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[Qemu-devel] [PULL 07/12] 9pfs: only free completed request if not flush
From: |
Greg Kurz |
Subject: |
[Qemu-devel] [PULL 07/12] 9pfs: only free completed request if not flushed |
Date: |
Mon, 17 Oct 2016 17:05:49 +0200 |
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 df8aa726c9a1..f0dc2ce589cd 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)
--
2.5.5
- [Qemu-devel] [PULL 00/12] 9p patches for 2.8 20161017, Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 02/12] 9pfs: fix potential host memory leak in v9fs_read, Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 01/12] 9pfs: allocate space for guest originated empty strings, Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 06/12] 9pfs: drop useless check in pdu_free(), Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 05/12] 9pfs: use coroutine_fn annotation in hw/9pfs/9p.[ch], Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 04/12] 9pfs: use coroutine_fn annotation in hw/9pfs/co*.[ch], Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 03/12] 9pfs: fsdev: drop useless extern annotation for functions, Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 08/12] virtio-9p: add reset handler, Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 07/12] 9pfs: only free completed request if not flushed,
Greg Kurz <=
- [Qemu-devel] [PULL 11/12] 9pfs: fix memory leak in v9fs_link, Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 10/12] 9pfs: fix memory leak in v9fs_xattrcreate, Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 09/12] 9pfs: fix information leak in xattr read, Greg Kurz, 2016/10/17
- [Qemu-devel] [PULL 12/12] 9pfs: fix memory leak in v9fs_write, Greg Kurz, 2016/10/17
- Re: [Qemu-devel] [PULL 00/12] 9p patches for 2.8 20161017, Peter Maydell, 2016/10/17