linux-kernel - [PATCH] netfs: Ensure ret is always initialized in netfs_begin

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Date:   Thu,  3 Mar 2022 09:38:26 -0700
From:   Nathan Chancellor <nathan@...nel.org>
To:     David Howells <dhowells@...hat.com>
Cc:     llvm@...ts.linux.dev, linux-kernel@...r.kernel.org,
        Tom Rix <trix@...hat.com>,
        Nathan Chancellor <nathan@...nel.org>,
        kernel test robot <lkp@...el.com>
Subject: [PATCH] netfs: Ensure ret is always initialized in netfs_begin_read()

Clang warns:

  fs/netfs/io.c:630:6: error: variable 'ret' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
          if (sync) {
              ^~~~
  fs/netfs/io.c:655:9: note: uninitialized use occurs here
          return ret;
                 ^~~

There is only one instance of netfs_begin_read() where sync is false and
its return value is not checked so just return 0 in this case, as there
is no return code from another function call to propagate.

Fixes: 33e1e5d53058 ("netfs: Add a function to consolidate beginning a read")
Link: https://github.com/ClangBuiltLinux/linux/issues/1607
Reported-by: kernel test robot <lkp@...el.com>
Signed-off-by: Nathan Chancellor <nathan@...nel.org>
---
 fs/netfs/io.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index 3db9356eb7c2..4a3b7989cd1c 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -651,6 +651,7 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
 		/* If we decrement nr_outstanding to 0, the ref belongs to us. */
 		if (atomic_dec_and_test(&rreq->nr_outstanding))
 			netfs_rreq_assess(rreq, false);
+		ret = 0;
 	}
 	return ret;
 }

base-commit: 2522c1b16116325f69670076d0c82024fbcc4e8d
-- 
2.35.1