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author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2017-08-04 18:14:25 +0300 |
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committer | Eric Blake <eblake@redhat.com> | 2017-08-30 13:00:38 -0500 |
commit | ab01df1fe21c013d1fd9e3f4c782430741c7dd33 (patch) | |
tree | b65500fefd4e3f01cee811b6beaf87da40930b71 /nbd | |
parent | a0acf3a8f716946d7c425870bd05bc6dfe7667a2 (diff) | |
download | qemu-ab01df1fe21c013d1fd9e3f4c782430741c7dd33.zip qemu-ab01df1fe21c013d1fd9e3f4c782430741c7dd33.tar.gz qemu-ab01df1fe21c013d1fd9e3f4c782430741c7dd33.tar.bz2 |
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>
Diffstat (limited to 'nbd')
-rw-r--r-- | nbd/client.c | 5 | ||||
-rw-r--r-- | nbd/nbd-internal.h | 33 |
2 files changed, 24 insertions, 14 deletions
diff --git a/nbd/client.c b/nbd/client.c index f1c16b5..4556056 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 396ddb4..03549e3 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"); } |