bdrv_set_aio_context can take care of children recursively, so it is
okay to pass down the perm.
Signed-off-by: Fam Zheng <f...@redhat.com>
---
block.c | 18 ++++++++++--------
block/vvfat.c | 2 +-
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/block.c b/block.c
index ae9327b..0190087 100644
--- a/block.c
+++ b/block.c
@@ -1670,7 +1670,8 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm,
uint64_t shared,
#define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
| BLK_PERM_WRITE \
| BLK_PERM_WRITE_UNCHANGED \
- | BLK_PERM_RESIZE)
+ | BLK_PERM_RESIZE \
+ | BLK_PERM_AIO_CONTEXT_CHANGE)
#define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
@@ -1713,21 +1714,22 @@ void bdrv_format_default_perms(BlockDriverState *bs,
BdrvChild *c,
perm |= BLK_PERM_CONSISTENT_READ;
shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
} else {
- /* We want consistent read from backing files if the parent needs it.
+ /* We want consistent read and aio context change from backing files if
+ * the parent needs it.
* No other operations are performed on backing files. */
- perm &= BLK_PERM_CONSISTENT_READ;
+ perm &= BLK_PERM_CONSISTENT_READ | BLK_PERM_AIO_CONTEXT_CHANGE;
- /* If the parent can deal with changing data, we're okay with a
+ /* If the parent can deal with changing aio context, we're okay too;
+ * If the parent can deal with changing data, we're okay with a
* writable and resizable backing file. */
/* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
+ shared &= BLK_PERM_AIO_CONTEXT_CHANGE | BLK_PERM_WRITE;
if (shared & BLK_PERM_WRITE) {
- shared = BLK_PERM_WRITE | BLK_PERM_RESIZE;
- } else {
- shared = 0;
+ shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
}
shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
- BLK_PERM_WRITE_UNCHANGED;
+ BLK_PERM_WRITE_UNCHANGED | BLK_PERM_AIO_CONTEXT_CHANGE;
}
*nperm = perm;
diff --git a/block/vvfat.c b/block/vvfat.c
index af5153d..70ce452 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -3080,7 +3080,7 @@ static void vvfat_child_perm(BlockDriverState *bs,
BdrvChild *c,
if (c == s->qcow) {
/* This is a private node, nobody should try to attach to it */
*nperm = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE;
- *nshared = BLK_PERM_WRITE_UNCHANGED;
+ *nshared = BLK_PERM_WRITE_UNCHANGED | BLK_PERM_AIO_CONTEXT_CHANGE;
} else {
/* The backing file is there so 'commit' can use it. vvfat doesn't
* access it in any way. */
--
2.9.3
