From: NeilBrown <neilb@suse.com>
To: "J. Bruce Fields" <bfields@fieldses.org>,
Chuck Lever <chuck.lever@oracle.com>,
Jeff Layton <jlayton@kernel.org>,
Trond Myklebust <trond.myklebust@hammerspace.com>,
Anna Schumaker <anna.schumaker@netapp.com>
Cc: Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH 04/23] cred: allow get_cred() and put_cred() to be given NULL.
Date: Mon, 03 Dec 2018 11:30:30 +1100 [thread overview]
Message-ID: <154379703020.28598.1657780881720707861.stgit@noble> (raw)
In-Reply-To: <154379689752.28598.6750646657534626618.stgit@noble>
It is common practice for helpers like this to silently,
accept a NULL pointer.
get_rpccred() and put_rpccred() used by NFS act this way
and using the same interface will ease the conversion
for NFS, and simplify the resulting code.
Signed-off-by: NeilBrown <neilb@suse.com>
---
include/linux/cred.h | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/include/linux/cred.h b/include/linux/cred.h
index 48979fcb95cf..4907c9df86b3 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -237,7 +237,7 @@ static inline struct cred *get_new_cred(struct cred *cred)
* @cred: The credentials to reference
*
* Get a reference on the specified set of credentials. The caller must
- * release the reference.
+ * release the reference. If %NULL is passed, it is returned with no action.
*
* This is used to deal with a committed set of credentials. Although the
* pointer is const, this will temporarily discard the const and increment the
@@ -248,6 +248,8 @@ static inline struct cred *get_new_cred(struct cred *cred)
static inline const struct cred *get_cred(const struct cred *cred)
{
struct cred *nonconst_cred = (struct cred *) cred;
+ if (!cred)
+ return cred;
validate_creds(cred);
return get_new_cred(nonconst_cred);
}
@@ -268,7 +270,7 @@ static inline const struct cred *get_cred_rcu(const struct cred *cred)
* @cred: The credentials to release
*
* Release a reference to a set of credentials, deleting them when the last ref
- * is released.
+ * is released. If %NULL is passed, nothing is done.
*
* This takes a const pointer to a set of credentials because the credentials
* on task_struct are attached by const pointers to prevent accidental
@@ -278,9 +280,11 @@ static inline void put_cred(const struct cred *_cred)
{
struct cred *cred = (struct cred *) _cred;
- validate_creds(cred);
- if (atomic_dec_and_test(&(cred)->usage))
- __put_cred(cred);
+ if (cred) {
+ validate_creds(cred);
+ if (atomic_dec_and_test(&(cred)->usage))
+ __put_cred(cred);
+ }
}
/**
next prev parent reply other threads:[~2018-12-03 0:32 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 0:30 [PATCH 00/23 - V5] NFS: Remove generic RPC credentials NeilBrown
2018-12-03 0:30 ` [PATCH 05/23] SUNRPC: add 'struct cred *' to auth_cred and rpc_cred NeilBrown
2018-12-03 0:30 ` [PATCH 15/23] NFS: move credential expiry tracking out of SUNRPC into NFS NeilBrown
2018-12-03 0:30 ` [PATCH 14/23] SUNRPC: add side channel to use non-generic cred for rpc call NeilBrown
2018-12-03 0:30 ` [PATCH 03/23] cred: export get_task_cred() NeilBrown
2018-12-03 0:30 ` [PATCH 16/23] SUNRPC: remove RPCAUTH_AUTH_NO_CRKEY_TIMEOUT NeilBrown
2018-12-03 0:30 ` [PATCH 18/23] NFS: struct nfs_open_dir_context: convert rpc_cred pointer to cred NeilBrown
2018-12-03 0:30 ` [PATCH 11/23] SUNRPC: discard RPC_DO_ROOTOVERRIDE() NeilBrown
2018-12-03 0:30 ` [PATCH 08/23] SUNRPC: remove machine_cred field from struct auth_cred NeilBrown
2018-12-03 0:30 ` [PATCH 12/23] NFS/SUNRPC: don't lookup machine credential until rpcauth_bindcred() NeilBrown
2018-12-03 0:30 ` [PATCH 09/23] NFSv4: add cl_root_cred for use when machine cred is not available NeilBrown
2018-12-03 0:30 ` [PATCH 06/23] SUNRPC: remove groupinfo from struct auth_cred NeilBrown
2018-12-03 0:30 ` NeilBrown [this message]
2018-12-03 0:30 ` [PATCH 13/23] SUNRPC: introduce RPC_TASK_NULLCREDS to request auth_none NeilBrown
2018-12-03 0:30 ` [PATCH 07/23] SUNRPC: remove uid and gid from struct auth_cred NeilBrown
2018-12-03 0:30 ` [PATCH 02/23] cred: add get_cred_rcu() NeilBrown
2018-12-03 0:30 ` [PATCH 10/23] NFSv4: don't require lock for get_renew_cred or get_machine_cred NeilBrown
2018-12-03 0:30 ` [PATCH 17/23] NFS: change access cache to use 'struct cred' NeilBrown
2018-12-03 0:30 ` [PATCH 01/23] cred: add cred_fscmp() for comparing creds NeilBrown
2018-12-03 0:30 ` [PATCH 23/23] SUNRPC discard cr_uid from struct rpc_cred NeilBrown
2018-12-03 0:30 ` [PATCH 22/23] SUNRPC: simplify auth_unix NeilBrown
2018-12-03 0:30 ` [PATCH 19/23] NFS/NFSD/SUNRPC: replace generic creds with 'struct cred' NeilBrown
2018-12-03 0:30 ` [PATCH 20/23] SUNRPC: remove generic cred code NeilBrown
2018-12-03 0:30 ` [PATCH 21/23] SUNRPC: remove crbind rpc_cred operation NeilBrown
2018-12-04 20:21 ` [PATCH 00/23 - V5] NFS: Remove generic RPC credentials J. Bruce Fields
2018-12-04 21:33 ` Schumaker, Anna
2018-12-05 1:47 ` bfields
-- strict thread matches above, loose matches on Subject: below --
2018-11-07 4:12 [PATCH 00/23 - V4] " NeilBrown
2018-11-07 4:12 ` [PATCH 04/23] cred: allow get_cred() and put_cred() to be given NULL NeilBrown
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