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| author | Vladimir Sementsov-Ogievskiy | 2017-08-04 17:14:25 +0200 |
|---|---|---|
| committer | Eric Blake | 2017-08-30 20:00:38 +0200 |
| commit | ab01df1fe21c013d1fd9e3f4c782430741c7dd33 (patch) | |
| tree | b65500fefd4e3f01cee811b6beaf87da40930b71 | |
| parent | nbd/client: fix nbd_opt_go (diff) | |
| download | qemu-ab01df1fe21c013d1fd9e3f4c782430741c7dd33.tar.gz qemu-ab01df1fe21c013d1fd9e3f4c782430741c7dd33.tar.xz qemu-ab01df1fe21c013d1fd9e3f4c782430741c7dd33.zip | |
nbd/client: refactor nbd_read_eof
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 <vsementsov@virtuozzo.com>
Message-Id: <20170804151440.320927-3-vsementsov@virtuozzo.com>
[eblake: tweak function comments, rebase to test 083 enhancements]
Signed-off-by: Eric Blake <eblake@redhat.com>
| -rw-r--r-- | nbd/client.c | 5 | ||||
| -rw-r--r-- | nbd/nbd-internal.h | 33 | ||||
| -rw-r--r-- | tests/qemu-iotests/083.out | 8 |
3 files changed, 28 insertions, 18 deletions
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/nbd/nbd-internal.h b/nbd/nbd-internal.h index 396ddb4d3e..03549e3f39 100644 --- a/nbd/nbd-internal.h +++ b/nbd/nbd-internal.h @@ -77,21 +77,36 @@ #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) + * negative errno on failure (errp is set) */ -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); + + 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 +115,9 @@ 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/tests/qemu-iotests/083.out b/tests/qemu-iotests/083.out index a7fb081889..fb71b6f8ad 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 === @@ -180,12 +180,12 @@ 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 === |