vfsmod.h@ 78020

Last change on this file since 78020 was 77961, checked in by vboxsync, 6 years ago
linux/vboxsf: Don't set timestamps when changing the file size (open+O_TRUNC; ftrunctate), save a host call. Don't interpret setting mtime or changing the file size as a host file modification. bugref:9172
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 16.7 KB

Line
1	/* $Id: vfsmod.h 77961 2019-03-30 01:46:38Z vboxsync $ */
2	/** @file
3	* vboxsf - Linux Shared Folders VFS, internal header.
4	*/
5
6	/*
7	* Copyright (C) 2006-2019 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	DECLINLINE(void) set_nlink(struct inode *pInode, unsigned int cLinks)
103	{
104	pInode->i_nlink = cLinks;
105	}
106	#endif
107
108
109	/* global variables */
110	extern VBGLSFCLIENT g_SfClient;
111	extern spinlock_t g_SfHandleLock;
112	extern uint32_t g_uSfLastFunction;
113	extern uint64_t g_fSfFeatures;
114
115	extern struct inode_operations vbsf_dir_iops;
116	extern struct inode_operations vbsf_lnk_iops;
117	extern struct inode_operations vbsf_reg_iops;
118	extern struct file_operations vbsf_dir_fops;
119	extern struct file_operations vbsf_reg_fops;
120	extern struct dentry_operations vbsf_dentry_ops;
121	extern struct address_space_operations vbsf_reg_aops;
122
123
124	/**
125	* VBox specific per-mount (shared folder) information.
126	*/
127	struct vbsf_super_info {
128	VBGLSFMAP map;
129	struct nls_table *nls;
130	/** Set if the NLS table is UTF-8. */
131	bool fNlsIsUtf8;
132	int uid;
133	int gid;
134	int dmode;
135	int fmode;
136	int dmask;
137	int fmask;
138	/** Maximum number of pages to allow in an I/O buffer with the host.
139	* This applies to read and write operations. */
140	uint32_t cMaxIoPages;
141	/** The default directory buffer size. */
142	uint32_t cbDirBuf;
143	/** The time to live for directory entries in jiffies, zero if disabled. */
144	uint32_t cJiffiesDirCacheTTL;
145	/** The time to live for inode information in jiffies, zero if disabled. */
146	uint32_t cJiffiesInodeTTL;
147	/** The cache and coherency mode. */
148	enum vbsf_cache_mode enmCacheMode;
149	/** Mount tag for VBoxService automounter. @since 6.0 */
150	char szTag[32];
151	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) && LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 0)
152	/** The backing device info structure. */
153	struct backing_dev_info bdi;
154	#endif
155	/** The mount option value for /proc/mounts. */
156	int32_t msTTL;
157	/** The time to live for directory entries in milliseconds, for /proc/mounts. */
158	int32_t msDirCacheTTL;
159	/** The time to live for inode information in milliseconds, for /proc/mounts. */
160	int32_t msInodeTTL;
161	};
162
163	/* Following casts are here to prevent assignment of void * to
164	pointers of arbitrary type */
165	#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0)
166	# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->u.generic_sbp)
167	# define VBSF_SET_SUPER_INFO(sb, a_pSuperInfo) do { (sb)->u.generic_sbp = a_pSuperInfo; } while (0)
168	#else
169	# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->s_fs_info)
170	# define VBSF_SET_SUPER_INFO(sb, a_pSuperInfo) do { (sb)->s_fs_info = a_pSuperInfo;} while (0)
171	#endif
172
173
174	/**
175	* For associating inodes with host handles.
176	*
177	* This is necessary for address_space_operations::vbsf_writepage and allows
178	* optimizing stat, lookups and other operations on open files and directories.
179	*/
180	struct vbsf_handle {
181	/** List entry (head vbsf_inode_info::HandleList). */
182	RTLISTNODE Entry;
183	/** Host file/whatever handle. */
184	SHFLHANDLE hHost;
185	/** VBSF_HANDLE_F_XXX */
186	uint32_t fFlags;
187	/** Reference counter.
188	* Close the handle and free the structure when it reaches zero. */
189	uint32_t volatile cRefs;
190	#ifdef VBOX_STRICT
191	/** For strictness checks. */
192	struct vbsf_inode_info *pInodeInfo;
193	#endif
194	};
195
196	/** @name VBSF_HANDLE_F_XXX - Handle summary flags (vbsf_handle::fFlags).
197	* @{ */
198	#define VBSF_HANDLE_F_READ UINT32_C(0x00000001)
199	#define VBSF_HANDLE_F_WRITE UINT32_C(0x00000002)
200	#define VBSF_HANDLE_F_APPEND UINT32_C(0x00000004)
201	#define VBSF_HANDLE_F_FILE UINT32_C(0x00000010)
202	#define VBSF_HANDLE_F_DIR UINT32_C(0x00000020)
203	#define VBSF_HANDLE_F_ON_LIST UINT32_C(0x00000080)
204	#define VBSF_HANDLE_F_MAGIC_MASK UINT32_C(0xffffff00)
205	#define VBSF_HANDLE_F_MAGIC UINT32_C(0x75030700) /*< Maurice Ravel (1875-03-07). /
206	#define VBSF_HANDLE_F_MAGIC_DEAD UINT32_C(0x19371228)
207	/** @} */
208
209
210	/**
211	* VBox specific per-inode information.
212	*/
213	struct vbsf_inode_info {
214	/** Which file */
215	SHFLSTRING *path;
216	/** Some information was changed, update data on next revalidate */
217	bool force_restat;
218	/** The timestamp (jiffies) where the inode info was last updated. */
219	unsigned long ts_up_to_date;
220	/** The birth time. */
221	RTTIMESPEC BirthTime;
222
223	/** @name Host modification detection stats.
224	* @{ */
225	/** The raw modification time, for mapping invalidation purposes. */
226	RTTIMESPEC ModificationTime;
227	/** Copy of ModificationTime from the last time we wrote to the the file. */
228	RTTIMESPEC ModificationTimeAtOurLastWrite;
229	/** @} */
230
231	/** handle valid if a file was created with vbsf_create_worker until it will
232	* be opened with vbsf_reg_open()
233	* @todo r=bird: figure this one out... */
234	SHFLHANDLE handle;
235
236	/** List of open handles (struct vbsf_handle), protected by g_SfHandleLock. */
237	RTLISTANCHOR HandleList;
238	#ifdef VBOX_STRICT
239	uint32_t u32Magic;
240	# define SF_INODE_INFO_MAGIC UINT32_C(0x18620822) /*< Claude Debussy /
241	# define SF_INODE_INFO_MAGIC_DEAD UINT32_C(0x19180325)
242	#endif
243	};
244
245	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 19) \|\| defined(KERNEL_FC6)
246	/* FC6 kernel 2.6.18, vanilla kernel 2.6.19+ */
247	# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->i_private)
248	# define VBSF_SET_INODE_INFO(i, sf_i) (i)->i_private = sf_i
249	#else
250	/* vanilla kernel up to 2.6.18 */
251	# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->u.generic_ip)
252	# define VBSF_SET_INODE_INFO(i, sf_i) (i)->u.generic_ip = sf_i
253	#endif
254
255	extern void vbsf_init_inode(struct inode inode, struct vbsf_inode_info sf_i, PSHFLFSOBJINFO info,
256	struct vbsf_super_info *pSuperInfo);
257	extern void vbsf_update_inode(struct inode pInode, struct vbsf_inode_info pInodeInfo, PSHFLFSOBJINFO pObjInfo,
258	struct vbsf_super_info *pSuperInfo, bool fInodeLocked, unsigned fSetAttrs);
259	extern int vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced, bool fInodeLocked);
260	extern int vbsf_inode_revalidate_with_handle(struct dentry *dentry, SHFLHANDLE hHostFile, bool fForced, bool fInodeLocked);
261	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 18)
262	# if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
263	extern int vbsf_inode_getattr(const struct path path, struct kstat kstat, u32 request_mask, unsigned int query_flags);
264	# else
265	extern int vbsf_inode_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *kstat);
266	# endif
267	#else /* < 2.5.44 */
268	extern int vbsf_inode_revalidate(struct dentry *dentry);
269	#endif /* < 2.5.44 */
270	extern int vbsf_inode_setattr(struct dentry dentry, struct iattr iattr);
271
272
273	extern void vbsf_handle_drop_chain(struct vbsf_inode_info *pInodeInfo);
274	extern struct vbsf_handle vbsf_handle_find(struct vbsf_inode_info pInodeInfo, uint32_t fFlagsSet, uint32_t fFlagsClear);
275	extern uint32_t vbsf_handle_release_slow(struct vbsf_handle pHandle, struct vbsf_super_info pSuperInfo,
276	const char *pszCaller);
277	extern void vbsf_handle_append(struct vbsf_inode_info pInodeInfo, struct vbsf_handle pHandle);
278
279	/**
280	* Releases a handle.
281	*
282	* @returns New reference count.
283	* @param pHandle The handle to release.
284	* @param pSuperInfo The info structure for the shared folder associated
285	* with the handle.
286	* @param pszCaller The caller name (for logging failures).
287	*/
288	DECLINLINE(uint32_t) vbsf_handle_release(struct vbsf_handle pHandle, struct vbsf_super_info pSuperInfo, const char *pszCaller)
289	{
290	uint32_t cRefs;
291
292	Assert((pHandle->fFlags & VBSF_HANDLE_F_MAGIC_MASK) == VBSF_HANDLE_F_MAGIC);
293	Assert(pHandle->pInodeInfo);
294	Assert(pHandle->pInodeInfo && pHandle->pInodeInfo->u32Magic == SF_INODE_INFO_MAGIC);
295
296	cRefs = ASMAtomicDecU32(&pHandle->cRefs);
297	Assert(cRefs < _64M);
298	if (cRefs)
299	return cRefs;
300	return vbsf_handle_release_slow(pHandle, pSuperInfo, pszCaller);
301	}
302
303
304	/**
305	* VBox specific information for a regular file.
306	*/
307	struct vbsf_reg_info {
308	/** Handle tracking structure.
309	* @note Must be first! */
310	struct vbsf_handle Handle;
311	};
312
313	uint32_t vbsf_linux_oflags_to_vbox(unsigned fLnxOpen, uint32_t pfHandle, const char pszCaller);
314
315
316	/**
317	* VBox specific information for an open directory.
318	*/
319	struct vbsf_dir_info {
320	/** Handle tracking structure.
321	* @note Must be first! */
322	struct vbsf_handle Handle;
323	/** Semaphore protecting everything below. */
324	struct semaphore Lock;
325	/** A magic number (VBSF_DIR_INFO_MAGIC). */
326	uint32_t u32Magic;
327	/** Size of the buffer for directory entries. */
328	uint32_t cbBuf;
329	/** Buffer for directory entries on the physical heap. */
330	PSHFLDIRINFO pBuf;
331	/** Number of valid bytes in the buffer. */
332	uint32_t cbValid;
333	/** Number of entries left in the buffer. */
334	uint32_t cEntriesLeft;
335	/** The position of the next entry. Incremented by one for each entry. */
336	loff_t offPos;
337	/** The next entry. */
338	PSHFLDIRINFO pEntry;
339	/** Set if there are no more files. */
340	bool fNoMoreFiles;
341	};
342
343	/** Magic number for vbsf_dir_info::u32Magic (Robert Anson Heinlein). */
344	#define VBSF_DIR_INFO_MAGIC UINT32_C(0x19070707)
345	/** Value of vbsf_dir_info::u32Magic when freed. */
346	#define VBSF_DIR_INFO_MAGIC_DEAD UINT32_C(0x19880508)
347
348
349	/**
350	* Sets the update-jiffies value for a dentry.
351	*
352	* This is used together with vbsf_super_info::cJiffiesDirCacheTTL to reduce
353	* re-validation of dentry structures while walking.
354	*
355	* This used to be living in d_time, but since 4.9.0 that seems to have become
356	* unfashionable and d_fsdata is now used to for this purpose. We do this all
357	* the way back, since d_time seems only to have been used by the file system
358	* specific code (at least going back to 2.4.0).
359	*/
360	DECLINLINE(void) vbsf_dentry_set_update_jiffies(struct dentry *pDirEntry, unsigned long uToSet)
361	{
362	/SFLOG3(("vbsf_dentry_set_update_jiffies: %p: %lx -> %#lx\n", pDirEntry, (unsigned long)pDirEntry->d_fsdata, uToSet));/
363	pDirEntry->d_fsdata = (void *)uToSet;
364	}
365
366	/**
367	* Get the update-jiffies value for a dentry.
368	*/
369	DECLINLINE(unsigned long) vbsf_dentry_get_update_jiffies(struct dentry *pDirEntry)
370	{
371	return (unsigned long)pDirEntry->d_fsdata;
372	}
373
374	/**
375	* Invalidates the update TTL for the given directory entry so that it is
376	* revalidate the next time it is used.
377	* @param pDirEntry The directory entry cache entry to invalidate.
378	*/
379	DECLINLINE(void) vbsf_dentry_invalidate_ttl(struct dentry *pDirEntry)
380	{
381	vbsf_dentry_set_update_jiffies(pDirEntry, jiffies - INT32_MAX / 2);
382	}
383
384	/**
385	* Increase the time-to-live of @a pDirEntry and all ancestors.
386	* @param pDirEntry The directory entry cache entry which ancestors
387	* we should increase the TTL for.
388	*/
389	DECLINLINE(void) vbsf_dentry_chain_increase_ttl(struct dentry *pDirEntry)
390	{
391	#ifdef VBOX_STRICT
392	struct super_block * const pSuper = pDirEntry->d_sb;
393	#endif
394	unsigned long const uToSet = jiffies;
395	do {
396	Assert(pDirEntry->d_sb == pSuper);
397	vbsf_dentry_set_update_jiffies(pDirEntry, uToSet);
398	pDirEntry = pDirEntry->d_parent;
399	} while (!IS_ROOT(pDirEntry));
400	}
401
402	/**
403	* Increase the time-to-live of all ancestors.
404	* @param pDirEntry The directory entry cache entry which ancestors
405	* we should increase the TTL for.
406	*/
407	DECLINLINE(void) vbsf_dentry_chain_increase_parent_ttl(struct dentry *pDirEntry)
408	{
409	Assert(!pDirEntry->d_parent \|\| pDirEntry->d_parent->d_sb == pDirEntry->d_sb);
410	pDirEntry = pDirEntry->d_parent;
411	if (pDirEntry)
412	vbsf_dentry_chain_increase_ttl(pDirEntry);
413	}
414
415	/** Macro for getting the dentry for a struct file. */
416	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
417	# define VBSF_GET_F_DENTRY(f) file_dentry(f)
418	#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
419	# define VBSF_GET_F_DENTRY(f) (f->f_path.dentry)
420	#else
421	# define VBSF_GET_F_DENTRY(f) (f->f_dentry)
422	#endif
423
424	extern int vbsf_stat(const char caller, struct vbsf_super_info pSuperInfo, SHFLSTRING * path, PSHFLFSOBJINFO result,
425	int ok_to_fail);
426	extern int vbsf_path_from_dentry(struct vbsf_super_info pSuperInfo, struct vbsf_inode_info sf_i, struct dentry *dentry,
427	SHFLSTRING ** result, const char *caller);
428	extern int vbsf_nlscpy(struct vbsf_super_info pSuperInfo, char name, size_t name_bound_len,
429	const unsigned char *utf8_name, size_t utf8_len);
430	extern int vbsf_nls_to_shflstring(struct vbsf_super_info pSuperInfo, const char pszNls, PSHFLSTRING *ppString);
431
432
433	/**
434	* Converts Linux access permissions to VBox ones (mode & 0777).
435	*
436	* @note Currently identical.
437	* @sa sf_access_permissions_to_linux
438	*/
439	DECLINLINE(uint32_t) sf_access_permissions_to_vbox(int fAttr)
440	{
441	/* Access bits should be the same: */
442	AssertCompile(RTFS_UNIX_IRUSR == S_IRUSR);
443	AssertCompile(RTFS_UNIX_IWUSR == S_IWUSR);
444	AssertCompile(RTFS_UNIX_IXUSR == S_IXUSR);
445	AssertCompile(RTFS_UNIX_IRGRP == S_IRGRP);
446	AssertCompile(RTFS_UNIX_IWGRP == S_IWGRP);
447	AssertCompile(RTFS_UNIX_IXGRP == S_IXGRP);
448	AssertCompile(RTFS_UNIX_IROTH == S_IROTH);
449	AssertCompile(RTFS_UNIX_IWOTH == S_IWOTH);
450	AssertCompile(RTFS_UNIX_IXOTH == S_IXOTH);
451
452	return fAttr & RTFS_UNIX_ALL_ACCESS_PERMS;
453	}
454
455	#endif /* !GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h */

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source: vbox/trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.h@ 78020

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