commit 1f051dcbdf2e4b6f518db731c84e304b2b9d15ce
author Kevin Wolf <kwolf@redhat.com> Fri Oct 27 17:53:33 2023 +0200
committer Kevin Wolf <kwolf@redhat.com> Wed Nov 08 17:56:18 2023 +0100
tree c96479cc14a8cc90443bc4f7fe46afbfa76a4006
parent a4b740db5ee3db0d5b76a6ea9895875763453187

block: Protect bs->file with graph_lock

Almost all functions that access bs->file already take the graph
lock now. Add locking to the remaining users and finally annotate the
struct field itself as protected by the graph lock.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-25-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/preallocate.c

diff --git a/block/preallocate.c b/block/preallocate.c
index f302d17..d215bc5 100644
--- a/block/preallocate.c
+++ b/block/preallocate.c
@@ -173,7 +173,8 @@
     return 0;
 }
 
-static int preallocate_truncate_to_real_size(BlockDriverState *bs, Error **errp)
+static int GRAPH_RDLOCK
+preallocate_truncate_to_real_size(BlockDriverState *bs, Error **errp)
 {
     BDRVPreallocateState *s = bs->opaque;
     int ret;
@@ -204,6 +205,9 @@
 {
     BDRVPreallocateState *s = bs->opaque;
 
+    GLOBAL_STATE_CODE();
+    GRAPH_RDLOCK_GUARD_MAINLOOP();
+
     qemu_bh_cancel(s->drop_resize_bh);
     qemu_bh_delete(s->drop_resize_bh);
 
@@ -227,6 +231,9 @@
     PreallocateOpts *opts = g_new0(PreallocateOpts, 1);
     int ret;
 
+    GLOBAL_STATE_CODE();
+    GRAPH_RDLOCK_GUARD_MAINLOOP();
+
     if (!preallocate_absorb_opts(opts, reopen_state->options,
                                  reopen_state->bs->file->bs, errp)) {
         g_free(opts);
@@ -287,7 +294,7 @@
     return (perm & BLK_PERM_WRITE) && (perm & BLK_PERM_RESIZE);
 }
 
-static bool has_prealloc_perms(BlockDriverState *bs)
+static bool GRAPH_RDLOCK has_prealloc_perms(BlockDriverState *bs)
 {
     BDRVPreallocateState *s = bs->opaque;
 
@@ -503,7 +510,8 @@
     return ret;
 }
 
-static int preallocate_drop_resize(BlockDriverState *bs, Error **errp)
+static int GRAPH_RDLOCK
+preallocate_drop_resize(BlockDriverState *bs, Error **errp)
 {
     BDRVPreallocateState *s = bs->opaque;
     int ret;
@@ -529,15 +537,16 @@
      */
     s->data_end = s->file_end = s->zero_start = -EINVAL;
 
-    bdrv_graph_rdlock_main_loop();
     bdrv_child_refresh_perms(bs, bs->file, NULL);
-    bdrv_graph_rdunlock_main_loop();
 
     return 0;
 }
 
 static void preallocate_drop_resize_bh(void *opaque)
 {
+    GLOBAL_STATE_CODE();
+    GRAPH_RDLOCK_GUARD_MAINLOOP();
+
     /*
      * In case of errors, we'll simply keep the exclusive lock on the image
      * indefinitely.