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Commit 5d28dc82 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Convert gss_ctx_lock to an RCU lock 



Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent f5c2187c

include/linux/sunrpc/auth_gss.h

+1 −0
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ struct gss_cl_ctx { 
	struct xdr_netobj	gc_wire_ctx;

	u32			gc_win;

	unsigned long		gc_expiry;

	struct rcu_head		gc_rcu;

};



struct gss_upcall_msg;

net/sunrpc/auth_gss/auth_gss.c

+36 −17
Original line number Diff line number Diff line
@@ -78,8 +78,6 @@ static const struct rpc_credops gss_credops; 
/* dump the buffer in `emacs-hexl' style */

#define isprint(c)      ((c > 0x1f) && (c < 0x7f))



static DEFINE_RWLOCK(gss_ctx_lock);



struct gss_auth {

	struct rpc_auth rpc_auth;

	struct gss_api_mech *mech;
@@ -88,7 +86,7 @@ struct gss_auth { 
	struct dentry *dentry;

};



static void gss_destroy_ctx(struct gss_cl_ctx *);

static void gss_free_ctx(struct gss_cl_ctx *);

static struct rpc_pipe_ops gss_upcall_ops;



static inline struct gss_cl_ctx *
@@ -102,20 +100,24 @@ static inline void 
gss_put_ctx(struct gss_cl_ctx *ctx)

{

	if (atomic_dec_and_test(&ctx->count))

		gss_destroy_ctx(ctx);

		gss_free_ctx(ctx);

}



/* gss_cred_set_ctx:

 * called by gss_upcall_callback and gss_create_upcall in order

 * to set the gss context. The actual exchange of an old context

 * and a new one is protected by the inode->i_lock.

 */

static void

gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)

{

	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);

	struct gss_cl_ctx *old;

	write_lock(&gss_ctx_lock);



	old = gss_cred->gc_ctx;

	gss_cred->gc_ctx = ctx;

	rcu_assign_pointer(gss_cred->gc_ctx, ctx);

	set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);

	clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);

	write_unlock(&gss_ctx_lock);

	if (old)

		gss_put_ctx(old);

}
@@ -126,10 +128,10 @@ gss_cred_is_uptodate_ctx(struct rpc_cred *cred) 
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);

	int res = 0;



	read_lock(&gss_ctx_lock);

	rcu_read_lock();

	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) && gss_cred->gc_ctx)

		res = 1;

	read_unlock(&gss_ctx_lock);

	rcu_read_unlock();

	return res;

}
@@ -168,10 +170,10 @@ gss_cred_get_ctx(struct rpc_cred *cred) 
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);

	struct gss_cl_ctx *ctx = NULL;



	read_lock(&gss_ctx_lock);

	rcu_read_lock();

	if (gss_cred->gc_ctx)

		ctx = gss_get_ctx(gss_cred->gc_ctx);

	read_unlock(&gss_ctx_lock);

	rcu_read_unlock();

	return ctx;

}
@@ -333,11 +335,11 @@ gss_upcall_callback(struct rpc_task *task) 
	struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;

	struct inode *inode = gss_msg->auth->dentry->d_inode;



	spin_lock(&inode->i_lock);

	if (gss_msg->ctx)

		gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx));

	else

		task->tk_status = gss_msg->msg.errno;

	spin_lock(&inode->i_lock);

	gss_cred->gc_upcall = NULL;

	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);

	spin_unlock(&inode->i_lock);
@@ -440,7 +442,6 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred) 
		prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);

		spin_lock(&inode->i_lock);

		if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {

			spin_unlock(&inode->i_lock);

			break;

		}

		spin_unlock(&inode->i_lock);
@@ -454,6 +455,7 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred) 
		gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));

	else

		err = gss_msg->msg.errno;

	spin_unlock(&inode->i_lock);

out_intr:

	finish_wait(&gss_msg->waitqueue, &wait);

	gss_release_msg(gss_msg);
@@ -681,9 +683,9 @@ gss_destroy(struct rpc_auth *auth) 
 * to create a new cred or context, so they check that things have been

 * allocated before freeing them. */

static void

gss_destroy_ctx(struct gss_cl_ctx *ctx)

gss_do_free_ctx(struct gss_cl_ctx *ctx)

{

	dprintk("RPC:       gss_destroy_ctx\n");

	dprintk("RPC:       gss_free_ctx\n");



	if (ctx->gc_gss_ctx)

		gss_delete_sec_context(&ctx->gc_gss_ctx);
@@ -692,12 +694,23 @@ gss_destroy_ctx(struct gss_cl_ctx *ctx) 
	kfree(ctx);

}



static void

gss_free_ctx_callback(struct rcu_head *head)

{

	struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);

	gss_do_free_ctx(ctx);

}



static void

gss_free_ctx(struct gss_cl_ctx *ctx)

{

	call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);

}



static void

gss_free_cred(struct gss_cred *gss_cred)

{

	dprintk("RPC:       gss_free_cred %p\n", gss_cred);

	if (gss_cred->gc_ctx)

		gss_put_ctx(gss_cred->gc_ctx);

	kfree(gss_cred);

}
@@ -711,7 +724,13 @@ gss_free_cred_callback(struct rcu_head *head) 
static void

gss_destroy_cred(struct rpc_cred *cred)

{

	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);

	struct gss_cl_ctx *ctx = gss_cred->gc_ctx;



	rcu_assign_pointer(gss_cred->gc_ctx, NULL);

	call_rcu(&cred->cr_rcu, gss_free_cred_callback);

	if (ctx)

		gss_put_ctx(ctx);

}



/*