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nbd: rename read_sync and friends

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Rename
  nbd_wr_syncv -> nbd_rwv
  read_sync -> nbd_read
  read_sync_eof -> nbd_read_eof
  write_sync -> nbd_write
  drop_sync -> nbd_drop

1. nbd_ prefix
   read_sync and write_sync are already shared, so it is good to have a
   namespace prefix. drop_sync will be shared, and read_sync_eof is
   related to read_sync, so let's rename them all.

2. _sync suffix
   _sync is related to the fact that nbd_wr_syncv doesn't return if a
   write to socket returns EAGAIN. The first implementation of
   nbd_wr_syncv (was wr_sync in 7a5ca8648b) just loops while getting
   EAGAIN, the current implementation yields in this case.
   Why we want to get rid of it:
   - it is normal for r/w functions to be synchronous, so having an
     additional suffix for it looks redundant (contrariwise, we have
     _aio suffix for async functions)
   - _sync suffix in block layer is used when function does flush (so
     using it for other thing is confusing a bit)
   - keep function names short after adding nbd_ prefix

3. for nbd_wr_syncv let's use more common notation 'rw'

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170602150150.258222-2-vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2017-06-02 18:01:39 +03:00 committed by Paolo Bonzini
parent 92229a57bb
commit d1fdf257d5
6 changed files with 48 additions and 56 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
block/nbd-client.c
View file

@ -144,8 +144,8 @@ static int nbd_co_send_request(BlockDriverState *bs,
qio_channel_set_cork(s->ioc, true);
rc = nbd_send_request(s->ioc, request);
if (rc >= 0) {
ret = nbd_wr_syncv(s->ioc, qiov->iov, qiov->niov, request->len,
false, NULL);
ret = nbd_rwv(s->ioc, qiov->iov, qiov->niov, request->len, false,
NULL);
if (ret != request->len) {
rc = -EIO;
}
@ -173,8 +173,8 @@ static void nbd_co_receive_reply(NBDClientSession *s,
reply->error = EIO;
} else {
if (qiov && reply->error == 0) {
ret = nbd_wr_syncv(s->ioc, qiov->iov, qiov->niov, request->len,
true, NULL);
ret = nbd_rwv(s->ioc, qiov->iov, qiov->niov, request->len, true,
NULL);
if (ret != request->len) {
reply->error = EIO;
}

8
include/block/nbd.h
View file

@ -123,12 +123,8 @@ enum {
* aren't overflowing some other buffer. */
#define NBD_MAX_NAME_SIZE 256
ssize_t nbd_wr_syncv(QIOChannel *ioc,
struct iovec *iov,
size_t niov,
size_t length,
bool do_read,
Error **errp);
ssize_t nbd_rwv(QIOChannel *ioc, struct iovec *iov, size_t niov, size_t length,
bool do_read, Error **errp);
int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
QCryptoTLSCreds *tlscreds, const char *hostname,
QIOChannel **outioc,

42
nbd/client.c
View file

@ -88,7 +88,7 @@ static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
/* Discard length bytes from channel. Return -errno on failure and 0 on
* success*/
static int drop_sync(QIOChannel *ioc, size_t size, Error **errp)
static int nbd_drop(QIOChannel *ioc, size_t size, Error **errp)
{
ssize_t ret = 0;
char small[1024];
@ -97,7 +97,7 @@ static int drop_sync(QIOChannel *ioc, size_t size, Error **errp)
buffer = sizeof(small) >= size ? small : g_malloc(MIN(65536, size));
while (size > 0) {
ssize_t count = MIN(65536, size);
ret = read_sync(ioc, buffer, MIN(65536, size), errp);
ret = nbd_read(ioc, buffer, MIN(65536, size), errp);
if (ret < 0) {
goto cleanup;
@ -135,12 +135,12 @@ static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt,
stl_be_p(&req.option, opt);
stl_be_p(&req.length, len);
if (write_sync(ioc, &req, sizeof(req), errp) < 0) {
if (nbd_write(ioc, &req, sizeof(req), errp) < 0) {
error_prepend(errp, "Failed to send option request header");
return -1;
}
if (len && write_sync(ioc, (char *) data, len, errp) < 0) {
if (len && nbd_write(ioc, (char *) data, len, errp) < 0) {
error_prepend(errp, "Failed to send option request data");
return -1;
}
@ -169,7 +169,7 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt,
nbd_opt_reply *reply, Error **errp)
{
QEMU_BUILD_BUG_ON(sizeof(*reply) != 20);
if (read_sync(ioc, reply, sizeof(*reply), errp) < 0) {
if (nbd_read(ioc, reply, sizeof(*reply), errp) < 0) {
error_prepend(errp, "failed to read option reply");
nbd_send_opt_abort(ioc);
return -1;
@ -218,7 +218,7 @@ static int nbd_handle_reply_err(QIOChannel *ioc, nbd_opt_reply *reply,
goto cleanup;
}
msg = g_malloc(reply->length + 1);
if (read_sync(ioc, msg, reply->length, errp) < 0) {
if (nbd_read(ioc, msg, reply->length, errp) < 0) {
error_prepend(errp, "failed to read option error message");
goto cleanup;
}
@ -320,7 +320,7 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
nbd_send_opt_abort(ioc);
return -1;
}
if (read_sync(ioc, &namelen, sizeof(namelen), errp) < 0) {
if (nbd_read(ioc, &namelen, sizeof(namelen), errp) < 0) {
error_prepend(errp, "failed to read option name length");
nbd_send_opt_abort(ioc);
return -1;
@ -333,7 +333,7 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
return -1;
}
if (namelen != strlen(want)) {
if (drop_sync(ioc, len, errp) < 0) {
if (nbd_drop(ioc, len, errp) < 0) {
error_prepend(errp, "failed to skip export name with wrong length");
nbd_send_opt_abort(ioc);
return -1;
@ -342,14 +342,14 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
}
assert(namelen < sizeof(name));
if (read_sync(ioc, name, namelen, errp) < 0) {
if (nbd_read(ioc, name, namelen, errp) < 0) {
error_prepend(errp, "failed to read export name");
nbd_send_opt_abort(ioc);
return -1;
}
name[namelen] = '\0';
len -= namelen;
if (drop_sync(ioc, len, errp) < 0) {
if (nbd_drop(ioc, len, errp) < 0) {
error_prepend(errp, "failed to read export description");
nbd_send_opt_abort(ioc);
return -1;
@ -476,7 +476,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
goto fail;
}
if (read_sync(ioc, buf, 8, errp) < 0) {
if (nbd_read(ioc, buf, 8, errp) < 0) {
error_prepend(errp, "Failed to read data");
goto fail;
}
@ -502,7 +502,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
goto fail;
}
if (read_sync(ioc, &magic, sizeof(magic), errp) < 0) {
if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {
error_prepend(errp, "Failed to read magic");
goto fail;
}
@ -514,7 +514,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
uint16_t globalflags;
bool fixedNewStyle = false;
if (read_sync(ioc, &globalflags, sizeof(globalflags), errp) < 0) {
if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) {
error_prepend(errp, "Failed to read server flags");
goto fail;
}
@ -532,7 +532,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
}
/* client requested flags */
clientflags = cpu_to_be32(clientflags);
if (write_sync(ioc, &clientflags, sizeof(clientflags), errp) < 0) {
if (nbd_write(ioc, &clientflags, sizeof(clientflags), errp) < 0) {
error_prepend(errp, "Failed to send clientflags field");
goto fail;
}
@ -570,13 +570,13 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
}
/* Read the response */
if (read_sync(ioc, &s, sizeof(s), errp) < 0) {
if (nbd_read(ioc, &s, sizeof(s), errp) < 0) {
error_prepend(errp, "Failed to read export length");
goto fail;
}
*size = be64_to_cpu(s);
if (read_sync(ioc, flags, sizeof(*flags), errp) < 0) {
if (nbd_read(ioc, flags, sizeof(*flags), errp) < 0) {
error_prepend(errp, "Failed to read export flags");
goto fail;
}
@ -593,14 +593,14 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
goto fail;
}
if (read_sync(ioc, &s, sizeof(s), errp) < 0) {
if (nbd_read(ioc, &s, sizeof(s), errp) < 0) {
error_prepend(errp, "Failed to read export length");
goto fail;
}
*size = be64_to_cpu(s);
TRACE("Size is %" PRIu64, *size);
if (read_sync(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
error_prepend(errp, "Failed to read export flags");
goto fail;
}
@ -616,7 +616,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
}
TRACE("Size is %" PRIu64 ", export flags %" PRIx16, *size, *flags);
if (zeroes && drop_sync(ioc, 124, errp) < 0) {
if (zeroes && nbd_drop(ioc, 124, errp) < 0) {
error_prepend(errp, "Failed to read reserved block");
goto fail;
}
@ -759,7 +759,7 @@ ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request)
stq_be_p(buf + 16, request->from);
stl_be_p(buf + 24, request->len);
return write_sync(ioc, buf, sizeof(buf), NULL);
return nbd_write(ioc, buf, sizeof(buf), NULL);
}
ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
@ -768,7 +768,7 @@ ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
uint32_t magic;
ssize_t ret;
ret = read_sync_eof(ioc, buf, sizeof(buf), errp);
ret = nbd_read_eof(ioc, buf, sizeof(buf), errp);
if (ret <= 0) {
return ret;
}

8
nbd/common.c
View file

@ -24,12 +24,8 @@
* 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,
size_t length,
bool do_read,
Error **errp)
ssize_t nbd_rwv(QIOChannel *ioc, struct iovec *iov, size_t niov, size_t length,
bool do_read, Error **errp)
{
ssize_t done = 0;
struct iovec *local_iov = g_new(struct iovec, niov);

26
nbd/nbd-internal.h
View file

@ -94,14 +94,14 @@
#define NBD_ENOSPC 28
#define NBD_ESHUTDOWN 108
/* read_sync_eof
/* 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 are no needs to call read_sync_eof
* qio_channel_readv() returns 0. So, there is no need to call nbd_read_eof
* iteratively.
*/
static inline ssize_t read_sync_eof(QIOChannel *ioc, void *buffer, size_t size,
Error **errp)
static inline ssize_t nbd_read_eof(QIOChannel *ioc, void *buffer, size_t size,
Error **errp)
{
struct iovec iov = { .iov_base = buffer, .iov_len = size };
/* Sockets are kept in blocking mode in the negotiation phase. After
@ -109,16 +109,16 @@ static inline ssize_t read_sync_eof(QIOChannel *ioc, void *buffer, size_t size,
* our request/reply. Synchronization is done with recv_coroutine, so
* that this is coroutine-safe.
*/
return nbd_wr_syncv(ioc, &iov, 1, size, true, errp);
return nbd_rwv(ioc, &iov, 1, size, true, errp);
}
/* read_sync
/* nbd_read
* Reads @size bytes from @ioc. Returns 0 on success.
*/
static inline int read_sync(QIOChannel *ioc, void *buffer, size_t size,
Error **errp)
static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size,
Error **errp)
{
ssize_t ret = read_sync_eof(ioc, buffer, size, errp);
ssize_t ret = nbd_read_eof(ioc, buffer, size, errp);
if (ret >= 0 && ret != size) {
ret = -EINVAL;
@ -128,15 +128,15 @@ static inline int read_sync(QIOChannel *ioc, void *buffer, size_t size,
return ret < 0 ? ret : 0;
}
/* write_sync
/* nbd_write
* Writes @size bytes to @ioc. Returns 0 on success.
*/
static inline int write_sync(QIOChannel *ioc, const void *buffer, size_t size,
Error **errp)
static inline int nbd_write(QIOChannel *ioc, const void *buffer, size_t size,
Error **errp)
{
struct iovec iov = { .iov_base = (void *) buffer, .iov_len = size };
ssize_t ret = nbd_wr_syncv(ioc, &iov, 1, size, false, errp);
ssize_t ret = nbd_rwv(ioc, &iov, 1, size, false, errp);
assert(ret < 0 || ret == size);

12
nbd/server.c
View file

@ -124,7 +124,7 @@ static int nbd_negotiate_read(QIOChannel *ioc, void *buffer, size_t size)
nbd_negotiate_continue,
qemu_coroutine_self(),
NULL);
ret = read_sync(ioc, buffer, size, NULL);
ret = nbd_read(ioc, buffer, size, NULL);
g_source_remove(watch);
return ret;
@ -142,7 +142,7 @@ static int nbd_negotiate_write(QIOChannel *ioc, const void *buffer, size_t size)
nbd_negotiate_continue,
qemu_coroutine_self(),
NULL);
ret = write_sync(ioc, buffer, size, NULL);
ret = nbd_write(ioc, buffer, size, NULL);
g_source_remove(watch);
return ret;
}
@ -694,7 +694,7 @@ static ssize_t nbd_receive_request(QIOChannel *ioc, NBDRequest *request)
uint32_t magic;
ssize_t ret;
ret = read_sync(ioc, buf, sizeof(buf), NULL);
ret = nbd_read(ioc, buf, sizeof(buf), NULL);
if (ret < 0) {
return ret;
}
@ -745,7 +745,7 @@ static ssize_t nbd_send_reply(QIOChannel *ioc, NBDReply *reply)
stl_be_p(buf + 4, reply->error);
stq_be_p(buf + 8, reply->handle);
return write_sync(ioc, buf, sizeof(buf), NULL);
return nbd_write(ioc, buf, sizeof(buf), NULL);
}
#define MAX_NBD_REQUESTS 16
@ -1048,7 +1048,7 @@ static ssize_t nbd_co_send_reply(NBDRequestData *req, NBDReply *reply,
qio_channel_set_cork(client->ioc, true);
rc = nbd_send_reply(client->ioc, reply);
if (rc >= 0) {
ret = write_sync(client->ioc, req->data, len, NULL);
ret = nbd_write(client->ioc, req->data, len, NULL);
if (ret < 0) {
rc = -EIO;
}
@ -1123,7 +1123,7 @@ static ssize_t nbd_co_receive_request(NBDRequestData *req,
if (request->type == NBD_CMD_WRITE) {
TRACE("Reading %" PRIu32 " byte(s)", request->len);
if (read_sync(client->ioc, req->data, request->len, NULL) < 0) {
if (nbd_read(client->ioc, req->data, request->len, NULL) < 0) {
LOG("reading from socket failed");
rc = -EIO;
goto out;