Patch "NFSv4: Fix a regression in nfs_set_open_stateid_locked()" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    NFSv4: Fix a regression in nfs_set_open_stateid_locked()

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsv4-fix-a-regression-in-nfs_set_open_stateid_locke.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 1e8c085c24a0b088fd66dcd185b2a790f914396e
Author: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Date:   Tue Oct 26 21:56:40 2021 -0400

    NFSv4: Fix a regression in nfs_set_open_stateid_locked()
    
    [ Upstream commit 01d29f87fcfef38d51ce2b473981a5c1e861ac0a ]
    
    If we already hold open state on the client, yet the server gives us a
    completely different stateid to the one we already hold, then we
    currently treat it as if it were an out-of-sequence update, and wait for
    5 seconds for other updates to come in.
    This commit fixes the behaviour so that we immediately start processing
    of the new stateid, and then leave it to the call to
    nfs4_test_and_free_stateid() to decide what to do with the old stateid.
    
    Fixes: b4868b44c562 ("NFSv4: Wait for stateid updates after CLOSE/OPEN_DOWNGRADE")
    Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 5365000e83bd6..3106bd28b1132 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1590,15 +1590,16 @@ static bool nfs_stateid_is_sequential(struct nfs4_state *state,
 {
 	if (test_bit(NFS_OPEN_STATE, &state->flags)) {
 		/* The common case - we're updating to a new sequence number */
-		if (nfs4_stateid_match_other(stateid, &state->open_stateid) &&
-			nfs4_stateid_is_next(&state->open_stateid, stateid)) {
-			return true;
+		if (nfs4_stateid_match_other(stateid, &state->open_stateid)) {
+			if (nfs4_stateid_is_next(&state->open_stateid, stateid))
+				return true;
+			return false;
 		}
-	} else {
-		/* This is the first OPEN in this generation */
-		if (stateid->seqid == cpu_to_be32(1))
-			return true;
+		/* The server returned a new stateid */
 	}
+	/* This is the first OPEN in this generation */
+	if (stateid->seqid == cpu_to_be32(1))
+		return true;
 	return false;
 }