forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
122 lines
3.0 KiB
122 lines
3.0 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* 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))); |
|
out: |
|
return d_splice_alias(foundinode, dentry); |
|
}
|
|
|