1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
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.
9 *
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).
15 *
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.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2011, 2012, Intel Corporation.
31 */
32 /*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * glimpse code shared between vvp and liblustre (and other Lustre clients in
37 * the future).
38 *
39 * Author: Nikita Danilov <nikita.danilov@sun.com>
40 * Author: Oleg Drokin <oleg.drokin@sun.com>
41 */
42
43 #include "../../include/linux/libcfs/libcfs.h"
44 #include "../include/obd_class.h"
45 #include "../include/obd_support.h"
46 #include "../include/obd.h"
47
48 #include "../include/lustre_dlm.h"
49 #include "../include/lustre_lite.h"
50 #include "../include/lustre_mdc.h"
51 #include <linux/pagemap.h>
52 #include <linux/file.h>
53
54 #include "../include/cl_object.h"
55 #include "../include/lclient.h"
56 #include "../llite/llite_internal.h"
57
58 static const struct cl_lock_descr whole_file = {
59 .cld_start = 0,
60 .cld_end = CL_PAGE_EOF,
61 .cld_mode = CLM_READ
62 };
63
64 /*
65 * Check whether file has possible unwriten pages.
66 *
67 * \retval 1 file is mmap-ed or has dirty pages
68 * 0 otherwise
69 */
dirty_cnt(struct inode * inode)70 blkcnt_t dirty_cnt(struct inode *inode)
71 {
72 blkcnt_t cnt = 0;
73 struct ccc_object *vob = cl_inode2ccc(inode);
74 void *results[1];
75
76 if (inode->i_mapping)
77 cnt += radix_tree_gang_lookup_tag(&inode->i_mapping->page_tree,
78 results, 0, 1,
79 PAGECACHE_TAG_DIRTY);
80 if (cnt == 0 && atomic_read(&vob->cob_mmap_cnt) > 0)
81 cnt = 1;
82
83 return (cnt > 0) ? 1 : 0;
84 }
85
cl_glimpse_lock(const struct lu_env * env,struct cl_io * io,struct inode * inode,struct cl_object * clob,int agl)86 int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
87 struct inode *inode, struct cl_object *clob, int agl)
88 {
89 struct cl_lock_descr *descr = &ccc_env_info(env)->cti_descr;
90 struct cl_inode_info *lli = cl_i2info(inode);
91 const struct lu_fid *fid = lu_object_fid(&clob->co_lu);
92 struct ccc_io *cio = ccc_env_io(env);
93 struct cl_lock *lock;
94 int result;
95
96 result = 0;
97 if (!(lli->lli_flags & LLIF_MDS_SIZE_LOCK)) {
98 CDEBUG(D_DLMTRACE, "Glimpsing inode "DFID"\n", PFID(fid));
99 if (lli->lli_has_smd) {
100 /* NOTE: this looks like DLM lock request, but it may
101 * not be one. Due to CEF_ASYNC flag (translated
102 * to LDLM_FL_HAS_INTENT by osc), this is
103 * glimpse request, that won't revoke any
104 * conflicting DLM locks held. Instead,
105 * ll_glimpse_callback() will be called on each
106 * client holding a DLM lock against this file,
107 * and resulting size will be returned for each
108 * stripe. DLM lock on [0, EOF] is acquired only
109 * if there were no conflicting locks. If there
110 * were conflicting locks, enqueuing or waiting
111 * fails with -ENAVAIL, but valid inode
112 * attributes are returned anyway. */
113 *descr = whole_file;
114 descr->cld_obj = clob;
115 descr->cld_mode = CLM_PHANTOM;
116 descr->cld_enq_flags = CEF_ASYNC | CEF_MUST;
117 if (agl)
118 descr->cld_enq_flags |= CEF_AGL;
119 cio->cui_glimpse = 1;
120 /*
121 * CEF_ASYNC is used because glimpse sub-locks cannot
122 * deadlock (because they never conflict with other
123 * locks) and, hence, can be enqueued out-of-order.
124 *
125 * CEF_MUST protects glimpse lock from conversion into
126 * a lockless mode.
127 */
128 lock = cl_lock_request(env, io, descr, "glimpse",
129 current);
130 cio->cui_glimpse = 0;
131
132 if (!lock)
133 return 0;
134
135 if (IS_ERR(lock))
136 return PTR_ERR(lock);
137
138 LASSERT(agl == 0);
139 result = cl_wait(env, lock);
140 if (result == 0) {
141 cl_merge_lvb(env, inode);
142 if (cl_isize_read(inode) > 0 &&
143 inode->i_blocks == 0) {
144 /*
145 * LU-417: Add dirty pages block count
146 * lest i_blocks reports 0, some "cp" or
147 * "tar" may think it's a completely
148 * sparse file and skip it.
149 */
150 inode->i_blocks = dirty_cnt(inode);
151 }
152 cl_unuse(env, lock);
153 }
154 cl_lock_release(env, lock, "glimpse", current);
155 } else {
156 CDEBUG(D_DLMTRACE, "No objects for inode\n");
157 cl_merge_lvb(env, inode);
158 }
159 }
160
161 return result;
162 }
163
cl_io_get(struct inode * inode,struct lu_env ** envout,struct cl_io ** ioout,int * refcheck)164 static int cl_io_get(struct inode *inode, struct lu_env **envout,
165 struct cl_io **ioout, int *refcheck)
166 {
167 struct lu_env *env;
168 struct cl_io *io;
169 struct cl_inode_info *lli = cl_i2info(inode);
170 struct cl_object *clob = lli->lli_clob;
171 int result;
172
173 if (S_ISREG(cl_inode_mode(inode))) {
174 env = cl_env_get(refcheck);
175 if (!IS_ERR(env)) {
176 io = ccc_env_thread_io(env);
177 io->ci_obj = clob;
178 *envout = env;
179 *ioout = io;
180 result = 1;
181 } else
182 result = PTR_ERR(env);
183 } else
184 result = 0;
185 return result;
186 }
187
cl_glimpse_size0(struct inode * inode,int agl)188 int cl_glimpse_size0(struct inode *inode, int agl)
189 {
190 /*
191 * We don't need ast_flags argument to cl_glimpse_size(), because
192 * osc_lock_enqueue() takes care of the possible deadlock that said
193 * argument was introduced to avoid.
194 */
195 /*
196 * XXX but note that ll_file_seek() passes LDLM_FL_BLOCK_NOWAIT to
197 * cl_glimpse_size(), which doesn't make sense: glimpse locks are not
198 * blocking anyway.
199 */
200 struct lu_env *env = NULL;
201 struct cl_io *io = NULL;
202 int result;
203 int refcheck;
204
205 result = cl_io_get(inode, &env, &io, &refcheck);
206 if (result > 0) {
207 again:
208 io->ci_verify_layout = 1;
209 result = cl_io_init(env, io, CIT_MISC, io->ci_obj);
210 if (result > 0)
211 /*
212 * nothing to do for this io. This currently happens
213 * when stripe sub-object's are not yet created.
214 */
215 result = io->ci_result;
216 else if (result == 0)
217 result = cl_glimpse_lock(env, io, inode, io->ci_obj,
218 agl);
219
220 OBD_FAIL_TIMEOUT(OBD_FAIL_GLIMPSE_DELAY, 2);
221 cl_io_fini(env, io);
222 if (unlikely(io->ci_need_restart))
223 goto again;
224 cl_env_put(env, &refcheck);
225 }
226 return result;
227 }
228
cl_local_size(struct inode * inode)229 int cl_local_size(struct inode *inode)
230 {
231 struct lu_env *env = NULL;
232 struct cl_io *io = NULL;
233 struct ccc_thread_info *cti;
234 struct cl_object *clob;
235 struct cl_lock_descr *descr;
236 struct cl_lock *lock;
237 int result;
238 int refcheck;
239
240 if (!cl_i2info(inode)->lli_has_smd)
241 return 0;
242
243 result = cl_io_get(inode, &env, &io, &refcheck);
244 if (result <= 0)
245 return result;
246
247 clob = io->ci_obj;
248 result = cl_io_init(env, io, CIT_MISC, clob);
249 if (result > 0)
250 result = io->ci_result;
251 else if (result == 0) {
252 cti = ccc_env_info(env);
253 descr = &cti->cti_descr;
254
255 *descr = whole_file;
256 descr->cld_obj = clob;
257 lock = cl_lock_peek(env, io, descr, "localsize", current);
258 if (lock) {
259 cl_merge_lvb(env, inode);
260 cl_unuse(env, lock);
261 cl_lock_release(env, lock, "localsize", current);
262 result = 0;
263 } else
264 result = -ENODATA;
265 }
266 cl_io_fini(env, io);
267 cl_env_put(env, &refcheck);
268 return result;
269 }
270