From: Peter Lieven <[email protected]>
this fixes a potential segfault and performance regression.
If the coroutine is reentered directly in the iscsi_co_generic_cb
iscsi_process_{read,write} are interrupted and reentered any
time later. One the one hand this could happen after an iscsi_close
where the iscsi context is already gone (segfault). On the
other hand this limits the number of processed callbacks
in each aio_dispatch to one (potential performance regression).
Cc: [email protected]
Signed-off-by: Peter Lieven <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
(cherry picked from commit 8b9dfe9098d91e06a3dd6376624307fe5fa13be8)
Signed-off-by: Michael Roth <[email protected]>
---
block/iscsi.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index a2d578c..a410a28 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -65,6 +65,7 @@ typedef struct IscsiTask {
int do_retry;
struct scsi_task *task;
Coroutine *co;
+ QEMUBH *bh;
} IscsiTask;
typedef struct IscsiAIOCB {
@@ -121,6 +122,13 @@ iscsi_schedule_bh(IscsiAIOCB *acb)
qemu_bh_schedule(acb->bh);
}
+static void iscsi_co_generic_bh_cb(void *opaque)
+{
+ struct IscsiTask *iTask = opaque;
+ qemu_bh_delete(iTask->bh);
+ qemu_coroutine_enter(iTask->co, NULL);
+}
+
static void
iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
@@ -145,7 +153,8 @@ iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
out:
if (iTask->co) {
- qemu_coroutine_enter(iTask->co, NULL);
+ iTask->bh = qemu_bh_new(iscsi_co_generic_bh_cb, iTask);
+ qemu_bh_schedule(iTask->bh);
}
}
--
1.7.9.5
