Re: [PATCH 13/16] show-pipesize-in-stat.diff

Jan Engelhardt
2007-04-02T06:48:35Z

On Apr 1 2007 22:58, Andrew Morton wrote:
>On Sun, 1 Apr 2007 20:17:24 +0200 (MEST) Jan Engelhardt <jengelh@linux01.gwdg.de> wrote:
>
>> Show the fill status of a pipe (in bytes) when stat'ing one.
>
>Is this useful? It seems rather an obscure thing, and we generally need a
>good reason to go adding Linux-specific goodies to standard system calls
>like this. What do "other operating systems" do here?

Other OS seem to always show 0, as Linux does usually. So I do not think
programs actually rely on it having any specific value.
I thought adding pipesize might be helpful in dianosing pipe cases, akin to
Miklos's procfs-fdinfo patch for regular files.

>> + }
>> + } else if (S_ISSOCK(inode->i_mode)) {
>> +#ifdef CONFIG_UNIX_MODULE
>> + loff_t (*uxsize)(struct inode *) = __symbol_get("unixsock_size");
>> + if (uxsize != NULL) {
>> + stat->size = uxsize(inode);
>> + symbol_put("unixsock_size");
>> + }
>> +#endif
>> +#if defined(CONFIG_UNIX) && !defined(CONFIG_UNIX_MODULE)
>> + stat->size = unixsock_size(inode);
>> +#endif
>> + } else {
>> + stat->size = i_size_read(inode);
>> + }
>
>That's a bit fugly.

Drop for now.

>> +loff_t unixsock_size(struct inode *inode) {
>> + struct sock *sk = unix_find_socket_byinode(inode);
>> + loff_t eax;
>> +
>> + if(sk == NULL) { return 0; }
>> + eax = sk->sk_rcvbuf;
>> + sock_put(sk);
>> + return eax;
>> +}
>> +EXPORT_SYMBOL(unixsock_size);
>
>That's wildly incorrect coding style, and it doesn't use tabs.

Which means I something really went wrong, because I knew I went through it for
cleanup.