[PATCH 15/23] NFS: move credential expiry tracking out of SUNRPC into NFS.
From: NeilBrown
Date: Tue Nov 06 2018 - 23:15:11 EST
NFS needs to know when a credential is about to expire so that
it can modify write-back behaviour to finish the write inside the
expiry time.
It currently uses functions in SUNRPC code which make use of a
fairly complex callback scheme and flags in the generic credientials.
As I am working to discard the generic credentials, this has to change.
This patch moves the logic into NFS, in part by finding and caching
the low-level credential in the open_context. We then make direct
cred-api calls on that.
This makes the code much simpler and removes a dependency on generic
rpc credentials.
Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
fs/nfs/inode.c | 2 +
fs/nfs/write.c | 24 +++++++++++--
include/linux/nfs_fs.h | 1 +
include/linux/sunrpc/auth.h | 12 ------
net/sunrpc/auth.c | 23 ------------
net/sunrpc/auth_generic.c | 75 ----------------------------------------
net/sunrpc/auth_gss/auth_gss.c | 21 ++---------
7 files changed, 28 insertions(+), 130 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 5b1eee4952b7..aea015743172 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -962,6 +962,7 @@ struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
nfs_sb_active(dentry->d_sb);
ctx->dentry = dget(dentry);
ctx->cred = cred;
+ ctx->ll_cred = NULL;
ctx->state = NULL;
ctx->mode = f_mode;
ctx->flags = 0;
@@ -1001,6 +1002,7 @@ static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
put_rpccred(ctx->cred);
dput(ctx->dentry);
nfs_sb_deactive(sb);
+ put_rpccred(ctx->ll_cred);
kfree(ctx->mdsthreshold);
kfree_rcu(ctx, rcu_head);
}
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 586726a590d8..c1452f838131 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1233,9 +1233,12 @@ int
nfs_key_timeout_notify(struct file *filp, struct inode *inode)
{
struct nfs_open_context *ctx = nfs_file_open_context(filp);
- struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
- return rpcauth_key_timeout_notify(auth, ctx->cred);
+ if (nfs_ctx_key_to_expire(ctx, inode) &&
+ !ctx->ll_cred)
+ /* Already expired! */
+ return -EACCES;
+ return 0;
}
/*
@@ -1244,8 +1247,23 @@ nfs_key_timeout_notify(struct file *filp, struct inode *inode)
bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode)
{
struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
+ struct rpc_cred *cred = ctx->ll_cred;
+ struct auth_cred acred = {
+ .cred = ctx->cred->cr_cred,
+ };
- return rpcauth_cred_key_to_expire(auth, ctx->cred);
+ if (cred && !cred->cr_ops->crmatch(&acred, cred, 0)) {
+ put_rpccred(cred);
+ ctx->ll_cred = NULL;
+ cred = NULL;
+ }
+ if (!cred)
+ cred = auth->au_ops->lookup_cred(auth, &acred, 0);
+ if (!cred || IS_ERR(cred))
+ return true;
+ ctx->ll_cred = cred;
+ return !!(cred->cr_ops->crkey_timeout &&
+ cred->cr_ops->crkey_timeout(cred));
}
/*
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 6e0417c02279..ecf22c0034d5 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -71,6 +71,7 @@ struct nfs_open_context {
fl_owner_t flock_owner;
struct dentry *dentry;
struct rpc_cred *cred;
+ struct rpc_cred *ll_cred; /* low-level cred - use to check for expiry */
struct nfs4_state *state;
fmode_t mode;
diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 28b34c740c43..0bdc2f4957ff 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -37,17 +37,9 @@
struct rpcsec_gss_info;
-/* auth_cred ac_flags bits */
-enum {
- RPC_CRED_KEY_EXPIRE_SOON = 1, /* underlying cred key will expire soon */
- RPC_CRED_NOTIFY_TIMEOUT = 2, /* nofity generic cred when underlying
- key will expire soon */
-};
-
struct auth_cred {
const struct cred *cred;
const char *principal; /* If present, this is a machine credential */
- unsigned long ac_flags;
};
/*
@@ -154,7 +146,6 @@ struct rpc_credops {
int (*crunwrap_resp)(struct rpc_task *, kxdrdproc_t,
void *, __be32 *, void *);
int (*crkey_timeout)(struct rpc_cred *);
- bool (*crkey_to_expire)(struct rpc_cred *);
char * (*crstringify_acceptor)(struct rpc_cred *);
bool (*crneed_reencode)(struct rpc_task *);
};
@@ -198,9 +189,6 @@ int rpcauth_uptodatecred(struct rpc_task *);
int rpcauth_init_credcache(struct rpc_auth *);
void rpcauth_destroy_credcache(struct rpc_auth *);
void rpcauth_clear_credcache(struct rpc_cred_cache *);
-int rpcauth_key_timeout_notify(struct rpc_auth *,
- struct rpc_cred *);
-bool rpcauth_cred_key_to_expire(struct rpc_auth *, struct rpc_cred *);
char * rpcauth_stringify_acceptor(struct rpc_cred *);
static inline
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 27d90578e7a0..cf23eed01b1c 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -360,29 +360,6 @@ rpcauth_init_credcache(struct rpc_auth *auth)
}
EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
-/*
- * Setup a credential key lifetime timeout notification
- */
-int
-rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
-{
- if (!cred->cr_auth->au_ops->key_timeout)
- return 0;
- return cred->cr_auth->au_ops->key_timeout(auth, cred);
-}
-EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
-
-bool
-rpcauth_cred_key_to_expire(struct rpc_auth *auth, struct rpc_cred *cred)
-{
- if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
- return false;
- if (!cred->cr_ops->crkey_to_expire)
- return false;
- return cred->cr_ops->crkey_to_expire(cred);
-}
-EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
-
char *
rpcauth_stringify_acceptor(struct rpc_cred *cred)
{
diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
index 8cf5aa515c51..c57e83184d3c 100644
--- a/net/sunrpc/auth_generic.c
+++ b/net/sunrpc/auth_generic.c
@@ -87,7 +87,6 @@ generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, g
gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
gcred->acred.cred = gcred->gc_base.cr_cred;
- gcred->acred.ac_flags = 0;
gcred->acred.principal = acred->principal;
dprintk("RPC: allocated %s cred %p for uid %d gid %d\n",
@@ -179,72 +178,12 @@ void rpc_destroy_generic_auth(void)
rpcauth_destroy_credcache(&generic_auth);
}
-/*
- * Test the the current time (now) against the underlying credential key expiry
- * minus a timeout and setup notification.
- *
- * The normal case:
- * If 'now' is before the key expiry minus RPC_KEY_EXPIRE_TIMEO, set
- * the RPC_CRED_NOTIFY_TIMEOUT flag to setup the underlying credential
- * rpc_credops crmatch routine to notify this generic cred when it's key
- * expiration is within RPC_KEY_EXPIRE_TIMEO, and return 0.
- *
- * The error case:
- * If the underlying cred lookup fails, return -EACCES.
- *
- * The 'almost' error case:
- * If 'now' is within key expiry minus RPC_KEY_EXPIRE_TIMEO, but not within
- * key expiry minus RPC_KEY_EXPIRE_FAIL, set the RPC_CRED_EXPIRE_SOON bit
- * on the acred ac_flags and return 0.
- */
-static int
-generic_key_timeout(struct rpc_auth *auth, struct rpc_cred *cred)
-{
- struct auth_cred *acred = &container_of(cred, struct generic_cred,
- gc_base)->acred;
- struct rpc_cred *tcred;
- int ret = 0;
-
-
- /* Fast track for non crkey_timeout (no key) underlying credentials */
- if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
- return 0;
-
- /* Fast track for the normal case */
- if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags))
- return 0;
-
- /* lookup_cred either returns a valid referenced rpc_cred, or PTR_ERR */
- tcred = auth->au_ops->lookup_cred(auth, acred, 0);
- if (IS_ERR(tcred))
- return -EACCES;
-
- /* Test for the almost error case */
- ret = tcred->cr_ops->crkey_timeout(tcred);
- if (ret != 0) {
- set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
- ret = 0;
- } else {
- /* In case underlying cred key has been reset */
- if (test_and_clear_bit(RPC_CRED_KEY_EXPIRE_SOON,
- &acred->ac_flags))
- dprintk("RPC: UID %d Credential key reset\n",
- from_kuid(&init_user_ns, tcred->cr_uid));
- /* set up fasttrack for the normal case */
- set_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
- }
-
- put_rpccred(tcred);
- return ret;
-}
-
static const struct rpc_authops generic_auth_ops = {
.owner = THIS_MODULE,
.au_name = "Generic",
.hash_cred = generic_hash_cred,
.lookup_cred = generic_lookup_cred,
.crcreate = generic_create_cred,
- .key_timeout = generic_key_timeout,
};
static struct rpc_auth generic_auth = {
@@ -252,23 +191,9 @@ static struct rpc_auth generic_auth = {
.au_count = REFCOUNT_INIT(1),
};
-static bool generic_key_to_expire(struct rpc_cred *cred)
-{
- struct auth_cred *acred = &container_of(cred, struct generic_cred,
- gc_base)->acred;
- bool ret;
-
- get_rpccred(cred);
- ret = test_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
- put_rpccred(cred);
-
- return ret;
-}
-
static const struct rpc_credops generic_credops = {
.cr_name = "Generic cred",
.crdestroy = generic_destroy_cred,
.crbind = generic_bind_cred,
.crmatch = generic_match,
- .crkey_to_expire = generic_key_to_expire,
};
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index feea8e65797c..7c5311c2f524 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1494,23 +1494,10 @@ gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
if (gss_cred->gc_principal == NULL)
return 0;
ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
- goto check_expire;
- }
- if (gss_cred->gc_principal != NULL)
- return 0;
- ret = uid_eq(rc->cr_uid, acred->cred->fsuid);
-
-check_expire:
- if (ret == 0)
- return ret;
-
- /* Notify acred users of GSS context expiration timeout */
- if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
- (gss_key_timeout(rc) != 0)) {
- /* test will now be done from generic cred */
- test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
- /* tell NFS layer that key will expire soon */
- set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
+ } else {
+ if (gss_cred->gc_principal != NULL)
+ return 0;
+ ret = uid_eq(rc->cr_uid, acred->cred->fsuid);
}
return ret;
}