fs/cachefiles/io.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* kiocb-using read/write
   3  *
   4  * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #include <linux/mount.h>
   9 #include <linux/slab.h>
  10 #include <linux/file.h>
  11 #include <linux/uio.h>
  12 #include <linux/falloc.h>
  13 #include <linux/sched/mm.h>
  14 #include <trace/events/fscache.h>
  15 #include "internal.h"
  16
  17 struct cachefiles_kiocb {
  18         struct kiocb            iocb;
  19         refcount_t              ki_refcnt;
  20         loff_t                  start;
  21         union {
  22                 size_t          skipped;
  23                 size_t          len;
  24         };
  25         struct cachefiles_object *object;
  26         netfs_io_terminated_t   term_func;
  27         void                    *term_func_priv;
  28         bool                    was_async;
  29         unsigned int            inval_counter;  /* Copy of cookie->inval_counter */
  30         u64                     b_writing;
  31 };
  32
  33 static inline void cachefiles_put_kiocb(struct cachefiles_kiocb *ki)
  34 {
  35         if (refcount_dec_and_test(&ki->ki_refcnt)) {
  36                 cachefiles_put_object(ki->object, cachefiles_obj_put_ioreq);
  37                 fput(ki->iocb.ki_filp);
  38                 kfree(ki);
  39         }
  40 }
  41
  42 /*
  43  * Handle completion of a read from the cache.
  44  */
  45 static void cachefiles_read_complete(struct kiocb *iocb, long ret)
  46 {
  47         struct cachefiles_kiocb *ki = container_of(iocb, struct cachefiles_kiocb, iocb);
  48         struct inode *inode = file_inode(ki->iocb.ki_filp);
  49
  50         _enter("%ld", ret);
  51
  52         if (ret < 0)
  53                 trace_cachefiles_io_error(ki->object, inode, ret,
  54                                           cachefiles_trace_read_error);
  55
  56         if (ki->term_func) {
  57                 if (ret >= 0) {
  58                         if (ki->object->cookie->inval_counter == ki->inval_counter)
  59                                 ki->skipped += ret;
  60                         else
  61                                 ret = -ESTALE;
  62                 }
  63
  64                 ki->term_func(ki->term_func_priv, ret, ki->was_async);
  65         }
  66
  67         cachefiles_put_kiocb(ki);
  68 }
  69
  70 /*
  71  * Initiate a read from the cache.
  72  */
  73 static int cachefiles_read(struct netfs_cache_resources *cres,
  74                            loff_t start_pos,
  75                            struct iov_iter *iter,
  76                            enum netfs_read_from_hole read_hole,
  77                            netfs_io_terminated_t term_func,
  78                            void *term_func_priv)
  79 {
  80         struct cachefiles_object *object;
  81         struct cachefiles_kiocb *ki;
  82         struct file *file;
  83         unsigned int old_nofs;
  84         ssize_t ret = -ENOBUFS;
  85         size_t len = iov_iter_count(iter), skipped = 0;
  86
  87         if (!fscache_wait_for_operation(cres, FSCACHE_WANT_READ))
  88                 goto presubmission_error;
  89
  90         fscache_count_read();
  91         object = cachefiles_cres_object(cres);
  92         file = cachefiles_cres_file(cres);
  93
  94         _enter("%pD,%li,%llx,%zx/%llx",
  95                file, file_inode(file)->i_ino, start_pos, len,
  96                i_size_read(file_inode(file)));
  97
  98         /* If the caller asked us to seek for data before doing the read, then
  99          * we should do that now.  If we find a gap, we fill it with zeros.
 100          */
 101         if (read_hole != NETFS_READ_HOLE_IGNORE) {
 102                 loff_t off = start_pos, off2;
 103
 104                 off2 = cachefiles_inject_read_error();
 105                 if (off2 == 0)
 106                         off2 = vfs_llseek(file, off, SEEK_DATA);
 107                 if (off2 < 0 && off2 >= (loff_t)-MAX_ERRNO && off2 != -ENXIO) {
 108                         skipped = 0;
 109                         ret = off2;
 110                         goto presubmission_error;
 111                 }
 112
 113                 if (off2 == -ENXIO || off2 >= start_pos + len) {
 114                         /* The region is beyond the EOF or there's no more data
 115                          * in the region, so clear the rest of the buffer and
 116                          * return success.
 117                          */
 118                         ret = -ENODATA;
 119                         if (read_hole == NETFS_READ_HOLE_FAIL)
 120                                 goto presubmission_error;
 121
 122                         iov_iter_zero(len, iter);
 123                         skipped = len;
 124                         ret = 0;
 125                         goto presubmission_error;
 126                 }
 127
 128                 skipped = off2 - off;
 129                 iov_iter_zero(skipped, iter);
 130         }
 131
 132         ret = -ENOMEM;
 133         ki = kzalloc(sizeof(struct cachefiles_kiocb), GFP_KERNEL);
 134         if (!ki)
 135                 goto presubmission_error;
 136
 137         refcount_set(&ki->ki_refcnt, 2);
 138         ki->iocb.ki_filp        = file;
 139         ki->iocb.ki_pos         = start_pos + skipped;
 140         ki->iocb.ki_flags       = IOCB_DIRECT;
 141         ki->iocb.ki_ioprio      = get_current_ioprio();
 142         ki->skipped             = skipped;
 143         ki->object              = object;
 144         ki->inval_counter       = cres->inval_counter;
 145         ki->term_func           = term_func;
 146         ki->term_func_priv      = term_func_priv;
 147         ki->was_async           = true;
 148
 149         if (ki->term_func)
 150                 ki->iocb.ki_complete = cachefiles_read_complete;
 151
 152         get_file(ki->iocb.ki_filp);
 153         cachefiles_grab_object(object, cachefiles_obj_get_ioreq);
 154
 155         trace_cachefiles_read(object, file_inode(file), ki->iocb.ki_pos, len - skipped);
 156         old_nofs = memalloc_nofs_save();
 157         ret = cachefiles_inject_read_error();
 158         if (ret == 0)
 159                 ret = vfs_iocb_iter_read(file, &ki->iocb, iter);
 160         memalloc_nofs_restore(old_nofs);
 161         switch (ret) {
 162         case -EIOCBQUEUED:
 163                 goto in_progress;
 164
 165         case -ERESTARTSYS:
 166         case -ERESTARTNOINTR:
 167         case -ERESTARTNOHAND:
 168         case -ERESTART_RESTARTBLOCK:
 169                 /* There's no easy way to restart the syscall since other AIO's
 170                  * may be already running. Just fail this IO with EINTR.
 171                  */
 172                 ret = -EINTR;
 173                 fallthrough;
 174         default:
 175                 ki->was_async = false;
 176                 cachefiles_read_complete(&ki->iocb, ret);
 177                 if (ret > 0)
 178                         ret = 0;
 179                 break;
 180         }
 181
 182 in_progress:
 183         cachefiles_put_kiocb(ki);
 184         _leave(" = %zd", ret);
 185         return ret;
 186
 187 presubmission_error:
 188         if (term_func)
 189                 term_func(term_func_priv, ret < 0 ? ret : skipped, false);
 190         return ret;
 191 }
 192
 193 /*
 194  * Query the occupancy of the cache in a region, returning where the next chunk
 195  * of data starts and how long it is.
 196  */
 197 static int cachefiles_query_occupancy(struct netfs_cache_resources *cres,
 198                                       loff_t start, size_t len, size_t granularity,
 199                                       loff_t *_data_start, size_t *_data_len)
 200 {
 201         struct cachefiles_object *object;
 202         struct file *file;
 203         loff_t off, off2;
 204
 205         *_data_start = -1;
 206         *_data_len = 0;
 207
 208         if (!fscache_wait_for_operation(cres, FSCACHE_WANT_READ))
 209                 return -ENOBUFS;
 210
 211         object = cachefiles_cres_object(cres);
 212         file = cachefiles_cres_file(cres);
 213         granularity = max_t(size_t, object->volume->cache->bsize, granularity);
 214
 215         _enter("%pD,%li,%llx,%zx/%llx",
 216                file, file_inode(file)->i_ino, start, len,
 217                i_size_read(file_inode(file)));
 218
 219         off = cachefiles_inject_read_error();
 220         if (off == 0)
 221                 off = vfs_llseek(file, start, SEEK_DATA);
 222         if (off == -ENXIO)
 223                 return -ENODATA; /* Beyond EOF */
 224         if (off < 0 && off >= (loff_t)-MAX_ERRNO)
 225                 return -ENOBUFS; /* Error. */
 226         if (round_up(off, granularity) >= start + len)
 227                 return -ENODATA; /* No data in range */
 228
 229         off2 = cachefiles_inject_read_error();
 230         if (off2 == 0)
 231                 off2 = vfs_llseek(file, off, SEEK_HOLE);
 232         if (off2 == -ENXIO)
 233                 return -ENODATA; /* Beyond EOF */
 234         if (off2 < 0 && off2 >= (loff_t)-MAX_ERRNO)
 235                 return -ENOBUFS; /* Error. */
 236
 237         /* Round away partial blocks */
 238         off = round_up(off, granularity);
 239         off2 = round_down(off2, granularity);
 240         if (off2 <= off)
 241                 return -ENODATA;
 242
 243         *_data_start = off;
 244         if (off2 > start + len)
 245                 *_data_len = len;
 246         else
 247                 *_data_len = off2 - off;
 248         return 0;
 249 }
 250
 251 /*
 252  * Handle completion of a write to the cache.
 253  */
 254 static void cachefiles_write_complete(struct kiocb *iocb, long ret)
 255 {
 256         struct cachefiles_kiocb *ki = container_of(iocb, struct cachefiles_kiocb, iocb);
 257         struct cachefiles_object *object = ki->object;
 258         struct inode *inode = file_inode(ki->iocb.ki_filp);
 259
 260         _enter("%ld", ret);
 261
 262         /* Tell lockdep we inherited freeze protection from submission thread */
 263         __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
 264         __sb_end_write(inode->i_sb, SB_FREEZE_WRITE);
 265
 266         if (ret < 0)
 267                 trace_cachefiles_io_error(object, inode, ret,
 268                                           cachefiles_trace_write_error);
 269
 270         atomic_long_sub(ki->b_writing, &object->volume->cache->b_writing);
 271         set_bit(FSCACHE_COOKIE_HAVE_DATA, &object->cookie->flags);
 272         if (ki->term_func)
 273                 ki->term_func(ki->term_func_priv, ret, ki->was_async);
 274         cachefiles_put_kiocb(ki);
 275 }
 276
 277 /*
 278  * Initiate a write to the cache.
 279  */
 280 static int cachefiles_write(struct netfs_cache_resources *cres,
 281                             loff_t start_pos,
 282                             struct iov_iter *iter,
 283                             netfs_io_terminated_t term_func,
 284                             void *term_func_priv)
 285 {
 286         struct cachefiles_object *object;
 287         struct cachefiles_cache *cache;
 288         struct cachefiles_kiocb *ki;
 289         struct inode *inode;
 290         struct file *file;
 291         unsigned int old_nofs;
 292         ssize_t ret = -ENOBUFS;
 293         size_t len = iov_iter_count(iter);
 294
 295         if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE))
 296                 goto presubmission_error;
 297         fscache_count_write();
 298         object = cachefiles_cres_object(cres);
 299         cache = object->volume->cache;
 300         file = cachefiles_cres_file(cres);
 301
 302         _enter("%pD,%li,%llx,%zx/%llx",
 303                file, file_inode(file)->i_ino, start_pos, len,
 304                i_size_read(file_inode(file)));
 305
 306         ret = -ENOMEM;
 307         ki = kzalloc(sizeof(struct cachefiles_kiocb), GFP_KERNEL);
 308         if (!ki)
 309                 goto presubmission_error;
 310
 311         refcount_set(&ki->ki_refcnt, 2);
 312         ki->iocb.ki_filp        = file;
 313         ki->iocb.ki_pos         = start_pos;
 314         ki->iocb.ki_flags       = IOCB_DIRECT | IOCB_WRITE;
 315         ki->iocb.ki_ioprio      = get_current_ioprio();
 316         ki->object              = object;
 317         ki->inval_counter       = cres->inval_counter;
 318         ki->start               = start_pos;
 319         ki->len                 = len;
 320         ki->term_func           = term_func;
 321         ki->term_func_priv      = term_func_priv;
 322         ki->was_async           = true;
 323         ki->b_writing           = (len + (1 << cache->bshift) - 1) >> cache->bshift;
 324
 325         if (ki->term_func)
 326                 ki->iocb.ki_complete = cachefiles_write_complete;
 327         atomic_long_add(ki->b_writing, &cache->b_writing);
 328
 329         /* Open-code file_start_write here to grab freeze protection, which
 330          * will be released by another thread in aio_complete_rw().  Fool
 331          * lockdep by telling it the lock got released so that it doesn't
 332          * complain about the held lock when we return to userspace.
 333          */
 334         inode = file_inode(file);
 335         __sb_start_write(inode->i_sb, SB_FREEZE_WRITE);
 336         __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE);
 337
 338         get_file(ki->iocb.ki_filp);
 339         cachefiles_grab_object(object, cachefiles_obj_get_ioreq);
 340
 341         trace_cachefiles_write(object, inode, ki->iocb.ki_pos, len);
 342         old_nofs = memalloc_nofs_save();
 343         ret = cachefiles_inject_write_error();
 344         if (ret == 0)
 345                 ret = vfs_iocb_iter_write(file, &ki->iocb, iter);
 346         memalloc_nofs_restore(old_nofs);
 347         switch (ret) {
 348         case -EIOCBQUEUED:
 349                 goto in_progress;
 350
 351         case -ERESTARTSYS:
 352         case -ERESTARTNOINTR:
 353         case -ERESTARTNOHAND:
 354         case -ERESTART_RESTARTBLOCK:
 355                 /* There's no easy way to restart the syscall since other AIO's
 356                  * may be already running. Just fail this IO with EINTR.
 357                  */
 358                 ret = -EINTR;
 359                 fallthrough;
 360         default:
 361                 ki->was_async = false;
 362                 cachefiles_write_complete(&ki->iocb, ret);
 363                 if (ret > 0)
 364                         ret = 0;
 365                 break;
 366         }
 367
 368 in_progress:
 369         cachefiles_put_kiocb(ki);
 370         _leave(" = %zd", ret);
 371         return ret;
 372
 373 presubmission_error:
 374         if (term_func)
 375                 term_func(term_func_priv, ret, false);
 376         return ret;
 377 }
 378
 379 /*
 380  * Prepare a read operation, shortening it to a cached/uncached
 381  * boundary as appropriate.
 382  */
 383 static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq,
 384                                                       loff_t i_size)
 385 {
 386         enum cachefiles_prepare_read_trace why;
 387         struct netfs_io_request *rreq = subreq->rreq;
 388         struct netfs_cache_resources *cres = &rreq->cache_resources;
 389         struct cachefiles_object *object;
 390         struct cachefiles_cache *cache;
 391         struct fscache_cookie *cookie = fscache_cres_cookie(cres);
 392         const struct cred *saved_cred;
 393         struct file *file = cachefiles_cres_file(cres);
 394         enum netfs_io_source ret = NETFS_DOWNLOAD_FROM_SERVER;
 395         loff_t off, to;
 396         ino_t ino = file ? file_inode(file)->i_ino : 0;
 397
 398         _enter("%zx @%llx/%llx", subreq->len, subreq->start, i_size);
 399
 400         if (subreq->start >= i_size) {
 401                 ret = NETFS_FILL_WITH_ZEROES;
 402                 why = cachefiles_trace_read_after_eof;
 403                 goto out_no_object;
 404         }
 405
 406         if (test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) {
 407                 __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
 408                 why = cachefiles_trace_read_no_data;
 409                 goto out_no_object;
 410         }
 411
 412         /* The object and the file may be being created in the background. */
 413         if (!file) {
 414                 why = cachefiles_trace_read_no_file;
 415                 if (!fscache_wait_for_operation(cres, FSCACHE_WANT_READ))
 416                         goto out_no_object;
 417                 file = cachefiles_cres_file(cres);
 418                 if (!file)
 419                         goto out_no_object;
 420                 ino = file_inode(file)->i_ino;
 421         }
 422
 423         object = cachefiles_cres_object(cres);
 424         cache = object->volume->cache;
 425         cachefiles_begin_secure(cache, &saved_cred);
 426
 427         off = cachefiles_inject_read_error();
 428         if (off == 0)
 429                 off = vfs_llseek(file, subreq->start, SEEK_DATA);
 430         if (off < 0 && off >= (loff_t)-MAX_ERRNO) {
 431                 if (off == (loff_t)-ENXIO) {
 432                         why = cachefiles_trace_read_seek_nxio;
 433                         goto download_and_store;
 434                 }
 435                 trace_cachefiles_io_error(object, file_inode(file), off,
 436                                           cachefiles_trace_seek_error);
 437                 why = cachefiles_trace_read_seek_error;
 438                 goto out;
 439         }
 440
 441         if (off >= subreq->start + subreq->len) {
 442                 why = cachefiles_trace_read_found_hole;
 443                 goto download_and_store;
 444         }
 445
 446         if (off > subreq->start) {
 447                 off = round_up(off, cache->bsize);
 448                 subreq->len = off - subreq->start;
 449                 why = cachefiles_trace_read_found_part;
 450                 goto download_and_store;
 451         }
 452
 453         to = cachefiles_inject_read_error();
 454         if (to == 0)
 455                 to = vfs_llseek(file, subreq->start, SEEK_HOLE);
 456         if (to < 0 && to >= (loff_t)-MAX_ERRNO) {
 457                 trace_cachefiles_io_error(object, file_inode(file), to,
 458                                           cachefiles_trace_seek_error);
 459                 why = cachefiles_trace_read_seek_error;
 460                 goto out;
 461         }
 462
 463         if (to < subreq->start + subreq->len) {
 464                 if (subreq->start + subreq->len >= i_size)
 465                         to = round_up(to, cache->bsize);
 466                 else
 467                         to = round_down(to, cache->bsize);
 468                 subreq->len = to - subreq->start;
 469         }
 470
 471         why = cachefiles_trace_read_have_data;
 472         ret = NETFS_READ_FROM_CACHE;
 473         goto out;
 474
 475 download_and_store:
 476         __set_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
 477 out:
 478         cachefiles_end_secure(cache, saved_cred);
 479 out_no_object:
 480         trace_cachefiles_prep_read(subreq, ret, why, ino);
 481         return ret;
 482 }
 483
 484 /*
 485  * Prepare for a write to occur.
 486  */
 487 static int __cachefiles_prepare_write(struct netfs_cache_resources *cres,
 488                                       loff_t *_start, size_t *_len, loff_t i_size,
 489                                       bool no_space_allocated_yet)
 490 {
 491         struct cachefiles_object *object = cachefiles_cres_object(cres);
 492         struct cachefiles_cache *cache = object->volume->cache;
 493         struct file *file = cachefiles_cres_file(cres);
 494         loff_t start = *_start, pos;
 495         size_t len = *_len, down;
 496         int ret;
 497
 498         /* Round to DIO size */
 499         down = start - round_down(start, PAGE_SIZE);
 500         *_start = start - down;
 501         *_len = round_up(down + len, PAGE_SIZE);
 502
 503         /* We need to work out whether there's sufficient disk space to perform
 504          * the write - but we can skip that check if we have space already
 505          * allocated.
 506          */
 507         if (no_space_allocated_yet)
 508                 goto check_space;
 509
 510         pos = cachefiles_inject_read_error();
 511         if (pos == 0)
 512                 pos = vfs_llseek(file, *_start, SEEK_DATA);
 513         if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
 514                 if (pos == -ENXIO)
 515                         goto check_space; /* Unallocated tail */
 516                 trace_cachefiles_io_error(object, file_inode(file), pos,
 517                                           cachefiles_trace_seek_error);
 518                 return pos;
 519         }
 520         if ((u64)pos >= (u64)*_start + *_len)
 521                 goto check_space; /* Unallocated region */
 522
 523         /* We have a block that's at least partially filled - if we're low on
 524          * space, we need to see if it's fully allocated.  If it's not, we may
 525          * want to cull it.
 526          */
 527         if (cachefiles_has_space(cache, 0, *_len / PAGE_SIZE,
 528                                  cachefiles_has_space_check) == 0)
 529                 return 0; /* Enough space to simply overwrite the whole block */
 530
 531         pos = cachefiles_inject_read_error();
 532         if (pos == 0)
 533                 pos = vfs_llseek(file, *_start, SEEK_HOLE);
 534         if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
 535                 trace_cachefiles_io_error(object, file_inode(file), pos,
 536                                           cachefiles_trace_seek_error);
 537                 return pos;
 538         }
 539         if ((u64)pos >= (u64)*_start + *_len)
 540                 return 0; /* Fully allocated */
 541
 542         /* Partially allocated, but insufficient space: cull. */
 543         fscache_count_no_write_space();
 544         ret = cachefiles_inject_remove_error();
 545         if (ret == 0)
 546                 ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
 547                                     *_start, *_len);
 548         if (ret < 0) {
 549                 trace_cachefiles_io_error(object, file_inode(file), ret,
 550                                           cachefiles_trace_fallocate_error);
 551                 cachefiles_io_error_obj(object,
 552                                         "CacheFiles: fallocate failed (%d)\n", ret);
 553                 ret = -EIO;
 554         }
 555
 556         return ret;
 557
 558 check_space:
 559         return cachefiles_has_space(cache, 0, *_len / PAGE_SIZE,
 560                                     cachefiles_has_space_for_write);
 561 }
 562
 563 static int cachefiles_prepare_write(struct netfs_cache_resources *cres,
 564                                     loff_t *_start, size_t *_len, loff_t i_size,
 565                                     bool no_space_allocated_yet)
 566 {
 567         struct cachefiles_object *object = cachefiles_cres_object(cres);
 568         struct cachefiles_cache *cache = object->volume->cache;
 569         const struct cred *saved_cred;
 570         int ret;
 571
 572         if (!cachefiles_cres_file(cres)) {
 573                 if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE))
 574                         return -ENOBUFS;
 575                 if (!cachefiles_cres_file(cres))
 576                         return -ENOBUFS;
 577         }
 578
 579         cachefiles_begin_secure(cache, &saved_cred);
 580         ret = __cachefiles_prepare_write(cres, _start, _len, i_size,
 581                                          no_space_allocated_yet);
 582         cachefiles_end_secure(cache, saved_cred);
 583         return ret;
 584 }
 585
 586 /*
 587  * Clean up an operation.
 588  */
 589 static void cachefiles_end_operation(struct netfs_cache_resources *cres)
 590 {
 591         struct file *file = cachefiles_cres_file(cres);
 592
 593         if (file)
 594                 fput(file);
 595         fscache_end_cookie_access(fscache_cres_cookie(cres), fscache_access_io_end);
 596 }
 597
 598 static const struct netfs_cache_ops cachefiles_netfs_cache_ops = {
 599         .end_operation          = cachefiles_end_operation,
 600         .read                   = cachefiles_read,
 601         .write                  = cachefiles_write,
 602         .prepare_read           = cachefiles_prepare_read,
 603         .prepare_write          = cachefiles_prepare_write,
 604         .query_occupancy        = cachefiles_query_occupancy,
 605 };
 606
 607 /*
 608  * Open the cache file when beginning a cache operation.
 609  */
 610 bool cachefiles_begin_operation(struct netfs_cache_resources *cres,
 611                                 enum fscache_want_state want_state)
 612 {
 613         struct cachefiles_object *object = cachefiles_cres_object(cres);
 614
 615         if (!cachefiles_cres_file(cres)) {
 616                 cres->ops = &cachefiles_netfs_cache_ops;
 617                 if (object->file) {
 618                         spin_lock(&object->lock);
 619                         if (!cres->cache_priv2 && object->file)
 620                                 cres->cache_priv2 = get_file(object->file);
 621                         spin_unlock(&object->lock);
 622                 }
 623         }
 624
 625         if (!cachefiles_cres_file(cres) && want_state != FSCACHE_WANT_PARAMS) {
 626                 pr_err("failed to get cres->file\n");
 627                 return false;
 628         }
 629
 630         return true;
 631 }