[2/6] block: Make .bdrv_load_vmstate() vectored

Commit Message

Kevin Wolf June 10, 2016, 4:05 p.m. UTC

This brings it in line with .bdrv_save_vmstate().

Signed-off-by: Kevin Wolf <[e-mail]>
---
 block/io.c                | 26 +++++++++++++++++++++-----
 block/qcow2.c             |  6 +++---
 block/sheepdog.c          | 13 ++++++++++---
 include/block/block.h     |  1 +
 include/block/block_int.h |  4 ++--
 5 files changed, 37 insertions(+), 13 deletions(-)

Comments

Eric Blake June 10, 2016, 9:25 p.m. UTC | #1

On 06/10/2016 10:05 AM, Kevin Wolf wrote:
> This brings it in line with .bdrv_save_vmstate().
> 
> Signed-off-by: Kevin Wolf <[e-mail]>
> ---
>  block/io.c                | 26 +++++++++++++++++++++-----
>  block/qcow2.c             |  6 +++---
>  block/sheepdog.c          | 13 ++++++++++---
>  include/block/block.h     |  1 +
>  include/block/block_int.h |  4 ++--
>  5 files changed, 37 insertions(+), 13 deletions(-)
> 
> diff --git a/block/io.c b/block/io.c
> index 11510cf..602c7d3 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -1862,13 +1862,29 @@ int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
>  int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
>                        int64_t pos, int size)
>  {
> +    QEMUIOVector qiov;
> +    struct iovec iov = {
> +        .iov_base   = buf,
> +        .iov_len    = size,
> +    };
> +    int ret;

Dead variable.

> +
> +    qemu_iovec_init_external(&qiov, &iov, 1);
> +    return bdrv_readv_vmstate(bs, &qiov, pos);
> +}
> +
> +int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
> +{
>      BlockDriver *drv = bs->drv;
> -    if (!drv)
> +
> +    if (!drv) {
>          return -ENOMEDIUM;
> -    if (drv->bdrv_load_vmstate)
> -        return drv->bdrv_load_vmstate(bs, buf, pos, size);
> -    if (bs->file)
> -        return bdrv_load_vmstate(bs->file->bs, buf, pos, size);
> +    } else if (drv->bdrv_load_vmstate) {
> +        return drv->bdrv_load_vmstate(bs, qiov, pos);
> +    } else if (bs->file) {
> +        return bdrv_readv_vmstate(bs->file->bs, qiov, pos);
> +    }

Don't know that I would have used 'else if' after a return, but it's not
wrong, so no need to change.

With the dead 'ret' gone,
Reviewed-by: Eric Blake <[e-mail]>

Patch

diff --git a/block/io.c b/block/io.c
index 11510cf..602c7d3 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1862,13 +1862,29 @@  int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
                       int64_t pos, int size)
 {
+    QEMUIOVector qiov;
+    struct iovec iov = {
+        .iov_base   = buf,
+        .iov_len    = size,
+    };
+    int ret;
+
+    qemu_iovec_init_external(&qiov, &iov, 1);
+    return bdrv_readv_vmstate(bs, &qiov, pos);
+}
+
+int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
+{
     BlockDriver *drv = bs->drv;
-    if (!drv)
+
+    if (!drv) {
         return -ENOMEDIUM;
-    if (drv->bdrv_load_vmstate)
-        return drv->bdrv_load_vmstate(bs, buf, pos, size);
-    if (bs->file)
-        return bdrv_load_vmstate(bs->file->bs, buf, pos, size);
+    } else if (drv->bdrv_load_vmstate) {
+        return drv->bdrv_load_vmstate(bs, qiov, pos);
+    } else if (bs->file) {
+        return bdrv_readv_vmstate(bs->file->bs, qiov, pos);
+    }
+
     return -ENOTSUP;
 }
 
diff --git a/block/qcow2.c b/block/qcow2.c
index cb55e2d..72ae2bf 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2920,8 +2920,8 @@  static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
     return ret;
 }
 
-static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf,
-                              int64_t pos, int size)
+static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
+                              int64_t pos)
 {
     BDRVQcow2State *s = bs->opaque;
     bool zero_beyond_eof = bs->zero_beyond_eof;
@@ -2929,7 +2929,7 @@  static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 
     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
     bs->zero_beyond_eof = false;
-    ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size);
+    ret = bdrv_preadv(bs, qcow2_vm_state_offset(s) + pos, qiov);
     bs->zero_beyond_eof = zero_beyond_eof;
 
     return ret;
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 23fbace..ef5d044 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2784,12 +2784,19 @@  static int sd_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
     return ret;
 }
 
-static int sd_load_vmstate(BlockDriverState *bs, uint8_t *data,
-                           int64_t pos, int size)
+static int sd_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
+                           int64_t pos)
 {
     BDRVSheepdogState *s = bs->opaque;
+    void *buf;
+    int ret;
 
-    return do_load_save_vmstate(s, data, pos, size, 1);
+    buf = qemu_blockalign(bs, qiov->size);
+    ret = do_load_save_vmstate(s, buf, pos, qiov->size, 1);
+    qemu_iovec_from_buf(qiov, 0, buf, qiov->size);
+    qemu_vfree(buf);
+
+    return ret;
 }
 
 
diff --git a/include/block/block.h b/include/block/block.h
index aca7f23..a158575 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -428,6 +428,7 @@  void path_combine(char *dest, int dest_size,
                   const char *base_path,
                   const char *filename);
 
+int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
                       int64_t pos, int size);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 8a4963c..f9a32cc 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -226,8 +226,8 @@  struct BlockDriver {
 
     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
                              int64_t pos);
-    int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
-                             int64_t pos, int size);
+    int (*bdrv_load_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
+                             int64_t pos);
 
     int (*bdrv_change_backing_file)(BlockDriverState *bs,
         const char *backing_file, const char *backing_fmt);