[Qemu-devel] [PATCH 13/22] block/raw-posix: implement .bdrv_detach/attach_aio_context()

[Stefan Hajnoczi <stefanha@redhat.com>]

Drop the assumption that we're using the main AioContext for Linux AIO.
Convert the Linux AIO event notifier to use aio_set_event_notifier().

The .bdrv_detach/attach_aio_context() interfaces also need to be
implemented to move the event notifier handler from the old to the new
AioContext.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/linux-aio.c | 16 ++++++++++++++--
 block/raw-aio.h   |  2 ++
 block/raw-posix.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/block/linux-aio.c b/block/linux-aio.c
index 53434e2..7ff3897 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -177,6 +177,20 @@ out_free_aiocb:
     return NULL;
 }
 
+void laio_detach_aio_context(void *s_, AioContext *old_context)
+{
+    struct qemu_laio_state *s = s_;
+
+    aio_set_event_notifier(old_context, &s->e, NULL);
+}
+
+void laio_attach_aio_context(void *s_, AioContext *new_context)
+{
+    struct qemu_laio_state *s = s_;
+
+    aio_set_event_notifier(new_context, &s->e, qemu_laio_completion_cb);
+}
+
 void *laio_init(void)
 {
     struct qemu_laio_state *s;
@@ -190,8 +204,6 @@ void *laio_init(void)
         goto out_close_efd;
     }
 
-    qemu_aio_set_event_notifier(&s->e, qemu_laio_completion_cb);
-
     return s;
 
 out_close_efd:
diff --git a/block/raw-aio.h b/block/raw-aio.h
index 7ad0a8a..9a761ee 100644
--- a/block/raw-aio.h
+++ b/block/raw-aio.h
@@ -37,6 +37,8 @@ void *laio_init(void);
 BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void *aio_ctx, int fd,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque, int type);
+void laio_detach_aio_context(void *s, AioContext *old_context);
+void laio_attach_aio_context(void *s, AioContext *new_context);
 #endif
 
 #ifdef _WIN32
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 1688e16..9fef157 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -304,6 +304,29 @@ static void raw_parse_flags(int bdrv_flags, int *open_flags)
     }
 }
 
+static void raw_detach_aio_context(BlockDriverState *bs)
+{
+#ifdef CONFIG_LINUX_AIO
+    BDRVRawState *s = bs->opaque;
+
+    if (s->use_aio) {
+        laio_detach_aio_context(s->aio_ctx, bdrv_get_aio_context(bs));
+    }
+#endif
+}
+
+static void raw_attach_aio_context(BlockDriverState *bs,
+                                   AioContext *new_context)
+{
+#ifdef CONFIG_LINUX_AIO
+    BDRVRawState *s = bs->opaque;
+
+    if (s->use_aio) {
+        laio_attach_aio_context(s->aio_ctx, new_context);
+    }
+#endif
+}
+
 #ifdef CONFIG_LINUX_AIO
 static int raw_set_aio(void **aio_ctx, int *use_aio, int bdrv_flags)
 {
@@ -444,6 +467,8 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
     }
 #endif
 
+    raw_attach_aio_context(bs, bdrv_get_aio_context(bs));
+
     ret = 0;
 fail:
     qemu_opts_del(opts);
@@ -1053,6 +1078,9 @@ static BlockDriverAIOCB *raw_aio_flush(BlockDriverState *bs,
 static void raw_close(BlockDriverState *bs)
 {
     BDRVRawState *s = bs->opaque;
+
+    raw_detach_aio_context(bs);
+
     if (s->fd >= 0) {
         qemu_close(s->fd);
         s->fd = -1;
@@ -1448,6 +1476,9 @@ static BlockDriver bdrv_file = {
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 
+    .bdrv_detach_aio_context = raw_detach_aio_context,
+    .bdrv_attach_aio_context = raw_attach_aio_context,
+
     .create_options = raw_create_options,
 };
 
@@ -1848,6 +1879,9 @@ static BlockDriver bdrv_host_device = {
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 
+    .bdrv_detach_aio_context = raw_detach_aio_context,
+    .bdrv_attach_aio_context = raw_attach_aio_context,
+
     /* generic scsi device */
 #ifdef __linux__
     .bdrv_ioctl         = hdev_ioctl,
@@ -1990,6 +2024,9 @@ static BlockDriver bdrv_host_floppy = {
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 
+    .bdrv_detach_aio_context = raw_detach_aio_context,
+    .bdrv_attach_aio_context = raw_attach_aio_context,
+
     /* removable device support */
     .bdrv_is_inserted   = floppy_is_inserted,
     .bdrv_media_changed = floppy_media_changed,
@@ -2115,6 +2152,9 @@ static BlockDriver bdrv_host_cdrom = {
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 
+    .bdrv_detach_aio_context = raw_detach_aio_context,
+    .bdrv_attach_aio_context = raw_attach_aio_context,
+
     /* removable device support */
     .bdrv_is_inserted   = cdrom_is_inserted,
     .bdrv_eject         = cdrom_eject,
@@ -2246,6 +2286,9 @@ static BlockDriver bdrv_host_cdrom = {
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 
+    .bdrv_detach_aio_context = raw_detach_aio_context,
+    .bdrv_attach_aio_context = raw_attach_aio_context,
+
     /* removable device support */
     .bdrv_is_inserted   = cdrom_is_inserted,
     .bdrv_eject         = cdrom_eject,
-- 
1.9.0