xref: /haiku/src/add-ons/kernel/file_systems/exfat/Inode.cpp (revision 837b16251d4b2b6249ebcaa19bb319cbe82c6126)
1 /*
2  * Copyright 2011, Jérôme Duval, korli@users.berlios.de.
3  * Copyright 2008, Axel Dörfler, axeld@pinc-software.de.
4  * This file may be used under the terms of the MIT License.
5  */
6 
7 
8 #include "Inode.h"
9 
10 #include <real_time_clock.h>
11 #include <string.h>
12 #include <stdlib.h>
13 
14 #include "CachedBlock.h"
15 #include "DataStream.h"
16 #include "Utility.h"
17 
18 
19 #undef ASSERT
20 //#define TRACE_EXFAT
21 #ifdef TRACE_EXFAT
22 #	define TRACE(x...) dprintf("\33[34mexfat:\33[0m " x)
23 #	define ASSERT(x) { if (!(x)) kernel_debugger("exfat: assert failed: " #x "\n"); }
24 #else
25 #	define TRACE(x...) ;
26 #	define ASSERT(x) ;
27 #endif
28 #define ERROR(x...) dprintf("\33[34mexfat:\33[0m " x)
29 
30 
31 Inode::Inode(Volume* volume, cluster_t cluster, uint32 offset)
32 	:
33 	fVolume(volume),
34 	fID(volume->GetIno(cluster, offset, 0)),
35 	fCluster(cluster),
36 	fOffset(offset),
37 	fCache(NULL),
38 	fMap(NULL)
39 {
40 	TRACE("Inode::Inode(%ld, %d) inode %" B_PRIdINO "\n", Cluster(), Offset(),
41 		ID());
42 	_Init();
43 
44 	if (ID() == 1) {
45 		fFileEntry.file.SetAttribs(EXFAT_ENTRY_ATTRIB_SUBDIR);
46 		fFileEntry.file_info.SetStartCluster(Cluster());
47 		fFileInfoEntry.file_info.SetFlag(0);
48 	} else {
49 		fInitStatus = UpdateNodeFromDisk();
50 		if (fInitStatus == B_OK && !IsDirectory() && !IsSymLink()) {
51 			fCache = file_cache_create(fVolume->ID(), ID(), Size());
52 			fMap = file_map_create(fVolume->ID(), ID(), Size());
53 		}
54 	}
55 	TRACE("Inode::Inode(%" B_PRIdINO ") end\n", ID());
56 }
57 
58 
59 Inode::Inode(Volume* volume, ino_t ino)
60 	:
61 	fVolume(volume),
62 	fID(ino),
63 	fCluster(0),
64 	fOffset(0),
65 	fCache(NULL),
66 	fMap(NULL),
67 	fInitStatus(B_NO_INIT)
68 {
69 	struct node_key *key = volume->GetNode(ino, fParent);
70 	if (key != NULL) {
71 		fCluster = key->cluster;
72 		fOffset = key->offset;
73 		fInitStatus = B_OK;
74 	}
75 	TRACE("Inode::Inode(%" B_PRIdINO ") cluster %ld\n", ID(), Cluster());
76 	_Init();
77 
78 	if (fInitStatus == B_OK && ID() != 1) {
79 		fInitStatus = UpdateNodeFromDisk();
80 		if (!IsDirectory() && !IsSymLink()) {
81 			fCache = file_cache_create(fVolume->ID(), ID(), Size());
82 			fMap = file_map_create(fVolume->ID(), ID(), Size());
83 		}
84 	} else if (fInitStatus == B_OK && ID() == 1) {
85 		fFileEntry.file.SetAttribs(EXFAT_ENTRY_ATTRIB_SUBDIR);
86 		fFileInfoEntry.file_info.SetStartCluster(Cluster());
87 		fFileInfoEntry.file_info.SetFlag(0);
88 	}
89 }
90 
91 
92 Inode::Inode(Volume* volume)
93 	:
94 	fVolume(volume),
95 	fID(0),
96 	fCache(NULL),
97 	fMap(NULL),
98 	fInitStatus(B_NO_INIT)
99 {
100 	_Init();
101 }
102 
103 
104 Inode::~Inode()
105 {
106 	TRACE("Inode destructor\n");
107 	file_cache_delete(FileCache());
108 	file_map_delete(Map());
109 	TRACE("Inode destructor: Done\n");
110 }
111 
112 
113 status_t
114 Inode::InitCheck()
115 {
116 	return fInitStatus;
117 }
118 
119 
120 status_t
121 Inode::UpdateNodeFromDisk()
122 {
123 	DirectoryIterator iterator(this);
124 	iterator.LookupEntry(this);
125 	return B_OK;
126 }
127 
128 
129 cluster_t
130 Inode::NextCluster(cluster_t cluster) const
131 {
132 	if (!IsContiguous() || IsDirectory())
133 		return GetVolume()->NextCluster(cluster);
134 	return cluster + 1;
135 }
136 
137 
138 mode_t
139 Inode::Mode() const
140 {
141 	mode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
142 	if (!fVolume->IsReadOnly())
143 		mode |= S_IWUSR | S_IWGRP | S_IWOTH;
144 	if (fFileEntry.file.Attribs() & EXFAT_ENTRY_ATTRIB_SUBDIR)
145 		mode |= S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH;
146 	else
147 		mode |= S_IFREG;
148 	return mode;
149 }
150 
151 
152 status_t
153 Inode::CheckPermissions(int accessMode) const
154 {
155 	// you never have write access to a read-only volume
156 	if ((accessMode & W_OK) != 0 && fVolume->IsReadOnly())
157 		return B_READ_ONLY_DEVICE;
158 
159 	// get node permissions
160 	mode_t mode = Mode();
161 	int userPermissions = (mode & S_IRWXU) >> 6;
162 	int groupPermissions = (mode & S_IRWXG) >> 3;
163 	int otherPermissions = mode & S_IRWXO;
164 
165 	// get the node permissions for this uid/gid
166 	int permissions = 0;
167 	uid_t uid = geteuid();
168 	gid_t gid = getegid();
169 
170 	if (uid == 0) {
171 		// user is root
172 		// root has always read/write permission, but at least one of the
173 		// X bits must be set for execute permission
174 		permissions = userPermissions | groupPermissions | otherPermissions
175 			| R_OK | W_OK;
176 	} else if (uid == (uid_t)UserID()) {
177 		// user is node owner
178 		permissions = userPermissions;
179 	} else if (gid == (gid_t)GroupID()) {
180 		// user is in owning group
181 		permissions = groupPermissions;
182 	} else {
183 		// user is one of the others
184 		permissions = otherPermissions;
185 	}
186 
187 	return (accessMode & ~permissions) == 0 ? B_OK : B_NOT_ALLOWED;
188 	return B_OK;
189 }
190 
191 
192 status_t
193 Inode::FindBlock(off_t pos, off_t& physical, off_t *_length)
194 {
195 	DataStream stream(fVolume, this, Size());
196 	return stream.FindBlock(pos, physical, _length);
197 }
198 
199 
200 status_t
201 Inode::ReadAt(off_t pos, uint8* buffer, size_t* _length)
202 {
203 	size_t length = *_length;
204 
205 	// set/check boundaries for pos/length
206 	if (pos < 0) {
207 		ERROR("inode %" B_PRIdINO ": ReadAt failed(pos %lld, length %lu)\n",
208 			ID(), pos, length);
209 		return B_BAD_VALUE;
210 	}
211 
212 	if (pos >= Size() || length == 0) {
213 		TRACE("inode %" B_PRIdINO ": ReadAt 0 (pos %lld, length %lu)\n",
214 			ID(), pos, length);
215 		*_length = 0;
216 		return B_NO_ERROR;
217 	}
218 
219 	return file_cache_read(FileCache(), NULL, pos, buffer, _length);
220 }
221 
222 
223 bool
224 Inode::VisitFile(struct exfat_entry* entry)
225 {
226 	fFileEntry = *entry;
227 	return false;
228 }
229 
230 
231 bool
232 Inode::VisitFileInfo(struct exfat_entry* entry)
233 {
234 	fFileInfoEntry = *entry;
235 	return false;
236 }
237 
238 
239 void
240 Inode::_Init()
241 {
242 	memset(&fFileEntry, 0, sizeof(fFileEntry));
243 	memset(&fFileInfoEntry, 0, sizeof(fFileInfoEntry));
244 	rw_lock_init(&fLock, "exfat inode");
245 }
246 
247 
248 // If divisible by 4, but not divisible by 100, but divisible by 400, it's a leap year
249 // 1996 is leap, 1900 is not, 2000 is, 2100 is not
250 #define IS_LEAP_YEAR(y) ((((y) % 4) == 0) && (((y) % 100) || ((((y)) % 400) == 0)))
251 
252 /* returns leap days since 1970 */
253 static int leaps(int yr, int mon)
254 {
255 	// yr is 1970-based, mon 0-based
256 	int result = (yr+2)/4 - (yr + 70) / 100;
257 	if((yr+70) >= 100) result++; // correct for 2000
258 	if (IS_LEAP_YEAR(yr + 1970))
259 		if (mon < 2) result--;
260 	return result;
261 }
262 
263 static int daze[] = { 0,0,31,59,90,120,151,181,212,243,273,304,334,0,0,0 };
264 
265 void
266 Inode::_GetTimespec(uint16 date, uint16 time, struct timespec &timespec) const
267 {
268 	static int32 tzoffset = -1; /* in minutes */
269 	if (tzoffset == -1)
270 		tzoffset = get_timezone_offset() / 60;
271 
272 	time_t days = daze[(date>>5)&15] + ((date>>9)+10)*365 + leaps((date>>9)+10,((date>>5)&15)-1)+(date&31)-1;
273 
274 	timespec.tv_sec = ((days * 24 + (time >> 11)) * 60 + ((time>>5)&63) + tzoffset) * 60 + 2*(time&31);
275 	timespec.tv_nsec = 0;
276 }
277 
278 
279