int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
{
struct dnotify_struct *dn = NULL;
struct dnotify_struct *odn;
struct dnotify_struct **prev;
struct inode *inode;
int turning_off = (arg & ~DN_MULTISHOT) == 0;
int error = 0;
if (!turning_off && !dir_notify_enable)
return -EINVAL;
inode = filp->f_dentry->d_inode;
if (!S_ISDIR(inode->i_mode))
return -ENOTDIR;
if (!turning_off) {
dn = kmem_cache_alloc(dn_cache, SLAB_KERNEL);
if (dn == NULL)
return -ENOMEM;
}
write_lock(&dn_lock);
prev = &inode->i_dnotify;
for (odn = *prev; odn != NULL; prev = &odn->dn_next, odn = *prev)
if (odn->dn_filp == filp)
break;
if (odn != NULL) {
if (turning_off) {
*prev = odn->dn_next;
redo_inode_mask(inode);
dn = odn;
goto out_free;
}
odn->dn_fd = fd;
odn->dn_mask |= arg;
inode->i_dnotify_mask |= arg & ~DN_MULTISHOT;
goto out_free;
}
if (turning_off)
goto out;
if ((error = security_file_set_fowner(filp)))
goto out_free;
filp->f_owner.pid = current->pid;
filp->f_owner.uid = current->uid;
filp->f_owner.euid = current->euid;
dn->dn_magic = DNOTIFY_MAGIC;
dn->dn_mask = arg;
dn->dn_fd = fd;
dn->dn_filp = filp;
inode->i_dnotify_mask |= arg & ~DN_MULTISHOT;
dn->dn_next = inode->i_dnotify;
inode->i_dnotify = dn;
out:
write_unlock(&dn_lock);
return error;
out_free:
kmem_cache_free(dn_cache, dn);
goto out;
}
int __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
int force)
{
int err;
err = security_file_set_fowner(filp);
if (err)
return err;
f_modown(filp, pid, type, force);
return 0;
}
void __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
int force)
{
security_file_set_fowner(filp);
f_modown(filp, pid, type, force);
}
