[Cluster-devel] [PATCH v5.14-rc1 02/12] fs: dlm: use READ_ONCE for config var

Alexander Aring aahringo at redhat.com
Fri Jul 16 20:22:35 UTC 2021


This patch will use READ_ONCE to signal the compiler to read this
variable only one time. If we don't do that it could be that the
compiler read this value more than one time, because some optimizations,
from the configure data which might can be changed during this time.

Signed-off-by: Alexander Aring <aahringo at redhat.com>
---
 fs/dlm/lockspace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index d71aba8c3e64..23c2d7308050 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -498,7 +498,7 @@ static int new_lockspace(const char *name, const char *cluster,
 	ls->ls_exflags = (flags & ~(DLM_LSFL_TIMEWARN | DLM_LSFL_FS |
 				    DLM_LSFL_NEWEXCL));
 
-	size = dlm_config.ci_rsbtbl_size;
+	size = READ_ONCE(dlm_config.ci_rsbtbl_size);
 	ls->ls_rsbtbl_size = size;
 
 	ls->ls_rsbtbl = vmalloc(array_size(size, sizeof(struct dlm_rsbtable)));
-- 
2.27.0




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