diff options
| author | Peter Lieven <pl@kamp.de> | 2013-12-14 17:31:40 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2013-12-16 11:25:51 +0100 |
| commit | 8b9dfe9098d91e06a3dd6376624307fe5fa13be8 (patch) | |
| tree | 9802b09cee15c53db368e5351bc0a9055a45433d /block/iscsi.c | |
| parent | e157b8fdd412d48eacfbb8c67d3d58780154faa3 (diff) | |
| download | qemu-8b9dfe9098d91e06a3dd6376624307fe5fa13be8.zip | |
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>
Diffstat (limited to 'block/iscsi.c')
| -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 fa69408df9..b0e6eea199 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -68,6 +68,7 @@ typedef struct IscsiTask { int do_retry; struct scsi_task *task; Coroutine *co; + QEMUBH *bh; } IscsiTask; typedef struct IscsiAIOCB { @@ -123,6 +124,13 @@ 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) @@ -147,7 +155,8 @@ 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); } } |