From: NeilBrown <neilb@suse.de>
Date: Mon, 27 Sep 2021 11:19:36 +1000
Subject: [PATCH] NFS: change nfs_access_get_cached to only report the mask
Patch-mainline: Submitted, 25sep2021 linux-nfs
References: bsc#1190746

Currently the nfs_access_get_cached family of functions report a
'struct nfs_access_entry' as the result, with both .mask and .cred set.
However the .cred is never used.  This is probably good and there is no
guarantee that it won't be freed before use.

Change to only report the 'mask' - as this is all that is used or needed.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/dir.c |   14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2321,7 +2321,7 @@ static struct nfs_access_entry *nfs_acce
 	return NULL;
 }
 
-static int nfs_access_get_cached(struct inode *inode, const struct cred *cred, struct nfs_access_entry *res, bool may_block)
+static int nfs_access_get_cached(struct inode *inode, const struct cred *cred, u32 *mask, bool may_block)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	struct nfs_access_entry *cache;
@@ -2351,8 +2351,7 @@ static int nfs_access_get_cached(struct
 		spin_lock(&inode->i_lock);
 		retry = false;
 	}
-	res->cred = cache->cred;
-	res->mask = cache->mask;
+	*mask = cache->mask;
 	list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
 	err = 0;
 out:
@@ -2364,7 +2363,7 @@ out_zap:
 	return -ENOENT;
 }
 
-static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cred, struct nfs_access_entry *res)
+static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cred, u32 *mask)
 {
 	/* Only check the most recently returned cache entry,
 	 * but do it without locking.
@@ -2386,8 +2385,7 @@ static int nfs_access_get_cached_rcu(str
 		goto out;
 	if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
 		goto out;
-	res->cred = cache->cred;
-	res->mask = cache->mask;
+	*mask = cache->mask;
 	err = 0;
 out:
 	rcu_read_unlock();
@@ -2508,9 +2506,9 @@ static int nfs_do_access(struct inode *i
 
 	trace_nfs_access_enter(inode);
 
-	status = nfs_access_get_cached_rcu(inode, cred, &cache);
+	status = nfs_access_get_cached_rcu(inode, cred, &cache.mask);
 	if (status != 0)
-		status = nfs_access_get_cached(inode, cred, &cache, may_block);
+		status = nfs_access_get_cached(inode, cred, &cache.mask, may_block);
 	if (status == 0)
 		goto out_cached;