Whamcloud - gitweb
dca7a3926ad50833da5f43f7f6ea569a1ca19428
[fs/lustre-release.git] / lustre / llite / vvp_dev.c
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) 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  * cl_device and cl_device_type implementation for VVP layer.
37  *
38  *   Author: Nikita Danilov <nikita.danilov@sun.com>
39  */
40
41 #define DEBUG_SUBSYSTEM S_LLITE
42
43 #ifndef __KERNEL__
44 # error This file is kernel only.
45 #endif
46
47 #include <obd.h>
48 #include <lustre_lite.h>
49
50 #include "vvp_internal.h"
51
52 /*****************************************************************************
53  *
54  * Vvp device and device type functions.
55  *
56  */
57
58 /*
59  * vvp_ prefix stands for "Vfs Vm Posix". It corresponds to historical
60  * "llite_" (var. "ll_") prefix.
61  */
62
63 cfs_mem_cache_t *vvp_page_kmem;
64 cfs_mem_cache_t *vvp_thread_kmem;
65 static cfs_mem_cache_t *vvp_session_kmem;
66 static struct lu_kmem_descr vvp_caches[] = {
67         {
68                 .ckd_cache = &vvp_page_kmem,
69                 .ckd_name  = "vvp_page_kmem",
70                 .ckd_size  = sizeof (struct ccc_page)
71         },
72         {
73                 .ckd_cache = &vvp_thread_kmem,
74                 .ckd_name  = "vvp_thread_kmem",
75                 .ckd_size  = sizeof (struct vvp_thread_info),
76         },
77         {
78                 .ckd_cache = &vvp_session_kmem,
79                 .ckd_name  = "vvp_session_kmem",
80                 .ckd_size  = sizeof (struct vvp_session)
81         },
82         {
83                 .ckd_cache = NULL
84         }
85 };
86
87 static void *vvp_key_init(const struct lu_context *ctx,
88                           struct lu_context_key *key)
89 {
90         struct vvp_thread_info *info;
91
92         OBD_SLAB_ALLOC_PTR_GFP(info, vvp_thread_kmem, CFS_ALLOC_IO);
93         if (info == NULL)
94                 info = ERR_PTR(-ENOMEM);
95         return info;
96 }
97
98 static void vvp_key_fini(const struct lu_context *ctx,
99                          struct lu_context_key *key, void *data)
100 {
101         struct vvp_thread_info *info = data;
102         OBD_SLAB_FREE_PTR(info, vvp_thread_kmem);
103 }
104
105 static void *vvp_session_key_init(const struct lu_context *ctx,
106                                   struct lu_context_key *key)
107 {
108         struct vvp_session *session;
109
110         OBD_SLAB_ALLOC_PTR_GFP(session, vvp_session_kmem, CFS_ALLOC_IO);
111         if (session == NULL)
112                 session = ERR_PTR(-ENOMEM);
113         return session;
114 }
115
116 static void vvp_session_key_fini(const struct lu_context *ctx,
117                                  struct lu_context_key *key, void *data)
118 {
119         struct vvp_session *session = data;
120         OBD_SLAB_FREE_PTR(session, vvp_session_kmem);
121 }
122
123
124 struct lu_context_key vvp_key = {
125         .lct_tags = LCT_CL_THREAD,
126         .lct_init = vvp_key_init,
127         .lct_fini = vvp_key_fini
128 };
129
130 struct lu_context_key vvp_session_key = {
131         .lct_tags = LCT_SESSION,
132         .lct_init = vvp_session_key_init,
133         .lct_fini = vvp_session_key_fini
134 };
135
136 /* type constructor/destructor: vvp_type_{init,fini,start,stop}(). */
137 LU_TYPE_INIT_FINI(vvp, &ccc_key, &ccc_session_key, &vvp_key, &vvp_session_key);
138
139 static const struct lu_device_operations vvp_lu_ops = {
140         .ldo_object_alloc      = vvp_object_alloc
141 };
142
143 static const struct cl_device_operations vvp_cl_ops = {
144         .cdo_req_init = ccc_req_init
145 };
146
147 static struct lu_device *vvp_device_alloc(const struct lu_env *env,
148                                           struct lu_device_type *t,
149                                           struct lustre_cfg *cfg)
150 {
151         return ccc_device_alloc(env, t, cfg, &vvp_lu_ops, &vvp_cl_ops);
152 }
153
154 static const struct lu_device_type_operations vvp_device_type_ops = {
155         .ldto_init = vvp_type_init,
156         .ldto_fini = vvp_type_fini,
157
158         .ldto_start = vvp_type_start,
159         .ldto_stop  = vvp_type_stop,
160
161         .ldto_device_alloc = vvp_device_alloc,
162         .ldto_device_free  = ccc_device_free,
163         .ldto_device_init  = ccc_device_init,
164         .ldto_device_fini  = ccc_device_fini
165 };
166
167 struct lu_device_type vvp_device_type = {
168         .ldt_tags     = LU_DEVICE_CL,
169         .ldt_name     = LUSTRE_VVP_NAME,
170         .ldt_ops      = &vvp_device_type_ops,
171         .ldt_ctx_tags = LCT_CL_THREAD
172 };
173
174 /**
175  * A mutex serializing calls to vvp_inode_fini() under extreme memory
176  * pressure, when environments cannot be allocated.
177  */
178 int vvp_global_init(void)
179 {
180         int result;
181
182         result = lu_kmem_init(vvp_caches);
183         if (result == 0) {
184                 result = ccc_global_init(&vvp_device_type);
185                 if (result != 0)
186                         lu_kmem_fini(vvp_caches);
187         }
188         return result;
189 }
190
191 void vvp_global_fini(void)
192 {
193         ccc_global_fini(&vvp_device_type);
194         lu_kmem_fini(vvp_caches);
195 }
196
197
198 /*****************************************************************************
199  *
200  * mirror obd-devices into cl devices.
201  *
202  */
203
204 int cl_sb_init(struct super_block *sb)
205 {
206         struct ll_sb_info *sbi;
207         struct cl_device  *cl;
208         struct lu_env     *env;
209         int rc = 0;
210         int refcheck;
211
212         sbi  = ll_s2sbi(sb);
213         env = cl_env_get(&refcheck);
214         if (!IS_ERR(env)) {
215                 cl = cl_type_setup(env, NULL, &vvp_device_type,
216                                    sbi->ll_dt_exp->exp_obd->obd_lu_dev);
217                 if (!IS_ERR(cl)) {
218                         cl2ccc_dev(cl)->cdv_sb = sb;
219                         sbi->ll_cl = cl;
220                         sbi->ll_site = cl2lu_dev(cl)->ld_site;
221                 }
222                 cl_env_put(env, &refcheck);
223         } else
224                 rc = PTR_ERR(env);
225         RETURN(rc);
226 }
227
228 int cl_sb_fini(struct super_block *sb)
229 {
230         struct ll_sb_info *sbi;
231         struct lu_env     *env;
232         struct cl_device  *cld;
233         int                refcheck;
234         int                result;
235
236         ENTRY;
237         sbi = ll_s2sbi(sb);
238         env = cl_env_get(&refcheck);
239         if (!IS_ERR(env)) {
240                 cld = sbi->ll_cl;
241
242                 if (cld != NULL) {
243                         cl_stack_fini(env, cld);
244                         sbi->ll_cl = NULL;
245                         sbi->ll_site = NULL;
246                 }
247                 cl_env_put(env, &refcheck);
248                 result = 0;
249         } else {
250                 CERROR("Cannot cleanup cl-stack due to memory shortage.\n");
251                 result = PTR_ERR(env);
252         }
253         /*
254          * If mount failed (sbi->ll_cl == NULL), and this there are no other
255          * mounts, stop device types manually (this usually happens
256          * automatically when last device is destroyed).
257          */
258         lu_types_stop();
259         RETURN(result);
260 }
261
262 /****************************************************************************
263  *
264  * /proc/fs/lustre/llite/$MNT/dump_page_cache
265  *
266  ****************************************************************************/
267
268 /*
269  * To represent contents of a page cache as a byte stream, following
270  * information if encoded in 64bit offset:
271  *
272  *       - file hash bucket in lu_site::ls_hash[]       28bits
273  *
274  *       - how far file is from bucket head              4bits
275  *
276  *       - page index                                   32bits
277  *
278  * First two data identify a file in the cache uniquely.
279  */
280
281 #define PGC_OBJ_SHIFT (32 + 4)
282 #define PGC_DEPTH_SHIFT (32)
283
284 struct vvp_pgcache_id {
285         unsigned                 vpi_bucket;
286         unsigned                 vpi_depth;
287         uint32_t                 vpi_index;
288
289         unsigned                 vpi_curdep;
290         struct lu_object_header *vpi_obj;
291 };
292
293 static void vvp_pgcache_id_unpack(loff_t pos, struct vvp_pgcache_id *id)
294 {
295         CLASSERT(sizeof(pos) == sizeof(__u64));
296
297         id->vpi_index  = pos & 0xffffffff;
298         id->vpi_depth  = (pos >> PGC_DEPTH_SHIFT) & 0xf;
299         id->vpi_bucket = ((unsigned long long)pos >> PGC_OBJ_SHIFT);
300 }
301
302 static loff_t vvp_pgcache_id_pack(struct vvp_pgcache_id *id)
303 {
304         return
305                 ((__u64)id->vpi_index) |
306                 ((__u64)id->vpi_depth  << PGC_DEPTH_SHIFT) |
307                 ((__u64)id->vpi_bucket << PGC_OBJ_SHIFT);
308 }
309
310 static int vvp_pgcache_obj_get(cfs_hash_t *hs, cfs_hash_bd_t *bd,
311                                cfs_hlist_node_t *hnode, void *data)
312 {
313         struct vvp_pgcache_id   *id  = data;
314         struct lu_object_header *hdr = cfs_hash_object(hs, hnode);
315
316         if (id->vpi_curdep-- > 0)
317                 return 0; /* continue */
318
319         if (lu_object_is_dying(hdr))
320                 return 1;
321
322         cfs_hash_get(hs, hnode);
323         id->vpi_obj = hdr;
324         return 1;
325 }
326
327 static struct cl_object *vvp_pgcache_obj(const struct lu_env *env,
328                                          struct lu_device *dev,
329                                          struct vvp_pgcache_id *id)
330 {
331         LASSERT(lu_device_is_cl(dev));
332
333         id->vpi_depth &= 0xf;
334         id->vpi_obj    = NULL;
335         id->vpi_curdep = id->vpi_depth;
336
337         cfs_hash_hlist_for_each(dev->ld_site->ls_obj_hash, id->vpi_bucket,
338                                 vvp_pgcache_obj_get, id);
339         if (id->vpi_obj != NULL) {
340                 struct lu_object *lu_obj;
341
342                 lu_obj = lu_object_locate(id->vpi_obj, dev->ld_type);
343                 if (lu_obj != NULL) {
344                         lu_object_ref_add(lu_obj, "dump", cfs_current());
345                         return lu2cl(lu_obj);
346                 }
347                 lu_object_put(env, lu_object_top(id->vpi_obj));
348
349         } else if (id->vpi_curdep > 0) {
350                 id->vpi_depth = 0xf;
351         }
352         return NULL;
353 }
354
355 static loff_t vvp_pgcache_find(const struct lu_env *env,
356                                struct lu_device *dev, loff_t pos)
357 {
358         struct cl_object     *clob;
359         struct lu_site       *site;
360         struct vvp_pgcache_id id;
361
362         site = dev->ld_site;
363         vvp_pgcache_id_unpack(pos, &id);
364
365         while (1) {
366                 if (id.vpi_bucket >= CFS_HASH_NHLIST(site->ls_obj_hash))
367                         return ~0ULL;
368                 clob = vvp_pgcache_obj(env, dev, &id);
369                 if (clob != NULL) {
370                         struct cl_object_header *hdr;
371                         int                      nr;
372                         struct cl_page          *pg;
373
374                         /* got an object. Find next page. */
375                         hdr = cl_object_header(clob);
376
377                         spin_lock(&hdr->coh_page_guard);
378                         nr = radix_tree_gang_lookup(&hdr->coh_tree,
379                                                     (void **)&pg,
380                                                     id.vpi_index, 1);
381                         if (nr > 0) {
382                                 id.vpi_index = pg->cp_index;
383                                 /* Cant support over 16T file */
384                                 nr = !(pg->cp_index > 0xffffffff);
385                         }
386                         spin_unlock(&hdr->coh_page_guard);
387
388                         lu_object_ref_del(&clob->co_lu, "dump", cfs_current());
389                         cl_object_put(env, clob);
390                         if (nr > 0)
391                                 return vvp_pgcache_id_pack(&id);
392                 }
393                 /* to the next object. */
394                 ++id.vpi_depth;
395                 id.vpi_depth &= 0xf;
396                 if (id.vpi_depth == 0 && ++id.vpi_bucket == 0)
397                         return ~0ULL;
398                 id.vpi_index = 0;
399         }
400 }
401
402 #define seq_page_flag(seq, page, flag, has_flags) do {                  \
403         if (test_bit(PG_##flag, &(page)->flags)) {                  \
404                 seq_printf(seq, "%s"#flag, has_flags ? "|" : "");       \
405                 has_flags = 1;                                          \
406         }                                                               \
407 } while(0)
408
409 static void vvp_pgcache_page_show(const struct lu_env *env,
410                                   struct seq_file *seq, struct cl_page *page)
411 {
412         struct ccc_page *cpg;
413         cfs_page_t      *vmpage;
414         int              has_flags;
415
416         cpg = cl2ccc_page(cl_page_at(page, &vvp_device_type));
417         vmpage = cpg->cpg_page;
418         seq_printf(seq," %5i | %p %p %s %s %s %s | %p %lu/%u(%p) %lu %u [",
419                    0 /* gen */,
420                    cpg, page,
421                    "none",
422                    cpg->cpg_write_queued ? "wq" : "- ",
423                    cpg->cpg_defer_uptodate ? "du" : "- ",
424                    PageWriteback(vmpage) ? "wb" : "-",
425                    vmpage, vmpage->mapping->host->i_ino,
426                    vmpage->mapping->host->i_generation,
427                    vmpage->mapping->host, vmpage->index,
428                    page_count(vmpage));
429         has_flags = 0;
430         seq_page_flag(seq, vmpage, locked, has_flags);
431         seq_page_flag(seq, vmpage, error, has_flags);
432         seq_page_flag(seq, vmpage, referenced, has_flags);
433         seq_page_flag(seq, vmpage, uptodate, has_flags);
434         seq_page_flag(seq, vmpage, dirty, has_flags);
435         seq_page_flag(seq, vmpage, writeback, has_flags);
436         seq_printf(seq, "%s]\n", has_flags ? "" : "-");
437 }
438
439 static int vvp_pgcache_show(struct seq_file *f, void *v)
440 {
441         loff_t                   pos;
442         struct ll_sb_info       *sbi;
443         struct cl_object        *clob;
444         struct lu_env           *env;
445         struct cl_page          *page;
446         struct cl_object_header *hdr;
447         struct vvp_pgcache_id    id;
448         int                      refcheck;
449         int                      result;
450
451         env = cl_env_get(&refcheck);
452         if (!IS_ERR(env)) {
453                 pos = *(loff_t *) v;
454                 vvp_pgcache_id_unpack(pos, &id);
455                 sbi = f->private;
456                 clob = vvp_pgcache_obj(env, &sbi->ll_cl->cd_lu_dev, &id);
457                 if (clob != NULL) {
458                         hdr = cl_object_header(clob);
459
460                         spin_lock(&hdr->coh_page_guard);
461                         page = cl_page_lookup(hdr, id.vpi_index);
462                         spin_unlock(&hdr->coh_page_guard);
463
464                         seq_printf(f, "%8x@"DFID": ",
465                                    id.vpi_index, PFID(&hdr->coh_lu.loh_fid));
466                         if (page != NULL) {
467                                 vvp_pgcache_page_show(env, f, page);
468                                 cl_page_put(env, page);
469                         } else
470                                 seq_puts(f, "missing\n");
471                         lu_object_ref_del(&clob->co_lu, "dump", cfs_current());
472                         cl_object_put(env, clob);
473                 } else
474                         seq_printf(f, "%llx missing\n", pos);
475                 cl_env_put(env, &refcheck);
476                 result = 0;
477         } else
478                 result = PTR_ERR(env);
479         return result;
480 }
481
482 static void *vvp_pgcache_start(struct seq_file *f, loff_t *pos)
483 {
484         struct ll_sb_info *sbi;
485         struct lu_env     *env;
486         int                refcheck;
487
488         sbi = f->private;
489
490         env = cl_env_get(&refcheck);
491         if (!IS_ERR(env)) {
492                 sbi = f->private;
493                 if (sbi->ll_site->ls_obj_hash->hs_cur_bits > 64 - PGC_OBJ_SHIFT)
494                         pos = ERR_PTR(-EFBIG);
495                 else {
496                         *pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev,
497                                                 *pos);
498                         if (*pos == ~0ULL)
499                                 pos = NULL;
500                 }
501                 cl_env_put(env, &refcheck);
502         }
503         return pos;
504 }
505
506 static void *vvp_pgcache_next(struct seq_file *f, void *v, loff_t *pos)
507 {
508         struct ll_sb_info *sbi;
509         struct lu_env     *env;
510         int                refcheck;
511
512         env = cl_env_get(&refcheck);
513         if (!IS_ERR(env)) {
514                 sbi = f->private;
515                 *pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev, *pos + 1);
516                 if (*pos == ~0ULL)
517                         pos = NULL;
518                 cl_env_put(env, &refcheck);
519         }
520         return pos;
521 }
522
523 static void vvp_pgcache_stop(struct seq_file *f, void *v)
524 {
525         /* Nothing to do */
526 }
527
528 static struct seq_operations vvp_pgcache_ops = {
529         .start = vvp_pgcache_start,
530         .next  = vvp_pgcache_next,
531         .stop  = vvp_pgcache_stop,
532         .show  = vvp_pgcache_show
533 };
534
535 static int vvp_dump_pgcache_seq_open(struct inode *inode, struct file *filp)
536 {
537         struct proc_dir_entry *dp  = PDE(inode);
538         struct ll_sb_info     *sbi = dp->data;
539         struct seq_file       *seq;
540         int                    result;
541
542         result = seq_open(filp, &vvp_pgcache_ops);
543         if (result == 0) {
544                 seq = filp->private_data;
545                 seq->private = sbi;
546         }
547         return result;
548 }
549
550 struct file_operations vvp_dump_pgcache_file_ops = {
551         .owner   = THIS_MODULE,
552         .open    = vvp_dump_pgcache_seq_open,
553         .read    = seq_read,
554         .llseek  = seq_lseek,
555         .release = seq_release,
556 };