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authorKevin Wolf <kwolf@redhat.com>2023-05-10 22:35:54 +0200
committerKevin Wolf <kwolf@redhat.com>2023-05-19 19:12:12 +0200
commit4db7ba3b87447fd06cd7e23dab69fdae6011496d (patch)
tree573bd54b127d2127d927fe7534d4296dee4e4a1c /block/qcow.c
parent41f8b633393021923fd555d8d94bded2f8f6f05d (diff)
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block: Call .bdrv_co_create(_opts) unlocked
These are functions that modify the graph, so they must be able to take a writer lock. This is impossible if they already hold the reader lock. If they need a reader lock for some of their operations, they should take it internally. Many of them go through blk_*(), which will always take the lock itself. Direct calls of bdrv_*() need to take the reader lock. Note that while locking for bdrv_co_*() calls is checked by TSA, this is not the case for the mixed_coroutine_fns bdrv_*(). Holding the lock is still required when they are called from coroutine context like here! This effectively reverts 4ec8df0183, but adds some internal locking instead. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230510203601.418015-2-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/qcow.c')
-rw-r--r--block/qcow.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/block/qcow.c b/block/qcow.c
index a0c701f..3644bbf 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -800,8 +800,8 @@ static void qcow_close(BlockDriverState *bs)
error_free(s->migration_blocker);
}
-static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts,
- Error **errp)
+static int coroutine_fn GRAPH_UNLOCKED
+qcow_co_create(BlockdevCreateOptions *opts, Error **errp)
{
BlockdevCreateOptionsQcow *qcow_opts;
int header_size, backing_filename_len, l1_size, shift, i;
@@ -921,7 +921,7 @@ exit:
return ret;
}
-static int coroutine_fn GRAPH_RDLOCK
+static int coroutine_fn GRAPH_UNLOCKED
qcow_co_create_opts(BlockDriver *drv, const char *filename,
QemuOpts *opts, Error **errp)
{