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[~andy/linux] / drivers / staging / lustre / lustre / lov / lov_object.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) 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  * Implementation of cl_object for LOV layer.
37  *
38  *   Author: Nikita Danilov <nikita.danilov@sun.com>
39  *   Author: Jinshan Xiong <jinshan.xiong@whamcloud.com>
40  */
41
42 #define DEBUG_SUBSYSTEM S_LOV
43
44 #include "lov_cl_internal.h"
45 #include <lustre_debug.h>
46
47 /** \addtogroup lov
48  *  @{
49  */
50
51 /*****************************************************************************
52  *
53  * Layout operations.
54  *
55  */
56
57 struct lov_layout_operations {
58         int (*llo_init)(const struct lu_env *env, struct lov_device *dev,
59                         struct lov_object *lov,
60                         const struct cl_object_conf *conf,
61                         union lov_layout_state *state);
62         int (*llo_delete)(const struct lu_env *env, struct lov_object *lov,
63                            union lov_layout_state *state);
64         void (*llo_fini)(const struct lu_env *env, struct lov_object *lov,
65                          union lov_layout_state *state);
66         void (*llo_install)(const struct lu_env *env, struct lov_object *lov,
67                             union lov_layout_state *state);
68         int  (*llo_print)(const struct lu_env *env, void *cookie,
69                           lu_printer_t p, const struct lu_object *o);
70         int  (*llo_page_init)(const struct lu_env *env, struct cl_object *obj,
71                                 struct cl_page *page, struct page *vmpage);
72         int  (*llo_lock_init)(const struct lu_env *env,
73                               struct cl_object *obj, struct cl_lock *lock,
74                               const struct cl_io *io);
75         int  (*llo_io_init)(const struct lu_env *env,
76                             struct cl_object *obj, struct cl_io *io);
77         int  (*llo_getattr)(const struct lu_env *env, struct cl_object *obj,
78                             struct cl_attr *attr);
79 };
80
81 static int lov_layout_wait(const struct lu_env *env, struct lov_object *lov);
82
83 /*****************************************************************************
84  *
85  * Lov object layout operations.
86  *
87  */
88
89 static void lov_install_empty(const struct lu_env *env,
90                               struct lov_object *lov,
91                               union  lov_layout_state *state)
92 {
93         /*
94          * File without objects.
95          */
96 }
97
98 static int lov_init_empty(const struct lu_env *env,
99                           struct lov_device *dev, struct lov_object *lov,
100                           const struct cl_object_conf *conf,
101                           union  lov_layout_state *state)
102 {
103         return 0;
104 }
105
106 static void lov_install_raid0(const struct lu_env *env,
107                               struct lov_object *lov,
108                               union  lov_layout_state *state)
109 {
110 }
111
112 static struct cl_object *lov_sub_find(const struct lu_env *env,
113                                       struct cl_device *dev,
114                                       const struct lu_fid *fid,
115                                       const struct cl_object_conf *conf)
116 {
117         struct lu_object *o;
118
119         o = lu_object_find_at(env, cl2lu_dev(dev), fid, &conf->coc_lu);
120         LASSERT(ergo(!IS_ERR(o), o->lo_dev->ld_type == &lovsub_device_type));
121         return lu2cl(o);
122 }
123
124 static int lov_init_sub(const struct lu_env *env, struct lov_object *lov,
125                         struct cl_object *stripe,
126                         struct lov_layout_raid0 *r0, int idx)
127 {
128         struct cl_object_header *hdr;
129         struct cl_object_header *subhdr;
130         struct cl_object_header *parent;
131         struct lov_oinfo        *oinfo;
132         int result;
133
134         if (OBD_FAIL_CHECK(OBD_FAIL_LOV_INIT)) {
135                 /* For sanity:test_206.
136                  * Do not leave the object in cache to avoid accessing
137                  * freed memory. This is because osc_object is referring to
138                  * lov_oinfo of lsm_stripe_data which will be freed due to
139                  * this failure. */
140                 cl_object_kill(env, stripe);
141                 cl_object_put(env, stripe);
142                 return -EIO;
143         }
144
145         hdr    = cl_object_header(lov2cl(lov));
146         subhdr = cl_object_header(stripe);
147         parent = subhdr->coh_parent;
148
149         oinfo = lov->lo_lsm->lsm_oinfo[idx];
150         CDEBUG(D_INODE, DFID"@%p[%d] -> "DFID"@%p: ostid: "DOSTID
151                " idx: %d gen: %d\n",
152                PFID(&subhdr->coh_lu.loh_fid), subhdr, idx,
153                PFID(&hdr->coh_lu.loh_fid), hdr, POSTID(&oinfo->loi_oi),
154                oinfo->loi_ost_idx, oinfo->loi_ost_gen);
155
156         if (parent == NULL) {
157                 subhdr->coh_parent = hdr;
158                 subhdr->coh_nesting = hdr->coh_nesting + 1;
159                 lu_object_ref_add(&stripe->co_lu, "lov-parent", lov);
160                 r0->lo_sub[idx] = cl2lovsub(stripe);
161                 r0->lo_sub[idx]->lso_super = lov;
162                 r0->lo_sub[idx]->lso_index = idx;
163                 result = 0;
164         } else {
165                 struct lu_object  *old_obj;
166                 struct lov_object *old_lov;
167                 unsigned int mask = D_INODE;
168
169                 old_obj = lu_object_locate(&parent->coh_lu, &lov_device_type);
170                 LASSERT(old_obj != NULL);
171                 old_lov = cl2lov(lu2cl(old_obj));
172                 if (old_lov->lo_layout_invalid) {
173                         /* the object's layout has already changed but isn't
174                          * refreshed */
175                         lu_object_unhash(env, &stripe->co_lu);
176                         result = -EAGAIN;
177                 } else {
178                         mask = D_ERROR;
179                         result = -EIO;
180                 }
181
182                 LU_OBJECT_DEBUG(mask, env, &stripe->co_lu,
183                                 "stripe %d is already owned.\n", idx);
184                 LU_OBJECT_DEBUG(mask, env, old_obj, "owned.\n");
185                 LU_OBJECT_HEADER(mask, env, lov2lu(lov), "try to own.\n");
186                 cl_object_put(env, stripe);
187         }
188         return result;
189 }
190
191 static int lov_init_raid0(const struct lu_env *env,
192                           struct lov_device *dev, struct lov_object *lov,
193                           const struct cl_object_conf *conf,
194                           union  lov_layout_state *state)
195 {
196         int result;
197         int i;
198
199         struct cl_object        *stripe;
200         struct lov_thread_info  *lti     = lov_env_info(env);
201         struct cl_object_conf   *subconf = &lti->lti_stripe_conf;
202         struct lov_stripe_md    *lsm     = conf->u.coc_md->lsm;
203         struct lu_fid      *ofid    = &lti->lti_fid;
204         struct lov_layout_raid0 *r0      = &state->raid0;
205
206         if (lsm->lsm_magic != LOV_MAGIC_V1 && lsm->lsm_magic != LOV_MAGIC_V3) {
207                 dump_lsm(D_ERROR, lsm);
208                 LASSERTF(0, "magic mismatch, expected %d/%d, actual %d.\n",
209                          LOV_MAGIC_V1, LOV_MAGIC_V3, lsm->lsm_magic);
210         }
211
212         LASSERT(lov->lo_lsm == NULL);
213         lov->lo_lsm = lsm_addref(lsm);
214         r0->lo_nr  = lsm->lsm_stripe_count;
215         LASSERT(r0->lo_nr <= lov_targets_nr(dev));
216
217         OBD_ALLOC_LARGE(r0->lo_sub, r0->lo_nr * sizeof(r0->lo_sub[0]));
218         if (r0->lo_sub != NULL) {
219                 result = 0;
220                 subconf->coc_inode = conf->coc_inode;
221                 spin_lock_init(&r0->lo_sub_lock);
222                 /*
223                  * Create stripe cl_objects.
224                  */
225                 for (i = 0; i < r0->lo_nr && result == 0; ++i) {
226                         struct cl_device *subdev;
227                         struct lov_oinfo *oinfo = lsm->lsm_oinfo[i];
228                         int ost_idx = oinfo->loi_ost_idx;
229
230                         result = ostid_to_fid(ofid, &oinfo->loi_oi,
231                                               oinfo->loi_ost_idx);
232                         if (result != 0)
233                                 GOTO(out, result);
234
235                         subdev = lovsub2cl_dev(dev->ld_target[ost_idx]);
236                         subconf->u.coc_oinfo = oinfo;
237                         LASSERTF(subdev != NULL, "not init ost %d\n", ost_idx);
238                         /* In the function below, .hs_keycmp resolves to
239                          * lu_obj_hop_keycmp() */
240                         /* coverity[overrun-buffer-val] */
241                         stripe = lov_sub_find(env, subdev, ofid, subconf);
242                         if (!IS_ERR(stripe)) {
243                                 result = lov_init_sub(env, lov, stripe, r0, i);
244                                 if (result == -EAGAIN) { /* try again */
245                                         --i;
246                                         result = 0;
247                                 }
248                         } else {
249                                 result = PTR_ERR(stripe);
250                         }
251                 }
252         } else
253                 result = -ENOMEM;
254 out:
255         return result;
256 }
257
258 static int lov_init_released(const struct lu_env *env,
259                         struct lov_device *dev, struct lov_object *lov,
260                         const struct cl_object_conf *conf,
261                         union  lov_layout_state *state)
262 {
263         struct lov_stripe_md *lsm = conf->u.coc_md->lsm;
264
265         LASSERT(lsm != NULL);
266         LASSERT(lsm_is_released(lsm));
267         LASSERT(lov->lo_lsm == NULL);
268
269         lov->lo_lsm = lsm_addref(lsm);
270         return 0;
271 }
272
273 static int lov_delete_empty(const struct lu_env *env, struct lov_object *lov,
274                             union lov_layout_state *state)
275 {
276         LASSERT(lov->lo_type == LLT_EMPTY || lov->lo_type == LLT_RELEASED);
277
278         lov_layout_wait(env, lov);
279
280         cl_object_prune(env, &lov->lo_cl);
281         return 0;
282 }
283
284 static void lov_subobject_kill(const struct lu_env *env, struct lov_object *lov,
285                                struct lovsub_object *los, int idx)
286 {
287         struct cl_object        *sub;
288         struct lov_layout_raid0 *r0;
289         struct lu_site    *site;
290         struct lu_site_bkt_data *bkt;
291         wait_queue_t      *waiter;
292
293         r0  = &lov->u.raid0;
294         LASSERT(r0->lo_sub[idx] == los);
295
296         sub  = lovsub2cl(los);
297         site = sub->co_lu.lo_dev->ld_site;
298         bkt  = lu_site_bkt_from_fid(site, &sub->co_lu.lo_header->loh_fid);
299
300         cl_object_kill(env, sub);
301         /* release a reference to the sub-object and ... */
302         lu_object_ref_del(&sub->co_lu, "lov-parent", lov);
303         cl_object_put(env, sub);
304
305         /* ... wait until it is actually destroyed---sub-object clears its
306          * ->lo_sub[] slot in lovsub_object_fini() */
307         if (r0->lo_sub[idx] == los) {
308                 waiter = &lov_env_info(env)->lti_waiter;
309                 init_waitqueue_entry_current(waiter);
310                 add_wait_queue(&bkt->lsb_marche_funebre, waiter);
311                 set_current_state(TASK_UNINTERRUPTIBLE);
312                 while (1) {
313                         /* this wait-queue is signaled at the end of
314                          * lu_object_free(). */
315                         set_current_state(TASK_UNINTERRUPTIBLE);
316                         spin_lock(&r0->lo_sub_lock);
317                         if (r0->lo_sub[idx] == los) {
318                                 spin_unlock(&r0->lo_sub_lock);
319                                 waitq_wait(waiter, TASK_UNINTERRUPTIBLE);
320                         } else {
321                                 spin_unlock(&r0->lo_sub_lock);
322                                 set_current_state(TASK_RUNNING);
323                                 break;
324                         }
325                 }
326                 remove_wait_queue(&bkt->lsb_marche_funebre, waiter);
327         }
328         LASSERT(r0->lo_sub[idx] == NULL);
329 }
330
331 static int lov_delete_raid0(const struct lu_env *env, struct lov_object *lov,
332                             union lov_layout_state *state)
333 {
334         struct lov_layout_raid0 *r0 = &state->raid0;
335         struct lov_stripe_md    *lsm = lov->lo_lsm;
336         int i;
337
338         dump_lsm(D_INODE, lsm);
339
340         lov_layout_wait(env, lov);
341         if (r0->lo_sub != NULL) {
342                 for (i = 0; i < r0->lo_nr; ++i) {
343                         struct lovsub_object *los = r0->lo_sub[i];
344
345                         if (los != NULL) {
346                                 cl_locks_prune(env, &los->lso_cl, 1);
347                                 /*
348                                  * If top-level object is to be evicted from
349                                  * the cache, so are its sub-objects.
350                                  */
351                                 lov_subobject_kill(env, lov, los, i);
352                         }
353                 }
354         }
355         cl_object_prune(env, &lov->lo_cl);
356         return 0;
357 }
358
359 static void lov_fini_empty(const struct lu_env *env, struct lov_object *lov,
360                            union lov_layout_state *state)
361 {
362         LASSERT(lov->lo_type == LLT_EMPTY || lov->lo_type == LLT_RELEASED);
363 }
364
365 static void lov_fini_raid0(const struct lu_env *env, struct lov_object *lov,
366                            union lov_layout_state *state)
367 {
368         struct lov_layout_raid0 *r0 = &state->raid0;
369
370         if (r0->lo_sub != NULL) {
371                 OBD_FREE_LARGE(r0->lo_sub, r0->lo_nr * sizeof(r0->lo_sub[0]));
372                 r0->lo_sub = NULL;
373         }
374
375         dump_lsm(D_INODE, lov->lo_lsm);
376         lov_free_memmd(&lov->lo_lsm);
377 }
378
379 static void lov_fini_released(const struct lu_env *env, struct lov_object *lov,
380                                 union lov_layout_state *state)
381 {
382         dump_lsm(D_INODE, lov->lo_lsm);
383         lov_free_memmd(&lov->lo_lsm);
384 }
385
386 static int lov_print_empty(const struct lu_env *env, void *cookie,
387                            lu_printer_t p, const struct lu_object *o)
388 {
389         (*p)(env, cookie, "empty %d\n", lu2lov(o)->lo_layout_invalid);
390         return 0;
391 }
392
393 static int lov_print_raid0(const struct lu_env *env, void *cookie,
394                            lu_printer_t p, const struct lu_object *o)
395 {
396         struct lov_object       *lov = lu2lov(o);
397         struct lov_layout_raid0 *r0  = lov_r0(lov);
398         struct lov_stripe_md    *lsm = lov->lo_lsm;
399         int i;
400
401         (*p)(env, cookie, "stripes: %d, %svalid, lsm{%p 0x%08X %d %u %u}: \n",
402                 r0->lo_nr, lov->lo_layout_invalid ? "in" : "", lsm,
403                 lsm->lsm_magic, atomic_read(&lsm->lsm_refc),
404                 lsm->lsm_stripe_count, lsm->lsm_layout_gen);
405         for (i = 0; i < r0->lo_nr; ++i) {
406                 struct lu_object *sub;
407
408                 if (r0->lo_sub[i] != NULL) {
409                         sub = lovsub2lu(r0->lo_sub[i]);
410                         lu_object_print(env, cookie, p, sub);
411                 } else
412                         (*p)(env, cookie, "sub %d absent\n", i);
413         }
414         return 0;
415 }
416
417 static int lov_print_released(const struct lu_env *env, void *cookie,
418                                 lu_printer_t p, const struct lu_object *o)
419 {
420         (*p)(env, cookie, "released\n");
421         return 0;
422 }
423
424 /**
425  * Implements cl_object_operations::coo_attr_get() method for an object
426  * without stripes (LLT_EMPTY layout type).
427  *
428  * The only attributes this layer is authoritative in this case is
429  * cl_attr::cat_blocks---it's 0.
430  */
431 static int lov_attr_get_empty(const struct lu_env *env, struct cl_object *obj,
432                               struct cl_attr *attr)
433 {
434         attr->cat_blocks = 0;
435         return 0;
436 }
437
438 static int lov_attr_get_raid0(const struct lu_env *env, struct cl_object *obj,
439                               struct cl_attr *attr)
440 {
441         struct lov_object       *lov = cl2lov(obj);
442         struct lov_layout_raid0 *r0 = lov_r0(lov);
443         struct cl_attr          *lov_attr = &r0->lo_attr;
444         int                      result = 0;
445
446         /* this is called w/o holding type guard mutex, so it must be inside
447          * an on going IO otherwise lsm may be replaced.
448          * LU-2117: it turns out there exists one exception. For mmaped files,
449          * the lock of those files may be requested in the other file's IO
450          * context, and this function is called in ccc_lock_state(), it will
451          * hit this assertion.
452          * Anyway, it's still okay to call attr_get w/o type guard as layout
453          * can't go if locks exist. */
454         /* LASSERT(atomic_read(&lsm->lsm_refc) > 1); */
455
456         if (!r0->lo_attr_valid) {
457                 struct lov_stripe_md    *lsm = lov->lo_lsm;
458                 struct ost_lvb    *lvb = &lov_env_info(env)->lti_lvb;
459                 __u64               kms = 0;
460
461                 memset(lvb, 0, sizeof(*lvb));
462                 /* XXX: timestamps can be negative by sanity:test_39m,
463                  * how can it be? */
464                 lvb->lvb_atime = LLONG_MIN;
465                 lvb->lvb_ctime = LLONG_MIN;
466                 lvb->lvb_mtime = LLONG_MIN;
467
468                 /*
469                  * XXX that should be replaced with a loop over sub-objects,
470                  * doing cl_object_attr_get() on them. But for now, let's
471                  * reuse old lov code.
472                  */
473
474                 /*
475                  * XXX take lsm spin-lock to keep lov_merge_lvb_kms()
476                  * happy. It's not needed, because new code uses
477                  * ->coh_attr_guard spin-lock to protect consistency of
478                  * sub-object attributes.
479                  */
480                 lov_stripe_lock(lsm);
481                 result = lov_merge_lvb_kms(lsm, lvb, &kms);
482                 lov_stripe_unlock(lsm);
483                 if (result == 0) {
484                         cl_lvb2attr(lov_attr, lvb);
485                         lov_attr->cat_kms = kms;
486                         r0->lo_attr_valid = 1;
487                 }
488         }
489         if (result == 0) { /* merge results */
490                 attr->cat_blocks = lov_attr->cat_blocks;
491                 attr->cat_size = lov_attr->cat_size;
492                 attr->cat_kms = lov_attr->cat_kms;
493                 if (attr->cat_atime < lov_attr->cat_atime)
494                         attr->cat_atime = lov_attr->cat_atime;
495                 if (attr->cat_ctime < lov_attr->cat_ctime)
496                         attr->cat_ctime = lov_attr->cat_ctime;
497                 if (attr->cat_mtime < lov_attr->cat_mtime)
498                         attr->cat_mtime = lov_attr->cat_mtime;
499         }
500         return result;
501 }
502
503 const static struct lov_layout_operations lov_dispatch[] = {
504         [LLT_EMPTY] = {
505                 .llo_init      = lov_init_empty,
506                 .llo_delete    = lov_delete_empty,
507                 .llo_fini      = lov_fini_empty,
508                 .llo_install   = lov_install_empty,
509                 .llo_print     = lov_print_empty,
510                 .llo_page_init = lov_page_init_empty,
511                 .llo_lock_init = lov_lock_init_empty,
512                 .llo_io_init   = lov_io_init_empty,
513                 .llo_getattr   = lov_attr_get_empty
514         },
515         [LLT_RAID0] = {
516                 .llo_init      = lov_init_raid0,
517                 .llo_delete    = lov_delete_raid0,
518                 .llo_fini      = lov_fini_raid0,
519                 .llo_install   = lov_install_raid0,
520                 .llo_print     = lov_print_raid0,
521                 .llo_page_init = lov_page_init_raid0,
522                 .llo_lock_init = lov_lock_init_raid0,
523                 .llo_io_init   = lov_io_init_raid0,
524                 .llo_getattr   = lov_attr_get_raid0
525         },
526         [LLT_RELEASED] = {
527                 .llo_init      = lov_init_released,
528                 .llo_delete    = lov_delete_empty,
529                 .llo_fini      = lov_fini_released,
530                 .llo_install   = lov_install_empty,
531                 .llo_print     = lov_print_released,
532                 .llo_page_init = lov_page_init_empty,
533                 .llo_lock_init = lov_lock_init_empty,
534                 .llo_io_init   = lov_io_init_released,
535                 .llo_getattr   = lov_attr_get_empty
536         }
537 };
538
539 /**
540  * Performs a double-dispatch based on the layout type of an object.
541  */
542 #define LOV_2DISPATCH_NOLOCK(obj, op, ...)                            \
543 ({                                                                    \
544         struct lov_object                     *__obj = (obj);     \
545         enum lov_layout_type                __llt;                \
546                                                                         \
547         __llt = __obj->lo_type;                                  \
548         LASSERT(0 <= __llt && __llt < ARRAY_SIZE(lov_dispatch));        \
549         lov_dispatch[__llt].op(__VA_ARGS__);                        \
550 })
551
552 /**
553  * Return lov_layout_type associated with a given lsm
554  */
555 enum lov_layout_type lov_type(struct lov_stripe_md *lsm)
556 {
557         if (lsm == NULL)
558                 return LLT_EMPTY;
559         if (lsm_is_released(lsm))
560                 return LLT_RELEASED;
561         return LLT_RAID0;
562 }
563
564 static inline void lov_conf_freeze(struct lov_object *lov)
565 {
566         if (lov->lo_owner != current)
567                 down_read(&lov->lo_type_guard);
568 }
569
570 static inline void lov_conf_thaw(struct lov_object *lov)
571 {
572         if (lov->lo_owner != current)
573                 up_read(&lov->lo_type_guard);
574 }
575
576 #define LOV_2DISPATCH_MAYLOCK(obj, op, lock, ...)                      \
577 ({                                                                    \
578         struct lov_object                     *__obj = (obj);     \
579         int                                  __lock = !!(lock);      \
580         typeof(lov_dispatch[0].op(__VA_ARGS__)) __result;              \
581                                                                         \
582         if (__lock)                                                  \
583                 lov_conf_freeze(__obj);                                 \
584         __result = LOV_2DISPATCH_NOLOCK(obj, op, __VA_ARGS__);    \
585         if (__lock)                                                  \
586                 lov_conf_thaw(__obj);                                   \
587         __result;                                                      \
588 })
589
590 /**
591  * Performs a locked double-dispatch based on the layout type of an object.
592  */
593 #define LOV_2DISPATCH(obj, op, ...)                  \
594         LOV_2DISPATCH_MAYLOCK(obj, op, 1, __VA_ARGS__)
595
596 #define LOV_2DISPATCH_VOID(obj, op, ...)                                \
597 do {                                                                \
598         struct lov_object                     *__obj = (obj);     \
599         enum lov_layout_type                __llt;                \
600                                                                         \
601         lov_conf_freeze(__obj);                                         \
602         __llt = __obj->lo_type;                                  \
603         LASSERT(0 <= __llt && __llt < ARRAY_SIZE(lov_dispatch));        \
604         lov_dispatch[__llt].op(__VA_ARGS__);                        \
605         lov_conf_thaw(__obj);                                           \
606 } while (0)
607
608 static void lov_conf_lock(struct lov_object *lov)
609 {
610         LASSERT(lov->lo_owner != current);
611         down_write(&lov->lo_type_guard);
612         LASSERT(lov->lo_owner == NULL);
613         lov->lo_owner = current;
614 }
615
616 static void lov_conf_unlock(struct lov_object *lov)
617 {
618         lov->lo_owner = NULL;
619         up_write(&lov->lo_type_guard);
620 }
621
622 static int lov_layout_wait(const struct lu_env *env, struct lov_object *lov)
623 {
624         struct l_wait_info lwi = { 0 };
625
626         while (atomic_read(&lov->lo_active_ios) > 0) {
627                 CDEBUG(D_INODE, "file:"DFID" wait for active IO, now: %d.\n",
628                         PFID(lu_object_fid(lov2lu(lov))),
629                         atomic_read(&lov->lo_active_ios));
630
631                 l_wait_event(lov->lo_waitq,
632                              atomic_read(&lov->lo_active_ios) == 0, &lwi);
633         }
634         return 0;
635 }
636
637 static int lov_layout_change(const struct lu_env *unused,
638                              struct lov_object *lov,
639                              const struct cl_object_conf *conf)
640 {
641         int result;
642         enum lov_layout_type llt = LLT_EMPTY;
643         union lov_layout_state *state = &lov->u;
644         const struct lov_layout_operations *old_ops;
645         const struct lov_layout_operations *new_ops;
646
647         struct cl_object_header *hdr = cl_object_header(&lov->lo_cl);
648         void *cookie;
649         struct lu_env *env;
650         int refcheck;
651
652         LASSERT(0 <= lov->lo_type && lov->lo_type < ARRAY_SIZE(lov_dispatch));
653
654         if (conf->u.coc_md != NULL)
655                 llt = lov_type(conf->u.coc_md->lsm);
656         LASSERT(0 <= llt && llt < ARRAY_SIZE(lov_dispatch));
657
658         cookie = cl_env_reenter();
659         env = cl_env_get(&refcheck);
660         if (IS_ERR(env)) {
661                 cl_env_reexit(cookie);
662                 return PTR_ERR(env);
663         }
664
665         old_ops = &lov_dispatch[lov->lo_type];
666         new_ops = &lov_dispatch[llt];
667
668         result = old_ops->llo_delete(env, lov, &lov->u);
669         if (result == 0) {
670                 old_ops->llo_fini(env, lov, &lov->u);
671
672                 LASSERT(atomic_read(&lov->lo_active_ios) == 0);
673                 LASSERT(hdr->coh_tree.rnode == NULL);
674                 LASSERT(hdr->coh_pages == 0);
675
676                 lov->lo_type = LLT_EMPTY;
677                 result = new_ops->llo_init(env,
678                                         lu2lov_dev(lov->lo_cl.co_lu.lo_dev),
679                                         lov, conf, state);
680                 if (result == 0) {
681                         new_ops->llo_install(env, lov, state);
682                         lov->lo_type = llt;
683                 } else {
684                         new_ops->llo_delete(env, lov, state);
685                         new_ops->llo_fini(env, lov, state);
686                         /* this file becomes an EMPTY file. */
687                 }
688         }
689
690         cl_env_put(env, &refcheck);
691         cl_env_reexit(cookie);
692         return result;
693 }
694
695 /*****************************************************************************
696  *
697  * Lov object operations.
698  *
699  */
700 int lov_object_init(const struct lu_env *env, struct lu_object *obj,
701                     const struct lu_object_conf *conf)
702 {
703         struct lov_device           *dev   = lu2lov_dev(obj->lo_dev);
704         struct lov_object           *lov   = lu2lov(obj);
705         const struct cl_object_conf  *cconf = lu2cl_conf(conf);
706         union  lov_layout_state      *set   = &lov->u;
707         const struct lov_layout_operations *ops;
708         int result;
709
710         init_rwsem(&lov->lo_type_guard);
711         atomic_set(&lov->lo_active_ios, 0);
712         init_waitqueue_head(&lov->lo_waitq);
713
714         cl_object_page_init(lu2cl(obj), sizeof(struct lov_page));
715
716         /* no locking is necessary, as object is being created */
717         lov->lo_type = lov_type(cconf->u.coc_md->lsm);
718         ops = &lov_dispatch[lov->lo_type];
719         result = ops->llo_init(env, dev, lov, cconf, set);
720         if (result == 0)
721                 ops->llo_install(env, lov, set);
722         return result;
723 }
724
725 static int lov_conf_set(const struct lu_env *env, struct cl_object *obj,
726                         const struct cl_object_conf *conf)
727 {
728         struct lov_stripe_md    *lsm = NULL;
729         struct lov_object       *lov = cl2lov(obj);
730         int                      result = 0;
731
732         lov_conf_lock(lov);
733         if (conf->coc_opc == OBJECT_CONF_INVALIDATE) {
734                 lov->lo_layout_invalid = true;
735                 GOTO(out, result = 0);
736         }
737
738         if (conf->coc_opc == OBJECT_CONF_WAIT) {
739                 if (lov->lo_layout_invalid &&
740                     atomic_read(&lov->lo_active_ios) > 0) {
741                         lov_conf_unlock(lov);
742                         result = lov_layout_wait(env, lov);
743                         lov_conf_lock(lov);
744                 }
745                 GOTO(out, result);
746         }
747
748         LASSERT(conf->coc_opc == OBJECT_CONF_SET);
749
750         if (conf->u.coc_md != NULL)
751                 lsm = conf->u.coc_md->lsm;
752         if ((lsm == NULL && lov->lo_lsm == NULL) ||
753             (lsm != NULL && lov->lo_lsm != NULL &&
754              lov->lo_lsm->lsm_layout_gen == lsm->lsm_layout_gen)) {
755                 /* same version of layout */
756                 lov->lo_layout_invalid = false;
757                 GOTO(out, result = 0);
758         }
759
760         /* will change layout - check if there still exists active IO. */
761         if (atomic_read(&lov->lo_active_ios) > 0) {
762                 lov->lo_layout_invalid = true;
763                 GOTO(out, result = -EBUSY);
764         }
765
766         lov->lo_layout_invalid = lov_layout_change(env, lov, conf);
767
768 out:
769         lov_conf_unlock(lov);
770         return result;
771 }
772
773 static void lov_object_delete(const struct lu_env *env, struct lu_object *obj)
774 {
775         struct lov_object *lov = lu2lov(obj);
776
777         LOV_2DISPATCH_VOID(lov, llo_delete, env, lov, &lov->u);
778 }
779
780 static void lov_object_free(const struct lu_env *env, struct lu_object *obj)
781 {
782         struct lov_object *lov = lu2lov(obj);
783
784         LOV_2DISPATCH_VOID(lov, llo_fini, env, lov, &lov->u);
785         lu_object_fini(obj);
786         OBD_SLAB_FREE_PTR(lov, lov_object_kmem);
787 }
788
789 static int lov_object_print(const struct lu_env *env, void *cookie,
790                             lu_printer_t p, const struct lu_object *o)
791 {
792         return LOV_2DISPATCH_NOLOCK(lu2lov(o), llo_print, env, cookie, p, o);
793 }
794
795 int lov_page_init(const struct lu_env *env, struct cl_object *obj,
796                 struct cl_page *page, struct page *vmpage)
797 {
798         return LOV_2DISPATCH_NOLOCK(cl2lov(obj),
799                                     llo_page_init, env, obj, page, vmpage);
800 }
801
802 /**
803  * Implements cl_object_operations::clo_io_init() method for lov
804  * layer. Dispatches to the appropriate layout io initialization method.
805  */
806 int lov_io_init(const struct lu_env *env, struct cl_object *obj,
807                 struct cl_io *io)
808 {
809         CL_IO_SLICE_CLEAN(lov_env_io(env), lis_cl);
810         return LOV_2DISPATCH_MAYLOCK(cl2lov(obj), llo_io_init,
811                                      !io->ci_ignore_layout, env, obj, io);
812 }
813
814 /**
815  * An implementation of cl_object_operations::clo_attr_get() method for lov
816  * layer. For raid0 layout this collects and merges attributes of all
817  * sub-objects.
818  */
819 static int lov_attr_get(const struct lu_env *env, struct cl_object *obj,
820                         struct cl_attr *attr)
821 {
822         /* do not take lock, as this function is called under a
823          * spin-lock. Layout is protected from changing by ongoing IO. */
824         return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_getattr, env, obj, attr);
825 }
826
827 static int lov_attr_set(const struct lu_env *env, struct cl_object *obj,
828                         const struct cl_attr *attr, unsigned valid)
829 {
830         /*
831          * No dispatch is required here, as no layout implements this.
832          */
833         return 0;
834 }
835
836 int lov_lock_init(const struct lu_env *env, struct cl_object *obj,
837                   struct cl_lock *lock, const struct cl_io *io)
838 {
839         /* No need to lock because we've taken one refcount of layout.  */
840         return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_lock_init, env, obj, lock,
841                                     io);
842 }
843
844 static const struct cl_object_operations lov_ops = {
845         .coo_page_init = lov_page_init,
846         .coo_lock_init = lov_lock_init,
847         .coo_io_init   = lov_io_init,
848         .coo_attr_get  = lov_attr_get,
849         .coo_attr_set  = lov_attr_set,
850         .coo_conf_set  = lov_conf_set
851 };
852
853 static const struct lu_object_operations lov_lu_obj_ops = {
854         .loo_object_init      = lov_object_init,
855         .loo_object_delete    = lov_object_delete,
856         .loo_object_release   = NULL,
857         .loo_object_free      = lov_object_free,
858         .loo_object_print     = lov_object_print,
859         .loo_object_invariant = NULL
860 };
861
862 struct lu_object *lov_object_alloc(const struct lu_env *env,
863                                    const struct lu_object_header *unused,
864                                    struct lu_device *dev)
865 {
866         struct lov_object *lov;
867         struct lu_object  *obj;
868
869         OBD_SLAB_ALLOC_PTR_GFP(lov, lov_object_kmem, __GFP_IO);
870         if (lov != NULL) {
871                 obj = lov2lu(lov);
872                 lu_object_init(obj, NULL, dev);
873                 lov->lo_cl.co_ops = &lov_ops;
874                 lov->lo_type = -1; /* invalid, to catch uninitialized type */
875                 /*
876                  * object io operation vector (cl_object::co_iop) is installed
877                  * later in lov_object_init(), as different vectors are used
878                  * for object with different layouts.
879                  */
880                 obj->lo_ops = &lov_lu_obj_ops;
881         } else
882                 obj = NULL;
883         return obj;
884 }
885
886 struct lov_stripe_md *lov_lsm_addref(struct lov_object *lov)
887 {
888         struct lov_stripe_md *lsm = NULL;
889
890         lov_conf_freeze(lov);
891         if (lov->lo_lsm != NULL) {
892                 lsm = lsm_addref(lov->lo_lsm);
893                 CDEBUG(D_INODE, "lsm %p addref %d/%d by %p.\n",
894                         lsm, atomic_read(&lsm->lsm_refc),
895                         lov->lo_layout_invalid, current);
896         }
897         lov_conf_thaw(lov);
898         return lsm;
899 }
900
901 void lov_lsm_decref(struct lov_object *lov, struct lov_stripe_md *lsm)
902 {
903         if (lsm == NULL)
904                 return;
905
906         CDEBUG(D_INODE, "lsm %p decref %d by %p.\n",
907                 lsm, atomic_read(&lsm->lsm_refc), current);
908
909         lov_free_memmd(&lsm);
910 }
911
912 struct lov_stripe_md *lov_lsm_get(struct cl_object *clobj)
913 {
914         struct lu_object *luobj;
915         struct lov_stripe_md *lsm = NULL;
916
917         if (clobj == NULL)
918                 return NULL;
919
920         luobj = lu_object_locate(&cl_object_header(clobj)->coh_lu,
921                                  &lov_device_type);
922         if (luobj != NULL)
923                 lsm = lov_lsm_addref(lu2lov(luobj));
924         return lsm;
925 }
926 EXPORT_SYMBOL(lov_lsm_get);
927
928 void lov_lsm_put(struct cl_object *unused, struct lov_stripe_md *lsm)
929 {
930         if (lsm != NULL)
931                 lov_free_memmd(&lsm);
932 }
933 EXPORT_SYMBOL(lov_lsm_put);
934
935 int lov_read_and_clear_async_rc(struct cl_object *clob)
936 {
937         struct lu_object *luobj;
938         int rc = 0;
939
940         luobj = lu_object_locate(&cl_object_header(clob)->coh_lu,
941                                  &lov_device_type);
942         if (luobj != NULL) {
943                 struct lov_object *lov = lu2lov(luobj);
944
945                 lov_conf_freeze(lov);
946                 switch (lov->lo_type) {
947                 case LLT_RAID0: {
948                         struct lov_stripe_md *lsm;
949                         int i;
950
951                         lsm = lov->lo_lsm;
952                         LASSERT(lsm != NULL);
953                         for (i = 0; i < lsm->lsm_stripe_count; i++) {
954                                 struct lov_oinfo *loi = lsm->lsm_oinfo[i];
955                                 if (loi->loi_ar.ar_rc && !rc)
956                                         rc = loi->loi_ar.ar_rc;
957                                 loi->loi_ar.ar_rc = 0;
958                         }
959                 }
960                 case LLT_RELEASED:
961                 case LLT_EMPTY:
962                         break;
963                 default:
964                         LBUG();
965                 }
966                 lov_conf_thaw(lov);
967         }
968         return rc;
969 }
970 EXPORT_SYMBOL(lov_read_and_clear_async_rc);
971
972 /** @} lov */