static struct dentry *isofs_export_get_parent(struct dentry *child)
{
unsigned long parent_block = 0;
unsigned long parent_offset = 0;
struct inode *child_inode = child->d_inode;
struct iso_inode_info *e_child_inode = ISOFS_I(child_inode);
struct iso_directory_record *de = NULL;
struct buffer_head * bh = NULL;
struct dentry *rv = NULL;
if (!S_ISDIR(child_inode->i_mode)) {
printk(KERN_ERR "isofs: isofs_export_get_parent(): "
"child is not a directory!\n");
rv = ERR_PTR(-EACCES);
goto out;
}
if (e_child_inode->i_iget5_offset != 0) {
printk(KERN_ERR "isofs: isofs_export_get_parent(): "
"child directory not normalized!\n");
rv = ERR_PTR(-EACCES);
goto out;
}
parent_block = e_child_inode->i_iget5_block;
bh = sb_bread(child_inode->i_sb, parent_block);
if (bh == NULL) {
rv = ERR_PTR(-EACCES);
goto out;
}
de = (struct iso_directory_record*)bh->b_data;
parent_offset = (unsigned long)isonum_711(de->length);
de = (struct iso_directory_record*)(bh->b_data + parent_offset);
if ((isonum_711(de->name_len) != 1) || (de->name[0] != 1)) {
printk(KERN_ERR "isofs: Unable to find the \"..\" "
"directory for NFS.\n");
rv = ERR_PTR(-EACCES);
goto out;
}
isofs_normalize_block_and_offset(de, &parent_block, &parent_offset);
rv = d_obtain_alias(isofs_iget(child_inode->i_sb, parent_block,
parent_offset));
out:
if (bh)
brelse(bh);
return rv;
}
/*
* 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;
}
}
/* This function is surprisingly simple. The trick is understanding
* that "child" is always a directory. So, to find its parent, you
* simply need to find its ".." entry, normalize its block and offset,
* and return the underlying inode. See the comments for
* isofs_normalize_block_and_offset(). */
static struct dentry *isofs_export_get_parent(struct dentry *child)
{
unsigned long parent_block = 0;
unsigned long parent_offset = 0;
struct inode *child_inode = child->d_inode;
struct iso_inode_info *e_child_inode = ISOFS_I(child_inode);
struct iso_directory_record *de = NULL;
struct buffer_head * bh = NULL;
struct dentry *rv = NULL;
/* "child" must always be a directory. */
if (!S_ISDIR(child_inode->i_mode)) {
printk(KERN_ERR "isofs: isofs_export_get_parent(): "
"child is not a directory!\n");
rv = ERR_PTR(-EACCES);
goto out;
}
/* It is an invariant that the directory offset is zero. If
* it is not zero, it means the directory failed to be
* normalized for some reason. */
if (e_child_inode->i_iget5_offset != 0) {
printk(KERN_ERR "isofs: isofs_export_get_parent(): "
"child directory not normalized!\n");
rv = ERR_PTR(-EACCES);
goto out;
}
/* The child inode has been normalized such that its
* i_iget5_block value points to the "." entry. Fortunately,
* the ".." entry is located in the same block. */
parent_block = e_child_inode->i_iget5_block;
/* Get the block in question. */
bh = sb_bread(child_inode->i_sb, parent_block);
if (bh == NULL) {
rv = ERR_PTR(-EACCES);
goto out;
}
/* This is the "." entry. */
de = (struct iso_directory_record*)bh->b_data;
/* The ".." entry is always the second entry. */
parent_offset = (unsigned long)isonum_711(de->length);
de = (struct iso_directory_record*)(bh->b_data + parent_offset);
/* Verify it is in fact the ".." entry. */
if ((isonum_711(de->name_len) != 1) || (de->name[0] != 1)) {
printk(KERN_ERR "isofs: Unable to find the \"..\" "
"directory for NFS.\n");
rv = ERR_PTR(-EACCES);
goto out;
}
/* Normalize */
isofs_normalize_block_and_offset(de, &parent_block, &parent_offset);
rv = d_obtain_alias(isofs_iget(child_inode->i_sb, parent_block,
parent_offset));
out:
if (bh)
brelse(bh);
return rv;
}
