1 // SPDX-License-Identifier: GPL-2.0
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 only,
9 * as published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License version 2 for more details (a copy is included
15 * in the LICENSE file that accompanied this code).
17 * You should have received a copy of the GNU General Public License
18 * version 2 along with this program; If not, see
19 * http://www.gnu.org/licenses/gpl-2.0.html
24 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
25 * Use is subject to license terms.
27 * Copyright (c) 2011, 2012, Intel Corporation.
30 * This file is part of Lustre, http://www.lustre.org/
31 * Lustre is a trademark of Sun Microsystems, Inc.
33 * glimpse code shared between vvp and liblustre (and other Lustre clients in
36 * Author: Nikita Danilov <nikita.danilov@sun.com>
37 * Author: Oleg Drokin <oleg.drokin@sun.com>
40 #include <linux/libcfs/libcfs.h>
41 #include <obd_class.h>
42 #include <obd_support.h>
45 #include <lustre_dlm.h>
46 #include <lustre_mdc.h>
47 #include <linux/pagemap.h>
48 #include <linux/file.h>
50 #include <cl_object.h>
51 #include "llite_internal.h"
53 static const struct cl_lock_descr whole_file = {
55 .cld_end = CL_PAGE_EOF,
60 * Check whether file has possible unwriten pages.
62 * \retval 1 file is mmap-ed or has dirty pages
65 blkcnt_t dirty_cnt(struct inode *inode)
68 struct vvp_object *vob = cl_inode2vvp(inode);
72 cnt += radix_tree_gang_lookup_tag(&inode->i_mapping->page_tree,
75 if (cnt == 0 && atomic_read(&vob->vob_mmap_cnt) > 0)
78 return (cnt > 0) ? 1 : 0;
81 int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
82 struct inode *inode, struct cl_object *clob, int agl)
84 const struct lu_fid *fid = lu_object_fid(&clob->co_lu);
85 struct cl_lock *lock = vvp_env_lock(env);
86 struct cl_lock_descr *descr = &lock->cll_descr;
89 CDEBUG(D_DLMTRACE, "Glimpsing inode " DFID "\n", PFID(fid));
91 /* NOTE: this looks like DLM lock request, but it may
92 * not be one. Due to CEF_ASYNC flag (translated
93 * to LDLM_FL_HAS_INTENT by osc), this is
94 * glimpse request, that won't revoke any
95 * conflicting DLM locks held. Instead,
96 * ll_glimpse_callback() will be called on each
97 * client holding a DLM lock against this file,
98 * and resulting size will be returned for each
99 * stripe. DLM lock on [0, EOF] is acquired only
100 * if there were no conflicting locks. If there
101 * were conflicting locks, enqueuing or waiting
102 * fails with -ENAVAIL, but valid inode
103 * attributes are returned anyway.
106 descr->cld_obj = clob;
107 descr->cld_mode = CLM_READ;
108 descr->cld_enq_flags = CEF_ASYNC | CEF_MUST;
110 descr->cld_enq_flags |= CEF_AGL;
112 * CEF_ASYNC is used because glimpse sub-locks cannot
113 * deadlock (because they never conflict with other
114 * locks) and, hence, can be enqueued out-of-order.
116 * CEF_MUST protects glimpse lock from conversion into
119 result = cl_lock_request(env, io, lock);
124 ll_merge_attr(env, inode);
125 if (i_size_read(inode) > 0 && !inode->i_blocks) {
127 * LU-417: Add dirty pages block count
128 * lest i_blocks reports 0, some "cp" or
129 * "tar" may think it's a completely
130 * sparse file and skip it.
132 inode->i_blocks = dirty_cnt(inode);
136 cl_lock_release(env, lock);
141 static int cl_io_get(struct inode *inode, struct lu_env **envout,
142 struct cl_io **ioout, u16 *refcheck)
146 struct ll_inode_info *lli = ll_i2info(inode);
147 struct cl_object *clob = lli->lli_clob;
150 if (S_ISREG(inode->i_mode)) {
151 env = cl_env_get(refcheck);
153 io = vvp_env_thread_io(env);
159 result = PTR_ERR(env);
167 int cl_glimpse_size0(struct inode *inode, int agl)
170 * We don't need ast_flags argument to cl_glimpse_size(), because
171 * osc_lock_enqueue() takes care of the possible deadlock that said
172 * argument was introduced to avoid.
175 * XXX but note that ll_file_seek() passes LDLM_FL_BLOCK_NOWAIT to
176 * cl_glimpse_size(), which doesn't make sense: glimpse locks are not
179 struct lu_env *env = NULL;
180 struct cl_io *io = NULL;
184 result = cl_io_get(inode, &env, &io, &refcheck);
187 io->ci_verify_layout = 1;
188 result = cl_io_init(env, io, CIT_MISC, io->ci_obj);
191 * nothing to do for this io. This currently happens
192 * when stripe sub-object's are not yet created.
194 result = io->ci_result;
195 else if (result == 0)
196 result = cl_glimpse_lock(env, io, inode, io->ci_obj,
199 OBD_FAIL_TIMEOUT(OBD_FAIL_GLIMPSE_DELAY, 2);
201 if (unlikely(io->ci_need_restart))
203 cl_env_put(env, &refcheck);