1 files changed, 333 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/llite/remote_perm.c b/drivers/staging/lustre/lustre/llite/remote_perm.c
new file mode 100644
index 000000000000..68b2dc4a7b62
--- /dev/null
+++ b/drivers/staging/lustre/lustre/llite/remote_perm.c
@@ -0,0 +1,333 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/llite/remote_perm.c
+ *
+ * Lustre Permission Cache for Remote Client
+ *
+ * Author: Lai Siyao <lsy@clusterfs.com>
+ * Author: Fan Yong <fanyong@clusterfs.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_LLITE
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+#include <lustre_lite.h>
+#include <lustre_ha.h>
+#include <lustre_dlm.h>
+#include <lprocfs_status.h>
+#include <lustre_disk.h>
+#include <lustre_param.h>
+#include "llite_internal.h"
+
+struct kmem_cache *ll_remote_perm_cachep = NULL;
+struct kmem_cache *ll_rmtperm_hash_cachep = NULL;
+
+static inline struct ll_remote_perm *alloc_ll_remote_perm(void)
+{
+	struct ll_remote_perm *lrp;
+
+	OBD_SLAB_ALLOC_PTR_GFP(lrp, ll_remote_perm_cachep, GFP_KERNEL);
+	if (lrp)
+		INIT_HLIST_NODE(&lrp->lrp_list);
+	return lrp;
+}
+
+static inline void free_ll_remote_perm(struct ll_remote_perm *lrp)
+{
+	if (!lrp)
+		return;
+
+	if (!hlist_unhashed(&lrp->lrp_list))
+		hlist_del(&lrp->lrp_list);
+	OBD_SLAB_FREE(lrp, ll_remote_perm_cachep, sizeof(*lrp));
+}
+
+struct hlist_head *alloc_rmtperm_hash(void)
+{
+	struct hlist_head *hash;
+	int i;
+
+	OBD_SLAB_ALLOC_GFP(hash, ll_rmtperm_hash_cachep,
+			   REMOTE_PERM_HASHSIZE * sizeof(*hash),
+			   GFP_IOFS);
+	if (!hash)
+		return NULL;
+
+	for (i = 0; i < REMOTE_PERM_HASHSIZE; i++)
+		INIT_HLIST_HEAD(hash + i);
+
+	return hash;
+}
+
+void free_rmtperm_hash(struct hlist_head *hash)
+{
+	int i;
+	struct ll_remote_perm *lrp;
+	struct hlist_node *next;
+
+	if(!hash)
+		return;
+
+	for (i = 0; i < REMOTE_PERM_HASHSIZE; i++)
+		hlist_for_each_entry_safe(lrp, next, hash + i,
+					      lrp_list)
+			free_ll_remote_perm(lrp);
+	OBD_SLAB_FREE(hash, ll_rmtperm_hash_cachep,
+		      REMOTE_PERM_HASHSIZE * sizeof(*hash));
+}
+
+static inline int remote_perm_hashfunc(uid_t uid)
+{
+	return uid & (REMOTE_PERM_HASHSIZE - 1);
+}
+
+/* NB: setxid permission is not checked here, instead it's done on
+ * MDT when client get remote permission. */
+static int do_check_remote_perm(struct ll_inode_info *lli, int mask)
+{
+	struct hlist_head *head;
+	struct ll_remote_perm *lrp;
+	int found = 0, rc;
+	ENTRY;
+
+	if (!lli->lli_remote_perms)
+		RETURN(-ENOENT);
+
+	head = lli->lli_remote_perms + remote_perm_hashfunc(current_uid());
+
+	spin_lock(&lli->lli_lock);
+	hlist_for_each_entry(lrp, head, lrp_list) {
+		if (lrp->lrp_uid != current_uid())
+			continue;
+		if (lrp->lrp_gid != current_gid())
+			continue;
+		if (lrp->lrp_fsuid != current_fsuid())
+			continue;
+		if (lrp->lrp_fsgid != current_fsgid())
+			continue;
+		found = 1;
+		break;
+	}
+
+	if (!found)
+		GOTO(out, rc = -ENOENT);
+
+	CDEBUG(D_SEC, "found remote perm: %u/%u/%u/%u - %#x\n",
+	       lrp->lrp_uid, lrp->lrp_gid, lrp->lrp_fsuid, lrp->lrp_fsgid,
+	       lrp->lrp_access_perm);
+	rc = ((lrp->lrp_access_perm & mask) == mask) ? 0 : -EACCES;
+
+out:
+	spin_unlock(&lli->lli_lock);
+	return rc;
+}
+
+int ll_update_remote_perm(struct inode *inode, struct mdt_remote_perm *perm)
+{
+	struct ll_inode_info *lli = ll_i2info(inode);
+	struct ll_remote_perm *lrp = NULL, *tmp = NULL;
+	struct hlist_head *head, *perm_hash = NULL;
+	ENTRY;
+
+	LASSERT(ll_i2sbi(inode)->ll_flags & LL_SBI_RMT_CLIENT);
+
+#if 0
+	if (perm->rp_uid != current->uid ||
+	    perm->rp_gid != current->gid ||
+	    perm->rp_fsuid != current->fsuid ||
+	    perm->rp_fsgid != current->fsgid) {
+		/* user might setxid in this small period */
+		CDEBUG(D_SEC,
+		       "remote perm user %u/%u/%u/%u != current %u/%u/%u/%u\n",
+		       perm->rp_uid, perm->rp_gid, perm->rp_fsuid,
+		       perm->rp_fsgid, current->uid, current->gid,
+		       current->fsuid, current->fsgid);
+		RETURN(-EAGAIN);
+	}
+#endif
+
+	if (!lli->lli_remote_perms) {
+		perm_hash = alloc_rmtperm_hash();
+		if (perm_hash == NULL) {
+			CERROR("alloc lli_remote_perms failed!\n");
+			RETURN(-ENOMEM);
+		}
+	}
+
+	spin_lock(&lli->lli_lock);
+
+	if (!lli->lli_remote_perms)
+		lli->lli_remote_perms = perm_hash;
+	else if (perm_hash)
+		free_rmtperm_hash(perm_hash);
+
+	head = lli->lli_remote_perms + remote_perm_hashfunc(perm->rp_uid);
+
+again:
+	hlist_for_each_entry(tmp, head, lrp_list) {
+		if (tmp->lrp_uid != perm->rp_uid)
+			continue;
+		if (tmp->lrp_gid != perm->rp_gid)
+			continue;
+		if (tmp->lrp_fsuid != perm->rp_fsuid)
+			continue;
+		if (tmp->lrp_fsgid != perm->rp_fsgid)
+			continue;
+		if (lrp)
+			free_ll_remote_perm(lrp);
+		lrp = tmp;
+		break;
+	}
+
+	if (!lrp) {
+		spin_unlock(&lli->lli_lock);
+		lrp = alloc_ll_remote_perm();
+		if (!lrp) {
+			CERROR("alloc memory for ll_remote_perm failed!\n");
+			RETURN(-ENOMEM);
+		}
+		spin_lock(&lli->lli_lock);
+		goto again;
+	}
+
+	lrp->lrp_access_perm = perm->rp_access_perm;
+	if (lrp != tmp) {
+		lrp->lrp_uid	 = perm->rp_uid;
+		lrp->lrp_gid	 = perm->rp_gid;
+		lrp->lrp_fsuid       = perm->rp_fsuid;
+		lrp->lrp_fsgid       = perm->rp_fsgid;
+		hlist_add_head(&lrp->lrp_list, head);
+	}
+	lli->lli_rmtperm_time = cfs_time_current();
+	spin_unlock(&lli->lli_lock);
+
+	CDEBUG(D_SEC, "new remote perm@%p: %u/%u/%u/%u - %#x\n",
+	       lrp, lrp->lrp_uid, lrp->lrp_gid, lrp->lrp_fsuid, lrp->lrp_fsgid,
+	       lrp->lrp_access_perm);
+
+	RETURN(0);
+}
+
+int lustre_check_remote_perm(struct inode *inode, int mask)
+{
+	struct ll_inode_info *lli = ll_i2info(inode);
+	struct ll_sb_info *sbi = ll_i2sbi(inode);
+	struct ptlrpc_request *req = NULL;
+	struct mdt_remote_perm *perm;
+	struct obd_capa *oc;
+	cfs_time_t save;
+	int i = 0, rc;
+	ENTRY;
+
+	do {
+		save = lli->lli_rmtperm_time;
+		rc = do_check_remote_perm(lli, mask);
+		if (!rc || (rc != -ENOENT && i))
+			break;
+
+		might_sleep();
+
+		mutex_lock(&lli->lli_rmtperm_mutex);
+		/* check again */
+		if (save != lli->lli_rmtperm_time) {
+			rc = do_check_remote_perm(lli, mask);
+			if (!rc || (rc != -ENOENT && i)) {
+				mutex_unlock(&lli->lli_rmtperm_mutex);
+				break;
+			}
+		}
+
+		if (i++ > 5) {
+			CERROR("check remote perm falls in dead loop!\n");
+			LBUG();
+		}
+
+		oc = ll_mdscapa_get(inode);
+		rc = md_get_remote_perm(sbi->ll_md_exp, ll_inode2fid(inode), oc,
+					ll_i2suppgid(inode), &req);
+		capa_put(oc);
+		if (rc) {
+			mutex_unlock(&lli->lli_rmtperm_mutex);
+			break;
+		}
+
+		perm = req_capsule_server_swab_get(&req->rq_pill, &RMF_ACL,
+						   lustre_swab_mdt_remote_perm);
+		if (unlikely(perm == NULL)) {
+			mutex_unlock(&lli->lli_rmtperm_mutex);
+			rc = -EPROTO;
+			break;
+		}
+
+		rc = ll_update_remote_perm(inode, perm);
+		mutex_unlock(&lli->lli_rmtperm_mutex);
+		if (rc == -ENOMEM)
+			break;
+
+		ptlrpc_req_finished(req);
+		req = NULL;
+	} while (1);
+	ptlrpc_req_finished(req);
+	RETURN(rc);
+}
+
+#if 0  /* NB: remote perms can't be freed in ll_mdc_blocking_ast of UPDATE lock,
+	* because it will fail sanity test 48.
+	*/
+void ll_free_remote_perms(struct inode *inode)
+{
+	struct ll_inode_info *lli = ll_i2info(inode);
+	struct hlist_head *hash = lli->lli_remote_perms;
+	struct ll_remote_perm *lrp;
+	struct hlist_node *node, *next;
+	int i;
+
+	LASSERT(hash);
+
+	spin_lock(&lli->lli_lock);
+
+	for (i = 0; i < REMOTE_PERM_HASHSIZE; i++) {
+		hlist_for_each_entry_safe(lrp, node, next, hash + i,
+					      lrp_list)
+			free_ll_remote_perm(lrp);
+	}
+
+	spin_unlock(&lli->lli_lock);
+}
+#endif