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From: Blue Swirl <blauwirbel@gmail.com>
Date: Mon, 13 Dec 2010 20:47:47 +0000
Message-ID: <AANLkTimxDT-Sc+hoNRz087z+ihDJ4VZbD_dyyNCTg0K4@mail.gmail.com>
Subject: Re: [Qemu-devel] [PATCH] libiscsi
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To: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: qemu-devel@nongnu.org

On Mon, Dec 13, 2010 at 8:05 AM, Ronnie Sahlberg
<ronniesahlberg@gmail.com> wrote:
> This patch adds a new block driver : block.iscsi.c
> This driver interfaces with the multiplatform posix library
> for iscsi initiator/client access to iscsi devices hosted at
> git://github.com/sahlberg/libiscsi.git
>
> The patch adds the driver to interface with the iscsi library.
> It also updated the configure script to
> * by default, probe is libiscsi is available and if so, build
> =C2=A0qemu against libiscsi.
> * --enable-libiscsi
> =C2=A0Force a build against libiscsi. If libiscsi is not available
> =C2=A0the build will fail.
> * --disable-libiscsi
> =C2=A0Do not link against libiscsi, even if it is available.
>
> When linked with libiscsi, qemu gains support to access iscsi resources
> such as disks and cdrom directly, without having to make the devices visi=
ble
> to the host.
>
> You can specify devices using a iscsi url of the form :
> iscsi://<host>[:<port]/<target-iqn-name>/<lun>
>
> Example:
> -drive file=3Discsi://10.1.1.1:3260/iqn.ronnie.test/1
>
> -cdrom iscsi://10.1.1.1:3260/iqn.ronnie.test/2
>
> Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
> ---
> =C2=A0Makefile.objs | =C2=A0 =C2=A02 +-
> =C2=A0block/iscsi.c | =C2=A0528 +++++++++++++++++++++++++++++++++++++++++=
++++++++++++++++
> =C2=A0configure =C2=A0 =C2=A0 | =C2=A0 29 +++
> =C2=A03 files changed, 558 insertions(+), 1 deletions(-)
> =C2=A0create mode 100644 block/iscsi.c
>
> diff --git a/Makefile.objs b/Makefile.objs
> index cebb945..81731c5 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -22,7 +22,7 @@ block-nested-y +=3D raw.o cow.o qcow.o vdi.o vmdk.o clo=
op.o dmg.o bochs.o vpc.o vv
> =C2=A0block-nested-y +=3D qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-=
snapshot.o
> =C2=A0block-nested-y +=3D parallels.o nbd.o blkdebug.o sheepdog.o blkveri=
fy.o
> =C2=A0block-nested-$(CONFIG_WIN32) +=3D raw-win32.o
> -block-nested-$(CONFIG_POSIX) +=3D raw-posix.o
> +block-nested-$(CONFIG_POSIX) +=3D raw-posix.o iscsi.o

Please use CONFIG_ISCSI...

> =C2=A0block-nested-$(CONFIG_CURL) +=3D curl.o
>
> =C2=A0block-obj-y +=3D =C2=A0$(addprefix block/, $(block-nested-y))
> diff --git a/block/iscsi.c b/block/iscsi.c
> new file mode 100644
> index 0000000..fba5ee6
> --- /dev/null
> +++ b/block/iscsi.c
> @@ -0,0 +1,528 @@
> +/*
> + * QEMU Block driver for iSCSI images
> + *
> + * Copyright (c) 2010 Ronnie Sahlberg <ronniesahlberg@gmail.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining=
 a copy
> + * of this software and associated documentation files (the "Software"),=
 to deal
> + * in the Software without restriction, including without limitation the=
 rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or =
sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be includ=
ed in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRE=
SS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILI=
TY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHA=
LL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR =
OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISI=
NG FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALING=
S IN
> + * THE SOFTWARE.
> + */
> +
> +#include "config-host.h"
> +#ifdef CONFIG_LIBISCSI

... then this is not needed.

> +
> +#include <poll.h>
> +#include "sysemu.h"
> +#include "qemu-common.h"
> +#include "qemu-error.h"
> +#include "block_int.h"
> +
> +#include <iscsi/iscsi.h>
> +#include <iscsi/scsi-lowlevel.h>
> +
> +
> +typedef struct ISCSILUN {
> + =C2=A0 =C2=A0struct iscsi_context *iscsi;
> + =C2=A0 =C2=A0int lun;
> + =C2=A0 =C2=A0int block_size;
> + =C2=A0 =C2=A0unsigned long num_blocks;
> +} ISCSILUN;
> +
> +typedef struct ISCSIAIOCB {
> + =C2=A0 =C2=A0BlockDriverAIOCB common;
> + =C2=A0 =C2=A0QEMUIOVector *qiov;
> + =C2=A0 =C2=A0QEMUBH *bh;
> + =C2=A0 =C2=A0ISCSILUN *iscsilun;
> + =C2=A0 =C2=A0int canceled;
> + =C2=A0 =C2=A0int status;
> + =C2=A0 =C2=A0size_t read_size;
> +} ISCSIAIOCB;
> +
> +struct iscsi_task {
> + =C2=A0 =C2=A0ISCSILUN *iscsilun;
> + =C2=A0 =C2=A0int status;
> + =C2=A0 =C2=A0int complete;
> +};

Please see CODING_STYLE for struct naming and use of typedefs.

> +
> +static int
> +iscsi_is_inserted(BlockDriverState *bs)
> +{
> + =C2=A0 =C2=A0ISCSILUN *iscsilun =3D bs->opaque;
> + =C2=A0 =C2=A0struct iscsi_context *iscsi =3D iscsilun->iscsi;
> +
> + =C2=A0 =C2=A0return iscsi_is_logged_in(iscsi);
> +}
> +
> +
> +static void
> +iscsi_aio_cancel(BlockDriverAIOCB *blockacb)
> +{
> + =C2=A0 =C2=A0ISCSIAIOCB *acb =3D (ISCSIAIOCB *)blockacb;
> +
> + =C2=A0 =C2=A0acb->status =3D -EIO;
> + =C2=A0 =C2=A0acb->common.cb(acb->common.opaque, acb->status);
> + =C2=A0 =C2=A0acb->canceled =3D 1;
> +}
> +
> +static AIOPool iscsi_aio_pool =3D {
> + =C2=A0 =C2=A0.aiocb_size =C2=A0 =C2=A0 =C2=A0 =C2=A0 =3D sizeof(ISCSIAI=
OCB),
> + =C2=A0 =C2=A0.cancel =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =3D iscs=
i_aio_cancel,
> +};
> +
> +
> +static void iscsi_process_read(void *arg);
> +static void iscsi_process_write(void *arg);
> +
> +static void
> +iscsi_set_events(ISCSILUN *iscsilun)
> +{
> + =C2=A0 =C2=A0struct iscsi_context *iscsi =3D iscsilun->iscsi;
> +
> + =C2=A0 =C2=A0qemu_aio_set_fd_handler(iscsi_get_fd(iscsi), iscsi_process=
_read,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 (iscsi_which_events(iscsi)&POLLOUT)

Please insert space around operators.

> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 ?iscsi_process_write:NULL,

Also around ?:.

> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 NULL, NULL, iscsilun);
> +}
> +
> +static void
> +iscsi_process_read(void *arg)
> +{
> + =C2=A0 =C2=A0ISCSILUN *iscsilun =3D arg;
> + =C2=A0 =C2=A0struct iscsi_context *iscsi =3D iscsilun->iscsi;
> +
> + =C2=A0 =C2=A0iscsi_service(iscsi, POLLIN);
> + =C2=A0 =C2=A0iscsi_set_events(iscsilun);
> +}
> +
> +static void
> +iscsi_process_write(void *arg)
> +{
> + =C2=A0 =C2=A0ISCSILUN *iscsilun =3D arg;
> + =C2=A0 =C2=A0struct iscsi_context *iscsi =3D iscsilun->iscsi;
> +
> + =C2=A0 =C2=A0iscsi_service(iscsi, POLLOUT);
> + =C2=A0 =C2=A0iscsi_set_events(iscsilun);
> +}
> +
> +
> +static int
> +iscsi_schedule_bh(QEMUBHFunc *cb, ISCSIAIOCB *acb)
> +{
> + =C2=A0 =C2=A0acb->bh =3D qemu_bh_new(cb, acb);
> + =C2=A0 =C2=A0if (!acb->bh) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("oom: could not create iscsi bh");
> + =C2=A0 =C2=A0 =C2=A0 return -EIO;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0qemu_bh_schedule(acb->bh);
> + =C2=A0 =C2=A0return 0;
> +}
> +
> +static void
> +iscsi_readv_writev_bh_cb(void *p)
> +{
> + =C2=A0 =C2=A0ISCSIAIOCB *acb =3D p;
> +
> + =C2=A0 =C2=A0acb->common.cb(acb->common.opaque, acb->status);
> + =C2=A0 =C2=A0qemu_aio_release(acb);
> +}
> +
> +static void
> +iscsi_aio_write10_cb(struct iscsi_context *iscsi, int status,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0vo=
id *command_data, void *private_data)
> +{
> + =C2=A0 =C2=A0ISCSIAIOCB *acb =3D private_data;
> +
> + =C2=A0 =C2=A0if (acb->canceled !=3D 0) {
> + =C2=A0 =C2=A0 =C2=A0 qemu_aio_release(acb);
> + =C2=A0 =C2=A0 =C2=A0 return;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0acb->status =3D 0;
> + =C2=A0 =C2=A0if (status < 0) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("Failed to write10 data to iSCSI lun.=
 %s",
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0is=
csi_get_error(iscsi));
> + =C2=A0 =C2=A0 =C2=A0 acb->status =3D -EIO;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0iscsi_schedule_bh(iscsi_readv_writev_bh_cb, acb);
> +}
> +
> +static BlockDriverAIOCB *
> +iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0QEMUIOVector *qi=
ov, int nb_sectors,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0BlockDriverCompl=
etionFunc *cb,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0void *opaque)
> +{
> + =C2=A0 =C2=A0ISCSILUN *iscsilun =3D bs->opaque;
> + =C2=A0 =C2=A0struct iscsi_context *iscsi =3D iscsilun->iscsi;
> + =C2=A0 =C2=A0ISCSIAIOCB *acb;
> + =C2=A0 =C2=A0size_t size;
> + =C2=A0 =C2=A0unsigned char *buf;

Why unsigned? Maybe uint8_t or plain char instead?

> +
> + =C2=A0 =C2=A0acb =3D qemu_aio_get(&iscsi_aio_pool, bs, cb, opaque);
> + =C2=A0 =C2=A0if (!acb) {
> + =C2=A0 =C2=A0 =C2=A0 return NULL;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0acb->iscsilun =3D iscsilun;
> + =C2=A0 =C2=A0acb->qiov =C2=A0 =C2=A0 =3D qiov;
> +
> + =C2=A0 =C2=A0acb->canceled =C2=A0 =3D 0;
> +
> + =C2=A0 =C2=A0/* XXX we should pass the iovec to write10 to avoid the ex=
tra copy */
> + =C2=A0 =C2=A0/* this will allow us to get rid of 'buf' completely */
> + =C2=A0 =C2=A0size =3D nb_sectors * BDRV_SECTOR_SIZE;
> + =C2=A0 =C2=A0buf =3D qemu_malloc(size);
> + =C2=A0 =C2=A0qemu_iovec_to_buffer(acb->qiov, buf);
> + =C2=A0 =C2=A0if (iscsi_write10_async(iscsi, iscsilun->lun, buf, size,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 sector_num * BDRV_SECTOR_SIZE
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 / iscsilun->block_size,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 0, 0, iscsilun->block_size,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 iscsi_aio_write10_cb, acb) !=3D 0) {

When the function call is this long, perhaps it would be more readable
to assign a temporary variable with the result and use that in if
expression.

The expression sector_num * BDRV_SECTOR_SIZE / iscsilun->block_size is
used often, refactoring this to a function could make the code a bit
clearer.

> + =C2=A0 =C2=A0 =C2=A0 error_report("iSCSI: Failed to send write10 comman=
d. %s",
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0is=
csi_get_error(iscsi));
> + =C2=A0 =C2=A0 =C2=A0 qemu_free(buf);
> + =C2=A0 =C2=A0 =C2=A0 qemu_aio_release(acb);
> + =C2=A0 =C2=A0 =C2=A0 return NULL;
> + =C2=A0 =C2=A0}
> + =C2=A0 =C2=A0qemu_free(buf);
> + =C2=A0 =C2=A0iscsi_set_events(iscsilun);
> +
> + =C2=A0 =C2=A0return &acb->common;
> +}
> +
> +static void
> +iscsi_aio_read10_cb(struct iscsi_context *iscsi, int status,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 void *co=
mmand_data, void *private_data)
> +{
> + =C2=A0 =C2=A0ISCSIAIOCB *acb =3D private_data;
> + =C2=A0 =C2=A0struct scsi_task *scsi =3D command_data;
> +
> + =C2=A0 =C2=A0if (acb->canceled !=3D 0) {
> + =C2=A0 =C2=A0 =C2=A0 qemu_aio_release(acb);
> + =C2=A0 =C2=A0 =C2=A0 return;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0acb->status =3D 0;
> + =C2=A0 =C2=A0if (status < 0) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("Failed to read10 data from iSCSI lun=
. %s",
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0is=
csi_get_error(iscsi));
> + =C2=A0 =C2=A0 =C2=A0 acb->status =3D -EIO;
> + =C2=A0 =C2=A0} else {
> + =C2=A0 =C2=A0 =C2=A0 qemu_iovec_from_buffer(acb->qiov, scsi->datain.dat=
a, acb->read_size);
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0iscsi_schedule_bh(iscsi_readv_writev_bh_cb, acb);
> +}
> +
> +static BlockDriverAIOCB *
> +iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 QEMUIOVector *qiov, in=
t nb_sectors,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 BlockDriverCompletionF=
unc *cb,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 void *opaque)
> +{
> + =C2=A0 =C2=A0ISCSILUN *iscsilun =3D bs->opaque;
> + =C2=A0 =C2=A0struct iscsi_context *iscsi =3D iscsilun->iscsi;
> + =C2=A0 =C2=A0ISCSIAIOCB *acb;
> + =C2=A0 =C2=A0size_t qemu_read_size, lun_read_size;
> +
> + =C2=A0 =C2=A0qemu_read_size =3D BDRV_SECTOR_SIZE * (size_t)nb_sectors;
> + =C2=A0 =C2=A0lun_read_size =C2=A0=3D (qemu_read_size + iscsilun->block_=
size - 1)
> + =C2=A0 =C2=A0 =C2=A0/ iscsilun->block_size * iscsilun->block_size;
> +
> + =C2=A0 =C2=A0acb =3D qemu_aio_get(&iscsi_aio_pool, bs, cb, opaque);
> + =C2=A0 =C2=A0if (!acb) {
> + =C2=A0 =C2=A0 =C2=A0 return NULL;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0acb->iscsilun =3D iscsilun;
> + =C2=A0 =C2=A0acb->qiov =C2=A0 =C2=A0 =3D qiov;
> +
> + =C2=A0 =C2=A0acb->canceled =C2=A0 =3D 0;
> + =C2=A0 =C2=A0acb->read_size =C2=A0=3D qemu_read_size;
> +
> + =C2=A0 =C2=A0if (iscsi_read10_async(iscsi, iscsilun->lun,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0sector_num * BDRV_SECTOR_SIZE
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0/ iscsilun->block_size,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0lun_read_size, iscsilun->block_size,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0iscsi_aio_read10_cb, acb) !=3D 0) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("iSCSI: Failed to send read10 command=
. %s",
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0is=
csi_get_error(iscsi));
> + =C2=A0 =C2=A0 =C2=A0 qemu_aio_release(acb);
> + =C2=A0 =C2=A0 =C2=A0 return NULL;
> + =C2=A0 =C2=A0}
> + =C2=A0 =C2=A0iscsi_set_events(iscsilun);
> +
> + =C2=A0 =C2=A0return &acb->common;
> +}
> +
> +
> +static void synccache10_cb(struct iscsi_context *iscsi, int status,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0void *command_data, void *private_data)

Usually 'opaque' is used instead of 'private_data'.

> +{
> + =C2=A0 =C2=A0struct iscsi_task *task =3D private_data;
> +
> + =C2=A0 =C2=A0task->status =C2=A0 =3D status;
> + =C2=A0 =C2=A0task->complete =3D 1;
> +}
> +
> +static int
> +iscsi_flush(BlockDriverState *bs)
> +{
> + =C2=A0 =C2=A0ISCSILUN *iscsilun =3D bs->opaque;
> + =C2=A0 =C2=A0struct iscsi_context *iscsi =3D iscsilun->iscsi;
> + =C2=A0 =C2=A0struct iscsi_task task;
> +
> + =C2=A0 =C2=A0task.iscsilun =3D iscsilun;
> + =C2=A0 =C2=A0task.status =3D 0;
> + =C2=A0 =C2=A0task.complete =3D 0;
> +
> + =C2=A0 =C2=A0if (iscsi_synchronizecache10_async(iscsi, iscsilun->lun,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A00, 0, 0, 0,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0synccache10_c=
b,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0&task) !=3D 0=
) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("iSCSI: Failed to send SYNCHRONIZECAC=
HE10. %s",
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0is=
csi_get_error(iscsi));
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0return -1;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0async_context_push();
> + =C2=A0 =C2=A0while (!task.complete) {
> + =C2=A0 =C2=A0 =C2=A0 iscsi_set_events(iscsilun);
> + =C2=A0 =C2=A0 =C2=A0 qemu_aio_wait();
> + =C2=A0 =C2=A0}
> + =C2=A0 =C2=A0async_context_pop();
> + =C2=A0 =C2=A0if (task.status !=3D 0) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("iSCSI: Failed to send SYNCHRONIZECAC=
HE10: %s",
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0is=
csi_get_error(iscsi));
> + =C2=A0 =C2=A0 =C2=A0 return -EIO;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0return 0;
> +}
> +
> +static int64_t
> +iscsi_getlength(BlockDriverState *bs)
> +{
> + =C2=A0 =C2=A0ISCSILUN *iscsilun =3D bs->opaque;
> + =C2=A0 =C2=A0int64_t len;
> +
> + =C2=A0 =C2=A0len =C2=A0=3D iscsilun->num_blocks;
> + =C2=A0 =C2=A0len *=3D iscsilun->block_size;
> +
> + =C2=A0 =C2=A0return len;
> +}
> +
> +static void
> +iscsi_readcapacity10_cb(struct iscsi_context *iscsi, int status,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 void *command_data, void *private_data)
> +{
> + =C2=A0 =C2=A0struct iscsi_task *task =3D private_data;
> + =C2=A0 =C2=A0struct scsi_readcapacity10 *rc10;
> + =C2=A0 =C2=A0struct scsi_task *scsi =3D command_data;
> +
> + =C2=A0 =C2=A0if (status !=3D 0) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("iSCSI: Failed to read capacity of iS=
CSI lun. %s",
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0is=
csi_get_error(iscsi));
> + =C2=A0 =C2=A0 =C2=A0 task->status =C2=A0 =3D 1;
> + =C2=A0 =C2=A0 =C2=A0 task->complete =3D 1;
> + =C2=A0 =C2=A0 =C2=A0 return;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0rc10 =3D scsi_datain_unmarshall(scsi);
> + =C2=A0 =C2=A0if (rc10 =3D=3D NULL) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("iSCSI: Failed to unmarshall readcapa=
city10 data.");
> + =C2=A0 =C2=A0 =C2=A0 task->status =C2=A0 =3D 1;
> + =C2=A0 =C2=A0 =C2=A0 task->complete =3D 1;
> + =C2=A0 =C2=A0 =C2=A0 return;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0task->iscsilun->block_size =3D rc10->block_size;
> + =C2=A0 =C2=A0task->iscsilun->num_blocks =3D rc10->lba;
> +
> + =C2=A0 =C2=A0task->status =C2=A0 =3D 0;
> + =C2=A0 =C2=A0task->complete =3D 1;
> +}
> +
> +
> +static void
> +iscsi_connect_cb(struct iscsi_context *iscsi, int status, void *command_=
data,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0void *private_da=
ta)
> +{
> + =C2=A0 =C2=A0struct iscsi_task *task =3D private_data;
> +
> + =C2=A0 =C2=A0if (status !=3D 0) {
> + =C2=A0 =C2=A0 =C2=A0 task->status =C2=A0 =3D 1;
> + =C2=A0 =C2=A0 =C2=A0 task->complete =3D 1;
> + =C2=A0 =C2=A0 =C2=A0 return;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0if (iscsi_readcapacity10_async(iscsi, task->iscsilun->lun,=
 0, 0,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0iscsi_readcapacity10_cb, pr=
ivate_data)
> + =C2=A0 =C2=A0 =C2=A0 !=3D 0) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("iSCSI: failed to send readcapacity c=
ommand.");
> + =C2=A0 =C2=A0 =C2=A0 task->status =C2=A0 =3D 1;
> + =C2=A0 =C2=A0 =C2=A0 task->complete =3D 1;
> + =C2=A0 =C2=A0}
> +}
> +
> +/*
> + * We support iscsi url's on the form
> + * iscsi://<host>[:<port>]/<targetname>/<lun>
> + */
> +static int iscsi_open(BlockDriverState *bs, const char *filename, int fl=
ags)
> +{
> + =C2=A0 =C2=A0ISCSILUN *iscsilun =3D bs->opaque;
> + =C2=A0 =C2=A0struct iscsi_context *iscsi =3D NULL;
> + =C2=A0 =C2=A0struct iscsi_task task;
> + =C2=A0 =C2=A0char *ptr, *host, *target, *url;
> + =C2=A0 =C2=A0char *tmp;
> + =C2=A0 =C2=A0int ret, lun;
> +
> + =C2=A0 =C2=A0bzero(iscsilun, sizeof(ISCSILUN));

memset()

> +
> + =C2=A0 =C2=A0url =3D qemu_strdup(filename);
> +
> + =C2=A0 =C2=A0if (strncmp(url, "iscsi://", 8)) {
> + =C2=A0 =C2=A0 =C2=A0 error_report("iSCSI: url does not start with 'iscs=
i://'");
> + =C2=A0 =C2=A0 =C2=A0 ret =3D -EINVAL;
> + =C2=A0 =C2=A0 =C2=A0 goto failed;
> + =C2=A0 =C2=A0}
> +
> + =C2=A0 =C2=A0host =3D url + 8;
> +
> + =C2=A0 =C2=A0ptr =3D index(host, '/');

strchr()