[Qemu-devel] [PATCHv4 09/17] iscsi: simplify iscsi_co_discard

[Peter Lieven <pl@kamp.de>]

now that bdrv_co_discard can handle limits we do not need
the request split logic here anymore.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
---
 block/iscsi.c |   67 +++++++++++++++++++++------------------------------------
 1 file changed, 25 insertions(+), 42 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 6152ef1..be70ced 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -87,7 +87,6 @@ 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)
@@ -912,8 +911,6 @@ coroutine_fn iscsi_co_discard(BlockDriverState *bs, int64_t sector_num,
     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;
@@ -925,52 +922,38 @@ coroutine_fn iscsi_co_discard(BlockDriverState *bs, int64_t sector_num,
     }
 
     list.lba = sector_qemu2lun(sector_num, iscsilun);
-    nb_blocks = sector_qemu2lun(nb_sectors, iscsilun);
+    list.num = 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;
-        }
+    iscsi_co_init_iscsitask(iscsilun, &iTask);
 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 (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1,
+                     iscsi_co_generic_cb, &iTask) == NULL) {
+        return -EIO;
+    }
 
-        if (iTask.task != NULL) {
-            scsi_free_scsi_task(iTask.task);
-            iTask.task = NULL;
-        }
+    while (!iTask.complete) {
+        iscsi_set_events(iscsilun);
+        qemu_coroutine_yield();
+    }
 
-        if (iTask.do_retry) {
-            goto retry;
-        }
+    if (iTask.task != NULL) {
+        scsi_free_scsi_task(iTask.task);
+        iTask.task = NULL;
+    }
 
-        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.do_retry) {
+        goto retry;
+    }
 
-        if (iTask.status != SCSI_STATUS_GOOD) {
-            return -EIO;
-        }
+    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;
+    }
 
-        list.lba += list.num;
-        nb_blocks -= list.num;
+    if (iTask.status != SCSI_STATUS_GOOD) {
+        return -EIO;
     }
 
     return 0;
-- 
1.7.9.5