Re: [Qemu-devel] [PATCH 4/5] migration: size_t'ify some of qemu-file

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

On 2015/8/13 18:51, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> This is a start on using size_t more in qemu-file and friends;
> it fixes up QEMUFilePutBufferFunc and QEMUFileGetBufferFunc
> to take size_t lengths and return ssize_t return values (like read(2))
> and fixes up all the different implementations of them.
>
> Note that I've not yet followed this deeply into bdrv_ implementations.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---

Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>

>   include/migration/qemu-file.h |  8 ++++----
>   migration/qemu-file-buf.c     |  7 ++++---
>   migration/qemu-file-stdio.c   | 11 ++++++-----
>   migration/qemu-file-unix.c    |  6 ++++--
>   migration/rdma.c              | 13 +++++++------
>   migration/savevm.c            |  7 ++++---
>   trace-events                  |  2 +-
>   7 files changed, 30 insertions(+), 24 deletions(-)
>
> diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
> index ea49f33..e1e2bab 100644
> --- a/include/migration/qemu-file.h
> +++ b/include/migration/qemu-file.h
> @@ -31,15 +31,15 @@
>    * The pos argument can be ignored if the file is only being used for
>    * streaming.  The handler should try to write all of the data it can.
>    */
> -typedef int (QEMUFilePutBufferFunc)(void *opaque, const uint8_t *buf,
> -                                    int64_t pos, int size);
> +typedef ssize_t (QEMUFilePutBufferFunc)(void *opaque, const uint8_t *buf,
> +                                        int64_t pos, size_t size);
>
>   /* Read a chunk of data from a file at the given position.  The pos argument
>    * can be ignored if the file is only be used for streaming.  The number of
>    * bytes actually read should be returned.
>    */
> -typedef int (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
> -                                    int64_t pos, int size);
> +typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
> +                                        int64_t pos, size_t size);
>
>   /* Close a file
>    *
> diff --git a/migration/qemu-file-buf.c b/migration/qemu-file-buf.c
> index 2de9330..1d9528e 100644
> --- a/migration/qemu-file-buf.c
> +++ b/migration/qemu-file-buf.c
> @@ -372,7 +372,8 @@ typedef struct QEMUBuffer {
>       bool qsb_allocated;
>   } QEMUBuffer;
>
> -static int buf_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
> +static ssize_t buf_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
> +                              size_t size)
>   {
>       QEMUBuffer *s = opaque;
>       ssize_t len = qsb_get_length(s->qsb) - pos;
> @@ -387,8 +388,8 @@ static int buf_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
>       return qsb_get_buffer(s->qsb, pos, len, buf);
>   }
>
> -static int buf_put_buffer(void *opaque, const uint8_t *buf,
> -                          int64_t pos, int size)
> +static ssize_t buf_put_buffer(void *opaque, const uint8_t *buf,
> +                              int64_t pos, size_t size)
>   {
>       QEMUBuffer *s = opaque;
>
> diff --git a/migration/qemu-file-stdio.c b/migration/qemu-file-stdio.c
> index 285068b..dc91137 100644
> --- a/migration/qemu-file-stdio.c
> +++ b/migration/qemu-file-stdio.c
> @@ -37,11 +37,11 @@ static int stdio_get_fd(void *opaque)
>       return fileno(s->stdio_file);
>   }
>
> -static int stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos,
> -                            int size)
> +static ssize_t stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos,
> +                                size_t size)
>   {
>       QEMUFileStdio *s = opaque;
> -    int res;
> +    size_t res;
>
>       res = fwrite(buf, 1, size, s->stdio_file);
>
> @@ -51,11 +51,12 @@ static int stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos,
>       return res;
>   }
>
> -static int stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
> +static ssize_t stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
> +                                size_t size)
>   {
>       QEMUFileStdio *s = opaque;
>       FILE *fp = s->stdio_file;
> -    int bytes;
> +    ssize_t bytes;
>
>       for (;;) {
>           clearerr(fp);
> diff --git a/migration/qemu-file-unix.c b/migration/qemu-file-unix.c
> index bfbc086..adfe91a 100644
> --- a/migration/qemu-file-unix.c
> +++ b/migration/qemu-file-unix.c
> @@ -54,7 +54,8 @@ static int socket_get_fd(void *opaque)
>       return s->fd;
>   }
>
> -static int socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
> +static ssize_t socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
> +                                 size_t size)
>   {
>       QEMUFileSocket *s = opaque;
>       ssize_t len;
> @@ -138,7 +139,8 @@ static ssize_t unix_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
>       return total;
>   }
>
> -static int unix_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
> +static ssize_t unix_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
> +                              size_t size)
>   {
>       QEMUFileSocket *s = opaque;
>       ssize_t len;
> diff --git a/migration/rdma.c b/migration/rdma.c
> index 74876fd..fd430c7 100644
> --- a/migration/rdma.c
> +++ b/migration/rdma.c
> @@ -2519,8 +2519,8 @@ static void *qemu_rdma_data_init(const char *host_port, Error **errp)
>    * SEND messages for control only.
>    * VM's ram is handled with regular RDMA messages.
>    */
> -static int qemu_rdma_put_buffer(void *opaque, const uint8_t *buf,
> -                                int64_t pos, int size)
> +static ssize_t qemu_rdma_put_buffer(void *opaque, const uint8_t *buf,
> +                                    int64_t pos, size_t size)
>   {
>       QEMUFileRDMA *r = opaque;
>       QEMUFile *f = r->file;
> @@ -2547,7 +2547,8 @@ static int qemu_rdma_put_buffer(void *opaque, const uint8_t *buf,
>           r->len = MIN(remaining, RDMA_SEND_INCREMENT);
>           remaining -= r->len;
>
> -        head.len = r->len;
> +        /* Guaranteed to fit due to RDMA_SEND_INCREMENT MIN above */
> +        head.len = (uint32_t)r->len;
>           head.type = RDMA_CONTROL_QEMU_FILE;
>
>           ret = qemu_rdma_exchange_send(rdma, &head, data, NULL, NULL, NULL);
> @@ -2564,7 +2565,7 @@ static int qemu_rdma_put_buffer(void *opaque, const uint8_t *buf,
>   }
>
>   static size_t qemu_rdma_fill(RDMAContext *rdma, uint8_t *buf,
> -                             int size, int idx)
> +                             size_t size, int idx)
>   {
>       size_t len = 0;
>
> @@ -2585,8 +2586,8 @@ static size_t qemu_rdma_fill(RDMAContext *rdma, uint8_t *buf,
>    * RDMA links don't use bytestreams, so we have to
>    * return bytes to QEMUFile opportunistically.
>    */
> -static int qemu_rdma_get_buffer(void *opaque, uint8_t *buf,
> -                                int64_t pos, int size)
> +static ssize_t qemu_rdma_get_buffer(void *opaque, uint8_t *buf,
> +                                    int64_t pos, size_t size)
>   {
>       QEMUFileRDMA *r = opaque;
>       RDMAContext *rdma = r->rdma;
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 6071215..1bd8827 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -138,14 +138,15 @@ static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
>       return qiov.size;
>   }
>
> -static int block_put_buffer(void *opaque, const uint8_t *buf,
> -                           int64_t pos, int size)
> +static ssize_t block_put_buffer(void *opaque, const uint8_t *buf,
> +                                int64_t pos, size_t size)
>   {
>       bdrv_save_vmstate(opaque, buf, pos, size);
>       return size;
>   }
>
> -static int block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
> +static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
> +                                size_t size)
>   {
>       return bdrv_load_vmstate(opaque, buf, pos, size);
>   }
> diff --git a/trace-events b/trace-events
> index 1509e5b..1e7d9b6 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1428,7 +1428,7 @@ qemu_rdma_exchange_get_response_none(const char *desc, int type) "Surprise: got
>   qemu_rdma_exchange_send_issue_callback(void) ""
>   qemu_rdma_exchange_send_waiting(const char *desc) "Waiting for response %s"
>   qemu_rdma_exchange_send_received(const char *desc) "Response %s received."
> -qemu_rdma_fill(int64_t control_len, int size) "RDMA %" PRId64 " of %d bytes already in buffer"
> +qemu_rdma_fill(size_t control_len, size_t size) "RDMA %zd of %zd bytes already in buffer"
>   qemu_rdma_init_ram_blocks(int blocks) "Allocated %d local ram block structures"
>   qemu_rdma_poll_recv(const char *compstr, int64_t comp, int64_t id, int sent) "completion %s #%" PRId64 " received (%" PRId64 ") left %d"
>   qemu_rdma_poll_write(const char *compstr, int64_t comp, int left, uint64_t block, uint64_t chunk, void *local, void *remote) "completions %s (%" PRId64 ") left %d, block %" PRIu64 ", chunk: %" PRIu64 " %p %p"
>