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From: Josef Bacik <josef@toxicpanda.com>
To: trond.myklebust@hammerspace.com,
	anna@kernel.org,
	linux-nfs@vger.kernel.org
Subject: [PATCH 1/2] nfs: properly protect nfs_direct_req fields
Date: Fri,  1 Mar 2024 11:49:56 -0500
Message-ID: <ca2f5e31d321b19fdb033f10ce6aec79c337a648.1709311699.git.josef@toxicpanda.com>
In-Reply-To: <cover.1709311699.git.josef@toxicpanda.com>
References: <cover.1709311699.git.josef@toxicpanda.com>
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We protect accesses to the nfs_direct_req fields with the dreq->lock
ever where except nfs_direct_commit_complete.  This isn't a huge deal,
but it does lead to confusion, and we could potentially end up setting
NFS_ODIRECT_RESCHED_WRITES in one thread where we've had an error in
another.  Clean this up to properly protect ->error and ->flags in the
commit completion path.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/nfs/direct.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index c03926a1cc73..befcc167e25f 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -606,6 +606,7 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data)
 
 	trace_nfs_direct_commit_complete(dreq);
 
+	spin_lock(&dreq->lock);
 	if (status < 0) {
 		/* Errors in commit are fatal */
 		dreq->error = status;
@@ -613,6 +614,7 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data)
 	} else {
 		status = dreq->error;
 	}
+	spin_unlock(&dreq->lock);
 
 	nfs_init_cinfo_from_dreq(&cinfo, dreq);
 
@@ -625,7 +627,10 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data)
 			spin_unlock(&dreq->lock);
 			nfs_release_request(req);
 		} else if (!nfs_write_match_verf(verf, req)) {
-			dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+			spin_lock(&dreq->lock);
+			if (dreq->flags == 0)
+				dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+			spin_unlock(&dreq->lock);
 			/*
 			 * Despite the reboot, the write was successful,
 			 * so reset wb_nio.
-- 
2.43.0