linux-kernel - [PATCH 15/15] afs: Fix double inc of vnode->cb

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Message-ID: <155793764807.31671.15353972412997485464.stgit@warthog.procyon.org.uk>
Date:   Wed, 15 May 2019 17:27:28 +0100
From:   David Howells <dhowells@...hat.com>
To:     linux-afs@...ts.infradead.org
Cc:     dhowells@...hat.com, linux-kernel@...r.kernel.org
Subject: [PATCH 15/15] afs: Fix double inc of vnode->cb_break

When __afs_break_callback() clears the CB_PROMISED flag, it increments
vnode->cb_break to trigger a future refetch of the status and callback -
however it also calls afs_clear_permits(), which also increments
vnode->cb_break.

Fix this by removing the increment from afs_clear_permits().

Whilst we're at it, fix the conditional call to afs_put_permits() as the
function checks to see if the argument is NULL, so the check is redundant.

Fixes: be080a6f43c4 ("afs: Overhaul permit caching");
Signed-off-by: David Howells <dhowells@...hat.com>
---

 fs/afs/security.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/afs/security.c b/fs/afs/security.c
index 5f58a9a17e69..db5529e47eb8 100644
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -87,11 +87,9 @@ void afs_clear_permits(struct afs_vnode *vnode)
 	permits = rcu_dereference_protected(vnode->permit_cache,
 					    lockdep_is_held(&vnode->lock));
 	RCU_INIT_POINTER(vnode->permit_cache, NULL);
-	vnode->cb_break++;
 	spin_unlock(&vnode->lock);

-	if (permits)
-		afs_put_permits(permits);
+	afs_put_permits(permits);
 }

 /*