Re: [PATCH v8 1/3] lib: zstd: Add kernel-specific API

[Oleksandr Natalenko]

Hello.

On Sat, Mar 27, 2021 at 05:48:01PM +0800, kernel test robot wrote:
> >> ERROR: modpost: "ZSTD_maxCLevel" [fs/f2fs/f2fs.ko] undefined!

Since f2fs can be built as a module, the following correction seems to
be needed:

```
diff --git a/lib/zstd/compress/zstd_compress.c b/lib/zstd/compress/zstd_compress.c
index 9c998052a0e5..584c92c51169 100644
--- a/lib/zstd/compress/zstd_compress.c
+++ b/lib/zstd/compress/zstd_compress.c
@@ -4860,6 +4860,7 @@ size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
 
 #define ZSTD_MAX_CLEVEL     22
 int ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
+EXPORT_SYMBOL(ZSTD_maxCLevel);
 int ZSTD_minCLevel(void) { return (int)-ZSTD_TARGETLENGTH_MAX; }
 
 static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEVEL+1] = {
```

Not sure if the same should be done for `ZSTD_minCLevel()` since I don't
see it being used anywhere else.

-- 
  Oleksandr Natalenko (post-factum)