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[Qemu-block] [PATCH 1/5] nbd: strict nbd_wr_syncv
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-block] [PATCH 1/5] nbd: strict nbd_wr_syncv |
Date: |
Tue, 16 May 2017 12:45:29 +0300 |
nbd_wr_syncv is called either from coroutine or from client negotiation
code, when socket is in blocking mode. So, -EAGAIN is impossible.
Furthermore, EAGAIN is confusing, as, what to read/write again? With
EAGAIN as a return code we don't know how much data is already
read or written by the function, so in case of EAGAIN the whole
communication is broken.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
nbd/common.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/nbd/common.c b/nbd/common.c
index dccbb8e9de..4db45b3ede 100644
--- a/nbd/common.c
+++ b/nbd/common.c
@@ -20,6 +20,10 @@
#include "qapi/error.h"
#include "nbd-internal.h"
+/* nbd_wr_syncv
+ * The function may be called from coroutine or from non-coroutine context.
+ * When called from non-coroutine context @ioc must be in blocking mode.
+ */
ssize_t nbd_wr_syncv(QIOChannel *ioc,
struct iovec *iov,
size_t niov,
@@ -42,11 +46,8 @@ ssize_t nbd_wr_syncv(QIOChannel *ioc,
len = qio_channel_writev(ioc, local_iov, nlocal_iov, &local_err);
}
if (len == QIO_CHANNEL_ERR_BLOCK) {
- if (qemu_in_coroutine()) {
- qio_channel_yield(ioc, do_read ? G_IO_IN : G_IO_OUT);
- } else {
- return -EAGAIN;
- }
+ assert(qemu_in_coroutine());
+ qio_channel_yield(ioc, do_read ? G_IO_IN : G_IO_OUT);
continue;
}
if (len < 0) {
--
2.11.1
- [Qemu-block] [PATCH 0/5] nbd: error path refactoring, Vladimir Sementsov-Ogievskiy, 2017/05/16
- [Qemu-block] [PATCH 1/5] nbd: strict nbd_wr_syncv,
Vladimir Sementsov-Ogievskiy <=
- [Qemu-block] [PATCH 3/5] nbd: add errp parameter to nbd_wr_syncv(), Vladimir Sementsov-Ogievskiy, 2017/05/16
- [Qemu-block] [PATCH 4/5] nbd: add errp to read_sync, write_sync and drop_sync, Vladimir Sementsov-Ogievskiy, 2017/05/16
- [Qemu-block] [PATCH 2/5] nbd: read_sync and friends: return 0 on success, Vladimir Sementsov-Ogievskiy, 2017/05/16
- [Qemu-block] [PATCH 5/5] nbd/client.c: use errp instead of LOG, Vladimir Sementsov-Ogievskiy, 2017/05/16
- Re: [Qemu-block] [PATCH 0/5] nbd: error path refactoring, Paolo Bonzini, 2017/05/16
- Re: [Qemu-block] [Qemu-devel] [PATCH 0/5] nbd: error path refactoring, no-reply, 2017/05/16