vfsmod.h@ 82968

Last change on this file since 82968 was 82968, checked in by vboxsync, 5 years ago
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1	/* $Id: vfsmod.h 82968 2020-02-04 10:35:17Z vboxsync $ */
2	/** @file
3	* vboxsf - Linux Shared Folders VFS, internal header.
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	#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 LINUX_VERSION_CODE >= KERNEL_VERSION(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	/*
83	* inode compatibility glue.
84	*/
85	#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0)
86
87	DECLINLINE(loff_t) i_size_read(struct inode *pInode)
88	{
89	AssertCompile(sizeof(loff_t) == sizeof(uint64_t));
90	return ASMAtomicReadU64((uint64_t volatile *)&pInode->i_size);
91	}
92
93	DECLINLINE(void) i_size_write(struct inode *pInode, loff_t cbNew)
94	{
95	AssertCompile(sizeof(pInode->i_size) == sizeof(uint64_t));
96	ASMAtomicWriteU64((uint64_t volatile *)&pInode->i_size, cbNew);
97	}
98
99	#endif /* < 2.6.0 */
100
101	#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 2, 0) \
102	&& (!defined(RHEL_MAJOR) \|\| RHEL_MAJOR != 6 \|\| RHEL_MINOR < 10)
103	DECLINLINE(void) set_nlink(struct inode *pInode, unsigned int cLinks)
104	{
105	pInode->i_nlink = cLinks;
106	}
107	#endif
108
109
110	/* global variables */
111	extern VBGLSFCLIENT g_SfClient;
112	extern spinlock_t g_SfHandleLock;
113	extern uint32_t g_uSfLastFunction;
114	extern uint64_t g_fSfFeatures;
115
116	extern struct inode_operations vbsf_dir_iops;
117	extern struct inode_operations vbsf_lnk_iops;
118	extern struct inode_operations vbsf_reg_iops;
119	extern struct file_operations vbsf_dir_fops;
120	extern struct file_operations vbsf_reg_fops;
121	extern struct dentry_operations vbsf_dentry_ops;
122	extern struct address_space_operations vbsf_reg_aops;
123
124
125	/**
126	* VBox specific per-mount (shared folder) information.
127	*/
128	struct vbsf_super_info {
129	VBGLSFMAP map;
130	struct nls_table *nls;
131	/** Set if the NLS table is UTF-8. */
132	bool fNlsIsUtf8;
133	int uid;
134	int gid;
135	int dmode;
136	int fmode;
137	int dmask;
138	int fmask;
139	/** Maximum number of pages to allow in an I/O buffer with the host.
140	* This applies to read and write operations. */
141	uint32_t cMaxIoPages;
142	/** The default directory buffer size. */
143	uint32_t cbDirBuf;
144	/** The time to live for directory entries in jiffies, zero if disabled. */
145	uint32_t cJiffiesDirCacheTTL;
146	/** The time to live for inode information in jiffies, zero if disabled. */
147	uint32_t cJiffiesInodeTTL;
148	/** The cache and coherency mode. */
149	enum vbsf_cache_mode enmCacheMode;
150	/** Mount tag for VBoxService automounter. @since 6.0 */
151	char szTag[32];
152	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) && LINUX_VERSION_CODE < KERNEL_VERSION(4, 12, 0)
153	/** The backing device info structure. */
154	struct backing_dev_info bdi;
155	#endif
156	/** The mount option value for /proc/mounts. */
157	int32_t msTTL;
158	/** The time to live for directory entries in milliseconds, for /proc/mounts. */
159	int32_t msDirCacheTTL;
160	/** The time to live for inode information in milliseconds, for /proc/mounts. */
161	int32_t msInodeTTL;
162	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 0, 0) && LINUX_VERSION_CODE < KERNEL_VERSION(4, 2, 0)
163	/** 4.0 and 4.1 are missing noop_backing_dev_info export, so take down the
164	* initial value so we can restore it in vbsf_done_backing_dev(). (paranoia) */
165	struct backing_dev_info *bdi_org;
166	#endif
167	};
168
169	/* Following casts are here to prevent assignment of void * to
170	pointers of arbitrary type */
171	#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0)
172	# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->u.generic_sbp)
173	# define VBSF_SET_SUPER_INFO(sb, a_pSuperInfo) do { (sb)->u.generic_sbp = a_pSuperInfo; } while (0)
174	#else
175	# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->s_fs_info)
176	# define VBSF_SET_SUPER_INFO(sb, a_pSuperInfo) do { (sb)->s_fs_info = a_pSuperInfo;} while (0)
177	#endif
178
179
180	/**
181	* For associating inodes with host handles.
182	*
183	* This is necessary for address_space_operations::vbsf_writepage and allows
184	* optimizing stat, lookups and other operations on open files and directories.
185	*/
186	struct vbsf_handle {
187	/** List entry (head vbsf_inode_info::HandleList). */
188	RTLISTNODE Entry;
189	/** Host file/whatever handle. */
190	SHFLHANDLE hHost;
191	/** VBSF_HANDLE_F_XXX */
192	uint32_t fFlags;
193	/** Reference counter.
194	* Close the handle and free the structure when it reaches zero. */
195	uint32_t volatile cRefs;
196	#ifdef VBOX_STRICT
197	/** For strictness checks. */
198	struct vbsf_inode_info *pInodeInfo;
199	#endif
200	};
201
202	/** @name VBSF_HANDLE_F_XXX - Handle summary flags (vbsf_handle::fFlags).
203	* @{ */
204	#define VBSF_HANDLE_F_READ UINT32_C(0x00000001)
205	#define VBSF_HANDLE_F_WRITE UINT32_C(0x00000002)
206	#define VBSF_HANDLE_F_APPEND UINT32_C(0x00000004)
207	#define VBSF_HANDLE_F_FILE UINT32_C(0x00000010)
208	#define VBSF_HANDLE_F_DIR UINT32_C(0x00000020)
209	#define VBSF_HANDLE_F_ON_LIST UINT32_C(0x00000080)
210	#define VBSF_HANDLE_F_MAGIC_MASK UINT32_C(0xffffff00)
211	#define VBSF_HANDLE_F_MAGIC UINT32_C(0x75030700) /*< Maurice Ravel (1875-03-07). /
212	#define VBSF_HANDLE_F_MAGIC_DEAD UINT32_C(0x19371228)
213	/** @} */
214
215
216	/**
217	* VBox specific per-inode information.
218	*/
219	struct vbsf_inode_info {
220	/** Which file */
221	SHFLSTRING *path;
222	/** Some information was changed, update data on next revalidate */
223	bool force_restat;
224	/** The timestamp (jiffies) where the inode info was last updated. */
225	unsigned long ts_up_to_date;
226	/** The birth time. */
227	RTTIMESPEC BirthTime;
228
229	/** @name Host modification detection stats.
230	* @{ */
231	/** The raw modification time, for mapping invalidation purposes. */
232	RTTIMESPEC ModificationTime;
233	/** Copy of ModificationTime from the last time we wrote to the the file. */
234	RTTIMESPEC ModificationTimeAtOurLastWrite;
235	/** @} */
236
237	/** handle valid if a file was created with vbsf_create_worker until it will
238	* be opened with vbsf_reg_open()
239	* @todo r=bird: figure this one out... */
240	SHFLHANDLE handle;
241
242	/** List of open handles (struct vbsf_handle), protected by g_SfHandleLock. */
243	RTLISTANCHOR HandleList;
244	#ifdef VBOX_STRICT
245	uint32_t u32Magic;
246	# define SF_INODE_INFO_MAGIC UINT32_C(0x18620822) /*< Claude Debussy /
247	# define SF_INODE_INFO_MAGIC_DEAD UINT32_C(0x19180325)
248	#endif
249	};
250
251	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 19) \|\| defined(KERNEL_FC6)
252	/* FC6 kernel 2.6.18, vanilla kernel 2.6.19+ */
253	# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->i_private)
254	# define VBSF_SET_INODE_INFO(i, sf_i) (i)->i_private = sf_i
255	#else
256	/* vanilla kernel up to 2.6.18 */
257	# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->u.generic_ip)
258	# define VBSF_SET_INODE_INFO(i, sf_i) (i)->u.generic_ip = sf_i
259	#endif
260
261	extern void vbsf_init_inode(struct inode inode, struct vbsf_inode_info sf_i, PSHFLFSOBJINFO info,
262	struct vbsf_super_info *pSuperInfo);
263	extern void vbsf_update_inode(struct inode pInode, struct vbsf_inode_info pInodeInfo, PSHFLFSOBJINFO pObjInfo,
264	struct vbsf_super_info *pSuperInfo, bool fInodeLocked, unsigned fSetAttrs);
265	extern int vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced, bool fInodeLocked);
266	extern int vbsf_inode_revalidate_with_handle(struct dentry *dentry, SHFLHANDLE hHostFile, bool fForced, bool fInodeLocked);
267	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 18)
268	# if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
269	extern int vbsf_inode_getattr(const struct path path, struct kstat kstat, u32 request_mask, unsigned int query_flags);
270	# else
271	extern int vbsf_inode_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *kstat);
272	# endif
273	#else /* < 2.5.44 */
274	extern int vbsf_inode_revalidate(struct dentry *dentry);
275	#endif /* < 2.5.44 */
276	extern int vbsf_inode_setattr(struct dentry dentry, struct iattr iattr);
277
278
279	extern void vbsf_handle_drop_chain(struct vbsf_inode_info *pInodeInfo);
280	extern struct vbsf_handle vbsf_handle_find(struct vbsf_inode_info pInodeInfo, uint32_t fFlagsSet, uint32_t fFlagsClear);
281	extern uint32_t vbsf_handle_release_slow(struct vbsf_handle pHandle, struct vbsf_super_info pSuperInfo,
282	const char *pszCaller);
283	extern void vbsf_handle_append(struct vbsf_inode_info pInodeInfo, struct vbsf_handle pHandle);
284
285	/**
286	* Releases a handle.
287	*
288	* @returns New reference count.
289	* @param pHandle The handle to release.
290	* @param pSuperInfo The info structure for the shared folder associated
291	* with the handle.
292	* @param pszCaller The caller name (for logging failures).
293	*/
294	DECLINLINE(uint32_t) vbsf_handle_release(struct vbsf_handle pHandle, struct vbsf_super_info pSuperInfo, const char *pszCaller)
295	{
296	uint32_t cRefs;
297
298	Assert((pHandle->fFlags & VBSF_HANDLE_F_MAGIC_MASK) == VBSF_HANDLE_F_MAGIC);
299	Assert(pHandle->pInodeInfo);
300	Assert(pHandle->pInodeInfo && pHandle->pInodeInfo->u32Magic == SF_INODE_INFO_MAGIC);
301
302	cRefs = ASMAtomicDecU32(&pHandle->cRefs);
303	Assert(cRefs < _64M);
304	if (cRefs)
305	return cRefs;
306	return vbsf_handle_release_slow(pHandle, pSuperInfo, pszCaller);
307	}
308
309
310	/**
311	* VBox specific information for a regular file.
312	*/
313	struct vbsf_reg_info {
314	/** Handle tracking structure.
315	* @note Must be first! */
316	struct vbsf_handle Handle;
317	};
318
319	uint32_t vbsf_linux_oflags_to_vbox(unsigned fLnxOpen, uint32_t pfHandle, const char pszCaller);
320
321
322	/**
323	* VBox specific information for an open directory.
324	*/
325	struct vbsf_dir_info {
326	/** Handle tracking structure.
327	* @note Must be first! */
328	struct vbsf_handle Handle;
329	/** Semaphore protecting everything below. */
330	struct semaphore Lock;
331	/** A magic number (VBSF_DIR_INFO_MAGIC). */
332	uint32_t u32Magic;
333	/** Size of the buffer for directory entries. */
334	uint32_t cbBuf;
335	/** Buffer for directory entries on the physical heap. */
336	PSHFLDIRINFO pBuf;
337	/** Number of valid bytes in the buffer. */
338	uint32_t cbValid;
339	/** Number of entries left in the buffer. */
340	uint32_t cEntriesLeft;
341	/** The position of the next entry. Incremented by one for each entry. */
342	loff_t offPos;
343	/** The next entry. */
344	PSHFLDIRINFO pEntry;
345	/** Set if there are no more files. */
346	bool fNoMoreFiles;
347	};
348
349	/** Magic number for vbsf_dir_info::u32Magic (Robert Anson Heinlein). */
350	#define VBSF_DIR_INFO_MAGIC UINT32_C(0x19070707)
351	/** Value of vbsf_dir_info::u32Magic when freed. */
352	#define VBSF_DIR_INFO_MAGIC_DEAD UINT32_C(0x19880508)
353
354
355	/**
356	* Sets the update-jiffies value for a dentry.
357	*
358	* This is used together with vbsf_super_info::cJiffiesDirCacheTTL to reduce
359	* re-validation of dentry structures while walking.
360	*
361	* This used to be living in d_time, but since 4.9.0 that seems to have become
362	* unfashionable and d_fsdata is now used to for this purpose. We do this all
363	* the way back, since d_time seems only to have been used by the file system
364	* specific code (at least going back to 2.4.0).
365	*/
366	DECLINLINE(void) vbsf_dentry_set_update_jiffies(struct dentry *pDirEntry, unsigned long uToSet)
367	{
368	/SFLOG3(("vbsf_dentry_set_update_jiffies: %p: %lx -> %#lx\n", pDirEntry, (unsigned long)pDirEntry->d_fsdata, uToSet));/
369	pDirEntry->d_fsdata = (void *)uToSet;
370	}
371
372	/**
373	* Get the update-jiffies value for a dentry.
374	*/
375	DECLINLINE(unsigned long) vbsf_dentry_get_update_jiffies(struct dentry *pDirEntry)
376	{
377	return (unsigned long)pDirEntry->d_fsdata;
378	}
379
380	/**
381	* Invalidates the update TTL for the given directory entry so that it is
382	* revalidate the next time it is used.
383	* @param pDirEntry The directory entry cache entry to invalidate.
384	*/
385	DECLINLINE(void) vbsf_dentry_invalidate_ttl(struct dentry *pDirEntry)
386	{
387	vbsf_dentry_set_update_jiffies(pDirEntry, jiffies - INT32_MAX / 2);
388	}
389
390	/**
391	* Increase the time-to-live of @a pDirEntry and all ancestors.
392	* @param pDirEntry The directory entry cache entry which ancestors
393	* we should increase the TTL for.
394	*/
395	DECLINLINE(void) vbsf_dentry_chain_increase_ttl(struct dentry *pDirEntry)
396	{
397	#ifdef VBOX_STRICT
398	struct super_block * const pSuper = pDirEntry->d_sb;
399	#endif
400	unsigned long const uToSet = jiffies;
401	do {
402	Assert(pDirEntry->d_sb == pSuper);
403	vbsf_dentry_set_update_jiffies(pDirEntry, uToSet);
404	pDirEntry = pDirEntry->d_parent;
405	} while (!IS_ROOT(pDirEntry));
406	}
407
408	/**
409	* Increase the time-to-live of all ancestors.
410	* @param pDirEntry The directory entry cache entry which ancestors
411	* we should increase the TTL for.
412	*/
413	DECLINLINE(void) vbsf_dentry_chain_increase_parent_ttl(struct dentry *pDirEntry)
414	{
415	Assert(!pDirEntry->d_parent \|\| pDirEntry->d_parent->d_sb == pDirEntry->d_sb);
416	pDirEntry = pDirEntry->d_parent;
417	if (pDirEntry)
418	vbsf_dentry_chain_increase_ttl(pDirEntry);
419	}
420
421	/** Macro for getting the dentry for a struct file. */
422	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
423	# define VBSF_GET_F_DENTRY(f) file_dentry(f)
424	#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
425	# define VBSF_GET_F_DENTRY(f) (f->f_path.dentry)
426	#else
427	# define VBSF_GET_F_DENTRY(f) (f->f_dentry)
428	#endif
429
430	extern int vbsf_stat(const char caller, struct vbsf_super_info pSuperInfo, SHFLSTRING * path, PSHFLFSOBJINFO result,
431	int ok_to_fail);
432	extern int vbsf_path_from_dentry(struct vbsf_super_info pSuperInfo, struct vbsf_inode_info sf_i, struct dentry *dentry,
433	SHFLSTRING ** result, const char *caller);
434	extern int vbsf_nlscpy(struct vbsf_super_info pSuperInfo, char name, size_t name_bound_len,
435	const unsigned char *utf8_name, size_t utf8_len);
436	extern int vbsf_nls_to_shflstring(struct vbsf_super_info pSuperInfo, const char pszNls, PSHFLSTRING *ppString);
437
438
439	/**
440	* Converts Linux access permissions to VBox ones (mode & 0777).
441	*
442	* @note Currently identical.
443	* @sa sf_access_permissions_to_linux
444	*/
445	DECLINLINE(uint32_t) sf_access_permissions_to_vbox(int fAttr)
446	{
447	/* Access bits should be the same: */
448	AssertCompile(RTFS_UNIX_IRUSR == S_IRUSR);
449	AssertCompile(RTFS_UNIX_IWUSR == S_IWUSR);
450	AssertCompile(RTFS_UNIX_IXUSR == S_IXUSR);
451	AssertCompile(RTFS_UNIX_IRGRP == S_IRGRP);
452	AssertCompile(RTFS_UNIX_IWGRP == S_IWGRP);
453	AssertCompile(RTFS_UNIX_IXGRP == S_IXGRP);
454	AssertCompile(RTFS_UNIX_IROTH == S_IROTH);
455	AssertCompile(RTFS_UNIX_IWOTH == S_IWOTH);
456	AssertCompile(RTFS_UNIX_IXOTH == S_IXOTH);
457
458	return fAttr & RTFS_UNIX_ALL_ACCESS_PERMS;
459	}
460
461	#endif /* !GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h */

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source: vbox/trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.h@ 82968

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