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From:   Scott Mayhew <smayhew@redhat.com>
To:     trond.myklebust@hammerspace.com, anna.schumaker@netapp.com
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH] NFS: Ensure the NFS_CAP_SECURITY_LABEL capability is set when appropriate
Date:   Wed,  2 Jun 2021 13:13:11 -0400
Message-Id: <20210602171311.1674469-1-smayhew@redhat.com>
MIME-Version: 1.0
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Precedence: bulk

Commit ce62b114bbad ("NFS: Split attribute support out from the server
capabilities") removed the logic from _nfs4_server_capabilities() that
sets the NFS_CAP_SECURITY_LABEL capability based on the presence of
FATTR4_WORD2_SECURITY_LABEL in the attr_bitmask of the server's response.
Now NFS_CAP_SECURITY_LABEL is never set, which breaks labelled NFS.

This was replaced with logic that clears the NFS_ATTR_FATTR_V4_SECURITY_LABEL
bit in the newly added fattr_valid field based on the absence of
FATTR4_WORD2_SECURITY_LABEL in the attr_bitmask of the server's response.
This essentially has no effect since there's nothing looks for that bit
in fattr_supported.

So revert that part of the commit, but adding the logic that sets
NFS_CAP_SECURITY_LABEL near where the other capabilities are set in
_nfs4_server_capabilities().

Fixes: ce62b114bbad ("NFS: Split attribute support out from the server capabilities")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
---
 fs/nfs/nfs4proc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0cd965882232..31b145043544 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3878,6 +3878,10 @@ static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *f
 			server->caps |= NFS_CAP_HARDLINKS;
 		if (res.has_symlinks != 0)
 			server->caps |= NFS_CAP_SYMLINKS;
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+		if (res.attr_bitmask[2] & FATTR4_WORD2_SECURITY_LABEL)
+			server->caps |= NFS_CAP_SECURITY_LABEL;
+#endif
 		if (!(res.attr_bitmask[0] & FATTR4_WORD0_FILEID))
 			server->fattr_valid &= ~NFS_ATTR_FATTR_FILEID;
 		if (!(res.attr_bitmask[1] & FATTR4_WORD1_MODE))
@@ -3898,10 +3902,6 @@ static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *f
 			server->fattr_valid &= ~NFS_ATTR_FATTR_CTIME;
 		if (!(res.attr_bitmask[1] & FATTR4_WORD1_TIME_MODIFY))
 			server->fattr_valid &= ~NFS_ATTR_FATTR_MTIME;
-#ifdef CONFIG_NFS_V4_SECURITY_LABEL
-		if (!(res.attr_bitmask[2] & FATTR4_WORD2_SECURITY_LABEL))
-			server->fattr_valid &= ~NFS_ATTR_FATTR_V4_SECURITY_LABEL;
-#endif
 		memcpy(server->attr_bitmask_nl, res.attr_bitmask,
 				sizeof(server->attr_bitmask));
 		server->attr_bitmask_nl[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
-- 
2.30.2