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/*
* fs/bfs/dir.c
* BFS directory operations.
* Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
*/
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/bfs_fs.h>
#include <linux/locks.h>
#include "bfs_defs.h"
#undef DEBUG
#ifdef DEBUG
#define dprintf(x...) printf(x)
#else
#define dprintf(x...)
#endif
static int bfs_add_entry(struct inode * dir, const char * name, int namelen, int ino);
static struct buffer_head * bfs_find_entry(struct inode * dir,
const char * name, int namelen, struct bfs_dirent ** res_dir);
static int bfs_readdir(struct file * f, void * dirent, filldir_t filldir)
{
struct inode * dir = f->f_dentry->d_inode;
struct buffer_head * bh;
struct bfs_dirent * de;
kdev_t dev = dir->i_dev;
unsigned int offset;
int block;
if (f->f_pos & (BFS_DIRENT_SIZE-1)) {
printf("Bad f_pos=%08lx for %s:%08lx\n", (unsigned long)f->f_pos,
bdevname(dev), dir->i_ino);
return -EBADF;
}
while (f->f_pos < dir->i_size) {
offset = f->f_pos & (BFS_BSIZE-1);
block = dir->iu_sblock + (f->f_pos >> BFS_BSIZE_BITS);
bh = sb_bread(dir->i_sb, block);
if (!bh) {
f->f_pos += BFS_BSIZE - offset;
continue;
}
do {
de = (struct bfs_dirent *)(bh->b_data + offset);
if (de->ino) {
int size = strnlen(de->name, BFS_NAMELEN);
if (filldir(dirent, de->name, size, f->f_pos, de->ino, DT_UNKNOWN) < 0) {
brelse(bh);
return 0;
}
}
offset += BFS_DIRENT_SIZE;
f->f_pos += BFS_DIRENT_SIZE;
} while (offset < BFS_BSIZE && f->f_pos < dir->i_size);
brelse(bh);
}
UPDATE_ATIME(dir);
return 0;
}
struct file_operations bfs_dir_operations = {
read: generic_read_dir,
readdir: bfs_readdir,
fsync: file_fsync,
};
extern void dump_imap(const char *, struct super_block *);
static int bfs_create(struct inode * dir, struct dentry * dentry, int mode)
{
int err;
struct inode * inode;
struct super_block * s = dir->i_sb;
unsigned long ino;
inode = new_inode(s);
if (!inode)
return -ENOSPC;
ino = find_first_zero_bit(s->su_imap, s->su_lasti);
if (ino > s->su_lasti) {
iput(inode);
return -ENOSPC;
}
set_bit(ino, s->su_imap);
s->su_freei--;
inode->i_uid = current->fsuid;
inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_blocks = inode->i_blksize = 0;
inode->i_op = &bfs_file_inops;
inode->i_fop = &bfs_file_operations;
inode->i_mapping->a_ops = &bfs_aops;
inode->i_mode = mode;
inode->i_ino = inode->iu_dsk_ino = ino;
inode->iu_sblock = inode->iu_eblock = 0;
insert_inode_hash(inode);
mark_inode_dirty(inode);
dump_imap("create",s);
err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, inode->i_ino);
if (err) {
inode->i_nlink--;
mark_inode_dirty(inode);
iput(inode);
return err;
}
d_instantiate(dentry, inode);
return 0;
}
static struct dentry * bfs_lookup(struct inode * dir, struct dentry * dentry)
{
struct inode * inode = NULL;
struct buffer_head * bh;
struct bfs_dirent * de;
if (dentry->d_name.len > BFS_NAMELEN)
return ERR_PTR(-ENAMETOOLONG);
bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
if (bh) {
unsigned long ino = le32_to_cpu(de->ino);
brelse(bh);
inode = iget(dir->i_sb, ino);
if (!inode)
return ERR_PTR(-EACCES);
}
d_add(dentry, inode);
return NULL;
}
static int bfs_link(struct dentry * old, struct inode * dir, struct dentry * new)
{
struct inode * inode = old->d_inode;
int err;
if (S_ISDIR(inode->i_mode))
return -EPERM;
err = bfs_add_entry(dir, new->d_name.name, new->d_name.len, inode->i_ino);
if (err)
return err;
inode->i_nlink++;
inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(inode);
atomic_inc(&inode->i_count);
d_instantiate(new, inode);
return 0;
}
static int bfs_unlink(struct inode * dir, struct dentry * dentry)
{
int error = -ENOENT;
struct inode * inode;
struct buffer_head * bh;
struct bfs_dirent * de;
inode = dentry->d_inode;
bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
if (!bh || de->ino != inode->i_ino)
goto out_brelse;
if (!inode->i_nlink) {
printf("unlinking non-existent file %s:%lu (nlink=%d)\n", bdevname(inode->i_dev),
inode->i_ino, inode->i_nlink);
inode->i_nlink = 1;
}
de->ino = 0;
dir->i_version = ++event;
mark_buffer_dirty(bh);
dir->i_ctime = dir->i_mtime = CURRENT_TIME;
mark_inode_dirty(dir);
inode->i_nlink--;
inode->i_ctime = dir->i_ctime;
mark_inode_dirty(inode);
error = 0;
out_brelse:
brelse(bh);
return error;
}
static int bfs_rename(struct inode * old_dir, struct dentry * old_dentry,
struct inode * new_dir, struct dentry * new_dentry)
{
struct inode * old_inode, * new_inode;
struct buffer_head * old_bh, * new_bh;
struct bfs_dirent * old_de, * new_de;
int error = -ENOENT;
old_bh = new_bh = NULL;
old_inode = old_dentry->d_inode;
if (S_ISDIR(old_inode->i_mode))
return -EINVAL;
old_bh = bfs_find_entry(old_dir,
old_dentry->d_name.name,
old_dentry->d_name.len, &old_de);
if (!old_bh || old_de->ino != old_inode->i_ino)
goto end_rename;
error = -EPERM;
new_inode = new_dentry->d_inode;
new_bh = bfs_find_entry(new_dir,
new_dentry->d_name.name,
new_dentry->d_name.len, &new_de);
if (new_bh && !new_inode) {
brelse(new_bh);
new_bh = NULL;
}
if (!new_bh) {
error = bfs_add_entry(new_dir,
new_dentry->d_name.name,
new_dentry->d_name.len, old_inode->i_ino);
if (error)
goto end_rename;
}
old_de->ino = 0;
old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
old_dir->i_version = ++event;
mark_inode_dirty(old_dir);
if (new_inode) {
new_inode->i_nlink--;
new_inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(new_inode);
}
mark_buffer_dirty(old_bh);
error = 0;
end_rename:
brelse(old_bh);
brelse(new_bh);
return error;
}
struct inode_operations bfs_dir_inops = {
create: bfs_create,
lookup: bfs_lookup,
link: bfs_link,
unlink: bfs_unlink,
rename: bfs_rename,
};
static int bfs_add_entry(struct inode * dir, const char * name, int namelen, int ino)
{
struct buffer_head * bh;
struct bfs_dirent * de;
int block, sblock, eblock, off;
kdev_t dev;
int i;
dprintf("name=%s, namelen=%d\n", name, namelen);
if (!namelen)
return -ENOENT;
if (namelen > BFS_NAMELEN)
return -ENAMETOOLONG;
dev = dir->i_dev;
sblock = dir->iu_sblock;
eblock = dir->iu_eblock;
for (block=sblock; block<=eblock; block++) {
bh = sb_bread(dir->i_sb, block);
if(!bh)
return -ENOSPC;
for (off=0; off<BFS_BSIZE; off+=BFS_DIRENT_SIZE) {
de = (struct bfs_dirent *)(bh->b_data + off);
if (!de->ino) {
if ((block-sblock)*BFS_BSIZE + off >= dir->i_size) {
dir->i_size += BFS_DIRENT_SIZE;
dir->i_ctime = CURRENT_TIME;
}
dir->i_mtime = CURRENT_TIME;
mark_inode_dirty(dir);
dir->i_version = ++event;
de->ino = ino;
for (i=0; i<BFS_NAMELEN; i++)
de->name[i] = (i < namelen) ? name[i] : 0;
mark_buffer_dirty(bh);
brelse(bh);
return 0;
}
}
brelse(bh);
}
return -ENOSPC;
}
static inline int bfs_namecmp(int len, const char * name, const char * buffer)
{
if (len < BFS_NAMELEN && buffer[len])
return 0;
return !memcmp(name, buffer, len);
}
static struct buffer_head * bfs_find_entry(struct inode * dir,
const char * name, int namelen, struct bfs_dirent ** res_dir)
{
unsigned long block, offset;
struct buffer_head * bh;
struct bfs_sb_info * info;
struct bfs_dirent * de;
*res_dir = NULL;
info = &dir->i_sb->u.bfs_sb;
if (namelen > BFS_NAMELEN)
return NULL;
bh = NULL;
block = offset = 0;
while (block * BFS_BSIZE + offset < dir->i_size) {
if (!bh) {
bh = sb_bread(dir->i_sb, dir->iu_sblock + block);
if (!bh) {
block++;
continue;
}
}
de = (struct bfs_dirent *)(bh->b_data + offset);
offset += BFS_DIRENT_SIZE;
if (de->ino && bfs_namecmp(namelen, name, de->name)) {
*res_dir = de;
return bh;
}
if (offset < bh->b_size)
continue;
brelse(bh);
bh = NULL;
offset = 0;
block++;
}
brelse(bh);
return NULL;
}
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