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