[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH] 9pfs: only free completed request if not flushed
From: |
Greg Kurz |
Subject: |
[Qemu-devel] [PATCH] 9pfs: only free completed request if not flushed |
Date: |
Mon, 03 Oct 2016 10:35:02 +0200 |
User-agent: |
StGit/0.17.1-dirty |
If a PDU has a flush request pending, the current code calls pdu_free()
twice:
1) pdu_complete()->pdu_free() with pdu->cancelled set, which does nothing
2) v9fs_flush()->pdu_free() with pdu->cancelled cleared, which moves the
PDU back to the free list.
This works but it complexifies the logic of pdu_free().
With this patch, pdu_complete() only calls pdu_free() if no flush request
is pending, i.e. qemu_co_queue_next() returns false.
Since pdu_free() is now supposed to be called with pdu->cancelled cleared,
the check in pdu_free() is dropped and replaced by an assertion.
Signed-off-by: Greg Kurz <address@hidden>
---
hw/9pfs/9p.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 058588d64121..f3b2340d4106 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -627,14 +627,10 @@ V9fsPDU *pdu_alloc(V9fsState *s)
void pdu_free(V9fsPDU *pdu)
{
V9fsState *s = pdu->s;
- /*
- * Cancelled pdu are added back to the freelist
- * by flush request .
- */
- if (!pdu->cancelled) {
- QLIST_REMOVE(pdu, next);
- QLIST_INSERT_HEAD(&s->free_list, pdu, next);
- }
+
+ g_assert(!pdu->cancelled);
+ QLIST_REMOVE(pdu, next);
+ QLIST_INSERT_HEAD(&s->free_list, pdu, next);
}
/*
@@ -679,9 +675,9 @@ static void coroutine_fn pdu_complete(V9fsPDU *pdu, ssize_t
len)
pdu_push_and_notify(pdu);
/* Now wakeup anybody waiting in flush for this request */
- qemu_co_queue_next(&pdu->complete);
-
- pdu_free(pdu);
+ if (!qemu_co_queue_next(&pdu->complete)) {
+ pdu_free(pdu);
+ }
}
static mode_t v9mode_to_mode(uint32_t mode, V9fsString *extension)
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Qemu-devel] [PATCH] 9pfs: only free completed request if not flushed,
Greg Kurz <=