mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
![Dave Hansen](/assets/img/avatar_default.png)
Some filesystems, instead of simply decrementing i_nlink, simply zero it during an unlink operation. We need to catch these in addition to the decrement operations. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
246 lines
5.6 KiB
C
246 lines
5.6 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/time.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/qnx4_fs.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/buffer_head.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("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;
|
|
}
|
|
/* "" means "." ---> so paths like "/usr/lib//libc.a" work */
|
|
if (!len && (de->di_fname[0] == '.') && (de->di_fname[1] == '\0')) {
|
|
return 1;
|
|
}
|
|
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;
|
|
if (!dir->i_sb) {
|
|
printk("qnx4: no superblock on dir.\n");
|
|
return NULL;
|
|
}
|
|
bh = NULL;
|
|
block = offset = blkofs = 0;
|
|
while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
|
|
if (!bh) {
|
|
bh = qnx4_bread(dir, blkofs, 0);
|
|
if (!bh) {
|
|
blkofs++;
|
|
continue;
|
|
}
|
|
}
|
|
*res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
|
|
if (qnx4_match(len, name, bh, &offset)) {
|
|
block = qnx4_block_map( dir, blkofs );
|
|
*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, struct nameidata *nd)
|
|
{
|
|
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;
|
|
|
|
lock_kernel();
|
|
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);
|
|
|
|
if ((foundinode = iget(dir->i_sb, ino)) == NULL) {
|
|
unlock_kernel();
|
|
QNX4DEBUG(("qnx4: lookup->iget -> NULL\n"));
|
|
return ERR_PTR(-EACCES);
|
|
}
|
|
out:
|
|
unlock_kernel();
|
|
d_add(dentry, foundinode);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
#ifdef CONFIG_QNX4FS_RW
|
|
int qnx4_create(struct inode *dir, struct dentry *dentry, int mode,
|
|
struct nameidata *nd)
|
|
{
|
|
QNX4DEBUG(("qnx4: qnx4_create\n"));
|
|
if (dir == NULL) {
|
|
return -ENOENT;
|
|
}
|
|
return -ENOSPC;
|
|
}
|
|
|
|
int qnx4_rmdir(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct buffer_head *bh;
|
|
struct qnx4_inode_entry *de;
|
|
struct inode *inode;
|
|
int retval;
|
|
int ino;
|
|
|
|
QNX4DEBUG(("qnx4: qnx4_rmdir [%s]\n", dentry->d_name.name));
|
|
lock_kernel();
|
|
bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
|
|
&de, &ino);
|
|
if (bh == NULL) {
|
|
unlock_kernel();
|
|
return -ENOENT;
|
|
}
|
|
inode = dentry->d_inode;
|
|
if (inode->i_ino != ino) {
|
|
retval = -EIO;
|
|
goto end_rmdir;
|
|
}
|
|
#if 0
|
|
if (!empty_dir(inode)) {
|
|
retval = -ENOTEMPTY;
|
|
goto end_rmdir;
|
|
}
|
|
#endif
|
|
if (inode->i_nlink != 2) {
|
|
QNX4DEBUG(("empty directory has nlink!=2 (%d)\n", inode->i_nlink));
|
|
}
|
|
QNX4DEBUG(("qnx4: deleting directory\n"));
|
|
de->di_status = 0;
|
|
memset(de->di_fname, 0, sizeof de->di_fname);
|
|
de->di_mode = 0;
|
|
mark_buffer_dirty(bh);
|
|
clear_nlink(inode);
|
|
mark_inode_dirty(inode);
|
|
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
|
|
inode_dec_link_count(dir);
|
|
retval = 0;
|
|
|
|
end_rmdir:
|
|
brelse(bh);
|
|
|
|
unlock_kernel();
|
|
return retval;
|
|
}
|
|
|
|
int qnx4_unlink(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct buffer_head *bh;
|
|
struct qnx4_inode_entry *de;
|
|
struct inode *inode;
|
|
int retval;
|
|
int ino;
|
|
|
|
QNX4DEBUG(("qnx4: qnx4_unlink [%s]\n", dentry->d_name.name));
|
|
lock_kernel();
|
|
bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
|
|
&de, &ino);
|
|
if (bh == NULL) {
|
|
unlock_kernel();
|
|
return -ENOENT;
|
|
}
|
|
inode = dentry->d_inode;
|
|
if (inode->i_ino != ino) {
|
|
retval = -EIO;
|
|
goto end_unlink;
|
|
}
|
|
retval = -EPERM;
|
|
if (!inode->i_nlink) {
|
|
QNX4DEBUG(("Deleting nonexistent file (%s:%lu), %d\n",
|
|
inode->i_sb->s_id,
|
|
inode->i_ino, inode->i_nlink));
|
|
inode->i_nlink = 1;
|
|
}
|
|
de->di_status = 0;
|
|
memset(de->di_fname, 0, sizeof de->di_fname);
|
|
de->di_mode = 0;
|
|
mark_buffer_dirty(bh);
|
|
dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
|
|
mark_inode_dirty(dir);
|
|
inode->i_ctime = dir->i_ctime;
|
|
inode_dec_link_count(inode);
|
|
retval = 0;
|
|
|
|
end_unlink:
|
|
unlock_kernel();
|
|
brelse(bh);
|
|
|
|
return retval;
|
|
}
|
|
#endif
|