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Commit 2edd8d74 authored by NeilBrown's avatar NeilBrown Committed by Anna Schumaker
Browse files

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: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent d6efccd9

net/sunrpc/auth.c

+1 −0
Original line number Diff line number Diff line
@@ -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);

net/sunrpc/auth_unix.c

+31 −70
Original line number Diff line number Diff line
@@ -11,16 +11,11 @@ 
#include <linux/types.h>

#include <linux/sched.h>

#include <linux/module.h>

#include <linux/mempool.h>

#include <linux/sunrpc/clnt.h>

#include <linux/sunrpc/auth.h>

#include <linux/user_namespace.h>



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
@@ -115,29 +73,31 @@ 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]))

	if (cred->cr_cred->group_info == NULL)

		return groups == 0;

	if (groups != cred->cr_cred->group_info->ngroups)

		return 0;

	if (groups < UNX_NGROUPS && gid_valid(cred->uc_gids[groups]))



	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