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[58/87] coda: check for async upcall request using local state

Message ID 20211109023433.ihghnWvdN%akpm@linux-foundation.org (mailing list archive)
State New
Headers show
Series [01/87] vfs: keep inodes with page cache off the inode shrinker LRU | expand

Commit Message

Andrew Morton Nov. 9, 2021, 2:34 a.m. UTC 
From: Jan Harkes <jaharkes@cs.cmu.edu>
Subject: coda: check for async upcall request using local state

Originally flagged by Smatch because the code implicitly assumed outSize
is not NULL for non-async upcalls because of a flag that was (not) set in
req->uc_flags.

However req->uc_flags field is in shared state and although the current
code will not allow it to be changed before the async request check the
code is more robust when it tests against the local outSize variable.

Link: https://lkml.kernel.org/r/20210908140308.18491-3-jaharkes@cs.cmu.edu
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Jing Yangyang <jing.yangyang@zte.com.cn>
Cc: Xin Tan <tanxin.ctf@gmail.com>
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/coda/upcall.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

--- a/fs/coda/upcall.c~coda-check-for-async-upcall-request-using-local-state
+++ a/fs/coda/upcall.c
@@ -744,7 +744,8 @@  static int coda_upcall(struct venus_comm
 	list_add_tail(&req->uc_chain, &vcp->vc_pending);
 	wake_up_interruptible(&vcp->vc_waitq);
 
-	if (req->uc_flags & CODA_REQ_ASYNC) {
+	/* We can return early on asynchronous requests */
+	if (outSize == NULL) {
 		mutex_unlock(&vcp->vc_mutex);
 		return 0;
 	}