The patch titled
Subject: mm/cma_debug.c: check for debugfs_create_dir() failure
has been added to the -mm tree. Its filename is
mm-cma_debug-check-for-null-tmp-in-cma_debugfs_add_one.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-cma_debug-check-for-null-tmp-in-cma_debugfs_add_one.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-cma_debug-check-for-null-tmp-in-cma_debugfs_add_one.patch
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------------------------------------------------------
From: Yue Hu <huyue2@xxxxxxxxxx>
Subject: mm/cma_debug.c: check for debugfs_create_dir() failure
If debugfs_create_dir() fails, the following debugfs_create_file() will be
meaningless since it depends on non-NULL tmp dentry and it will only waste
CPU resource.
Link: http://lkml.kernel.org/r/20190221040130.8940-2-zbestahu@xxxxxxxxx
Signed-off-by: Yue Hu <huyue2@xxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/cma_debug.c~mm-cma_debug-check-for-null-tmp-in-cma_debugfs_add_one
+++ a/mm/cma_debug.c
@@ -169,6 +169,8 @@ static void cma_debugfs_add_one(struct c
scnprintf(name, sizeof(name), "cma-%s", cma->name);
tmp = debugfs_create_dir(name, root_dentry);
+ if (!tmp)
+ return;
debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);
debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);
_
Patches currently in -mm which might be from huyue2@xxxxxxxxxx are
mm-cma_debug-avoid-to-use-global-cma_debugfs_root.patch
mm-cma_debug-check-for-null-tmp-in-cma_debugfs_add_one.patch
