/*! 2017. 8.12 study -ing */
static int handle_remove(const char *nodename, struct device *dev)
{
struct path parent;
struct dentry *dentry;
int deleted = 0;
int err;
dentry = kern_path_locked(nodename, &parent);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
if (dentry->d_inode) {
struct kstat stat;
struct path p = {.mnt = parent.mnt, .dentry = dentry};
err = vfs_getattr(&p, &stat);
if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
struct iattr newattrs;
/*
* before unlinking this node, reset permissions
* of possible references like hardlinks
*/
newattrs.ia_uid = GLOBAL_ROOT_UID;
newattrs.ia_gid = GLOBAL_ROOT_GID;
newattrs.ia_mode = stat.mode & ~0777;
newattrs.ia_valid =
ATTR_UID|ATTR_GID|ATTR_MODE;
mutex_lock(&dentry->d_inode->i_mutex);
notify_change(dentry, &newattrs, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
err = vfs_unlink(parent.dentry->d_inode, dentry, NULL);
if (!err || err == -ENOENT)
deleted = 1;
}
} else {
err = -ENOENT;
}
dput(dentry);
mutex_unlock(&parent.dentry->d_inode->i_mutex);
path_put(&parent);
if (deleted && strchr(nodename, '/'))
delete_path(nodename);
return err;
}
static int dev_rmdir(const char *name)
{
struct path parent;
struct dentry *dentry;
int err;
dentry = kern_path_locked(name, &parent);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
if (dentry->d_inode) {
if (dentry->d_inode->i_private == &thread)
err = vfs_rmdir(parent.dentry->d_inode, dentry);
else
err = -EPERM;
} else {
err = -ENOENT;
}
dput(dentry);
mutex_unlock(&parent.dentry->d_inode->i_mutex);
path_put(&parent);
return err;
}
struct audit_fsnotify_mark *audit_alloc_mark(struct audit_krule *krule, char *pathname, int len)
{
struct audit_fsnotify_mark *audit_mark;
struct path path;
struct dentry *dentry;
struct inode *inode;
int ret;
if (pathname[0] != '/' || pathname[len-1] == '/')
return ERR_PTR(-EINVAL);
dentry = kern_path_locked(pathname, &path);
if (IS_ERR(dentry))
return (void *)dentry; /* returning an error */
inode = path.dentry->d_inode;
inode_unlock(inode);
audit_mark = kzalloc(sizeof(*audit_mark), GFP_KERNEL);
if (unlikely(!audit_mark)) {
audit_mark = ERR_PTR(-ENOMEM);
goto out;
}
fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_free_mark);
audit_mark->mark.mask = AUDIT_FS_EVENTS;
audit_mark->path = pathname;
audit_update_mark(audit_mark, dentry->d_inode);
audit_mark->rule = krule;
ret = fsnotify_add_mark(&audit_mark->mark, audit_fsnotify_group, inode, NULL, true);
if (ret < 0) {
audit_fsnotify_mark_free(audit_mark);
audit_mark = ERR_PTR(ret);
}
out:
dput(dentry);
path_put(&path);
return audit_mark;
}
