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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
20static 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 */
49ssize_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 bool open_for_read;
61 bool 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
72populate_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
271out:
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
282int 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
323static 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);
335out:
336 up_read(&file_inode(iocb->ki_filp)->i_rwsem);
337 return ret;
338}
339
340static 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);
355out:
356 up_read(&inode->i_rwsem);
357 return ret;
358}
359
360static 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
376static 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
392static 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 */
401static int orangefs_file_mmap_prepare(struct vm_area_desc *desc)
402{
403 struct file *file = desc->file;
404 int ret;
405
406 ret = orangefs_revalidate_mapping(file_inode(file));
407 if (ret)
408 return ret;
409
410 gossip_debug(GOSSIP_FILE_DEBUG,
411 "orangefs_file_mmap: called on %pD\n", file);
412
413 /* set the sequential readahead hint */
414 vma_desc_set_flags(desc, VMA_SEQ_READ_BIT);
415 vma_desc_clear_flags(desc, VMA_RAND_READ_BIT);
416
417 file_accessed(file);
418 desc->vm_ops = &orangefs_file_vm_ops;
419 return 0;
420}
421
422#define mapping_nrpages(idata) ((idata)->nrpages)
423
424/*
425 * Called to notify the module that there are no more references to
426 * this file (i.e. no processes have it open).
427 *
428 * \note Not called when each file is closed.
429 */
430static int orangefs_file_release(struct inode *inode, struct file *file)
431{
432 gossip_debug(GOSSIP_FILE_DEBUG,
433 "orangefs_file_release: called on %pD\n",
434 file);
435
436 /*
437 * remove all associated inode pages from the page cache and
438 * readahead cache (if any); this forces an expensive refresh of
439 * data for the next caller of mmap (or 'get_block' accesses)
440 */
441 if (mapping_nrpages(file->f_mapping)) {
442 if (orangefs_features & ORANGEFS_FEATURE_READAHEAD) {
443 gossip_debug(GOSSIP_INODE_DEBUG,
444 "calling flush_racache on %pU\n",
445 get_khandle_from_ino(inode));
446 flush_racache(inode);
447 gossip_debug(GOSSIP_INODE_DEBUG,
448 "flush_racache finished\n");
449 }
450
451 }
452 return 0;
453}
454
455/*
456 * Push all data for a specific file onto permanent storage.
457 */
458static int orangefs_fsync(struct file *file,
459 loff_t start,
460 loff_t end,
461 int datasync)
462{
463 int ret;
464 struct orangefs_inode_s *orangefs_inode =
465 ORANGEFS_I(file_inode(file));
466 struct orangefs_kernel_op_s *new_op = NULL;
467
468 ret = filemap_write_and_wait_range(file_inode(file)->i_mapping,
469 start, end);
470 if (ret < 0)
471 return ret;
472
473 new_op = op_alloc(ORANGEFS_VFS_OP_FSYNC);
474 if (!new_op)
475 return -ENOMEM;
476 new_op->upcall.req.fsync.refn = orangefs_inode->refn;
477
478 ret = service_operation(new_op,
479 "orangefs_fsync",
480 get_interruptible_flag(file_inode(file)));
481
482 gossip_debug(GOSSIP_FILE_DEBUG,
483 "orangefs_fsync got return value of %d\n",
484 ret);
485
486 op_release(new_op);
487 return ret;
488}
489
490/*
491 * Change the file pointer position for an instance of an open file.
492 *
493 * \note If .llseek is overriden, we must acquire lock as described in
494 * Documentation/filesystems/locking.rst.
495 *
496 * Future upgrade could support SEEK_DATA and SEEK_HOLE but would
497 * require much changes to the FS
498 */
499static loff_t orangefs_file_llseek(struct file *file, loff_t offset, int origin)
500{
501 int ret = -EINVAL;
502 struct inode *inode = file_inode(file);
503
504 if (origin == SEEK_END) {
505 /*
506 * revalidate the inode's file size.
507 * NOTE: We are only interested in file size here,
508 * so we set mask accordingly.
509 */
510 ret = orangefs_inode_getattr(file->f_mapping->host,
511 ORANGEFS_GETATTR_SIZE);
512 if (ret == -ESTALE)
513 ret = -EIO;
514 if (ret) {
515 gossip_debug(GOSSIP_FILE_DEBUG,
516 "%s:%s:%d calling make bad inode\n",
517 __FILE__,
518 __func__,
519 __LINE__);
520 return ret;
521 }
522 }
523
524 gossip_debug(GOSSIP_FILE_DEBUG,
525 "orangefs_file_llseek: offset is %ld | origin is %d"
526 " | inode size is %lu\n",
527 (long)offset,
528 origin,
529 (unsigned long)i_size_read(inode));
530
531 return generic_file_llseek(file, offset, origin);
532}
533
534/*
535 * Support local locks (locks that only this kernel knows about)
536 * if Orangefs was mounted -o local_lock.
537 */
538static int orangefs_lock(struct file *filp, int cmd, struct file_lock *fl)
539{
540 int rc = -EINVAL;
541
542 if (ORANGEFS_SB(file_inode(filp)->i_sb)->flags & ORANGEFS_OPT_LOCAL_LOCK) {
543 if (cmd == F_GETLK) {
544 rc = 0;
545 posix_test_lock(filp, fl);
546 } else {
547 rc = posix_lock_file(filp, fl, NULL);
548 }
549 }
550
551 return rc;
552}
553
554static int orangefs_flush(struct file *file, fl_owner_t id)
555{
556 /*
557 * This is vfs_fsync_range(file, 0, LLONG_MAX, 0) without the
558 * service_operation in orangefs_fsync.
559 *
560 * Do not send fsync to OrangeFS server on a close. Do send fsync
561 * on an explicit fsync call. This duplicates historical OrangeFS
562 * behavior.
563 */
564 int r;
565
566 r = filemap_write_and_wait_range(file->f_mapping, 0, LLONG_MAX);
567 if (r > 0)
568 return 0;
569 else
570 return r;
571}
572
573/** ORANGEFS implementation of VFS file operations */
574const struct file_operations orangefs_file_operations = {
575 .llseek = orangefs_file_llseek,
576 .read_iter = orangefs_file_read_iter,
577 .write_iter = orangefs_file_write_iter,
578 .lock = orangefs_lock,
579 .mmap_prepare = orangefs_file_mmap_prepare,
580 .open = generic_file_open,
581 .splice_read = orangefs_file_splice_read,
582 .splice_write = iter_file_splice_write,
583 .flush = orangefs_flush,
584 .release = orangefs_file_release,
585 .fsync = orangefs_fsync,
586 .setlease = generic_setlease,
587};