From 2865e534fce4969a316a5ba764b65e540da08cee Mon Sep 17 00:00:00 2001 Message-Id: <2865e534fce4969a316a5ba764b65e540da08cee.1389014116.git.minovotn@redhat.com> In-Reply-To: References: From: Paolo Bonzini Date: Mon, 9 Dec 2013 14:08:53 +0100 Subject: [PATCH 05/50] iscsi: split discard requests in multiple parts RH-Author: Paolo Bonzini Message-id: <1386598178-11845-8-git-send-email-pbonzini@redhat.com> Patchwork-id: 56044 O-Subject: [RHEL 7.0 qemu-kvm PATCH 07/52] iscsi: split discard requests in multiple parts Bugzilla: 1007815 RH-Acked-by: Jeffrey Cody RH-Acked-by: Fam Zheng RH-Acked-by: Stefan Hajnoczi From: Peter Lieven Replace .bdrv_aio_discard with .bdrv_co_discard so that discard requests can be split in multiple parts, each for a small amount of sectors. This is useful because we expose a generic API with no limit on the amount of sectors that can be unmapped in one request. Signed-off-by: Peter Lieven Signed-off-by: Paolo Bonzini (cherry picked from commit 65f3e33964bc4bb634d61463814a4ccca794e3c0) --- block/iscsi.c | 156 +++++++++++++++++++++++++++------------------------------- 1 file changed, 73 insertions(+), 83 deletions(-) Signed-off-by: Michal Novotny --- block/iscsi.c | 156 +++++++++++++++++++++++++++------------------------------- 1 file changed, 73 insertions(+), 83 deletions(-) diff --git a/block/iscsi.c b/block/iscsi.c index f8d021a..3a34eb7 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -87,6 +87,7 @@ typedef struct IscsiAIOCB { #define NOP_INTERVAL 5000 #define MAX_NOP_FAILURES 3 #define ISCSI_CMD_RETRIES 5 +#define ISCSI_MAX_UNMAP 131072 static void iscsi_bh_cb(void *p) @@ -624,88 +625,6 @@ iscsi_aio_flush(BlockDriverState *bs, return &acb->common; } -static int iscsi_aio_discard_acb(IscsiAIOCB *acb); - -static void -iscsi_unmap_cb(struct iscsi_context *iscsi, int status, - void *command_data, void *opaque) -{ - IscsiAIOCB *acb = opaque; - - if (acb->canceled != 0) { - return; - } - - acb->status = 0; - if (status != 0) { - if (status == SCSI_STATUS_CHECK_CONDITION - && acb->task->sense.key == SCSI_SENSE_UNIT_ATTENTION - && acb->retries-- > 0) { - scsi_free_scsi_task(acb->task); - acb->task = NULL; - if (iscsi_aio_discard_acb(acb) == 0) { - iscsi_set_events(acb->iscsilun); - return; - } - } - error_report("Failed to unmap data on iSCSI lun. %s", - iscsi_get_error(iscsi)); - acb->status = -EIO; - } - - iscsi_schedule_bh(acb); -} - -static int iscsi_aio_discard_acb(IscsiAIOCB *acb) { - struct iscsi_context *iscsi = acb->iscsilun->iscsi; - struct unmap_list list[1]; - - acb->canceled = 0; - acb->bh = NULL; - acb->status = -EINPROGRESS; - acb->buf = NULL; - - list[0].lba = sector_qemu2lun(acb->sector_num, acb->iscsilun); - list[0].num = acb->nb_sectors * BDRV_SECTOR_SIZE / acb->iscsilun->block_size; - - acb->task = iscsi_unmap_task(iscsi, acb->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)); - return -1; - } - - return 0; -} - -static BlockDriverAIOCB * -iscsi_aio_discard(BlockDriverState *bs, - int64_t sector_num, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque) -{ - IscsiLun *iscsilun = bs->opaque; - IscsiAIOCB *acb; - - acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque); - - acb->iscsilun = iscsilun; - acb->nb_sectors = nb_sectors; - acb->sector_num = sector_num; - acb->retries = ISCSI_CMD_RETRIES; - - if (iscsi_aio_discard_acb(acb) != 0) { - qemu_aio_release(acb); - return NULL; - } - - iscsi_set_events(iscsilun); - - return &acb->common; -} - #ifdef __linux__ static void iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status, @@ -988,6 +907,77 @@ out: return ret; } +static int +coroutine_fn iscsi_co_discard(BlockDriverState *bs, int64_t sector_num, + int nb_sectors) +{ + IscsiLun *iscsilun = bs->opaque; + struct IscsiTask iTask; + struct unmap_list list; + uint32_t nb_blocks; + uint32_t max_unmap; + + if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) { + return -EINVAL; + } + + if (!iscsilun->lbp.lbpu) { + /* UNMAP is not supported by the target */ + return 0; + } + + list.lba = sector_qemu2lun(sector_num, iscsilun); + nb_blocks = sector_qemu2lun(nb_sectors, iscsilun); + + max_unmap = iscsilun->bl.max_unmap; + if (max_unmap == 0xffffffff) { + max_unmap = ISCSI_MAX_UNMAP; + } + + while (nb_blocks > 0) { + iscsi_co_init_iscsitask(iscsilun, &iTask); + list.num = nb_blocks; + if (list.num > max_unmap) { + list.num = max_unmap; + } +retry: + if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1, + iscsi_co_generic_cb, &iTask) == NULL) { + return -EIO; + } + + while (!iTask.complete) { + iscsi_set_events(iscsilun); + qemu_coroutine_yield(); + } + + if (iTask.task != NULL) { + scsi_free_scsi_task(iTask.task); + iTask.task = NULL; + } + + if (iTask.do_retry) { + goto retry; + } + + if (iTask.status == SCSI_STATUS_CHECK_CONDITION) { + /* the target might fail with a check condition if it + is not happy with the alignment of the UNMAP request + we silently fail in this case */ + return 0; + } + + if (iTask.status != SCSI_STATUS_GOOD) { + return -EIO; + } + + list.lba += list.num; + nb_blocks -= list.num; + } + + return 0; +} + static int parse_chap(struct iscsi_context *iscsi, const char *target) { QemuOptsList *list; @@ -1541,12 +1531,12 @@ static BlockDriver bdrv_iscsi = { .bdrv_truncate = iscsi_truncate, .bdrv_co_get_block_status = iscsi_co_get_block_status, + .bdrv_co_discard = iscsi_co_discard, .bdrv_aio_readv = iscsi_aio_readv, .bdrv_aio_writev = iscsi_aio_writev, .bdrv_aio_flush = iscsi_aio_flush, - .bdrv_aio_discard = iscsi_aio_discard, .bdrv_has_zero_init = iscsi_has_zero_init, #ifdef __linux__ -- 1.7.11.7