linux/fs/ceph/caps.c
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   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/ceph/ceph_debug.h>
   3
   4#include <linux/fs.h>
   5#include <linux/kernel.h>
   6#include <linux/sched/signal.h>
   7#include <linux/slab.h>
   8#include <linux/vmalloc.h>
   9#include <linux/wait.h>
  10#include <linux/writeback.h>
  11#include <linux/iversion.h>
  12
  13#include "super.h"
  14#include "mds_client.h"
  15#include "cache.h"
  16#include <linux/ceph/decode.h>
  17#include <linux/ceph/messenger.h>
  18
  19/*
  20 * Capability management
  21 *
  22 * The Ceph metadata servers control client access to inode metadata
  23 * and file data by issuing capabilities, granting clients permission
  24 * to read and/or write both inode field and file data to OSDs
  25 * (storage nodes).  Each capability consists of a set of bits
  26 * indicating which operations are allowed.
  27 *
  28 * If the client holds a *_SHARED cap, the client has a coherent value
  29 * that can be safely read from the cached inode.
  30 *
  31 * In the case of a *_EXCL (exclusive) or FILE_WR capabilities, the
  32 * client is allowed to change inode attributes (e.g., file size,
  33 * mtime), note its dirty state in the ceph_cap, and asynchronously
  34 * flush that metadata change to the MDS.
  35 *
  36 * In the event of a conflicting operation (perhaps by another
  37 * client), the MDS will revoke the conflicting client capabilities.
  38 *
  39 * In order for a client to cache an inode, it must hold a capability
  40 * with at least one MDS server.  When inodes are released, release
  41 * notifications are batched and periodically sent en masse to the MDS
  42 * cluster to release server state.
  43 */
  44
  45static u64 __get_oldest_flush_tid(struct ceph_mds_client *mdsc);
  46static void __kick_flushing_caps(struct ceph_mds_client *mdsc,
  47                                 struct ceph_mds_session *session,
  48                                 struct ceph_inode_info *ci,
  49                                 u64 oldest_flush_tid);
  50
  51/*
  52 * Generate readable cap strings for debugging output.
  53 */
  54#define MAX_CAP_STR 20
  55static char cap_str[MAX_CAP_STR][40];
  56static DEFINE_SPINLOCK(cap_str_lock);
  57static int last_cap_str;
  58
  59static char *gcap_string(char *s, int c)
  60{
  61        if (c & CEPH_CAP_GSHARED)
  62                *s++ = 's';
  63        if (c & CEPH_CAP_GEXCL)
  64                *s++ = 'x';
  65        if (c & CEPH_CAP_GCACHE)
  66                *s++ = 'c';
  67        if (c & CEPH_CAP_GRD)
  68                *s++ = 'r';
  69        if (c & CEPH_CAP_GWR)
  70                *s++ = 'w';
  71        if (c & CEPH_CAP_GBUFFER)
  72                *s++ = 'b';
  73        if (c & CEPH_CAP_GWREXTEND)
  74                *s++ = 'a';
  75        if (c & CEPH_CAP_GLAZYIO)
  76                *s++ = 'l';
  77        return s;
  78}
  79
  80const char *ceph_cap_string(int caps)
  81{
  82        int i;
  83        char *s;
  84        int c;
  85
  86        spin_lock(&cap_str_lock);
  87        i = last_cap_str++;
  88        if (last_cap_str == MAX_CAP_STR)
  89                last_cap_str = 0;
  90        spin_unlock(&cap_str_lock);
  91
  92        s = cap_str[i];
  93
  94        if (caps & CEPH_CAP_PIN)
  95                *s++ = 'p';
  96
  97        c = (caps >> CEPH_CAP_SAUTH) & 3;
  98        if (c) {
  99                *s++ = 'A';
 100                s = gcap_string(s, c);
 101        }
 102
 103        c = (caps >> CEPH_CAP_SLINK) & 3;
 104        if (c) {
 105                *s++ = 'L';
 106                s = gcap_string(s, c);
 107        }
 108
 109        c = (caps >> CEPH_CAP_SXATTR) & 3;
 110        if (c) {
 111                *s++ = 'X';
 112                s = gcap_string(s, c);
 113        }
 114
 115        c = caps >> CEPH_CAP_SFILE;
 116        if (c) {
 117                *s++ = 'F';
 118                s = gcap_string(s, c);
 119        }
 120
 121        if (s == cap_str[i])
 122                *s++ = '-';
 123        *s = 0;
 124        return cap_str[i];
 125}
 126
 127void ceph_caps_init(struct ceph_mds_client *mdsc)
 128{
 129        INIT_LIST_HEAD(&mdsc->caps_list);
 130        spin_lock_init(&mdsc->caps_list_lock);
 131}
 132
 133void ceph_caps_finalize(struct ceph_mds_client *mdsc)
 134{
 135        struct ceph_cap *cap;
 136
 137        spin_lock(&mdsc->caps_list_lock);
 138        while (!list_empty(&mdsc->caps_list)) {
 139                cap = list_first_entry(&mdsc->caps_list,
 140                                       struct ceph_cap, caps_item);
 141                list_del(&cap->caps_item);
 142                kmem_cache_free(ceph_cap_cachep, cap);
 143        }
 144        mdsc->caps_total_count = 0;
 145        mdsc->caps_avail_count = 0;
 146        mdsc->caps_use_count = 0;
 147        mdsc->caps_reserve_count = 0;
 148        mdsc->caps_min_count = 0;
 149        spin_unlock(&mdsc->caps_list_lock);
 150}
 151
 152void ceph_adjust_caps_max_min(struct ceph_mds_client *mdsc,
 153                              struct ceph_mount_options *fsopt)
 154{
 155        spin_lock(&mdsc->caps_list_lock);
 156        mdsc->caps_min_count = fsopt->max_readdir;
 157        if (mdsc->caps_min_count < 1024)
 158                mdsc->caps_min_count = 1024;
 159        mdsc->caps_use_max = fsopt->caps_max;
 160        if (mdsc->caps_use_max > 0 &&
 161            mdsc->caps_use_max < mdsc->caps_min_count)
 162                mdsc->caps_use_max = mdsc->caps_min_count;
 163        spin_unlock(&mdsc->caps_list_lock);
 164}
 165
 166static void __ceph_unreserve_caps(struct ceph_mds_client *mdsc, int nr_caps)
 167{
 168        struct ceph_cap *cap;
 169        int i;
 170
 171        if (nr_caps) {
 172                BUG_ON(mdsc->caps_reserve_count < nr_caps);
 173                mdsc->caps_reserve_count -= nr_caps;
 174                if (mdsc->caps_avail_count >=
 175                    mdsc->caps_reserve_count + mdsc->caps_min_count) {
 176                        mdsc->caps_total_count -= nr_caps;
 177                        for (i = 0; i < nr_caps; i++) {
 178                                cap = list_first_entry(&mdsc->caps_list,
 179                                        struct ceph_cap, caps_item);
 180                                list_del(&cap->caps_item);
 181                                kmem_cache_free(ceph_cap_cachep, cap);
 182                        }
 183                } else {
 184                        mdsc->caps_avail_count += nr_caps;
 185                }
 186
 187                dout("%s: caps %d = %d used + %d resv + %d avail\n",
 188                     __func__,
 189                     mdsc->caps_total_count, mdsc->caps_use_count,
 190                     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 191                BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 192                                                 mdsc->caps_reserve_count +
 193                                                 mdsc->caps_avail_count);
 194        }
 195}
 196
 197/*
 198 * Called under mdsc->mutex.
 199 */
 200int ceph_reserve_caps(struct ceph_mds_client *mdsc,
 201                      struct ceph_cap_reservation *ctx, int need)
 202{
 203        int i, j;
 204        struct ceph_cap *cap;
 205        int have;
 206        int alloc = 0;
 207        int max_caps;
 208        int err = 0;
 209        bool trimmed = false;
 210        struct ceph_mds_session *s;
 211        LIST_HEAD(newcaps);
 212
 213        dout("reserve caps ctx=%p need=%d\n", ctx, need);
 214
 215        /* first reserve any caps that are already allocated */
 216        spin_lock(&mdsc->caps_list_lock);
 217        if (mdsc->caps_avail_count >= need)
 218                have = need;
 219        else
 220                have = mdsc->caps_avail_count;
 221        mdsc->caps_avail_count -= have;
 222        mdsc->caps_reserve_count += have;
 223        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 224                                         mdsc->caps_reserve_count +
 225                                         mdsc->caps_avail_count);
 226        spin_unlock(&mdsc->caps_list_lock);
 227
 228        for (i = have; i < need; ) {
 229                cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
 230                if (cap) {
 231                        list_add(&cap->caps_item, &newcaps);
 232                        alloc++;
 233                        i++;
 234                        continue;
 235                }
 236
 237                if (!trimmed) {
 238                        for (j = 0; j < mdsc->max_sessions; j++) {
 239                                s = __ceph_lookup_mds_session(mdsc, j);
 240                                if (!s)
 241                                        continue;
 242                                mutex_unlock(&mdsc->mutex);
 243
 244                                mutex_lock(&s->s_mutex);
 245                                max_caps = s->s_nr_caps - (need - i);
 246                                ceph_trim_caps(mdsc, s, max_caps);
 247                                mutex_unlock(&s->s_mutex);
 248
 249                                ceph_put_mds_session(s);
 250                                mutex_lock(&mdsc->mutex);
 251                        }
 252                        trimmed = true;
 253
 254                        spin_lock(&mdsc->caps_list_lock);
 255                        if (mdsc->caps_avail_count) {
 256                                int more_have;
 257                                if (mdsc->caps_avail_count >= need - i)
 258                                        more_have = need - i;
 259                                else
 260                                        more_have = mdsc->caps_avail_count;
 261
 262                                i += more_have;
 263                                have += more_have;
 264                                mdsc->caps_avail_count -= more_have;
 265                                mdsc->caps_reserve_count += more_have;
 266
 267                        }
 268                        spin_unlock(&mdsc->caps_list_lock);
 269
 270                        continue;
 271                }
 272
 273                pr_warn("reserve caps ctx=%p ENOMEM need=%d got=%d\n",
 274                        ctx, need, have + alloc);
 275                err = -ENOMEM;
 276                break;
 277        }
 278
 279        if (!err) {
 280                BUG_ON(have + alloc != need);
 281                ctx->count = need;
 282                ctx->used = 0;
 283        }
 284
 285        spin_lock(&mdsc->caps_list_lock);
 286        mdsc->caps_total_count += alloc;
 287        mdsc->caps_reserve_count += alloc;
 288        list_splice(&newcaps, &mdsc->caps_list);
 289
 290        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 291                                         mdsc->caps_reserve_count +
 292                                         mdsc->caps_avail_count);
 293
 294        if (err)
 295                __ceph_unreserve_caps(mdsc, have + alloc);
 296
 297        spin_unlock(&mdsc->caps_list_lock);
 298
 299        dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
 300             ctx, mdsc->caps_total_count, mdsc->caps_use_count,
 301             mdsc->caps_reserve_count, mdsc->caps_avail_count);
 302        return err;
 303}
 304
 305void ceph_unreserve_caps(struct ceph_mds_client *mdsc,
 306                         struct ceph_cap_reservation *ctx)
 307{
 308        bool reclaim = false;
 309        if (!ctx->count)
 310                return;
 311
 312        dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
 313        spin_lock(&mdsc->caps_list_lock);
 314        __ceph_unreserve_caps(mdsc, ctx->count);
 315        ctx->count = 0;
 316
 317        if (mdsc->caps_use_max > 0 &&
 318            mdsc->caps_use_count > mdsc->caps_use_max)
 319                reclaim = true;
 320        spin_unlock(&mdsc->caps_list_lock);
 321
 322        if (reclaim)
 323                ceph_reclaim_caps_nr(mdsc, ctx->used);
 324}
 325
 326struct ceph_cap *ceph_get_cap(struct ceph_mds_client *mdsc,
 327                              struct ceph_cap_reservation *ctx)
 328{
 329        struct ceph_cap *cap = NULL;
 330
 331        /* temporary, until we do something about cap import/export */
 332        if (!ctx) {
 333                cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
 334                if (cap) {
 335                        spin_lock(&mdsc->caps_list_lock);
 336                        mdsc->caps_use_count++;
 337                        mdsc->caps_total_count++;
 338                        spin_unlock(&mdsc->caps_list_lock);
 339                } else {
 340                        spin_lock(&mdsc->caps_list_lock);
 341                        if (mdsc->caps_avail_count) {
 342                                BUG_ON(list_empty(&mdsc->caps_list));
 343
 344                                mdsc->caps_avail_count--;
 345                                mdsc->caps_use_count++;
 346                                cap = list_first_entry(&mdsc->caps_list,
 347                                                struct ceph_cap, caps_item);
 348                                list_del(&cap->caps_item);
 349
 350                                BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 351                                       mdsc->caps_reserve_count + mdsc->caps_avail_count);
 352                        }
 353                        spin_unlock(&mdsc->caps_list_lock);
 354                }
 355
 356                return cap;
 357        }
 358
 359        spin_lock(&mdsc->caps_list_lock);
 360        dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n",
 361             ctx, ctx->count, mdsc->caps_total_count, mdsc->caps_use_count,
 362             mdsc->caps_reserve_count, mdsc->caps_avail_count);
 363        BUG_ON(!ctx->count);
 364        BUG_ON(ctx->count > mdsc->caps_reserve_count);
 365        BUG_ON(list_empty(&mdsc->caps_list));
 366
 367        ctx->count--;
 368        ctx->used++;
 369        mdsc->caps_reserve_count--;
 370        mdsc->caps_use_count++;
 371
 372        cap = list_first_entry(&mdsc->caps_list, struct ceph_cap, caps_item);
 373        list_del(&cap->caps_item);
 374
 375        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 376               mdsc->caps_reserve_count + mdsc->caps_avail_count);
 377        spin_unlock(&mdsc->caps_list_lock);
 378        return cap;
 379}
 380
 381void ceph_put_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap)
 382{
 383        spin_lock(&mdsc->caps_list_lock);
 384        dout("put_cap %p %d = %d used + %d resv + %d avail\n",
 385             cap, mdsc->caps_total_count, mdsc->caps_use_count,
 386             mdsc->caps_reserve_count, mdsc->caps_avail_count);
 387        mdsc->caps_use_count--;
 388        /*
 389         * Keep some preallocated caps around (ceph_min_count), to
 390         * avoid lots of free/alloc churn.
 391         */
 392        if (mdsc->caps_avail_count >= mdsc->caps_reserve_count +
 393                                      mdsc->caps_min_count) {
 394                mdsc->caps_total_count--;
 395                kmem_cache_free(ceph_cap_cachep, cap);
 396        } else {
 397                mdsc->caps_avail_count++;
 398                list_add(&cap->caps_item, &mdsc->caps_list);
 399        }
 400
 401        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 402               mdsc->caps_reserve_count + mdsc->caps_avail_count);
 403        spin_unlock(&mdsc->caps_list_lock);
 404}
 405
 406void ceph_reservation_status(struct ceph_fs_client *fsc,
 407                             int *total, int *avail, int *used, int *reserved,
 408                             int *min)
 409{
 410        struct ceph_mds_client *mdsc = fsc->mdsc;
 411
 412        spin_lock(&mdsc->caps_list_lock);
 413
 414        if (total)
 415                *total = mdsc->caps_total_count;
 416        if (avail)
 417                *avail = mdsc->caps_avail_count;
 418        if (used)
 419                *used = mdsc->caps_use_count;
 420        if (reserved)
 421                *reserved = mdsc->caps_reserve_count;
 422        if (min)
 423                *min = mdsc->caps_min_count;
 424
 425        spin_unlock(&mdsc->caps_list_lock);
 426}
 427
 428/*
 429 * Find ceph_cap for given mds, if any.
 430 *
 431 * Called with i_ceph_lock held.
 432 */
 433static struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds)
 434{
 435        struct ceph_cap *cap;
 436        struct rb_node *n = ci->i_caps.rb_node;
 437
 438        while (n) {
 439                cap = rb_entry(n, struct ceph_cap, ci_node);
 440                if (mds < cap->mds)
 441                        n = n->rb_left;
 442                else if (mds > cap->mds)
 443                        n = n->rb_right;
 444                else
 445                        return cap;
 446        }
 447        return NULL;
 448}
 449
 450struct ceph_cap *ceph_get_cap_for_mds(struct ceph_inode_info *ci, int mds)
 451{
 452        struct ceph_cap *cap;
 453
 454        spin_lock(&ci->i_ceph_lock);
 455        cap = __get_cap_for_mds(ci, mds);
 456        spin_unlock(&ci->i_ceph_lock);
 457        return cap;
 458}
 459
 460/*
 461 * Called under i_ceph_lock.
 462 */
 463static void __insert_cap_node(struct ceph_inode_info *ci,
 464                              struct ceph_cap *new)
 465{
 466        struct rb_node **p = &ci->i_caps.rb_node;
 467        struct rb_node *parent = NULL;
 468        struct ceph_cap *cap = NULL;
 469
 470        while (*p) {
 471                parent = *p;
 472                cap = rb_entry(parent, struct ceph_cap, ci_node);
 473                if (new->mds < cap->mds)
 474                        p = &(*p)->rb_left;
 475                else if (new->mds > cap->mds)
 476                        p = &(*p)->rb_right;
 477                else
 478                        BUG();
 479        }
 480
 481        rb_link_node(&new->ci_node, parent, p);
 482        rb_insert_color(&new->ci_node, &ci->i_caps);
 483}
 484
 485/*
 486 * (re)set cap hold timeouts, which control the delayed release
 487 * of unused caps back to the MDS.  Should be called on cap use.
 488 */
 489static void __cap_set_timeouts(struct ceph_mds_client *mdsc,
 490                               struct ceph_inode_info *ci)
 491{
 492        struct ceph_mount_options *opt = mdsc->fsc->mount_options;
 493
 494        ci->i_hold_caps_min = round_jiffies(jiffies +
 495                                            opt->caps_wanted_delay_min * HZ);
 496        ci->i_hold_caps_max = round_jiffies(jiffies +
 497                                            opt->caps_wanted_delay_max * HZ);
 498        dout("__cap_set_timeouts %p min %lu max %lu\n", &ci->vfs_inode,
 499             ci->i_hold_caps_min - jiffies, ci->i_hold_caps_max - jiffies);
 500}
 501
 502/*
 503 * (Re)queue cap at the end of the delayed cap release list.
 504 *
 505 * If I_FLUSH is set, leave the inode at the front of the list.
 506 *
 507 * Caller holds i_ceph_lock
 508 *    -> we take mdsc->cap_delay_lock
 509 */
 510static void __cap_delay_requeue(struct ceph_mds_client *mdsc,
 511                                struct ceph_inode_info *ci,
 512                                bool set_timeout)
 513{
 514        dout("__cap_delay_requeue %p flags %d at %lu\n", &ci->vfs_inode,
 515             ci->i_ceph_flags, ci->i_hold_caps_max);
 516        if (!mdsc->stopping) {
 517                spin_lock(&mdsc->cap_delay_lock);
 518                if (!list_empty(&ci->i_cap_delay_list)) {
 519                        if (ci->i_ceph_flags & CEPH_I_FLUSH)
 520                                goto no_change;
 521                        list_del_init(&ci->i_cap_delay_list);
 522                }
 523                if (set_timeout)
 524                        __cap_set_timeouts(mdsc, ci);
 525                list_add_tail(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
 526no_change:
 527                spin_unlock(&mdsc->cap_delay_lock);
 528        }
 529}
 530
 531/*
 532 * Queue an inode for immediate writeback.  Mark inode with I_FLUSH,
 533 * indicating we should send a cap message to flush dirty metadata
 534 * asap, and move to the front of the delayed cap list.
 535 */
 536static void __cap_delay_requeue_front(struct ceph_mds_client *mdsc,
 537                                      struct ceph_inode_info *ci)
 538{
 539        dout("__cap_delay_requeue_front %p\n", &ci->vfs_inode);
 540        spin_lock(&mdsc->cap_delay_lock);
 541        ci->i_ceph_flags |= CEPH_I_FLUSH;
 542        if (!list_empty(&ci->i_cap_delay_list))
 543                list_del_init(&ci->i_cap_delay_list);
 544        list_add(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
 545        spin_unlock(&mdsc->cap_delay_lock);
 546}
 547
 548/*
 549 * Cancel delayed work on cap.
 550 *
 551 * Caller must hold i_ceph_lock.
 552 */
 553static void __cap_delay_cancel(struct ceph_mds_client *mdsc,
 554                               struct ceph_inode_info *ci)
 555{
 556        dout("__cap_delay_cancel %p\n", &ci->vfs_inode);
 557        if (list_empty(&ci->i_cap_delay_list))
 558                return;
 559        spin_lock(&mdsc->cap_delay_lock);
 560        list_del_init(&ci->i_cap_delay_list);
 561        spin_unlock(&mdsc->cap_delay_lock);
 562}
 563
 564/*
 565 * Common issue checks for add_cap, handle_cap_grant.
 566 */
 567static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
 568                              unsigned issued)
 569{
 570        unsigned had = __ceph_caps_issued(ci, NULL);
 571
 572        /*
 573         * Each time we receive FILE_CACHE anew, we increment
 574         * i_rdcache_gen.
 575         */
 576        if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
 577            (had & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0) {
 578                ci->i_rdcache_gen++;
 579        }
 580
 581        /*
 582         * If FILE_SHARED is newly issued, mark dir not complete. We don't
 583         * know what happened to this directory while we didn't have the cap.
 584         * If FILE_SHARED is being revoked, also mark dir not complete. It
 585         * stops on-going cached readdir.
 586         */
 587        if ((issued & CEPH_CAP_FILE_SHARED) != (had & CEPH_CAP_FILE_SHARED)) {
 588                if (issued & CEPH_CAP_FILE_SHARED)
 589                        atomic_inc(&ci->i_shared_gen);
 590                if (S_ISDIR(ci->vfs_inode.i_mode)) {
 591                        dout(" marking %p NOT complete\n", &ci->vfs_inode);
 592                        __ceph_dir_clear_complete(ci);
 593                }
 594        }
 595}
 596
 597/*
 598 * Add a capability under the given MDS session.
 599 *
 600 * Caller should hold session snap_rwsem (read) and ci->i_ceph_lock
 601 *
 602 * @fmode is the open file mode, if we are opening a file, otherwise
 603 * it is < 0.  (This is so we can atomically add the cap and add an
 604 * open file reference to it.)
 605 */
 606void ceph_add_cap(struct inode *inode,
 607                  struct ceph_mds_session *session, u64 cap_id,
 608                  int fmode, unsigned issued, unsigned wanted,
 609                  unsigned seq, unsigned mseq, u64 realmino, int flags,
 610                  struct ceph_cap **new_cap)
 611{
 612        struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 613        struct ceph_inode_info *ci = ceph_inode(inode);
 614        struct ceph_cap *cap;
 615        int mds = session->s_mds;
 616        int actual_wanted;
 617        u32 gen;
 618
 619        lockdep_assert_held(&ci->i_ceph_lock);
 620
 621        dout("add_cap %p mds%d cap %llx %s seq %d\n", inode,
 622             session->s_mds, cap_id, ceph_cap_string(issued), seq);
 623
 624        /*
 625         * If we are opening the file, include file mode wanted bits
 626         * in wanted.
 627         */
 628        if (fmode >= 0)
 629                wanted |= ceph_caps_for_mode(fmode);
 630
 631        spin_lock(&session->s_gen_ttl_lock);
 632        gen = session->s_cap_gen;
 633        spin_unlock(&session->s_gen_ttl_lock);
 634
 635        cap = __get_cap_for_mds(ci, mds);
 636        if (!cap) {
 637                cap = *new_cap;
 638                *new_cap = NULL;
 639
 640                cap->issued = 0;
 641                cap->implemented = 0;
 642                cap->mds = mds;
 643                cap->mds_wanted = 0;
 644                cap->mseq = 0;
 645
 646                cap->ci = ci;
 647                __insert_cap_node(ci, cap);
 648
 649                /* add to session cap list */
 650                cap->session = session;
 651                spin_lock(&session->s_cap_lock);
 652                list_add_tail(&cap->session_caps, &session->s_caps);
 653                session->s_nr_caps++;
 654                spin_unlock(&session->s_cap_lock);
 655        } else {
 656                spin_lock(&session->s_cap_lock);
 657                list_move_tail(&cap->session_caps, &session->s_caps);
 658                spin_unlock(&session->s_cap_lock);
 659
 660                if (cap->cap_gen < gen)
 661                        cap->issued = cap->implemented = CEPH_CAP_PIN;
 662
 663                /*
 664                 * auth mds of the inode changed. we received the cap export
 665                 * message, but still haven't received the cap import message.
 666                 * handle_cap_export() updated the new auth MDS' cap.
 667                 *
 668                 * "ceph_seq_cmp(seq, cap->seq) <= 0" means we are processing
 669                 * a message that was send before the cap import message. So
 670                 * don't remove caps.
 671                 */
 672                if (ceph_seq_cmp(seq, cap->seq) <= 0) {
 673                        WARN_ON(cap != ci->i_auth_cap);
 674                        WARN_ON(cap->cap_id != cap_id);
 675                        seq = cap->seq;
 676                        mseq = cap->mseq;
 677                        issued |= cap->issued;
 678                        flags |= CEPH_CAP_FLAG_AUTH;
 679                }
 680        }
 681
 682        if (!ci->i_snap_realm ||
 683            ((flags & CEPH_CAP_FLAG_AUTH) &&
 684             realmino != (u64)-1 && ci->i_snap_realm->ino != realmino)) {
 685                /*
 686                 * add this inode to the appropriate snap realm
 687                 */
 688                struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc,
 689                                                               realmino);
 690                if (realm) {
 691                        struct ceph_snap_realm *oldrealm = ci->i_snap_realm;
 692                        if (oldrealm) {
 693                                spin_lock(&oldrealm->inodes_with_caps_lock);
 694                                list_del_init(&ci->i_snap_realm_item);
 695                                spin_unlock(&oldrealm->inodes_with_caps_lock);
 696                        }
 697
 698                        spin_lock(&realm->inodes_with_caps_lock);
 699                        list_add(&ci->i_snap_realm_item,
 700                                 &realm->inodes_with_caps);
 701                        ci->i_snap_realm = realm;
 702                        if (realm->ino == ci->i_vino.ino)
 703                                realm->inode = inode;
 704                        spin_unlock(&realm->inodes_with_caps_lock);
 705
 706                        if (oldrealm)
 707                                ceph_put_snap_realm(mdsc, oldrealm);
 708                } else {
 709                        pr_err("ceph_add_cap: couldn't find snap realm %llx\n",
 710                               realmino);
 711                        WARN_ON(!realm);
 712                }
 713        }
 714
 715        __check_cap_issue(ci, cap, issued);
 716
 717        /*
 718         * If we are issued caps we don't want, or the mds' wanted
 719         * value appears to be off, queue a check so we'll release
 720         * later and/or update the mds wanted value.
 721         */
 722        actual_wanted = __ceph_caps_wanted(ci);
 723        if ((wanted & ~actual_wanted) ||
 724            (issued & ~actual_wanted & CEPH_CAP_ANY_WR)) {
 725                dout(" issued %s, mds wanted %s, actual %s, queueing\n",
 726                     ceph_cap_string(issued), ceph_cap_string(wanted),
 727                     ceph_cap_string(actual_wanted));
 728                __cap_delay_requeue(mdsc, ci, true);
 729        }
 730
 731        if (flags & CEPH_CAP_FLAG_AUTH) {
 732                if (!ci->i_auth_cap ||
 733                    ceph_seq_cmp(ci->i_auth_cap->mseq, mseq) < 0) {
 734                        ci->i_auth_cap = cap;
 735                        cap->mds_wanted = wanted;
 736                }
 737        } else {
 738                WARN_ON(ci->i_auth_cap == cap);
 739        }
 740
 741        dout("add_cap inode %p (%llx.%llx) cap %p %s now %s seq %d mds%d\n",
 742             inode, ceph_vinop(inode), cap, ceph_cap_string(issued),
 743             ceph_cap_string(issued|cap->issued), seq, mds);
 744        cap->cap_id = cap_id;
 745        cap->issued = issued;
 746        cap->implemented |= issued;
 747        if (ceph_seq_cmp(mseq, cap->mseq) > 0)
 748                cap->mds_wanted = wanted;
 749        else
 750                cap->mds_wanted |= wanted;
 751        cap->seq = seq;
 752        cap->issue_seq = seq;
 753        cap->mseq = mseq;
 754        cap->cap_gen = gen;
 755
 756        if (fmode >= 0)
 757                __ceph_get_fmode(ci, fmode);
 758}
 759
 760/*
 761 * Return true if cap has not timed out and belongs to the current
 762 * generation of the MDS session (i.e. has not gone 'stale' due to
 763 * us losing touch with the mds).
 764 */
 765static int __cap_is_valid(struct ceph_cap *cap)
 766{
 767        unsigned long ttl;
 768        u32 gen;
 769
 770        spin_lock(&cap->session->s_gen_ttl_lock);
 771        gen = cap->session->s_cap_gen;
 772        ttl = cap->session->s_cap_ttl;
 773        spin_unlock(&cap->session->s_gen_ttl_lock);
 774
 775        if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) {
 776                dout("__cap_is_valid %p cap %p issued %s "
 777                     "but STALE (gen %u vs %u)\n", &cap->ci->vfs_inode,
 778                     cap, ceph_cap_string(cap->issued), cap->cap_gen, gen);
 779                return 0;
 780        }
 781
 782        return 1;
 783}
 784
 785/*
 786 * Return set of valid cap bits issued to us.  Note that caps time
 787 * out, and may be invalidated in bulk if the client session times out
 788 * and session->s_cap_gen is bumped.
 789 */
 790int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented)
 791{
 792        int have = ci->i_snap_caps;
 793        struct ceph_cap *cap;
 794        struct rb_node *p;
 795
 796        if (implemented)
 797                *implemented = 0;
 798        for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 799                cap = rb_entry(p, struct ceph_cap, ci_node);
 800                if (!__cap_is_valid(cap))
 801                        continue;
 802                dout("__ceph_caps_issued %p cap %p issued %s\n",
 803                     &ci->vfs_inode, cap, ceph_cap_string(cap->issued));
 804                have |= cap->issued;
 805                if (implemented)
 806                        *implemented |= cap->implemented;
 807        }
 808        /*
 809         * exclude caps issued by non-auth MDS, but are been revoking
 810         * by the auth MDS. The non-auth MDS should be revoking/exporting
 811         * these caps, but the message is delayed.
 812         */
 813        if (ci->i_auth_cap) {
 814                cap = ci->i_auth_cap;
 815                have &= ~cap->implemented | cap->issued;
 816        }
 817        return have;
 818}
 819
 820/*
 821 * Get cap bits issued by caps other than @ocap
 822 */
 823int __ceph_caps_issued_other(struct ceph_inode_info *ci, struct ceph_cap *ocap)
 824{
 825        int have = ci->i_snap_caps;
 826        struct ceph_cap *cap;
 827        struct rb_node *p;
 828
 829        for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 830                cap = rb_entry(p, struct ceph_cap, ci_node);
 831                if (cap == ocap)
 832                        continue;
 833                if (!__cap_is_valid(cap))
 834                        continue;
 835                have |= cap->issued;
 836        }
 837        return have;
 838}
 839
 840/*
 841 * Move a cap to the end of the LRU (oldest caps at list head, newest
 842 * at list tail).
 843 */
 844static void __touch_cap(struct ceph_cap *cap)
 845{
 846        struct ceph_mds_session *s = cap->session;
 847
 848        spin_lock(&s->s_cap_lock);
 849        if (!s->s_cap_iterator) {
 850                dout("__touch_cap %p cap %p mds%d\n", &cap->ci->vfs_inode, cap,
 851                     s->s_mds);
 852                list_move_tail(&cap->session_caps, &s->s_caps);
 853        } else {
 854                dout("__touch_cap %p cap %p mds%d NOP, iterating over caps\n",
 855                     &cap->ci->vfs_inode, cap, s->s_mds);
 856        }
 857        spin_unlock(&s->s_cap_lock);
 858}
 859
 860/*
 861 * Check if we hold the given mask.  If so, move the cap(s) to the
 862 * front of their respective LRUs.  (This is the preferred way for
 863 * callers to check for caps they want.)
 864 */
 865int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int touch)
 866{
 867        struct ceph_cap *cap;
 868        struct rb_node *p;
 869        int have = ci->i_snap_caps;
 870
 871        if ((have & mask) == mask) {
 872                dout("__ceph_caps_issued_mask ino 0x%lx snap issued %s"
 873                     " (mask %s)\n", ci->vfs_inode.i_ino,
 874                     ceph_cap_string(have),
 875                     ceph_cap_string(mask));
 876                return 1;
 877        }
 878
 879        for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 880                cap = rb_entry(p, struct ceph_cap, ci_node);
 881                if (!__cap_is_valid(cap))
 882                        continue;
 883                if ((cap->issued & mask) == mask) {
 884                        dout("__ceph_caps_issued_mask ino 0x%lx cap %p issued %s"
 885                             " (mask %s)\n", ci->vfs_inode.i_ino, cap,
 886                             ceph_cap_string(cap->issued),
 887                             ceph_cap_string(mask));
 888                        if (touch)
 889                                __touch_cap(cap);
 890                        return 1;
 891                }
 892
 893                /* does a combination of caps satisfy mask? */
 894                have |= cap->issued;
 895                if ((have & mask) == mask) {
 896                        dout("__ceph_caps_issued_mask ino 0x%lx combo issued %s"
 897                             " (mask %s)\n", ci->vfs_inode.i_ino,
 898                             ceph_cap_string(cap->issued),
 899                             ceph_cap_string(mask));
 900                        if (touch) {
 901                                struct rb_node *q;
 902
 903                                /* touch this + preceding caps */
 904                                __touch_cap(cap);
 905                                for (q = rb_first(&ci->i_caps); q != p;
 906                                     q = rb_next(q)) {
 907                                        cap = rb_entry(q, struct ceph_cap,
 908                                                       ci_node);
 909                                        if (!__cap_is_valid(cap))
 910                                                continue;
 911                                        __touch_cap(cap);
 912                                }
 913                        }
 914                        return 1;
 915                }
 916        }
 917
 918        return 0;
 919}
 920
 921/*
 922 * Return true if mask caps are currently being revoked by an MDS.
 923 */
 924int __ceph_caps_revoking_other(struct ceph_inode_info *ci,
 925                               struct ceph_cap *ocap, int mask)
 926{
 927        struct ceph_cap *cap;
 928        struct rb_node *p;
 929
 930        for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 931                cap = rb_entry(p, struct ceph_cap, ci_node);
 932                if (cap != ocap &&
 933                    (cap->implemented & ~cap->issued & mask))
 934                        return 1;
 935        }
 936        return 0;
 937}
 938
 939int ceph_caps_revoking(struct ceph_inode_info *ci, int mask)
 940{
 941        struct inode *inode = &ci->vfs_inode;
 942        int ret;
 943
 944        spin_lock(&ci->i_ceph_lock);
 945        ret = __ceph_caps_revoking_other(ci, NULL, mask);
 946        spin_unlock(&ci->i_ceph_lock);
 947        dout("ceph_caps_revoking %p %s = %d\n", inode,
 948             ceph_cap_string(mask), ret);
 949        return ret;
 950}
 951
 952int __ceph_caps_used(struct ceph_inode_info *ci)
 953{
 954        int used = 0;
 955        if (ci->i_pin_ref)
 956                used |= CEPH_CAP_PIN;
 957        if (ci->i_rd_ref)
 958                used |= CEPH_CAP_FILE_RD;
 959        if (ci->i_rdcache_ref ||
 960            (!S_ISDIR(ci->vfs_inode.i_mode) && /* ignore readdir cache */
 961             ci->vfs_inode.i_data.nrpages))
 962                used |= CEPH_CAP_FILE_CACHE;
 963        if (ci->i_wr_ref)
 964                used |= CEPH_CAP_FILE_WR;
 965        if (ci->i_wb_ref || ci->i_wrbuffer_ref)
 966                used |= CEPH_CAP_FILE_BUFFER;
 967        return used;
 968}
 969
 970/*
 971 * wanted, by virtue of open file modes
 972 */
 973int __ceph_caps_file_wanted(struct ceph_inode_info *ci)
 974{
 975        int i, bits = 0;
 976        for (i = 0; i < CEPH_FILE_MODE_BITS; i++) {
 977                if (ci->i_nr_by_mode[i])
 978                        bits |= 1 << i;
 979        }
 980        if (bits == 0)
 981                return 0;
 982        return ceph_caps_for_mode(bits >> 1);
 983}
 984
 985/*
 986 * Return caps we have registered with the MDS(s) as 'wanted'.
 987 */
 988int __ceph_caps_mds_wanted(struct ceph_inode_info *ci, bool check)
 989{
 990        struct ceph_cap *cap;
 991        struct rb_node *p;
 992        int mds_wanted = 0;
 993
 994        for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 995                cap = rb_entry(p, struct ceph_cap, ci_node);
 996                if (check && !__cap_is_valid(cap))
 997                        continue;
 998                if (cap == ci->i_auth_cap)
 999                        mds_wanted |= cap->mds_wanted;
1000                else
1001                        mds_wanted |= (cap->mds_wanted & ~CEPH_CAP_ANY_FILE_WR);
1002        }
1003        return mds_wanted;
1004}
1005
1006/*
1007 * called under i_ceph_lock
1008 */
1009static int __ceph_is_single_caps(struct ceph_inode_info *ci)
1010{
1011        return rb_first(&ci->i_caps) == rb_last(&ci->i_caps);
1012}
1013
1014static int __ceph_is_any_caps(struct ceph_inode_info *ci)
1015{
1016        return !RB_EMPTY_ROOT(&ci->i_caps);
1017}
1018
1019int ceph_is_any_caps(struct inode *inode)
1020{
1021        struct ceph_inode_info *ci = ceph_inode(inode);
1022        int ret;
1023
1024        spin_lock(&ci->i_ceph_lock);
1025        ret = __ceph_is_any_caps(ci);
1026        spin_unlock(&ci->i_ceph_lock);
1027
1028        return ret;
1029}
1030
1031static void drop_inode_snap_realm(struct ceph_inode_info *ci)
1032{
1033        struct ceph_snap_realm *realm = ci->i_snap_realm;
1034        spin_lock(&realm->inodes_with_caps_lock);
1035        list_del_init(&ci->i_snap_realm_item);
1036        ci->i_snap_realm_counter++;
1037        ci->i_snap_realm = NULL;
1038        if (realm->ino == ci->i_vino.ino)
1039                realm->inode = NULL;
1040        spin_unlock(&realm->inodes_with_caps_lock);
1041        ceph_put_snap_realm(ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc,
1042                            realm);
1043}
1044
1045/*
1046 * Remove a cap.  Take steps to deal with a racing iterate_session_caps.
1047 *
1048 * caller should hold i_ceph_lock.
1049 * caller will not hold session s_mutex if called from destroy_inode.
1050 */
1051void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release)
1052{
1053        struct ceph_mds_session *session = cap->session;
1054        struct ceph_inode_info *ci = cap->ci;
1055        struct ceph_mds_client *mdsc =
1056                ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
1057        int removed = 0;
1058
1059        dout("__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode);
1060
1061        /* remove from inode's cap rbtree, and clear auth cap */
1062        rb_erase(&cap->ci_node, &ci->i_caps);
1063        if (ci->i_auth_cap == cap)
1064                ci->i_auth_cap = NULL;
1065
1066        /* remove from session list */
1067        spin_lock(&session->s_cap_lock);
1068        if (session->s_cap_iterator == cap) {
1069                /* not yet, we are iterating over this very cap */
1070                dout("__ceph_remove_cap  delaying %p removal from session %p\n",
1071                     cap, cap->session);
1072        } else {
1073                list_del_init(&cap->session_caps);
1074                session->s_nr_caps--;
1075                cap->session = NULL;
1076                removed = 1;
1077        }
1078        /* protect backpointer with s_cap_lock: see iterate_session_caps */
1079        cap->ci = NULL;
1080
1081        /*
1082         * s_cap_reconnect is protected by s_cap_lock. no one changes
1083         * s_cap_gen while session is in the reconnect state.
1084         */
1085        if (queue_release &&
1086            (!session->s_cap_reconnect || cap->cap_gen == session->s_cap_gen)) {
1087                cap->queue_release = 1;
1088                if (removed) {
1089                        __ceph_queue_cap_release(session, cap);
1090                        removed = 0;
1091                }
1092        } else {
1093                cap->queue_release = 0;
1094        }
1095        cap->cap_ino = ci->i_vino.ino;
1096
1097        spin_unlock(&session->s_cap_lock);
1098
1099        if (removed)
1100                ceph_put_cap(mdsc, cap);
1101
1102        /* when reconnect denied, we remove session caps forcibly,
1103         * i_wr_ref can be non-zero. If there are ongoing write,
1104         * keep i_snap_realm.
1105         */
1106        if (!__ceph_is_any_caps(ci) && ci->i_wr_ref == 0 && ci->i_snap_realm)
1107                drop_inode_snap_realm(ci);
1108
1109        if (!__ceph_is_any_real_caps(ci))
1110                __cap_delay_cancel(mdsc, ci);
1111}
1112
1113struct cap_msg_args {
1114        struct ceph_mds_session *session;
1115        u64                     ino, cid, follows;
1116        u64                     flush_tid, oldest_flush_tid, size, max_size;
1117        u64                     xattr_version;
1118        u64                     change_attr;
1119        struct ceph_buffer      *xattr_buf;
1120        struct timespec64       atime, mtime, ctime, btime;
1121        int                     op, caps, wanted, dirty;
1122        u32                     seq, issue_seq, mseq, time_warp_seq;
1123        u32                     flags;
1124        kuid_t                  uid;
1125        kgid_t                  gid;
1126        umode_t                 mode;
1127        bool                    inline_data;
1128};
1129
1130/*
1131 * Build and send a cap message to the given MDS.
1132 *
1133 * Caller should be holding s_mutex.
1134 */
1135static int send_cap_msg(struct cap_msg_args *arg)
1136{
1137        struct ceph_mds_caps *fc;
1138        struct ceph_msg *msg;
1139        void *p;
1140        size_t extra_len;
1141        struct ceph_osd_client *osdc = &arg->session->s_mdsc->fsc->client->osdc;
1142
1143        dout("send_cap_msg %s %llx %llx caps %s wanted %s dirty %s"
1144             " seq %u/%u tid %llu/%llu mseq %u follows %lld size %llu/%llu"
1145             " xattr_ver %llu xattr_len %d\n", ceph_cap_op_name(arg->op),
1146             arg->cid, arg->ino, ceph_cap_string(arg->caps),
1147             ceph_cap_string(arg->wanted), ceph_cap_string(arg->dirty),
1148             arg->seq, arg->issue_seq, arg->flush_tid, arg->oldest_flush_tid,
1149             arg->mseq, arg->follows, arg->size, arg->max_size,
1150             arg->xattr_version,
1151             arg->xattr_buf ? (int)arg->xattr_buf->vec.iov_len : 0);
1152
1153        /* flock buffer size + inline version + inline data size +
1154         * osd_epoch_barrier + oldest_flush_tid */
1155        extra_len = 4 + 8 + 4 + 4 + 8 + 4 + 4 + 4 + 8 + 8 + 4;
1156        msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc) + extra_len,
1157                           GFP_NOFS, false);
1158        if (!msg)
1159                return -ENOMEM;
1160
1161        msg->hdr.version = cpu_to_le16(10);
1162        msg->hdr.tid = cpu_to_le64(arg->flush_tid);
1163
1164        fc = msg->front.iov_base;
1165        memset(fc, 0, sizeof(*fc));
1166
1167        fc->cap_id = cpu_to_le64(arg->cid);
1168        fc->op = cpu_to_le32(arg->op);
1169        fc->seq = cpu_to_le32(arg->seq);
1170        fc->issue_seq = cpu_to_le32(arg->issue_seq);
1171        fc->migrate_seq = cpu_to_le32(arg->mseq);
1172        fc->caps = cpu_to_le32(arg->caps);
1173        fc->wanted = cpu_to_le32(arg->wanted);
1174        fc->dirty = cpu_to_le32(arg->dirty);
1175        fc->ino = cpu_to_le64(arg->ino);
1176        fc->snap_follows = cpu_to_le64(arg->follows);
1177
1178        fc->size = cpu_to_le64(arg->size);
1179        fc->max_size = cpu_to_le64(arg->max_size);
1180        ceph_encode_timespec64(&fc->mtime, &arg->mtime);
1181        ceph_encode_timespec64(&fc->atime, &arg->atime);
1182        ceph_encode_timespec64(&fc->ctime, &arg->ctime);
1183        fc->time_warp_seq = cpu_to_le32(arg->time_warp_seq);
1184
1185        fc->uid = cpu_to_le32(from_kuid(&init_user_ns, arg->uid));
1186        fc->gid = cpu_to_le32(from_kgid(&init_user_ns, arg->gid));
1187        fc->mode = cpu_to_le32(arg->mode);
1188
1189        fc->xattr_version = cpu_to_le64(arg->xattr_version);
1190        if (arg->xattr_buf) {
1191                msg->middle = ceph_buffer_get(arg->xattr_buf);
1192                fc->xattr_len = cpu_to_le32(arg->xattr_buf->vec.iov_len);
1193                msg->hdr.middle_len = cpu_to_le32(arg->xattr_buf->vec.iov_len);
1194        }
1195
1196        p = fc + 1;
1197        /* flock buffer size (version 2) */
1198        ceph_encode_32(&p, 0);
1199        /* inline version (version 4) */
1200        ceph_encode_64(&p, arg->inline_data ? 0 : CEPH_INLINE_NONE);
1201        /* inline data size */
1202        ceph_encode_32(&p, 0);
1203        /*
1204         * osd_epoch_barrier (version 5)
1205         * The epoch_barrier is protected osdc->lock, so READ_ONCE here in
1206         * case it was recently changed
1207         */
1208        ceph_encode_32(&p, READ_ONCE(osdc->epoch_barrier));
1209        /* oldest_flush_tid (version 6) */
1210        ceph_encode_64(&p, arg->oldest_flush_tid);
1211
1212        /*
1213         * caller_uid/caller_gid (version 7)
1214         *
1215         * Currently, we don't properly track which caller dirtied the caps
1216         * last, and force a flush of them when there is a conflict. For now,
1217         * just set this to 0:0, to emulate how the MDS has worked up to now.
1218         */
1219        ceph_encode_32(&p, 0);
1220        ceph_encode_32(&p, 0);
1221
1222        /* pool namespace (version 8) (mds always ignores this) */
1223        ceph_encode_32(&p, 0);
1224
1225        /* btime and change_attr (version 9) */
1226        ceph_encode_timespec64(p, &arg->btime);
1227        p += sizeof(struct ceph_timespec);
1228        ceph_encode_64(&p, arg->change_attr);
1229
1230        /* Advisory flags (version 10) */
1231        ceph_encode_32(&p, arg->flags);
1232
1233        ceph_con_send(&arg->session->s_con, msg);
1234        return 0;
1235}
1236
1237/*
1238 * Queue cap releases when an inode is dropped from our cache.
1239 */
1240void __ceph_remove_caps(struct ceph_inode_info *ci)
1241{
1242        struct rb_node *p;
1243
1244        /* lock i_ceph_lock, because ceph_d_revalidate(..., LOOKUP_RCU)
1245         * may call __ceph_caps_issued_mask() on a freeing inode. */
1246        spin_lock(&ci->i_ceph_lock);
1247        p = rb_first(&ci->i_caps);
1248        while (p) {
1249                struct ceph_cap *cap = rb_entry(p, struct ceph_cap, ci_node);
1250                p = rb_next(p);
1251                __ceph_remove_cap(cap, true);
1252        }
1253        spin_unlock(&ci->i_ceph_lock);
1254}
1255
1256/*
1257 * Send a cap msg on the given inode.  Update our caps state, then
1258 * drop i_ceph_lock and send the message.
1259 *
1260 * Make note of max_size reported/requested from mds, revoked caps
1261 * that have now been implemented.
1262 *
1263 * Return non-zero if delayed release, or we experienced an error
1264 * such that the caller should requeue + retry later.
1265 *
1266 * called with i_ceph_lock, then drops it.
1267 * caller should hold snap_rwsem (read), s_mutex.
1268 */
1269static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
1270                      int op, int flags, int used, int want, int retain,
1271                      int flushing, u64 flush_tid, u64 oldest_flush_tid)
1272        __releases(cap->ci->i_ceph_lock)
1273{
1274        struct ceph_inode_info *ci = cap->ci;
1275        struct inode *inode = &ci->vfs_inode;
1276        struct ceph_buffer *old_blob = NULL;
1277        struct cap_msg_args arg;
1278        int held, revoking;
1279        int wake = 0;
1280        int delayed = 0;
1281        int ret;
1282
1283        held = cap->issued | cap->implemented;
1284        revoking = cap->implemented & ~cap->issued;
1285        retain &= ~revoking;
1286
1287        dout("__send_cap %p cap %p session %p %s -> %s (revoking %s)\n",
1288             inode, cap, cap->session,
1289             ceph_cap_string(held), ceph_cap_string(held & retain),
1290             ceph_cap_string(revoking));
1291        BUG_ON((retain & CEPH_CAP_PIN) == 0);
1292
1293        arg.session = cap->session;
1294
1295        /* don't release wanted unless we've waited a bit. */
1296        if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1297            time_before(jiffies, ci->i_hold_caps_min)) {
1298                dout(" delaying issued %s -> %s, wanted %s -> %s on send\n",
1299                     ceph_cap_string(cap->issued),
1300                     ceph_cap_string(cap->issued & retain),
1301                     ceph_cap_string(cap->mds_wanted),
1302                     ceph_cap_string(want));
1303                want |= cap->mds_wanted;
1304                retain |= cap->issued;
1305                delayed = 1;
1306        }
1307        ci->i_ceph_flags &= ~(CEPH_I_NODELAY | CEPH_I_FLUSH);
1308        if (want & ~cap->mds_wanted) {
1309                /* user space may open/close single file frequently.
1310                 * This avoids droping mds_wanted immediately after
1311                 * requesting new mds_wanted.
1312                 */
1313                __cap_set_timeouts(mdsc, ci);
1314        }
1315
1316        cap->issued &= retain;  /* drop bits we don't want */
1317        if (cap->implemented & ~cap->issued) {
1318                /*
1319                 * Wake up any waiters on wanted -> needed transition.
1320                 * This is due to the weird transition from buffered
1321                 * to sync IO... we need to flush dirty pages _before_
1322                 * allowing sync writes to avoid reordering.
1323                 */
1324                wake = 1;
1325        }
1326        cap->implemented &= cap->issued | used;
1327        cap->mds_wanted = want;
1328
1329        arg.ino = ceph_vino(inode).ino;
1330        arg.cid = cap->cap_id;
1331        arg.follows = flushing ? ci->i_head_snapc->seq : 0;
1332        arg.flush_tid = flush_tid;
1333        arg.oldest_flush_tid = oldest_flush_tid;
1334
1335        arg.size = inode->i_size;
1336        ci->i_reported_size = arg.size;
1337        arg.max_size = ci->i_wanted_max_size;
1338        ci->i_requested_max_size = arg.max_size;
1339
1340        if (flushing & CEPH_CAP_XATTR_EXCL) {
1341                old_blob = __ceph_build_xattrs_blob(ci);
1342                arg.xattr_version = ci->i_xattrs.version;
1343                arg.xattr_buf = ci->i_xattrs.blob;
1344        } else {
1345                arg.xattr_buf = NULL;
1346        }
1347
1348        arg.mtime = inode->i_mtime;
1349        arg.atime = inode->i_atime;
1350        arg.ctime = inode->i_ctime;
1351        arg.btime = ci->i_btime;
1352        arg.change_attr = inode_peek_iversion_raw(inode);
1353
1354        arg.op = op;
1355        arg.caps = cap->implemented;
1356        arg.wanted = want;
1357        arg.dirty = flushing;
1358
1359        arg.seq = cap->seq;
1360        arg.issue_seq = cap->issue_seq;
1361        arg.mseq = cap->mseq;
1362        arg.time_warp_seq = ci->i_time_warp_seq;
1363
1364        arg.uid = inode->i_uid;
1365        arg.gid = inode->i_gid;
1366        arg.mode = inode->i_mode;
1367
1368        arg.inline_data = ci->i_inline_version != CEPH_INLINE_NONE;
1369        if (!(flags & CEPH_CLIENT_CAPS_PENDING_CAPSNAP) &&
1370            !list_empty(&ci->i_cap_snaps)) {
1371                struct ceph_cap_snap *capsnap;
1372                list_for_each_entry_reverse(capsnap, &ci->i_cap_snaps, ci_item) {
1373                        if (capsnap->cap_flush.tid)
1374                                break;
1375                        if (capsnap->need_flush) {
1376                                flags |= CEPH_CLIENT_CAPS_PENDING_CAPSNAP;
1377                                break;
1378                        }
1379                }
1380        }
1381        arg.flags = flags;
1382
1383        spin_unlock(&ci->i_ceph_lock);
1384
1385        ceph_buffer_put(old_blob);
1386
1387        ret = send_cap_msg(&arg);
1388        if (ret < 0) {
1389                dout("error sending cap msg, must requeue %p\n", inode);
1390                delayed = 1;
1391        }
1392
1393        if (wake)
1394                wake_up_all(&ci->i_cap_wq);
1395
1396        return delayed;
1397}
1398
1399static inline int __send_flush_snap(struct inode *inode,
1400                                    struct ceph_mds_session *session,
1401                                    struct ceph_cap_snap *capsnap,
1402                                    u32 mseq, u64 oldest_flush_tid)
1403{
1404        struct cap_msg_args     arg;
1405
1406        arg.session = session;
1407        arg.ino = ceph_vino(inode).ino;
1408        arg.cid = 0;
1409        arg.follows = capsnap->follows;
1410        arg.flush_tid = capsnap->cap_flush.tid;
1411        arg.oldest_flush_tid = oldest_flush_tid;
1412
1413        arg.size = capsnap->size;
1414        arg.max_size = 0;
1415        arg.xattr_version = capsnap->xattr_version;
1416        arg.xattr_buf = capsnap->xattr_blob;
1417
1418        arg.atime = capsnap->atime;
1419        arg.mtime = capsnap->mtime;
1420        arg.ctime = capsnap->ctime;
1421        arg.btime = capsnap->btime;
1422        arg.change_attr = capsnap->change_attr;
1423
1424        arg.op = CEPH_CAP_OP_FLUSHSNAP;
1425        arg.caps = capsnap->issued;
1426        arg.wanted = 0;
1427        arg.dirty = capsnap->dirty;
1428
1429        arg.seq = 0;
1430        arg.issue_seq = 0;
1431        arg.mseq = mseq;
1432        arg.time_warp_seq = capsnap->time_warp_seq;
1433
1434        arg.uid = capsnap->uid;
1435        arg.gid = capsnap->gid;
1436        arg.mode = capsnap->mode;
1437
1438        arg.inline_data = capsnap->inline_data;
1439        arg.flags = 0;
1440
1441        return send_cap_msg(&arg);
1442}
1443
1444/*
1445 * When a snapshot is taken, clients accumulate dirty metadata on
1446 * inodes with capabilities in ceph_cap_snaps to describe the file
1447 * state at the time the snapshot was taken.  This must be flushed
1448 * asynchronously back to the MDS once sync writes complete and dirty
1449 * data is written out.
1450 *
1451 * Called under i_ceph_lock.  Takes s_mutex as needed.
1452 */
1453static void __ceph_flush_snaps(struct ceph_inode_info *ci,
1454                               struct ceph_mds_session *session)
1455                __releases(ci->i_ceph_lock)
1456                __acquires(ci->i_ceph_lock)
1457{
1458        struct inode *inode = &ci->vfs_inode;
1459        struct ceph_mds_client *mdsc = session->s_mdsc;
1460        struct ceph_cap_snap *capsnap;
1461        u64 oldest_flush_tid = 0;
1462        u64 first_tid = 1, last_tid = 0;
1463
1464        dout("__flush_snaps %p session %p\n", inode, session);
1465
1466        list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
1467                /*
1468                 * we need to wait for sync writes to complete and for dirty
1469                 * pages to be written out.
1470                 */
1471                if (capsnap->dirty_pages || capsnap->writing)
1472                        break;
1473
1474                /* should be removed by ceph_try_drop_cap_snap() */
1475                BUG_ON(!capsnap->need_flush);
1476
1477                /* only flush each capsnap once */
1478                if (capsnap->cap_flush.tid > 0) {
1479                        dout(" already flushed %p, skipping\n", capsnap);
1480                        continue;
1481                }
1482
1483                spin_lock(&mdsc->cap_dirty_lock);
1484                capsnap->cap_flush.tid = ++mdsc->last_cap_flush_tid;
1485                list_add_tail(&capsnap->cap_flush.g_list,
1486                              &mdsc->cap_flush_list);
1487                if (oldest_flush_tid == 0)
1488                        oldest_flush_tid = __get_oldest_flush_tid(mdsc);
1489                if (list_empty(&ci->i_flushing_item)) {
1490                        list_add_tail(&ci->i_flushing_item,
1491                                      &session->s_cap_flushing);
1492                }
1493                spin_unlock(&mdsc->cap_dirty_lock);
1494
1495                list_add_tail(&capsnap->cap_flush.i_list,
1496                              &ci->i_cap_flush_list);
1497
1498                if (first_tid == 1)
1499                        first_tid = capsnap->cap_flush.tid;
1500                last_tid = capsnap->cap_flush.tid;
1501        }
1502
1503        ci->i_ceph_flags &= ~CEPH_I_FLUSH_SNAPS;
1504
1505        while (first_tid <= last_tid) {
1506                struct ceph_cap *cap = ci->i_auth_cap;
1507                struct ceph_cap_flush *cf;
1508                int ret;
1509
1510                if (!(cap && cap->session == session)) {
1511                        dout("__flush_snaps %p auth cap %p not mds%d, "
1512                             "stop\n", inode, cap, session->s_mds);
1513                        break;
1514                }
1515
1516                ret = -ENOENT;
1517                list_for_each_entry(cf, &ci->i_cap_flush_list, i_list) {
1518                        if (cf->tid >= first_tid) {
1519                                ret = 0;
1520                                break;
1521                        }
1522                }
1523                if (ret < 0)
1524                        break;
1525
1526                first_tid = cf->tid + 1;
1527
1528                capsnap = container_of(cf, struct ceph_cap_snap, cap_flush);
1529                refcount_inc(&capsnap->nref);
1530                spin_unlock(&ci->i_ceph_lock);
1531
1532                dout("__flush_snaps %p capsnap %p tid %llu %s\n",
1533                     inode, capsnap, cf->tid, ceph_cap_string(capsnap->dirty));
1534
1535                ret = __send_flush_snap(inode, session, capsnap, cap->mseq,
1536                                        oldest_flush_tid);
1537                if (ret < 0) {
1538                        pr_err("__flush_snaps: error sending cap flushsnap, "
1539                               "ino (%llx.%llx) tid %llu follows %llu\n",
1540                                ceph_vinop(inode), cf->tid, capsnap->follows);
1541                }
1542
1543                ceph_put_cap_snap(capsnap);
1544                spin_lock(&ci->i_ceph_lock);
1545        }
1546}
1547
1548void ceph_flush_snaps(struct ceph_inode_info *ci,
1549                      struct ceph_mds_session **psession)
1550{
1551        struct inode *inode = &ci->vfs_inode;
1552        struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
1553        struct ceph_mds_session *session = NULL;
1554        int mds;
1555
1556        dout("ceph_flush_snaps %p\n", inode);
1557        if (psession)
1558                session = *psession;
1559retry:
1560        spin_lock(&ci->i_ceph_lock);
1561        if (!(ci->i_ceph_flags & CEPH_I_FLUSH_SNAPS)) {
1562                dout(" no capsnap needs flush, doing nothing\n");
1563                goto out;
1564        }
1565        if (!ci->i_auth_cap) {
1566                dout(" no auth cap (migrating?), doing nothing\n");
1567                goto out;
1568        }
1569
1570        mds = ci->i_auth_cap->session->s_mds;
1571        if (session && session->s_mds != mds) {
1572                dout(" oops, wrong session %p mutex\n", session);
1573                mutex_unlock(&session->s_mutex);
1574                ceph_put_mds_session(session);
1575                session = NULL;
1576        }
1577        if (!session) {
1578                spin_unlock(&ci->i_ceph_lock);
1579                mutex_lock(&mdsc->mutex);
1580                session = __ceph_lookup_mds_session(mdsc, mds);
1581                mutex_unlock(&mdsc->mutex);
1582                if (session) {
1583                        dout(" inverting session/ino locks on %p\n", session);
1584                        mutex_lock(&session->s_mutex);
1585                }
1586                goto retry;
1587        }
1588
1589        // make sure flushsnap messages are sent in proper order.
1590        if (ci->i_ceph_flags & CEPH_I_KICK_FLUSH)
1591                __kick_flushing_caps(mdsc, session, ci, 0);
1592
1593        __ceph_flush_snaps(ci, session);
1594out:
1595        spin_unlock(&ci->i_ceph_lock);
1596
1597        if (psession) {
1598                *psession = session;
1599        } else if (session) {
1600                mutex_unlock(&session->s_mutex);
1601                ceph_put_mds_session(session);
1602        }
1603        /* we flushed them all; remove this inode from the queue */
1604        spin_lock(&mdsc->snap_flush_lock);
1605        list_del_init(&ci->i_snap_flush_item);
1606        spin_unlock(&mdsc->snap_flush_lock);
1607}
1608
1609/*
1610 * Mark caps dirty.  If inode is newly dirty, return the dirty flags.
1611 * Caller is then responsible for calling __mark_inode_dirty with the
1612 * returned flags value.
1613 */
1614int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask,
1615                           struct ceph_cap_flush **pcf)
1616{
1617        struct ceph_mds_client *mdsc =
1618                ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
1619        struct inode *inode = &ci->vfs_inode;
1620        int was = ci->i_dirty_caps;
1621        int dirty = 0;
1622
1623        if (!ci->i_auth_cap) {
1624                pr_warn("__mark_dirty_caps %p %llx mask %s, "
1625                        "but no auth cap (session was closed?)\n",
1626                        inode, ceph_ino(inode), ceph_cap_string(mask));
1627                return 0;
1628        }
1629
1630        dout("__mark_dirty_caps %p %s dirty %s -> %s\n", &ci->vfs_inode,
1631             ceph_cap_string(mask), ceph_cap_string(was),
1632             ceph_cap_string(was | mask));
1633        ci->i_dirty_caps |= mask;
1634        if (was == 0) {
1635                WARN_ON_ONCE(ci->i_prealloc_cap_flush);
1636                swap(ci->i_prealloc_cap_flush, *pcf);
1637
1638                if (!ci->i_head_snapc) {
1639                        WARN_ON_ONCE(!rwsem_is_locked(&mdsc->snap_rwsem));
1640                        ci->i_head_snapc = ceph_get_snap_context(
1641                                ci->i_snap_realm->cached_context);
1642                }
1643                dout(" inode %p now dirty snapc %p auth cap %p\n",
1644                     &ci->vfs_inode, ci->i_head_snapc, ci->i_auth_cap);
1645                BUG_ON(!list_empty(&ci->i_dirty_item));
1646                spin_lock(&mdsc->cap_dirty_lock);
1647                list_add(&ci->i_dirty_item, &mdsc->cap_dirty);
1648                spin_unlock(&mdsc->cap_dirty_lock);
1649                if (ci->i_flushing_caps == 0) {
1650                        ihold(inode);
1651                        dirty |= I_DIRTY_SYNC;
1652                }
1653        } else {
1654                WARN_ON_ONCE(!ci->i_prealloc_cap_flush);
1655        }
1656        BUG_ON(list_empty(&ci->i_dirty_item));
1657        if (((was | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) &&
1658            (mask & CEPH_CAP_FILE_BUFFER))
1659                dirty |= I_DIRTY_DATASYNC;
1660        __cap_delay_requeue(mdsc, ci, true);
1661        return dirty;
1662}
1663
1664struct ceph_cap_flush *ceph_alloc_cap_flush(void)
1665{
1666        return kmem_cache_alloc(ceph_cap_flush_cachep, GFP_KERNEL);
1667}
1668
1669void ceph_free_cap_flush(struct ceph_cap_flush *cf)
1670{
1671        if (cf)
1672                kmem_cache_free(ceph_cap_flush_cachep, cf);
1673}
1674
1675static u64 __get_oldest_flush_tid(struct ceph_mds_client *mdsc)
1676{
1677        if (!list_empty(&mdsc->cap_flush_list)) {
1678                struct ceph_cap_flush *cf =
1679                        list_first_entry(&mdsc->cap_flush_list,
1680                                         struct ceph_cap_flush, g_list);
1681                return cf->tid;
1682        }
1683        return 0;
1684}
1685
1686/*
1687 * Remove cap_flush from the mdsc's or inode's flushing cap list.
1688 * Return true if caller needs to wake up flush waiters.
1689 */
1690static bool __finish_cap_flush(struct ceph_mds_client *mdsc,
1691                               struct ceph_inode_info *ci,
1692                               struct ceph_cap_flush *cf)
1693{
1694        struct ceph_cap_flush *prev;
1695        bool wake = cf->wake;
1696        if (mdsc) {
1697                /* are there older pending cap flushes? */
1698                if (wake && cf->g_list.prev != &mdsc->cap_flush_list) {
1699                        prev = list_prev_entry(cf, g_list);
1700                        prev->wake = true;
1701                        wake = false;
1702                }
1703                list_del(&cf->g_list);
1704        } else if (ci) {
1705                if (wake && cf->i_list.prev != &ci->i_cap_flush_list) {
1706                        prev = list_prev_entry(cf, i_list);
1707                        prev->wake = true;
1708                        wake = false;
1709                }
1710                list_del(&cf->i_list);
1711        } else {
1712                BUG_ON(1);
1713        }
1714        return wake;
1715}
1716
1717/*
1718 * Add dirty inode to the flushing list.  Assigned a seq number so we
1719 * can wait for caps to flush without starving.
1720 *
1721 * Called under i_ceph_lock. Returns the flush tid.
1722 */
1723static u64 __mark_caps_flushing(struct inode *inode,
1724                                struct ceph_mds_session *session, bool wake,
1725                                u64 *oldest_flush_tid)
1726{
1727        struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
1728        struct ceph_inode_info *ci = ceph_inode(inode);
1729        struct ceph_cap_flush *cf = NULL;
1730        int flushing;
1731
1732        BUG_ON(ci->i_dirty_caps == 0);
1733        BUG_ON(list_empty(&ci->i_dirty_item));
1734        BUG_ON(!ci->i_prealloc_cap_flush);
1735
1736        flushing = ci->i_dirty_caps;
1737        dout("__mark_caps_flushing flushing %s, flushing_caps %s -> %s\n",
1738             ceph_cap_string(flushing),
1739             ceph_cap_string(ci->i_flushing_caps),
1740             ceph_cap_string(ci->i_flushing_caps | flushing));
1741        ci->i_flushing_caps |= flushing;
1742        ci->i_dirty_caps = 0;
1743        dout(" inode %p now !dirty\n", inode);
1744
1745        swap(cf, ci->i_prealloc_cap_flush);
1746        cf->caps = flushing;
1747        cf->wake = wake;
1748
1749        spin_lock(&mdsc->cap_dirty_lock);
1750        list_del_init(&ci->i_dirty_item);
1751
1752        cf->tid = ++mdsc->last_cap_flush_tid;
1753        list_add_tail(&cf->g_list, &mdsc->cap_flush_list);
1754        *oldest_flush_tid = __get_oldest_flush_tid(mdsc);
1755
1756        if (list_empty(&ci->i_flushing_item)) {
1757                list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1758                mdsc->num_cap_flushing++;
1759        }
1760        spin_unlock(&mdsc->cap_dirty_lock);
1761
1762        list_add_tail(&cf->i_list, &ci->i_cap_flush_list);
1763
1764        return cf->tid;
1765}
1766
1767/*
1768 * try to invalidate mapping pages without blocking.
1769 */
1770static int try_nonblocking_invalidate(struct inode *inode)
1771{
1772        struct ceph_inode_info *ci = ceph_inode(inode);
1773        u32 invalidating_gen = ci->i_rdcache_gen;
1774
1775        spin_unlock(&ci->i_ceph_lock);
1776        invalidate_mapping_pages(&inode->i_data, 0, -1);
1777        spin_lock(&ci->i_ceph_lock);
1778
1779        if (inode->i_data.nrpages == 0 &&
1780            invalidating_gen == ci->i_rdcache_gen) {
1781                /* success. */
1782                dout("try_nonblocking_invalidate %p success\n", inode);
1783                /* save any racing async invalidate some trouble */
1784                ci->i_rdcache_revoking = ci->i_rdcache_gen - 1;
1785                return 0;
1786        }
1787        dout("try_nonblocking_invalidate %p failed\n", inode);
1788        return -1;
1789}
1790
1791bool __ceph_should_report_size(struct ceph_inode_info *ci)
1792{
1793        loff_t size = ci->vfs_inode.i_size;
1794        /* mds will adjust max size according to the reported size */
1795        if (ci->i_flushing_caps & CEPH_CAP_FILE_WR)
1796                return false;
1797        if (size >= ci->i_max_size)
1798                return true;
1799        /* half of previous max_size increment has been used */
1800        if (ci->i_max_size > ci->i_reported_size &&
1801            (size << 1) >= ci->i_max_size + ci->i_reported_size)
1802                return true;
1803        return false;
1804}
1805
1806/*
1807 * Swiss army knife function to examine currently used and wanted
1808 * versus held caps.  Release, flush, ack revoked caps to mds as
1809 * appropriate.
1810 *
1811 *  CHECK_CAPS_NODELAY - caller is delayed work and we should not delay
1812 *    cap release further.
1813 *  CHECK_CAPS_AUTHONLY - we should only check the auth cap
1814 *  CHECK_CAPS_FLUSH - we should flush any dirty caps immediately, without
1815 *    further delay.
1816 */
1817void ceph_check_caps(struct ceph_inode_info *ci, int flags,
1818                     struct ceph_mds_session *session)
1819{
1820        struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1821        struct ceph_mds_client *mdsc = fsc->mdsc;
1822        struct inode *inode = &ci->vfs_inode;
1823        struct ceph_cap *cap;
1824        u64 flush_tid, oldest_flush_tid;
1825        int file_wanted, used, cap_used;
1826        int took_snap_rwsem = 0;             /* true if mdsc->snap_rwsem held */
1827        int issued, implemented, want, retain, revoking, flushing = 0;
1828        int mds = -1;   /* keep track of how far we've gone through i_caps list
1829                           to avoid an infinite loop on retry */
1830        struct rb_node *p;
1831        int delayed = 0, sent = 0;
1832        bool no_delay = flags & CHECK_CAPS_NODELAY;
1833        bool queue_invalidate = false;
1834        bool tried_invalidate = false;
1835
1836        /* if we are unmounting, flush any unused caps immediately. */
1837        if (mdsc->stopping)
1838                no_delay = true;
1839
1840        spin_lock(&ci->i_ceph_lock);
1841
1842        if (ci->i_ceph_flags & CEPH_I_FLUSH)
1843                flags |= CHECK_CAPS_FLUSH;
1844
1845        if (!(flags & CHECK_CAPS_AUTHONLY) ||
1846            (ci->i_auth_cap && __ceph_is_single_caps(ci)))
1847                __cap_delay_cancel(mdsc, ci);
1848
1849        goto retry_locked;
1850retry:
1851        spin_lock(&ci->i_ceph_lock);
1852retry_locked:
1853        file_wanted = __ceph_caps_file_wanted(ci);
1854        used = __ceph_caps_used(ci);
1855        issued = __ceph_caps_issued(ci, &implemented);
1856        revoking = implemented & ~issued;
1857
1858        want = file_wanted;
1859        retain = file_wanted | used | CEPH_CAP_PIN;
1860        if (!mdsc->stopping && inode->i_nlink > 0) {
1861                if (file_wanted) {
1862                        retain |= CEPH_CAP_ANY;       /* be greedy */
1863                } else if (S_ISDIR(inode->i_mode) &&
1864                           (issued & CEPH_CAP_FILE_SHARED) &&
1865                           __ceph_dir_is_complete(ci)) {
1866                        /*
1867                         * If a directory is complete, we want to keep
1868                         * the exclusive cap. So that MDS does not end up
1869                         * revoking the shared cap on every create/unlink
1870                         * operation.
1871                         */
1872                        if (IS_RDONLY(inode))
1873                                want = CEPH_CAP_ANY_SHARED;
1874                        else
1875                                want = CEPH_CAP_ANY_SHARED | CEPH_CAP_FILE_EXCL;
1876                        retain |= want;
1877                } else {
1878
1879                        retain |= CEPH_CAP_ANY_SHARED;
1880                        /*
1881                         * keep RD only if we didn't have the file open RW,
1882                         * because then the mds would revoke it anyway to
1883                         * journal max_size=0.
1884                         */
1885                        if (ci->i_max_size == 0)
1886                                retain |= CEPH_CAP_ANY_RD;
1887                }
1888        }
1889
1890        dout("check_caps %p file_want %s used %s dirty %s flushing %s"
1891             " issued %s revoking %s retain %s %s%s%s\n", inode,
1892             ceph_cap_string(file_wanted),
1893             ceph_cap_string(used), ceph_cap_string(ci->i_dirty_caps),
1894             ceph_cap_string(ci->i_flushing_caps),
1895             ceph_cap_string(issued), ceph_cap_string(revoking),
1896             ceph_cap_string(retain),
1897             (flags & CHECK_CAPS_AUTHONLY) ? " AUTHONLY" : "",
1898             (flags & CHECK_CAPS_NODELAY) ? " NODELAY" : "",
1899             (flags & CHECK_CAPS_FLUSH) ? " FLUSH" : "");
1900
1901        /*
1902         * If we no longer need to hold onto old our caps, and we may
1903         * have cached pages, but don't want them, then try to invalidate.
1904         * If we fail, it's because pages are locked.... try again later.
1905         */
1906        if ((!no_delay || mdsc->stopping) &&
1907            !S_ISDIR(inode->i_mode) &&          /* ignore readdir cache */
1908            !(ci->i_wb_ref || ci->i_wrbuffer_ref) &&   /* no dirty pages... */
1909            inode->i_data.nrpages &&            /* have cached pages */
1910            (revoking & (CEPH_CAP_FILE_CACHE|
1911                         CEPH_CAP_FILE_LAZYIO)) && /*  or revoking cache */
1912            !tried_invalidate) {
1913                dout("check_caps trying to invalidate on %p\n", inode);
1914                if (try_nonblocking_invalidate(inode) < 0) {
1915                        dout("check_caps queuing invalidate\n");
1916                        queue_invalidate = true;
1917                        ci->i_rdcache_revoking = ci->i_rdcache_gen;
1918                }
1919                tried_invalidate = true;
1920                goto retry_locked;
1921        }
1922
1923        for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
1924                cap = rb_entry(p, struct ceph_cap, ci_node);
1925
1926                /* avoid looping forever */
1927                if (mds >= cap->mds ||
1928                    ((flags & CHECK_CAPS_AUTHONLY) && cap != ci->i_auth_cap))
1929                        continue;
1930
1931                /* NOTE: no side-effects allowed, until we take s_mutex */
1932
1933                cap_used = used;
1934                if (ci->i_auth_cap && cap != ci->i_auth_cap)
1935                        cap_used &= ~ci->i_auth_cap->issued;
1936
1937                revoking = cap->implemented & ~cap->issued;
1938                dout(" mds%d cap %p used %s issued %s implemented %s revoking %s\n",
1939                     cap->mds, cap, ceph_cap_string(cap_used),
1940                     ceph_cap_string(cap->issued),
1941                     ceph_cap_string(cap->implemented),
1942                     ceph_cap_string(revoking));
1943
1944                if (cap == ci->i_auth_cap &&
1945                    (cap->issued & CEPH_CAP_FILE_WR)) {
1946                        /* request larger max_size from MDS? */
1947                        if (ci->i_wanted_max_size > ci->i_max_size &&
1948                            ci->i_wanted_max_size > ci->i_requested_max_size) {
1949                                dout("requesting new max_size\n");
1950                                goto ack;
1951                        }
1952
1953                        /* approaching file_max? */
1954                        if (__ceph_should_report_size(ci)) {
1955                                dout("i_size approaching max_size\n");
1956                                goto ack;
1957                        }
1958                }
1959                /* flush anything dirty? */
1960                if (cap == ci->i_auth_cap) {
1961                        if ((flags & CHECK_CAPS_FLUSH) && ci->i_dirty_caps) {
1962                                dout("flushing dirty caps\n");
1963                                goto ack;
1964                        }
1965                        if (ci->i_ceph_flags & CEPH_I_FLUSH_SNAPS) {
1966                                dout("flushing snap caps\n");
1967                                goto ack;
1968                        }
1969                }
1970
1971                /* completed revocation? going down and there are no caps? */
1972                if (revoking && (revoking & cap_used) == 0) {
1973                        dout("completed revocation of %s\n",
1974                             ceph_cap_string(cap->implemented & ~cap->issued));
1975                        goto ack;
1976                }
1977
1978                /* want more caps from mds? */
1979                if (want & ~(cap->mds_wanted | cap->issued))
1980                        goto ack;
1981
1982                /* things we might delay */
1983                if ((cap->issued & ~retain) == 0)
1984                        continue;     /* nope, all good */
1985
1986                if (no_delay)
1987                        goto ack;
1988
1989                /* delay? */
1990                if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1991                    time_before(jiffies, ci->i_hold_caps_max)) {
1992                        dout(" delaying issued %s -> %s, wanted %s -> %s\n",
1993                             ceph_cap_string(cap->issued),
1994                             ceph_cap_string(cap->issued & retain),
1995                             ceph_cap_string(cap->mds_wanted),
1996                             ceph_cap_string(want));
1997                        delayed++;
1998                        continue;
1999                }
2000
2001ack:
2002                if (session && session != cap->session) {
2003                        dout("oops, wrong session %p mutex\n", session);
2004                        mutex_unlock(&session->s_mutex);
2005                        session = NULL;
2006                }
2007                if (!session) {
2008                        session = cap->session;
2009                        if (mutex_trylock(&session->s_mutex) == 0) {
2010                                dout("inverting session/ino locks on %p\n",
2011                                     session);
2012                                spin_unlock(&ci->i_ceph_lock);
2013                                if (took_snap_rwsem) {
2014                                        up_read(&mdsc->snap_rwsem);
2015                                        took_snap_rwsem = 0;
2016                                }
2017                                mutex_lock(&session->s_mutex);
2018                                goto retry;
2019                        }
2020                }
2021
2022                /* kick flushing and flush snaps before sending normal
2023                 * cap message */
2024                if (cap == ci->i_auth_cap &&
2025                    (ci->i_ceph_flags &
2026                     (CEPH_I_KICK_FLUSH | CEPH_I_FLUSH_SNAPS))) {
2027                        if (ci->i_ceph_flags & CEPH_I_KICK_FLUSH)
2028                                __kick_flushing_caps(mdsc, session, ci, 0);
2029                        if (ci->i_ceph_flags & CEPH_I_FLUSH_SNAPS)
2030                                __ceph_flush_snaps(ci, session);
2031
2032                        goto retry_locked;
2033                }
2034
2035                /* take snap_rwsem after session mutex */
2036                if (!took_snap_rwsem) {
2037                        if (down_read_trylock(&mdsc->snap_rwsem) == 0) {
2038                                dout("inverting snap/in locks on %p\n",
2039                                     inode);
2040                                spin_unlock(&ci->i_ceph_lock);
2041                                down_read(&mdsc->snap_rwsem);
2042                                took_snap_rwsem = 1;
2043                                goto retry;
2044                        }
2045                        took_snap_rwsem = 1;
2046                }
2047
2048                if (cap == ci->i_auth_cap && ci->i_dirty_caps) {
2049                        flushing = ci->i_dirty_caps;
2050                        flush_tid = __mark_caps_flushing(inode, session, false,
2051                                                         &oldest_flush_tid);
2052                } else {
2053                        flushing = 0;
2054                        flush_tid = 0;
2055                        spin_lock(&mdsc->cap_dirty_lock);
2056                        oldest_flush_tid = __get_oldest_flush_tid(mdsc);
2057                        spin_unlock(&mdsc->cap_dirty_lock);
2058                }
2059
2060                mds = cap->mds;  /* remember mds, so we don't repeat */
2061                sent++;
2062
2063                /* __send_cap drops i_ceph_lock */
2064                delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, 0,
2065                                cap_used, want, retain, flushing,
2066                                flush_tid, oldest_flush_tid);
2067                goto retry; /* retake i_ceph_lock and restart our cap scan. */
2068        }
2069
2070        /* Reschedule delayed caps release if we delayed anything */
2071        if (delayed)
2072                __cap_delay_requeue(mdsc, ci, false);
2073
2074        spin_unlock(&ci->i_ceph_lock);
2075
2076        if (queue_invalidate)
2077                ceph_queue_invalidate(inode);
2078
2079        if (session)
2080                mutex_unlock(&session->s_mutex);
2081        if (took_snap_rwsem)
2082                up_read(&mdsc->snap_rwsem);
2083}
2084
2085/*
2086 * Try to flush dirty caps back to the auth mds.
2087 */
2088static int try_flush_caps(struct inode *inode, u64 *ptid)
2089{
2090        struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
2091        struct ceph_inode_info *ci = ceph_inode(inode);
2092        struct ceph_mds_session *session = NULL;
2093        int flushing = 0;
2094        u64 flush_tid = 0, oldest_flush_tid = 0;
2095
2096retry:
2097        spin_lock(&ci->i_ceph_lock);
2098retry_locked:
2099        if (ci->i_dirty_caps && ci->i_auth_cap) {
2100                struct ceph_cap *cap = ci->i_auth_cap;
2101                int delayed;
2102
2103                if (session != cap->session) {
2104                        spin_unlock(&ci->i_ceph_lock);
2105                        if (session)
2106                                mutex_unlock(&session->s_mutex);
2107                        session = cap->session;
2108                        mutex_lock(&session->s_mutex);
2109                        goto retry;
2110                }
2111                if (cap->session->s_state < CEPH_MDS_SESSION_OPEN) {
2112                        spin_unlock(&ci->i_ceph_lock);
2113                        goto out;
2114                }
2115
2116                if (ci->i_ceph_flags &
2117                    (CEPH_I_KICK_FLUSH | CEPH_I_FLUSH_SNAPS)) {
2118                        if (ci->i_ceph_flags & CEPH_I_KICK_FLUSH)
2119                                __kick_flushing_caps(mdsc, session, ci, 0);
2120                        if (ci->i_ceph_flags & CEPH_I_FLUSH_SNAPS)
2121                                __ceph_flush_snaps(ci, session);
2122                        goto retry_locked;
2123                }
2124
2125                flushing = ci->i_dirty_caps;
2126                flush_tid = __mark_caps_flushing(inode, session, true,
2127                                                 &oldest_flush_tid);
2128
2129                /* __send_cap drops i_ceph_lock */
2130                delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH,
2131                                     CEPH_CLIENT_CAPS_SYNC,
2132                                     __ceph_caps_used(ci),
2133                                     __ceph_caps_wanted(ci),
2134                                     (cap->issued | cap->implemented),
2135                                     flushing, flush_tid, oldest_flush_tid);
2136
2137                if (delayed) {
2138                        spin_lock(&ci->i_ceph_lock);
2139                        __cap_delay_requeue(mdsc, ci, true);
2140                        spin_unlock(&ci->i_ceph_lock);
2141                }
2142        } else {
2143                if (!list_empty(&ci->i_cap_flush_list)) {
2144                        struct ceph_cap_flush *cf =
2145                                list_last_entry(&ci->i_cap_flush_list,
2146                                                struct ceph_cap_flush, i_list);
2147                        cf->wake = true;
2148                        flush_tid = cf->tid;
2149                }
2150                flushing = ci->i_flushing_caps;
2151                spin_unlock(&ci->i_ceph_lock);
2152        }
2153out:
2154        if (session)
2155                mutex_unlock(&session->s_mutex);
2156
2157        *ptid = flush_tid;
2158        return flushing;
2159}
2160
2161/*
2162 * Return true if we've flushed caps through the given flush_tid.
2163 */
2164static int caps_are_flushed(struct inode *inode, u64 flush_tid)
2165{
2166        struct ceph_inode_info *ci = ceph_inode(inode);
2167        int ret = 1;
2168
2169        spin_lock(&ci->i_ceph_lock);
2170        if (!list_empty(&ci->i_cap_flush_list)) {
2171                struct ceph_cap_flush * cf =
2172                        list_first_entry(&ci->i_cap_flush_list,
2173                                         struct ceph_cap_flush, i_list);
2174                if (cf->tid <= flush_tid)
2175                        ret = 0;
2176        }
2177        spin_unlock(&ci->i_ceph_lock);
2178        return ret;
2179}
2180
2181/*
2182 * wait for any unsafe requests to complete.
2183 */
2184static int unsafe_request_wait(struct inode *inode)
2185{
2186        struct ceph_inode_info *ci = ceph_inode(inode);
2187        struct ceph_mds_request *req1 = NULL, *req2 = NULL;
2188        int ret, err = 0;
2189
2190        spin_lock(&ci->i_unsafe_lock);
2191        if (S_ISDIR(inode->i_mode) && !list_empty(&ci->i_unsafe_dirops)) {
2192                req1 = list_last_entry(&ci->i_unsafe_dirops,
2193                                        struct ceph_mds_request,
2194                                        r_unsafe_dir_item);
2195                ceph_mdsc_get_request(req1);
2196        }
2197        if (!list_empty(&ci->i_unsafe_iops)) {
2198                req2 = list_last_entry(&ci->i_unsafe_iops,
2199                                        struct ceph_mds_request,
2200                                        r_unsafe_target_item);
2201                ceph_mdsc_get_request(req2);
2202        }
2203        spin_unlock(&ci->i_unsafe_lock);
2204
2205        dout("unsafe_request_wait %p wait on tid %llu %llu\n",
2206             inode, req1 ? req1->r_tid : 0ULL, req2 ? req2->r_tid : 0ULL);
2207        if (req1) {
2208                ret = !wait_for_completion_timeout(&req1->r_safe_completion,
2209                                        ceph_timeout_jiffies(req1->r_timeout));
2210                if (ret)
2211                        err = -EIO;
2212                ceph_mdsc_put_request(req1);
2213        }
2214        if (req2) {
2215                ret = !wait_for_completion_timeout(&req2->r_safe_completion,
2216                                        ceph_timeout_jiffies(req2->r_timeout));
2217                if (ret)
2218                        err = -EIO;
2219                ceph_mdsc_put_request(req2);
2220        }
2221        return err;
2222}
2223
2224int ceph_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2225{
2226        struct ceph_file_info *fi = file->private_data;
2227        struct inode *inode = file->f_mapping->host;
2228        struct ceph_inode_info *ci = ceph_inode(inode);
2229        u64 flush_tid;
2230        int ret, err;
2231        int dirty;
2232
2233        dout("fsync %p%s\n", inode, datasync ? " datasync" : "");
2234
2235        ret = file_write_and_wait_range(file, start, end);
2236        if (datasync)
2237                goto out;
2238
2239        dirty = try_flush_caps(inode, &flush_tid);
2240        dout("fsync dirty caps are %s\n", ceph_cap_string(dirty));
2241
2242        err = unsafe_request_wait(inode);
2243
2244        /*
2245         * only wait on non-file metadata writeback (the mds
2246         * can recover size and mtime, so we don't need to
2247         * wait for that)
2248         */
2249        if (!err && (dirty & ~CEPH_CAP_ANY_FILE_WR)) {
2250                err = wait_event_interruptible(ci->i_cap_wq,
2251                                        caps_are_flushed(inode, flush_tid));
2252        }
2253
2254        if (err < 0)
2255                ret = err;
2256
2257        if (errseq_check(&ci->i_meta_err, READ_ONCE(fi->meta_err))) {
2258                spin_lock(&file->f_lock);
2259                err = errseq_check_and_advance(&ci->i_meta_err,
2260                                               &fi->meta_err);
2261                spin_unlock(&file->f_lock);
2262                if (err < 0)
2263                        ret = err;
2264        }
2265out:
2266        dout("fsync %p%s result=%d\n", inode, datasync ? " datasync" : "", ret);
2267        return ret;
2268}
2269
2270/*
2271 * Flush any dirty caps back to the mds.  If we aren't asked to wait,
2272 * queue inode for flush but don't do so immediately, because we can
2273 * get by with fewer MDS messages if we wait for data writeback to
2274 * complete first.
2275 */
2276int ceph_write_inode(struct inode *inode, struct writeback_control *wbc)
2277{
2278        struct ceph_inode_info *ci = ceph_inode(inode);
2279        u64 flush_tid;
2280        int err = 0;
2281        int dirty;
2282        int wait = (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync);
2283
2284        dout("write_inode %p wait=%d\n", inode, wait);
2285        if (wait) {
2286                dirty = try_flush_caps(inode, &flush_tid);
2287                if (dirty)
2288                        err = wait_event_interruptible(ci->i_cap_wq,
2289                                       caps_are_flushed(inode, flush_tid));
2290        } else {
2291                struct ceph_mds_client *mdsc =
2292                        ceph_sb_to_client(inode->i_sb)->mdsc;
2293
2294                spin_lock(&ci->i_ceph_lock);
2295                if (__ceph_caps_dirty(ci))
2296                        __cap_delay_requeue_front(mdsc, ci);
2297                spin_unlock(&ci->i_ceph_lock);
2298        }
2299        return err;
2300}
2301
2302static void __kick_flushing_caps(struct ceph_mds_client *mdsc,
2303                                 struct ceph_mds_session *session,
2304                                 struct ceph_inode_info *ci,
2305                                 u64 oldest_flush_tid)
2306        __releases(ci->i_ceph_lock)
2307        __acquires(ci->i_ceph_lock)
2308{
2309        struct inode *inode = &ci->vfs_inode;
2310        struct ceph_cap *cap;
2311        struct ceph_cap_flush *cf;
2312        int ret;
2313        u64 first_tid = 0;
2314        u64 last_snap_flush = 0;
2315
2316        ci->i_ceph_flags &= ~CEPH_I_KICK_FLUSH;
2317
2318        list_for_each_entry_reverse(cf, &ci->i_cap_flush_list, i_list) {
2319                if (!cf->caps) {
2320                        last_snap_flush = cf->tid;
2321                        break;
2322                }
2323        }
2324
2325        list_for_each_entry(cf, &ci->i_cap_flush_list, i_list) {
2326                if (cf->tid < first_tid)
2327                        continue;
2328
2329                cap = ci->i_auth_cap;
2330                if (!(cap && cap->session == session)) {
2331                        pr_err("%p auth cap %p not mds%d ???\n",
2332                               inode, cap, session->s_mds);
2333                        break;
2334                }
2335
2336                first_tid = cf->tid + 1;
2337
2338                if (cf->caps) {
2339                        dout("kick_flushing_caps %p cap %p tid %llu %s\n",
2340                             inode, cap, cf->tid, ceph_cap_string(cf->caps));
2341                        ci->i_ceph_flags |= CEPH_I_NODELAY;
2342
2343                        ret = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH,
2344                                         (cf->tid < last_snap_flush ?
2345                                          CEPH_CLIENT_CAPS_PENDING_CAPSNAP : 0),
2346                                          __ceph_caps_used(ci),
2347                                          __ceph_caps_wanted(ci),
2348                                          (cap->issued | cap->implemented),
2349                                          cf->caps, cf->tid, oldest_flush_tid);
2350                        if (ret) {
2351                                pr_err("kick_flushing_caps: error sending "
2352                                        "cap flush, ino (%llx.%llx) "
2353                                        "tid %llu flushing %s\n",
2354                                        ceph_vinop(inode), cf->tid,
2355                                        ceph_cap_string(cf->caps));
2356                        }
2357                } else {
2358                        struct ceph_cap_snap *capsnap =
2359                                        container_of(cf, struct ceph_cap_snap,
2360                                                    cap_flush);
2361                        dout("kick_flushing_caps %p capsnap %p tid %llu %s\n",
2362                             inode, capsnap, cf->tid,
2363                             ceph_cap_string(capsnap->dirty));
2364
2365                        refcount_inc(&capsnap->nref);
2366                        spin_unlock(&ci->i_ceph_lock);
2367
2368                        ret = __send_flush_snap(inode, session, capsnap, cap->mseq,
2369                                                oldest_flush_tid);
2370                        if (ret < 0) {
2371                                pr_err("kick_flushing_caps: error sending "
2372                                        "cap flushsnap, ino (%llx.%llx) "
2373                                        "tid %llu follows %llu\n",
2374                                        ceph_vinop(inode), cf->tid,
2375                                        capsnap->follows);
2376                        }
2377
2378                        ceph_put_cap_snap(capsnap);
2379                }
2380
2381                spin_lock(&ci->i_ceph_lock);
2382        }
2383}
2384
2385void ceph_early_kick_flushing_caps(struct ceph_mds_client *mdsc,
2386                                   struct ceph_mds_session *session)
2387{
2388        struct ceph_inode_info *ci;
2389        struct ceph_cap *cap;
2390        u64 oldest_flush_tid;
2391
2392        dout("early_kick_flushing_caps mds%d\n", session->s_mds);
2393
2394        spin_lock(&mdsc->cap_dirty_lock);
2395        oldest_flush_tid = __get_oldest_flush_tid(mdsc);
2396        spin_unlock(&mdsc->cap_dirty_lock);
2397
2398        list_for_each_entry(ci, &session->s_cap_flushing, i_flushing_item) {
2399                spin_lock(&ci->i_ceph_lock);
2400                cap = ci->i_auth_cap;
2401                if (!(cap && cap->session == session)) {
2402                        pr_err("%p auth cap %p not mds%d ???\n",
2403                                &ci->vfs_inode, cap, session->s_mds);
2404                        spin_unlock(&ci->i_ceph_lock);
2405                        continue;
2406                }
2407
2408
2409                /*
2410                 * if flushing caps were revoked, we re-send the cap flush
2411                 * in client reconnect stage. This guarantees MDS * processes
2412                 * the cap flush message before issuing the flushing caps to
2413                 * other client.
2414                 */
2415                if ((cap->issued & ci->i_flushing_caps) !=
2416                    ci->i_flushing_caps) {
2417                        /* encode_caps_cb() also will reset these sequence
2418                         * numbers. make sure sequence numbers in cap flush
2419                         * message match later reconnect message */
2420                        cap->seq = 0;
2421                        cap->issue_seq = 0;
2422                        cap->mseq = 0;
2423                        __kick_flushing_caps(mdsc, session, ci,
2424                                             oldest_flush_tid);
2425                } else {
2426                        ci->i_ceph_flags |= CEPH_I_KICK_FLUSH;
2427                }
2428
2429                spin_unlock(&ci->i_ceph_lock);
2430        }
2431}
2432
2433void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
2434                             struct ceph_mds_session *session)
2435{
2436        struct ceph_inode_info *ci;
2437        struct ceph_cap *cap;
2438        u64 oldest_flush_tid;
2439
2440        dout("kick_flushing_caps mds%d\n", session->s_mds);
2441
2442        spin_lock(&mdsc->cap_dirty_lock);
2443        oldest_flush_tid = __get_oldest_flush_tid(mdsc);
2444        spin_unlock(&mdsc->cap_dirty_lock);
2445
2446        list_for_each_entry(ci, &session->s_cap_flushing, i_flushing_item) {
2447                spin_lock(&ci->i_ceph_lock);
2448                cap = ci->i_auth_cap;
2449                if (!(cap && cap->session == session)) {
2450                        pr_err("%p auth cap %p not mds%d ???\n",
2451                                &ci->vfs_inode, cap, session->s_mds);
2452                        spin_unlock(&ci->i_ceph_lock);
2453                        continue;
2454                }
2455                if (ci->i_ceph_flags & CEPH_I_KICK_FLUSH) {
2456                        __kick_flushing_caps(mdsc, session, ci,
2457                                             oldest_flush_tid);
2458                }
2459                spin_unlock(&ci->i_ceph_lock);
2460        }
2461}
2462
2463static void kick_flushing_inode_caps(struct ceph_mds_client *mdsc,
2464                                     struct ceph_mds_session *session,
2465                                     struct inode *inode)
2466        __releases(ci->i_ceph_lock)
2467{
2468        struct ceph_inode_info *ci = ceph_inode(inode);
2469        struct ceph_cap *cap;
2470
2471        cap = ci->i_auth_cap;
2472        dout("kick_flushing_inode_caps %p flushing %s\n", inode,
2473             ceph_cap_string(ci->i_flushing_caps));
2474
2475        if (!list_empty(&ci->i_cap_flush_list)) {
2476                u64 oldest_flush_tid;
2477                spin_lock(&mdsc->cap_dirty_lock);
2478                list_move_tail(&ci->i_flushing_item,
2479                               &cap->session->s_cap_flushing);
2480                oldest_flush_tid = __get_oldest_flush_tid(mdsc);
2481                spin_unlock(&mdsc->cap_dirty_lock);
2482
2483                __kick_flushing_caps(mdsc, session, ci, oldest_flush_tid);
2484                spin_unlock(&ci->i_ceph_lock);
2485        } else {
2486                spin_unlock(&ci->i_ceph_lock);
2487        }
2488}
2489
2490
2491/*
2492 * Take references to capabilities we hold, so that we don't release
2493 * them to the MDS prematurely.
2494 *
2495 * Protected by i_ceph_lock.
2496 */
2497static void __take_cap_refs(struct ceph_inode_info *ci, int got,
2498                            bool snap_rwsem_locked)
2499{
2500        if (got & CEPH_CAP_PIN)
2501                ci->i_pin_ref++;
2502        if (got & CEPH_CAP_FILE_RD)
2503                ci->i_rd_ref++;
2504        if (got & CEPH_CAP_FILE_CACHE)
2505                ci->i_rdcache_ref++;
2506        if (got & CEPH_CAP_FILE_WR) {
2507                if (ci->i_wr_ref == 0 && !ci->i_head_snapc) {
2508                        BUG_ON(!snap_rwsem_locked);
2509                        ci->i_head_snapc = ceph_get_snap_context(
2510                                        ci->i_snap_realm->cached_context);
2511                }
2512                ci->i_wr_ref++;
2513        }
2514        if (got & CEPH_CAP_FILE_BUFFER) {
2515                if (ci->i_wb_ref == 0)
2516                        ihold(&ci->vfs_inode);
2517                ci->i_wb_ref++;
2518                dout("__take_cap_refs %p wb %d -> %d (?)\n",
2519                     &ci->vfs_inode, ci->i_wb_ref-1, ci->i_wb_ref);
2520        }
2521}
2522
2523/*
2524 * Try to grab cap references.  Specify those refs we @want, and the
2525 * minimal set we @need.  Also include the larger offset we are writing
2526 * to (when applicable), and check against max_size here as well.
2527 * Note that caller is responsible for ensuring max_size increases are
2528 * requested from the MDS.
2529 *
2530 * Returns 0 if caps were not able to be acquired (yet), a 1 if they were,
2531 * or a negative error code.
2532 *
2533 * FIXME: how does a 0 return differ from -EAGAIN?
2534 */
2535enum {
2536        NON_BLOCKING    = 1,
2537        CHECK_FILELOCK  = 2,
2538};
2539
2540static int try_get_cap_refs(struct inode *inode, int need, int want,
2541                            loff_t endoff, int flags, int *got)
2542{
2543        struct ceph_inode_info *ci = ceph_inode(inode);
2544        struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
2545        int ret = 0;
2546        int have, implemented;
2547        int file_wanted;
2548        bool snap_rwsem_locked = false;
2549
2550        dout("get_cap_refs %p need %s want %s\n", inode,
2551             ceph_cap_string(need), ceph_cap_string(want));
2552
2553again:
2554        spin_lock(&ci->i_ceph_lock);
2555
2556        if ((flags & CHECK_FILELOCK) &&
2557            (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK)) {
2558                dout("try_get_cap_refs %p error filelock\n", inode);
2559                ret = -EIO;
2560                goto out_unlock;
2561        }
2562
2563        /* make sure file is actually open */
2564        file_wanted = __ceph_caps_file_wanted(ci);
2565        if ((file_wanted & need) != need) {
2566                dout("try_get_cap_refs need %s file_wanted %s, EBADF\n",
2567                     ceph_cap_string(need), ceph_cap_string(file_wanted));
2568                ret = -EBADF;
2569                goto out_unlock;
2570        }
2571
2572        /* finish pending truncate */
2573        while (ci->i_truncate_pending) {
2574                spin_unlock(&ci->i_ceph_lock);
2575                if (snap_rwsem_locked) {
2576                        up_read(&mdsc->snap_rwsem);
2577                        snap_rwsem_locked = false;
2578                }
2579                __ceph_do_pending_vmtruncate(inode);
2580                spin_lock(&ci->i_ceph_lock);
2581        }
2582
2583        have = __ceph_caps_issued(ci, &implemented);
2584
2585        if (have & need & CEPH_CAP_FILE_WR) {
2586                if (endoff >= 0 && endoff > (loff_t)ci->i_max_size) {
2587                        dout("get_cap_refs %p endoff %llu > maxsize %llu\n",
2588                             inode, endoff, ci->i_max_size);
2589                        if (endoff > ci->i_requested_max_size)
2590                                ret = -EAGAIN;
2591                        goto out_unlock;
2592                }
2593                /*
2594                 * If a sync write is in progress, we must wait, so that we
2595                 * can get a final snapshot value for size+mtime.
2596                 */
2597                if (__ceph_have_pending_cap_snap(ci)) {
2598                        dout("get_cap_refs %p cap_snap_pending\n", inode);
2599                        goto out_unlock;
2600                }
2601        }
2602
2603        if ((have & need) == need) {
2604                /*
2605                 * Look at (implemented & ~have & not) so that we keep waiting
2606                 * on transition from wanted -> needed caps.  This is needed
2607                 * for WRBUFFER|WR -> WR to avoid a new WR sync write from
2608                 * going before a prior buffered writeback happens.
2609                 */
2610                int not = want & ~(have & need);
2611                int revoking = implemented & ~have;
2612                dout("get_cap_refs %p have %s but not %s (revoking %s)\n",
2613                     inode, ceph_cap_string(have), ceph_cap_string(not),
2614                     ceph_cap_string(revoking));
2615                if ((revoking & not) == 0) {
2616                        if (!snap_rwsem_locked &&
2617                            !ci->i_head_snapc &&
2618                            (need & CEPH_CAP_FILE_WR)) {
2619                                if (!down_read_trylock(&mdsc->snap_rwsem)) {
2620                                        /*
2621                                         * we can not call down_read() when
2622                                         * task isn't in TASK_RUNNING state
2623                                         */
2624                                        if (flags & NON_BLOCKING) {
2625                                                ret = -EAGAIN;
2626                                                goto out_unlock;
2627                                        }
2628
2629                                        spin_unlock(&ci->i_ceph_lock);
2630                                        down_read(&mdsc->snap_rwsem);
2631                                        snap_rwsem_locked = true;
2632                                        goto again;
2633                                }
2634                                snap_rwsem_locked = true;
2635                        }
2636                        *got = need | (have & want);
2637                        if ((need & CEPH_CAP_FILE_RD) &&
2638                            !(*got & CEPH_CAP_FILE_CACHE))
2639                                ceph_disable_fscache_readpage(ci);
2640                        __take_cap_refs(ci, *got, true);
2641                        ret = 1;
2642                }
2643        } else {
2644                int session_readonly = false;
2645                if ((need & CEPH_CAP_FILE_WR) && ci->i_auth_cap) {
2646                        struct ceph_mds_session *s = ci->i_auth_cap->session;
2647                        spin_lock(&s->s_cap_lock);
2648                        session_readonly = s->s_readonly;
2649                        spin_unlock(&s->s_cap_lock);
2650                }
2651                if (session_readonly) {
2652                        dout("get_cap_refs %p needed %s but mds%d readonly\n",
2653                             inode, ceph_cap_string(need), ci->i_auth_cap->mds);
2654                        ret = -EROFS;
2655                        goto out_unlock;
2656                }
2657
2658                if (ci->i_ceph_flags & CEPH_I_CAP_DROPPED) {
2659                        int mds_wanted;
2660                        if (READ_ONCE(mdsc->fsc->mount_state) ==
2661                            CEPH_MOUNT_SHUTDOWN) {
2662                                dout("get_cap_refs %p forced umount\n", inode);
2663                                ret = -EIO;
2664                                goto out_unlock;
2665                        }
2666                        mds_wanted = __ceph_caps_mds_wanted(ci, false);
2667                        if (need & ~(mds_wanted & need)) {
2668                                dout("get_cap_refs %p caps were dropped"
2669                                     " (session killed?)\n", inode);
2670                                ret = -ESTALE;
2671                                goto out_unlock;
2672                        }
2673                        if (!(file_wanted & ~mds_wanted))
2674                                ci->i_ceph_flags &= ~CEPH_I_CAP_DROPPED;
2675                }
2676
2677                dout("get_cap_refs %p have %s needed %s\n", inode,
2678                     ceph_cap_string(have), ceph_cap_string(need));
2679        }
2680out_unlock:
2681        spin_unlock(&ci->i_ceph_lock);
2682        if (snap_rwsem_locked)
2683                up_read(&mdsc->snap_rwsem);
2684
2685        dout("get_cap_refs %p ret %d got %s\n", inode,
2686             ret, ceph_cap_string(*got));
2687        return ret;
2688}
2689
2690/*
2691 * Check the offset we are writing up to against our current
2692 * max_size.  If necessary, tell the MDS we want to write to
2693 * a larger offset.
2694 */
2695static void check_max_size(struct inode *inode, loff_t endoff)
2696{
2697        struct ceph_inode_info *ci = ceph_inode(inode);
2698        int check = 0;
2699
2700        /* do we need to explicitly request a larger max_size? */
2701        spin_lock(&ci->i_ceph_lock);
2702        if (endoff >= ci->i_max_size && endoff > ci->i_wanted_max_size) {
2703                dout("write %p at large endoff %llu, req max_size\n",
2704                     inode, endoff);
2705                ci->i_wanted_max_size = endoff;
2706        }
2707        /* duplicate ceph_check_caps()'s logic */
2708        if (ci->i_auth_cap &&
2709            (ci->i_auth_cap->issued & CEPH_CAP_FILE_WR) &&
2710            ci->i_wanted_max_size > ci->i_max_size &&
2711            ci->i_wanted_max_size > ci->i_requested_max_size)
2712                check = 1;
2713        spin_unlock(&ci->i_ceph_lock);
2714        if (check)
2715                ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
2716}
2717
2718int ceph_try_get_caps(struct inode *inode, int need, int want,
2719                      bool nonblock, int *got)
2720{
2721        int ret;
2722
2723        BUG_ON(need & ~CEPH_CAP_FILE_RD);
2724        BUG_ON(want & ~(CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO|CEPH_CAP_FILE_SHARED));
2725        ret = ceph_pool_perm_check(inode, need);
2726        if (ret < 0)
2727                return ret;
2728
2729        ret = try_get_cap_refs(inode, need, want, 0,
2730                               (nonblock ? NON_BLOCKING : 0), got);
2731        return ret == -EAGAIN ? 0 : ret;
2732}
2733
2734/*
2735 * Wait for caps, and take cap references.  If we can't get a WR cap
2736 * due to a small max_size, make sure we check_max_size (and possibly
2737 * ask the mds) so we don't get hung up indefinitely.
2738 */
2739int ceph_get_caps(struct file *filp, int need, int want,
2740                  loff_t endoff, int *got, struct page **pinned_page)
2741{
2742        struct ceph_file_info *fi = filp->private_data;
2743        struct inode *inode = file_inode(filp);
2744        struct ceph_inode_info *ci = ceph_inode(inode);
2745        struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
2746        int ret, _got, flags;
2747
2748        ret = ceph_pool_perm_check(inode, need);
2749        if (ret < 0)
2750                return ret;
2751
2752        if ((fi->fmode & CEPH_FILE_MODE_WR) &&
2753            fi->filp_gen != READ_ONCE(fsc->filp_gen))
2754                return -EBADF;
2755
2756        while (true) {
2757                if (endoff > 0)
2758                        check_max_size(inode, endoff);
2759
2760                flags = atomic_read(&fi->num_locks) ? CHECK_FILELOCK : 0;
2761                _got = 0;
2762                ret = try_get_cap_refs(inode, need, want, endoff,
2763                                       flags, &_got);
2764                if (ret == -EAGAIN)
2765                        continue;
2766                if (!ret) {
2767                        DEFINE_WAIT_FUNC(wait, woken_wake_function);
2768                        add_wait_queue(&ci->i_cap_wq, &wait);
2769
2770                        flags |= NON_BLOCKING;
2771                        while (!(ret = try_get_cap_refs(inode, need, want,
2772                                                        endoff, flags, &_got))) {
2773                                if (signal_pending(current)) {
2774                                        ret = -ERESTARTSYS;
2775                                        break;
2776                                }
2777                                wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
2778                        }
2779
2780                        remove_wait_queue(&ci->i_cap_wq, &wait);
2781                        if (ret == -EAGAIN)
2782                                continue;
2783                }
2784
2785                if ((fi->fmode & CEPH_FILE_MODE_WR) &&
2786                    fi->filp_gen != READ_ONCE(fsc->filp_gen)) {
2787                        if (ret >= 0 && _got)
2788                                ceph_put_cap_refs(ci, _got);
2789                        return -EBADF;
2790                }
2791
2792                if (ret < 0) {
2793                        if (ret == -ESTALE) {
2794                                /* session was killed, try renew caps */
2795                                ret = ceph_renew_caps(inode);
2796                                if (ret == 0)
2797                                        continue;
2798                        }
2799                        return ret;
2800                }
2801
2802                if (ci->i_inline_version != CEPH_INLINE_NONE &&
2803                    (_got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
2804                    i_size_read(inode) > 0) {
2805                        struct page *page =
2806                                find_get_page(inode->i_mapping, 0);
2807                        if (page) {
2808                                if (PageUptodate(page)) {
2809                                        *pinned_page = page;
2810                                        break;
2811                                }
2812                                put_page(page);
2813                        }
2814                        /*
2815                         * drop cap refs first because getattr while
2816                         * holding * caps refs can cause deadlock.
2817                         */
2818                        ceph_put_cap_refs(ci, _got);
2819                        _got = 0;
2820
2821                        /*
2822                         * getattr request will bring inline data into
2823                         * page cache
2824                         */
2825                        ret = __ceph_do_getattr(inode, NULL,
2826                                                CEPH_STAT_CAP_INLINE_DATA,
2827                                                true);
2828                        if (ret < 0)
2829                                return ret;
2830                        continue;
2831                }
2832                break;
2833        }
2834
2835        if ((_got & CEPH_CAP_FILE_RD) && (_got & CEPH_CAP_FILE_CACHE))
2836                ceph_fscache_revalidate_cookie(ci);
2837
2838        *got = _got;
2839        return 0;
2840}
2841
2842/*
2843 * Take cap refs.  Caller must already know we hold at least one ref
2844 * on the caps in question or we don't know this is safe.
2845 */
2846void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps)
2847{
2848        spin_lock(&ci->i_ceph_lock);
2849        __take_cap_refs(ci, caps, false);
2850        spin_unlock(&ci->i_ceph_lock);
2851}
2852
2853
2854/*
2855 * drop cap_snap that is not associated with any snapshot.
2856 * we don't need to send FLUSHSNAP message for it.
2857 */
2858static int ceph_try_drop_cap_snap(struct ceph_inode_info *ci,
2859                                  struct ceph_cap_snap *capsnap)
2860{
2861        if (!capsnap->need_flush &&
2862            !capsnap->writing && !capsnap->dirty_pages) {
2863                dout("dropping cap_snap %p follows %llu\n",
2864                     capsnap, capsnap->follows);
2865                BUG_ON(capsnap->cap_flush.tid > 0);
2866                ceph_put_snap_context(capsnap->context);
2867                if (!list_is_last(&capsnap->ci_item, &ci->i_cap_snaps))
2868                        ci->i_ceph_flags |= CEPH_I_FLUSH_SNAPS;
2869
2870                list_del(&capsnap->ci_item);
2871                ceph_put_cap_snap(capsnap);
2872                return 1;
2873        }
2874        return 0;
2875}
2876
2877/*
2878 * Release cap refs.
2879 *
2880 * If we released the last ref on any given cap, call ceph_check_caps
2881 * to release (or schedule a release).
2882 *
2883 * If we are releasing a WR cap (from a sync write), finalize any affected
2884 * cap_snap, and wake up any waiters.
2885 */
2886void ceph_put_cap_refs(struct ceph_inode_info *ci, int had)
2887{
2888        struct inode *inode = &ci->vfs_inode;
2889        int last = 0, put = 0, flushsnaps = 0, wake = 0;
2890
2891        spin_lock(&ci->i_ceph_lock);
2892        if (had & CEPH_CAP_PIN)
2893                --ci->i_pin_ref;
2894        if (had & CEPH_CAP_FILE_RD)
2895                if (--ci->i_rd_ref == 0)
2896                        last++;
2897        if (had & CEPH_CAP_FILE_CACHE)
2898                if (--ci->i_rdcache_ref == 0)
2899                        last++;
2900        if (had & CEPH_CAP_FILE_BUFFER) {
2901                if (--ci->i_wb_ref == 0) {
2902                        last++;
2903                        put++;
2904                }
2905                dout("put_cap_refs %p wb %d -> %d (?)\n",
2906                     inode, ci->i_wb_ref+1, ci->i_wb_ref);
2907        }
2908        if (had & CEPH_CAP_FILE_WR)
2909                if (--ci->i_wr_ref == 0) {
2910                        last++;
2911                        if (__ceph_have_pending_cap_snap(ci)) {
2912                                struct ceph_cap_snap *capsnap =
2913                                        list_last_entry(&ci->i_cap_snaps,
2914                                                        struct ceph_cap_snap,
2915                                                        ci_item);
2916                                capsnap->writing = 0;
2917                                if (ceph_try_drop_cap_snap(ci, capsnap))
2918                                        put++;
2919                                else if (__ceph_finish_cap_snap(ci, capsnap))
2920                                        flushsnaps = 1;
2921                                wake = 1;
2922                        }
2923                        if (ci->i_wrbuffer_ref_head == 0 &&
2924                            ci->i_dirty_caps == 0 &&
2925                            ci->i_flushing_caps == 0) {
2926                                BUG_ON(!ci->i_head_snapc);
2927                                ceph_put_snap_context(ci->i_head_snapc);
2928                                ci->i_head_snapc = NULL;
2929                        }
2930                        /* see comment in __ceph_remove_cap() */
2931                        if (!__ceph_is_any_caps(ci) && ci->i_snap_realm)
2932                                drop_inode_snap_realm(ci);
2933                }
2934        spin_unlock(&ci->i_ceph_lock);
2935
2936        dout("put_cap_refs %p had %s%s%s\n", inode, ceph_cap_string(had),
2937             last ? " last" : "", put ? " put" : "");
2938
2939        if (last && !flushsnaps)
2940                ceph_check_caps(ci, 0, NULL);
2941        else if (flushsnaps)
2942                ceph_flush_snaps(ci, NULL);
2943        if (wake)
2944                wake_up_all(&ci->i_cap_wq);
2945        while (put-- > 0)
2946                iput(inode);
2947}
2948
2949/*
2950 * Release @nr WRBUFFER refs on dirty pages for the given @snapc snap
2951 * context.  Adjust per-snap dirty page accounting as appropriate.
2952 * Once all dirty data for a cap_snap is flushed, flush snapped file
2953 * metadata back to the MDS.  If we dropped the last ref, call
2954 * ceph_check_caps.
2955 */
2956void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
2957                                struct ceph_snap_context *snapc)
2958{
2959        struct inode *inode = &ci->vfs_inode;
2960        struct ceph_cap_snap *capsnap = NULL;
2961        int put = 0;
2962        bool last = false;
2963        bool found = false;
2964        bool flush_snaps = false;
2965        bool complete_capsnap = false;
2966
2967        spin_lock(&ci->i_ceph_lock);
2968        ci->i_wrbuffer_ref -= nr;
2969        if (ci->i_wrbuffer_ref == 0) {
2970                last = true;
2971                put++;
2972        }
2973
2974        if (ci->i_head_snapc == snapc) {
2975                ci->i_wrbuffer_ref_head -= nr;
2976                if (ci->i_wrbuffer_ref_head == 0 &&
2977                    ci->i_wr_ref == 0 &&
2978                    ci->i_dirty_caps == 0 &&
2979                    ci->i_flushing_caps == 0) {
2980                        BUG_ON(!ci->i_head_snapc);
2981                        ceph_put_snap_context(ci->i_head_snapc);
2982                        ci->i_head_snapc = NULL;
2983                }
2984                dout("put_wrbuffer_cap_refs on %p head %d/%d -> %d/%d %s\n",
2985                     inode,
2986                     ci->i_wrbuffer_ref+nr, ci->i_wrbuffer_ref_head+nr,
2987                     ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
2988                     last ? " LAST" : "");
2989        } else {
2990                list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
2991                        if (capsnap->context == snapc) {
2992                                found = true;
2993                                break;
2994                        }
2995                }
2996                BUG_ON(!found);
2997                capsnap->dirty_pages -= nr;
2998                if (capsnap->dirty_pages == 0) {
2999                        complete_capsnap = true;
3000                        if (!capsnap->writing) {
3001                                if (ceph_try_drop_cap_snap(ci, capsnap)) {
3002                                        put++;
3003                                } else {
3004                                        ci->i_ceph_flags |= CEPH_I_FLUSH_SNAPS;
3005                                        flush_snaps = true;
3006                                }
3007                        }
3008                }
3009                dout("put_wrbuffer_cap_refs on %p cap_snap %p "
3010                     " snap %lld %d/%d -> %d/%d %s%s\n",
3011                     inode, capsnap, capsnap->context->seq,
3012                     ci->i_wrbuffer_ref+nr, capsnap->dirty_pages + nr,
3013                     ci->i_wrbuffer_ref, capsnap->dirty_pages,
3014                     last ? " (wrbuffer last)" : "",
3015                     complete_capsnap ? " (complete capsnap)" : "");
3016        }
3017
3018        spin_unlock(&ci->i_ceph_lock);
3019
3020        if (last) {
3021                ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
3022        } else if (flush_snaps) {
3023                ceph_flush_snaps(ci, NULL);
3024        }
3025        if (complete_capsnap)
3026                wake_up_all(&ci->i_cap_wq);
3027        while (put-- > 0) {
3028                /* avoid calling iput_final() in osd dispatch threads */
3029                ceph_async_iput(inode);
3030        }
3031}
3032
3033/*
3034 * Invalidate unlinked inode's aliases, so we can drop the inode ASAP.
3035 */
3036static void invalidate_aliases(struct inode *inode)
3037{
3038        struct dentry *dn, *prev = NULL;
3039
3040        dout("invalidate_aliases inode %p\n", inode);
3041        d_prune_aliases(inode);
3042        /*
3043         * For non-directory inode, d_find_alias() only returns
3044         * hashed dentry. After calling d_invalidate(), the
3045         * dentry becomes unhashed.
3046         *
3047         * For directory inode, d_find_alias() can return
3048         * unhashed dentry. But directory inode should have
3049         * one alias at most.
3050         */
3051        while ((dn = d_find_alias(inode))) {
3052                if (dn == prev) {
3053                        dput(dn);
3054                        break;
3055                }
3056                d_invalidate(dn);
3057                if (prev)
3058                        dput(prev);
3059                prev = dn;
3060        }
3061        if (prev)
3062                dput(prev);
3063}
3064
3065struct cap_extra_info {
3066        struct ceph_string *pool_ns;
3067        /* inline data */
3068        u64 inline_version;
3069        void *inline_data;
3070        u32 inline_len;
3071        /* dirstat */
3072        bool dirstat_valid;
3073        u64 nfiles;
3074        u64 nsubdirs;
3075        u64 change_attr;
3076        /* currently issued */
3077        int issued;
3078        struct timespec64 btime;
3079};
3080
3081/*
3082 * Handle a cap GRANT message from the MDS.  (Note that a GRANT may
3083 * actually be a revocation if it specifies a smaller cap set.)
3084 *
3085 * caller holds s_mutex and i_ceph_lock, we drop both.
3086 */
3087static void handle_cap_grant(struct inode *inode,
3088                             struct ceph_mds_session *session,
3089                             struct ceph_cap *cap,
3090                             struct ceph_mds_caps *grant,
3091                             struct ceph_buffer *xattr_buf,
3092                             struct cap_extra_info *extra_info)
3093        __releases(ci->i_ceph_lock)
3094        __releases(session->s_mdsc->snap_rwsem)
3095{
3096        struct ceph_inode_info *ci = ceph_inode(inode);
3097        int seq = le32_to_cpu(grant->seq);
3098        int newcaps = le32_to_cpu(grant->caps);
3099        int used, wanted, dirty;
3100        u64 size = le64_to_cpu(grant->size);
3101        u64 max_size = le64_to_cpu(grant->max_size);
3102        unsigned char check_caps = 0;
3103        bool was_stale = cap->cap_gen < session->s_cap_gen;
3104        bool wake = false;
3105        bool writeback = false;
3106        bool queue_trunc = false;
3107        bool queue_invalidate = false;
3108        bool deleted_inode = false;
3109        bool fill_inline = false;
3110
3111        dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
3112             inode, cap, session->s_mds, seq, ceph_cap_string(newcaps));
3113        dout(" size %llu max_size %llu, i_size %llu\n", size, max_size,
3114                inode->i_size);
3115
3116
3117        /*
3118         * If CACHE is being revoked, and we have no dirty buffers,
3119         * try to invalidate (once).  (If there are dirty buffers, we
3120         * will invalidate _after_ writeback.)
3121         */
3122        if (!S_ISDIR(inode->i_mode) && /* don't invalidate readdir cache */
3123            ((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) &&
3124            (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
3125            !(ci->i_wrbuffer_ref || ci->i_wb_ref)) {
3126                if (try_nonblocking_invalidate(inode)) {
3127                        /* there were locked pages.. invalidate later
3128                           in a separate thread. */
3129                        if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
3130                                queue_invalidate = true;
3131                                ci->i_rdcache_revoking = ci->i_rdcache_gen;
3132                        }
3133                }
3134        }
3135
3136        if (was_stale)
3137                cap->issued = cap->implemented = CEPH_CAP_PIN;
3138
3139        /*
3140         * auth mds of the inode changed. we received the cap export message,
3141         * but still haven't received the cap import message. handle_cap_export
3142         * updated the new auth MDS' cap.
3143         *
3144         * "ceph_seq_cmp(seq, cap->seq) <= 0" means we are processing a message
3145         * that was sent before the cap import message. So don't remove caps.
3146         */
3147        if (ceph_seq_cmp(seq, cap->seq) <= 0) {
3148                WARN_ON(cap != ci->i_auth_cap);
3149                WARN_ON(cap->cap_id != le64_to_cpu(grant->cap_id));
3150                seq = cap->seq;
3151                newcaps |= cap->issued;
3152        }
3153
3154        /* side effects now are allowed */
3155        cap->cap_gen = session->s_cap_gen;
3156        cap->seq = seq;
3157
3158        __check_cap_issue(ci, cap, newcaps);
3159
3160        inode_set_max_iversion_raw(inode, extra_info->change_attr);
3161
3162        if ((newcaps & CEPH_CAP_AUTH_SHARED) &&
3163            (extra_info->issued & CEPH_CAP_AUTH_EXCL) == 0) {
3164                inode->i_mode = le32_to_cpu(grant->mode);
3165                inode->i_uid = make_kuid(&init_user_ns, le32_to_cpu(grant->uid));
3166                inode->i_gid = make_kgid(&init_user_ns, le32_to_cpu(grant->gid));
3167                ci->i_btime = extra_info->btime;
3168                dout("%p mode 0%o uid.gid %d.%d\n", inode, inode->i_mode,
3169                     from_kuid(&init_user_ns, inode->i_uid),
3170                     from_kgid(&init_user_ns, inode->i_gid));
3171        }
3172
3173        if ((newcaps & CEPH_CAP_LINK_SHARED) &&
3174            (extra_info->issued & CEPH_CAP_LINK_EXCL) == 0) {
3175                set_nlink(inode, le32_to_cpu(grant->nlink));
3176                if (inode->i_nlink == 0 &&
3177                    (newcaps & (CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL)))
3178                        deleted_inode = true;
3179        }
3180
3181        if ((extra_info->issued & CEPH_CAP_XATTR_EXCL) == 0 &&
3182            grant->xattr_len) {
3183                int len = le32_to_cpu(grant->xattr_len);
3184                u64 version = le64_to_cpu(grant->xattr_version);
3185
3186                if (version > ci->i_xattrs.version) {
3187                        dout(" got new xattrs v%llu on %p len %d\n",
3188                             version, inode, len);
3189                        if (ci->i_xattrs.blob)
3190                                ceph_buffer_put(ci->i_xattrs.blob);
3191                        ci->i_xattrs.blob = ceph_buffer_get(xattr_buf);
3192                        ci->i_xattrs.version = version;
3193                        ceph_forget_all_cached_acls(inode);
3194                        ceph_security_invalidate_secctx(inode);
3195                }
3196        }
3197
3198        if (newcaps & CEPH_CAP_ANY_RD) {
3199                struct timespec64 mtime, atime, ctime;
3200                /* ctime/mtime/atime? */
3201                ceph_decode_timespec64(&mtime, &grant->mtime);
3202                ceph_decode_timespec64(&atime, &grant->atime);
3203                ceph_decode_timespec64(&ctime, &grant->ctime);
3204                ceph_fill_file_time(inode, extra_info->issued,
3205                                    le32_to_cpu(grant->time_warp_seq),
3206                                    &ctime, &mtime, &atime);
3207        }
3208
3209        if ((newcaps & CEPH_CAP_FILE_SHARED) && extra_info->dirstat_valid) {
3210                ci->i_files = extra_info->nfiles;
3211                ci->i_subdirs = extra_info->nsubdirs;
3212        }
3213
3214        if (newcaps & (CEPH_CAP_ANY_FILE_RD | CEPH_CAP_ANY_FILE_WR)) {
3215                /* file layout may have changed */
3216                s64 old_pool = ci->i_layout.pool_id;
3217                struct ceph_string *old_ns;
3218
3219                ceph_file_layout_from_legacy(&ci->i_layout, &grant->layout);
3220                old_ns = rcu_dereference_protected(ci->i_layout.pool_ns,
3221                                        lockdep_is_held(&ci->i_ceph_lock));
3222                rcu_assign_pointer(ci->i_layout.pool_ns, extra_info->pool_ns);
3223
3224                if (ci->i_layout.pool_id != old_pool ||
3225                    extra_info->pool_ns != old_ns)
3226                        ci->i_ceph_flags &= ~CEPH_I_POOL_PERM;
3227
3228                extra_info->pool_ns = old_ns;
3229
3230                /* size/truncate_seq? */
3231                queue_trunc = ceph_fill_file_size(inode, extra_info->issued,
3232                                        le32_to_cpu(grant->truncate_seq),
3233                                        le64_to_cpu(grant->truncate_size),
3234                                        size);
3235        }
3236
3237        if (ci->i_auth_cap == cap && (newcaps & CEPH_CAP_ANY_FILE_WR)) {
3238                if (max_size != ci->i_max_size) {
3239                        dout("max_size %lld -> %llu\n",
3240                             ci->i_max_size, max_size);
3241                        ci->i_max_size = max_size;
3242                        if (max_size >= ci->i_wanted_max_size) {
3243                                ci->i_wanted_max_size = 0;  /* reset */
3244                                ci->i_requested_max_size = 0;
3245                        }
3246                        wake = true;
3247                } else if (ci->i_wanted_max_size > ci->i_max_size &&
3248                           ci->i_wanted_max_size > ci->i_requested_max_size) {
3249                        /* CEPH_CAP_OP_IMPORT */
3250                        wake = true;
3251                }
3252        }
3253
3254        /* check cap bits */
3255        wanted = __ceph_caps_wanted(ci);
3256        used = __ceph_caps_used(ci);
3257        dirty = __ceph_caps_dirty(ci);
3258        dout(" my wanted = %s, used = %s, dirty %s\n",
3259             ceph_cap_string(wanted),
3260             ceph_cap_string(used),
3261             ceph_cap_string(dirty));
3262
3263        if ((was_stale || le32_to_cpu(grant->op) == CEPH_CAP_OP_IMPORT) &&
3264            (wanted & ~(cap->mds_wanted | newcaps))) {
3265                /*
3266                 * If mds is importing cap, prior cap messages that update
3267                 * 'wanted' may get dropped by mds (migrate seq mismatch).
3268                 *
3269                 * We don't send cap message to update 'wanted' if what we
3270                 * want are already issued. If mds revokes caps, cap message
3271                 * that releases caps also tells mds what we want. But if
3272                 * caps got revoked by mds forcedly (session stale). We may
3273                 * haven't told mds what we want.
3274                 */
3275                check_caps = 1;
3276        }
3277
3278        /* revocation, grant, or no-op? */
3279        if (cap->issued & ~newcaps) {
3280                int revoking = cap->issued & ~newcaps;
3281
3282                dout("revocation: %s -> %s (revoking %s)\n",
3283                     ceph_cap_string(cap->issued),
3284                     ceph_cap_string(newcaps),
3285                     ceph_cap_string(revoking));
3286                if (revoking & used & CEPH_CAP_FILE_BUFFER)
3287                        writeback = true;  /* initiate writeback; will delay ack */
3288                else if (revoking == CEPH_CAP_FILE_CACHE &&
3289                         (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
3290                         queue_invalidate)
3291                        ; /* do nothing yet, invalidation will be queued */
3292                else if (cap == ci->i_auth_cap)
3293                        check_caps = 1; /* check auth cap only */
3294                else
3295                        check_caps = 2; /* check all caps */
3296                cap->issued = newcaps;
3297                cap->implemented |= newcaps;
3298        } else if (cap->issued == newcaps) {
3299                dout("caps unchanged: %s -> %s\n",
3300                     ceph_cap_string(cap->issued), ceph_cap_string(newcaps));
3301        } else {
3302                dout("grant: %s -> %s\n", ceph_cap_string(cap->issued),
3303                     ceph_cap_string(newcaps));
3304                /* non-auth MDS is revoking the newly grant caps ? */
3305                if (cap == ci->i_auth_cap &&
3306                    __ceph_caps_revoking_other(ci, cap, newcaps))
3307                    check_caps = 2;
3308
3309                cap->issued = newcaps;
3310                cap->implemented |= newcaps; /* add bits only, to
3311                                              * avoid stepping on a
3312                                              * pending revocation */
3313                wake = true;
3314        }
3315        BUG_ON(cap->issued & ~cap->implemented);
3316
3317        if (extra_info->inline_version > 0 &&
3318            extra_info->inline_version >= ci->i_inline_version) {
3319                ci->i_inline_version = extra_info->inline_version;
3320                if (ci->i_inline_version != CEPH_INLINE_NONE &&
3321                    (newcaps & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)))
3322                        fill_inline = true;
3323        }
3324
3325        if (le32_to_cpu(grant->op) == CEPH_CAP_OP_IMPORT) {
3326                if (newcaps & ~extra_info->issued)
3327                        wake = true;
3328                kick_flushing_inode_caps(session->s_mdsc, session, inode);
3329                up_read(&session->s_mdsc->snap_rwsem);
3330        } else {
3331                spin_unlock(&ci->i_ceph_lock);
3332        }
3333
3334        if (fill_inline)
3335                ceph_fill_inline_data(inode, NULL, extra_info->inline_data,
3336                                      extra_info->inline_len);
3337
3338        if (queue_trunc)
3339                ceph_queue_vmtruncate(inode);
3340
3341        if (writeback)
3342                /*
3343                 * queue inode for writeback: we can't actually call
3344                 * filemap_write_and_wait, etc. from message handler
3345                 * context.
3346                 */
3347                ceph_queue_writeback(inode);
3348        if (queue_invalidate)
3349                ceph_queue_invalidate(inode);
3350        if (deleted_inode)
3351                invalidate_aliases(inode);
3352        if (wake)
3353                wake_up_all(&ci->i_cap_wq);
3354
3355        if (check_caps == 1)
3356                ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
3357                                session);
3358        else if (check_caps == 2)
3359                ceph_check_caps(ci, CHECK_CAPS_NODELAY, session);
3360        else
3361                mutex_unlock(&session->s_mutex);
3362}
3363
3364/*
3365 * Handle FLUSH_ACK from MDS, indicating that metadata we sent to the
3366 * MDS has been safely committed.
3367 */
3368static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
3369                                 struct ceph_mds_caps *m,
3370                                 struct ceph_mds_session *session,
3371                                 struct ceph_cap *cap)
3372        __releases(ci->i_ceph_lock)
3373{
3374        struct ceph_inode_info *ci = ceph_inode(inode);
3375        struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
3376        struct ceph_cap_flush *cf, *tmp_cf;
3377        LIST_HEAD(to_remove);
3378        unsigned seq = le32_to_cpu(m->seq);
3379        int dirty = le32_to_cpu(m->dirty);
3380        int cleaned = 0;
3381        bool drop = false;
3382        bool wake_ci = false;
3383        bool wake_mdsc = false;
3384
3385        list_for_each_entry_safe(cf, tmp_cf, &ci->i_cap_flush_list, i_list) {
3386                if (cf->tid == flush_tid)
3387                        cleaned = cf->caps;
3388                if (cf->caps == 0) /* capsnap */
3389                        continue;
3390                if (cf->tid <= flush_tid) {
3391                        if (__finish_cap_flush(NULL, ci, cf))
3392                                wake_ci = true;
3393                        list_add_tail(&cf->i_list, &to_remove);
3394                } else {
3395                        cleaned &= ~cf->caps;
3396                        if (!cleaned)
3397                                break;
3398                }
3399        }
3400
3401        dout("handle_cap_flush_ack inode %p mds%d seq %d on %s cleaned %s,"
3402             " flushing %s -> %s\n",
3403             inode, session->s_mds, seq, ceph_cap_string(dirty),
3404             ceph_cap_string(cleaned), ceph_cap_string(ci->i_flushing_caps),
3405             ceph_cap_string(ci->i_flushing_caps & ~cleaned));
3406
3407        if (list_empty(&to_remove) && !cleaned)
3408                goto out;
3409
3410        ci->i_flushing_caps &= ~cleaned;
3411
3412        spin_lock(&mdsc->cap_dirty_lock);
3413
3414        list_for_each_entry(cf, &to_remove, i_list) {
3415                if (__finish_cap_flush(mdsc, NULL, cf))
3416                        wake_mdsc = true;
3417        }
3418
3419        if (ci->i_flushing_caps == 0) {
3420                if (list_empty(&ci->i_cap_flush_list)) {
3421                        list_del_init(&ci->i_flushing_item);
3422                        if (!list_empty(&session->s_cap_flushing)) {
3423                                dout(" mds%d still flushing cap on %p\n",
3424                                     session->s_mds,
3425                                     &list_first_entry(&session->s_cap_flushing,
3426                                                struct ceph_inode_info,
3427                                                i_flushing_item)->vfs_inode);
3428                        }
3429                }
3430                mdsc->num_cap_flushing--;
3431                dout(" inode %p now !flushing\n", inode);
3432
3433                if (ci->i_dirty_caps == 0) {
3434                        dout(" inode %p now clean\n", inode);
3435                        BUG_ON(!list_empty(&ci->i_dirty_item));
3436                        drop = true;
3437                        if (ci->i_wr_ref == 0 &&
3438                            ci->i_wrbuffer_ref_head == 0) {
3439                                BUG_ON(!ci->i_head_snapc);
3440                                ceph_put_snap_context(ci->i_head_snapc);
3441                                ci->i_head_snapc = NULL;
3442                        }
3443                } else {
3444                        BUG_ON(list_empty(&ci->i_dirty_item));
3445                }
3446        }
3447        spin_unlock(&mdsc->cap_dirty_lock);
3448
3449out:
3450        spin_unlock(&ci->i_ceph_lock);
3451
3452        while (!list_empty(&to_remove)) {
3453                cf = list_first_entry(&to_remove,
3454                                      struct ceph_cap_flush, i_list);
3455                list_del(&cf->i_list);
3456                ceph_free_cap_flush(cf);
3457        }
3458
3459        if (wake_ci)
3460                wake_up_all(&ci->i_cap_wq);
3461        if (wake_mdsc)
3462                wake_up_all(&mdsc->cap_flushing_wq);
3463        if (drop)
3464                iput(inode);
3465}
3466
3467/*
3468 * Handle FLUSHSNAP_ACK.  MDS has flushed snap data to disk and we can
3469 * throw away our cap_snap.
3470 *
3471 * Caller hold s_mutex.
3472 */
3473static void handle_cap_flushsnap_ack(struct inode *inode, u64 flush_tid,
3474                                     struct ceph_mds_caps *m,
3475                                     struct ceph_mds_session *session)
3476{
3477        struct ceph_inode_info *ci = ceph_inode(inode);
3478        struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
3479        u64 follows = le64_to_cpu(m->snap_follows);
3480        struct ceph_cap_snap *capsnap;
3481        bool flushed = false;
3482        bool wake_ci = false;
3483        bool wake_mdsc = false;
3484
3485        dout("handle_cap_flushsnap_ack inode %p ci %p mds%d follows %lld\n",
3486             inode, ci, session->s_mds, follows);
3487
3488        spin_lock(&ci->i_ceph_lock);
3489        list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
3490                if (capsnap->follows == follows) {
3491                        if (capsnap->cap_flush.tid != flush_tid) {
3492                                dout(" cap_snap %p follows %lld tid %lld !="
3493                                     " %lld\n", capsnap, follows,
3494                                     flush_tid, capsnap->cap_flush.tid);
3495                                break;
3496                        }
3497                        flushed = true;
3498                        break;
3499                } else {
3500                        dout(" skipping cap_snap %p follows %lld\n",
3501                             capsnap, capsnap->follows);
3502                }
3503        }
3504        if (flushed) {
3505                WARN_ON(capsnap->dirty_pages || capsnap->writing);
3506                dout(" removing %p cap_snap %p follows %lld\n",
3507                     inode, capsnap, follows);
3508                list_del(&capsnap->ci_item);
3509                if (__finish_cap_flush(NULL, ci, &capsnap->cap_flush))
3510                        wake_ci = true;
3511
3512                spin_lock(&mdsc->cap_dirty_lock);
3513
3514                if (list_empty(&ci->i_cap_flush_list))
3515                        list_del_init(&ci->i_flushing_item);
3516
3517                if (__finish_cap_flush(mdsc, NULL, &capsnap->cap_flush))
3518                        wake_mdsc = true;
3519
3520                spin_unlock(&mdsc->cap_dirty_lock);
3521        }
3522        spin_unlock(&ci->i_ceph_lock);
3523        if (flushed) {
3524                ceph_put_snap_context(capsnap->context);
3525                ceph_put_cap_snap(capsnap);
3526                if (wake_ci)
3527                        wake_up_all(&ci->i_cap_wq);
3528                if (wake_mdsc)
3529                        wake_up_all(&mdsc->cap_flushing_wq);
3530                iput(inode);
3531        }
3532}
3533
3534/*
3535 * Handle TRUNC from MDS, indicating file truncation.
3536 *
3537 * caller hold s_mutex.
3538 */
3539static void handle_cap_trunc(struct inode *inode,
3540                             struct ceph_mds_caps *trunc,
3541                             struct ceph_mds_session *session)
3542        __releases(ci->i_ceph_lock)
3543{
3544        struct ceph_inode_info *ci = ceph_inode(inode);
3545        int mds = session->s_mds;
3546        int seq = le32_to_cpu(trunc->seq);
3547        u32 truncate_seq = le32_to_cpu(trunc->truncate_seq);
3548        u64 truncate_size = le64_to_cpu(trunc->truncate_size);
3549        u64 size = le64_to_cpu(trunc->size);
3550        int implemented = 0;
3551        int dirty = __ceph_caps_dirty(ci);
3552        int issued = __ceph_caps_issued(ceph_inode(inode), &implemented);
3553        int queue_trunc = 0;
3554
3555        issued |= implemented | dirty;
3556
3557        dout("handle_cap_trunc inode %p mds%d seq %d to %lld seq %d\n",
3558             inode, mds, seq, truncate_size, truncate_seq);
3559        queue_trunc = ceph_fill_file_size(inode, issued,
3560                                          truncate_seq, truncate_size, size);
3561        spin_unlock(&ci->i_ceph_lock);
3562
3563        if (queue_trunc)
3564                ceph_queue_vmtruncate(inode);
3565}
3566
3567/*
3568 * Handle EXPORT from MDS.  Cap is being migrated _from_ this mds to a
3569 * different one.  If we are the most recent migration we've seen (as
3570 * indicated by mseq), make note of the migrating cap bits for the
3571 * duration (until we see the corresponding IMPORT).
3572 *
3573 * caller holds s_mutex
3574 */
3575static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
3576                              struct ceph_mds_cap_peer *ph,
3577                              struct ceph_mds_session *session)
3578{
3579        struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
3580        struct ceph_mds_session *tsession = NULL;
3581        struct ceph_cap *cap, *tcap, *new_cap = NULL;
3582        struct ceph_inode_info *ci = ceph_inode(inode);
3583        u64 t_cap_id;
3584        unsigned mseq = le32_to_cpu(ex->migrate_seq);
3585        unsigned t_seq, t_mseq;
3586        int target, issued;
3587        int mds = session->s_mds;
3588
3589        if (ph) {
3590                t_cap_id = le64_to_cpu(ph->cap_id);
3591                t_seq = le32_to_cpu(ph->seq);
3592                t_mseq = le32_to_cpu(ph->mseq);
3593                target = le32_to_cpu(ph->mds);
3594        } else {
3595                t_cap_id = t_seq = t_mseq = 0;
3596                target = -1;
3597        }
3598
3599        dout("handle_cap_export inode %p ci %p mds%d mseq %d target %d\n",
3600             inode, ci, mds, mseq, target);
3601retry:
3602        spin_lock(&ci->i_ceph_lock);
3603        cap = __get_cap_for_mds(ci, mds);
3604        if (!cap || cap->cap_id != le64_to_cpu(ex->cap_id))
3605                goto out_unlock;
3606
3607        if (target < 0) {
3608                if (cap->mds_wanted | cap->issued)
3609                        ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
3610                __ceph_remove_cap(cap, false);
3611                goto out_unlock;
3612        }
3613
3614        /*
3615         * now we know we haven't received the cap import message yet
3616         * because the exported cap still exist.
3617         */
3618
3619        issued = cap->issued;
3620        if (issued != cap->implemented)
3621                pr_err_ratelimited("handle_cap_export: issued != implemented: "
3622                                "ino (%llx.%llx) mds%d seq %d mseq %d "
3623                                "issued %s implemented %s\n",
3624                                ceph_vinop(inode), mds, cap->seq, cap->mseq,
3625                                ceph_cap_string(issued),
3626                                ceph_cap_string(cap->implemented));
3627
3628
3629        tcap = __get_cap_for_mds(ci, target);
3630        if (tcap) {
3631                /* already have caps from the target */
3632                if (tcap->cap_id == t_cap_id &&
3633                    ceph_seq_cmp(tcap->seq, t_seq) < 0) {
3634                        dout(" updating import cap %p mds%d\n", tcap, target);
3635                        tcap->cap_id = t_cap_id;
3636                        tcap->seq = t_seq - 1;
3637                        tcap->issue_seq = t_seq - 1;
3638                        tcap->issued |= issued;
3639                        tcap->implemented |= issued;
3640                        if (cap == ci->i_auth_cap)
3641                                ci->i_auth_cap = tcap;
3642
3643                        if (!list_empty(&ci->i_cap_flush_list) &&
3644                            ci->i_auth_cap == tcap) {
3645                                spin_lock(&mdsc->cap_dirty_lock);
3646                                list_move_tail(&ci->i_flushing_item,
3647                                               &tcap->session->s_cap_flushing);
3648                                spin_unlock(&mdsc->cap_dirty_lock);
3649                        }
3650                }
3651                __ceph_remove_cap(cap, false);
3652                goto out_unlock;
3653        } else if (tsession) {
3654                /* add placeholder for the export tagert */
3655                int flag = (cap == ci->i_auth_cap) ? CEPH_CAP_FLAG_AUTH : 0;
3656                tcap = new_cap;
3657                ceph_add_cap(inode, tsession, t_cap_id, -1, issued, 0,
3658                             t_seq - 1, t_mseq, (u64)-1, flag, &new_cap);
3659
3660                if (!list_empty(&ci->i_cap_flush_list) &&
3661                    ci->i_auth_cap == tcap) {
3662                        spin_lock(&mdsc->cap_dirty_lock);
3663                        list_move_tail(&ci->i_flushing_item,
3664                                       &tcap->session->s_cap_flushing);
3665                        spin_unlock(&mdsc->cap_dirty_lock);
3666                }
3667
3668                __ceph_remove_cap(cap, false);
3669                goto out_unlock;
3670        }
3671
3672        spin_unlock(&ci->i_ceph_lock);
3673        mutex_unlock(&session->s_mutex);
3674
3675        /* open target session */
3676        tsession = ceph_mdsc_open_export_target_session(mdsc, target);
3677        if (!IS_ERR(tsession)) {
3678                if (mds > target) {
3679                        mutex_lock(&session->s_mutex);
3680                        mutex_lock_nested(&tsession->s_mutex,
3681                                          SINGLE_DEPTH_NESTING);
3682                } else {
3683                        mutex_lock(&tsession->s_mutex);
3684                        mutex_lock_nested(&session->s_mutex,
3685                                          SINGLE_DEPTH_NESTING);
3686                }
3687                new_cap = ceph_get_cap(mdsc, NULL);
3688        } else {
3689                WARN_ON(1);
3690                tsession = NULL;
3691                target = -1;
3692        }
3693        goto retry;
3694
3695out_unlock:
3696        spin_unlock(&ci->i_ceph_lock);
3697        mutex_unlock(&session->s_mutex);
3698        if (tsession) {
3699                mutex_unlock(&tsession->s_mutex);
3700                ceph_put_mds_session(tsession);
3701        }
3702        if (new_cap)
3703                ceph_put_cap(mdsc, new_cap);
3704}
3705
3706/*
3707 * Handle cap IMPORT.
3708 *
3709 * caller holds s_mutex. acquires i_ceph_lock
3710 */
3711static void handle_cap_import(struct ceph_mds_client *mdsc,
3712                              struct inode *inode, struct ceph_mds_caps *im,
3713                              struct ceph_mds_cap_peer *ph,
3714                              struct ceph_mds_session *session,
3715                              struct ceph_cap **target_cap, int *old_issued)
3716        __acquires(ci->i_ceph_lock)
3717{
3718        struct ceph_inode_info *ci = ceph_inode(inode);
3719        struct ceph_cap *cap, *ocap, *new_cap = NULL;
3720        int mds = session->s_mds;
3721        int issued;
3722        unsigned caps = le32_to_cpu(im->caps);
3723        unsigned wanted = le32_to_cpu(im->wanted);
3724        unsigned seq = le32_to_cpu(im->seq);
3725        unsigned mseq = le32_to_cpu(im->migrate_seq);
3726        u64 realmino = le64_to_cpu(im->realm);
3727        u64 cap_id = le64_to_cpu(im->cap_id);
3728        u64 p_cap_id;
3729        int peer;
3730
3731        if (ph) {
3732                p_cap_id = le64_to_cpu(ph->cap_id);
3733                peer = le32_to_cpu(ph->mds);
3734        } else {
3735                p_cap_id = 0;
3736                peer = -1;
3737        }
3738
3739        dout("handle_cap_import inode %p ci %p mds%d mseq %d peer %d\n",
3740             inode, ci, mds, mseq, peer);
3741
3742retry:
3743        spin_lock(&ci->i_ceph_lock);
3744        cap = __get_cap_for_mds(ci, mds);
3745        if (!cap) {
3746                if (!new_cap) {
3747                        spin_unlock(&ci->i_ceph_lock);
3748                        new_cap = ceph_get_cap(mdsc, NULL);
3749                        goto retry;
3750                }
3751                cap = new_cap;
3752        } else {
3753                if (new_cap) {
3754                        ceph_put_cap(mdsc, new_cap);
3755                        new_cap = NULL;
3756                }
3757        }
3758
3759        __ceph_caps_issued(ci, &issued);
3760        issued |= __ceph_caps_dirty(ci);
3761
3762        ceph_add_cap(inode, session, cap_id, -1, caps, wanted, seq, mseq,
3763                     realmino, CEPH_CAP_FLAG_AUTH, &new_cap);
3764
3765        ocap = peer >= 0 ? __get_cap_for_mds(ci, peer) : NULL;
3766        if (ocap && ocap->cap_id == p_cap_id) {
3767                dout(" remove export cap %p mds%d flags %d\n",
3768                     ocap, peer, ph->flags);
3769                if ((ph->flags & CEPH_CAP_FLAG_AUTH) &&
3770                    (ocap->seq != le32_to_cpu(ph->seq) ||
3771                     ocap->mseq != le32_to_cpu(ph->mseq))) {
3772                        pr_err_ratelimited("handle_cap_import: "
3773                                        "mismatched seq/mseq: ino (%llx.%llx) "
3774                                        "mds%d seq %d mseq %d importer mds%d "
3775                                        "has peer seq %d mseq %d\n",
3776                                        ceph_vinop(inode), peer, ocap->seq,
3777                                        ocap->mseq, mds, le32_to_cpu(ph->seq),
3778                                        le32_to_cpu(ph->mseq));
3779                }
3780                __ceph_remove_cap(ocap, (ph->flags & CEPH_CAP_FLAG_RELEASE));
3781        }
3782
3783        /* make sure we re-request max_size, if necessary */
3784        ci->i_requested_max_size = 0;
3785
3786        *old_issued = issued;
3787        *target_cap = cap;
3788}
3789
3790/*
3791 * Handle a caps message from the MDS.
3792 *
3793 * Identify the appropriate session, inode, and call the right handler
3794 * based on the cap op.
3795 */
3796void ceph_handle_caps(struct ceph_mds_session *session,
3797                      struct ceph_msg *msg)
3798{
3799        struct ceph_mds_client *mdsc = session->s_mdsc;
3800        struct inode *inode;
3801        struct ceph_inode_info *ci;
3802        struct ceph_cap *cap;
3803        struct ceph_mds_caps *h;
3804        struct ceph_mds_cap_peer *peer = NULL;
3805        struct ceph_snap_realm *realm = NULL;
3806        int op;
3807        int msg_version = le16_to_cpu(msg->hdr.version);
3808        u32 seq, mseq;
3809        struct ceph_vino vino;
3810        void *snaptrace;
3811        size_t snaptrace_len;
3812        void *p, *end;
3813        struct cap_extra_info extra_info = {};
3814
3815        dout("handle_caps from mds%d\n", session->s_mds);
3816
3817        /* decode */
3818        end = msg->front.iov_base + msg->front.iov_len;
3819        if (msg->front.iov_len < sizeof(*h))
3820                goto bad;
3821        h = msg->front.iov_base;
3822        op = le32_to_cpu(h->op);
3823        vino.ino = le64_to_cpu(h->ino);
3824        vino.snap = CEPH_NOSNAP;
3825        seq = le32_to_cpu(h->seq);
3826        mseq = le32_to_cpu(h->migrate_seq);
3827
3828        snaptrace = h + 1;
3829        snaptrace_len = le32_to_cpu(h->snap_trace_len);
3830        p = snaptrace + snaptrace_len;
3831
3832        if (msg_version >= 2) {
3833                u32 flock_len;
3834                ceph_decode_32_safe(&p, end, flock_len, bad);
3835                if (p + flock_len > end)
3836                        goto bad;
3837                p += flock_len;
3838        }
3839
3840        if (msg_version >= 3) {
3841                if (op == CEPH_CAP_OP_IMPORT) {
3842                        if (p + sizeof(*peer) > end)
3843                                goto bad;
3844                        peer = p;
3845                        p += sizeof(*peer);
3846                } else if (op == CEPH_CAP_OP_EXPORT) {
3847                        /* recorded in unused fields */
3848                        peer = (void *)&h->size;
3849                }
3850        }
3851
3852        if (msg_version >= 4) {
3853                ceph_decode_64_safe(&p, end, extra_info.inline_version, bad);
3854                ceph_decode_32_safe(&p, end, extra_info.inline_len, bad);
3855                if (p + extra_info.inline_len > end)
3856                        goto bad;
3857                extra_info.inline_data = p;
3858                p += extra_info.inline_len;
3859        }
3860
3861        if (msg_version >= 5) {
3862                struct ceph_osd_client  *osdc = &mdsc->fsc->client->osdc;
3863                u32                     epoch_barrier;
3864
3865                ceph_decode_32_safe(&p, end, epoch_barrier, bad);
3866                ceph_osdc_update_epoch_barrier(osdc, epoch_barrier);
3867        }
3868
3869        if (msg_version >= 8) {
3870                u64 flush_tid;
3871                u32 caller_uid, caller_gid;
3872                u32 pool_ns_len;
3873
3874                /* version >= 6 */
3875                ceph_decode_64_safe(&p, end, flush_tid, bad);
3876                /* version >= 7 */
3877                ceph_decode_32_safe(&p, end, caller_uid, bad);
3878                ceph_decode_32_safe(&p, end, caller_gid, bad);
3879                /* version >= 8 */
3880                ceph_decode_32_safe(&p, end, pool_ns_len, bad);
3881                if (pool_ns_len > 0) {
3882                        ceph_decode_need(&p, end, pool_ns_len, bad);
3883                        extra_info.pool_ns =
3884                                ceph_find_or_create_string(p, pool_ns_len);
3885                        p += pool_ns_len;
3886                }
3887        }
3888
3889        if (msg_version >= 9) {
3890                struct ceph_timespec *btime;
3891
3892                if (p + sizeof(*btime) > end)
3893                        goto bad;
3894                btime = p;
3895                ceph_decode_timespec64(&extra_info.btime, btime);
3896                p += sizeof(*btime);
3897                ceph_decode_64_safe(&p, end, extra_info.change_attr, bad);
3898        }
3899
3900        if (msg_version >= 11) {
3901                u32 flags;
3902                /* version >= 10 */
3903                ceph_decode_32_safe(&p, end, flags, bad);
3904                /* version >= 11 */
3905                extra_info.dirstat_valid = true;
3906                ceph_decode_64_safe(&p, end, extra_info.nfiles, bad);
3907                ceph_decode_64_safe(&p, end, extra_info.nsubdirs, bad);
3908        }
3909
3910        /* lookup ino */
3911        inode = ceph_find_inode(mdsc->fsc->sb, vino);
3912        ci = ceph_inode(inode);
3913        dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino,
3914             vino.snap, inode);
3915
3916        mutex_lock(&session->s_mutex);
3917        session->s_seq++;
3918        dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
3919             (unsigned)seq);
3920
3921        if (!inode) {
3922                dout(" i don't have ino %llx\n", vino.ino);
3923
3924                if (op == CEPH_CAP_OP_IMPORT) {
3925                        cap = ceph_get_cap(mdsc, NULL);
3926                        cap->cap_ino = vino.ino;
3927                        cap->queue_release = 1;
3928                        cap->cap_id = le64_to_cpu(h->cap_id);
3929                        cap->mseq = mseq;
3930                        cap->seq = seq;
3931                        cap->issue_seq = seq;
3932                        spin_lock(&session->s_cap_lock);
3933                        __ceph_queue_cap_release(session, cap);
3934                        spin_unlock(&session->s_cap_lock);
3935                }
3936                goto done;
3937        }
3938
3939        /* these will work even if we don't have a cap yet */
3940        switch (op) {
3941        case CEPH_CAP_OP_FLUSHSNAP_ACK:
3942                handle_cap_flushsnap_ack(inode, le64_to_cpu(msg->hdr.tid),
3943                                         h, session);
3944                goto done;
3945
3946        case CEPH_CAP_OP_EXPORT:
3947                handle_cap_export(inode, h, peer, session);
3948                goto done_unlocked;
3949
3950        case CEPH_CAP_OP_IMPORT:
3951                realm = NULL;
3952                if (snaptrace_len) {
3953                        down_write(&mdsc->snap_rwsem);
3954                        ceph_update_snap_trace(mdsc, snaptrace,
3955                                               snaptrace + snaptrace_len,
3956                                               false, &realm);
3957                        downgrade_write(&mdsc->snap_rwsem);
3958                } else {
3959                        down_read(&mdsc->snap_rwsem);
3960                }
3961                handle_cap_import(mdsc, inode, h, peer, session,
3962                                  &cap, &extra_info.issued);
3963                handle_cap_grant(inode, session, cap,
3964                                 h, msg->middle, &extra_info);
3965                if (realm)
3966                        ceph_put_snap_realm(mdsc, realm);
3967                goto done_unlocked;
3968        }
3969
3970        /* the rest require a cap */
3971        spin_lock(&ci->i_ceph_lock);
3972        cap = __get_cap_for_mds(ceph_inode(inode), session->s_mds);
3973        if (!cap) {
3974                dout(" no cap on %p ino %llx.%llx from mds%d\n",
3975                     inode, ceph_ino(inode), ceph_snap(inode),
3976                     session->s_mds);
3977                spin_unlock(&ci->i_ceph_lock);
3978                goto flush_cap_releases;
3979        }
3980
3981        /* note that each of these drops i_ceph_lock for us */
3982        switch (op) {
3983        case CEPH_CAP_OP_REVOKE:
3984        case CEPH_CAP_OP_GRANT:
3985                __ceph_caps_issued(ci, &extra_info.issued);
3986                extra_info.issued |= __ceph_caps_dirty(ci);
3987                handle_cap_grant(inode, session, cap,
3988                                 h, msg->middle, &extra_info);
3989                goto done_unlocked;
3990
3991        case CEPH_CAP_OP_FLUSH_ACK:
3992                handle_cap_flush_ack(inode, le64_to_cpu(msg->hdr.tid),
3993                                     h, session, cap);
3994                break;
3995
3996        case CEPH_CAP_OP_TRUNC:
3997                handle_cap_trunc(inode, h, session);
3998                break;
3999
4000        default:
4001                spin_unlock(&ci->i_ceph_lock);
4002                pr_err("ceph_handle_caps: unknown cap op %d %s\n", op,
4003                       ceph_cap_op_name(op));
4004        }
4005
4006done:
4007        mutex_unlock(&session->s_mutex);
4008done_unlocked:
4009        ceph_put_string(extra_info.pool_ns);
4010        /* avoid calling iput_final() in mds dispatch threads */
4011        ceph_async_iput(inode);
4012        return;
4013
4014flush_cap_releases:
4015        /*
4016         * send any cap release message to try to move things
4017         * along for the mds (who clearly thinks we still have this
4018         * cap).
4019         */
4020        ceph_flush_cap_releases(mdsc, session);
4021        goto done;
4022
4023bad:
4024        pr_err("ceph_handle_caps: corrupt message\n");
4025        ceph_msg_dump(msg);
4026        return;
4027}
4028
4029/*
4030 * Delayed work handler to process end of delayed cap release LRU list.
4031 */
4032void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
4033{
4034        struct inode *inode;
4035        struct ceph_inode_info *ci;
4036        int flags = CHECK_CAPS_NODELAY;
4037
4038        dout("check_delayed_caps\n");
4039        while (1) {
4040                spin_lock(&mdsc->cap_delay_lock);
4041                if (list_empty(&mdsc->cap_delay_list))
4042                        break;
4043                ci = list_first_entry(&mdsc->cap_delay_list,
4044                                      struct ceph_inode_info,
4045                                      i_cap_delay_list);
4046                if ((ci->i_ceph_flags & CEPH_I_FLUSH) == 0 &&
4047                    time_before(jiffies, ci->i_hold_caps_max))
4048                        break;
4049                list_del_init(&ci->i_cap_delay_list);
4050
4051                inode = igrab(&ci->vfs_inode);
4052                spin_unlock(&mdsc->cap_delay_lock);
4053
4054                if (inode) {
4055                        dout("check_delayed_caps on %p\n", inode);
4056                        ceph_check_caps(ci, flags, NULL);
4057                        /* avoid calling iput_final() in tick thread */
4058                        ceph_async_iput(inode);
4059                }
4060        }
4061        spin_unlock(&mdsc->cap_delay_lock);
4062}
4063
4064/*
4065 * Flush all dirty caps to the mds
4066 */
4067void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
4068{
4069        struct ceph_inode_info *ci;
4070        struct inode *inode;
4071
4072        dout("flush_dirty_caps\n");
4073        spin_lock(&mdsc->cap_dirty_lock);
4074        while (!list_empty(&mdsc->cap_dirty)) {
4075                ci = list_first_entry(&mdsc->cap_dirty, struct ceph_inode_info,
4076                                      i_dirty_item);
4077                inode = &ci->vfs_inode;
4078                ihold(inode);
4079                dout("flush_dirty_caps %p\n", inode);
4080                spin_unlock(&mdsc->cap_dirty_lock);
4081                ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH, NULL);
4082                iput(inode);
4083                spin_lock(&mdsc->cap_dirty_lock);
4084        }
4085        spin_unlock(&mdsc->cap_dirty_lock);
4086        dout("flush_dirty_caps done\n");
4087}
4088
4089void __ceph_get_fmode(struct ceph_inode_info *ci, int fmode)
4090{
4091        int i;
4092        int bits = (fmode << 1) | 1;
4093        for (i = 0; i < CEPH_FILE_MODE_BITS; i++) {
4094                if (bits & (1 << i))
4095                        ci->i_nr_by_mode[i]++;
4096        }
4097}
4098
4099/*
4100 * Drop open file reference.  If we were the last open file,
4101 * we may need to release capabilities to the MDS (or schedule
4102 * their delayed release).
4103 */
4104void ceph_put_fmode(struct ceph_inode_info *ci, int fmode)
4105{
4106        int i, last = 0;
4107        int bits = (fmode << 1) | 1;
4108        spin_lock(&ci->i_ceph_lock);
4109        for (i = 0; i < CEPH_FILE_MODE_BITS; i++) {
4110                if (bits & (1 << i)) {
4111                        BUG_ON(ci->i_nr_by_mode[i] == 0);
4112                        if (--ci->i_nr_by_mode[i] == 0)
4113                                last++;
4114                }
4115        }
4116        dout("put_fmode %p fmode %d {%d,%d,%d,%d}\n",
4117             &ci->vfs_inode, fmode,
4118             ci->i_nr_by_mode[0], ci->i_nr_by_mode[1],
4119             ci->i_nr_by_mode[2], ci->i_nr_by_mode[3]);
4120        spin_unlock(&ci->i_ceph_lock);
4121
4122        if (last && ci->i_vino.snap == CEPH_NOSNAP)
4123                ceph_check_caps(ci, 0, NULL);
4124}
4125
4126/*
4127 * For a soon-to-be unlinked file, drop the LINK caps. If it
4128 * looks like the link count will hit 0, drop any other caps (other
4129 * than PIN) we don't specifically want (due to the file still being
4130 * open).
4131 */
4132int ceph_drop_caps_for_unlink(struct inode *inode)
4133{
4134        struct ceph_inode_info *ci = ceph_inode(inode);
4135        int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
4136
4137        spin_lock(&ci->i_ceph_lock);
4138        if (inode->i_nlink == 1) {
4139                drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
4140
4141                ci->i_ceph_flags |= CEPH_I_NODELAY;
4142                if (__ceph_caps_dirty(ci)) {
4143                        struct ceph_mds_client *mdsc =
4144                                ceph_inode_to_client(inode)->mdsc;
4145                        __cap_delay_requeue_front(mdsc, ci);
4146                }
4147        }
4148        spin_unlock(&ci->i_ceph_lock);
4149        return drop;
4150}
4151
4152/*
4153 * Helpers for embedding cap and dentry lease releases into mds
4154 * requests.
4155 *
4156 * @force is used by dentry_release (below) to force inclusion of a
4157 * record for the directory inode, even when there aren't any caps to
4158 * drop.
4159 */
4160int ceph_encode_inode_release(void **p, struct inode *inode,
4161                              int mds, int drop, int unless, int force)
4162{
4163        struct ceph_inode_info *ci = ceph_inode(inode);
4164        struct ceph_cap *cap;
4165        struct ceph_mds_request_release *rel = *p;
4166        int used, dirty;
4167        int ret = 0;
4168
4169        spin_lock(&ci->i_ceph_lock);
4170        used = __ceph_caps_used(ci);
4171        dirty = __ceph_caps_dirty(ci);
4172
4173        dout("encode_inode_release %p mds%d used|dirty %s drop %s unless %s\n",
4174             inode, mds, ceph_cap_string(used|dirty), ceph_cap_string(drop),
4175             ceph_cap_string(unless));
4176
4177        /* only drop unused, clean caps */
4178        drop &= ~(used | dirty);
4179
4180        cap = __get_cap_for_mds(ci, mds);
4181        if (cap && __cap_is_valid(cap)) {
4182                unless &= cap->issued;
4183                if (unless) {
4184                        if (unless & CEPH_CAP_AUTH_EXCL)
4185                                drop &= ~CEPH_CAP_AUTH_SHARED;
4186                        if (unless & CEPH_CAP_LINK_EXCL)
4187                                drop &= ~CEPH_CAP_LINK_SHARED;
4188                        if (unless & CEPH_CAP_XATTR_EXCL)
4189                                drop &= ~CEPH_CAP_XATTR_SHARED;
4190                        if (unless & CEPH_CAP_FILE_EXCL)
4191                                drop &= ~CEPH_CAP_FILE_SHARED;
4192                }
4193
4194                if (force || (cap->issued & drop)) {
4195                        if (cap->issued & drop) {
4196                                int wanted = __ceph_caps_wanted(ci);
4197                                if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0)
4198                                        wanted |= cap->mds_wanted;
4199                                dout("encode_inode_release %p cap %p "
4200                                     "%s -> %s, wanted %s -> %s\n", inode, cap,
4201                                     ceph_cap_string(cap->issued),
4202                                     ceph_cap_string(cap->issued & ~drop),
4203                                     ceph_cap_string(cap->mds_wanted),
4204                                     ceph_cap_string(wanted));
4205
4206                                cap->issued &= ~drop;
4207                                cap->implemented &= ~drop;
4208                                cap->mds_wanted = wanted;
4209                        } else {
4210                                dout("encode_inode_release %p cap %p %s"
4211                                     " (force)\n", inode, cap,
4212                                     ceph_cap_string(cap->issued));
4213                        }
4214
4215                        rel->ino = cpu_to_le64(ceph_ino(inode));
4216                        rel->cap_id = cpu_to_le64(cap->cap_id);
4217                        rel->seq = cpu_to_le32(cap->seq);
4218                        rel->issue_seq = cpu_to_le32(cap->issue_seq);
4219                        rel->mseq = cpu_to_le32(cap->mseq);
4220                        rel->caps = cpu_to_le32(cap->implemented);
4221                        rel->wanted = cpu_to_le32(cap->mds_wanted);
4222                        rel->dname_len = 0;
4223                        rel->dname_seq = 0;
4224                        *p += sizeof(*rel);
4225                        ret = 1;
4226                } else {
4227                        dout("encode_inode_release %p cap %p %s (noop)\n",
4228                             inode, cap, ceph_cap_string(cap->issued));
4229                }
4230        }
4231        spin_unlock(&ci->i_ceph_lock);
4232        return ret;
4233}
4234
4235int ceph_encode_dentry_release(void **p, struct dentry *dentry,
4236                               struct inode *dir,
4237                               int mds, int drop, int unless)
4238{
4239        struct dentry *parent = NULL;
4240        struct ceph_mds_request_release *rel = *p;
4241        struct ceph_dentry_info *di = ceph_dentry(dentry);
4242        int force = 0;
4243        int ret;
4244
4245        /*
4246         * force an record for the directory caps if we have a dentry lease.
4247         * this is racy (can't take i_ceph_lock and d_lock together), but it
4248         * doesn't have to be perfect; the mds will revoke anything we don't
4249         * release.
4250         */
4251        spin_lock(&dentry->d_lock);
4252        if (di->lease_session && di->lease_session->s_mds == mds)
4253                force = 1;
4254        if (!dir) {
4255                parent = dget(dentry->d_parent);
4256                dir = d_inode(parent);
4257        }
4258        spin_unlock(&dentry->d_lock);
4259
4260        ret = ceph_encode_inode_release(p, dir, mds, drop, unless, force);
4261        dput(parent);
4262
4263        spin_lock(&dentry->d_lock);
4264        if (ret && di->lease_session && di->lease_session->s_mds == mds) {
4265                dout("encode_dentry_release %p mds%d seq %d\n",
4266                     dentry, mds, (int)di->lease_seq);
4267                rel->dname_len = cpu_to_le32(dentry->d_name.len);
4268                memcpy(*p, dentry->d_name.name, dentry->d_name.len);
4269                *p += dentry->d_name.len;
4270                rel->dname_seq = cpu_to_le32(di->lease_seq);
4271                __ceph_mdsc_drop_dentry_lease(dentry);
4272        }
4273        spin_unlock(&dentry->d_lock);
4274        return ret;
4275}
4276