mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-21 13:33:24 +07:00
126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
/*
|
|
* QNX4 file system, Linux implementation.
|
|
*
|
|
* Version : 0.2.1
|
|
*
|
|
* Using parts of the xiafs filesystem.
|
|
*
|
|
* History :
|
|
*
|
|
* 01-06-1998 by Richard Frowijn : first release.
|
|
* 21-06-1998 by Frank Denis : dcache support, fixed error codes.
|
|
* 04-07-1998 by Frank Denis : first step for rmdir/unlink.
|
|
*/
|
|
|
|
#include <linux/buffer_head.h>
|
|
#include "qnx4.h"
|
|
|
|
|
|
/*
|
|
* check if the filename is correct. For some obscure reason, qnx writes a
|
|
* new file twice in the directory entry, first with all possible options at 0
|
|
* and for a second time the way it is, they want us not to access the qnx
|
|
* filesystem when whe are using linux.
|
|
*/
|
|
static int qnx4_match(int len, const char *name,
|
|
struct buffer_head *bh, unsigned long *offset)
|
|
{
|
|
struct qnx4_inode_entry *de;
|
|
int namelen, thislen;
|
|
|
|
if (bh == NULL) {
|
|
printk(KERN_WARNING "qnx4: matching unassigned buffer !\n");
|
|
return 0;
|
|
}
|
|
de = (struct qnx4_inode_entry *) (bh->b_data + *offset);
|
|
*offset += QNX4_DIR_ENTRY_SIZE;
|
|
if ((de->di_status & QNX4_FILE_LINK) != 0) {
|
|
namelen = QNX4_NAME_MAX;
|
|
} else {
|
|
namelen = QNX4_SHORT_NAME_MAX;
|
|
}
|
|
thislen = strlen( de->di_fname );
|
|
if ( thislen > namelen )
|
|
thislen = namelen;
|
|
if (len != thislen) {
|
|
return 0;
|
|
}
|
|
if (strncmp(name, de->di_fname, len) == 0) {
|
|
if ((de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)) != 0) {
|
|
return 1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct buffer_head *qnx4_find_entry(int len, struct inode *dir,
|
|
const char *name, struct qnx4_inode_entry **res_dir, int *ino)
|
|
{
|
|
unsigned long block, offset, blkofs;
|
|
struct buffer_head *bh;
|
|
|
|
*res_dir = NULL;
|
|
bh = NULL;
|
|
block = offset = blkofs = 0;
|
|
while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
|
|
if (!bh) {
|
|
block = qnx4_block_map(dir, blkofs);
|
|
if (block)
|
|
bh = sb_bread(dir->i_sb, block);
|
|
if (!bh) {
|
|
blkofs++;
|
|
continue;
|
|
}
|
|
}
|
|
*res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
|
|
if (qnx4_match(len, name, bh, &offset)) {
|
|
*ino = block * QNX4_INODES_PER_BLOCK +
|
|
(offset / QNX4_DIR_ENTRY_SIZE) - 1;
|
|
return bh;
|
|
}
|
|
if (offset < bh->b_size) {
|
|
continue;
|
|
}
|
|
brelse(bh);
|
|
bh = NULL;
|
|
offset = 0;
|
|
blkofs++;
|
|
}
|
|
brelse(bh);
|
|
*res_dir = NULL;
|
|
return NULL;
|
|
}
|
|
|
|
struct dentry * qnx4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
|
|
{
|
|
int ino;
|
|
struct qnx4_inode_entry *de;
|
|
struct qnx4_link_info *lnk;
|
|
struct buffer_head *bh;
|
|
const char *name = dentry->d_name.name;
|
|
int len = dentry->d_name.len;
|
|
struct inode *foundinode = NULL;
|
|
|
|
if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino)))
|
|
goto out;
|
|
/* The entry is linked, let's get the real info */
|
|
if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) {
|
|
lnk = (struct qnx4_link_info *) de;
|
|
ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) *
|
|
QNX4_INODES_PER_BLOCK +
|
|
lnk->dl_inode_ndx;
|
|
}
|
|
brelse(bh);
|
|
|
|
foundinode = qnx4_iget(dir->i_sb, ino);
|
|
if (IS_ERR(foundinode)) {
|
|
QNX4DEBUG((KERN_ERR "qnx4: lookup->iget -> error %ld\n",
|
|
PTR_ERR(foundinode)));
|
|
return ERR_CAST(foundinode);
|
|
}
|
|
out:
|
|
d_add(dentry, foundinode);
|
|
|
|
return NULL;
|
|
}
|