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[PATCH 13/24] block: Mark bdrv_set_backing_hd_drained() GRAPH_WRLOCK
From: |
Kevin Wolf |
Subject: |
[PATCH 13/24] block: Mark bdrv_set_backing_hd_drained() GRAPH_WRLOCK |
Date: |
Fri, 27 Oct 2023 17:53:22 +0200 |
Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_set_backing_hd_drained(). Basically everthing
in the function needs the lock and its callers may already want to hold
the graph lock and so wouldn't be able to call functions that take it
internally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
include/block/block-global-state.h | 7 ++++---
block.c | 4 ++--
block/stream.c | 2 ++
3 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/include/block/block-global-state.h
b/include/block/block-global-state.h
index 9a33bd7ef9..a1fd70ec97 100644
--- a/include/block/block-global-state.h
+++ b/include/block/block-global-state.h
@@ -101,9 +101,10 @@ bdrv_co_open_blockdev_ref(BlockdevRef *ref, Error **errp);
int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
Error **errp);
-int bdrv_set_backing_hd_drained(BlockDriverState *bs,
- BlockDriverState *backing_hd,
- Error **errp);
+int GRAPH_WRLOCK
+bdrv_set_backing_hd_drained(BlockDriverState *bs, BlockDriverState *backing_hd,
+ Error **errp);
+
int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
const char *bdref_key, Error **errp);
diff --git a/block.c b/block.c
index 499b147315..d79a6f41f9 100644
--- a/block.c
+++ b/block.c
@@ -3557,7 +3557,6 @@ int bdrv_set_backing_hd_drained(BlockDriverState *bs,
if (bs->backing) {
assert(bs->backing->bs->quiesce_counter > 0);
}
- bdrv_graph_wrlock(backing_hd);
ret = bdrv_set_backing_noperm(bs, backing_hd, tran, errp);
if (ret < 0) {
@@ -3567,7 +3566,6 @@ int bdrv_set_backing_hd_drained(BlockDriverState *bs,
ret = bdrv_refresh_perms(bs, tran, errp);
out:
tran_finalize(tran, ret);
- bdrv_graph_wrunlock();
return ret;
}
@@ -3580,7 +3578,9 @@ int bdrv_set_backing_hd(BlockDriverState *bs,
BlockDriverState *backing_hd,
bdrv_ref(drain_bs);
bdrv_drained_begin(drain_bs);
+ bdrv_graph_wrlock(backing_hd);
ret = bdrv_set_backing_hd_drained(bs, backing_hd, errp);
+ bdrv_graph_wrunlock();
bdrv_drained_end(drain_bs);
bdrv_unref(drain_bs);
diff --git a/block/stream.c b/block/stream.c
index 3f5d773535..0b92410c00 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -99,7 +99,9 @@ static int stream_prepare(Job *job)
}
}
+ bdrv_graph_wrlock(base);
bdrv_set_backing_hd_drained(unfiltered_bs, base, &local_err);
+ bdrv_graph_wrunlock();
/*
* This call will do I/O, so the graph can change again from here on.
--
2.41.0
- [PATCH 00/24] block: Graph locking part 6 (bs->file/backing), Kevin Wolf, 2023/10/27
- [PATCH 01/24] block: Mark bdrv_probe_blocksizes() and callers GRAPH_RDLOCK, Kevin Wolf, 2023/10/27
- [PATCH 02/24] block: Mark bdrv_has_zero_init() and callers GRAPH_RDLOCK, Kevin Wolf, 2023/10/27
- [PATCH 08/24] block: Mark bdrv_skip_filters() and callers GRAPH_RDLOCK, Kevin Wolf, 2023/10/27
- [PATCH 13/24] block: Mark bdrv_set_backing_hd_drained() GRAPH_WRLOCK,
Kevin Wolf <=
- [PATCH 11/24] block: Mark bdrv_filter_child() and callers GRAPH_RDLOCK, Kevin Wolf, 2023/10/27
- [PATCH 03/24] block: Mark bdrv_filter_bs() and callers GRAPH_RDLOCK, Kevin Wolf, 2023/10/27
- [PATCH 05/24] block: Mark block_job_add_bdrv() GRAPH_WRLOCK, Kevin Wolf, 2023/10/27
- [PATCH 15/24] block: Mark bdrv_replace_node_common() GRAPH_WRLOCK, Kevin Wolf, 2023/10/27