From cb1b83e740384b4e0d950f3d7c81c02b8ce86c2e Mon Sep 17 00:00:00 2001 From: Peter Lieven Date: Mon, 18 Feb 2013 14:50:46 +0100 Subject: iscsi: add iscsi_truncate support 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. v4: - factor out complete readcapacity logic into a separate function - handle capacity change check condition in readcapacity function (this happens if the block_resize cmd is the first iscsi task executed after a resize on the storage) v3: - remove switch statement in iscsi_open - create separate patch for brdv_drain_all() in bdrv_truncate() v2: - add a general bdrv_drain_all() before bdrv_truncate() to avoid in-flight AIOs while the device is truncated - since no AIOs are in flight we can use a sync libiscsi call to re-read the capacity - factor out the readcapacity16 logic as it is redundant to iscsi_open() and iscsi_truncate(). Signed-off-by: Peter Lieven [allow any type of unit attention check condition in iscsi_readcapacity_sync(), as in Message-ID: <51263A2A.6070304@dlhnet.de> - Paolo] Signed-off-by: Paolo Bonzini --- block/iscsi.c | 135 ++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 88 insertions(+), 47 deletions(-) (limited to 'block/iscsi.c') diff --git a/block/iscsi.c b/block/iscsi.c index 439af6f..3d52921 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -938,6 +938,71 @@ static void iscsi_nop_timed_event(void *opaque) } #endif +static int iscsi_readcapacity_sync(IscsiLun *iscsilun) +{ + struct scsi_task *task = NULL; + struct scsi_readcapacity10 *rc10 = NULL; + struct scsi_readcapacity16 *rc16 = NULL; + int ret = 0; + int retries = ISCSI_CMD_RETRIES; + +try_again: + switch (iscsilun->type) { + case TYPE_DISK: + task = iscsi_readcapacity16_sync(iscsilun->iscsi, iscsilun->lun); + if (task == NULL || task->status != SCSI_STATUS_GOOD) { + if (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION + && task->sense.key == SCSI_SENSE_UNIT_ATTENTION + && retries-- > 0) { + scsi_free_scsi_task(task); + goto try_again; + } + error_report("iSCSI: failed to send readcapacity16 command."); + ret = -EINVAL; + goto out; + } + rc16 = scsi_datain_unmarshall(task); + if (rc16 == NULL) { + error_report("iSCSI: Failed to unmarshall readcapacity16 data."); + ret = -EINVAL; + goto out; + } + iscsilun->block_size = rc16->block_length; + iscsilun->num_blocks = rc16->returned_lba + 1; + break; + case TYPE_ROM: + task = iscsi_readcapacity10_sync(iscsilun->iscsi, iscsilun->lun, 0, 0); + if (task == NULL || task->status != SCSI_STATUS_GOOD) { + error_report("iSCSI: failed to send readcapacity10 command."); + ret = -EINVAL; + goto out; + } + rc10 = scsi_datain_unmarshall(task); + if (rc10 == NULL) { + error_report("iSCSI: Failed to unmarshall readcapacity10 data."); + ret = -EINVAL; + goto out; + } + iscsilun->block_size = rc10->block_size; + if (rc10->lba == 0) { + /* blank disk loaded */ + iscsilun->num_blocks = 0; + } else { + iscsilun->num_blocks = rc10->lba + 1; + } + break; + default: + break; + } + +out: + if (task) { + scsi_free_scsi_task(task); + } + + return ret; +} + /* * We support iscsi url's on the form * iscsi://[%@][:]// @@ -949,8 +1014,6 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags) struct iscsi_url *iscsi_url = NULL; struct scsi_task *task = NULL; struct scsi_inquiry_standard *inq = NULL; - struct scsi_readcapacity10 *rc10 = NULL; - struct scsi_readcapacity16 *rc16 = NULL; char *initiator_name = NULL; int ret; @@ -1040,50 +1103,9 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags) iscsilun->type = inq->periperal_device_type; - scsi_free_scsi_task(task); - - switch (iscsilun->type) { - case TYPE_DISK: - task = iscsi_readcapacity16_sync(iscsi, iscsilun->lun); - if (task == NULL || task->status != SCSI_STATUS_GOOD) { - error_report("iSCSI: failed to send readcapacity16 command."); - ret = -EINVAL; - goto out; - } - rc16 = scsi_datain_unmarshall(task); - if (rc16 == NULL) { - error_report("iSCSI: Failed to unmarshall readcapacity16 data."); - ret = -EINVAL; - goto out; - } - iscsilun->block_size = rc16->block_length; - iscsilun->num_blocks = rc16->returned_lba + 1; - break; - case TYPE_ROM: - task = iscsi_readcapacity10_sync(iscsi, iscsilun->lun, 0, 0); - if (task == NULL || task->status != SCSI_STATUS_GOOD) { - error_report("iSCSI: failed to send readcapacity10 command."); - ret = -EINVAL; - goto out; - } - rc10 = scsi_datain_unmarshall(task); - if (rc10 == NULL) { - error_report("iSCSI: Failed to unmarshall readcapacity10 data."); - ret = -EINVAL; - goto out; - } - iscsilun->block_size = rc10->block_size; - if (rc10->lba == 0) { - /* blank disk loaded */ - iscsilun->num_blocks = 0; - } else { - iscsilun->num_blocks = rc10->lba + 1; - } - break; - default: - break; + if ((ret = iscsi_readcapacity_sync(iscsilun)) != 0) { + goto out; } - bs->total_sectors = iscsilun->num_blocks * iscsilun->block_size / BDRV_SECTOR_SIZE ; @@ -1096,8 +1118,6 @@ static int iscsi_open(BlockDriverState *bs, const char *filename, int flags) bs->sg = 1; } - ret = 0; - #if defined(LIBISCSI_FEATURE_NOP_COUNTER) /* Set up a timer for sending out iSCSI NOPs */ iscsilun->nop_timer = qemu_new_timer_ms(rt_clock, iscsi_nop_timed_event, iscsilun); @@ -1138,6 +1158,26 @@ static void iscsi_close(BlockDriverState *bs) memset(iscsilun, 0, sizeof(IscsiLun)); } +static int iscsi_truncate(BlockDriverState *bs, int64_t offset) +{ + IscsiLun *iscsilun = bs->opaque; + int ret = 0; + + if (iscsilun->type != TYPE_DISK) { + return -ENOTSUP; + } + + if ((ret = iscsi_readcapacity_sync(iscsilun)) != 0) { + return ret; + } + + if (offset > iscsi_getlength(bs)) { + return -EINVAL; + } + + return 0; +} + static int iscsi_has_zero_init(BlockDriverState *bs) { return 0; @@ -1208,6 +1248,7 @@ 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, -- cgit v1.1