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 <naravamu...@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
