[Qemu-devel] [PATCH v4 04/19] block: move aio initialization into a helper function

[Jeff Cody]

Move AIO initialization for raw-posix block driver into a helper function.

In addition to just code motion, the aio_ctx pointer is checked for NULL,
prior to calling laio_init(), to make sure laio_init() is only run once.

Signed-off-by: Jeff Cody 
---
 block/raw-posix.c | 53 +++--
 1 file changed, 35 insertions(+), 18 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 6be20b1..5981d04 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -185,6 +185,38 @@ static int raw_normalize_devicepath(const char **filename)
 }
 #endif
 
+#ifdef CONFIG_LINUX_AIO
+static int raw_set_aio(void **aio_ctx, int *use_aio, int bdrv_flags)
+{
+int ret = -1;
+assert(aio_ctx != NULL);
+assert(use_aio != NULL);
+/*
+ * Currently Linux do AIO only for files opened with O_DIRECT
+ * specified so check NOCACHE flag too
+ */
+if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
+  (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
+
+/* if non-NULL, laio_init() has already been run */
+if (*aio_ctx == NULL) {
+*aio_ctx = laio_init();
+if (!*aio_ctx) {
+goto error;
+}
+}
+*use_aio = 1;
+} else {
+*use_aio = 0;
+}
+
+ret = 0;
+
+error:
+return ret;
+}
+#endif
+
 static int raw_open_common(BlockDriverState *bs, const char *filename,
int bdrv_flags, int open_flags)
 {
@@ -240,25 +272,10 @@ static int raw_open_common(BlockDriverState *bs, const 
char *filename,
 }
 
 #ifdef CONFIG_LINUX_AIO
-/*
- * Currently Linux do AIO only for files opened with O_DIRECT
- * specified so check NOCACHE flag too
- */
-if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
-  (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
-
-s->aio_ctx = laio_init();
-if (!s->aio_ctx) {
-goto out_free_buf;
-}
-s->use_aio = 1;
-} else
-#endif
-{
-#ifdef CONFIG_LINUX_AIO
-s->use_aio = 0;
-#endif
+if (raw_set_aio(&s->aio_ctx, &s->use_aio, bdrv_flags)) {
+goto out_close;
 }
+#endif
 
 #ifdef CONFIG_XFS
 if (platform_test_xfs_fd(s->fd)) {
-- 
1.7.11.4

Re: [Qemu-devel] [PATCH v4 04/19] block: move aio initialization into a helper function

[Kevin Wolf]

Am 20.09.2012 21:13, schrieb Jeff Cody:
> Move AIO initialization for raw-posix block driver into a helper function.
> 
> In addition to just code motion, the aio_ctx pointer is checked for NULL,
> prior to calling laio_init(), to make sure laio_init() is only run once.
> 
> Signed-off-by: Jeff Cody 
> ---
>  block/raw-posix.c | 53 +++--
>  1 file changed, 35 insertions(+), 18 deletions(-)
> 
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 6be20b1..5981d04 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c

> @@ -240,25 +272,10 @@ static int raw_open_common(BlockDriverState *bs, const 
> char *filename,
>  }
>  
>  #ifdef CONFIG_LINUX_AIO
> -/*
> - * Currently Linux do AIO only for files opened with O_DIRECT
> - * specified so check NOCACHE flag too
> - */
> -if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
> -  (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
> -
> -s->aio_ctx = laio_init();
> -if (!s->aio_ctx) {
> -goto out_free_buf;
> -}
> -s->use_aio = 1;
> -} else
> -#endif
> -{
> -#ifdef CONFIG_LINUX_AIO
> -s->use_aio = 0;
> -#endif
> +if (raw_set_aio(&s->aio_ctx, &s->use_aio, bdrv_flags)) {
> +goto out_close;

This leaks s->aligned_buf. It's removed later in the series anyway, so
no big deal, but if you need to respin for other reasons, probably worth
fixing.

Kevin