this patch adds iscsi_truncate which effectively allows for online resizing of iscsi volumes. for this to work you have to resize the volume on your storage and then call block_resize command in qemu which will issue a readcapacity16 to update the capacity.
Signed-off-by: Peter Lieven <p...@kamp.de> --- block/iscsi.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) diff --git a/block/iscsi.c b/block/iscsi.c index deb3b68..37f12b3 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -67,6 +67,12 @@ typedef struct IscsiAIOCB { #endif } IscsiAIOCB; +struct IscsiTask { + IscsiLun *iscsilun; + int status; + int complete; +}; + #define NOP_INTERVAL 5000 #define MAX_NOP_FAILURES 3 @@ -700,6 +706,73 @@ iscsi_getlength(BlockDriverState *bs) return len; } +static void +iscsi_readcapacity16_cb(struct iscsi_context *iscsi, int status, + void *command_data, void *opaque) +{ + struct IscsiTask *itask = opaque; + struct scsi_readcapacity16 *rc16; + struct scsi_task *task = command_data; + + if (status != 0) { + error_report("iSCSI: Failed to read capacity of iSCSI lun. %s", + iscsi_get_error(iscsi)); + itask->status = 1; + itask->complete = 1; + scsi_free_scsi_task(task); + return; + } + + 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 = rc16->block_length; + itask->iscsilun->num_blocks = rc16->returned_lba + 1; + + itask->status = 0; + itask->complete = 1; + scsi_free_scsi_task(task); +} + +static int iscsi_truncate(BlockDriverState *bs, int64_t offset) +{ + IscsiLun *iscsilun = bs->opaque; + struct IscsiTask itask; + struct scsi_task *task = NULL; + + if (iscsilun->type != TYPE_DISK) { + return -ENOTSUP; + } + + itask.iscsilun = iscsilun; + itask.status = 0; + itask.complete = 0; + + task = iscsi_readcapacity16_task(iscsilun->iscsi, iscsilun->lun, + iscsi_readcapacity16_cb, &itask); + if (task == NULL) { + error_report("iSCSI: failed to send readcapacity16 command."); + return -EINVAL; + } + + while (!itask.complete) { + iscsi_set_events(iscsilun); + qemu_aio_wait(); + } + + if (offset > iscsi_getlength(bs)) { + return -EINVAL; + } + + return 0; +} + static int parse_chap(struct iscsi_context *iscsi, const char *target) { QemuOptsList *list; @@ -1093,6 +1166,7 @@ static BlockDriver bdrv_iscsi = { .create_options = iscsi_create_options, .bdrv_getlength = iscsi_getlength, + .bdrv_truncate = iscsi_truncate, .bdrv_aio_readv = iscsi_aio_readv, .bdrv_aio_writev = iscsi_aio_writev, -- 1.7.9.5