The SUNRPC credential framework was put together before
Linux has 'struct cred'. Now that we have it, it makes sense to
use it.
This first step just includes a suitable 'struct cred *' pointer
in every 'struct auth_cred' and almost every 'struct rpc_cred'.
The rpc_cred used for auth_null has a NULL 'struct cred *' as nothing
else really makes sense.
For rpc_cred, the pointer is reference counted.
For auth_cred it isn't. struct auth_cred are either allocated on
the stack, in which case the thread owns a reference to the auth,
or are part of 'struct generic_cred' in which case gc_base owns the
reference and acred shares it.
Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
fs/nfs/flexfilelayout/flexfilelayout.c | 17 +++++++++++++++++
fs/nfsd/nfs4callback.c | 13 ++++++++++++-
include/linux/sunrpc/auth.h | 2 ++
net/sunrpc/auth.c | 15 +++++++++++++--
net/sunrpc/auth_generic.c | 7 ++++++-
net/sunrpc/auth_gss/auth_gss.c | 1 +
6 files changed, 51 insertions(+), 4 deletions(-)
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index c75ad982bcfc..b727579a1508 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -9,6 +9,7 @@
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/module.h>
+#include <linux/sched/mm.h>
#include <linux/sunrpc/metrics.h>
@@ -415,6 +416,7 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
struct nfs4_ff_layout_mirror *mirror;
struct auth_cred acred = { .group_info = ff_zero_group };
struct rpc_cred __rcu *cred;
+ struct cred *kcred;
u32 ds_count, fh_count, id;
int j;
@@ -491,8 +493,23 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
acred.gid = make_kgid(&init_user_ns, id);
+ if (gfp_flags & __GFP_FS)
+ kcred = prepare_kernel_cred(NULL);
+ else {
+ unsigned int nofs_flags = memalloc_nofs_save();
+ kcred = prepare_kernel_cred(NULL);
+ memalloc_nofs_restore(nofs_flags);
+ }
+ rc = -ENOMEM;
+ if (!kcred)
+ goto out_err_free;
+ kcred->fsuid = acred.uid;
+ kcred->fsgid = acred.gid;
+ acred.cred = kcred;
+
/* find the cred for it */
rcu_assign_pointer(cred, rpc_lookup_generic_cred(&acred, 0, gfp_flags));
+ put_cred(kcred);
if (IS_ERR(cred)) {
rc = PTR_ERR(cred);
goto out_err_free;
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 49b0a9e7ff18..fc5b38ee6c70 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -773,10 +773,21 @@ static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc
} else {
struct rpc_auth *auth = client->cl_auth;
struct auth_cred acred = {};
+ struct cred *kcred;
+ struct rpc_cred *ret;
+
+ kcred = prepare_kernel_cred(NULL);
+ if (!acred.cred)
+ return NULL;
acred.uid = ses->se_cb_sec.uid;
acred.gid = ses->se_cb_sec.gid;
- return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
+ kcred->uid = acred.uid;
+ kcred->gid = acred.gid;
+ acred.cred = kcred;
+ ret = auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
+ put_cred(kcred);
+ return ret;
}
}
diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index d9af474a857d..57633e241d4a 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -46,6 +46,7 @@ enum {
/* Work around the lack of a VFS credential */
struct auth_cred {
+ const struct cred *cred;
kuid_t uid;
kgid_t gid;
struct group_info *group_info;
@@ -68,6 +69,7 @@ struct rpc_cred {
unsigned long cr_expire; /* when to gc */
unsigned long cr_flags; /* various flags */
atomic_t cr_count; /* ref count */
+ const struct cred *cr_cred;
kuid_t cr_uid;
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index d2623b9f23d6..fd9635dbc17f 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -634,6 +634,7 @@ rpcauth_lookupcred(struct rpc_auth *auth, int flags)
acred.uid = cred->fsuid;
acred.gid = cred->fsgid;
acred.group_info = cred->group_info;
+ acred.cred = cred;
ret = auth->au_ops->lookup_cred(auth, &acred, flags);
return ret;
}
@@ -649,6 +650,7 @@ rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
cred->cr_auth = auth;
cred->cr_ops = ops;
cred->cr_expire = jiffies;
+ cred->cr_cred = get_cred(acred->cred);
cred->cr_uid = acred->uid;
}
EXPORT_SYMBOL_GPL(rpcauth_init_cred);
@@ -669,11 +671,15 @@ rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
struct auth_cred acred = {
.uid = GLOBAL_ROOT_UID,
.gid = GLOBAL_ROOT_GID,
+ .cred = get_task_cred(&init_task),
};
+ struct rpc_cred *ret;
dprintk("RPC: %5u looking up %s cred\n",
task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
- return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
+ ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
+ put_cred(acred.cred);
+ return ret;
}
static struct rpc_cred *
@@ -715,8 +721,11 @@ put_rpccred(struct rpc_cred *cred)
return;
/* Fast path for unhashed credentials */
if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
- if (atomic_dec_and_test(&cred->cr_count))
+ if (atomic_dec_and_test(&cred->cr_count)) {
+ if (cred->cr_cred)
+ put_cred(cred->cr_cred);
cred->cr_ops->crdestroy(cred);
+ }
return;
}
@@ -739,6 +748,8 @@ put_rpccred(struct rpc_cred *cred)
}
}
spin_unlock(&rpc_credcache_lock);
+ if (cred->cr_cred)
+ put_cred(cred->cr_cred);
cred->cr_ops->crdestroy(cred);
return;
out_nodestroy:
diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
index f1df9837f1ac..08bc5fac1865 100644
--- a/net/sunrpc/auth_generic.c
+++ b/net/sunrpc/auth_generic.c
@@ -61,11 +61,15 @@ struct rpc_cred *rpc_lookup_machine_cred(const char *service_name)
.gid = RPC_MACHINE_CRED_GROUPID,
.principal = service_name,
.machine_cred = 1,
+ .cred = get_task_cred(&init_task),
};
+ struct rpc_cred *ret;
dprintk("RPC: looking up machine cred for service %s\n",
service_name);
- return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
+ ret = generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
+ put_cred(acred.cred);
+ return ret;
}
EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
@@ -110,6 +114,7 @@ generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, g
gcred->acred.uid = acred->uid;
gcred->acred.gid = acred->gid;
gcred->acred.group_info = acred->group_info;
+ gcred->acred.cred = gcred->gc_base.cr_cred;
gcred->acred.ac_flags = 0;
if (gcred->acred.group_info != NULL)
get_group_info(gcred->acred.group_info);
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 9463af4b32e8..82301105b4f6 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1553,6 +1553,7 @@ static int gss_renew_cred(struct rpc_task *task)
struct rpc_auth *auth = oldcred->cr_auth;
struct auth_cred acred = {
.uid = oldcred->cr_uid,
+ .cred = oldcred->cr_cred,
.principal = gss_cred->gc_principal,
.machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
};
--
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