1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
30 * Use is subject to license terms.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * glimpse code shared between vvp and liblustre (and other Lustre clients in
39 * Author: Nikita Danilov <nikita.danilov@sun.com>
40 * Author: Oleg Drokin <oleg.drokin@sun.com>
43 #include <libcfs/libcfs.h>
44 #include <obd_class.h>
45 #include <obd_support.h>
49 # include <lustre_dlm.h>
50 # include <lustre_lite.h>
51 # include <lustre_mdc.h>
52 # include <linux/pagemap.h>
53 # include <linux/file.h>
59 #include <sys/types.h>
61 #include <sys/queue.h>
73 # include <liblustre.h>
76 #include "cl_object.h"
79 # include "../llite/llite_internal.h"
81 # include "../liblustre/llite_lib.h"
84 static const struct cl_lock_descr whole_file = {
86 .cld_end = CL_PAGE_EOF,
90 int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
91 struct inode *inode, struct cl_object *clob)
93 struct cl_lock_descr *descr = &ccc_env_info(env)->cti_descr;
94 struct cl_inode_info *lli = cl_i2info(inode);
95 const struct lu_fid *fid = lu_object_fid(&clob->co_lu);
96 struct ccc_io *cio = ccc_env_io(env);
102 if (!(lli->lli_flags & LLIF_MDS_SIZE_LOCK)) {
103 CDEBUG(D_DLMTRACE, "Glimpsing inode "DFID"\n", PFID(fid));
105 /* NOTE: this looks like DLM lock request, but it may
106 * not be one. Due to CEF_ASYNC flag (translated
107 * to LDLM_FL_HAS_INTENT by osc), this is
108 * glimpse request, that won't revoke any
109 * conflicting DLM locks held. Instead,
110 * ll_glimpse_callback() will be called on each
111 * client holding a DLM lock against this file,
112 * and resulting size will be returned for each
113 * stripe. DLM lock on [0, EOF] is acquired only
114 * if there were no conflicting locks. If there
115 * were conflicting locks, enqueuing or waiting
116 * fails with -ENAVAIL, but valid inode
117 * attributes are returned anyway. */
119 descr->cld_obj = clob;
120 descr->cld_mode = CLM_PHANTOM;
121 descr->cld_enq_flags = CEF_ASYNC | CEF_MUST;
122 cio->cui_glimpse = 1;
124 * CEF_ASYNC is used because glimpse sub-locks cannot
125 * deadlock (because they never conflict with other
126 * locks) and, hence, can be enqueued out-of-order.
128 * CEF_MUST protects glimpse lock from conversion into
131 lock = cl_lock_request(env, io, descr, "glimpse",
133 cio->cui_glimpse = 0;
135 result = cl_wait(env, lock);
140 cl_lock_release(env, lock,
141 "glimpse", cfs_current());
143 result = PTR_ERR(lock);
145 CDEBUG(D_DLMTRACE, "No objects for inode\n");
151 static int cl_io_get(struct inode *inode, struct lu_env **envout,
152 struct cl_io **ioout, int *refcheck)
154 struct ccc_thread_info *info;
157 struct cl_inode_info *lli = cl_i2info(inode);
158 struct cl_object *clob = lli->lli_clob;
161 if (S_ISREG(cl_inode_mode(inode))) {
162 env = cl_env_get(refcheck);
164 info = ccc_env_info(env);
171 result = PTR_ERR(env);
177 int cl_glimpse_size(struct inode *inode)
180 * We don't need ast_flags argument to cl_glimpse_size(), because
181 * osc_lock_enqueue() takes care of the possible deadlock that said
182 * argument was introduced to avoid.
185 * XXX but note that ll_file_seek() passes LDLM_FL_BLOCK_NOWAIT to
186 * cl_glimpse_size(), which doesn't make sense: glimpse locks are not
196 result = cl_io_get(inode, &env, &io, &refcheck);
198 result = cl_io_init(env, io, CIT_MISC, io->ci_obj);
201 * nothing to do for this io. This currently happens
202 * when stripe sub-object's are not yet created.
204 result = io->ci_result;
205 else if (result == 0)
206 result = cl_glimpse_lock(env, io, inode, io->ci_obj);
208 cl_env_put(env, &refcheck);
213 int cl_local_size(struct inode *inode)
217 struct ccc_thread_info *cti;
218 struct cl_object *clob;
219 struct cl_lock_descr *descr;
220 struct cl_lock *lock;
227 * XXX layering violation.
229 if (cl_i2info(inode)->lli_smd->lsm_stripe_count == 0)
232 result = cl_io_get(inode, &env, &io, &refcheck);
237 result = cl_io_init(env, io, CIT_MISC, clob);
239 result = io->ci_result;
240 else if (result == 0) {
241 cti = ccc_env_info(env);
242 descr = &cti->cti_descr;
245 descr->cld_obj = clob;
246 lock = cl_lock_peek(env, io, descr, "localsize", cfs_current());
250 cl_lock_release(env, lock, "localsize", cfs_current());
256 cl_env_put(env, &refcheck);