* [Qemu-devel] [PATCH v3 0/2] linux-aio: fix two NULL pointer dereferences failure paths
@ 2018-06-21 22:21 Nishanth Aravamudan
2018-06-21 22:21 ` [Qemu-devel] [PATCH v3 1/2] linux-aio: properly bubble up errors from initialization Nishanth Aravamudan
2018-06-21 22:21 ` [Qemu-devel] [PATCH v3 2/2] block/file-posix: reconfigure aio on iothread start Nishanth Aravamudan
0 siblings, 2 replies; 8+ messages in thread
From: Nishanth Aravamudan @ 2018-06-21 22:21 UTC (permalink / raw)
To: naravamudan
Cc: Eric Blake, Kevin Wolf, John Snow, Max Reitz, Stefan Hajnoczi,
Fam Zheng, Paolo Bonzini, qemu-block, qemu-devel
laio_init() can fail for a couple of reasons, which will lead to a NULL
pointer dereference in laio_attach_aio_context(), called from
aio_get_linux_aio().
Test case 1:
Set /proc/sys/fs/max-aio-nr to 0. Start a guest with an aio=native
disk.
Result: laio_init() returns NULL due to not being able to allocate
any AIO contexts. This NULL is assigned to ctx->linux_aio and
dereferenced in aio_get_linux_aio.
Test case 2:
Set /proc/sys/fs/max-aio-nr to 128. Start a guest with an aio=native
disk and one in-use I/O thread.
Result: laio_init() returns NULL due to not being able to allocate
additional AIO contexts for the I/O thread. This NULL is assigned to
ctx->linux_aio and dereferenced in aio_get_linux_aio.
Thanks to Jon Snow, Eric Blake and Kevin Wolf for review comments on v1
and v2.
Nishanth Aravamudan (2):
linux-aio: properly bubble up errors from initialization
file-posix: reconfigure aio on iothread start
block/file-posix.c | 33 ++++++++++++++++++++++++++++-----
block/linux-aio.c | 15 ++++++++++-----
include/block/aio.h | 3 +++
include/block/raw-aio.h | 2 +-
stubs/linux-aio.c | 2 +-
util/async.c | 16 +++++++++++++---
6 files changed, 56 insertions(+), 15 deletions(-)
--
2.17.1
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH v3 1/2] linux-aio: properly bubble up errors from initialization
2018-06-21 22:21 [Qemu-devel] [PATCH v3 0/2] linux-aio: fix two NULL pointer dereferences failure paths Nishanth Aravamudan
@ 2018-06-21 22:21 ` Nishanth Aravamudan
2018-06-22 2:21 ` Fam Zheng
2018-06-21 22:21 ` [Qemu-devel] [PATCH v3 2/2] block/file-posix: reconfigure aio on iothread start Nishanth Aravamudan
1 sibling, 1 reply; 8+ messages in thread
From: Nishanth Aravamudan @ 2018-06-21 22:21 UTC (permalink / raw)
To: naravamudan
Cc: Eric Blake, Kevin Wolf, John Snow, Max Reitz, Stefan Hajnoczi,
Fam Zheng, Paolo Bonzini, qemu-block, qemu-devel
laio_init() can fail for a couple of reasons, which will lead to a NULL
pointer dereference in laio_attach_aio_context().
To solve this, add a aio_setup_linux_aio() function which is called
early in raw_open_common. If this fails, propagate the error up. The
signature of aio_get_linux_aio() was not modified, because it seems
preferable to return the actual errno from the possible failing
initialization calls.
Add an assert that aio_get_linux_aio() cannot return NULL.
Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com>
---
Changes from v2 -> v3 (thanks to Eric Blake and Kevin Wolf for review):
Use a boolean false rather than 0 in assignment to use_linux_aio.
Drop ending '.' from error_report() calls.
Fix typo in commit message (propogates -> propagates).
Move aio_setup_linux_aio call to raw_open_common.
Changes from v1 -> v2 (thanks to Kevin Wolf for review):
Rather than affect virtio-scsi/blk at all, make all the changes internal
to file-posix.c. Thanks to Kevin Wolf for the suggested change.
block/file-posix.c | 17 ++++++++++++-----
block/linux-aio.c | 15 ++++++++++-----
include/block/aio.h | 3 +++
include/block/raw-aio.h | 2 +-
stubs/linux-aio.c | 2 +-
util/async.c | 16 +++++++++++++---
6 files changed, 40 insertions(+), 15 deletions(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index 07bb061fe4..6a1714d4a8 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -545,11 +545,18 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
#ifdef CONFIG_LINUX_AIO
/* Currently Linux does AIO only for files opened with O_DIRECT */
- if (s->use_linux_aio && !(s->open_flags & O_DIRECT)) {
- error_setg(errp, "aio=native was specified, but it requires "
- "cache.direct=on, which was not specified.");
- ret = -EINVAL;
- goto fail;
+ if (s->use_linux_aio) {
+ if (!(s->open_flags & O_DIRECT)) {
+ error_setg(errp, "aio=native was specified, but it requires "
+ "cache.direct=on, which was not specified.");
+ ret = -EINVAL;
+ goto fail;
+ }
+ ret = aio_setup_linux_aio(bdrv_get_aio_context(bs));
+ if (ret != 0) {
+ error_setg(errp, "Unable to setup native AIO context.");
+ goto fail;
+ }
}
#else
if (s->use_linux_aio) {
diff --git a/block/linux-aio.c b/block/linux-aio.c
index 88b8d55ec7..4d799f85fe 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -470,28 +470,33 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
qemu_laio_poll_cb);
}
-LinuxAioState *laio_init(void)
+int laio_init(LinuxAioState **linux_aio)
{
+ int rc;
LinuxAioState *s;
s = g_malloc0(sizeof(*s));
- if (event_notifier_init(&s->e, false) < 0) {
+ rc = event_notifier_init(&s->e, false);
+ if (rc < 0) {
goto out_free_state;
}
- if (io_setup(MAX_EVENTS, &s->ctx) != 0) {
+ rc = io_setup(MAX_EVENTS, &s->ctx);
+ if (rc != 0) {
goto out_close_efd;
}
ioq_init(&s->io_q);
- return s;
+ *linux_aio = s;
+ return 0;
out_close_efd:
event_notifier_cleanup(&s->e);
out_free_state:
g_free(s);
- return NULL;
+ *linux_aio = NULL;
+ return rc;
}
void laio_cleanup(LinuxAioState *s)
diff --git a/include/block/aio.h b/include/block/aio.h
index ae6f354e6c..8900516ac5 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -381,6 +381,9 @@ GSource *aio_get_g_source(AioContext *ctx);
/* Return the ThreadPool bound to this AioContext */
struct ThreadPool *aio_get_thread_pool(AioContext *ctx);
+/* Setup the LinuxAioState bound to this AioContext */
+int aio_setup_linux_aio(AioContext *ctx);
+
/* Return the LinuxAioState bound to this AioContext */
struct LinuxAioState *aio_get_linux_aio(AioContext *ctx);
diff --git a/include/block/raw-aio.h b/include/block/raw-aio.h
index 0e717fd475..81b90e5fc6 100644
--- a/include/block/raw-aio.h
+++ b/include/block/raw-aio.h
@@ -43,7 +43,7 @@
/* linux-aio.c - Linux native implementation */
#ifdef CONFIG_LINUX_AIO
typedef struct LinuxAioState LinuxAioState;
-LinuxAioState *laio_init(void);
+int laio_init(LinuxAioState **linux_aio);
void laio_cleanup(LinuxAioState *s);
int coroutine_fn laio_co_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
uint64_t offset, QEMUIOVector *qiov, int type);
diff --git a/stubs/linux-aio.c b/stubs/linux-aio.c
index ed47bd443c..88ab927e35 100644
--- a/stubs/linux-aio.c
+++ b/stubs/linux-aio.c
@@ -21,7 +21,7 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
abort();
}
-LinuxAioState *laio_init(void)
+int laio_init(LinuxAioState **linux_aio)
{
abort();
}
diff --git a/util/async.c b/util/async.c
index 03f62787f2..ae88c931d0 100644
--- a/util/async.c
+++ b/util/async.c
@@ -323,12 +323,22 @@ ThreadPool *aio_get_thread_pool(AioContext *ctx)
}
#ifdef CONFIG_LINUX_AIO
-LinuxAioState *aio_get_linux_aio(AioContext *ctx)
+int aio_setup_linux_aio(AioContext *ctx)
{
+ int rc;
+ rc = 0;
if (!ctx->linux_aio) {
- ctx->linux_aio = laio_init();
- laio_attach_aio_context(ctx->linux_aio, ctx);
+ rc = laio_init(&ctx->linux_aio);
+ if (rc == 0) {
+ laio_attach_aio_context(ctx->linux_aio, ctx);
+ }
}
+ return rc;
+}
+
+LinuxAioState *aio_get_linux_aio(AioContext *ctx)
+{
+ assert(ctx->linux_aio);
return ctx->linux_aio;
}
#endif
--
2.17.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH v3 2/2] block/file-posix: reconfigure aio on iothread start
2018-06-21 22:21 [Qemu-devel] [PATCH v3 0/2] linux-aio: fix two NULL pointer dereferences failure paths Nishanth Aravamudan
2018-06-21 22:21 ` [Qemu-devel] [PATCH v3 1/2] linux-aio: properly bubble up errors from initialization Nishanth Aravamudan
@ 2018-06-21 22:21 ` Nishanth Aravamudan
2018-06-22 2:25 ` Fam Zheng
1 sibling, 1 reply; 8+ messages in thread
From: Nishanth Aravamudan @ 2018-06-21 22:21 UTC (permalink / raw)
To: naravamudan
Cc: Eric Blake, Kevin Wolf, John Snow, Max Reitz, Stefan Hajnoczi,
Fam Zheng, Paolo Bonzini, qemu-block, qemu-devel
When the AioContext changes, we need to associate a LinuxAioState with
the new AioContext. Use the bdrv_attach_aio_context callback and call
the new aio_setup_linux_aio(), which will allocate a new AioContext if
needed, and return errors on failures. If it fails for any reason,
fallback to threaded AIO with an error message, as the device is already
in-use by the guest.
Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com>
---
Note this patch didn't exist in v2, but is a result of feedback to that
posting.
block/file-posix.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/block/file-posix.c b/block/file-posix.c
index 6a1714d4a8..ce24950acf 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1730,6 +1730,21 @@ static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
return paio_submit(bs, s->fd, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
}
+static void raw_aio_attach_aio_context(BlockDriverState *bs,
+ AioContext *new_context)
+{
+#ifdef CONFIG_LINUX_AIO
+ BDRVRawState *s = bs->opaque;
+ if (s->use_linux_aio) {
+ if (aio_setup_linux_aio(new_context) != 0) {
+ error_report("Unable to use native AIO, falling back to "
+ "thread pool");
+ s->use_linux_aio = false;
+ }
+ }
+#endif
+}
+
static void raw_close(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
@@ -2608,6 +2623,7 @@ BlockDriver bdrv_file = {
.bdrv_refresh_limits = raw_refresh_limits,
.bdrv_io_plug = raw_aio_plug,
.bdrv_io_unplug = raw_aio_unplug,
+ .bdrv_attach_aio_context = raw_aio_attach_aio_context,
.bdrv_truncate = raw_truncate,
.bdrv_getlength = raw_getlength,
--
2.17.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH v3 1/2] linux-aio: properly bubble up errors from initialization
2018-06-21 22:21 ` [Qemu-devel] [PATCH v3 1/2] linux-aio: properly bubble up errors from initialization Nishanth Aravamudan
@ 2018-06-22 2:21 ` Fam Zheng
2018-06-22 17:12 ` Nishanth Aravamudan
0 siblings, 1 reply; 8+ messages in thread
From: Fam Zheng @ 2018-06-22 2:21 UTC (permalink / raw)
To: Nishanth Aravamudan
Cc: Eric Blake, Kevin Wolf, John Snow, Max Reitz, Stefan Hajnoczi,
Paolo Bonzini, qemu-block, qemu-devel
On Thu, 06/21 15:21, Nishanth Aravamudan wrote:
> laio_init() can fail for a couple of reasons, which will lead to a NULL
> pointer dereference in laio_attach_aio_context().
>
> To solve this, add a aio_setup_linux_aio() function which is called
> early in raw_open_common. If this fails, propagate the error up. The
> signature of aio_get_linux_aio() was not modified, because it seems
> preferable to return the actual errno from the possible failing
> initialization calls.
>
> Add an assert that aio_get_linux_aio() cannot return NULL.
>
> Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com>
> ---
> Changes from v2 -> v3 (thanks to Eric Blake and Kevin Wolf for review):
>
> Use a boolean false rather than 0 in assignment to use_linux_aio.
> Drop ending '.' from error_report() calls.
> Fix typo in commit message (propogates -> propagates).
> Move aio_setup_linux_aio call to raw_open_common.
>
> Changes from v1 -> v2 (thanks to Kevin Wolf for review):
>
> Rather than affect virtio-scsi/blk at all, make all the changes internal
> to file-posix.c. Thanks to Kevin Wolf for the suggested change.
>
> block/file-posix.c | 17 ++++++++++++-----
> block/linux-aio.c | 15 ++++++++++-----
> include/block/aio.h | 3 +++
> include/block/raw-aio.h | 2 +-
> stubs/linux-aio.c | 2 +-
> util/async.c | 16 +++++++++++++---
> 6 files changed, 40 insertions(+), 15 deletions(-)
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 07bb061fe4..6a1714d4a8 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -545,11 +545,18 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
>
> #ifdef CONFIG_LINUX_AIO
> /* Currently Linux does AIO only for files opened with O_DIRECT */
> - if (s->use_linux_aio && !(s->open_flags & O_DIRECT)) {
> - error_setg(errp, "aio=native was specified, but it requires "
> - "cache.direct=on, which was not specified.");
> - ret = -EINVAL;
> - goto fail;
> + if (s->use_linux_aio) {
> + if (!(s->open_flags & O_DIRECT)) {
> + error_setg(errp, "aio=native was specified, but it requires "
> + "cache.direct=on, which was not specified.");
> + ret = -EINVAL;
> + goto fail;
> + }
> + ret = aio_setup_linux_aio(bdrv_get_aio_context(bs));
> + if (ret != 0) {
> + error_setg(errp, "Unable to setup native AIO context.");
> + goto fail;
> + }
> }
> #else
> if (s->use_linux_aio) {
> diff --git a/block/linux-aio.c b/block/linux-aio.c
> index 88b8d55ec7..4d799f85fe 100644
> --- a/block/linux-aio.c
> +++ b/block/linux-aio.c
> @@ -470,28 +470,33 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
> qemu_laio_poll_cb);
> }
>
> -LinuxAioState *laio_init(void)
> +int laio_init(LinuxAioState **linux_aio)
> {
> + int rc;
> LinuxAioState *s;
>
> s = g_malloc0(sizeof(*s));
> - if (event_notifier_init(&s->e, false) < 0) {
> + rc = event_notifier_init(&s->e, false);
> + if (rc < 0) {
It would be nice if the error message could distinguish this error...
> goto out_free_state;
> }
>
> - if (io_setup(MAX_EVENTS, &s->ctx) != 0) {
> + rc = io_setup(MAX_EVENTS, &s->ctx);
> + if (rc != 0) {
... from this one. And it also makes sense to propagate the errno back with
error_setg_errno.
To do this, add an "Error **errp" parameter to the function and you can keep the
return type (LinuxAioState *).
> goto out_close_efd;
> }
>
> ioq_init(&s->io_q);
>
> - return s;
> + *linux_aio = s;
> + return 0;
>
> out_close_efd:
> event_notifier_cleanup(&s->e);
> out_free_state:
> g_free(s);
> - return NULL;
> + *linux_aio = NULL;
> + return rc;
> }
>
> void laio_cleanup(LinuxAioState *s)
> diff --git a/include/block/aio.h b/include/block/aio.h
> index ae6f354e6c..8900516ac5 100644
> --- a/include/block/aio.h
> +++ b/include/block/aio.h
> @@ -381,6 +381,9 @@ GSource *aio_get_g_source(AioContext *ctx);
> /* Return the ThreadPool bound to this AioContext */
> struct ThreadPool *aio_get_thread_pool(AioContext *ctx);
>
> +/* Setup the LinuxAioState bound to this AioContext */
> +int aio_setup_linux_aio(AioContext *ctx);
And this will then need "Error **errp" as well.
> +
> /* Return the LinuxAioState bound to this AioContext */
> struct LinuxAioState *aio_get_linux_aio(AioContext *ctx);
>
> diff --git a/include/block/raw-aio.h b/include/block/raw-aio.h
> index 0e717fd475..81b90e5fc6 100644
> --- a/include/block/raw-aio.h
> +++ b/include/block/raw-aio.h
> @@ -43,7 +43,7 @@
> /* linux-aio.c - Linux native implementation */
> #ifdef CONFIG_LINUX_AIO
> typedef struct LinuxAioState LinuxAioState;
> -LinuxAioState *laio_init(void);
> +int laio_init(LinuxAioState **linux_aio);
> void laio_cleanup(LinuxAioState *s);
> int coroutine_fn laio_co_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
> uint64_t offset, QEMUIOVector *qiov, int type);
> diff --git a/stubs/linux-aio.c b/stubs/linux-aio.c
> index ed47bd443c..88ab927e35 100644
> --- a/stubs/linux-aio.c
> +++ b/stubs/linux-aio.c
> @@ -21,7 +21,7 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
> abort();
> }
>
> -LinuxAioState *laio_init(void)
> +int laio_init(LinuxAioState **linux_aio)
> {
> abort();
> }
> diff --git a/util/async.c b/util/async.c
> index 03f62787f2..ae88c931d0 100644
> --- a/util/async.c
> +++ b/util/async.c
> @@ -323,12 +323,22 @@ ThreadPool *aio_get_thread_pool(AioContext *ctx)
> }
>
> #ifdef CONFIG_LINUX_AIO
> -LinuxAioState *aio_get_linux_aio(AioContext *ctx)
> +int aio_setup_linux_aio(AioContext *ctx)
> {
> + int rc;
> + rc = 0;
> if (!ctx->linux_aio) {
> - ctx->linux_aio = laio_init();
> - laio_attach_aio_context(ctx->linux_aio, ctx);
> + rc = laio_init(&ctx->linux_aio);
> + if (rc == 0) {
> + laio_attach_aio_context(ctx->linux_aio, ctx);
> + }
> }
> + return rc;
> +}
> +
> +LinuxAioState *aio_get_linux_aio(AioContext *ctx)
> +{
> + assert(ctx->linux_aio);
> return ctx->linux_aio;
> }
> #endif
> --
> 2.17.1
>
Fam
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH v3 2/2] block/file-posix: reconfigure aio on iothread start
2018-06-21 22:21 ` [Qemu-devel] [PATCH v3 2/2] block/file-posix: reconfigure aio on iothread start Nishanth Aravamudan
@ 2018-06-22 2:25 ` Fam Zheng
2018-06-22 9:02 ` Kevin Wolf
0 siblings, 1 reply; 8+ messages in thread
From: Fam Zheng @ 2018-06-22 2:25 UTC (permalink / raw)
To: Nishanth Aravamudan
Cc: Eric Blake, Kevin Wolf, John Snow, Max Reitz, Stefan Hajnoczi,
Paolo Bonzini, qemu-block, qemu-devel
On Thu, 06/21 15:21, Nishanth Aravamudan wrote:
> When the AioContext changes, we need to associate a LinuxAioState with
> the new AioContext. Use the bdrv_attach_aio_context callback and call
> the new aio_setup_linux_aio(), which will allocate a new AioContext if
> needed, and return errors on failures. If it fails for any reason,
> fallback to threaded AIO with an error message, as the device is already
> in-use by the guest.
>
> Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com>
> ---
> Note this patch didn't exist in v2, but is a result of feedback to that
> posting.
This should be squashed into patch 1, no?
Fam
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH v3 2/2] block/file-posix: reconfigure aio on iothread start
2018-06-22 2:25 ` Fam Zheng
@ 2018-06-22 9:02 ` Kevin Wolf
2018-06-22 17:12 ` Nishanth Aravamudan
0 siblings, 1 reply; 8+ messages in thread
From: Kevin Wolf @ 2018-06-22 9:02 UTC (permalink / raw)
To: Fam Zheng
Cc: Nishanth Aravamudan, Eric Blake, John Snow, Max Reitz,
Stefan Hajnoczi, Paolo Bonzini, qemu-block, qemu-devel
Am 22.06.2018 um 04:25 hat Fam Zheng geschrieben:
> On Thu, 06/21 15:21, Nishanth Aravamudan wrote:
> > When the AioContext changes, we need to associate a LinuxAioState with
> > the new AioContext. Use the bdrv_attach_aio_context callback and call
> > the new aio_setup_linux_aio(), which will allocate a new AioContext if
> > needed, and return errors on failures. If it fails for any reason,
> > fallback to threaded AIO with an error message, as the device is already
> > in-use by the guest.
> >
> > Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com>
> > ---
> > Note this patch didn't exist in v2, but is a result of feedback to that
> > posting.
>
> This should be squashed into patch 1, no?
Yes, without it, patch 1 is incorrect. Specifically, at least the
assertion in aio_get_linux_aio() won't hold true without it.
Kevin
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH v3 1/2] linux-aio: properly bubble up errors from initialization
2018-06-22 2:21 ` Fam Zheng
@ 2018-06-22 17:12 ` Nishanth Aravamudan
0 siblings, 0 replies; 8+ messages in thread
From: Nishanth Aravamudan @ 2018-06-22 17:12 UTC (permalink / raw)
To: Fam Zheng
Cc: Eric Blake, Kevin Wolf, John Snow, Max Reitz, Stefan Hajnoczi,
Paolo Bonzini, qemu-block, qemu-devel
On 22.06.2018 [10:21:19 +0800], Fam Zheng wrote:
> On Thu, 06/21 15:21, Nishanth Aravamudan wrote:
> > laio_init() can fail for a couple of reasons, which will lead to a NULL
> > pointer dereference in laio_attach_aio_context().
> >
> > To solve this, add a aio_setup_linux_aio() function which is called
> > early in raw_open_common. If this fails, propagate the error up. The
> > signature of aio_get_linux_aio() was not modified, because it seems
> > preferable to return the actual errno from the possible failing
> > initialization calls.
> >
> > Add an assert that aio_get_linux_aio() cannot return NULL.
> >
> > Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com>
> > ---
> > Changes from v2 -> v3 (thanks to Eric Blake and Kevin Wolf for review):
> >
> > Use a boolean false rather than 0 in assignment to use_linux_aio.
> > Drop ending '.' from error_report() calls.
> > Fix typo in commit message (propogates -> propagates).
> > Move aio_setup_linux_aio call to raw_open_common.
> >
> > Changes from v1 -> v2 (thanks to Kevin Wolf for review):
> >
> > Rather than affect virtio-scsi/blk at all, make all the changes internal
> > to file-posix.c. Thanks to Kevin Wolf for the suggested change.
> >
> > block/file-posix.c | 17 ++++++++++++-----
> > block/linux-aio.c | 15 ++++++++++-----
> > include/block/aio.h | 3 +++
> > include/block/raw-aio.h | 2 +-
> > stubs/linux-aio.c | 2 +-
> > util/async.c | 16 +++++++++++++---
> > 6 files changed, 40 insertions(+), 15 deletions(-)
> >
> > diff --git a/block/file-posix.c b/block/file-posix.c
> > index 07bb061fe4..6a1714d4a8 100644
> > --- a/block/file-posix.c
> > +++ b/block/file-posix.c
> > @@ -545,11 +545,18 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
> >
> > #ifdef CONFIG_LINUX_AIO
> > /* Currently Linux does AIO only for files opened with O_DIRECT */
> > - if (s->use_linux_aio && !(s->open_flags & O_DIRECT)) {
> > - error_setg(errp, "aio=native was specified, but it requires "
> > - "cache.direct=on, which was not specified.");
> > - ret = -EINVAL;
> > - goto fail;
> > + if (s->use_linux_aio) {
> > + if (!(s->open_flags & O_DIRECT)) {
> > + error_setg(errp, "aio=native was specified, but it requires "
> > + "cache.direct=on, which was not specified.");
> > + ret = -EINVAL;
> > + goto fail;
> > + }
> > + ret = aio_setup_linux_aio(bdrv_get_aio_context(bs));
> > + if (ret != 0) {
> > + error_setg(errp, "Unable to setup native AIO context.");
> > + goto fail;
> > + }
> > }
> > #else
> > if (s->use_linux_aio) {
> > diff --git a/block/linux-aio.c b/block/linux-aio.c
> > index 88b8d55ec7..4d799f85fe 100644
> > --- a/block/linux-aio.c
> > +++ b/block/linux-aio.c
> > @@ -470,28 +470,33 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
> > qemu_laio_poll_cb);
> > }
> >
> > -LinuxAioState *laio_init(void)
> > +int laio_init(LinuxAioState **linux_aio)
> > {
> > + int rc;
> > LinuxAioState *s;
> >
> > s = g_malloc0(sizeof(*s));
> > - if (event_notifier_init(&s->e, false) < 0) {
> > + rc = event_notifier_init(&s->e, false);
> > + if (rc < 0) {
>
> It would be nice if the error message could distinguish this error...
>
> > goto out_free_state;
> > }
> >
> > - if (io_setup(MAX_EVENTS, &s->ctx) != 0) {
> > + rc = io_setup(MAX_EVENTS, &s->ctx);
> > + if (rc != 0) {
>
> ... from this one. And it also makes sense to propagate the errno back with
> error_setg_errno.
>
> To do this, add an "Error **errp" parameter to the function and you
> can keep the return type (LinuxAioState *).
Thank you for this suggestion! I will send out a v4 with this and your
other feedback integrated.
-Nish
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH v3 2/2] block/file-posix: reconfigure aio on iothread start
2018-06-22 9:02 ` Kevin Wolf
@ 2018-06-22 17:12 ` Nishanth Aravamudan
0 siblings, 0 replies; 8+ messages in thread
From: Nishanth Aravamudan @ 2018-06-22 17:12 UTC (permalink / raw)
To: Kevin Wolf
Cc: Fam Zheng, Eric Blake, John Snow, Max Reitz, Stefan Hajnoczi,
Paolo Bonzini, qemu-block, qemu-devel
On 22.06.2018 [11:02:06 +0200], Kevin Wolf wrote:
> Am 22.06.2018 um 04:25 hat Fam Zheng geschrieben:
> > On Thu, 06/21 15:21, Nishanth Aravamudan wrote:
> > > When the AioContext changes, we need to associate a LinuxAioState with
> > > the new AioContext. Use the bdrv_attach_aio_context callback and call
> > > the new aio_setup_linux_aio(), which will allocate a new AioContext if
> > > needed, and return errors on failures. If it fails for any reason,
> > > fallback to threaded AIO with an error message, as the device is already
> > > in-use by the guest.
> > >
> > > Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com>
> > > ---
> > > Note this patch didn't exist in v2, but is a result of feedback to that
> > > posting.
> >
> > This should be squashed into patch 1, no?
>
> Yes, without it, patch 1 is incorrect. Specifically, at least the
> assertion in aio_get_linux_aio() won't hold true without it.
Yes, you are right! Sorry about that. I'll send a v4 today.
-Nish
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2018-06-22 17:12 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-06-21 22:21 [Qemu-devel] [PATCH v3 0/2] linux-aio: fix two NULL pointer dereferences failure paths Nishanth Aravamudan
2018-06-21 22:21 ` [Qemu-devel] [PATCH v3 1/2] linux-aio: properly bubble up errors from initialization Nishanth Aravamudan
2018-06-22 2:21 ` Fam Zheng
2018-06-22 17:12 ` Nishanth Aravamudan
2018-06-21 22:21 ` [Qemu-devel] [PATCH v3 2/2] block/file-posix: reconfigure aio on iothread start Nishanth Aravamudan
2018-06-22 2:25 ` Fam Zheng
2018-06-22 9:02 ` Kevin Wolf
2018-06-22 17:12 ` Nishanth Aravamudan
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