vfsmod.h@ 77858

Last change on this file since 77858 was 77858, checked in by vboxsync, 6 years ago
linux/vboxsf: Cleaning up the symlink related code and making it work on 2.4.x too. Untested. bugref:9172
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 15.2 KB

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1	/* $Id: vfsmod.h 77858 2019-03-24 00:10:24Z 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	/** time-to-live value for direntry and inode info in jiffies.
133	* Zero == disabled. */
134	unsigned long ttl;
135	/** The mount option value for /proc/mounts. */
136	int ttl_msec;
137	int uid;
138	int gid;
139	int dmode;
140	int fmode;
141	int dmask;
142	int fmask;
143	/** Maximum number of pages to allow in an I/O buffer with the host.
144	* This applies to read and write operations. */
145	uint32_t cMaxIoPages;
146	/** Mount tag for VBoxService automounter. @since 6.0 */
147	char tag[32];
148	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 0) && LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 0)
149	/** The backing device info structure. */
150	struct backing_dev_info bdi;
151	#endif
152	};
153
154	/* Following casts are here to prevent assignment of void * to
155	pointers of arbitrary type */
156	#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 0)
157	# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->u.generic_sbp)
158	# define VBSF_SET_SUPER_INFO(sb, sf_g) do { (sb)->u.generic_sbp = sf_g; } while (0)
159	#else
160	# define VBSF_GET_SUPER_INFO(sb) ((struct vbsf_super_info *)(sb)->s_fs_info)
161	# define VBSF_SET_SUPER_INFO(sb, sf_g) do { (sb)->s_fs_info = sf_g;} while (0)
162	#endif
163
164
165	/**
166	* For associating inodes with host handles.
167	*
168	* This is necessary for address_space_operations::vbsf_writepage and allows
169	* optimizing stat, lookups and other operations on open files and directories.
170	*/
171	struct vbsf_handle {
172	/** List entry (head vbsf_inode_info::HandleList). */
173	RTLISTNODE Entry;
174	/** Host file/whatever handle. */
175	SHFLHANDLE hHost;
176	/** VBSF_HANDLE_F_XXX */
177	uint32_t fFlags;
178	/** Reference counter.
179	* Close the handle and free the structure when it reaches zero. */
180	uint32_t volatile cRefs;
181	#ifdef VBOX_STRICT
182	/** For strictness checks. */
183	struct vbsf_inode_info *pInodeInfo;
184	#endif
185	};
186
187	/** @name VBSF_HANDLE_F_XXX - Handle summary flags (vbsf_handle::fFlags).
188	* @{ */
189	#define VBSF_HANDLE_F_READ UINT32_C(0x00000001)
190	#define VBSF_HANDLE_F_WRITE UINT32_C(0x00000002)
191	#define VBSF_HANDLE_F_APPEND UINT32_C(0x00000004)
192	#define VBSF_HANDLE_F_FILE UINT32_C(0x00000010)
193	#define VBSF_HANDLE_F_DIR UINT32_C(0x00000020)
194	#define VBSF_HANDLE_F_ON_LIST UINT32_C(0x00000080)
195	#define VBSF_HANDLE_F_MAGIC_MASK UINT32_C(0xffffff00)
196	#define VBSF_HANDLE_F_MAGIC UINT32_C(0x75030700) /*< Maurice Ravel (1875-03-07). /
197	#define VBSF_HANDLE_F_MAGIC_DEAD UINT32_C(0x19371228)
198	/** @} */
199
200
201	/**
202	* VBox specific per-inode information.
203	*/
204	struct vbsf_inode_info {
205	/** Which file */
206	SHFLSTRING *path;
207	/** Some information was changed, update data on next revalidate */
208	bool force_restat;
209	/** The timestamp (jiffies) where the inode info was last updated. */
210	unsigned long ts_up_to_date;
211	/** The birth time. */
212	RTTIMESPEC BirthTime;
213
214	/** handle valid if a file was created with vbsf_create_worker until it will
215	* be opened with vbsf_reg_open()
216	* @todo r=bird: figure this one out... */
217	SHFLHANDLE handle;
218
219	/** List of open handles (struct vbsf_handle), protected by g_SfHandleLock. */
220	RTLISTANCHOR HandleList;
221	#ifdef VBOX_STRICT
222	uint32_t u32Magic;
223	# define SF_INODE_INFO_MAGIC UINT32_C(0x18620822) /*< Claude Debussy /
224	# define SF_INODE_INFO_MAGIC_DEAD UINT32_C(0x19180325)
225	#endif
226	};
227
228	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 19) \|\| defined(KERNEL_FC6)
229	/* FC6 kernel 2.6.18, vanilla kernel 2.6.19+ */
230	# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->i_private)
231	# define VBSF_SET_INODE_INFO(i, sf_i) (i)->i_private = sf_i
232	#else
233	/* vanilla kernel up to 2.6.18 */
234	# define VBSF_GET_INODE_INFO(i) ((struct vbsf_inode_info *) (i)->u.generic_ip)
235	# define VBSF_SET_INODE_INFO(i, sf_i) (i)->u.generic_ip = sf_i
236	#endif
237
238	extern void vbsf_init_inode(struct inode inode, struct vbsf_inode_info sf_i, PSHFLFSOBJINFO info, struct vbsf_super_info *sf_g);
239	extern void vbsf_update_inode(struct inode pInode, struct vbsf_inode_info pInodeInfo, PSHFLFSOBJINFO pObjInfo,
240	struct vbsf_super_info *sf_g, bool fInodeLocked);
241	extern int vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced, bool fInodeLocked);
242	extern int vbsf_inode_revalidate_with_handle(struct dentry *dentry, SHFLHANDLE hHostFile, bool fForced, bool fInodeLocked);
243	#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 18)
244	# if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
245	extern int vbsf_inode_getattr(const struct path path, struct kstat kstat, u32 request_mask, unsigned int query_flags);
246	# else
247	extern int vbsf_inode_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *kstat);
248	# endif
249	#else /* < 2.5.44 */
250	extern int vbsf_inode_revalidate(struct dentry *dentry);
251	#endif /* < 2.5.44 */
252	extern int vbsf_inode_setattr(struct dentry dentry, struct iattr iattr);
253
254
255	extern void vbsf_handle_drop_chain(struct vbsf_inode_info *pInodeInfo);
256	extern struct vbsf_handle vbsf_handle_find(struct vbsf_inode_info pInodeInfo, uint32_t fFlagsSet, uint32_t fFlagsClear);
257	extern uint32_t vbsf_handle_release_slow(struct vbsf_handle pHandle, struct vbsf_super_info sf_g, const char *pszCaller);
258	extern void vbsf_handle_append(struct vbsf_inode_info pInodeInfo, struct vbsf_handle pHandle);
259
260	/**
261	* Releases a handle.
262	*
263	* @returns New reference count.
264	* @param pHandle The handle to release.
265	* @param sf_g The info structure for the shared folder associated
266	* with the handle.
267	* @param pszCaller The caller name (for logging failures).
268	*/
269	DECLINLINE(uint32_t) vbsf_handle_release(struct vbsf_handle pHandle, struct vbsf_super_info sf_g, const char *pszCaller)
270	{
271	uint32_t cRefs;
272
273	Assert((pHandle->fFlags & VBSF_HANDLE_F_MAGIC_MASK) == VBSF_HANDLE_F_MAGIC);
274	Assert(pHandle->pInodeInfo);
275	Assert(pHandle->pInodeInfo && pHandle->pInodeInfo->u32Magic == SF_INODE_INFO_MAGIC);
276
277	cRefs = ASMAtomicDecU32(&pHandle->cRefs);
278	Assert(cRefs < _64M);
279	if (cRefs)
280	return cRefs;
281	return vbsf_handle_release_slow(pHandle, sf_g, pszCaller);
282	}
283
284
285	/**
286	* VBox specific information for a regular file.
287	*/
288	struct vbsf_reg_info {
289	/** Handle tracking structure.
290	* @note Must be first! */
291	struct vbsf_handle Handle;
292	};
293
294	uint32_t vbsf_linux_oflags_to_vbox(unsigned fLnxOpen, uint32_t pfHandle, const char pszCaller);
295
296
297	/**
298	* VBox specific information for an open directory.
299	*/
300	struct vbsf_dir_info {
301	/** Handle tracking structure.
302	* @note Must be first! */
303	struct vbsf_handle Handle;
304	/** Semaphore protecting everything below. */
305	struct semaphore Lock;
306	/** A magic number (VBSF_DIR_INFO_MAGIC). */
307	uint32_t u32Magic;
308	/** Size of the buffer for directory entries. */
309	uint32_t cbBuf;
310	/** Buffer for directory entries on the physical heap. */
311	PSHFLDIRINFO pBuf;
312	/** Number of valid bytes in the buffer. */
313	uint32_t cbValid;
314	/** Number of entries left in the buffer. */
315	uint32_t cEntriesLeft;
316	/** The position of the next entry. Incremented by one for each entry. */
317	loff_t offPos;
318	/** The next entry. */
319	PSHFLDIRINFO pEntry;
320	/** Set if there are no more files. */
321	bool fNoMoreFiles;
322	};
323
324	/** Magic number for vbsf_dir_info::u32Magic (Robert Anson Heinlein). */
325	#define VBSF_DIR_INFO_MAGIC UINT32_C(0x19070707)
326	/** Value of vbsf_dir_info::u32Magic when freed. */
327	#define VBSF_DIR_INFO_MAGIC_DEAD UINT32_C(0x19880508)
328
329
330	/**
331	* Sets the update-jiffies value for a dentry.
332	*
333	* This is used together with vbsf_super_info::ttl to reduce re-validation of
334	* dentry structures while walking.
335	*
336	* This used to be living in d_time, but since 4.9.0 that seems to have become
337	* unfashionable and d_fsdata is now used to for this purpose. We do this all
338	* the way back, since d_time seems only to have been used by the file system
339	* specific code (at least going back to 2.4.0).
340	*/
341	DECLINLINE(void) vbsf_dentry_set_update_jiffies(struct dentry *pDirEntry, unsigned long uToSet)
342	{
343	/SFLOG3(("vbsf_dentry_set_update_jiffies: %p: %lx -> %#lx\n", pDirEntry, (unsigned long)pDirEntry->d_fsdata, uToSet));/
344	pDirEntry->d_fsdata = (void *)uToSet;
345	}
346
347	/**
348	* Get the update-jiffies value for a dentry.
349	*/
350	DECLINLINE(unsigned long) vbsf_dentry_get_update_jiffies(struct dentry *pDirEntry)
351	{
352	return (unsigned long)pDirEntry->d_fsdata;
353	}
354
355	/**
356	* Increase the time-to-live of @a pDirEntry and all ancestors.
357	* @param pDirEntry The directory entry cache entry which ancestors
358	* we should increase the TTL for.
359	*/
360	DECLINLINE(void) vbsf_dentry_chain_increase_ttl(struct dentry *pDirEntry)
361	{
362	#ifdef VBOX_STRICT
363	struct super_block * const pSuper = pDirEntry->d_sb;
364	#endif
365	unsigned long const uToSet = jiffies;
366	do {
367	Assert(pDirEntry->d_sb == pSuper);
368	vbsf_dentry_set_update_jiffies(pDirEntry, uToSet);
369	pDirEntry = pDirEntry->d_parent;
370	} while (!IS_ROOT(pDirEntry));
371	}
372
373	/**
374	* Increase the time-to-live of all ancestors.
375	* @param pDirEntry The directory entry cache entry which ancestors
376	* we should increase the TTL for.
377	*/
378	DECLINLINE(void) vbsf_dentry_chain_increase_parent_ttl(struct dentry *pDirEntry)
379	{
380	Assert(!pDirEntry->d_parent \|\| pDirEntry->d_parent->d_sb == pDirEntry->d_sb);
381	pDirEntry = pDirEntry->d_parent;
382	if (pDirEntry)
383	vbsf_dentry_chain_increase_ttl(pDirEntry);
384	}
385
386	/** Macro for getting the dentry for a struct file. */
387	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
388	# define VBSF_GET_F_DENTRY(f) file_dentry(f)
389	#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
390	# define VBSF_GET_F_DENTRY(f) (f->f_path.dentry)
391	#else
392	# define VBSF_GET_F_DENTRY(f) (f->f_dentry)
393	#endif
394
395	extern int vbsf_stat(const char caller, struct vbsf_super_info sf_g, SHFLSTRING * path, PSHFLFSOBJINFO result, int ok_to_fail);
396	extern int vbsf_path_from_dentry(struct vbsf_super_info sf_g, struct vbsf_inode_info sf_i, struct dentry *dentry,
397	SHFLSTRING ** result, const char *caller);
398	extern int vbsf_nlscpy(struct vbsf_super_info sf_g, char name, size_t name_bound_len,
399	const unsigned char *utf8_name, size_t utf8_len);
400	extern int vbsf_nls_to_shflstring(struct vbsf_super_info sf_g, const char pszNls, PSHFLSTRING *ppString);
401
402
403	/**
404	* Converts Linux access permissions to VBox ones (mode & 0777).
405	*
406	* @note Currently identical.
407	* @sa sf_access_permissions_to_linux
408	*/
409	DECLINLINE(uint32_t) sf_access_permissions_to_vbox(int fAttr)
410	{
411	/* Access bits should be the same: */
412	AssertCompile(RTFS_UNIX_IRUSR == S_IRUSR);
413	AssertCompile(RTFS_UNIX_IWUSR == S_IWUSR);
414	AssertCompile(RTFS_UNIX_IXUSR == S_IXUSR);
415	AssertCompile(RTFS_UNIX_IRGRP == S_IRGRP);
416	AssertCompile(RTFS_UNIX_IWGRP == S_IWGRP);
417	AssertCompile(RTFS_UNIX_IXGRP == S_IXGRP);
418	AssertCompile(RTFS_UNIX_IROTH == S_IROTH);
419	AssertCompile(RTFS_UNIX_IWOTH == S_IWOTH);
420	AssertCompile(RTFS_UNIX_IXOTH == S_IXOTH);
421
422	return fAttr & RTFS_UNIX_ALL_ACCESS_PERMS;
423	}
424
425	#endif /* !GA_INCLUDED_SRC_linux_sharedfolders_vfsmod_h */

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source: vbox/trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.h@ 77858

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