staging: add Lustre file system client support

Lustre is the most deployed distributed file system
in the HPC (High Performance Computing) world. The patch
adds its client side support.

The code is not very clean and needs to live in drivers/staging
for some time for continuing cleanup work. See
drivers/staging/lustre/TODO for details.

The code is based on Lustre master commit faefbfc04

commit faefbfc0460bc00f2ee4c1c1c86aa1e39b9eea49
Author: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Date:   Tue Apr 30 23:05:21 2013 +0400

    LU-3244 utils: tunefs.lustre should preserve virgin label

Plus a few under-review patches on Whamcloud gerrit:
3.8 kernel support:
http://review.whamcloud.com/#change,5973
http://review.whamcloud.com/#change,5974
http://review.whamcloud.com/#change,5768
http://review.whamcloud.com/#change,5781
http://review.whamcloud.com/#change,5763
http://review.whamcloud.com/#change,5613
http://review.whamcloud.com/#change,5655

3.9 kernel support:
http://review.whamcloud.com/#change,5898
http://review.whamcloud.com/#change,5899

Kconfig/Kbuild:
http://review.whamcloud.com/#change,4646
http://review.whamcloud.com/#change,4644

libcfs cleanup:
http://review.whamcloud.com/#change,2831
http://review.whamcloud.com/#change,4775
http://review.whamcloud.com/#change,4776
http://review.whamcloud.com/#change,4777
http://review.whamcloud.com/#change,4778
http://review.whamcloud.com/#change,4779
http://review.whamcloud.com/#change,4780

All starting/trailing whitespaces are removed, to match kernel
coding style. Also ran scripts/cleanfile on all lustre source files.

[maked the Kconfig depend on BROKEN as the recent procfs changes causes
this to fail - gregkh]

Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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