[Qemu-devel] [PATCHv5 0/3] iscsi/qemu-img/block-migration enhancements

[Qemu-devel] [PATCHv5 0/3] iscsi/qemu-img/block-migration enhancements

[Peter Lieven]

this series adds logical block provisioning functions to the iscsi layer.
it also is the first step to the change of migration to coroutines in
block/iscsi.

v4->v5:
  - rebased to master + stefanha/block
  - patch1: fetching block limits page also if lbpws == 1
  - patch2: converted to get block status api
            - moved iscsi_co_init_iscsitask up to avoid memory corruption
              if we go out in an early error case
            - added alignment check
            - added max_unmap limit here if max_unmap == 0xffffffff
  - patch3: - readded because we agreed not to touch bdrv_discard after all
            - added alignment check
            - silently fail in case of a check condition


Peter Lieven (3):
  iscsi: add logical block provisioning information to iscsilun
  iscsi: add .bdrv_get_block_status
  iscsi: add .bdrv_co_discard

 block/iscsi.c |  368 ++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 285 insertions(+), 83 deletions(-)

-- 
1.7.9.5

[Qemu-devel] [PATCHv5 1/3] iscsi: add logical block provisioning information to iscsilun

[Peter Lieven]

Signed-off-by: Peter Lieven <pl@kamp.de>
---
 block/iscsi.c |   77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/block/iscsi.c b/block/iscsi.c
index 5f28c6a..185bfd3 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -50,6 +50,10 @@ typedef struct IscsiLun {
     uint64_t num_blocks;
     int events;
     QEMUTimer *nop_timer;
+    uint8_t lbpme;
+    uint8_t lbprz;
+    struct scsi_inquiry_logical_block_provisioning lbp;
+    struct scsi_inquiry_block_limits bl;
 } IscsiLun;
 
 typedef struct IscsiAIOCB {
@@ -996,6 +1000,8 @@ static int iscsi_readcapacity_sync(IscsiLun *iscsilun)
                 } else {
                     iscsilun->block_size = rc16->block_length;
                     iscsilun->num_blocks = rc16->returned_lba + 1;
+                    iscsilun->lbpme = rc16->lbpme;
+                    iscsilun->lbprz = rc16->lbprz;
                 }
             }
             break;
@@ -1048,6 +1054,37 @@ static QemuOptsList runtime_opts = {
     },
 };
 
+static struct scsi_task *iscsi_do_inquiry(struct iscsi_context *iscsi,
+                                          int lun, int evpd, int pc) {
+        int full_size;
+        struct scsi_task *task = NULL;
+        task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, 64);
+        if (task == NULL || task->status != SCSI_STATUS_GOOD) {
+            goto fail;
+        }
+        full_size = scsi_datain_getfullsize(task);
+        if (full_size > task->datain.size) {
+            scsi_free_scsi_task(task);
+
+            /* we need more data for the full list */
+            task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, full_size);
+            if (task == NULL || task->status != SCSI_STATUS_GOOD) {
+                goto fail;
+            }
+        }
+
+        return task;
+
+fail:
+        error_report("iSCSI: Inquiry command failed : %s",
+                     iscsi_get_error(iscsi));
+        if (task) {
+            scsi_free_scsi_task(task);
+            return NULL;
+        }
+        return NULL;
+}
+
 /*
  * We support iscsi url's on the form
  * iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
@@ -1177,6 +1214,46 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags)
         bs->sg = 1;
     }
 
+    if (iscsilun->lbpme) {
+        struct scsi_inquiry_logical_block_provisioning *inq_lbp;
+        task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
+                                SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING);
+        if (task == NULL) {
+            ret = -EINVAL;
+            goto out;
+        }
+        inq_lbp = scsi_datain_unmarshall(task);
+        if (inq_lbp == NULL) {
+            error_report("iSCSI: failed to unmarshall inquiry datain blob");
+            ret = -EINVAL;
+            goto out;
+        }
+        memcpy(&iscsilun->lbp, inq_lbp,
+               sizeof(struct scsi_inquiry_logical_block_provisioning));
+        scsi_free_scsi_task(task);
+        task = NULL;
+    }
+
+    if (iscsilun->lbp.lbpu || iscsilun->lbp.lbpws) {
+        struct scsi_inquiry_block_limits *inq_bl;
+        task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
+                                SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS);
+        if (task == NULL) {
+            ret = -EINVAL;
+            goto out;
+        }
+        inq_bl = scsi_datain_unmarshall(task);
+        if (inq_bl == NULL) {
+            error_report("iSCSI: failed to unmarshall inquiry datain blob");
+            ret = -EINVAL;
+            goto out;
+        }
+        memcpy(&iscsilun->bl, inq_bl,
+               sizeof(struct scsi_inquiry_block_limits));
+        scsi_free_scsi_task(task);
+        task = NULL;
+    }
+
 #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);
-- 
1.7.9.5

[Qemu-devel] [PATCHv5 2/3] iscsi: add .bdrv_get_block_status

[Peter Lieven]

this patch adds a coroutine for .bdrv_co_block_status as well as
a generic framework that can be used to build coroutines in block/iscsi.

Signed-off-by: Peter Lieven <pl@kamp.de>
---
 block/iscsi.c |  135 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 135 insertions(+)

diff --git a/block/iscsi.c b/block/iscsi.c
index 185bfd3..19afd6c 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -56,6 +56,15 @@ typedef struct IscsiLun {
     struct scsi_inquiry_block_limits bl;
 } IscsiLun;
 
+typedef struct IscsiTask {
+    int status;
+    int complete;
+    int retries;
+    int do_retry;
+    struct scsi_task *task;
+    Coroutine *co;
+} IscsiTask;
+
 typedef struct IscsiAIOCB {
     BlockDriverAIOCB common;
     QEMUIOVector *qiov;
@@ -109,6 +118,41 @@ iscsi_schedule_bh(IscsiAIOCB *acb)
     qemu_bh_schedule(acb->bh);
 }
 
+static void
+iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
+                        void *command_data, void *opaque)
+{
+    struct IscsiTask *iTask = opaque;
+    struct scsi_task *task = command_data;
+
+    iTask->complete = 1;
+    iTask->status = status;
+    iTask->do_retry = 0;
+    iTask->task = task;
+
+    if (iTask->retries-- > 0 && status == SCSI_STATUS_CHECK_CONDITION
+        && task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
+        iTask->do_retry = 1;
+        goto out;
+    }
+
+    if (status != SCSI_STATUS_GOOD) {
+        error_report("iSCSI: Failure. %s", iscsi_get_error(iscsi));
+    }
+
+out:
+    if (iTask->co) {
+        qemu_coroutine_enter(iTask->co, NULL);
+    }
+}
+
+static void iscsi_co_init_iscsitask(IscsiLun *iscsilun, struct IscsiTask *iTask)
+{
+    *iTask = (struct IscsiTask) {
+        .co         = qemu_coroutine_self(),
+        .retries    = ISCSI_CMD_RETRIES,
+    };
+}
 
 static void
 iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
@@ -852,6 +896,95 @@ iscsi_getlength(BlockDriverState *bs)
     return len;
 }
 
+static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
+                                                  int64_t sector_num,
+                                                  int nb_sectors, int *pnum)
+{
+    IscsiLun *iscsilun = bs->opaque;
+    struct scsi_get_lba_status *lbas = NULL;
+    struct scsi_lba_status_descriptor *lbasd = NULL;
+    struct IscsiTask iTask;
+    int64_t ret;
+
+    iscsi_co_init_iscsitask(iscsilun, &iTask);
+
+    if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
+        ret = -EINVAL;
+        goto out;
+    }
+
+    /* default to all sectors allocated */
+    ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | sector_num;
+    *pnum = nb_sectors;
+
+    /* LUN does not support logical block provisioning */
+    if (iscsilun->lbpme == 0) {
+        goto out;
+    }
+
+retry:
+    if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
+                                  sector_qemu2lun(sector_num, iscsilun),
+                                  8 + 16, iscsi_co_generic_cb,
+                                  &iTask) == NULL) {
+        ret = -EIO;
+        goto out;
+    }
+
+    while (!iTask.complete) {
+        iscsi_set_events(iscsilun);
+        qemu_coroutine_yield();
+    }
+
+    if (iTask.do_retry) {
+        if (iTask.task != NULL) {
+            scsi_free_scsi_task(iTask.task);
+            iTask.task = NULL;
+        }
+        goto retry;
+    }
+
+    if (iTask.status != SCSI_STATUS_GOOD) {
+        /* in case the get_lba_status_callout fails (i.e.
+         * because the device is busy or the cmd is not
+         * supported) we pretend all blocks are allocated
+         * for backwards compatiblity */
+        goto out;
+    }
+
+    lbas = scsi_datain_unmarshall(iTask.task);
+    if (lbas == NULL) {
+        ret = -EIO;
+        goto out;
+    }
+
+    lbasd = &lbas->descriptors[0];
+
+    if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
+        ret = -EIO;
+        goto out;
+    }
+
+    *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun);
+    if (*pnum > nb_sectors) {
+        *pnum = nb_sectors;
+    }
+
+    if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
+        lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
+        ret &= ~BDRV_BLOCK_DATA;
+        if (iscsilun->lbprz) {
+            ret |= BDRV_BLOCK_ZERO;
+        }
+    }
+
+out:
+    if (iTask.task != NULL) {
+        scsi_free_scsi_task(iTask.task);
+    }
+    return ret;
+}
+
 static int parse_chap(struct iscsi_context *iscsi, const char *target)
 {
     QemuOptsList *list;
@@ -1393,6 +1526,8 @@ static BlockDriver bdrv_iscsi = {
     .bdrv_getlength  = iscsi_getlength,
     .bdrv_truncate   = iscsi_truncate,
 
+    .bdrv_co_get_block_status = iscsi_co_get_block_status,
+
     .bdrv_aio_readv  = iscsi_aio_readv,
     .bdrv_aio_writev = iscsi_aio_writev,
     .bdrv_aio_flush  = iscsi_aio_flush,
-- 
1.7.9.5

[Qemu-devel] [PATCHv5 3/3] iscsi: add .bdrv_co_discard

[Peter Lieven]

Signed-off-by: Peter Lieven <pl@kamp.de>
---
 block/iscsi.c |  156 +++++++++++++++++++++++++++------------------------------
 1 file changed, 73 insertions(+), 83 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 19afd6c..cb44fb1 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -85,6 +85,7 @@ 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)
@@ -622,88 +623,6 @@ 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,
@@ -985,6 +904,77 @@ 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;
@@ -1527,12 +1517,12 @@ 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__
-- 
1.7.9.5

Re: [Qemu-devel] [PATCHv5 3/3] iscsi: add .bdrv_co_discard

[Paolo Bonzini]

Il 19/07/2013 09:19, Peter Lieven ha scritto:
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block/iscsi.c |  156 +++++++++++++++++++++++++++------------------------------
>  1 file changed, 73 insertions(+), 83 deletions(-)
> 
> diff --git a/block/iscsi.c b/block/iscsi.c
> index 19afd6c..cb44fb1 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -85,6 +85,7 @@ 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)
> @@ -622,88 +623,6 @@ 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,
> @@ -985,6 +904,77 @@ 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;
> +    }

I guess you'll later add support for lbpws.

Anyway, series looks fine.

Paolo

> +    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;
> @@ -1527,12 +1517,12 @@ 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__
> 

Re: [Qemu-devel] [PATCHv5 3/3] iscsi: add .bdrv_co_discard

[Peter Lieven]

On 19.07.2013 11:18, Paolo Bonzini wrote:
> Il 19/07/2013 09:19, Peter Lieven ha scritto:
>> Signed-off-by: Peter Lieven <pl@kamp.de>
>> ---
>>   block/iscsi.c |  156 +++++++++++++++++++++++++++------------------------------
>>   1 file changed, 73 insertions(+), 83 deletions(-)
>>
>> diff --git a/block/iscsi.c b/block/iscsi.c
>> index 19afd6c..cb44fb1 100644
>> --- a/block/iscsi.c
>> +++ b/block/iscsi.c
>> @@ -85,6 +85,7 @@ 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)
>> @@ -622,88 +623,6 @@ 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,
>> @@ -985,6 +904,77 @@ 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;
>> +    }
> I guess you'll later add support for lbpws.
It depends: I think almost all targets will support both. I would use unmap for discard and write_same for write_zeroes.

Peter
>
> Anyway, series looks fine.
Thanks. Feel free to pull it once the get_lba_status thing is upstream.

Peter