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Date: Fri, 3 Dec 2010 20:32:17 +0000
Message-ID: <AANLkTinw95RxZGntr3ccSfWKfjUaKmFTGyLNvHB-HVLS@mail.gmail.com>
Subject: Re: [Qemu-devel] [PATCH 01/14] ./block/iscsi/init.c
From: Stefan Hajnoczi <stefanha@gmail.com>
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To: ronniesahlberg@gmail.com
Cc: qemu-devel@nongnu.org

On Fri, Dec 3, 2010 at 11:09 AM,  <ronniesahlberg@gmail.com> wrote:
> @@ -0,0 +1,215 @@
> +/*
> + =A0 Copyright (C) 2010 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
> +
> + =A0 This program is free software; you can redistribute it and/or modif=
y
> + =A0 it under the terms of the GNU General Public License as published b=
y
> + =A0 the Free Software Foundation; either version 2 of the License, or
> + =A0 (at your option) any later version.

You want the library to be GPL, not LGPL?

> +struct iscsi_context *
> +iscsi_create_context(const char *initiator_name)
> +{
> + =A0 =A0 =A0 struct iscsi_context *iscsi;
> +
> + =A0 =A0 =A0 iscsi =3D malloc(sizeof(struct iscsi_context));
> + =A0 =A0 =A0 if (iscsi =3D=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return NULL;
> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 bzero(iscsi, sizeof(struct iscsi_context));
> +
> + =A0 =A0 =A0 iscsi->initiator_name =3D strdup(initiator_name);
> + =A0 =A0 =A0 if (iscsi->initiator_name =3D=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 free(iscsi);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return NULL;
> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 iscsi->fd =3D -1;
> +
> + =A0 =A0 =A0 /* use a "random" isid */
> + =A0 =A0 =A0 srandom(getpid() ^ time(NULL));

The random number generator has global state and the library may
interfere if the program also uses the srandom() interface.

> + =A0 =A0 =A0 iscsi_set_random_isid(iscsi);
> +
> + =A0 =A0 =A0 return iscsi;
> +}
> +
> +int
> +iscsi_set_random_isid(struct iscsi_context *iscsi)
> +{
> + =A0 =A0 =A0 iscsi->isid[0] =3D 0x80;
> + =A0 =A0 =A0 iscsi->isid[1] =3D random()&0xff;
> + =A0 =A0 =A0 iscsi->isid[2] =3D random()&0xff;
> + =A0 =A0 =A0 iscsi->isid[3] =3D random()&0xff;
> + =A0 =A0 =A0 iscsi->isid[4] =3D 0;
> + =A0 =A0 =A0 iscsi->isid[5] =3D 0;
> +
> + =A0 =A0 =A0 return 0;
> +}

Is there an interface to set a specific isid value?  Users will
probably want to use a permanent value.

> +int
> +iscsi_destroy_context(struct iscsi_context *iscsi)
> +{
> + =A0 =A0 =A0 struct iscsi_pdu *pdu;
> +
> + =A0 =A0 =A0 if (iscsi =3D=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return 0;
> + =A0 =A0 =A0 }
> + =A0 =A0 =A0 if (iscsi->initiator_name !=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 free(discard_const(iscsi->initiator_name));
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi->initiator_name =3D NULL;
> + =A0 =A0 =A0 }
> + =A0 =A0 =A0 if (iscsi->target_name !=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 free(discard_const(iscsi->target_name));
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi->target_name =3D NULL;
> + =A0 =A0 =A0 }
> + =A0 =A0 =A0 if (iscsi->alias !=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 free(discard_const(iscsi->alias));
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi->alias =3D NULL;
> + =A0 =A0 =A0 }

All these if statements are unnecessary.  free(NULL) is a nop.

> + =A0 =A0 =A0 if (iscsi->fd !=3D -1) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi_disconnect(iscsi);

Perhaps disconnect before freeing struct members?

> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 if (iscsi->inbuf !=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 free(iscsi->inbuf);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi->inbuf =3D NULL;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi->insize =3D 0;
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi->inpos =3D 0;
> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 while ((pdu =3D iscsi->outqueue)) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 SLIST_REMOVE(&iscsi->outqueue, pdu);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 pdu->callback(iscsi, SCSI_STATUS_CANCELLED,=
 NULL,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 pdu->private_da=
ta);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi_free_pdu(iscsi, pdu);
> + =A0 =A0 =A0 }
> + =A0 =A0 =A0 while ((pdu =3D iscsi->waitpdu)) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 SLIST_REMOVE(&iscsi->waitpdu, pdu);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 pdu->callback(iscsi, SCSI_STATUS_CANCELLED,=
 NULL,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 pdu->private_da=
ta);
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 iscsi_free_pdu(iscsi, pdu);
> + =A0 =A0 =A0 }

Could these callbacks expect iscsi to still be valid?  A safer order
would seem to be: disconnect, cancel all, free.

> +
> + =A0 =A0 =A0 if (iscsi->error_string !=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 free(iscsi->error_string);
> + =A0 =A0 =A0 }
> +
> + =A0 =A0 =A0 free(iscsi);
> +
> + =A0 =A0 =A0 return 0;
> +}
> +
> +
> +
> +void
> +iscsi_set_error(struct iscsi_context *iscsi, const char *error_string, .=
..)
> +{
> + =A0 =A0 =A0 va_list ap;
> + =A0 =A0 =A0 char *str;
> +
> + =A0 =A0 =A0 va_start(ap, error_string);
> + =A0 =A0 =A0 if (vasprintf(&str, error_string, ap) < 0) {

This function is available in GNU and BSD.  Not sure what level of
portability you are targeting (e.g. what about Windows)?

> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 /* not much we can do here */

You need to assign str =3D NULL here.  Otherwise its value is undefined
on GNU systems.

> + =A0 =A0 =A0 }
> + =A0 =A0 =A0 if (iscsi->error_string !=3D NULL) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 free(iscsi->error_string);
> + =A0 =A0 =A0 }
> + =A0 =A0 =A0 iscsi->error_string =3D str;
> + =A0 =A0 =A0 va_end(ap);
> +}
> +
> +
> +char *

const char *?

> +iscsi_get_error(struct iscsi_context *iscsi)
> +{
> + =A0 =A0 =A0 return iscsi->error_string;
> +}

Stefan