diff options
| author | Peter Lieven <pl@kamp.de> | 2013-12-14 17:31:40 +0100 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2014-02-21 00:34:40 -0600 |
| commit | 02e1c55ddd971a565dbf473c23ed29d4e07ad42b (patch) | |
| tree | 0c30288fa91c56616a9c16d640c38ba5efa52613 | |
| parent | 9692bad34dcb0dcfc46a968ee1d7c69510d268a7 (diff) | |
block/iscsi: use a bh to schedule co reentrance
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: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 8b9dfe9098d91e06a3dd6376624307fe5fa13be8)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
| -rw-r--r-- | block/iscsi.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/block/iscsi.c b/block/iscsi.c index a2d578c0a7..a410a28e38 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); } } |