From 2edd8d746e51229705367528e95e5b49bccfa76e Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 3 Dec 2018 11:30:31 +1100 Subject: [PATCH] SUNRPC: simplify auth_unix. 1/ discard 'struct unx_cred'. We don't need any data that is not already in 'struct rpc_cred'. 2/ Don't keep these creds in a hash table. When a credential is needed, simply allocate it. When not needed, discard it. This can easily be faster than performing a lookup on a shared hash table. As the lookup can happen during write-out, use a mempool to ensure forward progress. This means that we cannot compare two credentials for equality by comparing the pointers, but we never do that anyway. Signed-off-by: NeilBrown Signed-off-by: Anna Schumaker --- net/sunrpc/auth.c | 1 + net/sunrpc/auth_unix.c | 103 +++++++++++++---------------------------- 2 files changed, 33 insertions(+), 71 deletions(-) diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index 867ea9834bde..a07a7c59d3a4 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -651,6 +651,7 @@ rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred, INIT_LIST_HEAD(&cred->cr_lru); refcount_set(&cred->cr_count, 1); cred->cr_auth = auth; + cred->cr_flags = 0; cred->cr_ops = ops; cred->cr_expire = jiffies; cred->cr_cred = get_cred(acred->cred); diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c index bff113a411e0..387f6b3ffbea 100644 --- a/net/sunrpc/auth_unix.c +++ b/net/sunrpc/auth_unix.c @@ -11,16 +11,11 @@ #include #include #include +#include #include #include #include -struct unx_cred { - struct rpc_cred uc_base; - kgid_t uc_gid; - kgid_t uc_gids[UNX_NGROUPS]; -}; -#define uc_uid uc_base.cr_uid #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) # define RPCDBG_FACILITY RPCDBG_AUTH @@ -28,6 +23,7 @@ struct unx_cred { static struct rpc_auth unix_auth; static const struct rpc_credops unix_credops; +static mempool_t *unix_pool; static struct rpc_auth * unx_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt) @@ -42,15 +38,6 @@ static void unx_destroy(struct rpc_auth *auth) { dprintk("RPC: destroying UNIX authenticator %p\n", auth); - rpcauth_clear_credcache(auth->au_credcache); -} - -static int -unx_hash_cred(struct auth_cred *acred, unsigned int hashbits) -{ - return hash_64(from_kgid(&init_user_ns, acred->cred->fsgid) | - ((u64)from_kuid(&init_user_ns, acred->cred->fsuid) << - (sizeof(gid_t) * 8)), hashbits); } /* @@ -59,53 +46,24 @@ unx_hash_cred(struct auth_cred *acred, unsigned int hashbits) static struct rpc_cred * unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) { - return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS); -} - -static struct rpc_cred * -unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp) -{ - struct unx_cred *cred; - unsigned int groups = 0; - unsigned int i; + struct rpc_cred *ret = mempool_alloc(unix_pool, GFP_NOFS); dprintk("RPC: allocating UNIX cred for uid %d gid %d\n", from_kuid(&init_user_ns, acred->cred->fsuid), from_kgid(&init_user_ns, acred->cred->fsgid)); - if (!(cred = kmalloc(sizeof(*cred), gfp))) - return ERR_PTR(-ENOMEM); - - rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops); - cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE; - - if (acred->cred && acred->cred->group_info != NULL) - groups = acred->cred->group_info->ngroups; - if (groups > UNX_NGROUPS) - groups = UNX_NGROUPS; - - cred->uc_gid = acred->cred->fsgid; - for (i = 0; i < groups; i++) - cred->uc_gids[i] = acred->cred->group_info->gid[i]; - if (i < UNX_NGROUPS) - cred->uc_gids[i] = INVALID_GID; - - return &cred->uc_base; -} - -static void -unx_free_cred(struct unx_cred *unx_cred) -{ - dprintk("RPC: unx_free_cred %p\n", unx_cred); - put_cred(unx_cred->uc_base.cr_cred); - kfree(unx_cred); + rpcauth_init_cred(ret, acred, auth, &unix_credops); + ret->cr_flags = 1UL << RPCAUTH_CRED_UPTODATE; + return ret; } static void unx_free_cred_callback(struct rcu_head *head) { - struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu); - unx_free_cred(unx_cred); + struct rpc_cred *rpc_cred = container_of(head, struct rpc_cred, cr_rcu); + dprintk("RPC: unx_free_cred %p\n", rpc_cred); + put_cred(rpc_cred->cr_cred); + mempool_free(rpc_cred, unix_pool); } static void @@ -115,30 +73,32 @@ unx_destroy_cred(struct rpc_cred *cred) } /* - * Match credentials against current process creds. - * The root_override argument takes care of cases where the caller may - * request root creds (e.g. for NFS swapping). + * Match credentials against current the auth_cred. */ static int -unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags) +unx_match(struct auth_cred *acred, struct rpc_cred *cred, int flags) { - struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base); unsigned int groups = 0; unsigned int i; + if (cred->cr_cred == acred->cred) + return 1; - if (!uid_eq(cred->uc_uid, acred->cred->fsuid) || !gid_eq(cred->uc_gid, acred->cred->fsgid)) + if (!uid_eq(cred->cr_cred->fsuid, acred->cred->fsuid) || !gid_eq(cred->cr_cred->fsgid, acred->cred->fsgid)) return 0; if (acred->cred && acred->cred->group_info != NULL) groups = acred->cred->group_info->ngroups; if (groups > UNX_NGROUPS) groups = UNX_NGROUPS; - for (i = 0; i < groups ; i++) - if (!gid_eq(cred->uc_gids[i], acred->cred->group_info->gid[i])) - return 0; - if (groups < UNX_NGROUPS && gid_valid(cred->uc_gids[groups])) + if (cred->cr_cred->group_info == NULL) + return groups == 0; + if (groups != cred->cr_cred->group_info->ngroups) return 0; + + for (i = 0; i < groups ; i++) + if (!gid_eq(cred->cr_cred->group_info->gid[i], acred->cred->group_info->gid[i])) + return 0; return 1; } @@ -150,9 +110,10 @@ static __be32 * unx_marshal(struct rpc_task *task, __be32 *p) { struct rpc_clnt *clnt = task->tk_client; - struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base); + struct rpc_cred *cred = task->tk_rqstp->rq_cred; __be32 *base, *hold; int i; + struct group_info *gi = cred->cr_cred->group_info; *p++ = htonl(RPC_AUTH_UNIX); base = p++; @@ -163,11 +124,12 @@ unx_marshal(struct rpc_task *task, __be32 *p) */ p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); - *p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid)); - *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid)); + *p++ = htonl((u32) from_kuid(&init_user_ns, cred->cr_cred->fsuid)); + *p++ = htonl((u32) from_kgid(&init_user_ns, cred->cr_cred->fsgid)); hold = p++; - for (i = 0; i < UNX_NGROUPS && gid_valid(cred->uc_gids[i]); i++) - *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i])); + if (gi) + for (i = 0; i < UNX_NGROUPS && i < gi->ngroups; i++) + *p++ = htonl((u32) from_kgid(&init_user_ns, gi->gid[i])); *hold = htonl(p - hold - 1); /* gid array length */ *base = htonl((p - base - 1) << 2); /* cred length */ @@ -214,12 +176,13 @@ unx_validate(struct rpc_task *task, __be32 *p) int __init rpc_init_authunix(void) { - return rpcauth_init_credcache(&unix_auth); + unix_pool = mempool_create_kmalloc_pool(16, sizeof(struct rpc_cred)); + return unix_pool ? 0 : -ENOMEM; } void rpc_destroy_authunix(void) { - rpcauth_destroy_credcache(&unix_auth); + mempool_destroy(unix_pool); } const struct rpc_authops authunix_ops = { @@ -228,9 +191,7 @@ const struct rpc_authops authunix_ops = { .au_name = "UNIX", .create = unx_create, .destroy = unx_destroy, - .hash_cred = unx_hash_cred, .lookup_cred = unx_lookup_cred, - .crcreate = unx_create_cred, }; static