block: Convert bdrv_is_inserted() to co_wrapper
bdrv_is_inserted() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.
Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.
At the same time, add also blk_is_inserted as co_wrapper_mixed, since it
is called in both coroutine and non-coroutine contexts.
Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally c_w_mixed_bdrv_rdlock calls AIO_WAIT_WHILE and it expects to
release the AioContext lock. Once the rwlock is ultimated and placed in
every place it needs to be, we will poll using AIO_WAIT_WHILE_UNLOCKED
and remove the AioContext lock.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-5-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index ad92fdf..ab360e8 100644
--- a/block.c
+++ b/block.c
@@ -6782,7 +6782,7 @@
/**
* Return TRUE if the media is present
*/
-bool bdrv_is_inserted(BlockDriverState *bs)
+bool coroutine_fn bdrv_co_is_inserted(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
BdrvChild *child;
@@ -6791,11 +6791,11 @@
if (!drv) {
return false;
}
- if (drv->bdrv_is_inserted) {
- return drv->bdrv_is_inserted(bs);
+ if (drv->bdrv_co_is_inserted) {
+ return drv->bdrv_co_is_inserted(bs);
}
QLIST_FOREACH(child, &bs->children, next) {
- if (!bdrv_is_inserted(child->bs)) {
+ if (!bdrv_co_is_inserted(child->bs)) {
return false;
}
}
diff --git a/block/block-backend.c b/block/block-backend.c
index e9cc7d2..7ba4368 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1983,12 +1983,12 @@
bdrv_activate(bs, errp);
}
-bool blk_is_inserted(BlockBackend *blk)
+bool coroutine_fn blk_co_is_inserted(BlockBackend *blk)
{
BlockDriverState *bs = blk_bs(blk);
IO_CODE();
- return bs && bdrv_is_inserted(bs);
+ return bs && bdrv_co_is_inserted(bs);
}
bool blk_is_available(BlockBackend *blk)
diff --git a/block/file-posix.c b/block/file-posix.c
index 3b11209..433a25f 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -3757,7 +3757,7 @@
return prio;
}
-static bool cdrom_is_inserted(BlockDriverState *bs)
+static bool coroutine_fn cdrom_co_is_inserted(BlockDriverState *bs)
{
BDRVRawState *s = bs->opaque;
int ret;
@@ -3824,7 +3824,7 @@
= raw_get_allocated_file_size,
/* removable device support */
- .bdrv_is_inserted = cdrom_is_inserted,
+ .bdrv_co_is_inserted = cdrom_co_is_inserted,
.bdrv_eject = cdrom_eject,
.bdrv_lock_medium = cdrom_lock_medium,
@@ -3883,7 +3883,7 @@
return 0;
}
-static bool cdrom_is_inserted(BlockDriverState *bs)
+static bool coroutine_fn cdrom_co_is_inserted(BlockDriverState *bs)
{
return raw_getlength(bs) > 0;
}
@@ -3954,7 +3954,7 @@
= raw_get_allocated_file_size,
/* removable device support */
- .bdrv_is_inserted = cdrom_is_inserted,
+ .bdrv_co_is_inserted = cdrom_co_is_inserted,
.bdrv_eject = cdrom_eject,
.bdrv_lock_medium = cdrom_lock_medium,
};
diff --git a/block/io.c b/block/io.c
index d988053..1093b8d 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1622,7 +1622,7 @@
trace_bdrv_co_preadv_part(bs, offset, bytes, flags);
- if (!bdrv_is_inserted(bs)) {
+ if (!bdrv_co_is_inserted(bs)) {
return -ENOMEDIUM;
}
@@ -2067,7 +2067,7 @@
trace_bdrv_co_pwritev_part(child->bs, offset, bytes, flags);
- if (!bdrv_is_inserted(bs)) {
+ if (!bdrv_co_is_inserted(bs)) {
return -ENOMEDIUM;
}
@@ -2835,7 +2835,7 @@
bdrv_inc_in_flight(bs);
- if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs) ||
+ if (!bdrv_co_is_inserted(bs) || bdrv_is_read_only(bs) ||
bdrv_is_sg(bs)) {
goto early_exit;
}
@@ -2959,7 +2959,7 @@
BlockDriverState *bs = child->bs;
IO_CODE();
- if (!bs || !bs->drv || !bdrv_is_inserted(bs)) {
+ if (!bs || !bs->drv || !bdrv_co_is_inserted(bs)) {
return -ENOMEDIUM;
}
@@ -3241,7 +3241,7 @@
assert(!(read_flags & BDRV_REQ_NO_WAIT));
assert(!(write_flags & BDRV_REQ_NO_WAIT));
- if (!dst || !dst->bs || !bdrv_is_inserted(dst->bs)) {
+ if (!dst || !dst->bs || !bdrv_co_is_inserted(dst->bs)) {
return -ENOMEDIUM;
}
ret = bdrv_check_request32(dst_offset, bytes, NULL, 0);
@@ -3252,7 +3252,7 @@
return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, write_flags);
}
- if (!src || !src->bs || !bdrv_is_inserted(src->bs)) {
+ if (!src || !src->bs || !bdrv_co_is_inserted(src->bs)) {
return -ENOMEDIUM;
}
ret = bdrv_check_request32(src_offset, bytes, NULL, 0);
diff --git a/blockdev.c b/blockdev.c
index fe9d8d8..d7b5c18 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1024,6 +1024,7 @@
static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp)
{
BlockDriverState *bs;
+ AioContext *aio_context;
bs = bdrv_lookup_bs(name, name, errp);
if (bs == NULL) {
@@ -1035,11 +1036,16 @@
return NULL;
}
+ aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(aio_context);
+
if (!bdrv_is_inserted(bs)) {
error_setg(errp, "Device has no medium");
- return NULL;
+ bs = NULL;
}
+ aio_context_release(aio_context);
+
return bs;
}
diff --git a/include/block/block-io.h b/include/block/block-io.h
index d7fd272..f27d935 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -136,7 +136,10 @@
bool bdrv_is_writable(BlockDriverState *bs);
bool bdrv_is_sg(BlockDriverState *bs);
int bdrv_get_flags(BlockDriverState *bs);
-bool bdrv_is_inserted(BlockDriverState *bs);
+
+bool coroutine_fn bdrv_co_is_inserted(BlockDriverState *bs);
+bool co_wrapper bdrv_is_inserted(BlockDriverState *bs);
+
void bdrv_lock_medium(BlockDriverState *bs, bool locked);
void bdrv_eject(BlockDriverState *bs, bool eject_flag);
const char *bdrv_get_format_name(BlockDriverState *bs);
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index b71fa04..9ec68f5 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -704,7 +704,7 @@
BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
/* removable device specific */
- bool (*bdrv_is_inserted)(BlockDriverState *bs);
+ bool coroutine_fn (*bdrv_co_is_inserted)(BlockDriverState *bs);
void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
diff --git a/include/sysemu/block-backend-io.h b/include/sysemu/block-backend-io.h
index 0d432cc..7cc96a5 100644
--- a/include/sysemu/block-backend-io.h
+++ b/include/sysemu/block-backend-io.h
@@ -54,7 +54,10 @@
void blk_inc_in_flight(BlockBackend *blk);
void blk_dec_in_flight(BlockBackend *blk);
-bool blk_is_inserted(BlockBackend *blk);
+
+bool coroutine_fn blk_co_is_inserted(BlockBackend *blk);
+bool co_wrapper_mixed blk_is_inserted(BlockBackend *blk);
+
bool blk_is_available(BlockBackend *blk);
void blk_lock_medium(BlockBackend *blk, bool locked);
void blk_eject(BlockBackend *blk, bool eject_flag);
