fs/orangefs/file.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * (C) 2001 Clemson University and The University of Chicago
   4  * Copyright 2018 Omnibond Systems, L.L.C.
   5  *
   6  * See COPYING in top-level directory.
   7  */
   8
   9 /*
  10  *  Linux VFS file operations.
  11  */
  12
  13 #include "protocol.h"
  14 #include "orangefs-kernel.h"
  15 #include "orangefs-bufmap.h"
  16 #include <linux/fs.h>
  17 #include <linux/filelock.h>
  18 #include <linux/pagemap.h>
  19
  20 static int flush_racache(struct inode *inode)
  21 {
  22         struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
  23         struct orangefs_kernel_op_s *new_op;
  24         int ret;
  25
  26         gossip_debug(GOSSIP_UTILS_DEBUG,
  27             "%s: %pU: Handle is %pU | fs_id %d\n", __func__,
  28             get_khandle_from_ino(inode), &orangefs_inode->refn.khandle,
  29             orangefs_inode->refn.fs_id);
  30
  31         new_op = op_alloc(ORANGEFS_VFS_OP_RA_FLUSH);
  32         if (!new_op)
  33                 return -ENOMEM;
  34         new_op->upcall.req.ra_cache_flush.refn = orangefs_inode->refn;
  35
  36         ret = service_operation(new_op, "orangefs_flush_racache",
  37             get_interruptible_flag(inode));
  38
  39         gossip_debug(GOSSIP_UTILS_DEBUG, "%s: got return value of %d\n",
  40             __func__, ret);
  41
  42         op_release(new_op);
  43         return ret;
  44 }
  45
  46 /*
  47  * Post and wait for the I/O upcall to finish
  48  */
  49 ssize_t wait_for_direct_io(enum ORANGEFS_io_type type, struct inode *inode,
  50         loff_t *offset, struct iov_iter *iter, size_t total_size,
  51         loff_t readahead_size, struct orangefs_write_range *wr,
  52         int *index_return, struct file *file)
  53 {
  54         struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
  55         struct orangefs_khandle *handle = &orangefs_inode->refn.khandle;
  56         struct orangefs_kernel_op_s *new_op = NULL;
  57         int buffer_index;
  58         ssize_t ret;
  59         size_t copy_amount;
  60         int open_for_read;
  61         int open_for_write;
  62
  63         new_op = op_alloc(ORANGEFS_VFS_OP_FILE_IO);
  64         if (!new_op)
  65                 return -ENOMEM;
  66
  67         /* synchronous I/O */
  68         new_op->upcall.req.io.readahead_size = readahead_size;
  69         new_op->upcall.req.io.io_type = type;
  70         new_op->upcall.req.io.refn = orangefs_inode->refn;
  71
  72 populate_shared_memory:
  73         /* get a shared buffer index */
  74         buffer_index = orangefs_bufmap_get();
  75         if (buffer_index < 0) {
  76                 ret = buffer_index;
  77                 gossip_debug(GOSSIP_FILE_DEBUG,
  78                              "%s: orangefs_bufmap_get failure (%zd)\n",
  79                              __func__, ret);
  80                 goto out;
  81         }
  82         gossip_debug(GOSSIP_FILE_DEBUG,
  83                      "%s(%pU): GET op %p -> buffer_index %d\n",
  84                      __func__,
  85                      handle,
  86                      new_op,
  87                      buffer_index);
  88
  89         new_op->uses_shared_memory = 1;
  90         new_op->upcall.req.io.buf_index = buffer_index;
  91         new_op->upcall.req.io.count = total_size;
  92         new_op->upcall.req.io.offset = *offset;
  93         if (type == ORANGEFS_IO_WRITE && wr) {
  94                 new_op->upcall.uid = from_kuid(&init_user_ns, wr->uid);
  95                 new_op->upcall.gid = from_kgid(&init_user_ns, wr->gid);
  96         }
  97         /*
  98          * Orangefs has no open, and orangefs checks file permissions
  99          * on each file access. Posix requires that file permissions
 100          * be checked on open and nowhere else. Orangefs-through-the-kernel
 101          * needs to seem posix compliant.
 102          *
 103          * The VFS opens files, even if the filesystem provides no
 104          * method. We can see if a file was successfully opened for
 105          * read and or for write by looking at file->f_mode.
 106          *
 107          * When writes are flowing from the page cache, file is no
 108          * longer available. We can trust the VFS to have checked
 109          * file->f_mode before writing to the page cache.
 110          *
 111          * The mode of a file might change between when it is opened
 112          * and IO commences, or it might be created with an arbitrary mode.
 113          *
 114          * We'll make sure we don't hit EACCES during the IO stage by
 115          * using UID 0. Some of the time we have access without changing
 116          * to UID 0 - how to check?
 117          */
 118         if (file) {
 119                 open_for_write = file->f_mode & FMODE_WRITE;
 120                 open_for_read = file->f_mode & FMODE_READ;
 121         } else {
 122                 open_for_write = 1;
 123                 open_for_read = 0; /* not relevant? */
 124         }
 125         if ((type == ORANGEFS_IO_WRITE) && open_for_write)
 126                 new_op->upcall.uid = 0;
 127         if ((type == ORANGEFS_IO_READ) && open_for_read)
 128                 new_op->upcall.uid = 0;
 129
 130         gossip_debug(GOSSIP_FILE_DEBUG,
 131                      "%s(%pU): offset: %llu total_size: %zd\n",
 132                      __func__,
 133                      handle,
 134                      llu(*offset),
 135                      total_size);
 136         /*
 137          * Stage 1: copy the buffers into client-core's address space
 138          */
 139         if (type == ORANGEFS_IO_WRITE && total_size) {
 140                 ret = orangefs_bufmap_copy_from_iovec(iter, buffer_index,
 141                     total_size);
 142                 if (ret < 0) {
 143                         gossip_err("%s: Failed to copy-in buffers. Please make sure that the pvfs2-client is running. %ld\n",
 144                             __func__, (long)ret);
 145                         goto out;
 146                 }
 147         }
 148
 149         gossip_debug(GOSSIP_FILE_DEBUG,
 150                      "%s(%pU): Calling post_io_request with tag (%llu)\n",
 151                      __func__,
 152                      handle,
 153                      llu(new_op->tag));
 154
 155         /* Stage 2: Service the I/O operation */
 156         ret = service_operation(new_op,
 157                                 type == ORANGEFS_IO_WRITE ?
 158                                         "file_write" :
 159                                         "file_read",
 160                                 get_interruptible_flag(inode));
 161
 162         /*
 163          * If service_operation() returns -EAGAIN #and# the operation was
 164          * purged from orangefs_request_list or htable_ops_in_progress, then
 165          * we know that the client was restarted, causing the shared memory
 166          * area to be wiped clean.  To restart a  write operation in this
 167          * case, we must re-copy the data from the user's iovec to a NEW
 168          * shared memory location. To restart a read operation, we must get
 169          * a new shared memory location.
 170          */
 171         if (ret == -EAGAIN && op_state_purged(new_op)) {
 172                 orangefs_bufmap_put(buffer_index);
 173                 if (type == ORANGEFS_IO_WRITE)
 174                         iov_iter_revert(iter, total_size);
 175                 gossip_debug(GOSSIP_FILE_DEBUG,
 176                              "%s:going to repopulate_shared_memory.\n",
 177                              __func__);
 178                 goto populate_shared_memory;
 179         }
 180
 181         if (ret < 0) {
 182                 if (ret == -EINTR) {
 183                         /*
 184                          * We can't return EINTR if any data was written,
 185                          * it's not POSIX. It is minimally acceptable
 186                          * to give a partial write, the way NFS does.
 187                          *
 188                          * It would be optimal to return all or nothing,
 189                          * but if a userspace write is bigger than
 190                          * an IO buffer, and the interrupt occurs
 191                          * between buffer writes, that would not be
 192                          * possible.
 193                          */
 194                         switch (new_op->op_state - OP_VFS_STATE_GIVEN_UP) {
 195                         /*
 196                          * If the op was waiting when the interrupt
 197                          * occurred, then the client-core did not
 198                          * trigger the write.
 199                          */
 200                         case OP_VFS_STATE_WAITING:
 201                                 if (*offset == 0)
 202                                         ret = -EINTR;
 203                                 else
 204                                         ret = 0;
 205                                 break;
 206                         /*
 207                          * If the op was in progress when the interrupt
 208                          * occurred, then the client-core was able to
 209                          * trigger the write.
 210                          */
 211                         case OP_VFS_STATE_INPROGR:
 212                                 if (type == ORANGEFS_IO_READ)
 213                                         ret = -EINTR;
 214                                 else
 215                                         ret = total_size;
 216                                 break;
 217                         default:
 218                                 gossip_err("%s: unexpected op state :%d:.\n",
 219                                            __func__,
 220                                            new_op->op_state);
 221                                 ret = 0;
 222                                 break;
 223                         }
 224                         gossip_debug(GOSSIP_FILE_DEBUG,
 225                                      "%s: got EINTR, state:%d: %p\n",
 226                                      __func__,
 227                                      new_op->op_state,
 228                                      new_op);
 229                 } else {
 230                         gossip_err("%s: error in %s handle %pU, returning %zd\n",
 231                                 __func__,
 232                                 type == ORANGEFS_IO_READ ?
 233                                         "read from" : "write to",
 234                                 handle, ret);
 235                 }
 236                 if (orangefs_cancel_op_in_progress(new_op))
 237                         return ret;
 238
 239                 goto out;
 240         }
 241
 242         /*
 243          * Stage 3: Post copy buffers from client-core's address space
 244          */
 245         if (type == ORANGEFS_IO_READ && new_op->downcall.resp.io.amt_complete) {
 246                 /*
 247                  * NOTE: the iovector can either contain addresses which
 248                  *       can futher be kernel-space or user-space addresses.
 249                  *       or it can pointers to struct page's
 250                  */
 251
 252                 copy_amount = new_op->downcall.resp.io.amt_complete;
 253
 254                 ret = orangefs_bufmap_copy_to_iovec(iter, buffer_index,
 255                         copy_amount);
 256                 if (ret < 0) {
 257                         gossip_err("%s: Failed to copy-out buffers. Please make sure that the pvfs2-client is running (%ld)\n",
 258                             __func__, (long)ret);
 259                         goto out;
 260                 }
 261         }
 262         gossip_debug(GOSSIP_FILE_DEBUG,
 263             "%s(%pU): Amount %s, returned by the sys-io call:%d\n",
 264             __func__,
 265             handle,
 266             type == ORANGEFS_IO_READ ?  "read" : "written",
 267             (int)new_op->downcall.resp.io.amt_complete);
 268
 269         ret = new_op->downcall.resp.io.amt_complete;
 270
 271 out:
 272         if (buffer_index >= 0) {
 273                 orangefs_bufmap_put(buffer_index);
 274                 gossip_debug(GOSSIP_FILE_DEBUG,
 275                         "%s(%pU): PUT buffer_index %d\n",
 276                         __func__, handle, buffer_index);
 277         }
 278         op_release(new_op);
 279         return ret;
 280 }
 281
 282 int orangefs_revalidate_mapping(struct inode *inode)
 283 {
 284         struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
 285         struct address_space *mapping = inode->i_mapping;
 286         unsigned long *bitlock = &orangefs_inode->bitlock;
 287         int ret;
 288
 289         while (1) {
 290                 ret = wait_on_bit(bitlock, 1, TASK_KILLABLE);
 291                 if (ret)
 292                         return ret;
 293                 spin_lock(&inode->i_lock);
 294                 if (test_bit(1, bitlock)) {
 295                         spin_unlock(&inode->i_lock);
 296                         continue;
 297                 }
 298                 if (!time_before(jiffies, orangefs_inode->mapping_time))
 299                         break;
 300                 spin_unlock(&inode->i_lock);
 301                 return 0;
 302         }
 303
 304         set_bit(1, bitlock);
 305         smp_wmb();
 306         spin_unlock(&inode->i_lock);
 307
 308         unmap_mapping_range(mapping, 0, 0, 0);
 309         ret = filemap_write_and_wait(mapping);
 310         if (!ret)
 311                 ret = invalidate_inode_pages2(mapping);
 312
 313         orangefs_inode->mapping_time = jiffies +
 314             orangefs_cache_timeout_msecs*HZ/1000;
 315
 316         clear_bit(1, bitlock);
 317         smp_mb__after_atomic();
 318         wake_up_bit(bitlock, 1);
 319
 320         return ret;
 321 }
 322
 323 static ssize_t orangefs_file_read_iter(struct kiocb *iocb,
 324     struct iov_iter *iter)
 325 {
 326         int ret;
 327         orangefs_stats.reads++;
 328
 329         down_read(&file_inode(iocb->ki_filp)->i_rwsem);
 330         ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
 331         if (ret)
 332                 goto out;
 333
 334         ret = generic_file_read_iter(iocb, iter);
 335 out:
 336         up_read(&file_inode(iocb->ki_filp)->i_rwsem);
 337         return ret;
 338 }
 339
 340 static ssize_t orangefs_file_splice_read(struct file *in, loff_t *ppos,
 341                                          struct pipe_inode_info *pipe,
 342                                          size_t len, unsigned int flags)
 343 {
 344         struct inode *inode = file_inode(in);
 345         ssize_t ret;
 346
 347         orangefs_stats.reads++;
 348
 349         down_read(&inode->i_rwsem);
 350         ret = orangefs_revalidate_mapping(inode);
 351         if (ret)
 352                 goto out;
 353
 354         ret = filemap_splice_read(in, ppos, pipe, len, flags);
 355 out:
 356         up_read(&inode->i_rwsem);
 357         return ret;
 358 }
 359
 360 static ssize_t orangefs_file_write_iter(struct kiocb *iocb,
 361     struct iov_iter *iter)
 362 {
 363         int ret;
 364         orangefs_stats.writes++;
 365
 366         if (iocb->ki_pos > i_size_read(file_inode(iocb->ki_filp))) {
 367                 ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
 368                 if (ret)
 369                         return ret;
 370         }
 371
 372         ret = generic_file_write_iter(iocb, iter);
 373         return ret;
 374 }
 375
 376 static vm_fault_t orangefs_fault(struct vm_fault *vmf)
 377 {
 378         struct file *file = vmf->vma->vm_file;
 379         int ret;
 380         ret = orangefs_inode_getattr(file->f_mapping->host,
 381             ORANGEFS_GETATTR_SIZE);
 382         if (ret == -ESTALE)
 383                 ret = -EIO;
 384         if (ret) {
 385                 gossip_err("%s: orangefs_inode_getattr failed, "
 386                     "ret:%d:.\n", __func__, ret);
 387                 return VM_FAULT_SIGBUS;
 388         }
 389         return filemap_fault(vmf);
 390 }
 391
 392 static const struct vm_operations_struct orangefs_file_vm_ops = {
 393         .fault = orangefs_fault,
 394         .map_pages = filemap_map_pages,
 395         .page_mkwrite = orangefs_page_mkwrite,
 396 };
 397
 398 /*
 399  * Memory map a region of a file.
 400  */
 401 static int orangefs_file_mmap(struct file *file, struct vm_area_struct *vma)
 402 {
 403         int ret;
 404
 405         ret = orangefs_revalidate_mapping(file_inode(file));
 406         if (ret)
 407                 return ret;
 408
 409         gossip_debug(GOSSIP_FILE_DEBUG,
 410                      "orangefs_file_mmap: called on %pD\n", file);
 411
 412         /* set the sequential readahead hint */
 413         vm_flags_mod(vma, VM_SEQ_READ, VM_RAND_READ);
 414
 415         file_accessed(file);
 416         vma->vm_ops = &orangefs_file_vm_ops;
 417         return 0;
 418 }
 419
 420 #define mapping_nrpages(idata) ((idata)->nrpages)
 421
 422 /*
 423  * Called to notify the module that there are no more references to
 424  * this file (i.e. no processes have it open).
 425  *
 426  * \note Not called when each file is closed.
 427  */
 428 static int orangefs_file_release(struct inode *inode, struct file *file)
 429 {
 430         gossip_debug(GOSSIP_FILE_DEBUG,
 431                      "orangefs_file_release: called on %pD\n",
 432                      file);
 433
 434         /*
 435          * remove all associated inode pages from the page cache and
 436          * readahead cache (if any); this forces an expensive refresh of
 437          * data for the next caller of mmap (or 'get_block' accesses)
 438          */
 439         if (mapping_nrpages(file->f_mapping)) {
 440                 if (orangefs_features & ORANGEFS_FEATURE_READAHEAD) {
 441                         gossip_debug(GOSSIP_INODE_DEBUG,
 442                             "calling flush_racache on %pU\n",
 443                             get_khandle_from_ino(inode));
 444                         flush_racache(inode);
 445                         gossip_debug(GOSSIP_INODE_DEBUG,
 446                             "flush_racache finished\n");
 447                 }
 448
 449         }
 450         return 0;
 451 }
 452
 453 /*
 454  * Push all data for a specific file onto permanent storage.
 455  */
 456 static int orangefs_fsync(struct file *file,
 457                        loff_t start,
 458                        loff_t end,
 459                        int datasync)
 460 {
 461         int ret;
 462         struct orangefs_inode_s *orangefs_inode =
 463                 ORANGEFS_I(file_inode(file));
 464         struct orangefs_kernel_op_s *new_op = NULL;
 465
 466         ret = filemap_write_and_wait_range(file_inode(file)->i_mapping,
 467             start, end);
 468         if (ret < 0)
 469                 return ret;
 470
 471         new_op = op_alloc(ORANGEFS_VFS_OP_FSYNC);
 472         if (!new_op)
 473                 return -ENOMEM;
 474         new_op->upcall.req.fsync.refn = orangefs_inode->refn;
 475
 476         ret = service_operation(new_op,
 477                         "orangefs_fsync",
 478                         get_interruptible_flag(file_inode(file)));
 479
 480         gossip_debug(GOSSIP_FILE_DEBUG,
 481                      "orangefs_fsync got return value of %d\n",
 482                      ret);
 483
 484         op_release(new_op);
 485         return ret;
 486 }
 487
 488 /*
 489  * Change the file pointer position for an instance of an open file.
 490  *
 491  * \note If .llseek is overriden, we must acquire lock as described in
 492  *       Documentation/filesystems/locking.rst.
 493  *
 494  * Future upgrade could support SEEK_DATA and SEEK_HOLE but would
 495  * require much changes to the FS
 496  */
 497 static loff_t orangefs_file_llseek(struct file *file, loff_t offset, int origin)
 498 {
 499         int ret = -EINVAL;
 500         struct inode *inode = file_inode(file);
 501
 502         if (origin == SEEK_END) {
 503                 /*
 504                  * revalidate the inode's file size.
 505                  * NOTE: We are only interested in file size here,
 506                  * so we set mask accordingly.
 507                  */
 508                 ret = orangefs_inode_getattr(file->f_mapping->host,
 509                     ORANGEFS_GETATTR_SIZE);
 510                 if (ret == -ESTALE)
 511                         ret = -EIO;
 512                 if (ret) {
 513                         gossip_debug(GOSSIP_FILE_DEBUG,
 514                                      "%s:%s:%d calling make bad inode\n",
 515                                      __FILE__,
 516                                      __func__,
 517                                      __LINE__);
 518                         return ret;
 519                 }
 520         }
 521
 522         gossip_debug(GOSSIP_FILE_DEBUG,
 523                      "orangefs_file_llseek: offset is %ld | origin is %d"
 524                      " | inode size is %lu\n",
 525                      (long)offset,
 526                      origin,
 527                      (unsigned long)i_size_read(inode));
 528
 529         return generic_file_llseek(file, offset, origin);
 530 }
 531
 532 /*
 533  * Support local locks (locks that only this kernel knows about)
 534  * if Orangefs was mounted -o local_lock.
 535  */
 536 static int orangefs_lock(struct file *filp, int cmd, struct file_lock *fl)
 537 {
 538         int rc = -EINVAL;
 539
 540         if (ORANGEFS_SB(file_inode(filp)->i_sb)->flags & ORANGEFS_OPT_LOCAL_LOCK) {
 541                 if (cmd == F_GETLK) {
 542                         rc = 0;
 543                         posix_test_lock(filp, fl);
 544                 } else {
 545                         rc = posix_lock_file(filp, fl, NULL);
 546                 }
 547         }
 548
 549         return rc;
 550 }
 551
 552 static int orangefs_flush(struct file *file, fl_owner_t id)
 553 {
 554         /*
 555          * This is vfs_fsync_range(file, 0, LLONG_MAX, 0) without the
 556          * service_operation in orangefs_fsync.
 557          *
 558          * Do not send fsync to OrangeFS server on a close.  Do send fsync
 559          * on an explicit fsync call.  This duplicates historical OrangeFS
 560          * behavior.
 561          */
 562         int r;
 563
 564         r = filemap_write_and_wait_range(file->f_mapping, 0, LLONG_MAX);
 565         if (r > 0)
 566                 return 0;
 567         else
 568                 return r;
 569 }
 570
 571 /** ORANGEFS implementation of VFS file operations */
 572 const struct file_operations orangefs_file_operations = {
 573         .llseek         = orangefs_file_llseek,
 574         .read_iter      = orangefs_file_read_iter,
 575         .write_iter     = orangefs_file_write_iter,
 576         .lock           = orangefs_lock,
 577         .mmap           = orangefs_file_mmap,
 578         .open           = generic_file_open,
 579         .splice_read    = orangefs_file_splice_read,
 580         .splice_write   = iter_file_splice_write,
 581         .flush          = orangefs_flush,
 582         .release        = orangefs_file_release,
 583         .fsync          = orangefs_fsync,
 584 };