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[Qemu-devel] [PATCH 02/17] nbd/client: refactor nbd_read_eof
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-devel] [PATCH 02/17] nbd/client: refactor nbd_read_eof |
Date: |
Fri, 4 Aug 2017 18:14:25 +0300 |
Refactor nbd_read_eof to return 1 on success, 0 on eof, when no
data was read and <0 for other cases, because returned size of
read data is not actually used.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
nbd/nbd-internal.h | 34 +++++++++++++++++++++++++---------
nbd/client.c | 5 -----
tests/qemu-iotests/083.out | 4 ++--
3 files changed, 27 insertions(+), 16 deletions(-)
diff --git a/nbd/nbd-internal.h b/nbd/nbd-internal.h
index 396ddb4d3e..3fb0b6098a 100644
--- a/nbd/nbd-internal.h
+++ b/nbd/nbd-internal.h
@@ -77,21 +77,37 @@
#define NBD_ESHUTDOWN 108
/* nbd_read_eof
- * Tries to read @size bytes from @ioc. Returns number of bytes actually read.
- * May return a value >= 0 and < size only on EOF, i.e. when iteratively called
- * qio_channel_readv() returns 0. So, there is no need to call nbd_read_eof
- * iteratively.
+ * Tries to read @size bytes from @ioc.
+ * Returns 1 on success
+ * 0 on eof, when no data was read (errp is not set)
+ * -EINVAL on eof, when some data < @size was read until eof
+ * < 0 on read fail
*/
-static inline ssize_t nbd_read_eof(QIOChannel *ioc, void *buffer, size_t size,
- Error **errp)
+static inline int nbd_read_eof(QIOChannel *ioc, void *buffer, size_t size,
+ Error **errp)
{
struct iovec iov = { .iov_base = buffer, .iov_len = size };
+ ssize_t ret;
+
/* Sockets are kept in blocking mode in the negotiation phase. After
* that, a non-readable socket simply means that another thread stole
* our request/reply. Synchronization is done with recv_coroutine, so
* that this is coroutine-safe.
*/
- return nbd_rwv(ioc, &iov, 1, size, true, errp);
+
+ assert(size > 0);
+
+ ret = nbd_rwv(ioc, &iov, 1, size, true, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+
+ if (ret != size) {
+ error_setg(errp, "End of file");
+ return -EINVAL;
+ }
+
+ return 1;
}
/* nbd_read
@@ -100,9 +116,9 @@ static inline ssize_t nbd_read_eof(QIOChannel *ioc, void
*buffer, size_t size,
static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size,
Error **errp)
{
- ssize_t ret = nbd_read_eof(ioc, buffer, size, errp);
+ int ret = nbd_read_eof(ioc, buffer, size, errp);
- if (ret >= 0 && ret != size) {
+ if (ret == 0) {
ret = -EINVAL;
error_setg(errp, "End of file");
}
diff --git a/nbd/client.c b/nbd/client.c
index f1c16b588f..4556056daa 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -925,11 +925,6 @@ ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply
*reply, Error **errp)
return ret;
}
- if (ret != sizeof(buf)) {
- error_setg(errp, "read failed");
- return -EINVAL;
- }
-
/* Reply
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
[ 4 .. 7] error (0 == no error)
diff --git a/tests/qemu-iotests/083.out b/tests/qemu-iotests/083.out
index a24c6bfece..d3bea1b2f5 100644
--- a/tests/qemu-iotests/083.out
+++ b/tests/qemu-iotests/083.out
@@ -69,12 +69,12 @@ read failed: Input/output error
=== Check disconnect 4 reply ===
-read failed
+End of file
read failed: Input/output error
=== Check disconnect 8 reply ===
-read failed
+End of file
read failed: Input/output error
=== Check disconnect before data ===
--
2.11.1
- Re: [Qemu-devel] [PATCH 05/17] block/nbd-client: get rid of ssize_t, (continued)
Re: [Qemu-devel] [PATCH 05/17] block/nbd-client: get rid of ssize_t, Eric Blake, 2017/08/25
[Qemu-devel] [PATCH 01/17] nbd/client: fix nbd_opt_go, Vladimir Sementsov-Ogievskiy, 2017/08/04
[Qemu-devel] [PATCH 03/17] nbd/client: refactor nbd_receive_reply, Vladimir Sementsov-Ogievskiy, 2017/08/04
[Qemu-devel] [PATCH 08/17] block/nbd-client: rename nbd_recv_coroutines_enter_all, Vladimir Sementsov-Ogievskiy, 2017/08/04
[Qemu-devel] [PATCH 02/17] nbd/client: refactor nbd_read_eof,
Vladimir Sementsov-Ogievskiy <=
[Qemu-devel] [PATCH 06/17] block/nbd-client: fix nbd_read_reply_entry, Vladimir Sementsov-Ogievskiy, 2017/08/04
- Re: [Qemu-devel] [PATCH 06/17] block/nbd-client: fix nbd_read_reply_entry, Eric Blake, 2017/08/07
- Re: [Qemu-devel] [PATCH 06/17] block/nbd-client: fix nbd_read_reply_entry, Vladimir Sementsov-Ogievskiy, 2017/08/07
- Re: [Qemu-devel] [PATCH 06/17] block/nbd-client: fix nbd_read_reply_entry, Eric Blake, 2017/08/07
- Re: [Qemu-devel] [Qemu-block] [PATCH 06/17] block/nbd-client: fix nbd_read_reply_entry, Eric Blake, 2017/08/07
- Re: [Qemu-devel] [Qemu-block] [PATCH 06/17] block/nbd-client: fix nbd_read_reply_entry, Vladimir Sementsov-Ogievskiy, 2017/08/07
- Re: [Qemu-devel] [Qemu-block] [PATCH 06/17] block/nbd-client: fix nbd_read_reply_entry, Eric Blake, 2017/08/07