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>

3 files changed, 12 insertions, 12 deletions

diff --git a/block/block-backend.c b/block/block-backend.c
index e9cc7d291e..7ba436811b 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1983,12 +1983,12 @@ void blk_activate(BlockBackend *blk, Error **errp)
     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 3b112095a4..433a25fc91 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -3757,7 +3757,7 @@ out:
     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 @@ static BlockDriver bdrv_host_cdrom = {
                         = 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 @@ static int cdrom_reopen(BlockDriverState *bs)
     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 @@ static BlockDriver bdrv_host_cdrom = {
                         = 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 d988053e4e..1093b8d4b9 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1622,7 +1622,7 @@ int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
 
     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 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
 
     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 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
 
     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 @@ int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, int64_t offset,
     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 @@ static int coroutine_fn bdrv_co_copy_range_internal(
     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 @@ static int coroutine_fn bdrv_co_copy_range_internal(
         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);