4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2017, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
31 * glimpse code used by vvp (and other Lustre clients in the future).
33 * Author: Nikita Danilov <nikita.danilov@sun.com>
34 * Author: Oleg Drokin <oleg.drokin@sun.com>
37 #include <libcfs/libcfs.h>
38 #include <obd_class.h>
39 #include <obd_support.h>
42 #include <lustre_dlm.h>
43 #include <lustre_mdc.h>
44 #include <linux/pagemap.h>
45 #include <linux/file.h>
47 #include "cl_object.h"
48 #include "llite_internal.h"
49 #include "vvp_internal.h"
51 static const struct cl_lock_descr whole_file = {
53 .cld_end = CL_PAGE_EOF,
58 * Check whether file has possible unwritten pages.
60 * \retval 1 file is mmap-ed or has dirty pages
63 blkcnt_t dirty_cnt(struct inode *inode)
66 struct vvp_object *vob = cl_inode2vvp(inode);
69 if (inode->i_mapping != NULL)
70 cnt += radix_tree_gang_lookup_tag(&inode->i_mapping->page_tree,
73 if (cnt == 0 && atomic_read(&vob->vob_mmap_cnt) > 0)
76 return (cnt > 0) ? 1 : 0;
79 int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
80 struct inode *inode, struct cl_object *clob, int agl)
82 const struct lu_fid *fid = lu_object_fid(&clob->co_lu);
83 struct cl_lock *lock = vvp_env_lock(env);
84 struct cl_lock_descr *descr = &lock->cll_descr;
90 CDEBUG(D_DLMTRACE, "Glimpsing inode "DFID"\n", PFID(fid));
92 /* NOTE: this looks like DLM lock request, but it may
93 * not be one. Due to CEF_GLIMPSE flag (translated
94 * to LDLM_FL_HAS_INTENT by osc), this is
95 * glimpse request, that won't revoke any
96 * conflicting DLM locks held. Instead,
97 * ll_glimpse_callback() will be called on each
98 * client holding a DLM lock against this file,
99 * and resulting size will be returned for each
100 * stripe. DLM lock on [0, EOF] is acquired only
101 * if there were no conflicting locks. If there
102 * were conflicting locks, enqueuing or waiting
103 * fails with -ENAVAIL, but valid inode
104 * attributes are returned anyway.
107 descr->cld_obj = clob;
108 descr->cld_mode = CLM_READ;
109 descr->cld_enq_flags = CEF_GLIMPSE | CEF_MUST;
111 descr->cld_enq_flags |= CEF_SPECULATIVE | CEF_NONBLOCK;
113 * CEF_MUST protects glimpse lock from conversion into
116 result = cl_lock_request(env, io, lock);
121 ll_merge_attr(env, inode);
122 if (i_size_read(inode) > 0 && inode->i_blocks == 0) {
124 * LU-417: Add dirty pages block count
125 * lest i_blocks reports 0, some "cp" or
126 * "tar" may think it's a completely
127 * sparse file and skip it.
129 inode->i_blocks = dirty_cnt(inode);
133 cl_lock_release(env, lock);
139 * Get an IO environment for special operations such as glimpse locks and
140 * manually requested locks (ladvise lockahead)
142 * \param[in] inode inode the operation is being performed on
143 * \param[out] envout thread specific execution environment
144 * \param[out] ioout client io description
145 * \param[out] refcheck reference check
147 * \retval 1 on success
148 * \retval 0 not a regular file, cannot get environment
149 * \retval negative negative errno on error
151 int cl_io_get(struct inode *inode, struct lu_env **envout,
152 struct cl_io **ioout, u16 *refcheck)
156 struct ll_inode_info *lli = ll_i2info(inode);
157 struct cl_object *clob = lli->lli_clob;
160 if (S_ISREG(inode->i_mode)) {
161 env = cl_env_get(refcheck);
163 io = vvp_env_thread_io(env);
169 result = PTR_ERR(env);
177 int cl_glimpse_size0(struct inode *inode, int agl)
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
189 struct lu_env *env = NULL;
190 struct cl_io *io = NULL;
197 result = cl_io_get(inode, &env, &io, &refcheck);
202 io->ci_ndelay_tried = retried++;
203 io->ci_ndelay = io->ci_verify_layout = 1;
204 result = cl_io_init(env, io, CIT_GLIMPSE, io->ci_obj);
207 * nothing to do for this io. This currently happens
208 * when stripe sub-object's are not yet created.
210 result = io->ci_result;
211 } else if (result == 0) {
212 result = cl_glimpse_lock(env, io, inode, io->ci_obj,
215 * need to limit retries for FLR mirrors if fast read
216 * is short because of concurrent truncate.
218 if (!agl && result == -EAGAIN &&
219 !io->ci_tried_all_mirrors)
220 io->ci_need_restart = 1;
223 CFS_FAIL_TIMEOUT(OBD_FAIL_GLIMPSE_DELAY, cfs_fail_val ?: 4);
225 } while (unlikely(io->ci_need_restart));
227 cl_env_put(env, &refcheck);