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ISCSI: Add support for thin-provisioning via discard/UNMAP and bigger LUNs

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Update the configure test for libiscsi support to detect version 1.3
or later.  Version 1.3 of libiscsi provides both READCAPACITY16 as well
as UNMAP commands.

Update the iscsi block layer to use READCAPACITY16 to detect the size of
the LUN instead of READCAPACITY10. This allows support for LUNs larger
than 2TB.

Update to implement bdrv_aio_discard() using the UNMAP command.
This allows us to use thin-provisioned LUNs from TGTD and other iSCSI
targets that support thin-provisioning.

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
[squashed in subsequent patch from Ronnie to fix off-by-one in LBA count]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Ronnie Sahlberg 2012-04-24 16:29:04 +10:00 committed by Paolo Bonzini
parent f05ae5379e
commit fa6acb0c2f
2 changed files with 77 additions and 14 deletions
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86
block/iscsi.c
View File

@ -383,6 +383,65 @@ iscsi_aio_flush(BlockDriverState *bs,
return &acb->common;
}
static void
iscsi_unmap_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
{
IscsiAIOCB *acb = opaque;
if (acb->canceled != 0) {
qemu_aio_release(acb);
scsi_free_scsi_task(acb->task);
acb->task = NULL;
return;
}
acb->status = 0;
if (status < 0) {
error_report("Failed to unmap data on iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = -EIO;
}
iscsi_schedule_bh(iscsi_readv_writev_bh_cb, acb);
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
static BlockDriverAIOCB *
iscsi_aio_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
IscsiAIOCB *acb;
struct unmap_list list[1];
acb = qemu_aio_get(&iscsi_aio_pool, bs, cb, opaque);
acb->iscsilun = iscsilun;
acb->canceled = 0;
list[0].lba = sector_qemu2lun(sector_num, iscsilun);
list[0].num = nb_sectors * BDRV_SECTOR_SIZE / iscsilun->block_size;
acb->task = iscsi_unmap_task(iscsi, iscsilun->lun,
0, 0, &list[0], 1,
iscsi_unmap_cb,
acb);
if (acb->task == NULL) {
error_report("iSCSI: Failed to send unmap command. %s",
iscsi_get_error(iscsi));
qemu_aio_release(acb);
return NULL;
}
iscsi_set_events(iscsilun);
return &acb->common;
}
static int64_t
iscsi_getlength(BlockDriverState *bs)
{
@ -396,11 +455,11 @@ iscsi_getlength(BlockDriverState *bs)
}
static void
iscsi_readcapacity10_cb(struct iscsi_context *iscsi, int status,
iscsi_readcapacity16_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
{
struct IscsiTask *itask = opaque;
struct scsi_readcapacity10 *rc10;
struct scsi_readcapacity16 *rc16;
struct scsi_task *task = command_data;
if (status != 0) {
@ -412,26 +471,25 @@ iscsi_readcapacity10_cb(struct iscsi_context *iscsi, int status,
return;
}
rc10 = scsi_datain_unmarshall(task);
if (rc10 == NULL) {
error_report("iSCSI: Failed to unmarshall readcapacity10 data.");
rc16 = scsi_datain_unmarshall(task);
if (rc16 == NULL) {
error_report("iSCSI: Failed to unmarshall readcapacity16 data.");
itask->status = 1;
itask->complete = 1;
scsi_free_scsi_task(task);
return;
}
itask->iscsilun->block_size = rc10->block_size;
itask->iscsilun->num_blocks = rc10->lba;
itask->bs->total_sectors = (uint64_t)rc10->lba *
rc10->block_size / BDRV_SECTOR_SIZE ;
itask->iscsilun->block_size = rc16->block_length;
itask->iscsilun->num_blocks = rc16->returned_lba + 1;
itask->bs->total_sectors = itask->iscsilun->num_blocks *
itask->iscsilun->block_size / BDRV_SECTOR_SIZE ;
itask->status = 0;
itask->complete = 1;
scsi_free_scsi_task(task);
}
static void
iscsi_connect_cb(struct iscsi_context *iscsi, int status, void *command_data,
void *opaque)
@ -445,10 +503,10 @@ iscsi_connect_cb(struct iscsi_context *iscsi, int status, void *command_data,
return;
}
task = iscsi_readcapacity10_task(iscsi, itask->iscsilun->lun, 0, 0,
iscsi_readcapacity10_cb, opaque);
task = iscsi_readcapacity16_task(iscsi, itask->iscsilun->lun,
iscsi_readcapacity16_cb, opaque);
if (task == NULL) {
error_report("iSCSI: failed to send readcapacity command.");
error_report("iSCSI: failed to send readcapacity16 command.");
itask->status = 1;
itask->complete = 1;
return;
@ -700,6 +758,8 @@ static BlockDriver bdrv_iscsi = {
.bdrv_aio_readv = iscsi_aio_readv,
.bdrv_aio_writev = iscsi_aio_writev,
.bdrv_aio_flush = iscsi_aio_flush,
.bdrv_aio_discard = iscsi_aio_discard,
};
static void iscsi_block_init(void)

5
configure vendored
View File

@ -2546,10 +2546,13 @@ fi
##########################################
# Do we have libiscsi
# We check for iscsi_unmap_sync() to make sure we have a
# recent enough version of libiscsi.
if test "$libiscsi" != "no" ; then
cat > $TMPC << EOF
#include <stdio.h>
#include <iscsi/iscsi.h>
int main(void) { iscsi_create_context(""); return 0; }
int main(void) { iscsi_unmap_sync(NULL,0,0,0,NULL,0); return 0; }
EOF
if compile_prog "-Werror" "-liscsi" ; then
libiscsi="yes"