vfsmod.h@ 98278

Last change on this file since 98278 was 98103, checked in by vboxsync, 2 years ago
Copyright year updates by scm.
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1	/* $Id: vfsmod.h 98103 2023-01-17 14:15:46Z vboxsync $ */
2	/** @file
3	* vboxsf - Linux Shared Folders VFS, internal header.
4	*/
5
6	/*
7	* Copyright (C) 2006-2023 Oracle and/or its affiliates.
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	#ifndef GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h
32	#define GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h
33	#ifndef RT_WITHOUT_PRAGMA_ONCE
34	# pragma once
35	#endif
36
37	#if 0 /* Enables strict checks. */
38	# define RT_STRICT
39	# define VBOX_STRICT
40	#endif
41
42	#define LOG_GROUP LOG_GROUP_SHARED_FOLDERS
43	#include "the-linux-kernel.h"
44	#include <iprt/list.h>
45	#include <iprt/asm.h>
46	#include <VBox/log.h>
47
48	#if RTLNX_VER_MIN(2,6,0)
49	# include <linux/backing-dev.h>
50	#endif
51
52	#include <VBox/VBoxGuestLibSharedFolders.h>
53	#include <VBox/VBoxGuestLibSharedFoldersInline.h>
54	#include <iprt/asm.h>
55	#include "vbsfmount.h"
56
57
58	/*
59	* Logging wrappers.
60	*/
61	#if 1
62	# define TRACE() LogFunc(("tracepoint\n"))
63	# define SFLOG(aArgs) Log(aArgs)
64	# define SFLOGFLOW(aArgs) LogFlow(aArgs)
65	# define SFLOG2(aArgs) Log2(aArgs)
66	# define SFLOG3(aArgs) Log3(aArgs)
67	# define SFLOGRELBOTH(aArgs) LogRel(aArgs)
68	# ifdef LOG_ENABLED
69	# define SFLOG_ENABLED 1
70	# endif
71	#else
72	# define TRACE() RTLogBackdoorPrintf("%s: tracepoint\n", __FUNCTION__)
73	# define SFLOG(aArgs) RTLogBackdoorPrintf aArgs
74	# define SFLOGFLOW(aArgs) RTLogBackdoorPrintf aArgs
75	# define SFLOG2(aArgs) RTLogBackdoorPrintf aArgs
76	# define SFLOG3(aArgs) RTLogBackdoorPrintf aArgs
77	# define SFLOG_ENABLED 1
78	# define SFLOGRELBOTH(aArgs) do { RTLogBackdoorPrintf aArgs; printk aArgs; } while (0)
79	#endif
80
81
82	/* Simmilar workaround for CONFIG_FORTIFY_SOURCE kernel config option as we have for host drivers.
83	* In Linux 5.18-rc1, memcpy became a wrapper which does fortify checks
84	* before triggering __underlying_memcpy() call. We do not pass these checks in some places so
85	* bypass them for now. */
86	#if RTLNX_VER_MIN(5,18,0) && !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
87	# define VBOX_LINUX_MEMCPY __underlying_memcpy
88	#else
89	#define VBOX_LINUX_MEMCPY memcpy
90	#endif
91
92
93	/*
94	* inode compatibility glue.
95	*/
96	#if RTLNX_VER_MAX(2,6,0)
97
98	DECLINLINE(loff_t) i_size_read(struct inode *pInode)
99	{
100	AssertCompile(sizeof(loff_t) == sizeof(uint64_t));
101	return ASMAtomicReadU64((uint64_t volatile *)&pInode->i_size);
102	}
103
104	DECLINLINE(void) i_size_write(struct inode *pInode, loff_t cbNew)
105	{
106	AssertCompile(sizeof(pInode->i_size) == sizeof(uint64_t));
107	ASMAtomicWriteU64((uint64_t volatile *)&pInode->i_size, cbNew);
108	}
109
110	#endif /* < 2.6.0 */
111
112	#if RTLNX_VER_MAX(3,2,0) && !RTLNX_RHEL_MIN(6, 10)
113	DECLINLINE(void) set_nlink(struct inode *pInode, unsigned int cLinks)
114	{
115	pInode->i_nlink = cLinks;
116	}
117	#endif
118
119
120	/* global variables */
121	extern VBGLSFCLIENT g_SfClient;
122	extern spinlock_t g_SfHandleLock;
123	extern uint32_t g_uSfLastFunction;
124	extern uint64_t g_fSfFeatures;
125
126	extern struct inode_operations vbsf_dir_iops;
127	extern struct inode_operations vbsf_lnk_iops;
128	extern struct inode_operations vbsf_reg_iops;
129	extern struct file_operations vbsf_dir_fops;
130	extern struct file_operations vbsf_reg_fops;
131	extern struct dentry_operations vbsf_dentry_ops;
132	extern struct address_space_operations vbsf_reg_aops;
133
134
135	/**
136	* VBox specific per-mount (shared folder) information.
137	*/
138	struct vbsf_super_info {
139	VBGLSFMAP map;
140	struct nls_table *nls;
141	/** Set if the NLS table is UTF-8. */
142	bool fNlsIsUtf8;
143	int uid;
144	int gid;
145	int dmode;
146	int fmode;
147	int dmask;
148	int fmask;
149	/** Maximum number of pages to allow in an I/O buffer with the host.
150	* This applies to read and write operations. */
151	uint32_t cMaxIoPages;
152	/** The default directory buffer size. */
153	uint32_t cbDirBuf;
154	/** The time to live for directory entries in jiffies, zero if disabled. */
155	uint32_t cJiffiesDirCacheTTL;
156	/** The time to live for inode information in jiffies, zero if disabled. */
157	uint32_t cJiffiesInodeTTL;
158	/** The cache and coherency mode. */
159	enum vbsf_cache_mode enmCacheMode;
160	/** Mount tag for VBoxService automounter. @since 6.0 */
161	char szTag[32];
162	#if RTLNX_VER_RANGE(2,6,0, 4,12,0)
163	/** The backing device info structure. */
164	struct backing_dev_info bdi;
165	#endif
166	/** The mount option value for /proc/mounts. */
167	int32_t msTTL;
168	/** The time to live for directory entries in milliseconds, for /proc/mounts. */
169	int32_t msDirCacheTTL;
170	/** The time to live for inode information in milliseconds, for /proc/mounts. */
171	int32_t msInodeTTL;
172	#if RTLNX_VER_RANGE(4,0,0, 4,2,0)
173	/** 4.0 and 4.1 are missing noop_backing_dev_info export, so take down the
174	* initial value so we can restore it in vbsf_done_backing_dev(). (paranoia) */
175	struct backing_dev_info *bdi_org;
176	#endif
177	};
178
179	/* Following casts are here to prevent assignment of void * to
180	pointers of arbitrary type */
181	#if RTLNX_VER_MAX(2,6,0)
182	# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->u.generic_sbp)
183	# define VBSF_SET_SUPER_INFO(sb, a_pSuperInfo) do { (sb)->u.generic_sbp = a_pSuperInfo; } while (0)
184	#else
185	# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->s_fs_info)
186	# define VBSF_SET_SUPER_INFO(sb, a_pSuperInfo) do { (sb)->s_fs_info = a_pSuperInfo;} while (0)
187	#endif
188
189
190	/**
191	* For associating inodes with host handles.
192	*
193	* This is necessary for address_space_operations::vbsf_writepage and allows
194	* optimizing stat, lookups and other operations on open files and directories.
195	*/
196	struct vbsf_handle {
197	/** List entry (head vbsf_inode_info::HandleList). */
198	RTLISTNODE Entry;
199	/** Host file/whatever handle. */
200	SHFLHANDLE hHost;
201	/** VBSF_HANDLE_F_XXX */
202	uint32_t fFlags;
203	/** Reference counter.
204	* Close the handle and free the structure when it reaches zero. */
205	uint32_t volatile cRefs;
206	#ifdef VBOX_STRICT
207	/** For strictness checks. */
208	struct vbsf_inode_info *pInodeInfo;
209	#endif
210	};
211
212	/** @name VBSF_HANDLE_F_XXX - Handle summary flags (vbsf_handle::fFlags).
213	* @{ */
214	#define VBSF_HANDLE_F_READ UINT32_C(0x00000001)
215	#define VBSF_HANDLE_F_WRITE UINT32_C(0x00000002)
216	#define VBSF_HANDLE_F_APPEND UINT32_C(0x00000004)
217	#define VBSF_HANDLE_F_FILE UINT32_C(0x00000010)
218	#define VBSF_HANDLE_F_DIR UINT32_C(0x00000020)
219	#define VBSF_HANDLE_F_ON_LIST UINT32_C(0x00000080)
220	#define VBSF_HANDLE_F_MAGIC_MASK UINT32_C(0xffffff00)
221	#define VBSF_HANDLE_F_MAGIC UINT32_C(0x75030700) /*< Maurice Ravel (1875-03-07). /
222	#define VBSF_HANDLE_F_MAGIC_DEAD UINT32_C(0x19371228)
223	/** @} */
224
225
226	/**
227	* VBox specific per-inode information.
228	*/
229	struct vbsf_inode_info {
230	/** Which file */
231	SHFLSTRING *path;
232	/** Some information was changed, update data on next revalidate */
233	bool force_restat;
234	/** The timestamp (jiffies) where the inode info was last updated. */
235	unsigned long ts_up_to_date;
236	/** The birth time. */
237	RTTIMESPEC BirthTime;
238
239	/** @name Host modification detection stats.
240	* @{ */
241	/** The raw modification time, for mapping invalidation purposes. */
242	RTTIMESPEC ModificationTime;
243	/** Copy of ModificationTime from the last time we wrote to the the file. */
244	RTTIMESPEC ModificationTimeAtOurLastWrite;
245	/** @} */
246
247	/** handle valid if a file was created with vbsf_create_worker until it will
248	* be opened with vbsf_reg_open()
249	* @todo r=bird: figure this one out... */
250	SHFLHANDLE handle;
251
252	/** List of open handles (struct vbsf_handle), protected by g_SfHandleLock. */
253	RTLISTANCHOR HandleList;
254	#ifdef VBOX_STRICT
255	uint32_t u32Magic;
256	# define SF_INODE_INFO_MAGIC UINT32_C(0x18620822) /*< Claude Debussy /
257	# define SF_INODE_INFO_MAGIC_DEAD UINT32_C(0x19180325)
258	#endif
259	};
260
261	#if RTLNX_VER_MIN(2,6,19) \|\| defined(KERNEL_FC6)
262	/* FC6 kernel 2.6.18, vanilla kernel 2.6.19+ */
263	# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->i_private)
264	# define VBSF_SET_INODE_INFO(i, sf_i) (i)->i_private = sf_i
265	#else
266	/* vanilla kernel up to 2.6.18 */
267	# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->u.generic_ip)
268	# define VBSF_SET_INODE_INFO(i, sf_i) (i)->u.generic_ip = sf_i
269	#endif
270
271	extern void vbsf_init_inode(struct inode inode, struct vbsf_inode_info sf_i, PSHFLFSOBJINFO info,
272	struct vbsf_super_info *pSuperInfo);
273	extern void vbsf_update_inode(struct inode pInode, struct vbsf_inode_info pInodeInfo, PSHFLFSOBJINFO pObjInfo,
274	struct vbsf_super_info *pSuperInfo, bool fInodeLocked, unsigned fSetAttrs);
275	extern int vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced, bool fInodeLocked);
276	extern int vbsf_inode_revalidate_with_handle(struct dentry *dentry, SHFLHANDLE hHostFile, bool fForced, bool fInodeLocked);
277	#if RTLNX_VER_MIN(2,5,18)
278	# if RTLNX_VER_MIN(5,12,0)
279	extern int vbsf_inode_getattr(struct user_namespace ns, const struct path path,
280	struct kstat *kstat, u32 request_mask, unsigned int query_flags);
281	# elif RTLNX_VER_MIN(4,11,0)
282	extern int vbsf_inode_getattr(const struct path path, struct kstat kstat, u32 request_mask, unsigned int query_flags);
283	# else
284	extern int vbsf_inode_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *kstat);
285	# endif
286	#else /* < 2.5.44 */
287	extern int vbsf_inode_revalidate(struct dentry *dentry);
288	#endif /* < 2.5.44 */
289	#if RTLNX_VER_MIN(5,12,0)
290	extern int vbsf_inode_setattr(struct user_namespace ns, struct dentry dentry, struct iattr *iattr);
291	#else
292	extern int vbsf_inode_setattr(struct dentry dentry, struct iattr iattr);
293	#endif
294
295
296	extern void vbsf_handle_drop_chain(struct vbsf_inode_info *pInodeInfo);
297	extern struct vbsf_handle vbsf_handle_find(struct vbsf_inode_info pInodeInfo, uint32_t fFlagsSet, uint32_t fFlagsClear);
298	extern uint32_t vbsf_handle_release_slow(struct vbsf_handle pHandle, struct vbsf_super_info pSuperInfo,
299	const char *pszCaller);
300	extern void vbsf_handle_append(struct vbsf_inode_info pInodeInfo, struct vbsf_handle pHandle);
301
302	/**
303	* Releases a handle.
304	*
305	* @returns New reference count.
306	* @param pHandle The handle to release.
307	* @param pSuperInfo The info structure for the shared folder associated
308	* with the handle.
309	* @param pszCaller The caller name (for logging failures).
310	*/
311	DECLINLINE(uint32_t) vbsf_handle_release(struct vbsf_handle pHandle, struct vbsf_super_info pSuperInfo, const char *pszCaller)
312	{
313	uint32_t cRefs;
314
315	Assert((pHandle->fFlags & VBSF_HANDLE_F_MAGIC_MASK) == VBSF_HANDLE_F_MAGIC);
316	Assert(pHandle->pInodeInfo);
317	Assert(pHandle->pInodeInfo && pHandle->pInodeInfo->u32Magic == SF_INODE_INFO_MAGIC);
318
319	cRefs = ASMAtomicDecU32(&pHandle->cRefs);
320	Assert(cRefs < _64M);
321	if (cRefs)
322	return cRefs;
323	return vbsf_handle_release_slow(pHandle, pSuperInfo, pszCaller);
324	}
325
326
327	/**
328	* VBox specific information for a regular file.
329	*/
330	struct vbsf_reg_info {
331	/** Handle tracking structure.
332	* @note Must be first! */
333	struct vbsf_handle Handle;
334	};
335
336	uint32_t vbsf_linux_oflags_to_vbox(unsigned fLnxOpen, uint32_t pfHandle, const char pszCaller);
337
338
339	/**
340	* VBox specific information for an open directory.
341	*/
342	struct vbsf_dir_info {
343	/** Handle tracking structure.
344	* @note Must be first! */
345	struct vbsf_handle Handle;
346	/** Semaphore protecting everything below. */
347	struct semaphore Lock;
348	/** A magic number (VBSF_DIR_INFO_MAGIC). */
349	uint32_t u32Magic;
350	/** Size of the buffer for directory entries. */
351	uint32_t cbBuf;
352	/** Buffer for directory entries on the physical heap. */
353	PSHFLDIRINFO pBuf;
354	/** Number of valid bytes in the buffer. */
355	uint32_t cbValid;
356	/** Number of entries left in the buffer. */
357	uint32_t cEntriesLeft;
358	/** The position of the next entry. Incremented by one for each entry. */
359	loff_t offPos;
360	/** The next entry. */
361	PSHFLDIRINFO pEntry;
362	/** Set if there are no more files. */
363	bool fNoMoreFiles;
364	};
365
366	/** Magic number for vbsf_dir_info::u32Magic (Robert Anson Heinlein). */
367	#define VBSF_DIR_INFO_MAGIC UINT32_C(0x19070707)
368	/** Value of vbsf_dir_info::u32Magic when freed. */
369	#define VBSF_DIR_INFO_MAGIC_DEAD UINT32_C(0x19880508)
370
371
372	/**
373	* Sets the update-jiffies value for a dentry.
374	*
375	* This is used together with vbsf_super_info::cJiffiesDirCacheTTL to reduce
376	* re-validation of dentry structures while walking.
377	*
378	* This used to be living in d_time, but since 4.9.0 that seems to have become
379	* unfashionable and d_fsdata is now used to for this purpose. We do this all
380	* the way back, since d_time seems only to have been used by the file system
381	* specific code (at least going back to 2.4.0).
382	*/
383	DECLINLINE(void) vbsf_dentry_set_update_jiffies(struct dentry *pDirEntry, unsigned long uToSet)
384	{
385	/SFLOG3(("vbsf_dentry_set_update_jiffies: %p: %lx -> %#lx\n", pDirEntry, (unsigned long)pDirEntry->d_fsdata, uToSet));/
386	pDirEntry->d_fsdata = (void *)uToSet;
387	}
388
389	/**
390	* Get the update-jiffies value for a dentry.
391	*/
392	DECLINLINE(unsigned long) vbsf_dentry_get_update_jiffies(struct dentry *pDirEntry)
393	{
394	return (unsigned long)pDirEntry->d_fsdata;
395	}
396
397	/**
398	* Invalidates the update TTL for the given directory entry so that it is
399	* revalidate the next time it is used.
400	* @param pDirEntry The directory entry cache entry to invalidate.
401	*/
402	DECLINLINE(void) vbsf_dentry_invalidate_ttl(struct dentry *pDirEntry)
403	{
404	vbsf_dentry_set_update_jiffies(pDirEntry, jiffies - INT32_MAX / 2);
405	}
406
407	/**
408	* Increase the time-to-live of @a pDirEntry and all ancestors.
409	* @param pDirEntry The directory entry cache entry which ancestors
410	* we should increase the TTL for.
411	*/
412	DECLINLINE(void) vbsf_dentry_chain_increase_ttl(struct dentry *pDirEntry)
413	{
414	#ifdef VBOX_STRICT
415	struct super_block * const pSuper = pDirEntry->d_sb;
416	#endif
417	unsigned long const uToSet = jiffies;
418	do {
419	Assert(pDirEntry->d_sb == pSuper);
420	vbsf_dentry_set_update_jiffies(pDirEntry, uToSet);
421	pDirEntry = pDirEntry->d_parent;
422	} while (!IS_ROOT(pDirEntry));
423	}
424
425	/**
426	* Increase the time-to-live of all ancestors.
427	* @param pDirEntry The directory entry cache entry which ancestors
428	* we should increase the TTL for.
429	*/
430	DECLINLINE(void) vbsf_dentry_chain_increase_parent_ttl(struct dentry *pDirEntry)
431	{
432	Assert(!pDirEntry->d_parent \|\| pDirEntry->d_parent->d_sb == pDirEntry->d_sb);
433	pDirEntry = pDirEntry->d_parent;
434	if (pDirEntry)
435	vbsf_dentry_chain_increase_ttl(pDirEntry);
436	}
437
438	/** Macro for getting the dentry for a struct file. */
439	#if RTLNX_VER_MIN(4,6,0)
440	# define VBSF_GET_F_DENTRY(f) file_dentry(f)
441	#elif RTLNX_VER_MIN(2,6,20)
442	# define VBSF_GET_F_DENTRY(f) (f->f_path.dentry)
443	#else
444	# define VBSF_GET_F_DENTRY(f) (f->f_dentry)
445	#endif
446
447	/**
448	* Macro for checking if the 'data' argument passed in via mount(2) was supplied
449	* by the mount.vboxsf command line utility as a page of data containing the
450	* vbsf_mount_info_new structure.
451	*/
452	#define VBSF_IS_MOUNT_VBOXSF_DATA(data) \
453	(((struct vbsf_mount_info_new *)data)->nullchar == '\0' && \
454	((struct vbsf_mount_info_new *)data)->signature[0] == VBSF_MOUNT_SIGNATURE_BYTE_0 && \
455	((struct vbsf_mount_info_new *)data)->signature[1] == VBSF_MOUNT_SIGNATURE_BYTE_1 && \
456	((struct vbsf_mount_info_new *)data)->signature[2] == VBSF_MOUNT_SIGNATURE_BYTE_2)
457
458	extern int vbsf_stat(const char caller, struct vbsf_super_info pSuperInfo, SHFLSTRING * path, PSHFLFSOBJINFO result,
459	int ok_to_fail);
460	extern int vbsf_path_from_dentry(struct vbsf_super_info pSuperInfo, struct vbsf_inode_info sf_i, struct dentry *dentry,
461	SHFLSTRING ** result, const char *caller);
462	extern int vbsf_nlscpy(struct vbsf_super_info pSuperInfo, char name, size_t name_bound_len,
463	const unsigned char *utf8_name, size_t utf8_len);
464	extern int vbsf_nls_to_shflstring(struct vbsf_super_info pSuperInfo, const char pszNls, PSHFLSTRING *ppString);
465
466
467	/**
468	* Converts Linux access permissions to VBox ones (mode & 0777).
469	*
470	* @note Currently identical.
471	* @sa sf_access_permissions_to_linux
472	*/
473	DECLINLINE(uint32_t) sf_access_permissions_to_vbox(int fAttr)
474	{
475	/* Access bits should be the same: */
476	AssertCompile(RTFS_UNIX_IRUSR == S_IRUSR);
477	AssertCompile(RTFS_UNIX_IWUSR == S_IWUSR);
478	AssertCompile(RTFS_UNIX_IXUSR == S_IXUSR);
479	AssertCompile(RTFS_UNIX_IRGRP == S_IRGRP);
480	AssertCompile(RTFS_UNIX_IWGRP == S_IWGRP);
481	AssertCompile(RTFS_UNIX_IXGRP == S_IXGRP);
482	AssertCompile(RTFS_UNIX_IROTH == S_IROTH);
483	AssertCompile(RTFS_UNIX_IWOTH == S_IWOTH);
484	AssertCompile(RTFS_UNIX_IXOTH == S_IXOTH);
485
486	return fAttr & RTFS_UNIX_ALL_ACCESS_PERMS;
487	}
488
489	#endif /* !GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h */

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source: vbox/trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.h@ 98278

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