == ' ');
*walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c-32 : c;
}
if (space) return -EINVAL;
if (opts->conversion == 's' && len && c != '.') {
c = *name++;
len--;
if (c != '.') return -EINVAL;
}
while (c != '.' && len--) c = *name++;
if (c == '.') {
while (walk-res < 8) *walk++ = ' ';
while (len > 0 && walk-res < MSDOS_NAME) {
c = *name++;
len--;
if (opts->conversion != 'r' && strchr(bad_chars,c))
return -EINVAL;
if (opts->conversion == 's' &&
strchr(bad_if_strict(opts),c))
return -EINVAL;
if (c < ' ' || c == ':' || c == '\\')
return -EINVAL;
if (c == '.') {
if (opts->conversion == 's')
return -EINVAL;
break;
}
if (c >= 'A' && c <= 'Z' && opts->conversion == 's')
return -EINVAL;
space = c == ' ';
*walk++ = (!opts->nocase && c >= 'a' && c <= 'z') ? c-32 : c;
}
if (space) return -EINVAL;
if (opts->conversion == 's' && len) return -EINVAL;
}
while (walk-res < MSDOS_NAME) *walk++ = ' ';
if (!opts->atari)
/* GEMDOS is less stupid and has no reserved names */
for (reserved = reserved_names; *reserved; reserved++)
if (!strncmp(res,*reserved,8)) return -EINVAL;
return 0;
}
/***** Locates a directory entry. Uses unformatted name. */
static int msdos_find(struct inode *dir,const char *name,int len,
struct buffer_head **bh,struct msdos_dir_entry **de,int *ino)
{
int res;
char dotsOK;
char msdos_name[MSDOS_NAME];
dotsOK = MSDOS_SB(dir->i_sb)->options.dotsOK;
res = msdos_format_name(name,len, msdos_name,&MSDOS_SB(dir->i_sb)->options);
if (res < 0)
return -ENOENT;
res = fat_scan(dir,msdos_name,bh,de,ino);
if (!res && dotsOK) {
if (name[0]=='.') {
if (!((*de)->attr & ATTR_HIDDEN))
res = -ENOENT;
} else {
if ((*de)->attr & ATTR_HIDDEN)
res = -ENOENT;
}
}
return res;
}
/*
* Compute the hash for the msdos 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 msdos fs routines will
* return ENOENT or EINVAL as appropriate.
*/
static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
{
struct fat_mount_options *options = & (MSDOS_SB(dentry->d_sb)->options);
int error;
char msdos_name[MSDOS_NAME];
error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
if (!error)
qstr->hash = full_name_hash(msdos_name, MSDOS_NAME);
return 0;
}
/*
* Compare two msdos names. If either of the names are invalid,
* we fall back to doing the standard name comparison.
*/
static int msdos_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
{
struct fat_mount_options *options = & (MSDOS_SB(dentry->d_sb)->options);
int error;
char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
error = msdos_format_name(a->name, a->len, a_msdos_name, options);
if (error)
goto old_compare;
error = msdos_format_name(b->name, b->len, b_msdos_name, options);
if (error)
goto old_compare;
error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
out:
return error;
old_compare:
error = 1;
if (a->len == b->len)
error = memcmp(a->name, b->name, a->len);
goto out;
}
static struct dentry_operations msdos_dentry_operations = {
d_hash: msdos_hash,
d_compare: msdos_cmp,
};
/*
* AV. Wrappers for FAT sb operations. Is it wise?
*/
/***** Get inode using directory and name */
struct dentry *msdos_lookup(struct inode *dir,struct dentry *dentry)
{
struct super_block *sb = dir->i_sb;
struct inode *inode = NULL;
struct msdos_dir_entry *de;
struct buffer_head *bh = NULL;
int ino,res;
PRINTK (("msdos_lookup\n"));
dentry->d_op = &msdos_dentry_operations;
res = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &bh,
&de, &ino);
if (res == -ENOENT)
goto add;
if (res < 0)
goto out;
inode = fat_build_inode(sb, de, ino, &res);
if (res)
goto out;
add:
d_add(dentry, inode);
res = 0;
out:
if (bh)
fat_brelse(sb, bh);
return ERR_PTR(res);
}
/***** Creates a directory entry (name is already formatted). */
static int msdos_add_entry(struct inode *dir, const char *name,
struct buffer_head **bh,
struct msdos_dir_entry **de,
int *ino,
int is_dir, int is_hid)
{
struct super_block *sb = dir->i_sb;
int res;
if ((res = fat_add_entries(dir, 1, bh, de, ino))<0)
return res;
/*
* XXX all times should be set by caller upon successful completion.
*/
dir->i_ctime = dir->i_mtime = CURRENT_TIME;
mark_inode_dirty(dir);
memcpy((*de)->name,name,MSDOS_NAME);
(*de)->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
if (is_hid)
(*de)->attr |= ATTR_HIDDEN;
(*de)->start = 0;
(*de)->starthi = 0;
fat_date_unix2dos(dir->i_mtime,&(*de)->time,&(*de)->date);
(*de)->size = 0;
fat_mark_buffer_dirty(sb, *bh);
return 0;
}
/*
* AV. Huh??? It's exported. Oughtta check usage.
*/
/***** Create a file */
int msdos_create(struct inode *dir,struct dentry *dentry,int mode)
{
struct super_block *sb = dir->i_sb;
struct buffer_head *bh;
struct msdos_dir_entry *de;
struct inode *inode;
int ino,res,is_hid;
char msdos_name[MSDOS_NAME];
res = msdos_format_name(dentry->d_name.name,dentry->d_name.len,
msdos_name, &MSDOS_SB(sb)->options);
if (res < 0)
return res;
is_hid = (dentry->d_name.name[0]=='.') && (msdos_name[0]!='.');
/* Have to do it due to foo vs. .foo conflicts */
if (fat_scan(dir,msdos_name,&bh,&de,&ino) >= 0) {
fat_brelse(sb, bh);
return -EINVAL;
}
inode = NULL;
res = msdos_add_entry(dir, msdos_name, &bh, &de, &ino, 0, is_hid);
if (res)
return res;
inode = fat_build_inode(dir->i_sb, de, ino, &res);
fat_brelse(sb, bh);
if (!inode)
return res;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(inode);
d_instantiate(dentry, inode);
return 0;
}
/***** Remove a directory */
int msdos_rmdir(struct inode *dir, struct dentry *dentry)
{
struct super_block *sb = dir->i_sb;
struct inode *inode = dentry->d_inode;
int res,ino;
struct buffer_head *bh;
struct msdos_dir_entry *de;
bh = NULL;
res = msdos_find(dir, dentry->d_name.name, dentry->d_name.len,
&bh, &de, &ino);
if (res < 0)
goto rmdir_done;
/*
* Check whether the directory is not in use, then check
* whether it is empty.
*/
res = fat_dir_empty(inode);
if (res)
goto rmdir_done;
de->name[0] = DELETED_FLAG;
fat_mark_buffer_dirty(sb, bh);
fat_detach(inode);
inode->i_nlink = 0;
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
dir->i_nlink--;
mark_inode_dirty(inode);
mark_inode_dirty(dir);
res = 0;
rmdir_done:
fat_brelse(sb, bh);
return res;
}
/***** Make a directory */
int msdos_mkdir(struct inode *dir,struct dentry *dentry,int mode)
{
struct super_block *sb = dir->i_sb;
struct buffer_head *bh;
struct msdos_dir_entry *de;
struct inode *inode;
int res,is_hid;
char msdos_name[MSDOS_NAME];
int ino;
res = msdos_format_name(dentry->d_name.name,dentry->d_name.len,
msdos_name, &MSDOS_SB(sb)->options);
if (res < 0)
return res;
is_hid = (dentry->d_name.name[0]=='.') && (msdos_name[0]!='.');
/* foo vs .foo situation */
if (fat_scan(dir,msdos_name,&bh,&de,&ino) >= 0)
goto out_exist;
res = msdos_add_entry(dir, msdos_name, &bh, &de, &ino, 1, is_hid);
if (res)
goto out_unlock;
inode = fat_build_inode(dir->i_sb, de, ino, &res);
if (!inode) {
fat_brelse(sb, bh);
goto out_unlock;
}
res = 0;
dir->i_nlink++;
inode->i_nlink = 2; /* no need to mark them dirty */
res = fat_new_dir(inode, dir, 0);
if (res)
goto mkdir_error;
fat_brelse(sb, bh);
d_instantiate(dentry, inode);
res = 0;
out_unlock:
return res;
mkdir_error:
printk(KERN_WARNING "msdos_mkdir: error=%d, attempting cleanup\n", res);
inode->i_nlink = 0;
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
dir->i_nlink--;
mark_inode_dirty(inode);
mark_inode_dirty(dir);
de->name[0] = DELETED_FLAG;
fat_mark_buffer_dirty(sb, bh);
fat_brelse(sb, bh);
fat_detach(inode);
iput(inode);
goto out_unlock;
out_exist:
fat_brelse(sb, bh);
res = -EINVAL;
goto out_unlock;
}
/***** Unlink a file */
int msdos_unlink( struct inode *dir, struct dentry *dentry)
{
struct super_block *sb = dir->i_sb;
struct inode *inode = dentry->d_inode;
int res,ino;
struct buffer_head *bh;
struct msdos_dir_entry *de;
bh = NULL;
res = msdos_find(dir, dentry->d_name.name, dentry->d_name.len,
&bh, &de, &ino);
if (res < 0)
goto unlink_done;
de->name[0] = DELETED_FLAG;
fat_mark_buffer_dirty(sb, bh);
fat_detach(inode);
fat_brelse(sb, bh);
inode->i_nlink = 0;
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
mark_inode_dirty(inode);
mark_inode_dirty(dir);
res = 0;
unlink_done:
return res;
}
static int do_msdos_rename(struct inode *old_dir, char *old_name,
struct dentry *old_dentry,
struct inode *new_dir,char *new_name, struct dentry *new_dentry,
struct buffer_head *old_bh,
struct msdos_dir_entry *old_de, int old_ino, int is_hid)
{
struct super_block *sb = old_dir->i_sb;
struct buffer_head *new_bh=NULL,*dotdot_bh=NULL;
struct msdos_dir_entry *new_de,*dotdot_de;
struct inode *old_inode,*new_inode;
int new_ino,dotdot_ino;
int error;
int is_dir;
old_inode = old_dentry->d_inode;
new_inode = new_dentry->d_inode;
is_dir = S_ISDIR(old_inode->i_mode);
if (fat_scan(new_dir,new_name,&new_bh,&new_de,&new_ino)>=0 &&!new_inode)
goto degenerate_case;
if (is_dir) {
if (new_inode) {
error = fat_dir_empty(new_inode);
if (error)
goto out;
}
error = fat_scan(old_inode, MSDOS_DOTDOT, &dotdot_bh,
&dotdot_de, &dotdot_ino);
if (error < 0) {
printk(KERN_WARNING
"MSDOS: %s/%s, get dotdot failed, ret=%d\n",
old_dentry->d_parent->d_name.name,
old_dentry->d_name.name, error);
goto out;
}
}
if (!new_bh) {
error = msdos_add_entry(new_dir, new_name, &new_bh, &new_de,
&new_ino, is_dir, is_hid);
if (error)
goto out;
}
new_dir->i_version = ++event;
/* There we go */
if (new_inode)
fat_detach(new_inode);
old_de->name[0] = DELETED_FLAG;
fat_mark_buffer_dirty(sb, old_bh);
fat_detach(old_inode);
fat_attach(old_inode, new_ino);
if (is_hid)
MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
else
MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
mark_inode_dirty(old_inode);
old_dir->i_version = ++event;
old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
mark_inode_dirty(old_dir);
if (new_inode) {
new_inode->i_nlink--;
new_inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(new_inode);
}
if (dotdot_bh) {
dotdot_de->start = CT_LE_W(MSDOS_I(new_dir)->i_logstart);
dotdot_de->starthi = CT_LE_W((MSDOS_I(new_dir)->i_logstart) >> 16);
fat_mark_buffer_dirty(sb, dotdot_bh);
old_dir->i_nlink--;
mark_inode_dirty(old_dir);
if (new_inode) {
new_inode->i_nlink--;
mark_inode_dirty(new_inode);
} else {
new_dir->i_nlink++;
mark_inode_dirty(new_dir);
}
}
error = 0;
out:
fat_brelse(sb, new_bh);
fat_brelse(sb, dotdot_bh);
return error;
degenerate_case:
error = -EINVAL;
if (new_de!=old_de)
goto out;
if (is_hid)
MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
else
MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
mark_inode_dirty(old_inode);
old_dir->i_version = ++event;
old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
mark_inode_dirty(old_dir);
return 0;
}
/***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
int msdos_rename(struct inode *old_dir,struct dentry *old_dentry,
struct inode *new_dir,struct dentry *new_dentry)
{
struct super_block *sb = old_dir->i_sb;
struct buffer_head *old_bh;
struct msdos_dir_entry *old_de;
int old_ino, error;
int is_hid,old_hid; /* if new file and old file are hidden */
char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
error = msdos_format_name(old_dentry->d_name.name,
old_dentry->d_name.len,old_msdos_name,
&MSDOS_SB(old_dir->i_sb)->options);
if (error < 0)
goto rename_done;
error = msdos_format_name(new_dentry->d_name.name,
new_dentry->d_name.len,new_msdos_name,
&MSDOS_SB(new_dir->i_sb)->options);
if (error < 0)
goto rename_done;
is_hid = (new_dentry->d_name.name[0]=='.') && (new_msdos_name[0]!='.');
old_hid = (old_dentry->d_name.name[0]=='.') && (old_msdos_name[0]!='.');
error = fat_scan(old_dir, old_msdos_name, &old_bh, &old_de, &old_ino);
if (error < 0)
goto rename_done;
error = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
new_dir, new_msdos_name, new_dentry,
old_bh, old_de, (ino_t)old_ino, is_hid);
fat_brelse(sb, old_bh);
rename_done:
return error;
}
/* The public inode operations for the msdos fs */
struct inode_operations msdos_dir_inode_operations = {
create: msdos_create,
lookup: msdos_lookup,
unlink: msdos_unlink,
mkdir: msdos_mkdir,
rmdir: msdos_rmdir,
rename: msdos_rename,
setattr: fat_notify_change,
};
struct super_block *msdos_read_super(struct super_block *sb,void *data, int silent)
{
struct super_block *res;
MSDOS_SB(sb)->options.isvfat = 0;
res = fat_read_super(sb, data, silent, &msdos_dir_inode_operations);
if (res)
sb->s_root->d_op = &msdos_dentry_operations;
return res;
}
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