VirtualBox

source: vbox/trunk/src/VBox/Additions/linux/sharedfolders/regops.c@ 88716

Last change on this file since 88716 was 88716, checked in by vboxsync, 3 years ago

linux/vboxsf: Document 5.10+ adjustments. We cannot provide both regular and iterative read/write methods because the kernel thinks there might be semantics differences and refuses to do in-kernel reads/writes to our FS. For in-kernel reads/writes there must only be .write_iter/.read_iter now. Restored removed newlines (fingers off my newlines). Rebalanced newlines (multi-function #ifdefs have newline before and after). bugref:9994
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File size: 146.7 KB
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1/* $Id: regops.c 88716 2021-04-26 20:41:51Z vboxsync $ */
2/** @file
3 * vboxsf - VBox Linux Shared Folders VFS, regular file inode and file operations.
4 */
5
6/*
7 * Copyright (C) 2006-2020 Oracle Corporation
8 *
9 * Permission is hereby granted, free of charge, to any person
10 * obtaining a copy of this software and associated documentation
11 * files (the "Software"), to deal in the Software without
12 * restriction, including without limitation the rights to use,
13 * copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the
15 * Software is furnished to do so, subject to the following
16 * conditions:
17 *
18 * The above copyright notice and this permission notice shall be
19 * included in all copies or substantial portions of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
22 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
23 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
24 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
25 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
26 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28 * OTHER DEALINGS IN THE SOFTWARE.
29 */
30
31
32/*********************************************************************************************************************************
33* Header Files *
34*********************************************************************************************************************************/
35#include "vfsmod.h"
36#include <linux/uio.h>
37#if RTLNX_VER_MIN(2,5,32)
38# include <linux/aio.h> /* struct kiocb before 4.1 */
39#endif
40#if RTLNX_VER_MIN(2,5,12)
41# include <linux/buffer_head.h>
42#endif
43#if RTLNX_VER_RANGE(2,5,12, 2,6,31)
44# include <linux/writeback.h>
45#endif
46#if RTLNX_VER_RANGE(2,6,23, 3,16,0)
47# include <linux/splice.h>
48#endif
49#if RTLNX_VER_RANGE(2,6,17, 2,6,23)
50# include <linux/pipe_fs_i.h>
51#endif
52#if RTLNX_VER_MIN(2,4,10)
53# include <linux/swap.h> /* for mark_page_accessed */
54#endif
55#include <iprt/err.h>
56
57#if RTLNX_VER_MAX(2,6,18)
58# define SEEK_END 2
59#endif
60
61#if RTLNX_VER_MAX(3,16,0)
62# define iter_is_iovec(a_pIter) ( !((a_pIter)->type & ITER_KVEC) )
63#elif RTLNX_VER_MAX(3,19,0)
64# define iter_is_iovec(a_pIter) ( !((a_pIter)->type & (ITER_KVEC | ITER_BVEC)) )
65#endif
66
67#if RTLNX_VER_MAX(4,17,0)
68# define vm_fault_t int
69#endif
70
71#if RTLNX_VER_MAX(2,5,20)
72# define pgoff_t unsigned long
73#endif
74
75#if RTLNX_VER_MAX(2,5,12)
76# define PageUptodate(a_pPage) Page_Uptodate(a_pPage)
77#endif
78
79
80/*********************************************************************************************************************************
81* Structures and Typedefs *
82*********************************************************************************************************************************/
83#if RTLNX_VER_MAX(3,16,0)
84struct vbsf_iov_iter {
85 unsigned int type;
86 unsigned int v_write : 1;
87 size_t iov_offset;
88 size_t nr_segs;
89 struct iovec const *iov;
90# ifdef VBOX_STRICT
91 struct iovec const *iov_org;
92 size_t nr_segs_org;
93# endif
94};
95# ifdef VBOX_STRICT
96# define VBSF_IOV_ITER_INITIALIZER(a_cSegs, a_pIov, a_fWrite) \
97 { vbsf_iov_iter_detect_type(a_pIov, a_cSegs), a_fWrite, 0, a_cSegs, a_pIov, a_pIov, a_cSegs }
98# else
99# define VBSF_IOV_ITER_INITIALIZER(a_cSegs, a_pIov, a_fWrite) \
100 { vbsf_iov_iter_detect_type(a_pIov, a_cSegs), a_fWrite, 0, a_cSegs, a_pIov }
101# endif
102# define ITER_KVEC 1
103# define iov_iter vbsf_iov_iter
104#endif
105
106#if RTLNX_VER_MIN(2,6,19)
107/** Used by vbsf_iter_lock_pages() to keep the first page of the next segment. */
108struct vbsf_iter_stash {
109 struct page *pPage;
110 size_t off;
111 size_t cb;
112# if RTLNX_VER_MAX(4,11,0)
113 size_t offFromEnd;
114 struct iov_iter Copy;
115# endif
116};
117#endif /* >= 3.16.0 */
118/** Initializer for struct vbsf_iter_stash. */
119#if RTLNX_VER_MIN(4,11,0)
120# define VBSF_ITER_STASH_INITIALIZER { NULL, 0 }
121#else
122# define VBSF_ITER_STASH_INITIALIZER { NULL, 0, ~(size_t)0 }
123#endif
124
125
126/*********************************************************************************************************************************
127* Internal Functions *
128*********************************************************************************************************************************/
129DECLINLINE(void) vbsf_put_page(struct page *pPage);
130static void vbsf_unlock_user_pages(struct page **papPages, size_t cPages, bool fSetDirty, bool fLockPgHack);
131static void vbsf_reg_write_sync_page_cache(struct address_space *mapping, loff_t offFile, uint32_t cbRange,
132 uint8_t const *pbSrcBuf, struct page **papSrcPages,
133 uint32_t offSrcPage, size_t cSrcPages);
134
135
136/*********************************************************************************************************************************
137* Provide more recent uio.h functionality to older kernels. *
138*********************************************************************************************************************************/
139#if RTLNX_VER_RANGE(2,6,19, 3,16,0)
140
141/**
142 * Detects the vector type.
143 */
144static int vbsf_iov_iter_detect_type(struct iovec const *paIov, size_t cSegs)
145{
146 /* Check the first segment with a non-zero length. */
147 while (cSegs-- > 0) {
148 if (paIov->iov_len > 0) {
149 if (access_ok(VERIFY_READ, paIov->iov_base, paIov->iov_len))
150#if RTLNX_VER_MIN(5,10,0)
151 return (uintptr_t)paIov->iov_base >= TASK_SIZE_MAX ? ITER_KVEC : 0;
152#else
153 return (uintptr_t)paIov->iov_base >= USER_DS.seg ? ITER_KVEC : 0;
154#endif
155 AssertMsgFailed(("%p LB %#zx\n", paIov->iov_base, paIov->iov_len));
156 break;
157 }
158 paIov++;
159 }
160 return 0;
161}
162
163
164# undef iov_iter_count
165# define iov_iter_count(a_pIter) vbsf_iov_iter_count(a_pIter)
166static size_t vbsf_iov_iter_count(struct vbsf_iov_iter const *iter)
167{
168 size_t cbRet = 0;
169 size_t cLeft = iter->nr_segs;
170 struct iovec const *iov = iter->iov;
171 while (cLeft-- > 0) {
172 cbRet += iov->iov_len;
173 iov++;
174 }
175 return cbRet - iter->iov_offset;
176}
177
178
179# undef iov_iter_single_seg_count
180# define iov_iter_single_seg_count(a_pIter) vbsf_iov_iter_single_seg_count(a_pIter)
181static size_t vbsf_iov_iter_single_seg_count(struct vbsf_iov_iter const *iter)
182{
183 if (iter->nr_segs > 0)
184 return iter->iov->iov_len - iter->iov_offset;
185 return 0;
186}
187
188
189# undef iov_iter_advance
190# define iov_iter_advance(a_pIter, a_cbSkip) vbsf_iov_iter_advance(a_pIter, a_cbSkip)
191static void vbsf_iov_iter_advance(struct vbsf_iov_iter *iter, size_t cbSkip)
192{
193 SFLOG2(("vbsf_iov_iter_advance: cbSkip=%#zx\n", cbSkip));
194 if (iter->nr_segs > 0) {
195 size_t const cbLeftCur = iter->iov->iov_len - iter->iov_offset;
196 Assert(iter->iov_offset <= iter->iov->iov_len);
197 if (cbLeftCur > cbSkip) {
198 iter->iov_offset += cbSkip;
199 } else {
200 cbSkip -= cbLeftCur;
201 iter->iov_offset = 0;
202 iter->iov++;
203 iter->nr_segs--;
204 while (iter->nr_segs > 0) {
205 size_t const cbSeg = iter->iov->iov_len;
206 if (cbSeg > cbSkip) {
207 iter->iov_offset = cbSkip;
208 break;
209 }
210 cbSkip -= cbSeg;
211 iter->iov++;
212 iter->nr_segs--;
213 }
214 }
215 }
216}
217
218
219# undef iov_iter_get_pages
220# define iov_iter_get_pages(a_pIter, a_papPages, a_cbMax, a_cMaxPages, a_poffPg0) \
221 vbsf_iov_iter_get_pages(a_pIter, a_papPages, a_cbMax, a_cMaxPages, a_poffPg0)
222static ssize_t vbsf_iov_iter_get_pages(struct vbsf_iov_iter *iter, struct page **papPages,
223 size_t cbMax, unsigned cMaxPages, size_t *poffPg0)
224{
225 while (iter->nr_segs > 0) {
226 size_t const cbLeft = iter->iov->iov_len - iter->iov_offset;
227 Assert(iter->iov->iov_len >= iter->iov_offset);
228 if (cbLeft > 0) {
229 uintptr_t uPtrFrom = (uintptr_t)iter->iov->iov_base + iter->iov_offset;
230 size_t offPg0 = *poffPg0 = uPtrFrom & PAGE_OFFSET_MASK;
231 size_t cPagesLeft = RT_ALIGN_Z(offPg0 + cbLeft, PAGE_SIZE) >> PAGE_SHIFT;
232 size_t cPages = RT_MIN(cPagesLeft, cMaxPages);
233 struct task_struct *pTask = current;
234 size_t cPagesLocked;
235
236 down_read(&pTask->mm->mmap_sem);
237 cPagesLocked = get_user_pages(pTask, pTask->mm, uPtrFrom, cPages, iter->v_write, 1 /*force*/, papPages, NULL);
238 up_read(&pTask->mm->mmap_sem);
239 if (cPagesLocked == cPages) {
240 size_t cbRet = (cPages << PAGE_SHIFT) - offPg0;
241 if (cPages == cPagesLeft) {
242 size_t offLastPg = (uPtrFrom + cbLeft) & PAGE_OFFSET_MASK;
243 if (offLastPg)
244 cbRet -= PAGE_SIZE - offLastPg;
245 }
246 Assert(cbRet <= cbLeft);
247 return cbRet;
248 }
249 if (cPagesLocked > 0)
250 vbsf_unlock_user_pages(papPages, cPagesLocked, false /*fSetDirty*/, false /*fLockPgHack*/);
251 return -EFAULT;
252 }
253 iter->iov_offset = 0;
254 iter->iov++;
255 iter->nr_segs--;
256 }
257 AssertFailed();
258 return 0;
259}
260
261
262# undef iov_iter_truncate
263# define iov_iter_truncate(iter, cbNew) vbsf_iov_iter_truncate(iter, cbNew)
264static void vbsf_iov_iter_truncate(struct vbsf_iov_iter *iter, size_t cbNew)
265{
266 /* we have no counter or stuff, so it's a no-op. */
267 RT_NOREF(iter, cbNew);
268}
269
270
271# undef iov_iter_revert
272# define iov_iter_revert(a_pIter, a_cbRewind) vbsf_iov_iter_revert(a_pIter, a_cbRewind)
273void vbsf_iov_iter_revert(struct vbsf_iov_iter *iter, size_t cbRewind)
274{
275 SFLOG2(("vbsf_iov_iter_revert: cbRewind=%#zx\n", cbRewind));
276 if (iter->iov_offset > 0) {
277 if (cbRewind <= iter->iov_offset) {
278 iter->iov_offset -= cbRewind;
279 return;
280 }
281 cbRewind -= iter->iov_offset;
282 iter->iov_offset = 0;
283 }
284
285 while (cbRewind > 0) {
286 struct iovec const *pIov = --iter->iov;
287 size_t const cbSeg = pIov->iov_len;
288 iter->nr_segs++;
289
290 Assert((uintptr_t)pIov >= (uintptr_t)iter->iov_org);
291 Assert(iter->nr_segs <= iter->nr_segs_org);
292
293 if (cbRewind <= cbSeg) {
294 iter->iov_offset = cbSeg - cbRewind;
295 break;
296 }
297 cbRewind -= cbSeg;
298 }
299}
300
301#endif /* 2.6.19 <= linux < 3.16.0 */
302#if RTLNX_VER_RANGE(3,16,0, 3,16,35)
303
304/** This is for implementing cMaxPage on 3.16 which doesn't have it. */
305static ssize_t vbsf_iov_iter_get_pages_3_16(struct iov_iter *iter, struct page **papPages,
306 size_t cbMax, unsigned cMaxPages, size_t *poffPg0)
307{
308 if (!(iter->type & ITER_BVEC)) {
309 size_t const offPg0 = iter->iov_offset & PAGE_OFFSET_MASK;
310 size_t const cbMaxPages = ((size_t)cMaxPages << PAGE_SHIFT) - offPg0;
311 if (cbMax > cbMaxPages)
312 cbMax = cbMaxPages;
313 }
314 /* else: BVEC works a page at a time and shouldn't have much of a problem here. */
315 return iov_iter_get_pages(iter, papPages, cbMax, poffPg0);
316}
317# undef iov_iter_get_pages
318# define iov_iter_get_pages(a_pIter, a_papPages, a_cbMax, a_cMaxPages, a_poffPg0) \
319 vbsf_iov_iter_get_pages_3_16(a_pIter, a_papPages, a_cbMax, a_cMaxPages, a_poffPg0)
320
321#endif /* 3.16.0-3.16.34 */
322#if RTLNX_VER_RANGE(2,6,19, 3,18,0)
323
324static size_t copy_from_iter(uint8_t *pbDst, size_t cbToCopy, struct iov_iter *pSrcIter)
325{
326 size_t const cbTotal = cbToCopy;
327 Assert(iov_iter_count(pSrcIter) >= cbToCopy);
328# if RTLNX_VER_MIN(3,16,0)
329 if (pSrcIter->type & ITER_BVEC) {
330 while (cbToCopy > 0) {
331 size_t const offPage = (uintptr_t)pbDst & PAGE_OFFSET_MASK;
332 size_t const cbThisCopy = RT_MIN(PAGE_SIZE - offPage, cbToCopy);
333 struct page *pPage = rtR0MemObjLinuxVirtToPage(pbDst);
334 size_t cbCopied = copy_page_from_iter(pPage, offPage, cbThisCopy, pSrcIter);
335 AssertStmt(cbCopied <= cbThisCopy, cbCopied = cbThisCopy);
336 pbDst += cbCopied;
337 cbToCopy -= cbCopied;
338 if (cbCopied != cbToCopy)
339 break;
340 }
341 } else
342# endif
343 {
344 while (cbToCopy > 0) {
345 size_t cbThisCopy = iov_iter_single_seg_count(pSrcIter);
346 if (cbThisCopy > 0) {
347 if (cbThisCopy > cbToCopy)
348 cbThisCopy = cbToCopy;
349 if (pSrcIter->type & ITER_KVEC)
350 memcpy(pbDst, (void *)pSrcIter->iov->iov_base + pSrcIter->iov_offset, cbThisCopy);
351 else if (copy_from_user(pbDst, pSrcIter->iov->iov_base + pSrcIter->iov_offset, cbThisCopy) != 0)
352 break;
353 pbDst += cbThisCopy;
354 cbToCopy -= cbThisCopy;
355 }
356 iov_iter_advance(pSrcIter, cbThisCopy);
357 }
358 }
359 return cbTotal - cbToCopy;
360}
361
362
363static size_t copy_to_iter(uint8_t const *pbSrc, size_t cbToCopy, struct iov_iter *pDstIter)
364{
365 size_t const cbTotal = cbToCopy;
366 Assert(iov_iter_count(pDstIter) >= cbToCopy);
367# if RTLNX_VER_MIN(3,16,0)
368 if (pDstIter->type & ITER_BVEC) {
369 while (cbToCopy > 0) {
370 size_t const offPage = (uintptr_t)pbSrc & PAGE_OFFSET_MASK;
371 size_t const cbThisCopy = RT_MIN(PAGE_SIZE - offPage, cbToCopy);
372 struct page *pPage = rtR0MemObjLinuxVirtToPage((void *)pbSrc);
373 size_t cbCopied = copy_page_to_iter(pPage, offPage, cbThisCopy, pDstIter);
374 AssertStmt(cbCopied <= cbThisCopy, cbCopied = cbThisCopy);
375 pbSrc += cbCopied;
376 cbToCopy -= cbCopied;
377 if (cbCopied != cbToCopy)
378 break;
379 }
380 } else
381# endif
382 {
383 while (cbToCopy > 0) {
384 size_t cbThisCopy = iov_iter_single_seg_count(pDstIter);
385 if (cbThisCopy > 0) {
386 if (cbThisCopy > cbToCopy)
387 cbThisCopy = cbToCopy;
388 if (pDstIter->type & ITER_KVEC)
389 memcpy((void *)pDstIter->iov->iov_base + pDstIter->iov_offset, pbSrc, cbThisCopy);
390 else if (copy_to_user(pDstIter->iov->iov_base + pDstIter->iov_offset, pbSrc, cbThisCopy) != 0) {
391 break;
392 }
393 pbSrc += cbThisCopy;
394 cbToCopy -= cbThisCopy;
395 }
396 iov_iter_advance(pDstIter, cbThisCopy);
397 }
398 }
399 return cbTotal - cbToCopy;
400}
401
402#endif /* 3.16.0 <= linux < 3.18.0 */
403
404
405
406/*********************************************************************************************************************************
407* Handle management *
408*********************************************************************************************************************************/
409
410/**
411 * Called when an inode is released to unlink all handles that might impossibly
412 * still be associated with it.
413 *
414 * @param pInodeInfo The inode which handles to drop.
415 */
416void vbsf_handle_drop_chain(struct vbsf_inode_info *pInodeInfo)
417{
418 struct vbsf_handle *pCur, *pNext;
419 unsigned long fSavedFlags;
420 SFLOGFLOW(("vbsf_handle_drop_chain: %p\n", pInodeInfo));
421 spin_lock_irqsave(&g_SfHandleLock, fSavedFlags);
422
423 RTListForEachSafe(&pInodeInfo->HandleList, pCur, pNext, struct vbsf_handle, Entry) {
424 AssertMsg( (pCur->fFlags & (VBSF_HANDLE_F_MAGIC_MASK | VBSF_HANDLE_F_ON_LIST))
425 == (VBSF_HANDLE_F_MAGIC | VBSF_HANDLE_F_ON_LIST), ("%p %#x\n", pCur, pCur->fFlags));
426 pCur->fFlags |= VBSF_HANDLE_F_ON_LIST;
427 RTListNodeRemove(&pCur->Entry);
428 }
429
430 spin_unlock_irqrestore(&g_SfHandleLock, fSavedFlags);
431}
432
433
434/**
435 * Locates a handle that matches all the flags in @a fFlags.
436 *
437 * @returns Pointer to handle on success (retained), use vbsf_handle_release() to
438 * release it. NULL if no suitable handle was found.
439 * @param pInodeInfo The inode info to search.
440 * @param fFlagsSet The flags that must be set.
441 * @param fFlagsClear The flags that must be clear.
442 */
443struct vbsf_handle *vbsf_handle_find(struct vbsf_inode_info *pInodeInfo, uint32_t fFlagsSet, uint32_t fFlagsClear)
444{
445 struct vbsf_handle *pCur;
446 unsigned long fSavedFlags;
447 spin_lock_irqsave(&g_SfHandleLock, fSavedFlags);
448
449 RTListForEach(&pInodeInfo->HandleList, pCur, struct vbsf_handle, Entry) {
450 AssertMsg( (pCur->fFlags & (VBSF_HANDLE_F_MAGIC_MASK | VBSF_HANDLE_F_ON_LIST))
451 == (VBSF_HANDLE_F_MAGIC | VBSF_HANDLE_F_ON_LIST), ("%p %#x\n", pCur, pCur->fFlags));
452 if ((pCur->fFlags & (fFlagsSet | fFlagsClear)) == fFlagsSet) {
453 uint32_t cRefs = ASMAtomicIncU32(&pCur->cRefs);
454 if (cRefs > 1) {
455 spin_unlock_irqrestore(&g_SfHandleLock, fSavedFlags);
456 SFLOGFLOW(("vbsf_handle_find: returns %p\n", pCur));
457 return pCur;
458 }
459 /* Oops, already being closed (safe as it's only ever increased here). */
460 ASMAtomicDecU32(&pCur->cRefs);
461 }
462 }
463
464 spin_unlock_irqrestore(&g_SfHandleLock, fSavedFlags);
465 SFLOGFLOW(("vbsf_handle_find: returns NULL!\n"));
466 return NULL;
467}
468
469
470/**
471 * Slow worker for vbsf_handle_release() that does the freeing.
472 *
473 * @returns 0 (ref count).
474 * @param pHandle The handle to release.
475 * @param pSuperInfo The info structure for the shared folder associated with
476 * the handle.
477 * @param pszCaller The caller name (for logging failures).
478 */
479uint32_t vbsf_handle_release_slow(struct vbsf_handle *pHandle, struct vbsf_super_info *pSuperInfo, const char *pszCaller)
480{
481 int rc;
482 unsigned long fSavedFlags;
483
484 SFLOGFLOW(("vbsf_handle_release_slow: %p (%s)\n", pHandle, pszCaller));
485
486 /*
487 * Remove from the list.
488 */
489 spin_lock_irqsave(&g_SfHandleLock, fSavedFlags);
490
491 AssertMsg((pHandle->fFlags & VBSF_HANDLE_F_MAGIC_MASK) == VBSF_HANDLE_F_MAGIC, ("%p %#x\n", pHandle, pHandle->fFlags));
492 Assert(pHandle->pInodeInfo);
493 Assert(pHandle->pInodeInfo && pHandle->pInodeInfo->u32Magic == SF_INODE_INFO_MAGIC);
494
495 if (pHandle->fFlags & VBSF_HANDLE_F_ON_LIST) {
496 pHandle->fFlags &= ~VBSF_HANDLE_F_ON_LIST;
497 RTListNodeRemove(&pHandle->Entry);
498 }
499
500 spin_unlock_irqrestore(&g_SfHandleLock, fSavedFlags);
501
502 /*
503 * Actually destroy it.
504 */
505 rc = VbglR0SfHostReqCloseSimple(pSuperInfo->map.root, pHandle->hHost);
506 if (RT_FAILURE(rc))
507 LogFunc(("Caller %s: VbglR0SfHostReqCloseSimple %#RX64 failed with rc=%Rrc\n", pszCaller, pHandle->hHost, rc));
508 pHandle->hHost = SHFL_HANDLE_NIL;
509 pHandle->fFlags = VBSF_HANDLE_F_MAGIC_DEAD;
510 kfree(pHandle);
511 return 0;
512}
513
514
515/**
516 * Appends a handle to a handle list.
517 *
518 * @param pInodeInfo The inode to add it to.
519 * @param pHandle The handle to add.
520 */
521void vbsf_handle_append(struct vbsf_inode_info *pInodeInfo, struct vbsf_handle *pHandle)
522{
523#ifdef VBOX_STRICT
524 struct vbsf_handle *pCur;
525#endif
526 unsigned long fSavedFlags;
527
528 SFLOGFLOW(("vbsf_handle_append: %p (to %p)\n", pHandle, pInodeInfo));
529 AssertMsg((pHandle->fFlags & (VBSF_HANDLE_F_MAGIC_MASK | VBSF_HANDLE_F_ON_LIST)) == VBSF_HANDLE_F_MAGIC,
530 ("%p %#x\n", pHandle, pHandle->fFlags));
531 Assert(pInodeInfo->u32Magic == SF_INODE_INFO_MAGIC);
532
533 spin_lock_irqsave(&g_SfHandleLock, fSavedFlags);
534
535 AssertMsg((pHandle->fFlags & (VBSF_HANDLE_F_MAGIC_MASK | VBSF_HANDLE_F_ON_LIST)) == VBSF_HANDLE_F_MAGIC,
536 ("%p %#x\n", pHandle, pHandle->fFlags));
537#ifdef VBOX_STRICT
538 RTListForEach(&pInodeInfo->HandleList, pCur, struct vbsf_handle, Entry) {
539 Assert(pCur != pHandle);
540 AssertMsg( (pCur->fFlags & (VBSF_HANDLE_F_MAGIC_MASK | VBSF_HANDLE_F_ON_LIST))
541 == (VBSF_HANDLE_F_MAGIC | VBSF_HANDLE_F_ON_LIST), ("%p %#x\n", pCur, pCur->fFlags));
542 }
543 pHandle->pInodeInfo = pInodeInfo;
544#endif
545
546 pHandle->fFlags |= VBSF_HANDLE_F_ON_LIST;
547 RTListAppend(&pInodeInfo->HandleList, &pHandle->Entry);
548
549 spin_unlock_irqrestore(&g_SfHandleLock, fSavedFlags);
550}
551
552
553
554/*********************************************************************************************************************************
555* Misc *
556*********************************************************************************************************************************/
557
558#if RTLNX_VER_MAX(2,6,6)
559/** Any writable mappings? */
560DECLINLINE(bool) mapping_writably_mapped(struct address_space const *mapping)
561{
562# if RTLNX_VER_MIN(2,5,6)
563 return !list_empty(&mapping->i_mmap_shared);
564# else
565 return mapping->i_mmap_shared != NULL;
566# endif
567}
568#endif
569
570
571#if RTLNX_VER_MAX(2,5,12)
572/** Missing in 2.4.x, so just stub it for now. */
573DECLINLINE(bool) PageWriteback(struct page const *page)
574{
575 return false;
576}
577#endif
578
579
580/**
581 * Helper for deciding wheter we should do a read via the page cache or not.
582 *
583 * By default we will only use the page cache if there is a writable memory
584 * mapping of the file with a chance that it may have modified any of the pages
585 * already.
586 */
587DECLINLINE(bool) vbsf_should_use_cached_read(struct file *file, struct address_space *mapping, struct vbsf_super_info *pSuperInfo)
588{
589 if ( (file->f_flags & O_DIRECT)
590 || pSuperInfo->enmCacheMode == kVbsfCacheMode_None)
591 return false;
592 if ( pSuperInfo->enmCacheMode == kVbsfCacheMode_Read
593 || pSuperInfo->enmCacheMode == kVbsfCacheMode_ReadWrite)
594 return true;
595 Assert(pSuperInfo->enmCacheMode == kVbsfCacheMode_Strict);
596 return mapping
597 && mapping->nrpages > 0
598 && mapping_writably_mapped(mapping);
599}
600
601
602
603/*********************************************************************************************************************************
604* Pipe / splice stuff mainly for 2.6.17 >= linux < 2.6.31 (where no fallbacks were available) *
605*********************************************************************************************************************************/
606
607#if RTLNX_VER_RANGE(2,6,17, 3,16,0)
608
609# if RTLNX_VER_MAX(2,6,30)
610# define LOCK_PIPE(a_pPipe) do { if ((a_pPipe)->inode) mutex_lock(&(a_pPipe)->inode->i_mutex); } while (0)
611# define UNLOCK_PIPE(a_pPipe) do { if ((a_pPipe)->inode) mutex_unlock(&(a_pPipe)->inode->i_mutex); } while (0)
612# else
613# define LOCK_PIPE(a_pPipe) pipe_lock(a_pPipe)
614# define UNLOCK_PIPE(a_pPipe) pipe_unlock(a_pPipe)
615# endif
616
617
618/** Waits for the pipe buffer status to change. */
619static void vbsf_wait_pipe(struct pipe_inode_info *pPipe)
620{
621 DEFINE_WAIT(WaitStuff);
622# ifdef TASK_NONINTERACTIVE
623 prepare_to_wait(&pPipe->wait, &WaitStuff, TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE);
624# else
625 prepare_to_wait(&pPipe->wait, &WaitStuff, TASK_INTERRUPTIBLE);
626# endif
627 UNLOCK_PIPE(pPipe);
628
629 schedule();
630
631 finish_wait(&pPipe->wait, &WaitStuff);
632 LOCK_PIPE(pPipe);
633}
634
635
636/** Worker for vbsf_feed_pages_to_pipe that wakes up readers. */
637static void vbsf_wake_up_pipe(struct pipe_inode_info *pPipe, bool fReaders)
638{
639 smp_mb();
640 if (waitqueue_active(&pPipe->wait))
641 wake_up_interruptible_sync(&pPipe->wait);
642 if (fReaders)
643 kill_fasync(&pPipe->fasync_readers, SIGIO, POLL_IN);
644 else
645 kill_fasync(&pPipe->fasync_writers, SIGIO, POLL_OUT);
646}
647
648#endif
649#if RTLNX_VER_RANGE(2,6,17, 2,6,31)
650
651/** Verify pipe buffer content (needed for page-cache to ensure idle page). */
652static int vbsf_pipe_buf_confirm(struct pipe_inode_info *pPipe, struct pipe_buffer *pPipeBuf)
653{
654 /*SFLOG3(("vbsf_pipe_buf_confirm: %p\n", pPipeBuf));*/
655 return 0;
656}
657
658
659/** Maps the buffer page. */
660static void *vbsf_pipe_buf_map(struct pipe_inode_info *pPipe, struct pipe_buffer *pPipeBuf, int atomic)
661{
662 void *pvRet;
663 if (!atomic)
664 pvRet = kmap(pPipeBuf->page);
665 else {
666 pPipeBuf->flags |= PIPE_BUF_FLAG_ATOMIC;
667 pvRet = kmap_atomic(pPipeBuf->page, KM_USER0);
668 }
669 /*SFLOG3(("vbsf_pipe_buf_map: %p -> %p\n", pPipeBuf, pvRet));*/
670 return pvRet;
671}
672
673
674/** Unmaps the buffer page. */
675static void vbsf_pipe_buf_unmap(struct pipe_inode_info *pPipe, struct pipe_buffer *pPipeBuf, void *pvMapping)
676{
677 /*SFLOG3(("vbsf_pipe_buf_unmap: %p/%p\n", pPipeBuf, pvMapping)); */
678 if (!(pPipeBuf->flags & PIPE_BUF_FLAG_ATOMIC))
679 kunmap(pPipeBuf->page);
680 else {
681 pPipeBuf->flags &= ~PIPE_BUF_FLAG_ATOMIC;
682 kunmap_atomic(pvMapping, KM_USER0);
683 }
684}
685
686
687/** Gets a reference to the page. */
688static void vbsf_pipe_buf_get(struct pipe_inode_info *pPipe, struct pipe_buffer *pPipeBuf)
689{
690 page_cache_get(pPipeBuf->page);
691 /*SFLOG3(("vbsf_pipe_buf_get: %p (return count=%d)\n", pPipeBuf, page_count(pPipeBuf->page)));*/
692}
693
694
695/** Release the buffer page (counter to vbsf_pipe_buf_get). */
696static void vbsf_pipe_buf_release(struct pipe_inode_info *pPipe, struct pipe_buffer *pPipeBuf)
697{
698 /*SFLOG3(("vbsf_pipe_buf_release: %p (incoming count=%d)\n", pPipeBuf, page_count(pPipeBuf->page)));*/
699 page_cache_release(pPipeBuf->page);
700}
701
702
703/** Attempt to steal the page.
704 * @returns 0 success, 1 on failure. */
705static int vbsf_pipe_buf_steal(struct pipe_inode_info *pPipe, struct pipe_buffer *pPipeBuf)
706{
707 if (page_count(pPipeBuf->page) == 1) {
708 lock_page(pPipeBuf->page);
709 SFLOG3(("vbsf_pipe_buf_steal: %p -> 0\n", pPipeBuf));
710 return 0;
711 }
712 SFLOG3(("vbsf_pipe_buf_steal: %p -> 1\n", pPipeBuf));
713 return 1;
714}
715
716
717/**
718 * Pipe buffer operations for used by vbsf_feed_pages_to_pipe.
719 */
720static struct pipe_buf_operations vbsf_pipe_buf_ops = {
721 .can_merge = 0,
722# if RTLNX_VER_MIN(2,6,23)
723 .confirm = vbsf_pipe_buf_confirm,
724# else
725 .pin = vbsf_pipe_buf_confirm,
726# endif
727 .map = vbsf_pipe_buf_map,
728 .unmap = vbsf_pipe_buf_unmap,
729 .get = vbsf_pipe_buf_get,
730 .release = vbsf_pipe_buf_release,
731 .steal = vbsf_pipe_buf_steal,
732};
733
734
735/**
736 * Feeds the pages to the pipe.
737 *
738 * Pages given to the pipe are set to NULL in papPages.
739 */
740static ssize_t vbsf_feed_pages_to_pipe(struct pipe_inode_info *pPipe, struct page **papPages, size_t cPages, uint32_t offPg0,
741 uint32_t cbActual, unsigned fFlags)
742{
743 ssize_t cbRet = 0;
744 size_t iPage = 0;
745 bool fNeedWakeUp = false;
746
747 LOCK_PIPE(pPipe);
748 for (;;) {
749 if ( pPipe->readers > 0
750 && pPipe->nrbufs < PIPE_BUFFERS) {
751 struct pipe_buffer *pPipeBuf = &pPipe->bufs[(pPipe->curbuf + pPipe->nrbufs) % PIPE_BUFFERS];
752 uint32_t const cbThisPage = RT_MIN(cbActual, PAGE_SIZE - offPg0);
753 pPipeBuf->len = cbThisPage;
754 pPipeBuf->offset = offPg0;
755# if RTLNX_VER_MIN(2,6,23)
756 pPipeBuf->private = 0;
757# endif
758 pPipeBuf->ops = &vbsf_pipe_buf_ops;
759 pPipeBuf->flags = fFlags & SPLICE_F_GIFT ? PIPE_BUF_FLAG_GIFT : 0;
760 pPipeBuf->page = papPages[iPage];
761
762 papPages[iPage++] = NULL;
763 pPipe->nrbufs++;
764 fNeedWakeUp |= pPipe->inode != NULL;
765 offPg0 = 0;
766 cbRet += cbThisPage;
767
768 /* done? */
769 cbActual -= cbThisPage;
770 if (!cbActual)
771 break;
772 } else if (pPipe->readers == 0) {
773 SFLOGFLOW(("vbsf_feed_pages_to_pipe: no readers!\n"));
774 send_sig(SIGPIPE, current, 0);
775 if (cbRet == 0)
776 cbRet = -EPIPE;
777 break;
778 } else if (fFlags & SPLICE_F_NONBLOCK) {
779 if (cbRet == 0)
780 cbRet = -EAGAIN;
781 break;
782 } else if (signal_pending(current)) {
783 if (cbRet == 0)
784 cbRet = -ERESTARTSYS;
785 SFLOGFLOW(("vbsf_feed_pages_to_pipe: pending signal! (%zd)\n", cbRet));
786 break;
787 } else {
788 if (fNeedWakeUp) {
789 vbsf_wake_up_pipe(pPipe, true /*fReaders*/);
790 fNeedWakeUp = 0;
791 }
792 pPipe->waiting_writers++;
793 vbsf_wait_pipe(pPipe);
794 pPipe->waiting_writers--;
795 }
796 }
797 UNLOCK_PIPE(pPipe);
798
799 if (fNeedWakeUp)
800 vbsf_wake_up_pipe(pPipe, true /*fReaders*/);
801
802 return cbRet;
803}
804
805
806/**
807 * For splicing from a file to a pipe.
808 */
809static ssize_t vbsf_splice_read(struct file *file, loff_t *poffset, struct pipe_inode_info *pipe, size_t len, unsigned int flags)
810{
811 struct inode *inode = VBSF_GET_F_DENTRY(file)->d_inode;
812 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
813 ssize_t cbRet;
814
815 SFLOGFLOW(("vbsf_splice_read: file=%p poffset=%p{%#RX64} pipe=%p len=%#zx flags=%#x\n", file, poffset, *poffset, pipe, len, flags));
816 if (vbsf_should_use_cached_read(file, inode->i_mapping, pSuperInfo)) {
817 cbRet = generic_file_splice_read(file, poffset, pipe, len, flags);
818 } else {
819 /*
820 * Create a read request.
821 */
822 loff_t offFile = *poffset;
823 size_t cPages = RT_MIN(RT_ALIGN_Z((offFile & ~PAGE_CACHE_MASK) + len, PAGE_CACHE_SIZE) >> PAGE_CACHE_SHIFT,
824 PIPE_BUFFERS);
825 VBOXSFREADPGLSTREQ *pReq = (VBOXSFREADPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFREADPGLSTREQ,
826 PgLst.aPages[cPages]));
827 if (pReq) {
828 /*
829 * Allocate pages.
830 */
831 struct page *apPages[PIPE_BUFFERS];
832 size_t i;
833 pReq->PgLst.offFirstPage = (uint16_t)offFile & (uint16_t)PAGE_OFFSET_MASK;
834 cbRet = 0;
835 for (i = 0; i < cPages; i++) {
836 struct page *pPage;
837 apPages[i] = pPage = alloc_page(GFP_USER);
838 if (pPage) {
839 pReq->PgLst.aPages[i] = page_to_phys(pPage);
840# ifdef VBOX_STRICT
841 ASMMemFill32(kmap(pPage), PAGE_SIZE, UINT32_C(0xdeadbeef));
842 kunmap(pPage);
843# endif
844 } else {
845 cbRet = -ENOMEM;
846 break;
847 }
848 }
849 if (cbRet == 0) {
850 /*
851 * Do the reading.
852 */
853 uint32_t const cbToRead = RT_MIN((cPages << PAGE_SHIFT) - (offFile & PAGE_OFFSET_MASK), len);
854 struct vbsf_reg_info *sf_r = (struct vbsf_reg_info *)file->private_data;
855 int vrc = VbglR0SfHostReqReadPgLst(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, offFile, cbToRead, cPages);
856 if (RT_SUCCESS(vrc)) {
857 /*
858 * Get the number of bytes read, jettison the request
859 * and, in case of EOF, any unnecessary pages.
860 */
861 uint32_t cbActual = pReq->Parms.cb32Read.u.value32;
862 AssertStmt(cbActual <= cbToRead, cbActual = cbToRead);
863 SFLOG2(("vbsf_splice_read: read -> %#x bytes @ %#RX64\n", cbActual, offFile));
864
865 VbglR0PhysHeapFree(pReq);
866 pReq = NULL;
867
868 /*
869 * Now, feed it to the pipe thingy.
870 * This will take ownership of the all pages no matter what happens.
871 */
872 cbRet = vbsf_feed_pages_to_pipe(pipe, apPages, cPages, offFile & PAGE_OFFSET_MASK, cbActual, flags);
873 if (cbRet > 0)
874 *poffset = offFile + cbRet;
875 } else {
876 cbRet = -RTErrConvertToErrno(vrc);
877 SFLOGFLOW(("vbsf_splice_read: Read failed: %Rrc -> %zd\n", vrc, cbRet));
878 }
879 i = cPages;
880 }
881
882 while (i-- > 0)
883 if (apPages[i])
884 __free_pages(apPages[i], 0);
885 if (pReq)
886 VbglR0PhysHeapFree(pReq);
887 } else {
888 cbRet = -ENOMEM;
889 }
890 }
891 SFLOGFLOW(("vbsf_splice_read: returns %zd (%#zx), *poffset=%#RX64\n", cbRet, cbRet, *poffset));
892 return cbRet;
893}
894
895#endif /* 2.6.17 <= LINUX_VERSION_CODE < 2.6.31 */
896#if RTLNX_VER_RANGE(2,6,17, 3,16,0)
897
898/**
899 * For splicing from a pipe to a file.
900 *
901 * Since we can combine buffers and request allocations, this should be faster
902 * than the default implementation.
903 */
904static ssize_t vbsf_splice_write(struct pipe_inode_info *pPipe, struct file *file, loff_t *poffset, size_t len, unsigned int flags)
905{
906 struct inode *inode = VBSF_GET_F_DENTRY(file)->d_inode;
907 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
908 ssize_t cbRet;
909
910 SFLOGFLOW(("vbsf_splice_write: pPipe=%p file=%p poffset=%p{%#RX64} len=%#zx flags=%#x\n", pPipe, file, poffset, *poffset, len, flags));
911 /** @todo later if (false) {
912 cbRet = generic_file_splice_write(pPipe, file, poffset, len, flags);
913 } else */ {
914 /*
915 * Prepare a write request.
916 */
917# ifdef PIPE_BUFFERS
918 uint32_t const cMaxPages = RT_MIN(PIPE_BUFFERS, RT_ALIGN_Z(len, PAGE_SIZE) >> PAGE_SHIFT);
919# else
920 uint32_t const cMaxPages = RT_MIN(RT_MAX(RT_MIN(pPipe->buffers, 256), PIPE_DEF_BUFFERS),
921 RT_ALIGN_Z(len, PAGE_SIZE) >> PAGE_SHIFT);
922# endif
923 VBOXSFWRITEPGLSTREQ *pReq = (VBOXSFWRITEPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFREADPGLSTREQ,
924 PgLst.aPages[cMaxPages]));
925 if (pReq) {
926 /*
927 * Feed from the pipe.
928 */
929 struct vbsf_reg_info *sf_r = (struct vbsf_reg_info *)file->private_data;
930 struct address_space *mapping = inode->i_mapping;
931 loff_t offFile = *poffset;
932 bool fNeedWakeUp = false;
933 cbRet = 0;
934
935 LOCK_PIPE(pPipe);
936
937 for (;;) {
938 unsigned cBufs = pPipe->nrbufs;
939 /*SFLOG2(("vbsf_splice_write: nrbufs=%#x curbuf=%#x\n", cBufs, pPipe->curbuf));*/
940 if (cBufs) {
941 /*
942 * There is data available. Write it to the file.
943 */
944 int vrc;
945 struct pipe_buffer *pPipeBuf = &pPipe->bufs[pPipe->curbuf];
946 uint32_t cPagesToWrite = 1;
947 uint32_t cbToWrite = pPipeBuf->len;
948
949 Assert(pPipeBuf->offset < PAGE_SIZE);
950 Assert(pPipeBuf->offset + pPipeBuf->len <= PAGE_SIZE);
951
952 pReq->PgLst.offFirstPage = pPipeBuf->offset & PAGE_OFFSET;
953 pReq->PgLst.aPages[0] = page_to_phys(pPipeBuf->page);
954
955 /* Add any adjacent page buffers: */
956 while ( cPagesToWrite < cBufs
957 && cPagesToWrite < cMaxPages
958 && ((pReq->PgLst.offFirstPage + cbToWrite) & PAGE_OFFSET_MASK) == 0) {
959# ifdef PIPE_BUFFERS
960 struct pipe_buffer *pPipeBuf2 = &pPipe->bufs[(pPipe->curbuf + cPagesToWrite) % PIPE_BUFFERS];
961# else
962 struct pipe_buffer *pPipeBuf2 = &pPipe->bufs[(pPipe->curbuf + cPagesToWrite) % pPipe->buffers];
963# endif
964 Assert(pPipeBuf2->len <= PAGE_SIZE);
965 Assert(pPipeBuf2->offset < PAGE_SIZE);
966 if (pPipeBuf2->offset != 0)
967 break;
968 pReq->PgLst.aPages[cPagesToWrite] = page_to_phys(pPipeBuf2->page);
969 cbToWrite += pPipeBuf2->len;
970 cPagesToWrite += 1;
971 }
972
973 /* Check that we don't have signals pending before we issue the write, as
974 we'll only end up having to cancel the HGCM request 99% of the time: */
975 if (!signal_pending(current)) {
976 struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(inode);
977 vrc = VbglR0SfHostReqWritePgLst(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, offFile,
978 cbToWrite, cPagesToWrite);
979 sf_i->ModificationTimeAtOurLastWrite = sf_i->ModificationTime;
980 } else
981 vrc = VERR_INTERRUPTED;
982 if (RT_SUCCESS(vrc)) {
983 /*
984 * Get the number of bytes actually written, update file position
985 * and return value, and advance the pipe buffer.
986 */
987 uint32_t cbActual = pReq->Parms.cb32Write.u.value32;
988 AssertStmt(cbActual <= cbToWrite, cbActual = cbToWrite);
989 SFLOG2(("vbsf_splice_write: write -> %#x bytes @ %#RX64\n", cbActual, offFile));
990
991 cbRet += cbActual;
992
993 while (cbActual > 0) {
994 uint32_t cbAdvance = RT_MIN(pPipeBuf->len, cbActual);
995
996 vbsf_reg_write_sync_page_cache(mapping, offFile, cbAdvance, NULL,
997 &pPipeBuf->page, pPipeBuf->offset, 1);
998
999 offFile += cbAdvance;
1000 cbActual -= cbAdvance;
1001 pPipeBuf->offset += cbAdvance;
1002 pPipeBuf->len -= cbAdvance;
1003
1004 if (!pPipeBuf->len) {
1005 struct pipe_buf_operations const *pOps = pPipeBuf->ops;
1006 pPipeBuf->ops = NULL;
1007 pOps->release(pPipe, pPipeBuf);
1008
1009# ifdef PIPE_BUFFERS
1010 pPipe->curbuf = (pPipe->curbuf + 1) % PIPE_BUFFERS;
1011# else
1012 pPipe->curbuf = (pPipe->curbuf + 1) % pPipe->buffers;
1013# endif
1014 pPipe->nrbufs -= 1;
1015 pPipeBuf = &pPipe->bufs[pPipe->curbuf];
1016
1017# if RTLNX_VER_MAX(2,6,30)
1018 fNeedWakeUp |= pPipe->inode != NULL;
1019# else
1020 fNeedWakeUp = true;
1021# endif
1022 } else {
1023 Assert(cbActual == 0);
1024 break;
1025 }
1026 }
1027
1028 *poffset = offFile;
1029 } else {
1030 if (cbRet == 0)
1031 cbRet = vrc == VERR_INTERRUPTED ? -ERESTARTSYS : -RTErrConvertToErrno(vrc);
1032 SFLOGFLOW(("vbsf_splice_write: Write failed: %Rrc -> %zd (cbRet=%#zx)\n",
1033 vrc, -RTErrConvertToErrno(vrc), cbRet));
1034 break;
1035 }
1036 } else {
1037 /*
1038 * Wait for data to become available, if there is chance that'll happen.
1039 */
1040 /* Quit if there are no writers (think EOF): */
1041 if (pPipe->writers == 0) {
1042 SFLOGFLOW(("vbsf_splice_write: No buffers. No writers. The show is done!\n"));
1043 break;
1044 }
1045
1046 /* Quit if if we've written some and no writers waiting on the lock: */
1047 if (cbRet > 0 && pPipe->waiting_writers == 0) {
1048 SFLOGFLOW(("vbsf_splice_write: No waiting writers, returning what we've got.\n"));
1049 break;
1050 }
1051
1052 /* Quit with EAGAIN if non-blocking: */
1053 if (flags & SPLICE_F_NONBLOCK) {
1054 if (cbRet == 0)
1055 cbRet = -EAGAIN;
1056 break;
1057 }
1058
1059 /* Quit if we've got pending signals: */
1060 if (signal_pending(current)) {
1061 if (cbRet == 0)
1062 cbRet = -ERESTARTSYS;
1063 SFLOGFLOW(("vbsf_splice_write: pending signal! (%zd)\n", cbRet));
1064 break;
1065 }
1066
1067 /* Wake up writers before we start waiting: */
1068 if (fNeedWakeUp) {
1069 vbsf_wake_up_pipe(pPipe, false /*fReaders*/);
1070 fNeedWakeUp = false;
1071 }
1072 vbsf_wait_pipe(pPipe);
1073 }
1074 } /* feed loop */
1075
1076 if (fNeedWakeUp)
1077 vbsf_wake_up_pipe(pPipe, false /*fReaders*/);
1078
1079 UNLOCK_PIPE(pPipe);
1080
1081 VbglR0PhysHeapFree(pReq);
1082 } else {
1083 cbRet = -ENOMEM;
1084 }
1085 }
1086 SFLOGFLOW(("vbsf_splice_write: returns %zd (%#zx), *poffset=%#RX64\n", cbRet, cbRet, *poffset));
1087 return cbRet;
1088}
1089
1090#endif /* 2.6.17 <= LINUX_VERSION_CODE < 3.16.0 */
1091
1092#if RTLNX_VER_RANGE(2,5,30, 2,6,23)
1093/**
1094 * Our own senfile implementation that does not go via the page cache like
1095 * generic_file_sendfile() does.
1096 */
1097static ssize_t vbsf_reg_sendfile(struct file *pFile, loff_t *poffFile, size_t cbToSend, read_actor_t pfnActor,
1098# if RTLNX_VER_MIN(2,6,8)
1099 void *pvUser
1100# else
1101 void __user *pvUser
1102# endif
1103 )
1104{
1105 struct inode *inode = VBSF_GET_F_DENTRY(pFile)->d_inode;
1106 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
1107 ssize_t cbRet;
1108 SFLOGFLOW(("vbsf_reg_sendfile: pFile=%p poffFile=%p{%#RX64} cbToSend=%#zx pfnActor=%p pvUser=%p\n",
1109 pFile, poffFile, poffFile ? *poffFile : 0, cbToSend, pfnActor, pvUser));
1110 Assert(pSuperInfo);
1111
1112 /*
1113 * Return immediately if asked to send nothing.
1114 */
1115 if (cbToSend == 0)
1116 return 0;
1117
1118 /*
1119 * Like for vbsf_reg_read() and vbsf_reg_read_iter(), we allow going via
1120 * the page cache in some cases or configs.
1121 */
1122 if (vbsf_should_use_cached_read(pFile, inode->i_mapping, pSuperInfo)) {
1123 cbRet = generic_file_sendfile(pFile, poffFile, cbToSend, pfnActor, pvUser);
1124 SFLOGFLOW(("vbsf_reg_sendfile: returns %#zx *poffFile=%#RX64 [generic_file_sendfile]\n", cbRet, poffFile ? *poffFile : UINT64_MAX));
1125 } else {
1126 /*
1127 * Allocate a request and a bunch of pages for reading from the file.
1128 */
1129 struct page *apPages[16];
1130 loff_t offFile = poffFile ? *poffFile : 0;
1131 size_t const cPages = cbToSend + ((size_t)offFile & PAGE_OFFSET_MASK) >= RT_ELEMENTS(apPages) * PAGE_SIZE
1132 ? RT_ELEMENTS(apPages)
1133 : RT_ALIGN_Z(cbToSend + ((size_t)offFile & PAGE_OFFSET_MASK), PAGE_SIZE) >> PAGE_SHIFT;
1134 size_t iPage;
1135 VBOXSFREADPGLSTREQ *pReq = (VBOXSFREADPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFREADPGLSTREQ,
1136 PgLst.aPages[cPages]));
1137 if (pReq) {
1138 Assert(cPages > 0);
1139 cbRet = 0;
1140 for (iPage = 0; iPage < cPages; iPage++) {
1141 struct page *pPage;
1142 apPages[iPage] = pPage = alloc_page(GFP_USER);
1143 if (pPage) {
1144 Assert(page_count(pPage) == 1);
1145 pReq->PgLst.aPages[iPage] = page_to_phys(pPage);
1146 } else {
1147 while (iPage-- > 0)
1148 vbsf_put_page(apPages[iPage]);
1149 cbRet = -ENOMEM;
1150 break;
1151 }
1152 }
1153 if (cbRet == 0) {
1154 /*
1155 * Do the job.
1156 */
1157 struct vbsf_reg_info *sf_r = (struct vbsf_reg_info *)pFile->private_data;
1158 read_descriptor_t RdDesc;
1159 RdDesc.count = cbToSend;
1160# if RTLNX_VER_MIN(2,6,8)
1161 RdDesc.arg.data = pvUser;
1162# else
1163 RdDesc.buf = pvUser;
1164# endif
1165 RdDesc.written = 0;
1166 RdDesc.error = 0;
1167
1168 Assert(sf_r);
1169 Assert((sf_r->Handle.fFlags & VBSF_HANDLE_F_MAGIC_MASK) == VBSF_HANDLE_F_MAGIC);
1170
1171 while (cbToSend > 0) {
1172 /*
1173 * Read another chunk. For paranoid reasons, we keep data where the page cache
1174 * would keep it, i.e. page offset bits corresponds to the file offset bits.
1175 */
1176 uint32_t const offPg0 = (uint32_t)offFile & (uint32_t)PAGE_OFFSET_MASK;
1177 uint32_t const cbToRead = RT_MIN((cPages << PAGE_SHIFT) - offPg0, cbToSend);
1178 uint32_t const cPagesToRead = RT_ALIGN_Z(cbToRead + offPg0, PAGE_SIZE) >> PAGE_SHIFT;
1179 int vrc;
1180 pReq->PgLst.offFirstPage = (uint16_t)offPg0;
1181 if (!signal_pending(current))
1182 vrc = VbglR0SfHostReqReadPgLst(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, offFile,
1183 cbToRead, cPagesToRead);
1184 else
1185 vrc = VERR_INTERRUPTED;
1186 if (RT_SUCCESS(vrc)) {
1187 /*
1188 * Pass what we read to the actor.
1189 */
1190 uint32_t off = offPg0;
1191 uint32_t cbActual = pReq->Parms.cb32Read.u.value32;
1192 bool const fIsEof = cbActual < cbToRead;
1193 AssertStmt(cbActual <= cbToRead, cbActual = cbToRead);
1194 SFLOG3(("vbsf_reg_sendfile: Read %#x bytes (offPg0=%#x), wanted %#x ...\n", cbActual, offPg0, cbToRead));
1195
1196 iPage = 0;
1197 while (cbActual > 0) {
1198 uint32_t const cbPage = RT_MIN(cbActual, PAGE_SIZE - off);
1199 int const cbRetActor = pfnActor(&RdDesc, apPages[iPage], off, cbPage);
1200 Assert(cbRetActor >= 0); /* Returns zero on failure, with RdDesc.error holding the status code. */
1201
1202 AssertMsg(iPage < cPages && iPage < cPagesToRead, ("iPage=%#x cPages=%#x cPagesToRead=%#x\n", iPage, cPages, cPagesToRead));
1203
1204 offFile += cbRetActor;
1205 if ((uint32_t)cbRetActor == cbPage && RdDesc.count > 0) {
1206 cbActual -= cbPage;
1207 cbToSend -= cbPage;
1208 iPage++;
1209 } else {
1210 SFLOG3(("vbsf_reg_sendfile: cbRetActor=%#x (%d) cbPage=%#x RdDesc{count=%#lx error=%d} iPage=%#x/%#x/%#x cbToSend=%#zx\n",
1211 cbRetActor, cbRetActor, cbPage, RdDesc.count, RdDesc.error, iPage, cPagesToRead, cPages, cbToSend));
1212 vrc = VERR_CALLBACK_RETURN;
1213 break;
1214 }
1215 off = 0;
1216 }
1217
1218 /*
1219 * Are we done yet?
1220 */
1221 if (RT_FAILURE_NP(vrc) || cbToSend == 0 || RdDesc.error != 0 || fIsEof) {
1222 break;
1223 }
1224
1225 /*
1226 * Replace pages held by the actor.
1227 */
1228 vrc = VINF_SUCCESS;
1229 for (iPage = 0; iPage < cPages; iPage++) {
1230 struct page *pPage = apPages[iPage];
1231 if (page_count(pPage) != 1) {
1232 struct page *pNewPage = alloc_page(GFP_USER);
1233 if (pNewPage) {
1234 SFLOGFLOW(("vbsf_reg_sendfile: Replacing page #%x: %p -> %p\n", iPage, pPage, pNewPage));
1235 vbsf_put_page(pPage);
1236 apPages[iPage] = pNewPage;
1237 } else {
1238 SFLOGFLOW(("vbsf_reg_sendfile: Failed to allocate a replacement page.\n"));
1239 vrc = VERR_NO_MEMORY;
1240 break;
1241 }
1242 }
1243 }
1244 if (RT_FAILURE(vrc))
1245 break; /* RdDesc.written should be non-zero, so don't bother with setting error. */
1246 } else {
1247 RdDesc.error = vrc == VERR_INTERRUPTED ? -ERESTARTSYS : -RTErrConvertToErrno(vrc);
1248 SFLOGFLOW(("vbsf_reg_sendfile: Read failed: %Rrc -> %zd (RdDesc.error=%#d)\n",
1249 vrc, -RTErrConvertToErrno(vrc), RdDesc.error));
1250 break;
1251 }
1252 }
1253
1254 /*
1255 * Free memory.
1256 */
1257 for (iPage = 0; iPage < cPages; iPage++)
1258 vbsf_put_page(apPages[iPage]);
1259
1260 /*
1261 * Set the return values.
1262 */
1263 if (RdDesc.written) {
1264 cbRet = RdDesc.written;
1265 if (poffFile)
1266 *poffFile = offFile;
1267 } else {
1268 cbRet = RdDesc.error;
1269 }
1270 }
1271 VbglR0PhysHeapFree(pReq);
1272 } else {
1273 cbRet = -ENOMEM;
1274 }
1275 SFLOGFLOW(("vbsf_reg_sendfile: returns %#zx offFile=%#RX64\n", cbRet, offFile));
1276 }
1277 return cbRet;
1278}
1279#endif /* 2.5.30 <= LINUX_VERSION_CODE < 2.6.23 */
1280
1281
1282/*********************************************************************************************************************************
1283* File operations on regular files *
1284*********************************************************************************************************************************/
1285
1286/** Wrapper around put_page / page_cache_release. */
1287DECLINLINE(void) vbsf_put_page(struct page *pPage)
1288{
1289#if RTLNX_VER_MIN(4,6,0)
1290 put_page(pPage);
1291#else
1292 page_cache_release(pPage);
1293#endif
1294}
1295
1296
1297/** Wrapper around get_page / page_cache_get. */
1298DECLINLINE(void) vbsf_get_page(struct page *pPage)
1299{
1300#if RTLNX_VER_MIN(4,6,0)
1301 get_page(pPage);
1302#else
1303 page_cache_get(pPage);
1304#endif
1305}
1306
1307
1308/** Companion to vbsf_lock_user_pages(). */
1309static void vbsf_unlock_user_pages(struct page **papPages, size_t cPages, bool fSetDirty, bool fLockPgHack)
1310{
1311 /* We don't mark kernel pages dirty: */
1312 if (fLockPgHack)
1313 fSetDirty = false;
1314
1315 while (cPages-- > 0)
1316 {
1317 struct page *pPage = papPages[cPages];
1318 Assert((ssize_t)cPages >= 0);
1319 if (fSetDirty && !PageReserved(pPage))
1320 set_page_dirty(pPage);
1321 vbsf_put_page(pPage);
1322 }
1323}
1324
1325
1326/**
1327 * Worker for vbsf_lock_user_pages_failed_check_kernel() and
1328 * vbsf_iter_lock_pages().
1329 */
1330static int vbsf_lock_kernel_pages(uint8_t *pbStart, bool fWrite, size_t cPages, struct page **papPages)
1331{
1332 uintptr_t const uPtrFrom = (uintptr_t)pbStart;
1333 uintptr_t const uPtrLast = (uPtrFrom & ~(uintptr_t)PAGE_OFFSET_MASK) + (cPages << PAGE_SHIFT) - 1;
1334 uint8_t *pbPage = (uint8_t *)uPtrLast;
1335 size_t iPage = cPages;
1336
1337 /*
1338 * Touch the pages first (paranoia^2).
1339 */
1340 if (fWrite) {
1341 uint8_t volatile *pbProbe = (uint8_t volatile *)uPtrFrom;
1342 while (iPage-- > 0) {
1343 *pbProbe = *pbProbe;
1344 pbProbe += PAGE_SIZE;
1345 }
1346 } else {
1347 uint8_t const *pbProbe = (uint8_t const *)uPtrFrom;
1348 while (iPage-- > 0) {
1349 ASMProbeReadByte(pbProbe);
1350 pbProbe += PAGE_SIZE;
1351 }
1352 }
1353
1354 /*
1355 * Get the pages.
1356 * Note! Fixes here probably applies to rtR0MemObjNativeLockKernel as well.
1357 */
1358 iPage = cPages;
1359 if ( uPtrFrom >= (unsigned long)__va(0)
1360 && uPtrLast < (unsigned long)high_memory) {
1361 /* The physical page mapping area: */
1362 while (iPage-- > 0) {
1363 struct page *pPage = papPages[iPage] = virt_to_page(pbPage);
1364 vbsf_get_page(pPage);
1365 pbPage -= PAGE_SIZE;
1366 }
1367 } else {
1368 /* This is vmalloc or some such thing, so go thru page tables: */
1369 while (iPage-- > 0) {
1370 struct page *pPage = rtR0MemObjLinuxVirtToPage(pbPage);
1371 if (pPage) {
1372 papPages[iPage] = pPage;
1373 vbsf_get_page(pPage);
1374 pbPage -= PAGE_SIZE;
1375 } else {
1376 while (++iPage < cPages) {
1377 pPage = papPages[iPage];
1378 vbsf_put_page(pPage);
1379 }
1380 return -EFAULT;
1381 }
1382 }
1383 }
1384 return 0;
1385}
1386
1387
1388/**
1389 * Catches kernel_read() and kernel_write() calls and works around them.
1390 *
1391 * The file_operations::read and file_operations::write callbacks supposedly
1392 * hands us the user buffers to read into and write out of. To allow the kernel
1393 * to read and write without allocating buffers in userland, they kernel_read()
1394 * and kernel_write() increases the user space address limit before calling us
1395 * so that copyin/copyout won't reject it. Our problem is that get_user_pages()
1396 * works on the userspace address space structures and will not be fooled by an
1397 * increased addr_limit.
1398 *
1399 * This code tries to detect this situation and fake get_user_lock() for the
1400 * kernel buffer.
1401 */
1402static int vbsf_lock_user_pages_failed_check_kernel(uintptr_t uPtrFrom, size_t cPages, bool fWrite, int rcFailed,
1403 struct page **papPages, bool *pfLockPgHack)
1404{
1405 /*
1406 * Check that this is valid user memory that is actually in the kernel range.
1407 */
1408#if RTLNX_VER_MIN(5,10,0)
1409 if ( access_ok((void *)uPtrFrom, cPages << PAGE_SHIFT)
1410 && uPtrFrom >= TASK_SIZE_MAX)
1411#elif RTLNX_VER_MIN(5,0,0) || RTLNX_RHEL_MIN(8,1)
1412 if ( access_ok((void *)uPtrFrom, cPages << PAGE_SHIFT)
1413 && uPtrFrom >= USER_DS.seg)
1414#else
1415 if ( access_ok(fWrite ? VERIFY_WRITE : VERIFY_READ, (void *)uPtrFrom, cPages << PAGE_SHIFT)
1416 && uPtrFrom >= USER_DS.seg)
1417#endif
1418 {
1419 int rc = vbsf_lock_kernel_pages((uint8_t *)uPtrFrom, fWrite, cPages, papPages);
1420 if (rc == 0) {
1421 *pfLockPgHack = true;
1422 return 0;
1423 }
1424 }
1425
1426 return rcFailed;
1427}
1428
1429
1430/** Wrapper around get_user_pages. */
1431DECLINLINE(int) vbsf_lock_user_pages(uintptr_t uPtrFrom, size_t cPages, bool fWrite, struct page **papPages, bool *pfLockPgHack)
1432{
1433# if RTLNX_VER_MIN(4,9,0) \
1434 || (defined(CONFIG_SUSE_KERNEL) && RTLNX_VER_RANGE(4,4,73, 4,4,74) /** @todo Figure out when & what exactly. */) \
1435 || (defined(CONFIG_SUSE_KERNEL) && RTLNX_VER_RANGE(4,4,75, 4,4,90) /** @todo Figure out when & what exactly. */) \
1436 || (defined(CONFIG_SUSE_KERNEL) && RTLNX_VER_RANGE(4,4,92, 4,5,0) /** @todo Figure out when & what exactly. */)
1437 ssize_t cPagesLocked = get_user_pages_unlocked(uPtrFrom, cPages, papPages,
1438 fWrite ? FOLL_WRITE | FOLL_FORCE : FOLL_FORCE);
1439# elif RTLNX_VER_MIN(4,6,0)
1440 ssize_t cPagesLocked = get_user_pages_unlocked(uPtrFrom, cPages, fWrite, 1 /*force*/, papPages);
1441# elif RTLNX_VER_RANGE(4,4,168, 4,5,0)
1442 ssize_t cPagesLocked = get_user_pages_unlocked(current, current->mm, uPtrFrom, cPages, papPages,
1443 fWrite ? FOLL_WRITE | FOLL_FORCE : FOLL_FORCE);
1444# elif RTLNX_VER_MIN(4,0,0)
1445 ssize_t cPagesLocked = get_user_pages_unlocked(current, current->mm, uPtrFrom, cPages, fWrite, 1 /*force*/, papPages);
1446# else
1447 struct task_struct *pTask = current;
1448 ssize_t cPagesLocked;
1449 down_read(&pTask->mm->mmap_sem);
1450 cPagesLocked = get_user_pages(pTask, pTask->mm, uPtrFrom, cPages, fWrite, 1 /*force*/, papPages, NULL);
1451 up_read(&pTask->mm->mmap_sem);
1452# endif
1453 *pfLockPgHack = false;
1454 if (cPagesLocked == cPages)
1455 return 0;
1456
1457 /*
1458 * It failed.
1459 */
1460 if (cPagesLocked < 0)
1461 return vbsf_lock_user_pages_failed_check_kernel(uPtrFrom, cPages, fWrite, (int)cPagesLocked, papPages, pfLockPgHack);
1462
1463 vbsf_unlock_user_pages(papPages, cPagesLocked, false /*fSetDirty*/, false /*fLockPgHack*/);
1464
1465 /* We could use uPtrFrom + cPagesLocked to get the correct status here... */
1466 return -EFAULT;
1467}
1468
1469#if RTLNX_VER_MAX(5,10,0) /* No regular .read/.write for 5.10, only .read_iter/.write_iter or in-kernel reads/writes fail. */
1470
1471/**
1472 * Read function used when accessing files that are memory mapped.
1473 *
1474 * We read from the page cache here to present the a cohertent picture of the
1475 * the file content.
1476 */
1477static ssize_t vbsf_reg_read_mapped(struct file *file, char /*__user*/ *buf, size_t size, loff_t *off)
1478{
1479# if RTLNX_VER_MIN(3,16,0)
1480 struct iovec iov = { .iov_base = buf, .iov_len = size };
1481 struct iov_iter iter;
1482 struct kiocb kiocb;
1483 ssize_t cbRet;
1484
1485 init_sync_kiocb(&kiocb, file);
1486 kiocb.ki_pos = *off;
1487 iov_iter_init(&iter, READ, &iov, 1, size);
1488
1489 cbRet = generic_file_read_iter(&kiocb, &iter);
1490
1491 *off = kiocb.ki_pos;
1492 return cbRet;
1493
1494# elif RTLNX_VER_MIN(2,6,19)
1495 struct iovec iov = { .iov_base = buf, .iov_len = size };
1496 struct kiocb kiocb;
1497 ssize_t cbRet;
1498
1499 init_sync_kiocb(&kiocb, file);
1500 kiocb.ki_pos = *off;
1501
1502 cbRet = generic_file_aio_read(&kiocb, &iov, 1, *off);
1503 if (cbRet == -EIOCBQUEUED)
1504 cbRet = wait_on_sync_kiocb(&kiocb);
1505
1506 *off = kiocb.ki_pos;
1507 return cbRet;
1508
1509# else /* 2.6.18 or earlier: */
1510 return generic_file_read(file, buf, size, off);
1511# endif
1512}
1513
1514
1515/**
1516 * Fallback case of vbsf_reg_read() that locks the user buffers and let the host
1517 * write directly to them.
1518 */
1519static ssize_t vbsf_reg_read_locking(struct file *file, char /*__user*/ *buf, size_t size, loff_t *off,
1520 struct vbsf_super_info *pSuperInfo, struct vbsf_reg_info *sf_r)
1521{
1522 /*
1523 * Lock pages and execute the read, taking care not to pass the host
1524 * more than it can handle in one go or more than we care to allocate
1525 * page arrays for. The latter limit is set at just short of 32KB due
1526 * to how the physical heap works.
1527 */
1528 struct page *apPagesStack[16];
1529 struct page **papPages = &apPagesStack[0];
1530 struct page **papPagesFree = NULL;
1531 VBOXSFREADPGLSTREQ *pReq;
1532 loff_t offFile = *off;
1533 ssize_t cbRet = -ENOMEM;
1534 size_t cPages = (((uintptr_t)buf & PAGE_OFFSET_MASK) + size + PAGE_OFFSET_MASK) >> PAGE_SHIFT;
1535 size_t cMaxPages = RT_MIN(RT_MAX(pSuperInfo->cMaxIoPages, 1), cPages);
1536 bool fLockPgHack;
1537
1538 pReq = (VBOXSFREADPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFREADPGLSTREQ, PgLst.aPages[cMaxPages]));
1539 while (!pReq && cMaxPages > 4) {
1540 cMaxPages /= 2;
1541 pReq = (VBOXSFREADPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFREADPGLSTREQ, PgLst.aPages[cMaxPages]));
1542 }
1543 if (pReq && cMaxPages > RT_ELEMENTS(apPagesStack))
1544 papPagesFree = papPages = kmalloc(cMaxPages * sizeof(sizeof(papPages[0])), GFP_KERNEL);
1545 if (pReq && papPages) {
1546 cbRet = 0;
1547 for (;;) {
1548 /*
1549 * Figure out how much to process now and lock the user pages.
1550 */
1551 int rc;
1552 size_t cbChunk = (uintptr_t)buf & PAGE_OFFSET_MASK;
1553 pReq->PgLst.offFirstPage = (uint16_t)cbChunk;
1554 cPages = RT_ALIGN_Z(cbChunk + size, PAGE_SIZE) >> PAGE_SHIFT;
1555 if (cPages <= cMaxPages)
1556 cbChunk = size;
1557 else {
1558 cPages = cMaxPages;
1559 cbChunk = (cMaxPages << PAGE_SHIFT) - cbChunk;
1560 }
1561
1562 rc = vbsf_lock_user_pages((uintptr_t)buf, cPages, true /*fWrite*/, papPages, &fLockPgHack);
1563 if (rc == 0) {
1564 size_t iPage = cPages;
1565 while (iPage-- > 0)
1566 pReq->PgLst.aPages[iPage] = page_to_phys(papPages[iPage]);
1567 } else {
1568 cbRet = rc;
1569 break;
1570 }
1571
1572 /*
1573 * Issue the request and unlock the pages.
1574 */
1575 rc = VbglR0SfHostReqReadPgLst(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, offFile, cbChunk, cPages);
1576
1577 Assert(cPages <= cMaxPages);
1578 vbsf_unlock_user_pages(papPages, cPages, true /*fSetDirty*/, fLockPgHack);
1579
1580 if (RT_SUCCESS(rc)) {
1581 /*
1582 * Success, advance position and buffer.
1583 */
1584 uint32_t cbActual = pReq->Parms.cb32Read.u.value32;
1585 AssertStmt(cbActual <= cbChunk, cbActual = cbChunk);
1586 cbRet += cbActual;
1587 offFile += cbActual;
1588 buf = (uint8_t *)buf + cbActual;
1589 size -= cbActual;
1590
1591 /*
1592 * Are we done already? If so commit the new file offset.
1593 */
1594 if (!size || cbActual < cbChunk) {
1595 *off = offFile;
1596 break;
1597 }
1598 } else if (rc == VERR_NO_MEMORY && cMaxPages > 4) {
1599 /*
1600 * The host probably doesn't have enough heap to handle the
1601 * request, reduce the page count and retry.
1602 */
1603 cMaxPages /= 4;
1604 Assert(cMaxPages > 0);
1605 } else {
1606 /*
1607 * If we've successfully read stuff, return it rather than
1608 * the error. (Not sure if this is such a great idea...)
1609 */
1610 if (cbRet > 0) {
1611 SFLOGFLOW(("vbsf_reg_read: read at %#RX64 -> %Rrc; got cbRet=%#zx already\n", offFile, rc, cbRet));
1612 *off = offFile;
1613 } else {
1614 SFLOGFLOW(("vbsf_reg_read: read at %#RX64 -> %Rrc\n", offFile, rc));
1615 cbRet = -EPROTO;
1616 }
1617 break;
1618 }
1619 }
1620 }
1621 if (papPagesFree)
1622 kfree(papPages);
1623 if (pReq)
1624 VbglR0PhysHeapFree(pReq);
1625 SFLOGFLOW(("vbsf_reg_read: returns %zd (%#zx), *off=%RX64 [lock]\n", cbRet, cbRet, *off));
1626 return cbRet;
1627}
1628
1629
1630/**
1631 * Read from a regular file.
1632 *
1633 * @param file the file
1634 * @param buf the buffer
1635 * @param size length of the buffer
1636 * @param off offset within the file (in/out).
1637 * @returns the number of read bytes on success, Linux error code otherwise
1638 */
1639static ssize_t vbsf_reg_read(struct file *file, char /*__user*/ *buf, size_t size, loff_t *off)
1640{
1641 struct inode *inode = VBSF_GET_F_DENTRY(file)->d_inode;
1642 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
1643 struct vbsf_reg_info *sf_r = file->private_data;
1644 struct address_space *mapping = inode->i_mapping;
1645
1646 SFLOGFLOW(("vbsf_reg_read: inode=%p file=%p buf=%p size=%#zx off=%#llx\n", inode, file, buf, size, *off));
1647
1648 if (!S_ISREG(inode->i_mode)) {
1649 LogFunc(("read from non regular file %d\n", inode->i_mode));
1650 return -EINVAL;
1651 }
1652
1653 /** @todo XXX Check read permission according to inode->i_mode! */
1654
1655 if (!size)
1656 return 0;
1657
1658 /*
1659 * If there is a mapping and O_DIRECT isn't in effect, we must at a
1660 * heed dirty pages in the mapping and read from them. For simplicity
1661 * though, we just do page cache reading when there are writable
1662 * mappings around with any kind of pages loaded.
1663 */
1664 if (vbsf_should_use_cached_read(file, mapping, pSuperInfo))
1665 return vbsf_reg_read_mapped(file, buf, size, off);
1666
1667 /*
1668 * For small requests, try use an embedded buffer provided we get a heap block
1669 * that does not cross page boundraries (see host code).
1670 */
1671 if (size <= PAGE_SIZE / 4 * 3 - RT_UOFFSETOF(VBOXSFREADEMBEDDEDREQ, abData[0]) /* see allocator */) {
1672 uint32_t const cbReq = RT_UOFFSETOF(VBOXSFREADEMBEDDEDREQ, abData[0]) + size;
1673 VBOXSFREADEMBEDDEDREQ *pReq = (VBOXSFREADEMBEDDEDREQ *)VbglR0PhysHeapAlloc(cbReq);
1674 if (pReq) {
1675 if ((PAGE_SIZE - ((uintptr_t)pReq & PAGE_OFFSET_MASK)) >= cbReq) {
1676 ssize_t cbRet;
1677 int vrc = VbglR0SfHostReqReadEmbedded(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, *off, (uint32_t)size);
1678 if (RT_SUCCESS(vrc)) {
1679 cbRet = pReq->Parms.cb32Read.u.value32;
1680 AssertStmt(cbRet <= (ssize_t)size, cbRet = size);
1681 if (copy_to_user(buf, pReq->abData, cbRet) == 0)
1682 *off += cbRet;
1683 else
1684 cbRet = -EFAULT;
1685 } else
1686 cbRet = -EPROTO;
1687 VbglR0PhysHeapFree(pReq);
1688 SFLOGFLOW(("vbsf_reg_read: returns %zd (%#zx), *off=%RX64 [embed]\n", cbRet, cbRet, *off));
1689 return cbRet;
1690 }
1691 VbglR0PhysHeapFree(pReq);
1692 }
1693 }
1694
1695# if 0 /* Turns out this is slightly slower than locking the pages even for 4KB reads (4.19/amd64). */
1696 /*
1697 * For medium sized requests try use a bounce buffer.
1698 */
1699 if (size <= _64K /** @todo make this configurable? */) {
1700 void *pvBounce = kmalloc(size, GFP_KERNEL);
1701 if (pvBounce) {
1702 VBOXSFREADPGLSTREQ *pReq = (VBOXSFREADPGLSTREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq));
1703 if (pReq) {
1704 ssize_t cbRet;
1705 int vrc = VbglR0SfHostReqReadContig(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, *off,
1706 (uint32_t)size, pvBounce, virt_to_phys(pvBounce));
1707 if (RT_SUCCESS(vrc)) {
1708 cbRet = pReq->Parms.cb32Read.u.value32;
1709 AssertStmt(cbRet <= (ssize_t)size, cbRet = size);
1710 if (copy_to_user(buf, pvBounce, cbRet) == 0)
1711 *off += cbRet;
1712 else
1713 cbRet = -EFAULT;
1714 } else
1715 cbRet = -EPROTO;
1716 VbglR0PhysHeapFree(pReq);
1717 kfree(pvBounce);
1718 SFLOGFLOW(("vbsf_reg_read: returns %zd (%#zx), *off=%RX64 [bounce]\n", cbRet, cbRet, *off));
1719 return cbRet;
1720 }
1721 kfree(pvBounce);
1722 }
1723 }
1724# endif
1725
1726 return vbsf_reg_read_locking(file, buf, size, off, pSuperInfo, sf_r);
1727}
1728
1729#endif /* < 5.10.0 */
1730
1731/**
1732 * Helper the synchronizes the page cache content with something we just wrote
1733 * to the host.
1734 */
1735static void vbsf_reg_write_sync_page_cache(struct address_space *mapping, loff_t offFile, uint32_t cbRange,
1736 uint8_t const *pbSrcBuf, struct page **papSrcPages,
1737 uint32_t offSrcPage, size_t cSrcPages)
1738{
1739 Assert(offSrcPage < PAGE_SIZE);
1740 if (mapping && mapping->nrpages > 0) {
1741 /*
1742 * Work the pages in the write range.
1743 */
1744 while (cbRange > 0) {
1745 /*
1746 * Lookup the page at offFile. We're fine if there aren't
1747 * any there. We're skip if it's dirty or is being written
1748 * back, at least for now.
1749 */
1750 size_t const offDstPage = offFile & PAGE_OFFSET_MASK;
1751 size_t const cbToCopy = RT_MIN(PAGE_SIZE - offDstPage, cbRange);
1752 pgoff_t const idxPage = offFile >> PAGE_SHIFT;
1753 struct page *pDstPage = find_lock_page(mapping, idxPage);
1754 if (pDstPage) {
1755 if ( pDstPage->mapping == mapping /* ignore if re-purposed (paranoia) */
1756 && pDstPage->index == idxPage
1757 && !PageDirty(pDstPage) /* ignore if dirty */
1758 && !PageWriteback(pDstPage) /* ignore if being written back */ ) {
1759 /*
1760 * Map the page and do the copying.
1761 */
1762 uint8_t *pbDst = (uint8_t *)kmap(pDstPage);
1763 if (pbSrcBuf)
1764 memcpy(&pbDst[offDstPage], pbSrcBuf, cbToCopy);
1765 else {
1766 uint32_t const cbSrc0 = PAGE_SIZE - offSrcPage;
1767 uint8_t const *pbSrc = (uint8_t const *)kmap(papSrcPages[0]);
1768 AssertMsg(cSrcPages >= 1, ("offFile=%#llx cbRange=%#zx cbToCopy=%#zx\n", offFile, cbRange, cbToCopy));
1769 memcpy(&pbDst[offDstPage], &pbSrc[offSrcPage], RT_MIN(cbToCopy, cbSrc0));
1770 kunmap(papSrcPages[0]);
1771 if (cbToCopy > cbSrc0) {
1772 AssertMsg(cSrcPages >= 2, ("offFile=%#llx cbRange=%#zx cbToCopy=%#zx\n", offFile, cbRange, cbToCopy));
1773 pbSrc = (uint8_t const *)kmap(papSrcPages[1]);
1774 memcpy(&pbDst[offDstPage + cbSrc0], pbSrc, cbToCopy - cbSrc0);
1775 kunmap(papSrcPages[1]);
1776 }
1777 }
1778 kunmap(pDstPage);
1779 flush_dcache_page(pDstPage);
1780 if (cbToCopy == PAGE_SIZE)
1781 SetPageUptodate(pDstPage);
1782# if RTLNX_VER_MIN(2,4,10)
1783 mark_page_accessed(pDstPage);
1784# endif
1785 } else
1786 SFLOGFLOW(("vbsf_reg_write_sync_page_cache: Skipping page %p: mapping=%p (vs %p) writeback=%d offset=%#lx (vs%#lx)\n",
1787 pDstPage, pDstPage->mapping, mapping, PageWriteback(pDstPage), pDstPage->index, idxPage));
1788 unlock_page(pDstPage);
1789 vbsf_put_page(pDstPage);
1790 }
1791
1792 /*
1793 * Advance.
1794 */
1795 if (pbSrcBuf)
1796 pbSrcBuf += cbToCopy;
1797 else
1798 {
1799 offSrcPage += cbToCopy;
1800 Assert(offSrcPage < PAGE_SIZE * 2);
1801 if (offSrcPage >= PAGE_SIZE) {
1802 offSrcPage &= PAGE_OFFSET_MASK;
1803 papSrcPages++;
1804# ifdef VBOX_STRICT
1805 Assert(cSrcPages > 0);
1806 cSrcPages--;
1807# endif
1808 }
1809 }
1810 offFile += cbToCopy;
1811 cbRange -= cbToCopy;
1812 }
1813 }
1814 RT_NOREF(cSrcPages);
1815}
1816
1817#if RTLNX_VER_MAX(5,10,0) /* No regular .read/.write for 5.10, only .read_iter/.write_iter or in-kernel reads/writes fail. */
1818
1819/**
1820 * Fallback case of vbsf_reg_write() that locks the user buffers and let the host
1821 * write directly to them.
1822 */
1823static ssize_t vbsf_reg_write_locking(struct file *file, const char /*__user*/ *buf, size_t size, loff_t *off, loff_t offFile,
1824 struct inode *inode, struct vbsf_inode_info *sf_i,
1825 struct vbsf_super_info *pSuperInfo, struct vbsf_reg_info *sf_r)
1826{
1827 /*
1828 * Lock pages and execute the write, taking care not to pass the host
1829 * more than it can handle in one go or more than we care to allocate
1830 * page arrays for. The latter limit is set at just short of 32KB due
1831 * to how the physical heap works.
1832 */
1833 struct page *apPagesStack[16];
1834 struct page **papPages = &apPagesStack[0];
1835 struct page **papPagesFree = NULL;
1836 VBOXSFWRITEPGLSTREQ *pReq;
1837 ssize_t cbRet = -ENOMEM;
1838 size_t cPages = (((uintptr_t)buf & PAGE_OFFSET_MASK) + size + PAGE_OFFSET_MASK) >> PAGE_SHIFT;
1839 size_t cMaxPages = RT_MIN(RT_MAX(pSuperInfo->cMaxIoPages, 1), cPages);
1840 bool fLockPgHack;
1841
1842 pReq = (VBOXSFWRITEPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFWRITEPGLSTREQ, PgLst.aPages[cMaxPages]));
1843 while (!pReq && cMaxPages > 4) {
1844 cMaxPages /= 2;
1845 pReq = (VBOXSFWRITEPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFWRITEPGLSTREQ, PgLst.aPages[cMaxPages]));
1846 }
1847 if (pReq && cMaxPages > RT_ELEMENTS(apPagesStack))
1848 papPagesFree = papPages = kmalloc(cMaxPages * sizeof(sizeof(papPages[0])), GFP_KERNEL);
1849 if (pReq && papPages) {
1850 cbRet = 0;
1851 for (;;) {
1852 /*
1853 * Figure out how much to process now and lock the user pages.
1854 */
1855 int rc;
1856 size_t cbChunk = (uintptr_t)buf & PAGE_OFFSET_MASK;
1857 pReq->PgLst.offFirstPage = (uint16_t)cbChunk;
1858 cPages = RT_ALIGN_Z(cbChunk + size, PAGE_SIZE) >> PAGE_SHIFT;
1859 if (cPages <= cMaxPages)
1860 cbChunk = size;
1861 else {
1862 cPages = cMaxPages;
1863 cbChunk = (cMaxPages << PAGE_SHIFT) - cbChunk;
1864 }
1865
1866 rc = vbsf_lock_user_pages((uintptr_t)buf, cPages, false /*fWrite*/, papPages, &fLockPgHack);
1867 if (rc == 0) {
1868 size_t iPage = cPages;
1869 while (iPage-- > 0)
1870 pReq->PgLst.aPages[iPage] = page_to_phys(papPages[iPage]);
1871 } else {
1872 cbRet = rc;
1873 break;
1874 }
1875
1876 /*
1877 * Issue the request and unlock the pages.
1878 */
1879 rc = VbglR0SfHostReqWritePgLst(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, offFile, cbChunk, cPages);
1880 sf_i->ModificationTimeAtOurLastWrite = sf_i->ModificationTime;
1881 if (RT_SUCCESS(rc)) {
1882 /*
1883 * Success, advance position and buffer.
1884 */
1885 uint32_t cbActual = pReq->Parms.cb32Write.u.value32;
1886 AssertStmt(cbActual <= cbChunk, cbActual = cbChunk);
1887
1888 vbsf_reg_write_sync_page_cache(inode->i_mapping, offFile, cbActual, NULL /*pbKrnlBuf*/,
1889 papPages, (uintptr_t)buf & PAGE_OFFSET_MASK, cPages);
1890 Assert(cPages <= cMaxPages);
1891 vbsf_unlock_user_pages(papPages, cPages, false /*fSetDirty*/, fLockPgHack);
1892
1893 cbRet += cbActual;
1894 buf = (uint8_t *)buf + cbActual;
1895 size -= cbActual;
1896
1897 offFile += cbActual;
1898 if ((file->f_flags & O_APPEND) && (g_fSfFeatures & SHFL_FEATURE_WRITE_UPDATES_OFFSET))
1899 offFile = pReq->Parms.off64Write.u.value64;
1900 if (offFile > i_size_read(inode))
1901 i_size_write(inode, offFile);
1902
1903 sf_i->force_restat = 1; /* mtime (and size) may have changed */
1904
1905 /*
1906 * Are we done already? If so commit the new file offset.
1907 */
1908 if (!size || cbActual < cbChunk) {
1909 *off = offFile;
1910 break;
1911 }
1912 } else {
1913 vbsf_unlock_user_pages(papPages, cPages, false /*fSetDirty*/, fLockPgHack);
1914 if (rc == VERR_NO_MEMORY && cMaxPages > 4) {
1915 /*
1916 * The host probably doesn't have enough heap to handle the
1917 * request, reduce the page count and retry.
1918 */
1919 cMaxPages /= 4;
1920 Assert(cMaxPages > 0);
1921 } else {
1922 /*
1923 * If we've successfully written stuff, return it rather than
1924 * the error. (Not sure if this is such a great idea...)
1925 */
1926 if (cbRet > 0) {
1927 SFLOGFLOW(("vbsf_reg_write: write at %#RX64 -> %Rrc; got cbRet=%#zx already\n", offFile, rc, cbRet));
1928 *off = offFile;
1929 } else {
1930 SFLOGFLOW(("vbsf_reg_write: write at %#RX64 -> %Rrc\n", offFile, rc));
1931 cbRet = -EPROTO;
1932 }
1933 break;
1934 }
1935 }
1936 }
1937 }
1938 if (papPagesFree)
1939 kfree(papPages);
1940 if (pReq)
1941 VbglR0PhysHeapFree(pReq);
1942 SFLOGFLOW(("vbsf_reg_write: returns %zd (%#zx), *off=%RX64 [lock]\n", cbRet, cbRet, *off));
1943 return cbRet;
1944}
1945
1946
1947/**
1948 * Write to a regular file.
1949 *
1950 * @param file the file
1951 * @param buf the buffer
1952 * @param size length of the buffer
1953 * @param off offset within the file
1954 * @returns the number of written bytes on success, Linux error code otherwise
1955 */
1956static ssize_t vbsf_reg_write(struct file *file, const char *buf, size_t size, loff_t * off)
1957{
1958 struct inode *inode = VBSF_GET_F_DENTRY(file)->d_inode;
1959 struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(inode);
1960 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
1961 struct vbsf_reg_info *sf_r = file->private_data;
1962 struct address_space *mapping = inode->i_mapping;
1963 loff_t pos;
1964
1965 SFLOGFLOW(("vbsf_reg_write: inode=%p file=%p buf=%p size=%#zx off=%#llx\n", inode, file, buf, size, *off));
1966 Assert(sf_i);
1967 Assert(pSuperInfo);
1968 Assert(sf_r);
1969 AssertReturn(S_ISREG(inode->i_mode), -EINVAL);
1970
1971 pos = *off;
1972 if (file->f_flags & O_APPEND)
1973 pos = i_size_read(inode);
1974
1975 /** @todo XXX Check write permission according to inode->i_mode! */
1976
1977 if (!size) {
1978 if (file->f_flags & O_APPEND) /** @todo check if this is the consensus behavior... */
1979 *off = pos;
1980 return 0;
1981 }
1982
1983 /** @todo Implement the read-write caching mode. */
1984
1985 /*
1986 * If there are active writable mappings, coordinate with any
1987 * pending writes via those.
1988 */
1989 if ( mapping
1990 && mapping->nrpages > 0
1991 && mapping_writably_mapped(mapping)) {
1992# if RTLNX_VER_MIN(2,6,32)
1993 int err = filemap_fdatawait_range(mapping, pos, pos + size - 1);
1994 if (err)
1995 return err;
1996# else
1997 /** @todo ... */
1998# endif
1999 }
2000
2001 /*
2002 * For small requests, try use an embedded buffer provided we get a heap block
2003 * that does not cross page boundraries (see host code).
2004 */
2005 if (size <= PAGE_SIZE / 4 * 3 - RT_UOFFSETOF(VBOXSFWRITEEMBEDDEDREQ, abData[0]) /* see allocator */) {
2006 uint32_t const cbReq = RT_UOFFSETOF(VBOXSFWRITEEMBEDDEDREQ, abData[0]) + size;
2007 VBOXSFWRITEEMBEDDEDREQ *pReq = (VBOXSFWRITEEMBEDDEDREQ *)VbglR0PhysHeapAlloc(cbReq);
2008 if ( pReq
2009 && (PAGE_SIZE - ((uintptr_t)pReq & PAGE_OFFSET_MASK)) >= cbReq) {
2010 ssize_t cbRet;
2011 if (copy_from_user(pReq->abData, buf, size) == 0) {
2012 int vrc = VbglR0SfHostReqWriteEmbedded(pSuperInfo->map.root, pReq, sf_r->Handle.hHost,
2013 pos, (uint32_t)size);
2014 sf_i->ModificationTimeAtOurLastWrite = sf_i->ModificationTime;
2015 if (RT_SUCCESS(vrc)) {
2016 cbRet = pReq->Parms.cb32Write.u.value32;
2017 AssertStmt(cbRet <= (ssize_t)size, cbRet = size);
2018 vbsf_reg_write_sync_page_cache(mapping, pos, (uint32_t)cbRet, pReq->abData,
2019 NULL /*papSrcPages*/, 0 /*offSrcPage0*/, 0 /*cSrcPages*/);
2020 pos += cbRet;
2021 if ((file->f_flags & O_APPEND) && (g_fSfFeatures & SHFL_FEATURE_WRITE_UPDATES_OFFSET))
2022 pos = pReq->Parms.off64Write.u.value64;
2023 *off = pos;
2024 if (pos > i_size_read(inode))
2025 i_size_write(inode, pos);
2026 } else
2027 cbRet = -EPROTO;
2028 sf_i->force_restat = 1; /* mtime (and size) may have changed */
2029 } else
2030 cbRet = -EFAULT;
2031
2032 VbglR0PhysHeapFree(pReq);
2033 SFLOGFLOW(("vbsf_reg_write: returns %zd (%#zx), *off=%RX64 [embed]\n", cbRet, cbRet, *off));
2034 return cbRet;
2035 }
2036 if (pReq)
2037 VbglR0PhysHeapFree(pReq);
2038 }
2039
2040# if 0 /* Turns out this is slightly slower than locking the pages even for 4KB reads (4.19/amd64). */
2041 /*
2042 * For medium sized requests try use a bounce buffer.
2043 */
2044 if (size <= _64K /** @todo make this configurable? */) {
2045 void *pvBounce = kmalloc(size, GFP_KERNEL);
2046 if (pvBounce) {
2047 if (copy_from_user(pvBounce, buf, size) == 0) {
2048 VBOXSFWRITEPGLSTREQ *pReq = (VBOXSFWRITEPGLSTREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq));
2049 if (pReq) {
2050 ssize_t cbRet;
2051 int vrc = VbglR0SfHostReqWriteContig(pSuperInfo->map.root, pReq, sf_r->handle, pos,
2052 (uint32_t)size, pvBounce, virt_to_phys(pvBounce));
2053 sf_i->ModificationTimeAtOurLastWrite = sf_i->ModificationTime;
2054 if (RT_SUCCESS(vrc)) {
2055 cbRet = pReq->Parms.cb32Write.u.value32;
2056 AssertStmt(cbRet <= (ssize_t)size, cbRet = size);
2057 vbsf_reg_write_sync_page_cache(mapping, pos, (uint32_t)cbRet, (uint8_t const *)pvBounce,
2058 NULL /*papSrcPages*/, 0 /*offSrcPage0*/, 0 /*cSrcPages*/);
2059 pos += cbRet;
2060 *off = pos;
2061 if (pos > i_size_read(inode))
2062 i_size_write(inode, pos);
2063 } else
2064 cbRet = -EPROTO;
2065 sf_i->force_restat = 1; /* mtime (and size) may have changed */
2066 VbglR0PhysHeapFree(pReq);
2067 kfree(pvBounce);
2068 SFLOGFLOW(("vbsf_reg_write: returns %zd (%#zx), *off=%RX64 [bounce]\n", cbRet, cbRet, *off));
2069 return cbRet;
2070 }
2071 kfree(pvBounce);
2072 } else {
2073 kfree(pvBounce);
2074 SFLOGFLOW(("vbsf_reg_write: returns -EFAULT, *off=%RX64 [bounce]\n", *off));
2075 return -EFAULT;
2076 }
2077 }
2078 }
2079# endif
2080
2081 return vbsf_reg_write_locking(file, buf, size, off, pos, inode, sf_i, pSuperInfo, sf_r);
2082}
2083
2084#endif /* < 5.10.0 */
2085#if RTLNX_VER_MIN(2,6,19)
2086
2087/**
2088 * Companion to vbsf_iter_lock_pages().
2089 */
2090DECLINLINE(void) vbsf_iter_unlock_pages(struct iov_iter *iter, struct page **papPages, size_t cPages, bool fSetDirty)
2091{
2092 /* We don't mark kernel pages dirty (KVECs, BVECs, PIPEs): */
2093 if (!iter_is_iovec(iter))
2094 fSetDirty = false;
2095
2096 while (cPages-- > 0)
2097 {
2098 struct page *pPage = papPages[cPages];
2099 if (fSetDirty && !PageReserved(pPage))
2100 set_page_dirty(pPage);
2101 vbsf_put_page(pPage);
2102 }
2103}
2104
2105
2106/**
2107 * Locks up to @a cMaxPages from the I/O vector iterator, advancing the
2108 * iterator.
2109 *
2110 * @returns 0 on success, negative errno value on failure.
2111 * @param iter The iterator to lock pages from.
2112 * @param fWrite Whether to write (true) or read (false) lock the pages.
2113 * @param pStash Where we stash peek results.
2114 * @param cMaxPages The maximum number of pages to get.
2115 * @param papPages Where to return the locked pages.
2116 * @param pcPages Where to return the number of pages.
2117 * @param poffPage0 Where to return the offset into the first page.
2118 * @param pcbChunk Where to return the number of bytes covered.
2119 */
2120static int vbsf_iter_lock_pages(struct iov_iter *iter, bool fWrite, struct vbsf_iter_stash *pStash, size_t cMaxPages,
2121 struct page **papPages, size_t *pcPages, size_t *poffPage0, size_t *pcbChunk)
2122{
2123 size_t cbChunk = 0;
2124 size_t cPages = 0;
2125 size_t offPage0 = 0;
2126 int rc = 0;
2127
2128 Assert(iov_iter_count(iter) + pStash->cb > 0);
2129 if (!(iter->type & ITER_KVEC)) {
2130 /*
2131 * Do we have a stashed page?
2132 */
2133 if (pStash->pPage) {
2134 papPages[0] = pStash->pPage;
2135 offPage0 = pStash->off;
2136 cbChunk = pStash->cb;
2137 cPages = 1;
2138 pStash->pPage = NULL;
2139 pStash->off = 0;
2140 pStash->cb = 0;
2141 if ( offPage0 + cbChunk < PAGE_SIZE
2142 || iov_iter_count(iter) == 0) {
2143 *poffPage0 = offPage0;
2144 *pcbChunk = cbChunk;
2145 *pcPages = cPages;
2146 SFLOGFLOW(("vbsf_iter_lock_pages: returns %d - cPages=%#zx offPage0=%#zx cbChunk=%zx (stashed)\n",
2147 rc, cPages, offPage0, cbChunk));
2148 return 0;
2149 }
2150 cMaxPages -= 1;
2151 SFLOG3(("vbsf_iter_lock_pages: Picked up stashed page: %#zx LB %#zx\n", offPage0, cbChunk));
2152 } else {
2153# if RTLNX_VER_MAX(4,11,0)
2154 /*
2155 * Copy out our starting point to assist rewinding.
2156 */
2157 pStash->offFromEnd = iov_iter_count(iter);
2158 pStash->Copy = *iter;
2159# endif
2160 }
2161
2162 /*
2163 * Get pages segment by segment.
2164 */
2165 do {
2166 /*
2167 * Make a special case of the first time thru here, since that's
2168 * the most typical scenario.
2169 */
2170 ssize_t cbSegRet;
2171 if (cPages == 0) {
2172# if RTLNX_VER_MAX(3,19,0)
2173 while (!iov_iter_single_seg_count(iter)) /* Old code didn't skip empty segments which caused EFAULTs. */
2174 iov_iter_advance(iter, 0);
2175# endif
2176 cbSegRet = iov_iter_get_pages(iter, papPages, iov_iter_count(iter), cMaxPages, &offPage0);
2177 if (cbSegRet > 0) {
2178 iov_iter_advance(iter, cbSegRet);
2179 cbChunk = (size_t)cbSegRet;
2180 cPages = RT_ALIGN_Z(offPage0 + cbSegRet, PAGE_SIZE) >> PAGE_SHIFT;
2181 cMaxPages -= cPages;
2182 SFLOG3(("vbsf_iter_lock_pages: iov_iter_get_pages -> %#zx @ %#zx; %#zx pages [first]\n", cbSegRet, offPage0, cPages));
2183 if ( cMaxPages == 0
2184 || ((offPage0 + (size_t)cbSegRet) & PAGE_OFFSET_MASK))
2185 break;
2186 } else {
2187 AssertStmt(cbSegRet < 0, cbSegRet = -EFAULT);
2188 rc = (int)cbSegRet;
2189 break;
2190 }
2191 } else {
2192 /*
2193 * Probe first page of new segment to check that we've got a zero offset and
2194 * can continue on the current chunk. Stash the page if the offset isn't zero.
2195 */
2196 size_t offPgProbe;
2197 size_t cbSeg = iov_iter_single_seg_count(iter);
2198 while (!cbSeg) {
2199 iov_iter_advance(iter, 0);
2200 cbSeg = iov_iter_single_seg_count(iter);
2201 }
2202 cbSegRet = iov_iter_get_pages(iter, &papPages[cPages], iov_iter_count(iter), 1, &offPgProbe);
2203 if (cbSegRet > 0) {
2204 iov_iter_advance(iter, cbSegRet); /** @todo maybe not do this if we stash the page? */
2205 Assert(offPgProbe + cbSegRet <= PAGE_SIZE);
2206 if (offPgProbe == 0) {
2207 cbChunk += cbSegRet;
2208 cPages += 1;
2209 cMaxPages -= 1;
2210 SFLOG3(("vbsf_iter_lock_pages: iov_iter_get_pages(1) -> %#zx @ %#zx\n", cbSegRet, offPgProbe));
2211 if ( cMaxPages == 0
2212 || cbSegRet != PAGE_SIZE)
2213 break;
2214
2215 /*
2216 * Get the rest of the segment (if anything remaining).
2217 */
2218 cbSeg -= cbSegRet;
2219 if (cbSeg > 0) {
2220 cbSegRet = iov_iter_get_pages(iter, &papPages[cPages], iov_iter_count(iter), cMaxPages, &offPgProbe);
2221 if (cbSegRet > 0) {
2222 size_t const cPgRet = RT_ALIGN_Z((size_t)cbSegRet, PAGE_SIZE) >> PAGE_SHIFT;
2223 Assert(offPgProbe == 0);
2224 iov_iter_advance(iter, cbSegRet);
2225 SFLOG3(("vbsf_iter_lock_pages: iov_iter_get_pages() -> %#zx; %#zx pages\n", cbSegRet, cPgRet));
2226 cPages += cPgRet;
2227 cMaxPages -= cPgRet;
2228 cbChunk += cbSegRet;
2229 if ( cMaxPages == 0
2230 || ((size_t)cbSegRet & PAGE_OFFSET_MASK))
2231 break;
2232 } else {
2233 AssertStmt(cbSegRet < 0, cbSegRet = -EFAULT);
2234 rc = (int)cbSegRet;
2235 break;
2236 }
2237 }
2238 } else {
2239 /* The segment didn't start at a page boundrary, so stash it for
2240 the next round: */
2241 SFLOGFLOW(("vbsf_iter_lock_pages: iov_iter_get_pages(1) -> %#zx @ %#zx; stashed\n", cbSegRet, offPgProbe));
2242 Assert(papPages[cPages]);
2243 pStash->pPage = papPages[cPages];
2244 pStash->off = offPgProbe;
2245 pStash->cb = cbSegRet;
2246 break;
2247 }
2248 } else {
2249 AssertStmt(cbSegRet < 0, cbSegRet = -EFAULT);
2250 rc = (int)cbSegRet;
2251 break;
2252 }
2253 }
2254 Assert(cMaxPages > 0);
2255 } while (iov_iter_count(iter) > 0);
2256
2257 } else {
2258 /*
2259 * The silly iov_iter_get_pages_alloc() function doesn't handle KVECs,
2260 * so everyone needs to do that by themselves.
2261 *
2262 * Note! Fixes here may apply to rtR0MemObjNativeLockKernel()
2263 * and vbsf_lock_user_pages_failed_check_kernel() as well.
2264 */
2265# if RTLNX_VER_MAX(4,11,0)
2266 pStash->offFromEnd = iov_iter_count(iter);
2267 pStash->Copy = *iter;
2268# endif
2269 do {
2270 uint8_t *pbBuf;
2271 size_t offStart;
2272 size_t cPgSeg;
2273
2274 size_t cbSeg = iov_iter_single_seg_count(iter);
2275 while (!cbSeg) {
2276 iov_iter_advance(iter, 0);
2277 cbSeg = iov_iter_single_seg_count(iter);
2278 }
2279
2280# if RTLNX_VER_MIN(3,19,0)
2281 pbBuf = iter->kvec->iov_base + iter->iov_offset;
2282# else
2283 pbBuf = iter->iov->iov_base + iter->iov_offset;
2284# endif
2285 offStart = (uintptr_t)pbBuf & PAGE_OFFSET_MASK;
2286 if (!cPages)
2287 offPage0 = offStart;
2288 else if (offStart)
2289 break;
2290
2291 cPgSeg = RT_ALIGN_Z(cbSeg, PAGE_SIZE) >> PAGE_SHIFT;
2292 if (cPgSeg > cMaxPages) {
2293 cPgSeg = cMaxPages;
2294 cbSeg = (cPgSeg << PAGE_SHIFT) - offStart;
2295 }
2296
2297 rc = vbsf_lock_kernel_pages(pbBuf, fWrite, cPgSeg, &papPages[cPages]);
2298 if (rc == 0) {
2299 iov_iter_advance(iter, cbSeg);
2300 cbChunk += cbSeg;
2301 cPages += cPgSeg;
2302 cMaxPages -= cPgSeg;
2303 if ( cMaxPages == 0
2304 || ((offStart + cbSeg) & PAGE_OFFSET_MASK) != 0)
2305 break;
2306 } else
2307 break;
2308 } while (iov_iter_count(iter) > 0);
2309 }
2310
2311 /*
2312 * Clean up if we failed; set return values.
2313 */
2314 if (rc == 0) {
2315 /* likely */
2316 } else {
2317 if (cPages > 0)
2318 vbsf_iter_unlock_pages(iter, papPages, cPages, false /*fSetDirty*/);
2319 offPage0 = cbChunk = cPages = 0;
2320 }
2321 *poffPage0 = offPage0;
2322 *pcbChunk = cbChunk;
2323 *pcPages = cPages;
2324 SFLOGFLOW(("vbsf_iter_lock_pages: returns %d - cPages=%#zx offPage0=%#zx cbChunk=%zx\n", rc, cPages, offPage0, cbChunk));
2325 return rc;
2326}
2327
2328
2329/**
2330 * Rewinds the I/O vector.
2331 */
2332static bool vbsf_iter_rewind(struct iov_iter *iter, struct vbsf_iter_stash *pStash, size_t cbToRewind, size_t cbChunk)
2333{
2334 size_t cbExtra;
2335 if (!pStash->pPage) {
2336 cbExtra = 0;
2337 } else {
2338 cbExtra = pStash->cb;
2339 vbsf_put_page(pStash->pPage);
2340 pStash->pPage = NULL;
2341 pStash->cb = 0;
2342 pStash->off = 0;
2343 }
2344
2345# if RTLNX_VER_MIN(4,11,0) || RTLNX_VER_MAX(3,16,0)
2346 iov_iter_revert(iter, cbToRewind + cbExtra);
2347 return true;
2348# else
2349 /** @todo impl this */
2350 return false;
2351# endif
2352}
2353
2354
2355/**
2356 * Cleans up the page locking stash.
2357 */
2358DECLINLINE(void) vbsf_iter_cleanup_stash(struct iov_iter *iter, struct vbsf_iter_stash *pStash)
2359{
2360 if (pStash->pPage)
2361 vbsf_iter_rewind(iter, pStash, 0, 0);
2362}
2363
2364
2365/**
2366 * Calculates the longest span of pages we could transfer to the host in a
2367 * single request.
2368 *
2369 * @returns Page count, non-zero.
2370 * @param iter The I/O vector iterator to inspect.
2371 */
2372static size_t vbsf_iter_max_span_of_pages(struct iov_iter *iter)
2373{
2374 size_t cPages;
2375# if RTLNX_VER_MIN(3,16,0)
2376 if (iter_is_iovec(iter) || (iter->type & ITER_KVEC)) {
2377#endif
2378 const struct iovec *pCurIov = iter->iov;
2379 size_t cLeft = iter->nr_segs;
2380 size_t cPagesSpan = 0;
2381
2382 /* iovect and kvec are identical, except for the __user tagging of iov_base. */
2383 AssertCompileMembersSameSizeAndOffset(struct iovec, iov_base, struct kvec, iov_base);
2384 AssertCompileMembersSameSizeAndOffset(struct iovec, iov_len, struct kvec, iov_len);
2385 AssertCompile(sizeof(struct iovec) == sizeof(struct kvec));
2386
2387 cPages = 1;
2388 AssertReturn(cLeft > 0, cPages);
2389
2390 /* Special case: segment offset. */
2391 if (iter->iov_offset > 0) {
2392 if (iter->iov_offset < pCurIov->iov_len) {
2393 size_t const cbSegLeft = pCurIov->iov_len - iter->iov_offset;
2394 size_t const offPage0 = ((uintptr_t)pCurIov->iov_base + iter->iov_offset) & PAGE_OFFSET_MASK;
2395 cPages = cPagesSpan = RT_ALIGN_Z(offPage0 + cbSegLeft, PAGE_SIZE) >> PAGE_SHIFT;
2396 if ((offPage0 + cbSegLeft) & PAGE_OFFSET_MASK)
2397 cPagesSpan = 0;
2398 }
2399 SFLOGFLOW(("vbsf_iter: seg[0]= %p LB %#zx\n", pCurIov->iov_base, pCurIov->iov_len));
2400 pCurIov++;
2401 cLeft--;
2402 }
2403
2404 /* Full segments. */
2405 while (cLeft-- > 0) {
2406 if (pCurIov->iov_len > 0) {
2407 size_t const offPage0 = (uintptr_t)pCurIov->iov_base & PAGE_OFFSET_MASK;
2408 if (offPage0 == 0) {
2409 if (!(pCurIov->iov_len & PAGE_OFFSET_MASK)) {
2410 cPagesSpan += pCurIov->iov_len >> PAGE_SHIFT;
2411 } else {
2412 cPagesSpan += RT_ALIGN_Z(pCurIov->iov_len, PAGE_SIZE) >> PAGE_SHIFT;
2413 if (cPagesSpan > cPages)
2414 cPages = cPagesSpan;
2415 cPagesSpan = 0;
2416 }
2417 } else {
2418 if (cPagesSpan > cPages)
2419 cPages = cPagesSpan;
2420 if (!((offPage0 + pCurIov->iov_len) & PAGE_OFFSET_MASK)) {
2421 cPagesSpan = pCurIov->iov_len >> PAGE_SHIFT;
2422 } else {
2423 cPagesSpan += RT_ALIGN_Z(offPage0 + pCurIov->iov_len, PAGE_SIZE) >> PAGE_SHIFT;
2424 if (cPagesSpan > cPages)
2425 cPages = cPagesSpan;
2426 cPagesSpan = 0;
2427 }
2428 }
2429 }
2430 SFLOGFLOW(("vbsf_iter: seg[%u]= %p LB %#zx\n", iter->nr_segs - cLeft, pCurIov->iov_base, pCurIov->iov_len));
2431 pCurIov++;
2432 }
2433 if (cPagesSpan > cPages)
2434 cPages = cPagesSpan;
2435# if RTLNX_VER_MIN(3,16,0)
2436 } else {
2437 /* Won't bother with accurate counts for the next two types, just make
2438 some rough estimates (does pipes have segments?): */
2439 size_t cSegs = iter->type & ITER_BVEC ? RT_MAX(1, iter->nr_segs) : 1;
2440 cPages = (iov_iter_count(iter) + (PAGE_SIZE * 2 - 2) * cSegs) >> PAGE_SHIFT;
2441 }
2442# endif
2443 SFLOGFLOW(("vbsf_iter_max_span_of_pages: returns %#zx\n", cPages));
2444 return cPages;
2445}
2446
2447
2448/**
2449 * Worker for vbsf_reg_read_iter() that deals with larger reads using page
2450 * locking.
2451 */
2452static ssize_t vbsf_reg_read_iter_locking(struct kiocb *kio, struct iov_iter *iter, size_t cbToRead,
2453 struct vbsf_super_info *pSuperInfo, struct vbsf_reg_info *sf_r)
2454{
2455 /*
2456 * Estimate how many pages we may possible submit in a single request so
2457 * that we can allocate matching request buffer and page array.
2458 */
2459 struct page *apPagesStack[16];
2460 struct page **papPages = &apPagesStack[0];
2461 struct page **papPagesFree = NULL;
2462 VBOXSFREADPGLSTREQ *pReq;
2463 ssize_t cbRet = 0;
2464 size_t cMaxPages = vbsf_iter_max_span_of_pages(iter);
2465 cMaxPages = RT_MIN(RT_MAX(pSuperInfo->cMaxIoPages, 2), cMaxPages);
2466
2467 pReq = (VBOXSFREADPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFREADPGLSTREQ, PgLst.aPages[cMaxPages]));
2468 while (!pReq && cMaxPages > 4) {
2469 cMaxPages /= 2;
2470 pReq = (VBOXSFREADPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFREADPGLSTREQ, PgLst.aPages[cMaxPages]));
2471 }
2472 if (pReq && cMaxPages > RT_ELEMENTS(apPagesStack))
2473 papPagesFree = papPages = kmalloc(cMaxPages * sizeof(sizeof(papPages[0])), GFP_KERNEL);
2474 if (pReq && papPages) {
2475
2476 /*
2477 * The read loop.
2478 */
2479 struct vbsf_iter_stash Stash = VBSF_ITER_STASH_INITIALIZER;
2480 do {
2481 /*
2482 * Grab as many pages as we can. This means that if adjacent
2483 * segments both starts and ends at a page boundrary, we can
2484 * do them both in the same transfer from the host.
2485 */
2486 size_t cPages = 0;
2487 size_t cbChunk = 0;
2488 size_t offPage0 = 0;
2489 int rc = vbsf_iter_lock_pages(iter, true /*fWrite*/, &Stash, cMaxPages, papPages, &cPages, &offPage0, &cbChunk);
2490 if (rc == 0) {
2491 size_t iPage = cPages;
2492 while (iPage-- > 0)
2493 pReq->PgLst.aPages[iPage] = page_to_phys(papPages[iPage]);
2494 pReq->PgLst.offFirstPage = (uint16_t)offPage0;
2495 AssertStmt(cbChunk <= cbToRead, cbChunk = cbToRead);
2496 } else {
2497 cbRet = rc;
2498 break;
2499 }
2500
2501 /*
2502 * Issue the request and unlock the pages.
2503 */
2504 rc = VbglR0SfHostReqReadPgLst(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, kio->ki_pos, cbChunk, cPages);
2505 SFLOGFLOW(("vbsf_reg_read_iter_locking: VbglR0SfHostReqReadPgLst -> %d (cbActual=%#x cbChunk=%#zx of %#zx cPages=%#zx offPage0=%#x\n",
2506 rc, pReq->Parms.cb32Read.u.value32, cbChunk, cbToRead, cPages, offPage0));
2507
2508 vbsf_iter_unlock_pages(iter, papPages, cPages, true /*fSetDirty*/);
2509
2510 if (RT_SUCCESS(rc)) {
2511 /*
2512 * Success, advance position and buffer.
2513 */
2514 uint32_t cbActual = pReq->Parms.cb32Read.u.value32;
2515 AssertStmt(cbActual <= cbChunk, cbActual = cbChunk);
2516 cbRet += cbActual;
2517 kio->ki_pos += cbActual;
2518 cbToRead -= cbActual;
2519
2520 /*
2521 * Are we done already?
2522 */
2523 if (!cbToRead)
2524 break;
2525 if (cbActual < cbChunk) { /* We ASSUME end-of-file here. */
2526 if (vbsf_iter_rewind(iter, &Stash, cbChunk - cbActual, cbActual))
2527 iov_iter_truncate(iter, 0);
2528 break;
2529 }
2530 } else {
2531 /*
2532 * Try rewind the iter structure.
2533 */
2534 bool const fRewindOkay = vbsf_iter_rewind(iter, &Stash, cbChunk, cbChunk);
2535 if (rc == VERR_NO_MEMORY && cMaxPages > 4 && fRewindOkay) {
2536 /*
2537 * The host probably doesn't have enough heap to handle the
2538 * request, reduce the page count and retry.
2539 */
2540 cMaxPages /= 4;
2541 Assert(cMaxPages > 0);
2542 } else {
2543 /*
2544 * If we've successfully read stuff, return it rather than
2545 * the error. (Not sure if this is such a great idea...)
2546 */
2547 if (cbRet <= 0)
2548 cbRet = -EPROTO;
2549 break;
2550 }
2551 }
2552 } while (cbToRead > 0);
2553
2554 vbsf_iter_cleanup_stash(iter, &Stash);
2555 }
2556 else
2557 cbRet = -ENOMEM;
2558 if (papPagesFree)
2559 kfree(papPages);
2560 if (pReq)
2561 VbglR0PhysHeapFree(pReq);
2562 SFLOGFLOW(("vbsf_reg_read_iter_locking: returns %#zx (%zd)\n", cbRet, cbRet));
2563 return cbRet;
2564}
2565
2566
2567/**
2568 * Read into I/O vector iterator.
2569 *
2570 * @returns Number of bytes read on success, negative errno on error.
2571 * @param kio The kernel I/O control block (or something like that).
2572 * @param iter The I/O vector iterator describing the buffer.
2573 */
2574# if RTLNX_VER_MIN(3,16,0)
2575static ssize_t vbsf_reg_read_iter(struct kiocb *kio, struct iov_iter *iter)
2576# else
2577static ssize_t vbsf_reg_aio_read(struct kiocb *kio, const struct iovec *iov, unsigned long cSegs, loff_t offFile)
2578# endif
2579{
2580# if RTLNX_VER_MAX(3,16,0)
2581 struct vbsf_iov_iter fake_iter = VBSF_IOV_ITER_INITIALIZER(cSegs, iov, 0 /*write*/);
2582 struct vbsf_iov_iter *iter = &fake_iter;
2583# endif
2584 size_t cbToRead = iov_iter_count(iter);
2585 struct inode *inode = VBSF_GET_F_DENTRY(kio->ki_filp)->d_inode;
2586 struct address_space *mapping = inode->i_mapping;
2587
2588 struct vbsf_reg_info *sf_r = kio->ki_filp->private_data;
2589 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
2590
2591 SFLOGFLOW(("vbsf_reg_read_iter: inode=%p file=%p size=%#zx off=%#llx type=%#x\n",
2592 inode, kio->ki_filp, cbToRead, kio->ki_pos, iter->type));
2593 AssertReturn(S_ISREG(inode->i_mode), -EINVAL);
2594
2595 /*
2596 * Do we have anything at all to do here?
2597 */
2598 if (!cbToRead)
2599 return 0;
2600
2601 /*
2602 * If there is a mapping and O_DIRECT isn't in effect, we must at a
2603 * heed dirty pages in the mapping and read from them. For simplicity
2604 * though, we just do page cache reading when there are writable
2605 * mappings around with any kind of pages loaded.
2606 */
2607 if (vbsf_should_use_cached_read(kio->ki_filp, mapping, pSuperInfo)) {
2608# if RTLNX_VER_MIN(3,16,0)
2609 return generic_file_read_iter(kio, iter);
2610# else
2611 return generic_file_aio_read(kio, iov, cSegs, offFile);
2612# endif
2613 }
2614
2615 /*
2616 * Now now we reject async I/O requests.
2617 */
2618 if (!is_sync_kiocb(kio)) {
2619 SFLOGFLOW(("vbsf_reg_read_iter: async I/O not yet supported\n")); /** @todo extend FsPerf with AIO tests. */
2620 return -EOPNOTSUPP;
2621 }
2622
2623 /*
2624 * For small requests, try use an embedded buffer provided we get a heap block
2625 * that does not cross page boundraries (see host code).
2626 */
2627 if (cbToRead <= PAGE_SIZE / 4 * 3 - RT_UOFFSETOF(VBOXSFREADEMBEDDEDREQ, abData[0]) /* see allocator */) {
2628 uint32_t const cbReq = RT_UOFFSETOF(VBOXSFREADEMBEDDEDREQ, abData[0]) + cbToRead;
2629 VBOXSFREADEMBEDDEDREQ *pReq = (VBOXSFREADEMBEDDEDREQ *)VbglR0PhysHeapAlloc(cbReq);
2630 if (pReq) {
2631 if ((PAGE_SIZE - ((uintptr_t)pReq & PAGE_OFFSET_MASK)) >= cbReq) {
2632 ssize_t cbRet;
2633 int vrc = VbglR0SfHostReqReadEmbedded(pSuperInfo->map.root, pReq, sf_r->Handle.hHost,
2634 kio->ki_pos, (uint32_t)cbToRead);
2635 if (RT_SUCCESS(vrc)) {
2636 cbRet = pReq->Parms.cb32Read.u.value32;
2637 AssertStmt(cbRet <= (ssize_t)cbToRead, cbRet = cbToRead);
2638 if (copy_to_iter(pReq->abData, cbRet, iter) == cbRet) {
2639 kio->ki_pos += cbRet;
2640 if (cbRet < cbToRead)
2641 iov_iter_truncate(iter, 0);
2642 } else
2643 cbRet = -EFAULT;
2644 } else
2645 cbRet = -EPROTO;
2646 VbglR0PhysHeapFree(pReq);
2647 SFLOGFLOW(("vbsf_reg_read_iter: returns %#zx (%zd)\n", cbRet, cbRet));
2648 return cbRet;
2649 }
2650 VbglR0PhysHeapFree(pReq);
2651 }
2652 }
2653
2654 /*
2655 * Otherwise do the page locking thing.
2656 */
2657 return vbsf_reg_read_iter_locking(kio, iter, cbToRead, pSuperInfo, sf_r);
2658}
2659
2660
2661/**
2662 * Worker for vbsf_reg_write_iter() that deals with larger writes using page
2663 * locking.
2664 */
2665static ssize_t vbsf_reg_write_iter_locking(struct kiocb *kio, struct iov_iter *iter, size_t cbToWrite, loff_t offFile,
2666 struct vbsf_super_info *pSuperInfo, struct vbsf_reg_info *sf_r, struct inode *inode,
2667 struct vbsf_inode_info *sf_i, struct address_space *mapping, bool fAppend)
2668{
2669 /*
2670 * Estimate how many pages we may possible submit in a single request so
2671 * that we can allocate matching request buffer and page array.
2672 */
2673 struct page *apPagesStack[16];
2674 struct page **papPages = &apPagesStack[0];
2675 struct page **papPagesFree = NULL;
2676 VBOXSFWRITEPGLSTREQ *pReq;
2677 ssize_t cbRet = 0;
2678 size_t cMaxPages = vbsf_iter_max_span_of_pages(iter);
2679 cMaxPages = RT_MIN(RT_MAX(pSuperInfo->cMaxIoPages, 2), cMaxPages);
2680
2681 pReq = (VBOXSFWRITEPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFWRITEPGLSTREQ, PgLst.aPages[cMaxPages]));
2682 while (!pReq && cMaxPages > 4) {
2683 cMaxPages /= 2;
2684 pReq = (VBOXSFWRITEPGLSTREQ *)VbglR0PhysHeapAlloc(RT_UOFFSETOF_DYN(VBOXSFWRITEPGLSTREQ, PgLst.aPages[cMaxPages]));
2685 }
2686 if (pReq && cMaxPages > RT_ELEMENTS(apPagesStack))
2687 papPagesFree = papPages = kmalloc(cMaxPages * sizeof(sizeof(papPages[0])), GFP_KERNEL);
2688 if (pReq && papPages) {
2689
2690 /*
2691 * The write loop.
2692 */
2693 struct vbsf_iter_stash Stash = VBSF_ITER_STASH_INITIALIZER;
2694 do {
2695 /*
2696 * Grab as many pages as we can. This means that if adjacent
2697 * segments both starts and ends at a page boundrary, we can
2698 * do them both in the same transfer from the host.
2699 */
2700 size_t cPages = 0;
2701 size_t cbChunk = 0;
2702 size_t offPage0 = 0;
2703 int rc = vbsf_iter_lock_pages(iter, false /*fWrite*/, &Stash, cMaxPages, papPages, &cPages, &offPage0, &cbChunk);
2704 if (rc == 0) {
2705 size_t iPage = cPages;
2706 while (iPage-- > 0)
2707 pReq->PgLst.aPages[iPage] = page_to_phys(papPages[iPage]);
2708 pReq->PgLst.offFirstPage = (uint16_t)offPage0;
2709 AssertStmt(cbChunk <= cbToWrite, cbChunk = cbToWrite);
2710 } else {
2711 cbRet = rc;
2712 break;
2713 }
2714
2715 /*
2716 * Issue the request and unlock the pages.
2717 */
2718 rc = VbglR0SfHostReqWritePgLst(pSuperInfo->map.root, pReq, sf_r->Handle.hHost, offFile, cbChunk, cPages);
2719 sf_i->ModificationTimeAtOurLastWrite = sf_i->ModificationTime;
2720 SFLOGFLOW(("vbsf_reg_write_iter_locking: VbglR0SfHostReqWritePgLst -> %d (cbActual=%#x cbChunk=%#zx of %#zx cPages=%#zx offPage0=%#x\n",
2721 rc, pReq->Parms.cb32Write.u.value32, cbChunk, cbToWrite, cPages, offPage0));
2722 if (RT_SUCCESS(rc)) {
2723 /*
2724 * Success, advance position and buffer.
2725 */
2726 uint32_t cbActual = pReq->Parms.cb32Write.u.value32;
2727 AssertStmt(cbActual <= cbChunk, cbActual = cbChunk);
2728
2729 vbsf_reg_write_sync_page_cache(mapping, offFile, cbActual, NULL /*pbSrcBuf*/, papPages, offPage0, cPages);
2730 vbsf_iter_unlock_pages(iter, papPages, cPages, false /*fSetDirty*/);
2731
2732 cbRet += cbActual;
2733 cbToWrite -= cbActual;
2734
2735 offFile += cbActual;
2736 if (fAppend && (g_fSfFeatures & SHFL_FEATURE_WRITE_UPDATES_OFFSET))
2737 offFile = pReq->Parms.off64Write.u.value64;
2738 kio->ki_pos = offFile;
2739 if (offFile > i_size_read(inode))
2740 i_size_write(inode, offFile);
2741
2742 sf_i->force_restat = 1; /* mtime (and size) may have changed */
2743
2744 /*
2745 * Are we done already?
2746 */
2747 if (!cbToWrite)
2748 break;
2749 if (cbActual < cbChunk) { /* We ASSUME end-of-file here. */
2750 if (vbsf_iter_rewind(iter, &Stash, cbChunk - cbActual, cbActual))
2751 iov_iter_truncate(iter, 0);
2752 break;
2753 }
2754 } else {
2755 /*
2756 * Try rewind the iter structure.
2757 */
2758 bool fRewindOkay;
2759 vbsf_iter_unlock_pages(iter, papPages, cPages, false /*fSetDirty*/);
2760 fRewindOkay = vbsf_iter_rewind(iter, &Stash, cbChunk, cbChunk);
2761 if (rc == VERR_NO_MEMORY && cMaxPages > 4 && fRewindOkay) {
2762 /*
2763 * The host probably doesn't have enough heap to handle the
2764 * request, reduce the page count and retry.
2765 */
2766 cMaxPages /= 4;
2767 Assert(cMaxPages > 0);
2768 } else {
2769 /*
2770 * If we've successfully written stuff, return it rather than
2771 * the error. (Not sure if this is such a great idea...)
2772 */
2773 if (cbRet <= 0)
2774 cbRet = -EPROTO;
2775 break;
2776 }
2777 }
2778 } while (cbToWrite > 0);
2779
2780 vbsf_iter_cleanup_stash(iter, &Stash);
2781 }
2782 else
2783 cbRet = -ENOMEM;
2784 if (papPagesFree)
2785 kfree(papPages);
2786 if (pReq)
2787 VbglR0PhysHeapFree(pReq);
2788 SFLOGFLOW(("vbsf_reg_write_iter_locking: returns %#zx (%zd)\n", cbRet, cbRet));
2789 return cbRet;
2790}
2791
2792
2793/**
2794 * Write from I/O vector iterator.
2795 *
2796 * @returns Number of bytes written on success, negative errno on error.
2797 * @param kio The kernel I/O control block (or something like that).
2798 * @param iter The I/O vector iterator describing the buffer.
2799 */
2800# if RTLNX_VER_MIN(3,16,0)
2801static ssize_t vbsf_reg_write_iter(struct kiocb *kio, struct iov_iter *iter)
2802# else
2803static ssize_t vbsf_reg_aio_write(struct kiocb *kio, const struct iovec *iov, unsigned long cSegs, loff_t offFile)
2804# endif
2805{
2806# if RTLNX_VER_MAX(3,16,0)
2807 struct vbsf_iov_iter fake_iter = VBSF_IOV_ITER_INITIALIZER(cSegs, iov, 1 /*write*/);
2808 struct vbsf_iov_iter *iter = &fake_iter;
2809# endif
2810 size_t cbToWrite = iov_iter_count(iter);
2811 struct inode *inode = VBSF_GET_F_DENTRY(kio->ki_filp)->d_inode;
2812 struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(inode);
2813 struct address_space *mapping = inode->i_mapping;
2814
2815 struct vbsf_reg_info *sf_r = kio->ki_filp->private_data;
2816 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
2817# if RTLNX_VER_MIN(3,16,0)
2818 loff_t offFile = kio->ki_pos;
2819# endif
2820# if RTLNX_VER_MIN(4,1,0)
2821 bool const fAppend = RT_BOOL(kio->ki_flags & IOCB_APPEND);
2822# else
2823 bool const fAppend = RT_BOOL(kio->ki_filp->f_flags & O_APPEND);
2824# endif
2825
2826
2827 SFLOGFLOW(("vbsf_reg_write_iter: inode=%p file=%p size=%#zx off=%#llx type=%#x\n",
2828 inode, kio->ki_filp, cbToWrite, offFile, iter->type));
2829 AssertReturn(S_ISREG(inode->i_mode), -EINVAL);
2830
2831 /*
2832 * Enforce APPEND flag (more later).
2833 */
2834 if (fAppend)
2835 kio->ki_pos = offFile = i_size_read(inode);
2836
2837 /*
2838 * Do we have anything at all to do here?
2839 */
2840 if (!cbToWrite)
2841 return 0;
2842
2843 /** @todo Implement the read-write caching mode. */
2844
2845 /*
2846 * Now now we reject async I/O requests.
2847 */
2848 if (!is_sync_kiocb(kio)) {
2849 SFLOGFLOW(("vbsf_reg_write_iter: async I/O not yet supported\n")); /** @todo extend FsPerf with AIO tests. */
2850 return -EOPNOTSUPP;
2851 }
2852
2853 /*
2854 * If there are active writable mappings, coordinate with any
2855 * pending writes via those.
2856 */
2857 if ( mapping
2858 && mapping->nrpages > 0
2859 && mapping_writably_mapped(mapping)) {
2860# if RTLNX_VER_MIN(2,6,32)
2861 int err = filemap_fdatawait_range(mapping, offFile, offFile + cbToWrite - 1);
2862 if (err)
2863 return err;
2864# else
2865 /** @todo ... */
2866# endif
2867 }
2868
2869 /*
2870 * For small requests, try use an embedded buffer provided we get a heap block
2871 * that does not cross page boundraries (see host code).
2872 */
2873 if (cbToWrite <= PAGE_SIZE / 4 * 3 - RT_UOFFSETOF(VBOXSFWRITEEMBEDDEDREQ, abData[0]) /* see allocator */) {
2874 uint32_t const cbReq = RT_UOFFSETOF(VBOXSFWRITEEMBEDDEDREQ, abData[0]) + cbToWrite;
2875 VBOXSFWRITEEMBEDDEDREQ *pReq = (VBOXSFWRITEEMBEDDEDREQ *)VbglR0PhysHeapAlloc(cbReq);
2876 if (pReq) {
2877 if ((PAGE_SIZE - ((uintptr_t)pReq & PAGE_OFFSET_MASK)) >= cbReq) {
2878 ssize_t cbRet;
2879 if (copy_from_iter(pReq->abData, cbToWrite, iter) == cbToWrite) {
2880 int vrc = VbglR0SfHostReqWriteEmbedded(pSuperInfo->map.root, pReq, sf_r->Handle.hHost,
2881 offFile, (uint32_t)cbToWrite);
2882 sf_i->ModificationTimeAtOurLastWrite = sf_i->ModificationTime;
2883 if (RT_SUCCESS(vrc)) {
2884 cbRet = pReq->Parms.cb32Write.u.value32;
2885 AssertStmt(cbRet <= (ssize_t)cbToWrite, cbRet = cbToWrite);
2886 vbsf_reg_write_sync_page_cache(mapping, offFile, (uint32_t)cbRet, pReq->abData,
2887 NULL /*papSrcPages*/, 0 /*offSrcPage0*/, 0 /*cSrcPages*/);
2888
2889 offFile += cbRet;
2890 if (fAppend && (g_fSfFeatures & SHFL_FEATURE_WRITE_UPDATES_OFFSET))
2891 offFile = pReq->Parms.off64Write.u.value64;
2892 kio->ki_pos = offFile;
2893 if (offFile > i_size_read(inode))
2894 i_size_write(inode, offFile);
2895
2896# if RTLNX_VER_MIN(4,11,0)
2897 if ((size_t)cbRet < cbToWrite)
2898 iov_iter_revert(iter, cbToWrite - cbRet);
2899# endif
2900 } else
2901 cbRet = -EPROTO;
2902 sf_i->force_restat = 1; /* mtime (and size) may have changed */
2903 } else
2904 cbRet = -EFAULT;
2905 VbglR0PhysHeapFree(pReq);
2906 SFLOGFLOW(("vbsf_reg_write_iter: returns %#zx (%zd)\n", cbRet, cbRet));
2907 return cbRet;
2908 }
2909 VbglR0PhysHeapFree(pReq);
2910 }
2911 }
2912
2913 /*
2914 * Otherwise do the page locking thing.
2915 */
2916 return vbsf_reg_write_iter_locking(kio, iter, cbToWrite, offFile, pSuperInfo, sf_r, inode, sf_i, mapping, fAppend);
2917}
2918
2919#endif /* >= 2.6.19 */
2920
2921/**
2922 * Used by vbsf_reg_open() and vbsf_inode_atomic_open() to
2923 *
2924 * @returns shared folders create flags.
2925 * @param fLnxOpen The linux O_XXX flags to convert.
2926 * @param pfHandle Pointer to vbsf_handle::fFlags.
2927 * @param pszCaller Caller, for logging purposes.
2928 */
2929uint32_t vbsf_linux_oflags_to_vbox(unsigned fLnxOpen, uint32_t *pfHandle, const char *pszCaller)
2930{
2931 uint32_t fVBoxFlags = SHFL_CF_ACCESS_DENYNONE;
2932
2933 /*
2934 * Disposition.
2935 */
2936 if (fLnxOpen & O_CREAT) {
2937 Log(("%s: O_CREAT set\n", pszCaller));
2938 fVBoxFlags |= SHFL_CF_ACT_CREATE_IF_NEW;
2939 if (fLnxOpen & O_EXCL) {
2940 Log(("%s: O_EXCL set\n", pszCaller));
2941 fVBoxFlags |= SHFL_CF_ACT_FAIL_IF_EXISTS;
2942 } else if (fLnxOpen & O_TRUNC) {
2943 Log(("%s: O_TRUNC set\n", pszCaller));
2944 fVBoxFlags |= SHFL_CF_ACT_OVERWRITE_IF_EXISTS;
2945 } else
2946 fVBoxFlags |= SHFL_CF_ACT_OPEN_IF_EXISTS;
2947 } else {
2948 fVBoxFlags |= SHFL_CF_ACT_FAIL_IF_NEW;
2949 if (fLnxOpen & O_TRUNC) {
2950 Log(("%s: O_TRUNC set\n", pszCaller));
2951 fVBoxFlags |= SHFL_CF_ACT_OVERWRITE_IF_EXISTS;
2952 }
2953 }
2954
2955 /*
2956 * Access.
2957 */
2958 switch (fLnxOpen & O_ACCMODE) {
2959 case O_RDONLY:
2960 fVBoxFlags |= SHFL_CF_ACCESS_READ;
2961 *pfHandle |= VBSF_HANDLE_F_READ;
2962 break;
2963
2964 case O_WRONLY:
2965 fVBoxFlags |= SHFL_CF_ACCESS_WRITE;
2966 *pfHandle |= VBSF_HANDLE_F_WRITE;
2967 break;
2968
2969 case O_RDWR:
2970 fVBoxFlags |= SHFL_CF_ACCESS_READWRITE;
2971 *pfHandle |= VBSF_HANDLE_F_READ | VBSF_HANDLE_F_WRITE;
2972 break;
2973
2974 default:
2975 BUG();
2976 }
2977
2978 if (fLnxOpen & O_APPEND) {
2979 Log(("%s: O_APPEND set\n", pszCaller));
2980 fVBoxFlags |= SHFL_CF_ACCESS_APPEND;
2981 *pfHandle |= VBSF_HANDLE_F_APPEND;
2982 }
2983
2984 /*
2985 * Only directories?
2986 */
2987 if (fLnxOpen & O_DIRECTORY) {
2988 Log(("%s: O_DIRECTORY set\n", pszCaller));
2989 fVBoxFlags |= SHFL_CF_DIRECTORY;
2990 }
2991
2992 return fVBoxFlags;
2993}
2994
2995
2996/**
2997 * Open a regular file.
2998 *
2999 * @param inode the inode
3000 * @param file the file
3001 * @returns 0 on success, Linux error code otherwise
3002 */
3003static int vbsf_reg_open(struct inode *inode, struct file *file)
3004{
3005 int rc, rc_linux = 0;
3006 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
3007 struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(inode);
3008 struct dentry *dentry = VBSF_GET_F_DENTRY(file);
3009 struct vbsf_reg_info *sf_r;
3010 VBOXSFCREATEREQ *pReq;
3011
3012 SFLOGFLOW(("vbsf_reg_open: inode=%p file=%p flags=%#x %s\n", inode, file, file->f_flags, sf_i ? sf_i->path->String.ach : NULL));
3013 Assert(pSuperInfo);
3014 Assert(sf_i);
3015
3016 sf_r = kmalloc(sizeof(*sf_r), GFP_KERNEL);
3017 if (!sf_r) {
3018 LogRelFunc(("could not allocate reg info\n"));
3019 return -ENOMEM;
3020 }
3021
3022 RTListInit(&sf_r->Handle.Entry);
3023 sf_r->Handle.cRefs = 1;
3024 sf_r->Handle.fFlags = VBSF_HANDLE_F_FILE | VBSF_HANDLE_F_MAGIC;
3025 sf_r->Handle.hHost = SHFL_HANDLE_NIL;
3026
3027 /* Already open? */
3028 if (sf_i->handle != SHFL_HANDLE_NIL) {
3029 /*
3030 * This inode was created with vbsf_create_worker(). Check the CreateFlags:
3031 * O_CREAT, O_TRUNC: inherent true (file was just created). Not sure
3032 * about the access flags (SHFL_CF_ACCESS_*).
3033 */
3034 sf_i->force_restat = 1;
3035 sf_r->Handle.hHost = sf_i->handle;
3036 sf_i->handle = SHFL_HANDLE_NIL;
3037 file->private_data = sf_r;
3038
3039 sf_r->Handle.fFlags |= VBSF_HANDLE_F_READ | VBSF_HANDLE_F_WRITE; /** @todo fix */
3040 vbsf_handle_append(sf_i, &sf_r->Handle);
3041 SFLOGFLOW(("vbsf_reg_open: returns 0 (#1) - sf_i=%p hHost=%#llx\n", sf_i, sf_r->Handle.hHost));
3042 return 0;
3043 }
3044
3045 pReq = (VBOXSFCREATEREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq) + sf_i->path->u16Size);
3046 if (!pReq) {
3047 kfree(sf_r);
3048 LogRelFunc(("Failed to allocate a VBOXSFCREATEREQ buffer!\n"));
3049 return -ENOMEM;
3050 }
3051 memcpy(&pReq->StrPath, sf_i->path, SHFLSTRING_HEADER_SIZE + sf_i->path->u16Size);
3052 RT_ZERO(pReq->CreateParms);
3053 pReq->CreateParms.Handle = SHFL_HANDLE_NIL;
3054
3055 /* We check the value of pReq->CreateParms.Handle afterwards to
3056 * find out if the call succeeded or failed, as the API does not seem
3057 * to cleanly distinguish error and informational messages.
3058 *
3059 * Furthermore, we must set pReq->CreateParms.Handle to SHFL_HANDLE_NIL
3060 * to make the shared folders host service use our fMode parameter */
3061
3062 /* We ignore O_EXCL, as the Linux kernel seems to call create
3063 beforehand itself, so O_EXCL should always fail. */
3064 pReq->CreateParms.CreateFlags = vbsf_linux_oflags_to_vbox(file->f_flags & ~O_EXCL, &sf_r->Handle.fFlags, __FUNCTION__);
3065 pReq->CreateParms.Info.Attr.fMode = inode->i_mode;
3066 LogFunc(("vbsf_reg_open: calling VbglR0SfHostReqCreate, file %s, flags=%#x, %#x\n",
3067 sf_i->path->String.utf8, file->f_flags, pReq->CreateParms.CreateFlags));
3068 rc = VbglR0SfHostReqCreate(pSuperInfo->map.root, pReq);
3069 if (RT_FAILURE(rc)) {
3070 LogFunc(("VbglR0SfHostReqCreate failed flags=%d,%#x rc=%Rrc\n", file->f_flags, pReq->CreateParms.CreateFlags, rc));
3071 kfree(sf_r);
3072 VbglR0PhysHeapFree(pReq);
3073 return -RTErrConvertToErrno(rc);
3074 }
3075
3076 if (pReq->CreateParms.Handle != SHFL_HANDLE_NIL) {
3077 vbsf_dentry_chain_increase_ttl(dentry);
3078 vbsf_update_inode(inode, sf_i, &pReq->CreateParms.Info, pSuperInfo, false /*fInodeLocked*/, 0 /*fSetAttrs*/);
3079 rc_linux = 0;
3080 } else {
3081 switch (pReq->CreateParms.Result) {
3082 case SHFL_PATH_NOT_FOUND:
3083 vbsf_dentry_invalidate_ttl(dentry);
3084 rc_linux = -ENOENT;
3085 break;
3086 case SHFL_FILE_NOT_FOUND:
3087 vbsf_dentry_invalidate_ttl(dentry);
3088 /** @todo sf_dentry_increase_parent_ttl(file->f_dentry); if we can trust it. */
3089 rc_linux = -ENOENT;
3090 break;
3091 case SHFL_FILE_EXISTS:
3092 vbsf_dentry_chain_increase_ttl(dentry);
3093 vbsf_update_inode(inode, sf_i, &pReq->CreateParms.Info, pSuperInfo, false /*fInodeLocked*/, 0 /*fSetAttrs*/);
3094 rc_linux = -EEXIST;
3095 break;
3096 default:
3097 vbsf_dentry_chain_increase_parent_ttl(dentry);
3098 rc_linux = 0;
3099 break;
3100 }
3101 }
3102
3103 sf_r->Handle.hHost = pReq->CreateParms.Handle;
3104 file->private_data = sf_r;
3105 vbsf_handle_append(sf_i, &sf_r->Handle);
3106 VbglR0PhysHeapFree(pReq);
3107 SFLOGFLOW(("vbsf_reg_open: returns 0 (#2) - sf_i=%p hHost=%#llx\n", sf_i, sf_r->Handle.hHost));
3108 return rc_linux;
3109}
3110
3111
3112/**
3113 * Close a regular file.
3114 *
3115 * @param inode the inode
3116 * @param file the file
3117 * @returns 0 on success, Linux error code otherwise
3118 */
3119static int vbsf_reg_release(struct inode *inode, struct file *file)
3120{
3121 struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(inode);
3122 struct vbsf_reg_info *sf_r = file->private_data;
3123
3124 SFLOGFLOW(("vbsf_reg_release: inode=%p file=%p\n", inode, file));
3125 if (sf_r) {
3126 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
3127 struct address_space *mapping = inode->i_mapping;
3128 Assert(pSuperInfo);
3129
3130 /* If we're closing the last handle for this inode, make sure the flush
3131 the mapping or we'll end up in vbsf_writepage without a handle. */
3132 if ( mapping
3133 && mapping->nrpages > 0
3134 /** @todo && last writable handle */ ) {
3135#if RTLNX_VER_MIN(2,4,25)
3136 if (filemap_fdatawrite(mapping) != -EIO)
3137#else
3138 if ( filemap_fdatasync(mapping) == 0
3139 && fsync_inode_data_buffers(inode) == 0)
3140#endif
3141 filemap_fdatawait(inode->i_mapping);
3142 }
3143
3144 /* Release sf_r, closing the handle if we're the last user. */
3145 file->private_data = NULL;
3146 vbsf_handle_release(&sf_r->Handle, pSuperInfo, "vbsf_reg_release");
3147
3148 sf_i->handle = SHFL_HANDLE_NIL;
3149 }
3150 return 0;
3151}
3152
3153
3154/**
3155 * Wrapper around generic/default seek function that ensures that we've got
3156 * the up-to-date file size when doing anything relative to EOF.
3157 *
3158 * The issue is that the host may extend the file while we weren't looking and
3159 * if the caller wishes to append data, it may end up overwriting existing data
3160 * if we operate with a stale size. So, we always retrieve the file size on EOF
3161 * relative seeks.
3162 */
3163static loff_t vbsf_reg_llseek(struct file *file, loff_t off, int whence)
3164{
3165 SFLOGFLOW(("vbsf_reg_llseek: file=%p off=%lld whence=%d\n", file, off, whence));
3166
3167 switch (whence) {
3168#ifdef SEEK_HOLE
3169 case SEEK_HOLE:
3170 case SEEK_DATA:
3171#endif
3172 case SEEK_END: {
3173 struct vbsf_reg_info *sf_r = file->private_data;
3174 int rc = vbsf_inode_revalidate_with_handle(VBSF_GET_F_DENTRY(file), sf_r->Handle.hHost,
3175 true /*fForce*/, false /*fInodeLocked*/);
3176 if (rc == 0)
3177 break;
3178 return rc;
3179 }
3180 }
3181
3182#if RTLNX_VER_MIN(2,4,8)
3183 return generic_file_llseek(file, off, whence);
3184#else
3185 return default_llseek(file, off, whence);
3186#endif
3187}
3188
3189
3190/**
3191 * Flush region of file - chiefly mmap/msync.
3192 *
3193 * We cannot use the noop_fsync / simple_sync_file here as that means
3194 * msync(,,MS_SYNC) will return before the data hits the host, thereby
3195 * causing coherency issues with O_DIRECT access to the same file as
3196 * well as any host interaction with the file.
3197 */
3198#if RTLNX_VER_MIN(3,1,0) \
3199 || (defined(CONFIG_SUSE_KERNEL) && RTLNX_VER_MIN(3,0,101) /** @todo figure when exactly */)
3200static int vbsf_reg_fsync(struct file *file, loff_t start, loff_t end, int datasync)
3201{
3202# if RTLNX_VER_MIN(3,16,0)
3203 return __generic_file_fsync(file, start, end, datasync);
3204# else
3205 return generic_file_fsync(file, start, end, datasync);
3206# endif
3207}
3208#elif RTLNX_VER_MIN(2,6,35)
3209static int vbsf_reg_fsync(struct file *file, int datasync)
3210{
3211 return generic_file_fsync(file, datasync);
3212}
3213#else /* < 2.6.35 */
3214static int vbsf_reg_fsync(struct file *file, struct dentry *dentry, int datasync)
3215{
3216# if RTLNX_VER_MIN(2,6,31)
3217 return simple_fsync(file, dentry, datasync);
3218# else
3219 int rc;
3220 struct inode *inode = dentry->d_inode;
3221 AssertReturn(inode, -EINVAL);
3222
3223 /** @todo What about file_fsync()? (<= 2.5.11) */
3224
3225# if RTLNX_VER_MIN(2,5,12)
3226 rc = sync_mapping_buffers(inode->i_mapping);
3227 if ( rc == 0
3228 && (inode->i_state & I_DIRTY)
3229 && ((inode->i_state & I_DIRTY_DATASYNC) || !datasync)
3230 ) {
3231 struct writeback_control wbc = {
3232 .sync_mode = WB_SYNC_ALL,
3233 .nr_to_write = 0
3234 };
3235 rc = sync_inode(inode, &wbc);
3236 }
3237# else /* < 2.5.12 */
3238 /** @todo
3239 * Somethings is buggy here or in the 2.4.21-27.EL kernel I'm testing on.
3240 *
3241 * In theory we shouldn't need to do anything here, since msync will call
3242 * writepage() on each dirty page and we write them out synchronously. So, the
3243 * problem is elsewhere... Doesn't happen all the time either. Sigh.
3244 */
3245 rc = fsync_inode_buffers(inode);
3246# if RTLNX_VER_MIN(2,4,10)
3247 if (rc == 0 && datasync)
3248 rc = fsync_inode_data_buffers(inode);
3249# endif
3250
3251# endif /* < 2.5.12 */
3252 return rc;
3253# endif
3254}
3255#endif /* < 2.6.35 */
3256
3257
3258#if RTLNX_VER_MIN(4,5,0)
3259/**
3260 * Copy a datablock from one file to another on the host side.
3261 */
3262static ssize_t vbsf_reg_copy_file_range(struct file *pFileSrc, loff_t offSrc, struct file *pFileDst, loff_t offDst,
3263 size_t cbRange, unsigned int fFlags)
3264{
3265 ssize_t cbRet;
3266 if (g_uSfLastFunction >= SHFL_FN_COPY_FILE_PART) {
3267 struct inode *pInodeSrc = pFileSrc->f_inode;
3268 struct vbsf_inode_info *pInodeInfoSrc = VBSF_GET_INODE_INFO(pInodeSrc);
3269 struct vbsf_super_info *pSuperInfoSrc = VBSF_GET_SUPER_INFO(pInodeSrc->i_sb);
3270 struct vbsf_reg_info *pFileInfoSrc = (struct vbsf_reg_info *)pFileSrc->private_data;
3271 struct inode *pInodeDst = pInodeSrc;
3272 struct vbsf_inode_info *pInodeInfoDst = VBSF_GET_INODE_INFO(pInodeDst);
3273 struct vbsf_super_info *pSuperInfoDst = VBSF_GET_SUPER_INFO(pInodeDst->i_sb);
3274 struct vbsf_reg_info *pFileInfoDst = (struct vbsf_reg_info *)pFileDst->private_data;
3275 VBOXSFCOPYFILEPARTREQ *pReq;
3276
3277 /*
3278 * Some extra validation.
3279 */
3280 AssertPtrReturn(pInodeInfoSrc, -EOPNOTSUPP);
3281 Assert(pInodeInfoSrc->u32Magic == SF_INODE_INFO_MAGIC);
3282 AssertPtrReturn(pInodeInfoDst, -EOPNOTSUPP);
3283 Assert(pInodeInfoDst->u32Magic == SF_INODE_INFO_MAGIC);
3284
3285# if RTLNX_VER_MAX(4,11,0)
3286 if (!S_ISREG(pInodeSrc->i_mode) || !S_ISREG(pInodeDst->i_mode))
3287 return S_ISDIR(pInodeSrc->i_mode) || S_ISDIR(pInodeDst->i_mode) ? -EISDIR : -EINVAL;
3288# endif
3289
3290 /*
3291 * Allocate the request and issue it.
3292 */
3293 pReq = (VBOXSFCOPYFILEPARTREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq));
3294 if (pReq) {
3295 int vrc = VbglR0SfHostReqCopyFilePart(pSuperInfoSrc->map.root, pFileInfoSrc->Handle.hHost, offSrc,
3296 pSuperInfoDst->map.root, pFileInfoDst->Handle.hHost, offDst,
3297 cbRange, 0 /*fFlags*/, pReq);
3298 if (RT_SUCCESS(vrc))
3299 cbRet = pReq->Parms.cb64ToCopy.u.value64;
3300 else if (vrc == VERR_NOT_IMPLEMENTED)
3301 cbRet = -EOPNOTSUPP;
3302 else
3303 cbRet = -RTErrConvertToErrno(vrc);
3304
3305 VbglR0PhysHeapFree(pReq);
3306 } else
3307 cbRet = -ENOMEM;
3308 } else {
3309 cbRet = -EOPNOTSUPP;
3310 }
3311 SFLOGFLOW(("vbsf_reg_copy_file_range: returns %zd\n", cbRet));
3312 return cbRet;
3313}
3314#endif /* > 4.5 */
3315
3316
3317#ifdef SFLOG_ENABLED
3318/*
3319 * This is just for logging page faults and such.
3320 */
3321
3322/** Pointer to the ops generic_file_mmap returns the first time it's called. */
3323static struct vm_operations_struct const *g_pGenericFileVmOps = NULL;
3324/** Merge of g_LoggingVmOpsTemplate and g_pGenericFileVmOps. */
3325static struct vm_operations_struct g_LoggingVmOps;
3326
3327
3328/* Generic page fault callback: */
3329# if RTLNX_VER_MIN(4,11,0)
3330static vm_fault_t vbsf_vmlog_fault(struct vm_fault *vmf)
3331{
3332 vm_fault_t rc;
3333 SFLOGFLOW(("vbsf_vmlog_fault: vmf=%p flags=%#x addr=%p\n", vmf, vmf->flags, vmf->address));
3334 rc = g_pGenericFileVmOps->fault(vmf);
3335 SFLOGFLOW(("vbsf_vmlog_fault: returns %d\n", rc));
3336 return rc;
3337}
3338# elif RTLNX_VER_MIN(2,6,23)
3339static int vbsf_vmlog_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
3340{
3341 int rc;
3342# if RTLNX_VER_MIN(4,10,0)
3343 SFLOGFLOW(("vbsf_vmlog_fault: vma=%p vmf=%p flags=%#x addr=%p\n", vma, vmf, vmf->flags, vmf->address));
3344# else
3345 SFLOGFLOW(("vbsf_vmlog_fault: vma=%p vmf=%p flags=%#x addr=%p\n", vma, vmf, vmf->flags, vmf->virtual_address));
3346# endif
3347 rc = g_pGenericFileVmOps->fault(vma, vmf);
3348 SFLOGFLOW(("vbsf_vmlog_fault: returns %d\n", rc));
3349 return rc;
3350}
3351# endif
3352
3353
3354/* Special/generic page fault handler: */
3355# if RTLNX_VER_MIN(2,6,26)
3356# elif RTLNX_VER_MIN(2,6,1)
3357static struct page *vbsf_vmlog_nopage(struct vm_area_struct *vma, unsigned long address, int *type)
3358{
3359 struct page *page;
3360 SFLOGFLOW(("vbsf_vmlog_nopage: vma=%p address=%p type=%p:{%#x}\n", vma, address, type, type ? *type : 0));
3361 page = g_pGenericFileVmOps->nopage(vma, address, type);
3362 SFLOGFLOW(("vbsf_vmlog_nopage: returns %p\n", page));
3363 return page;
3364}
3365# else
3366static struct page *vbsf_vmlog_nopage(struct vm_area_struct *vma, unsigned long address, int write_access_or_unused)
3367{
3368 struct page *page;
3369 SFLOGFLOW(("vbsf_vmlog_nopage: vma=%p address=%p wau=%d\n", vma, address, write_access_or_unused));
3370 page = g_pGenericFileVmOps->nopage(vma, address, write_access_or_unused);
3371 SFLOGFLOW(("vbsf_vmlog_nopage: returns %p\n", page));
3372 return page;
3373}
3374# endif /* < 2.6.26 */
3375
3376
3377/* Special page fault callback for making something writable: */
3378# if RTLNX_VER_MIN(4,11,0)
3379static vm_fault_t vbsf_vmlog_page_mkwrite(struct vm_fault *vmf)
3380{
3381 vm_fault_t rc;
3382 SFLOGFLOW(("vbsf_vmlog_page_mkwrite: vmf=%p flags=%#x addr=%p\n", vmf, vmf->flags, vmf->address));
3383 rc = g_pGenericFileVmOps->page_mkwrite(vmf);
3384 SFLOGFLOW(("vbsf_vmlog_page_mkwrite: returns %d\n", rc));
3385 return rc;
3386}
3387# elif RTLNX_VER_MIN(2,6,30)
3388static int vbsf_vmlog_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3389{
3390 int rc;
3391# if RTLNX_VER_MIN(4,10,0)
3392 SFLOGFLOW(("vbsf_vmlog_page_mkwrite: vma=%p vmf=%p flags=%#x addr=%p\n", vma, vmf, vmf->flags, vmf->address));
3393# else
3394 SFLOGFLOW(("vbsf_vmlog_page_mkwrite: vma=%p vmf=%p flags=%#x addr=%p\n", vma, vmf, vmf->flags, vmf->virtual_address));
3395# endif
3396 rc = g_pGenericFileVmOps->page_mkwrite(vma, vmf);
3397 SFLOGFLOW(("vbsf_vmlog_page_mkwrite: returns %d\n", rc));
3398 return rc;
3399}
3400# elif RTLNX_VER_MIN(2,6,18)
3401static int vbsf_vmlog_page_mkwrite(struct vm_area_struct *vma, struct page *page)
3402{
3403 int rc;
3404 SFLOGFLOW(("vbsf_vmlog_page_mkwrite: vma=%p page=%p\n", vma, page));
3405 rc = g_pGenericFileVmOps->page_mkwrite(vma, page);
3406 SFLOGFLOW(("vbsf_vmlog_page_mkwrite: returns %d\n", rc));
3407 return rc;
3408}
3409# endif
3410
3411
3412/* Special page fault callback for mapping pages: */
3413# if RTLNX_VER_MIN(5,12,0)
3414static vm_fault_t vbsf_vmlog_map_pages(struct vm_fault *vmf, pgoff_t start, pgoff_t end)
3415{
3416 vm_fault_t rc;
3417 SFLOGFLOW(("vbsf_vmlog_map_pages: vmf=%p (flags=%#x addr=%p) start=%p end=%p\n", vmf, vmf->flags, vmf->address, start, end));
3418 rc = g_pGenericFileVmOps->map_pages(vmf, start, end);
3419 SFLOGFLOW(("vbsf_vmlog_map_pages: returns\n"));
3420 return rc;
3421}
3422# elif RTLNX_VER_MIN(4,10,0)
3423static void vbsf_vmlog_map_pages(struct vm_fault *vmf, pgoff_t start, pgoff_t end)
3424{
3425 SFLOGFLOW(("vbsf_vmlog_map_pages: vmf=%p (flags=%#x addr=%p) start=%p end=%p\n", vmf, vmf->flags, vmf->address, start, end));
3426 g_pGenericFileVmOps->map_pages(vmf, start, end);
3427 SFLOGFLOW(("vbsf_vmlog_map_pages: returns\n"));
3428}
3429# elif RTLNX_VER_MIN(4,8,0)
3430static void vbsf_vmlog_map_pages(struct fault_env *fenv, pgoff_t start, pgoff_t end)
3431{
3432 SFLOGFLOW(("vbsf_vmlog_map_pages: fenv=%p (flags=%#x addr=%p) start=%p end=%p\n", fenv, fenv->flags, fenv->address, start, end));
3433 g_pGenericFileVmOps->map_pages(fenv, start, end);
3434 SFLOGFLOW(("vbsf_vmlog_map_pages: returns\n"));
3435}
3436# elif RTLNX_VER_MIN(3,15,0)
3437static void vbsf_vmlog_map_pages(struct vm_area_struct *vma, struct vm_fault *vmf)
3438{
3439 SFLOGFLOW(("vbsf_vmlog_map_pages: vma=%p vmf=%p (flags=%#x addr=%p)\n", vma, vmf, vmf->flags, vmf->virtual_address));
3440 g_pGenericFileVmOps->map_pages(vma, vmf);
3441 SFLOGFLOW(("vbsf_vmlog_map_pages: returns\n"));
3442}
3443# endif
3444
3445
3446/** Overload template. */
3447static struct vm_operations_struct const g_LoggingVmOpsTemplate = {
3448# if RTLNX_VER_MIN(2,6,23)
3449 .fault = vbsf_vmlog_fault,
3450# endif
3451# if RTLNX_VER_MAX(2,6,26)
3452 .nopage = vbsf_vmlog_nopage,
3453# endif
3454# if RTLNX_VER_MIN(2,6,18)
3455 .page_mkwrite = vbsf_vmlog_page_mkwrite,
3456# endif
3457# if RTLNX_VER_MIN(3,15,0)
3458 .map_pages = vbsf_vmlog_map_pages,
3459# endif
3460};
3461
3462/** file_operations::mmap wrapper for logging purposes. */
3463extern int vbsf_reg_mmap(struct file *file, struct vm_area_struct *vma)
3464{
3465 int rc;
3466 SFLOGFLOW(("vbsf_reg_mmap: file=%p vma=%p\n", file, vma));
3467 rc = generic_file_mmap(file, vma);
3468 if (rc == 0) {
3469 /* Merge the ops and template the first time thru (there's a race here). */
3470 if (g_pGenericFileVmOps == NULL) {
3471 uintptr_t const *puSrc1 = (uintptr_t *)vma->vm_ops;
3472 uintptr_t const *puSrc2 = (uintptr_t *)&g_LoggingVmOpsTemplate;
3473 uintptr_t volatile *puDst = (uintptr_t *)&g_LoggingVmOps;
3474 size_t cbLeft = sizeof(g_LoggingVmOps) / sizeof(*puDst);
3475 while (cbLeft-- > 0) {
3476 *puDst = *puSrc2 && *puSrc1 ? *puSrc2 : *puSrc1;
3477 puSrc1++;
3478 puSrc2++;
3479 puDst++;
3480 }
3481 g_pGenericFileVmOps = vma->vm_ops;
3482 vma->vm_ops = &g_LoggingVmOps;
3483 } else if (g_pGenericFileVmOps == vma->vm_ops)
3484 vma->vm_ops = &g_LoggingVmOps;
3485 else
3486 SFLOGFLOW(("vbsf_reg_mmap: Warning: vm_ops=%p, expected %p!\n", vma->vm_ops, g_pGenericFileVmOps));
3487 }
3488 SFLOGFLOW(("vbsf_reg_mmap: returns %d\n", rc));
3489 return rc;
3490}
3491
3492#endif /* SFLOG_ENABLED */
3493
3494
3495/**
3496 * File operations for regular files.
3497 *
3498 * Note on splice_read/splice_write/sendfile:
3499 * - Splice was introduced in 2.6.17. The generic_file_splice_read/write
3500 * methods go thru the page cache, which is undesirable and is why we
3501 * need to cook our own versions of the code as long as we cannot track
3502 * host-side writes and correctly invalidate the guest page-cache.
3503 * - Sendfile reimplemented using splice in 2.6.23.
3504 * - The default_file_splice_read/write no-page-cache fallback functions,
3505 * were introduced in 2.6.31. The write one work in page units.
3506 * - Since linux 3.16 there is iter_file_splice_write that uses iter_write.
3507 * - Since linux 4.9 the generic_file_splice_read function started using
3508 * read_iter.
3509 */
3510struct file_operations vbsf_reg_fops = {
3511 .open = vbsf_reg_open,
3512#if RTLNX_VER_MAX(5,10,0) /* No regular .read/.write for 5.10, only .read_iter/.write_iter or in-kernel reads/writes fail. */
3513 .read = vbsf_reg_read,
3514 .write = vbsf_reg_write,
3515#endif
3516#if RTLNX_VER_MIN(3,16,0)
3517 .read_iter = vbsf_reg_read_iter,
3518 .write_iter = vbsf_reg_write_iter,
3519#elif RTLNX_VER_MIN(2,6,19)
3520 .aio_read = vbsf_reg_aio_read,
3521 .aio_write = vbsf_reg_aio_write,
3522#endif
3523 .release = vbsf_reg_release,
3524#ifdef SFLOG_ENABLED
3525 .mmap = vbsf_reg_mmap,
3526#else
3527 .mmap = generic_file_mmap,
3528#endif
3529#if RTLNX_VER_RANGE(2,6,17, 2,6,31)
3530 .splice_read = vbsf_splice_read,
3531#endif
3532#if RTLNX_VER_MIN(3,16,0)
3533 .splice_write = iter_file_splice_write,
3534#elif RTLNX_VER_MIN(2,6,17)
3535 .splice_write = vbsf_splice_write,
3536#endif
3537#if RTLNX_VER_RANGE(2,5,30, 2,6,23)
3538 .sendfile = vbsf_reg_sendfile,
3539#endif
3540 .llseek = vbsf_reg_llseek,
3541 .fsync = vbsf_reg_fsync,
3542#if RTLNX_VER_MIN(4,5,0)
3543 .copy_file_range = vbsf_reg_copy_file_range,
3544#endif
3545};
3546
3547
3548/**
3549 * Inodes operations for regular files.
3550 */
3551struct inode_operations vbsf_reg_iops = {
3552#if RTLNX_VER_MIN(2,5,18)
3553 .getattr = vbsf_inode_getattr,
3554#else
3555 .revalidate = vbsf_inode_revalidate,
3556#endif
3557 .setattr = vbsf_inode_setattr,
3558};
3559
3560
3561
3562/*********************************************************************************************************************************
3563* Address Space Operations on Regular Files (for mmap, sendfile, direct I/O) *
3564*********************************************************************************************************************************/
3565
3566/**
3567 * Used to read the content of a page into the page cache.
3568 *
3569 * Needed for mmap and reads+writes when the file is mmapped in a
3570 * shared+writeable fashion.
3571 */
3572static int vbsf_readpage(struct file *file, struct page *page)
3573{
3574 struct inode *inode = VBSF_GET_F_DENTRY(file)->d_inode;
3575 int err;
3576
3577 SFLOGFLOW(("vbsf_readpage: inode=%p file=%p page=%p off=%#llx\n", inode, file, page, (uint64_t)page->index << PAGE_SHIFT));
3578 Assert(PageLocked(page));
3579
3580 if (PageUptodate(page)) {
3581 unlock_page(page);
3582 return 0;
3583 }
3584
3585 if (!is_bad_inode(inode)) {
3586 VBOXSFREADPGLSTREQ *pReq = (VBOXSFREADPGLSTREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq));
3587 if (pReq) {
3588 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
3589 struct vbsf_reg_info *sf_r = file->private_data;
3590 uint32_t cbRead;
3591 int vrc;
3592
3593 pReq->PgLst.offFirstPage = 0;
3594 pReq->PgLst.aPages[0] = page_to_phys(page);
3595 vrc = VbglR0SfHostReqReadPgLst(pSuperInfo->map.root,
3596 pReq,
3597 sf_r->Handle.hHost,
3598 (uint64_t)page->index << PAGE_SHIFT,
3599 PAGE_SIZE,
3600 1 /*cPages*/);
3601
3602 cbRead = pReq->Parms.cb32Read.u.value32;
3603 AssertStmt(cbRead <= PAGE_SIZE, cbRead = PAGE_SIZE);
3604 VbglR0PhysHeapFree(pReq);
3605
3606 if (RT_SUCCESS(vrc)) {
3607 if (cbRead == PAGE_SIZE) {
3608 /* likely */
3609 } else {
3610 uint8_t *pbMapped = (uint8_t *)kmap(page);
3611 RT_BZERO(&pbMapped[cbRead], PAGE_SIZE - cbRead);
3612 kunmap(page);
3613 /** @todo truncate the inode file size? */
3614 }
3615
3616 flush_dcache_page(page);
3617 SetPageUptodate(page);
3618 unlock_page(page);
3619 return 0;
3620 }
3621 err = -RTErrConvertToErrno(vrc);
3622 } else
3623 err = -ENOMEM;
3624 } else
3625 err = -EIO;
3626 SetPageError(page);
3627 unlock_page(page);
3628 return err;
3629}
3630
3631
3632/**
3633 * Used to write out the content of a dirty page cache page to the host file.
3634 *
3635 * Needed for mmap and writes when the file is mmapped in a shared+writeable
3636 * fashion.
3637 */
3638#if RTLNX_VER_MIN(2,5,52)
3639static int vbsf_writepage(struct page *page, struct writeback_control *wbc)
3640#else
3641static int vbsf_writepage(struct page *page)
3642#endif
3643{
3644 struct address_space *mapping = page->mapping;
3645 struct inode *inode = mapping->host;
3646 struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(inode);
3647 struct vbsf_handle *pHandle = vbsf_handle_find(sf_i, VBSF_HANDLE_F_WRITE, VBSF_HANDLE_F_APPEND);
3648 int err;
3649
3650 SFLOGFLOW(("vbsf_writepage: inode=%p page=%p off=%#llx pHandle=%p (%#llx)\n",
3651 inode, page, (uint64_t)page->index << PAGE_SHIFT, pHandle, pHandle ? pHandle->hHost : 0));
3652
3653 if (pHandle) {
3654 struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(inode->i_sb);
3655 VBOXSFWRITEPGLSTREQ *pReq = (VBOXSFWRITEPGLSTREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq));
3656 if (pReq) {
3657 uint64_t const cbFile = i_size_read(inode);
3658 uint64_t const offInFile = (uint64_t)page->index << PAGE_SHIFT;
3659 uint32_t const cbToWrite = page->index != (cbFile >> PAGE_SHIFT) ? PAGE_SIZE
3660 : (uint32_t)cbFile & (uint32_t)PAGE_OFFSET_MASK;
3661 int vrc;
3662
3663 pReq->PgLst.offFirstPage = 0;
3664 pReq->PgLst.aPages[0] = page_to_phys(page);
3665 vrc = VbglR0SfHostReqWritePgLst(pSuperInfo->map.root,
3666 pReq,
3667 pHandle->hHost,
3668 offInFile,
3669 cbToWrite,
3670 1 /*cPages*/);
3671 sf_i->ModificationTimeAtOurLastWrite = sf_i->ModificationTime;
3672 AssertMsgStmt(pReq->Parms.cb32Write.u.value32 == cbToWrite || RT_FAILURE(vrc), /* lazy bird */
3673 ("%#x vs %#x\n", pReq->Parms.cb32Write, cbToWrite),
3674 vrc = VERR_WRITE_ERROR);
3675 VbglR0PhysHeapFree(pReq);
3676
3677 if (RT_SUCCESS(vrc)) {
3678 /* Update the inode if we've extended the file. */
3679 /** @todo is this necessary given the cbToWrite calc above? */
3680 uint64_t const offEndOfWrite = offInFile + cbToWrite;
3681 if ( offEndOfWrite > cbFile
3682 && offEndOfWrite > i_size_read(inode))
3683 i_size_write(inode, offEndOfWrite);
3684
3685 /* Update and unlock the page. */
3686 if (PageError(page))
3687 ClearPageError(page);
3688 SetPageUptodate(page);
3689 unlock_page(page);
3690
3691 vbsf_handle_release(pHandle, pSuperInfo, "vbsf_writepage");
3692 return 0;
3693 }
3694
3695 /*
3696 * We failed.
3697 */
3698 err = -EIO;
3699 } else
3700 err = -ENOMEM;
3701 vbsf_handle_release(pHandle, pSuperInfo, "vbsf_writepage");
3702 } else {
3703 /** @todo we could re-open the file here and deal with this... */
3704 static uint64_t volatile s_cCalls = 0;
3705 if (s_cCalls++ < 16)
3706 printk("vbsf_writepage: no writable handle for %s..\n", sf_i->path->String.ach);
3707 err = -EIO;
3708 }
3709 SetPageError(page);
3710 unlock_page(page);
3711 return err;
3712}
3713
3714
3715#if RTLNX_VER_MIN(2,6,24)
3716/**
3717 * Called when writing thru the page cache (which we shouldn't be doing).
3718 */
3719int vbsf_write_begin(struct file *file, struct address_space *mapping, loff_t pos,
3720 unsigned len, unsigned flags, struct page **pagep, void **fsdata)
3721{
3722 /** @todo r=bird: We shouldn't ever get here, should we? Because we don't use
3723 * the page cache for any writes AFAIK. We could just as well use
3724 * simple_write_begin & simple_write_end here if we think we really
3725 * need to have non-NULL function pointers in the table... */
3726 static uint64_t volatile s_cCalls = 0;
3727 if (s_cCalls++ < 16) {
3728 printk("vboxsf: Unexpected call to vbsf_write_begin(pos=%#llx len=%#x flags=%#x)! Please report.\n",
3729 (unsigned long long)pos, len, flags);
3730 RTLogBackdoorPrintf("vboxsf: Unexpected call to vbsf_write_begin(pos=%#llx len=%#x flags=%#x)! Please report.\n",
3731 (unsigned long long)pos, len, flags);
3732# ifdef WARN_ON
3733 WARN_ON(1);
3734# endif
3735 }
3736 return simple_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
3737}
3738#endif /* KERNEL_VERSION >= 2.6.24 */
3739
3740
3741#if RTLNX_VER_MIN(2,4,10)
3742
3743# ifdef VBOX_UEK
3744# undef iov_iter /* HACK ALERT! Don't put anything needing vbsf_iov_iter after this fun! */
3745# endif
3746
3747/**
3748 * This is needed to make open accept O_DIRECT as well as dealing with direct
3749 * I/O requests if we don't intercept them earlier.
3750 */
3751# if RTLNX_VER_MIN(4, 7, 0) \
3752 || (defined(CONFIG_SUSE_KERNEL) && RTLNX_VER_RANGE(4,4,73, 4,4,74) /** @todo Figure out when exactly. */) \
3753 || (defined(CONFIG_SUSE_KERNEL) && RTLNX_VER_RANGE(4,4,75, 4,4,90) /** @todo Figure out when exactly. */) \
3754 || (defined(CONFIG_SUSE_KERNEL) && RTLNX_VER_RANGE(4,4,92, 4,5,0) /** @todo Figure out when exactly. */)
3755static ssize_t vbsf_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
3756# elif RTLNX_VER_MIN(4, 1, 0)
3757static ssize_t vbsf_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
3758# elif RTLNX_VER_MIN(3, 16, 0) || defined(VBOX_UEK)
3759static ssize_t vbsf_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
3760# elif RTLNX_VER_MIN(2, 6, 6)
3761static ssize_t vbsf_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs)
3762# elif RTLNX_VER_MIN(2, 5, 55)
3763static int vbsf_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs)
3764# elif RTLNX_VER_MIN(2, 5, 41)
3765static int vbsf_direct_IO(int rw, struct file *file, const struct iovec *iov, loff_t offset, unsigned long nr_segs)
3766# elif RTLNX_VER_MIN(2, 5, 35)
3767static int vbsf_direct_IO(int rw, struct inode *inode, const struct iovec *iov, loff_t offset, unsigned long nr_segs)
3768# elif RTLNX_VER_MIN(2, 5, 26)
3769static int vbsf_direct_IO(int rw, struct inode *inode, char *buf, loff_t offset, size_t count)
3770# elif LINUX_VERSION_CODE == KERNEL_VERSION(2, 4, 21) && defined(I_NEW) /* RHEL3 Frankenkernel. */
3771static int vbsf_direct_IO(int rw, struct file *file, struct kiobuf *buf, unsigned long whatever1, int whatever2)
3772# else
3773static int vbsf_direct_IO(int rw, struct inode *inode, struct kiobuf *buf, unsigned long whatever1, int whatever2)
3774# endif
3775{
3776 TRACE();
3777 return -EINVAL;
3778}
3779
3780#endif
3781
3782/**
3783 * Address space (for the page cache) operations for regular files.
3784 *
3785 * @todo the FsPerf touch/flush (mmap) test fails on 4.4.0 (ubuntu 16.04 lts).
3786 */
3787struct address_space_operations vbsf_reg_aops = {
3788 .readpage = vbsf_readpage,
3789 .writepage = vbsf_writepage,
3790 /** @todo Need .writepages if we want msync performance... */
3791#if RTLNX_VER_MIN(2,5,12)
3792 .set_page_dirty = __set_page_dirty_buffers,
3793#endif
3794#if RTLNX_VER_MIN(2,6,24)
3795 .write_begin = vbsf_write_begin,
3796 .write_end = simple_write_end,
3797#elif RTLNX_VER_MIN(2,5,45)
3798 .prepare_write = simple_prepare_write,
3799 .commit_write = simple_commit_write,
3800#endif
3801#if RTLNX_VER_MIN(2,4,10)
3802 .direct_IO = vbsf_direct_IO,
3803#endif
3804};
3805
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