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/*
* linux/fs/isofs/namei.c
*
* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
*
* (C) 1991 Linus Torvalds - minix filesystem
*/
#include <linux/time.h>
#include <linux/iso_fs.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/config.h> /* Joliet? */
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/dcache.h>
#include <asm/uaccess.h>
/*
* ok, we cannot use strncmp, as the name is not in our data space.
* Thus we'll have to use isofs_match. No big problem. Match also makes
* some sanity tests.
*/
static int
isofs_cmp(struct dentry * dentry, const char * compare, int dlen)
{
struct qstr qstr;
if (!compare)
return 1;
/* check special "." and ".." files */
if (dlen == 1) {
/* "." */
if (compare[0] == 0) {
if (!dentry->d_name.len)
return 0;
compare = ".";
} else if (compare[0] == 1) {
compare = "..";
dlen = 2;
}
}
qstr.name = compare;
qstr.len = dlen;
return dentry->d_op->d_compare(dentry, &dentry->d_name, &qstr);
}
/*
* isofs_find_entry()
*
* finds an entry in the specified directory with the wanted name. It
* returns the inode number of the found entry, or 0 on error.
*/
static unsigned long
isofs_find_entry(struct inode *dir, struct dentry *dentry,
unsigned long *block_rv, unsigned long* offset_rv,
char * tmpname, struct iso_directory_record * tmpde)
{
unsigned long bufsize = ISOFS_BUFFER_SIZE(dir);
unsigned char bufbits = ISOFS_BUFFER_BITS(dir);
unsigned long block, f_pos, offset, block_saved, offset_saved;
struct buffer_head * bh = NULL;
struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb);
if (!ISOFS_I(dir)->i_first_extent)
return 0;
f_pos = 0;
offset = 0;
block = 0;
while (f_pos < dir->i_size) {
struct iso_directory_record * de;
int de_len, match, i, dlen;
char *dpnt;
if (!bh) {
bh = isofs_bread(dir, block);
if (!bh)
return 0;
}
de = (struct iso_directory_record *) (bh->b_data + offset);
de_len = *(unsigned char *) de;
if (!de_len) {
brelse(bh);
bh = NULL;
f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
block = f_pos >> bufbits;
offset = 0;
continue;
}
block_saved = bh->b_blocknr;
offset_saved = offset;
offset += de_len;
f_pos += de_len;
/* Make sure we have a full directory entry */
if (offset >= bufsize) {
int slop = bufsize - offset + de_len;
memcpy(tmpde, de, slop);
offset &= bufsize - 1;
block++;
brelse(bh);
bh = NULL;
if (offset) {
bh = isofs_bread(dir, block);
if (!bh)
return 0;
memcpy((void *) tmpde + slop, bh->b_data, offset);
}
de = tmpde;
}
dlen = de->name_len[0];
dpnt = de->name;
if (sbi->s_rock &&
((i = get_rock_ridge_filename(de, tmpname, dir)))) {
dlen = i; /* possibly -1 */
dpnt = tmpname;
#ifdef CONFIG_JOLIET
} else if (sbi->s_joliet_level) {
dlen = get_joliet_filename(de, tmpname, dir);
dpnt = tmpname;
#endif
} else if (sbi->s_mapping == 'a') {
dlen = get_acorn_filename(de, tmpname, dir);
dpnt = tmpname;
} else if (sbi->s_mapping == 'n') {
dlen = isofs_name_translate(de, tmpname, dir);
dpnt = tmpname;
}
/*
* Skip hidden or associated files unless unhide is set
*/
match = 0;
if (dlen > 0 &&
(!(de->flags[-sbi->s_high_sierra] & 5)
|| sbi->s_unhide == 'y'))
{
match = (isofs_cmp(dentry,dpnt,dlen) == 0);
}
if (match) {
isofs_normalize_block_and_offset(de,
&block_saved,
&offset_saved);
*block_rv = block_saved;
*offset_rv = offset_saved;
if (bh) brelse(bh);
return 1;
}
}
if (bh) brelse(bh);
return 0;
}
struct dentry *isofs_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
{
int found;
unsigned long block, offset;
struct inode *inode;
struct page *page;
dentry->d_op = dir->i_sb->s_root->d_op;
page = alloc_page(GFP_USER);
if (!page)
return ERR_PTR(-ENOMEM);
lock_kernel();
found = isofs_find_entry(dir, dentry,
&block, &offset,
page_address(page),
1024 + page_address(page));
__free_page(page);
inode = NULL;
if (found) {
inode = isofs_iget(dir->i_sb, block, offset);
if (!inode) {
unlock_kernel();
return ERR_PTR(-EACCES);
}
}
unlock_kernel();
if (inode)
return d_splice_alias(inode, dentry);
d_add(dentry, inode);
return NULL;
}
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