xref: /openbmc/linux/fs/ntfs/layout.h (revision 9b93eb47)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * layout.h - All NTFS associated on-disk structures. Part of the Linux-NTFS
4  *	      project.
5  *
6  * Copyright (c) 2001-2005 Anton Altaparmakov
7  * Copyright (c) 2002 Richard Russon
8  */
9 
10 #ifndef _LINUX_NTFS_LAYOUT_H
11 #define _LINUX_NTFS_LAYOUT_H
12 
13 #include <linux/types.h>
14 #include <linux/bitops.h>
15 #include <linux/list.h>
16 #include <asm/byteorder.h>
17 
18 #include "types.h"
19 
20 /* The NTFS oem_id "NTFS    " */
21 #define magicNTFS	cpu_to_le64(0x202020205346544eULL)
22 
23 /*
24  * Location of bootsector on partition:
25  *	The standard NTFS_BOOT_SECTOR is on sector 0 of the partition.
26  *	On NT4 and above there is one backup copy of the boot sector to
27  *	be found on the last sector of the partition (not normally accessible
28  *	from within Windows as the bootsector contained number of sectors
29  *	value is one less than the actual value!).
30  *	On versions of NT 3.51 and earlier, the backup copy was located at
31  *	number of sectors/2 (integer divide), i.e. in the middle of the volume.
32  */
33 
34 /*
35  * BIOS parameter block (bpb) structure.
36  */
37 typedef struct {
38 	le16 bytes_per_sector;		/* Size of a sector in bytes. */
39 	u8  sectors_per_cluster;	/* Size of a cluster in sectors. */
40 	le16 reserved_sectors;		/* zero */
41 	u8  fats;			/* zero */
42 	le16 root_entries;		/* zero */
43 	le16 sectors;			/* zero */
44 	u8  media_type;			/* 0xf8 = hard disk */
45 	le16 sectors_per_fat;		/* zero */
46 	le16 sectors_per_track;		/* irrelevant */
47 	le16 heads;			/* irrelevant */
48 	le32 hidden_sectors;		/* zero */
49 	le32 large_sectors;		/* zero */
50 } __attribute__ ((__packed__)) BIOS_PARAMETER_BLOCK;
51 
52 /*
53  * NTFS boot sector structure.
54  */
55 typedef struct {
56 	u8  jump[3];			/* Irrelevant (jump to boot up code).*/
57 	le64 oem_id;			/* Magic "NTFS    ". */
58 	BIOS_PARAMETER_BLOCK bpb;	/* See BIOS_PARAMETER_BLOCK. */
59 	u8  unused[4];			/* zero, NTFS diskedit.exe states that
60 					   this is actually:
61 						__u8 physical_drive;	// 0x80
62 						__u8 current_head;	// zero
63 						__u8 extended_boot_signature;
64 									// 0x80
65 						__u8 unused;		// zero
66 					 */
67 /*0x28*/sle64 number_of_sectors;	/* Number of sectors in volume. Gives
68 					   maximum volume size of 2^63 sectors.
69 					   Assuming standard sector size of 512
70 					   bytes, the maximum byte size is
71 					   approx. 4.7x10^21 bytes. (-; */
72 	sle64 mft_lcn;			/* Cluster location of mft data. */
73 	sle64 mftmirr_lcn;		/* Cluster location of copy of mft. */
74 	s8  clusters_per_mft_record;	/* Mft record size in clusters. */
75 	u8  reserved0[3];		/* zero */
76 	s8  clusters_per_index_record;	/* Index block size in clusters. */
77 	u8  reserved1[3];		/* zero */
78 	le64 volume_serial_number;	/* Irrelevant (serial number). */
79 	le32 checksum;			/* Boot sector checksum. */
80 /*0x54*/u8  bootstrap[426];		/* Irrelevant (boot up code). */
81 	le16 end_of_sector_marker;	/* End of bootsector magic. Always is
82 					   0xaa55 in little endian. */
83 /* sizeof() = 512 (0x200) bytes */
84 } __attribute__ ((__packed__)) NTFS_BOOT_SECTOR;
85 
86 /*
87  * Magic identifiers present at the beginning of all ntfs record containing
88  * records (like mft records for example).
89  */
90 enum {
91 	/* Found in $MFT/$DATA. */
92 	magic_FILE = cpu_to_le32(0x454c4946), /* Mft entry. */
93 	magic_INDX = cpu_to_le32(0x58444e49), /* Index buffer. */
94 	magic_HOLE = cpu_to_le32(0x454c4f48), /* ? (NTFS 3.0+?) */
95 
96 	/* Found in $LogFile/$DATA. */
97 	magic_RSTR = cpu_to_le32(0x52545352), /* Restart page. */
98 	magic_RCRD = cpu_to_le32(0x44524352), /* Log record page. */
99 
100 	/* Found in $LogFile/$DATA.  (May be found in $MFT/$DATA, also?) */
101 	magic_CHKD = cpu_to_le32(0x444b4843), /* Modified by chkdsk. */
102 
103 	/* Found in all ntfs record containing records. */
104 	magic_BAAD = cpu_to_le32(0x44414142), /* Failed multi sector
105 						       transfer was detected. */
106 	/*
107 	 * Found in $LogFile/$DATA when a page is full of 0xff bytes and is
108 	 * thus not initialized.  Page must be initialized before using it.
109 	 */
110 	magic_empty = cpu_to_le32(0xffffffff) /* Record is empty. */
111 };
112 
113 typedef le32 NTFS_RECORD_TYPE;
114 
115 /*
116  * Generic magic comparison macros. Finally found a use for the ## preprocessor
117  * operator! (-8
118  */
119 
120 static inline bool __ntfs_is_magic(le32 x, NTFS_RECORD_TYPE r)
121 {
122 	return (x == r);
123 }
124 #define ntfs_is_magic(x, m)	__ntfs_is_magic(x, magic_##m)
125 
126 static inline bool __ntfs_is_magicp(le32 *p, NTFS_RECORD_TYPE r)
127 {
128 	return (*p == r);
129 }
130 #define ntfs_is_magicp(p, m)	__ntfs_is_magicp(p, magic_##m)
131 
132 /*
133  * Specialised magic comparison macros for the NTFS_RECORD_TYPEs defined above.
134  */
135 #define ntfs_is_file_record(x)		( ntfs_is_magic (x, FILE) )
136 #define ntfs_is_file_recordp(p)		( ntfs_is_magicp(p, FILE) )
137 #define ntfs_is_mft_record(x)		( ntfs_is_file_record (x) )
138 #define ntfs_is_mft_recordp(p)		( ntfs_is_file_recordp(p) )
139 #define ntfs_is_indx_record(x)		( ntfs_is_magic (x, INDX) )
140 #define ntfs_is_indx_recordp(p)		( ntfs_is_magicp(p, INDX) )
141 #define ntfs_is_hole_record(x)		( ntfs_is_magic (x, HOLE) )
142 #define ntfs_is_hole_recordp(p)		( ntfs_is_magicp(p, HOLE) )
143 
144 #define ntfs_is_rstr_record(x)		( ntfs_is_magic (x, RSTR) )
145 #define ntfs_is_rstr_recordp(p)		( ntfs_is_magicp(p, RSTR) )
146 #define ntfs_is_rcrd_record(x)		( ntfs_is_magic (x, RCRD) )
147 #define ntfs_is_rcrd_recordp(p)		( ntfs_is_magicp(p, RCRD) )
148 
149 #define ntfs_is_chkd_record(x)		( ntfs_is_magic (x, CHKD) )
150 #define ntfs_is_chkd_recordp(p)		( ntfs_is_magicp(p, CHKD) )
151 
152 #define ntfs_is_baad_record(x)		( ntfs_is_magic (x, BAAD) )
153 #define ntfs_is_baad_recordp(p)		( ntfs_is_magicp(p, BAAD) )
154 
155 #define ntfs_is_empty_record(x)		( ntfs_is_magic (x, empty) )
156 #define ntfs_is_empty_recordp(p)	( ntfs_is_magicp(p, empty) )
157 
158 /*
159  * The Update Sequence Array (usa) is an array of the le16 values which belong
160  * to the end of each sector protected by the update sequence record in which
161  * this array is contained. Note that the first entry is the Update Sequence
162  * Number (usn), a cyclic counter of how many times the protected record has
163  * been written to disk. The values 0 and -1 (ie. 0xffff) are not used. All
164  * last le16's of each sector have to be equal to the usn (during reading) or
165  * are set to it (during writing). If they are not, an incomplete multi sector
166  * transfer has occurred when the data was written.
167  * The maximum size for the update sequence array is fixed to:
168  *	maximum size = usa_ofs + (usa_count * 2) = 510 bytes
169  * The 510 bytes comes from the fact that the last le16 in the array has to
170  * (obviously) finish before the last le16 of the first 512-byte sector.
171  * This formula can be used as a consistency check in that usa_ofs +
172  * (usa_count * 2) has to be less than or equal to 510.
173  */
174 typedef struct {
175 	NTFS_RECORD_TYPE magic;	/* A four-byte magic identifying the record
176 				   type and/or status. */
177 	le16 usa_ofs;		/* Offset to the Update Sequence Array (usa)
178 				   from the start of the ntfs record. */
179 	le16 usa_count;		/* Number of le16 sized entries in the usa
180 				   including the Update Sequence Number (usn),
181 				   thus the number of fixups is the usa_count
182 				   minus 1. */
183 } __attribute__ ((__packed__)) NTFS_RECORD;
184 
185 /*
186  * System files mft record numbers. All these files are always marked as used
187  * in the bitmap attribute of the mft; presumably in order to avoid accidental
188  * allocation for random other mft records. Also, the sequence number for each
189  * of the system files is always equal to their mft record number and it is
190  * never modified.
191  */
192 typedef enum {
193 	FILE_MFT       = 0,	/* Master file table (mft). Data attribute
194 				   contains the entries and bitmap attribute
195 				   records which ones are in use (bit==1). */
196 	FILE_MFTMirr   = 1,	/* Mft mirror: copy of first four mft records
197 				   in data attribute. If cluster size > 4kiB,
198 				   copy of first N mft records, with
199 					N = cluster_size / mft_record_size. */
200 	FILE_LogFile   = 2,	/* Journalling log in data attribute. */
201 	FILE_Volume    = 3,	/* Volume name attribute and volume information
202 				   attribute (flags and ntfs version). Windows
203 				   refers to this file as volume DASD (Direct
204 				   Access Storage Device). */
205 	FILE_AttrDef   = 4,	/* Array of attribute definitions in data
206 				   attribute. */
207 	FILE_root      = 5,	/* Root directory. */
208 	FILE_Bitmap    = 6,	/* Allocation bitmap of all clusters (lcns) in
209 				   data attribute. */
210 	FILE_Boot      = 7,	/* Boot sector (always at cluster 0) in data
211 				   attribute. */
212 	FILE_BadClus   = 8,	/* Contains all bad clusters in the non-resident
213 				   data attribute. */
214 	FILE_Secure    = 9,	/* Shared security descriptors in data attribute
215 				   and two indexes into the descriptors.
216 				   Appeared in Windows 2000. Before that, this
217 				   file was named $Quota but was unused. */
218 	FILE_UpCase    = 10,	/* Uppercase equivalents of all 65536 Unicode
219 				   characters in data attribute. */
220 	FILE_Extend    = 11,	/* Directory containing other system files (eg.
221 				   $ObjId, $Quota, $Reparse and $UsnJrnl). This
222 				   is new to NTFS3.0. */
223 	FILE_reserved12 = 12,	/* Reserved for future use (records 12-15). */
224 	FILE_reserved13 = 13,
225 	FILE_reserved14 = 14,
226 	FILE_reserved15 = 15,
227 	FILE_first_user = 16,	/* First user file, used as test limit for
228 				   whether to allow opening a file or not. */
229 } NTFS_SYSTEM_FILES;
230 
231 /*
232  * These are the so far known MFT_RECORD_* flags (16-bit) which contain
233  * information about the mft record in which they are present.
234  */
235 enum {
236 	MFT_RECORD_IN_USE	= cpu_to_le16(0x0001),
237 	MFT_RECORD_IS_DIRECTORY = cpu_to_le16(0x0002),
238 } __attribute__ ((__packed__));
239 
240 typedef le16 MFT_RECORD_FLAGS;
241 
242 /*
243  * mft references (aka file references or file record segment references) are
244  * used whenever a structure needs to refer to a record in the mft.
245  *
246  * A reference consists of a 48-bit index into the mft and a 16-bit sequence
247  * number used to detect stale references.
248  *
249  * For error reporting purposes we treat the 48-bit index as a signed quantity.
250  *
251  * The sequence number is a circular counter (skipping 0) describing how many
252  * times the referenced mft record has been (re)used. This has to match the
253  * sequence number of the mft record being referenced, otherwise the reference
254  * is considered stale and removed (FIXME: only ntfsck or the driver itself?).
255  *
256  * If the sequence number is zero it is assumed that no sequence number
257  * consistency checking should be performed.
258  *
259  * FIXME: Since inodes are 32-bit as of now, the driver needs to always check
260  * for high_part being 0 and if not either BUG(), cause a panic() or handle
261  * the situation in some other way. This shouldn't be a problem as a volume has
262  * to become HUGE in order to need more than 32-bits worth of mft records.
263  * Assuming the standard mft record size of 1kb only the records (never mind
264  * the non-resident attributes, etc.) would require 4Tb of space on their own
265  * for the first 32 bits worth of records. This is only if some strange person
266  * doesn't decide to foul play and make the mft sparse which would be a really
267  * horrible thing to do as it would trash our current driver implementation. )-:
268  * Do I hear screams "we want 64-bit inodes!" ?!? (-;
269  *
270  * FIXME: The mft zone is defined as the first 12% of the volume. This space is
271  * reserved so that the mft can grow contiguously and hence doesn't become
272  * fragmented. Volume free space includes the empty part of the mft zone and
273  * when the volume's free 88% are used up, the mft zone is shrunk by a factor
274  * of 2, thus making more space available for more files/data. This process is
275  * repeated every time there is no more free space except for the mft zone until
276  * there really is no more free space.
277  */
278 
279 /*
280  * Typedef the MFT_REF as a 64-bit value for easier handling.
281  * Also define two unpacking macros to get to the reference (MREF) and
282  * sequence number (MSEQNO) respectively.
283  * The _LE versions are to be applied on little endian MFT_REFs.
284  * Note: The _LE versions will return a CPU endian formatted value!
285  */
286 #define MFT_REF_MASK_CPU 0x0000ffffffffffffULL
287 #define MFT_REF_MASK_LE cpu_to_le64(MFT_REF_MASK_CPU)
288 
289 typedef u64 MFT_REF;
290 typedef le64 leMFT_REF;
291 
292 #define MK_MREF(m, s)	((MFT_REF)(((MFT_REF)(s) << 48) |		\
293 					((MFT_REF)(m) & MFT_REF_MASK_CPU)))
294 #define MK_LE_MREF(m, s) cpu_to_le64(MK_MREF(m, s))
295 
296 #define MREF(x)		((unsigned long)((x) & MFT_REF_MASK_CPU))
297 #define MSEQNO(x)	((u16)(((x) >> 48) & 0xffff))
298 #define MREF_LE(x)	((unsigned long)(le64_to_cpu(x) & MFT_REF_MASK_CPU))
299 #define MSEQNO_LE(x)	((u16)((le64_to_cpu(x) >> 48) & 0xffff))
300 
301 #define IS_ERR_MREF(x)	(((x) & 0x0000800000000000ULL) ? true : false)
302 #define ERR_MREF(x)	((u64)((s64)(x)))
303 #define MREF_ERR(x)	((int)((s64)(x)))
304 
305 /*
306  * The mft record header present at the beginning of every record in the mft.
307  * This is followed by a sequence of variable length attribute records which
308  * is terminated by an attribute of type AT_END which is a truncated attribute
309  * in that it only consists of the attribute type code AT_END and none of the
310  * other members of the attribute structure are present.
311  */
312 typedef struct {
313 /*Ofs*/
314 /*  0	NTFS_RECORD; -- Unfolded here as gcc doesn't like unnamed structs. */
315 	NTFS_RECORD_TYPE magic;	/* Usually the magic is "FILE". */
316 	le16 usa_ofs;		/* See NTFS_RECORD definition above. */
317 	le16 usa_count;		/* See NTFS_RECORD definition above. */
318 
319 /*  8*/	le64 lsn;		/* $LogFile sequence number for this record.
320 				   Changed every time the record is modified. */
321 /* 16*/	le16 sequence_number;	/* Number of times this mft record has been
322 				   reused. (See description for MFT_REF
323 				   above.) NOTE: The increment (skipping zero)
324 				   is done when the file is deleted. NOTE: If
325 				   this is zero it is left zero. */
326 /* 18*/	le16 link_count;	/* Number of hard links, i.e. the number of
327 				   directory entries referencing this record.
328 				   NOTE: Only used in mft base records.
329 				   NOTE: When deleting a directory entry we
330 				   check the link_count and if it is 1 we
331 				   delete the file. Otherwise we delete the
332 				   FILE_NAME_ATTR being referenced by the
333 				   directory entry from the mft record and
334 				   decrement the link_count.
335 				   FIXME: Careful with Win32 + DOS names! */
336 /* 20*/	le16 attrs_offset;	/* Byte offset to the first attribute in this
337 				   mft record from the start of the mft record.
338 				   NOTE: Must be aligned to 8-byte boundary. */
339 /* 22*/	MFT_RECORD_FLAGS flags;	/* Bit array of MFT_RECORD_FLAGS. When a file
340 				   is deleted, the MFT_RECORD_IN_USE flag is
341 				   set to zero. */
342 /* 24*/	le32 bytes_in_use;	/* Number of bytes used in this mft record.
343 				   NOTE: Must be aligned to 8-byte boundary. */
344 /* 28*/	le32 bytes_allocated;	/* Number of bytes allocated for this mft
345 				   record. This should be equal to the mft
346 				   record size. */
347 /* 32*/	leMFT_REF base_mft_record;/* This is zero for base mft records.
348 				   When it is not zero it is a mft reference
349 				   pointing to the base mft record to which
350 				   this record belongs (this is then used to
351 				   locate the attribute list attribute present
352 				   in the base record which describes this
353 				   extension record and hence might need
354 				   modification when the extension record
355 				   itself is modified, also locating the
356 				   attribute list also means finding the other
357 				   potential extents, belonging to the non-base
358 				   mft record). */
359 /* 40*/	le16 next_attr_instance;/* The instance number that will be assigned to
360 				   the next attribute added to this mft record.
361 				   NOTE: Incremented each time after it is used.
362 				   NOTE: Every time the mft record is reused
363 				   this number is set to zero.  NOTE: The first
364 				   instance number is always 0. */
365 /* The below fields are specific to NTFS 3.1+ (Windows XP and above): */
366 /* 42*/ le16 reserved;		/* Reserved/alignment. */
367 /* 44*/ le32 mft_record_number;	/* Number of this mft record. */
368 /* sizeof() = 48 bytes */
369 /*
370  * When (re)using the mft record, we place the update sequence array at this
371  * offset, i.e. before we start with the attributes.  This also makes sense,
372  * otherwise we could run into problems with the update sequence array
373  * containing in itself the last two bytes of a sector which would mean that
374  * multi sector transfer protection wouldn't work.  As you can't protect data
375  * by overwriting it since you then can't get it back...
376  * When reading we obviously use the data from the ntfs record header.
377  */
378 } __attribute__ ((__packed__)) MFT_RECORD;
379 
380 /* This is the version without the NTFS 3.1+ specific fields. */
381 typedef struct {
382 /*Ofs*/
383 /*  0	NTFS_RECORD; -- Unfolded here as gcc doesn't like unnamed structs. */
384 	NTFS_RECORD_TYPE magic;	/* Usually the magic is "FILE". */
385 	le16 usa_ofs;		/* See NTFS_RECORD definition above. */
386 	le16 usa_count;		/* See NTFS_RECORD definition above. */
387 
388 /*  8*/	le64 lsn;		/* $LogFile sequence number for this record.
389 				   Changed every time the record is modified. */
390 /* 16*/	le16 sequence_number;	/* Number of times this mft record has been
391 				   reused. (See description for MFT_REF
392 				   above.) NOTE: The increment (skipping zero)
393 				   is done when the file is deleted. NOTE: If
394 				   this is zero it is left zero. */
395 /* 18*/	le16 link_count;	/* Number of hard links, i.e. the number of
396 				   directory entries referencing this record.
397 				   NOTE: Only used in mft base records.
398 				   NOTE: When deleting a directory entry we
399 				   check the link_count and if it is 1 we
400 				   delete the file. Otherwise we delete the
401 				   FILE_NAME_ATTR being referenced by the
402 				   directory entry from the mft record and
403 				   decrement the link_count.
404 				   FIXME: Careful with Win32 + DOS names! */
405 /* 20*/	le16 attrs_offset;	/* Byte offset to the first attribute in this
406 				   mft record from the start of the mft record.
407 				   NOTE: Must be aligned to 8-byte boundary. */
408 /* 22*/	MFT_RECORD_FLAGS flags;	/* Bit array of MFT_RECORD_FLAGS. When a file
409 				   is deleted, the MFT_RECORD_IN_USE flag is
410 				   set to zero. */
411 /* 24*/	le32 bytes_in_use;	/* Number of bytes used in this mft record.
412 				   NOTE: Must be aligned to 8-byte boundary. */
413 /* 28*/	le32 bytes_allocated;	/* Number of bytes allocated for this mft
414 				   record. This should be equal to the mft
415 				   record size. */
416 /* 32*/	leMFT_REF base_mft_record;/* This is zero for base mft records.
417 				   When it is not zero it is a mft reference
418 				   pointing to the base mft record to which
419 				   this record belongs (this is then used to
420 				   locate the attribute list attribute present
421 				   in the base record which describes this
422 				   extension record and hence might need
423 				   modification when the extension record
424 				   itself is modified, also locating the
425 				   attribute list also means finding the other
426 				   potential extents, belonging to the non-base
427 				   mft record). */
428 /* 40*/	le16 next_attr_instance;/* The instance number that will be assigned to
429 				   the next attribute added to this mft record.
430 				   NOTE: Incremented each time after it is used.
431 				   NOTE: Every time the mft record is reused
432 				   this number is set to zero.  NOTE: The first
433 				   instance number is always 0. */
434 /* sizeof() = 42 bytes */
435 /*
436  * When (re)using the mft record, we place the update sequence array at this
437  * offset, i.e. before we start with the attributes.  This also makes sense,
438  * otherwise we could run into problems with the update sequence array
439  * containing in itself the last two bytes of a sector which would mean that
440  * multi sector transfer protection wouldn't work.  As you can't protect data
441  * by overwriting it since you then can't get it back...
442  * When reading we obviously use the data from the ntfs record header.
443  */
444 } __attribute__ ((__packed__)) MFT_RECORD_OLD;
445 
446 /*
447  * System defined attributes (32-bit).  Each attribute type has a corresponding
448  * attribute name (Unicode string of maximum 64 character length) as described
449  * by the attribute definitions present in the data attribute of the $AttrDef
450  * system file.  On NTFS 3.0 volumes the names are just as the types are named
451  * in the below defines exchanging AT_ for the dollar sign ($).  If that is not
452  * a revealing choice of symbol I do not know what is... (-;
453  */
454 enum {
455 	AT_UNUSED			= cpu_to_le32(         0),
456 	AT_STANDARD_INFORMATION		= cpu_to_le32(      0x10),
457 	AT_ATTRIBUTE_LIST		= cpu_to_le32(      0x20),
458 	AT_FILE_NAME			= cpu_to_le32(      0x30),
459 	AT_OBJECT_ID			= cpu_to_le32(      0x40),
460 	AT_SECURITY_DESCRIPTOR		= cpu_to_le32(      0x50),
461 	AT_VOLUME_NAME			= cpu_to_le32(      0x60),
462 	AT_VOLUME_INFORMATION		= cpu_to_le32(      0x70),
463 	AT_DATA				= cpu_to_le32(      0x80),
464 	AT_INDEX_ROOT			= cpu_to_le32(      0x90),
465 	AT_INDEX_ALLOCATION		= cpu_to_le32(      0xa0),
466 	AT_BITMAP			= cpu_to_le32(      0xb0),
467 	AT_REPARSE_POINT		= cpu_to_le32(      0xc0),
468 	AT_EA_INFORMATION		= cpu_to_le32(      0xd0),
469 	AT_EA				= cpu_to_le32(      0xe0),
470 	AT_PROPERTY_SET			= cpu_to_le32(      0xf0),
471 	AT_LOGGED_UTILITY_STREAM	= cpu_to_le32(     0x100),
472 	AT_FIRST_USER_DEFINED_ATTRIBUTE	= cpu_to_le32(    0x1000),
473 	AT_END				= cpu_to_le32(0xffffffff)
474 };
475 
476 typedef le32 ATTR_TYPE;
477 
478 /*
479  * The collation rules for sorting views/indexes/etc (32-bit).
480  *
481  * COLLATION_BINARY - Collate by binary compare where the first byte is most
482  *	significant.
483  * COLLATION_UNICODE_STRING - Collate Unicode strings by comparing their binary
484  *	Unicode values, except that when a character can be uppercased, the
485  *	upper case value collates before the lower case one.
486  * COLLATION_FILE_NAME - Collate file names as Unicode strings. The collation
487  *	is done very much like COLLATION_UNICODE_STRING. In fact I have no idea
488  *	what the difference is. Perhaps the difference is that file names
489  *	would treat some special characters in an odd way (see
490  *	unistr.c::ntfs_collate_names() and unistr.c::legal_ansi_char_array[]
491  *	for what I mean but COLLATION_UNICODE_STRING would not give any special
492  *	treatment to any characters at all, but this is speculation.
493  * COLLATION_NTOFS_ULONG - Sorting is done according to ascending le32 key
494  *	values. E.g. used for $SII index in FILE_Secure, which sorts by
495  *	security_id (le32).
496  * COLLATION_NTOFS_SID - Sorting is done according to ascending SID values.
497  *	E.g. used for $O index in FILE_Extend/$Quota.
498  * COLLATION_NTOFS_SECURITY_HASH - Sorting is done first by ascending hash
499  *	values and second by ascending security_id values. E.g. used for $SDH
500  *	index in FILE_Secure.
501  * COLLATION_NTOFS_ULONGS - Sorting is done according to a sequence of ascending
502  *	le32 key values. E.g. used for $O index in FILE_Extend/$ObjId, which
503  *	sorts by object_id (16-byte), by splitting up the object_id in four
504  *	le32 values and using them as individual keys. E.g. take the following
505  *	two security_ids, stored as follows on disk:
506  *		1st: a1 61 65 b7 65 7b d4 11 9e 3d 00 e0 81 10 42 59
507  *		2nd: 38 14 37 d2 d2 f3 d4 11 a5 21 c8 6b 79 b1 97 45
508  *	To compare them, they are split into four le32 values each, like so:
509  *		1st: 0xb76561a1 0x11d47b65 0xe0003d9e 0x59421081
510  *		2nd: 0xd2371438 0x11d4f3d2 0x6bc821a5 0x4597b179
511  *	Now, it is apparent why the 2nd object_id collates after the 1st: the
512  *	first le32 value of the 1st object_id is less than the first le32 of
513  *	the 2nd object_id. If the first le32 values of both object_ids were
514  *	equal then the second le32 values would be compared, etc.
515  */
516 enum {
517 	COLLATION_BINARY		= cpu_to_le32(0x00),
518 	COLLATION_FILE_NAME		= cpu_to_le32(0x01),
519 	COLLATION_UNICODE_STRING	= cpu_to_le32(0x02),
520 	COLLATION_NTOFS_ULONG		= cpu_to_le32(0x10),
521 	COLLATION_NTOFS_SID		= cpu_to_le32(0x11),
522 	COLLATION_NTOFS_SECURITY_HASH	= cpu_to_le32(0x12),
523 	COLLATION_NTOFS_ULONGS		= cpu_to_le32(0x13),
524 };
525 
526 typedef le32 COLLATION_RULE;
527 
528 /*
529  * The flags (32-bit) describing attribute properties in the attribute
530  * definition structure.  FIXME: This information is based on Regis's
531  * information and, according to him, it is not certain and probably
532  * incomplete.  The INDEXABLE flag is fairly certainly correct as only the file
533  * name attribute has this flag set and this is the only attribute indexed in
534  * NT4.
535  */
536 enum {
537 	ATTR_DEF_INDEXABLE	= cpu_to_le32(0x02), /* Attribute can be
538 					indexed. */
539 	ATTR_DEF_MULTIPLE	= cpu_to_le32(0x04), /* Attribute type
540 					can be present multiple times in the
541 					mft records of an inode. */
542 	ATTR_DEF_NOT_ZERO	= cpu_to_le32(0x08), /* Attribute value
543 					must contain at least one non-zero
544 					byte. */
545 	ATTR_DEF_INDEXED_UNIQUE	= cpu_to_le32(0x10), /* Attribute must be
546 					indexed and the attribute value must be
547 					unique for the attribute type in all of
548 					the mft records of an inode. */
549 	ATTR_DEF_NAMED_UNIQUE	= cpu_to_le32(0x20), /* Attribute must be
550 					named and the name must be unique for
551 					the attribute type in all of the mft
552 					records of an inode. */
553 	ATTR_DEF_RESIDENT	= cpu_to_le32(0x40), /* Attribute must be
554 					resident. */
555 	ATTR_DEF_ALWAYS_LOG	= cpu_to_le32(0x80), /* Always log
556 					modifications to this attribute,
557 					regardless of whether it is resident or
558 					non-resident.  Without this, only log
559 					modifications if the attribute is
560 					resident. */
561 };
562 
563 typedef le32 ATTR_DEF_FLAGS;
564 
565 /*
566  * The data attribute of FILE_AttrDef contains a sequence of attribute
567  * definitions for the NTFS volume. With this, it is supposed to be safe for an
568  * older NTFS driver to mount a volume containing a newer NTFS version without
569  * damaging it (that's the theory. In practice it's: not damaging it too much).
570  * Entries are sorted by attribute type. The flags describe whether the
571  * attribute can be resident/non-resident and possibly other things, but the
572  * actual bits are unknown.
573  */
574 typedef struct {
575 /*hex ofs*/
576 /*  0*/	ntfschar name[0x40];		/* Unicode name of the attribute. Zero
577 					   terminated. */
578 /* 80*/	ATTR_TYPE type;			/* Type of the attribute. */
579 /* 84*/	le32 display_rule;		/* Default display rule.
580 					   FIXME: What does it mean? (AIA) */
581 /* 88*/ COLLATION_RULE collation_rule;	/* Default collation rule. */
582 /* 8c*/	ATTR_DEF_FLAGS flags;		/* Flags describing the attribute. */
583 /* 90*/	sle64 min_size;			/* Optional minimum attribute size. */
584 /* 98*/	sle64 max_size;			/* Maximum size of attribute. */
585 /* sizeof() = 0xa0 or 160 bytes */
586 } __attribute__ ((__packed__)) ATTR_DEF;
587 
588 /*
589  * Attribute flags (16-bit).
590  */
591 enum {
592 	ATTR_IS_COMPRESSED    = cpu_to_le16(0x0001),
593 	ATTR_COMPRESSION_MASK = cpu_to_le16(0x00ff), /* Compression method
594 							      mask.  Also, first
595 							      illegal value. */
596 	ATTR_IS_ENCRYPTED     = cpu_to_le16(0x4000),
597 	ATTR_IS_SPARSE	      = cpu_to_le16(0x8000),
598 } __attribute__ ((__packed__));
599 
600 typedef le16 ATTR_FLAGS;
601 
602 /*
603  * Attribute compression.
604  *
605  * Only the data attribute is ever compressed in the current ntfs driver in
606  * Windows. Further, compression is only applied when the data attribute is
607  * non-resident. Finally, to use compression, the maximum allowed cluster size
608  * on a volume is 4kib.
609  *
610  * The compression method is based on independently compressing blocks of X
611  * clusters, where X is determined from the compression_unit value found in the
612  * non-resident attribute record header (more precisely: X = 2^compression_unit
613  * clusters). On Windows NT/2k, X always is 16 clusters (compression_unit = 4).
614  *
615  * There are three different cases of how a compression block of X clusters
616  * can be stored:
617  *
618  *   1) The data in the block is all zero (a sparse block):
619  *	  This is stored as a sparse block in the runlist, i.e. the runlist
620  *	  entry has length = X and lcn = -1. The mapping pairs array actually
621  *	  uses a delta_lcn value length of 0, i.e. delta_lcn is not present at
622  *	  all, which is then interpreted by the driver as lcn = -1.
623  *	  NOTE: Even uncompressed files can be sparse on NTFS 3.0 volumes, then
624  *	  the same principles apply as above, except that the length is not
625  *	  restricted to being any particular value.
626  *
627  *   2) The data in the block is not compressed:
628  *	  This happens when compression doesn't reduce the size of the block
629  *	  in clusters. I.e. if compression has a small effect so that the
630  *	  compressed data still occupies X clusters, then the uncompressed data
631  *	  is stored in the block.
632  *	  This case is recognised by the fact that the runlist entry has
633  *	  length = X and lcn >= 0. The mapping pairs array stores this as
634  *	  normal with a run length of X and some specific delta_lcn, i.e.
635  *	  delta_lcn has to be present.
636  *
637  *   3) The data in the block is compressed:
638  *	  The common case. This case is recognised by the fact that the run
639  *	  list entry has length L < X and lcn >= 0. The mapping pairs array
640  *	  stores this as normal with a run length of X and some specific
641  *	  delta_lcn, i.e. delta_lcn has to be present. This runlist entry is
642  *	  immediately followed by a sparse entry with length = X - L and
643  *	  lcn = -1. The latter entry is to make up the vcn counting to the
644  *	  full compression block size X.
645  *
646  * In fact, life is more complicated because adjacent entries of the same type
647  * can be coalesced. This means that one has to keep track of the number of
648  * clusters handled and work on a basis of X clusters at a time being one
649  * block. An example: if length L > X this means that this particular runlist
650  * entry contains a block of length X and part of one or more blocks of length
651  * L - X. Another example: if length L < X, this does not necessarily mean that
652  * the block is compressed as it might be that the lcn changes inside the block
653  * and hence the following runlist entry describes the continuation of the
654  * potentially compressed block. The block would be compressed if the
655  * following runlist entry describes at least X - L sparse clusters, thus
656  * making up the compression block length as described in point 3 above. (Of
657  * course, there can be several runlist entries with small lengths so that the
658  * sparse entry does not follow the first data containing entry with
659  * length < X.)
660  *
661  * NOTE: At the end of the compressed attribute value, there most likely is not
662  * just the right amount of data to make up a compression block, thus this data
663  * is not even attempted to be compressed. It is just stored as is, unless
664  * the number of clusters it occupies is reduced when compressed in which case
665  * it is stored as a compressed compression block, complete with sparse
666  * clusters at the end.
667  */
668 
669 /*
670  * Flags of resident attributes (8-bit).
671  */
672 enum {
673 	RESIDENT_ATTR_IS_INDEXED = 0x01, /* Attribute is referenced in an index
674 					    (has implications for deleting and
675 					    modifying the attribute). */
676 } __attribute__ ((__packed__));
677 
678 typedef u8 RESIDENT_ATTR_FLAGS;
679 
680 /*
681  * Attribute record header. Always aligned to 8-byte boundary.
682  */
683 typedef struct {
684 /*Ofs*/
685 /*  0*/	ATTR_TYPE type;		/* The (32-bit) type of the attribute. */
686 /*  4*/	le32 length;		/* Byte size of the resident part of the
687 				   attribute (aligned to 8-byte boundary).
688 				   Used to get to the next attribute. */
689 /*  8*/	u8 non_resident;	/* If 0, attribute is resident.
690 				   If 1, attribute is non-resident. */
691 /*  9*/	u8 name_length;		/* Unicode character size of name of attribute.
692 				   0 if unnamed. */
693 /* 10*/	le16 name_offset;	/* If name_length != 0, the byte offset to the
694 				   beginning of the name from the attribute
695 				   record. Note that the name is stored as a
696 				   Unicode string. When creating, place offset
697 				   just at the end of the record header. Then,
698 				   follow with attribute value or mapping pairs
699 				   array, resident and non-resident attributes
700 				   respectively, aligning to an 8-byte
701 				   boundary. */
702 /* 12*/	ATTR_FLAGS flags;	/* Flags describing the attribute. */
703 /* 14*/	le16 instance;		/* The instance of this attribute record. This
704 				   number is unique within this mft record (see
705 				   MFT_RECORD/next_attribute_instance notes in
706 				   in mft.h for more details). */
707 /* 16*/	union {
708 		/* Resident attributes. */
709 		struct {
710 /* 16 */		le32 value_length;/* Byte size of attribute value. */
711 /* 20 */		le16 value_offset;/* Byte offset of the attribute
712 					     value from the start of the
713 					     attribute record. When creating,
714 					     align to 8-byte boundary if we
715 					     have a name present as this might
716 					     not have a length of a multiple
717 					     of 8-bytes. */
718 /* 22 */		RESIDENT_ATTR_FLAGS flags; /* See above. */
719 /* 23 */		s8 reserved;	  /* Reserved/alignment to 8-byte
720 					     boundary. */
721 		} __attribute__ ((__packed__)) resident;
722 		/* Non-resident attributes. */
723 		struct {
724 /* 16*/			leVCN lowest_vcn;/* Lowest valid virtual cluster number
725 				for this portion of the attribute value or
726 				0 if this is the only extent (usually the
727 				case). - Only when an attribute list is used
728 				does lowest_vcn != 0 ever occur. */
729 /* 24*/			leVCN highest_vcn;/* Highest valid vcn of this extent of
730 				the attribute value. - Usually there is only one
731 				portion, so this usually equals the attribute
732 				value size in clusters minus 1. Can be -1 for
733 				zero length files. Can be 0 for "single extent"
734 				attributes. */
735 /* 32*/			le16 mapping_pairs_offset; /* Byte offset from the
736 				beginning of the structure to the mapping pairs
737 				array which contains the mappings between the
738 				vcns and the logical cluster numbers (lcns).
739 				When creating, place this at the end of this
740 				record header aligned to 8-byte boundary. */
741 /* 34*/			u8 compression_unit; /* The compression unit expressed
742 				as the log to the base 2 of the number of
743 				clusters in a compression unit.  0 means not
744 				compressed.  (This effectively limits the
745 				compression unit size to be a power of two
746 				clusters.)  WinNT4 only uses a value of 4.
747 				Sparse files have this set to 0 on XPSP2. */
748 /* 35*/			u8 reserved[5];		/* Align to 8-byte boundary. */
749 /* The sizes below are only used when lowest_vcn is zero, as otherwise it would
750    be difficult to keep them up-to-date.*/
751 /* 40*/			sle64 allocated_size;	/* Byte size of disk space
752 				allocated to hold the attribute value. Always
753 				is a multiple of the cluster size. When a file
754 				is compressed, this field is a multiple of the
755 				compression block size (2^compression_unit) and
756 				it represents the logically allocated space
757 				rather than the actual on disk usage. For this
758 				use the compressed_size (see below). */
759 /* 48*/			sle64 data_size;	/* Byte size of the attribute
760 				value. Can be larger than allocated_size if
761 				attribute value is compressed or sparse. */
762 /* 56*/			sle64 initialized_size;	/* Byte size of initialized
763 				portion of the attribute value. Usually equals
764 				data_size. */
765 /* sizeof(uncompressed attr) = 64*/
766 /* 64*/			sle64 compressed_size;	/* Byte size of the attribute
767 				value after compression.  Only present when
768 				compressed or sparse.  Always is a multiple of
769 				the cluster size.  Represents the actual amount
770 				of disk space being used on the disk. */
771 /* sizeof(compressed attr) = 72*/
772 		} __attribute__ ((__packed__)) non_resident;
773 	} __attribute__ ((__packed__)) data;
774 } __attribute__ ((__packed__)) ATTR_RECORD;
775 
776 typedef ATTR_RECORD ATTR_REC;
777 
778 /*
779  * File attribute flags (32-bit) appearing in the file_attributes fields of the
780  * STANDARD_INFORMATION attribute of MFT_RECORDs and the FILENAME_ATTR
781  * attributes of MFT_RECORDs and directory index entries.
782  *
783  * All of the below flags appear in the directory index entries but only some
784  * appear in the STANDARD_INFORMATION attribute whilst only some others appear
785  * in the FILENAME_ATTR attribute of MFT_RECORDs.  Unless otherwise stated the
786  * flags appear in all of the above.
787  */
788 enum {
789 	FILE_ATTR_READONLY		= cpu_to_le32(0x00000001),
790 	FILE_ATTR_HIDDEN		= cpu_to_le32(0x00000002),
791 	FILE_ATTR_SYSTEM		= cpu_to_le32(0x00000004),
792 	/* Old DOS volid. Unused in NT.	= cpu_to_le32(0x00000008), */
793 
794 	FILE_ATTR_DIRECTORY		= cpu_to_le32(0x00000010),
795 	/* Note, FILE_ATTR_DIRECTORY is not considered valid in NT.  It is
796 	   reserved for the DOS SUBDIRECTORY flag. */
797 	FILE_ATTR_ARCHIVE		= cpu_to_le32(0x00000020),
798 	FILE_ATTR_DEVICE		= cpu_to_le32(0x00000040),
799 	FILE_ATTR_NORMAL		= cpu_to_le32(0x00000080),
800 
801 	FILE_ATTR_TEMPORARY		= cpu_to_le32(0x00000100),
802 	FILE_ATTR_SPARSE_FILE		= cpu_to_le32(0x00000200),
803 	FILE_ATTR_REPARSE_POINT		= cpu_to_le32(0x00000400),
804 	FILE_ATTR_COMPRESSED		= cpu_to_le32(0x00000800),
805 
806 	FILE_ATTR_OFFLINE		= cpu_to_le32(0x00001000),
807 	FILE_ATTR_NOT_CONTENT_INDEXED	= cpu_to_le32(0x00002000),
808 	FILE_ATTR_ENCRYPTED		= cpu_to_le32(0x00004000),
809 
810 	FILE_ATTR_VALID_FLAGS		= cpu_to_le32(0x00007fb7),
811 	/* Note, FILE_ATTR_VALID_FLAGS masks out the old DOS VolId and the
812 	   FILE_ATTR_DEVICE and preserves everything else.  This mask is used
813 	   to obtain all flags that are valid for reading. */
814 	FILE_ATTR_VALID_SET_FLAGS	= cpu_to_le32(0x000031a7),
815 	/* Note, FILE_ATTR_VALID_SET_FLAGS masks out the old DOS VolId, the
816 	   F_A_DEVICE, F_A_DIRECTORY, F_A_SPARSE_FILE, F_A_REPARSE_POINT,
817 	   F_A_COMPRESSED, and F_A_ENCRYPTED and preserves the rest.  This mask
818 	   is used to obtain all flags that are valid for setting. */
819 	/*
820 	 * The flag FILE_ATTR_DUP_FILENAME_INDEX_PRESENT is present in all
821 	 * FILENAME_ATTR attributes but not in the STANDARD_INFORMATION
822 	 * attribute of an mft record.
823 	 */
824 	FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT	= cpu_to_le32(0x10000000),
825 	/* Note, this is a copy of the corresponding bit from the mft record,
826 	   telling us whether this is a directory or not, i.e. whether it has
827 	   an index root attribute or not. */
828 	FILE_ATTR_DUP_VIEW_INDEX_PRESENT	= cpu_to_le32(0x20000000),
829 	/* Note, this is a copy of the corresponding bit from the mft record,
830 	   telling us whether this file has a view index present (eg. object id
831 	   index, quota index, one of the security indexes or the encrypting
832 	   filesystem related indexes). */
833 };
834 
835 typedef le32 FILE_ATTR_FLAGS;
836 
837 /*
838  * NOTE on times in NTFS: All times are in MS standard time format, i.e. they
839  * are the number of 100-nanosecond intervals since 1st January 1601, 00:00:00
840  * universal coordinated time (UTC). (In Linux time starts 1st January 1970,
841  * 00:00:00 UTC and is stored as the number of 1-second intervals since then.)
842  */
843 
844 /*
845  * Attribute: Standard information (0x10).
846  *
847  * NOTE: Always resident.
848  * NOTE: Present in all base file records on a volume.
849  * NOTE: There is conflicting information about the meaning of each of the time
850  *	 fields but the meaning as defined below has been verified to be
851  *	 correct by practical experimentation on Windows NT4 SP6a and is hence
852  *	 assumed to be the one and only correct interpretation.
853  */
854 typedef struct {
855 /*Ofs*/
856 /*  0*/	sle64 creation_time;		/* Time file was created. Updated when
857 					   a filename is changed(?). */
858 /*  8*/	sle64 last_data_change_time;	/* Time the data attribute was last
859 					   modified. */
860 /* 16*/	sle64 last_mft_change_time;	/* Time this mft record was last
861 					   modified. */
862 /* 24*/	sle64 last_access_time;		/* Approximate time when the file was
863 					   last accessed (obviously this is not
864 					   updated on read-only volumes). In
865 					   Windows this is only updated when
866 					   accessed if some time delta has
867 					   passed since the last update. Also,
868 					   last access time updates can be
869 					   disabled altogether for speed. */
870 /* 32*/	FILE_ATTR_FLAGS file_attributes; /* Flags describing the file. */
871 /* 36*/	union {
872 	/* NTFS 1.2 */
873 		struct {
874 		/* 36*/	u8 reserved12[12];	/* Reserved/alignment to 8-byte
875 						   boundary. */
876 		} __attribute__ ((__packed__)) v1;
877 	/* sizeof() = 48 bytes */
878 	/* NTFS 3.x */
879 		struct {
880 /*
881  * If a volume has been upgraded from a previous NTFS version, then these
882  * fields are present only if the file has been accessed since the upgrade.
883  * Recognize the difference by comparing the length of the resident attribute
884  * value. If it is 48, then the following fields are missing. If it is 72 then
885  * the fields are present. Maybe just check like this:
886  *	if (resident.ValueLength < sizeof(STANDARD_INFORMATION)) {
887  *		Assume NTFS 1.2- format.
888  *		If (volume version is 3.x)
889  *			Upgrade attribute to NTFS 3.x format.
890  *		else
891  *			Use NTFS 1.2- format for access.
892  *	} else
893  *		Use NTFS 3.x format for access.
894  * Only problem is that it might be legal to set the length of the value to
895  * arbitrarily large values thus spoiling this check. - But chkdsk probably
896  * views that as a corruption, assuming that it behaves like this for all
897  * attributes.
898  */
899 		/* 36*/	le32 maximum_versions;	/* Maximum allowed versions for
900 				file. Zero if version numbering is disabled. */
901 		/* 40*/	le32 version_number;	/* This file's version (if any).
902 				Set to zero if maximum_versions is zero. */
903 		/* 44*/	le32 class_id;		/* Class id from bidirectional
904 				class id index (?). */
905 		/* 48*/	le32 owner_id;		/* Owner_id of the user owning
906 				the file. Translate via $Q index in FILE_Extend
907 				/$Quota to the quota control entry for the user
908 				owning the file. Zero if quotas are disabled. */
909 		/* 52*/	le32 security_id;	/* Security_id for the file.
910 				Translate via $SII index and $SDS data stream
911 				in FILE_Secure to the security descriptor. */
912 		/* 56*/	le64 quota_charged;	/* Byte size of the charge to
913 				the quota for all streams of the file. Note: Is
914 				zero if quotas are disabled. */
915 		/* 64*/	leUSN usn;		/* Last update sequence number
916 				of the file.  This is a direct index into the
917 				transaction log file ($UsnJrnl).  It is zero if
918 				the usn journal is disabled or this file has
919 				not been subject to logging yet.  See usnjrnl.h
920 				for details. */
921 		} __attribute__ ((__packed__)) v3;
922 	/* sizeof() = 72 bytes (NTFS 3.x) */
923 	} __attribute__ ((__packed__)) ver;
924 } __attribute__ ((__packed__)) STANDARD_INFORMATION;
925 
926 /*
927  * Attribute: Attribute list (0x20).
928  *
929  * - Can be either resident or non-resident.
930  * - Value consists of a sequence of variable length, 8-byte aligned,
931  * ATTR_LIST_ENTRY records.
932  * - The list is not terminated by anything at all! The only way to know when
933  * the end is reached is to keep track of the current offset and compare it to
934  * the attribute value size.
935  * - The attribute list attribute contains one entry for each attribute of
936  * the file in which the list is located, except for the list attribute
937  * itself. The list is sorted: first by attribute type, second by attribute
938  * name (if present), third by instance number. The extents of one
939  * non-resident attribute (if present) immediately follow after the initial
940  * extent. They are ordered by lowest_vcn and have their instace set to zero.
941  * It is not allowed to have two attributes with all sorting keys equal.
942  * - Further restrictions:
943  *	- If not resident, the vcn to lcn mapping array has to fit inside the
944  *	  base mft record.
945  *	- The attribute list attribute value has a maximum size of 256kb. This
946  *	  is imposed by the Windows cache manager.
947  * - Attribute lists are only used when the attributes of mft record do not
948  * fit inside the mft record despite all attributes (that can be made
949  * non-resident) having been made non-resident. This can happen e.g. when:
950  *	- File has a large number of hard links (lots of file name
951  *	  attributes present).
952  *	- The mapping pairs array of some non-resident attribute becomes so
953  *	  large due to fragmentation that it overflows the mft record.
954  *	- The security descriptor is very complex (not applicable to
955  *	  NTFS 3.0 volumes).
956  *	- There are many named streams.
957  */
958 typedef struct {
959 /*Ofs*/
960 /*  0*/	ATTR_TYPE type;		/* Type of referenced attribute. */
961 /*  4*/	le16 length;		/* Byte size of this entry (8-byte aligned). */
962 /*  6*/	u8 name_length;		/* Size in Unicode chars of the name of the
963 				   attribute or 0 if unnamed. */
964 /*  7*/	u8 name_offset;		/* Byte offset to beginning of attribute name
965 				   (always set this to where the name would
966 				   start even if unnamed). */
967 /*  8*/	leVCN lowest_vcn;	/* Lowest virtual cluster number of this portion
968 				   of the attribute value. This is usually 0. It
969 				   is non-zero for the case where one attribute
970 				   does not fit into one mft record and thus
971 				   several mft records are allocated to hold
972 				   this attribute. In the latter case, each mft
973 				   record holds one extent of the attribute and
974 				   there is one attribute list entry for each
975 				   extent. NOTE: This is DEFINITELY a signed
976 				   value! The windows driver uses cmp, followed
977 				   by jg when comparing this, thus it treats it
978 				   as signed. */
979 /* 16*/	leMFT_REF mft_reference;/* The reference of the mft record holding
980 				   the ATTR_RECORD for this portion of the
981 				   attribute value. */
982 /* 24*/	le16 instance;		/* If lowest_vcn = 0, the instance of the
983 				   attribute being referenced; otherwise 0. */
984 /* 26*/	ntfschar name[0];	/* Use when creating only. When reading use
985 				   name_offset to determine the location of the
986 				   name. */
987 /* sizeof() = 26 + (attribute_name_length * 2) bytes */
988 } __attribute__ ((__packed__)) ATTR_LIST_ENTRY;
989 
990 /*
991  * The maximum allowed length for a file name.
992  */
993 #define MAXIMUM_FILE_NAME_LENGTH	255
994 
995 /*
996  * Possible namespaces for filenames in ntfs (8-bit).
997  */
998 enum {
999 	FILE_NAME_POSIX		= 0x00,
1000 	/* This is the largest namespace. It is case sensitive and allows all
1001 	   Unicode characters except for: '\0' and '/'.  Beware that in
1002 	   WinNT/2k/2003 by default files which eg have the same name except
1003 	   for their case will not be distinguished by the standard utilities
1004 	   and thus a "del filename" will delete both "filename" and "fileName"
1005 	   without warning.  However if for example Services For Unix (SFU) are
1006 	   installed and the case sensitive option was enabled at installation
1007 	   time, then you can create/access/delete such files.
1008 	   Note that even SFU places restrictions on the filenames beyond the
1009 	   '\0' and '/' and in particular the following set of characters is
1010 	   not allowed: '"', '/', '<', '>', '\'.  All other characters,
1011 	   including the ones no allowed in WIN32 namespace are allowed.
1012 	   Tested with SFU 3.5 (this is now free) running on Windows XP. */
1013 	FILE_NAME_WIN32		= 0x01,
1014 	/* The standard WinNT/2k NTFS long filenames. Case insensitive.  All
1015 	   Unicode chars except: '\0', '"', '*', '/', ':', '<', '>', '?', '\',
1016 	   and '|'.  Further, names cannot end with a '.' or a space. */
1017 	FILE_NAME_DOS		= 0x02,
1018 	/* The standard DOS filenames (8.3 format). Uppercase only.  All 8-bit
1019 	   characters greater space, except: '"', '*', '+', ',', '/', ':', ';',
1020 	   '<', '=', '>', '?', and '\'. */
1021 	FILE_NAME_WIN32_AND_DOS	= 0x03,
1022 	/* 3 means that both the Win32 and the DOS filenames are identical and
1023 	   hence have been saved in this single filename record. */
1024 } __attribute__ ((__packed__));
1025 
1026 typedef u8 FILE_NAME_TYPE_FLAGS;
1027 
1028 /*
1029  * Attribute: Filename (0x30).
1030  *
1031  * NOTE: Always resident.
1032  * NOTE: All fields, except the parent_directory, are only updated when the
1033  *	 filename is changed. Until then, they just become out of sync with
1034  *	 reality and the more up to date values are present in the standard
1035  *	 information attribute.
1036  * NOTE: There is conflicting information about the meaning of each of the time
1037  *	 fields but the meaning as defined below has been verified to be
1038  *	 correct by practical experimentation on Windows NT4 SP6a and is hence
1039  *	 assumed to be the one and only correct interpretation.
1040  */
1041 typedef struct {
1042 /*hex ofs*/
1043 /*  0*/	leMFT_REF parent_directory;	/* Directory this filename is
1044 					   referenced from. */
1045 /*  8*/	sle64 creation_time;		/* Time file was created. */
1046 /* 10*/	sle64 last_data_change_time;	/* Time the data attribute was last
1047 					   modified. */
1048 /* 18*/	sle64 last_mft_change_time;	/* Time this mft record was last
1049 					   modified. */
1050 /* 20*/	sle64 last_access_time;		/* Time this mft record was last
1051 					   accessed. */
1052 /* 28*/	sle64 allocated_size;		/* Byte size of on-disk allocated space
1053 					   for the unnamed data attribute.  So
1054 					   for normal $DATA, this is the
1055 					   allocated_size from the unnamed
1056 					   $DATA attribute and for compressed
1057 					   and/or sparse $DATA, this is the
1058 					   compressed_size from the unnamed
1059 					   $DATA attribute.  For a directory or
1060 					   other inode without an unnamed $DATA
1061 					   attribute, this is always 0.  NOTE:
1062 					   This is a multiple of the cluster
1063 					   size. */
1064 /* 30*/	sle64 data_size;		/* Byte size of actual data in unnamed
1065 					   data attribute.  For a directory or
1066 					   other inode without an unnamed $DATA
1067 					   attribute, this is always 0. */
1068 /* 38*/	FILE_ATTR_FLAGS file_attributes;	/* Flags describing the file. */
1069 /* 3c*/	union {
1070 	/* 3c*/	struct {
1071 		/* 3c*/	le16 packed_ea_size;	/* Size of the buffer needed to
1072 						   pack the extended attributes
1073 						   (EAs), if such are present.*/
1074 		/* 3e*/	le16 reserved;		/* Reserved for alignment. */
1075 		} __attribute__ ((__packed__)) ea;
1076 	/* 3c*/	struct {
1077 		/* 3c*/	le32 reparse_point_tag;	/* Type of reparse point,
1078 						   present only in reparse
1079 						   points and only if there are
1080 						   no EAs. */
1081 		} __attribute__ ((__packed__)) rp;
1082 	} __attribute__ ((__packed__)) type;
1083 /* 40*/	u8 file_name_length;			/* Length of file name in
1084 						   (Unicode) characters. */
1085 /* 41*/	FILE_NAME_TYPE_FLAGS file_name_type;	/* Namespace of the file name.*/
1086 /* 42*/	ntfschar file_name[0];			/* File name in Unicode. */
1087 } __attribute__ ((__packed__)) FILE_NAME_ATTR;
1088 
1089 /*
1090  * GUID structures store globally unique identifiers (GUID). A GUID is a
1091  * 128-bit value consisting of one group of eight hexadecimal digits, followed
1092  * by three groups of four hexadecimal digits each, followed by one group of
1093  * twelve hexadecimal digits. GUIDs are Microsoft's implementation of the
1094  * distributed computing environment (DCE) universally unique identifier (UUID).
1095  * Example of a GUID:
1096  *	1F010768-5A73-BC91-0010A52216A7
1097  */
1098 typedef struct {
1099 	le32 data1;	/* The first eight hexadecimal digits of the GUID. */
1100 	le16 data2;	/* The first group of four hexadecimal digits. */
1101 	le16 data3;	/* The second group of four hexadecimal digits. */
1102 	u8 data4[8];	/* The first two bytes are the third group of four
1103 			   hexadecimal digits. The remaining six bytes are the
1104 			   final 12 hexadecimal digits. */
1105 } __attribute__ ((__packed__)) GUID;
1106 
1107 /*
1108  * FILE_Extend/$ObjId contains an index named $O. This index contains all
1109  * object_ids present on the volume as the index keys and the corresponding
1110  * mft_record numbers as the index entry data parts. The data part (defined
1111  * below) also contains three other object_ids:
1112  *	birth_volume_id - object_id of FILE_Volume on which the file was first
1113  *			  created. Optional (i.e. can be zero).
1114  *	birth_object_id - object_id of file when it was first created. Usually
1115  *			  equals the object_id. Optional (i.e. can be zero).
1116  *	domain_id	- Reserved (always zero).
1117  */
1118 typedef struct {
1119 	leMFT_REF mft_reference;/* Mft record containing the object_id in
1120 				   the index entry key. */
1121 	union {
1122 		struct {
1123 			GUID birth_volume_id;
1124 			GUID birth_object_id;
1125 			GUID domain_id;
1126 		} __attribute__ ((__packed__)) origin;
1127 		u8 extended_info[48];
1128 	} __attribute__ ((__packed__)) opt;
1129 } __attribute__ ((__packed__)) OBJ_ID_INDEX_DATA;
1130 
1131 /*
1132  * Attribute: Object id (NTFS 3.0+) (0x40).
1133  *
1134  * NOTE: Always resident.
1135  */
1136 typedef struct {
1137 	GUID object_id;				/* Unique id assigned to the
1138 						   file.*/
1139 	/* The following fields are optional. The attribute value size is 16
1140 	   bytes, i.e. sizeof(GUID), if these are not present at all. Note,
1141 	   the entries can be present but one or more (or all) can be zero
1142 	   meaning that that particular value(s) is(are) not defined. */
1143 	union {
1144 		struct {
1145 			GUID birth_volume_id;	/* Unique id of volume on which
1146 						   the file was first created.*/
1147 			GUID birth_object_id;	/* Unique id of file when it was
1148 						   first created. */
1149 			GUID domain_id;		/* Reserved, zero. */
1150 		} __attribute__ ((__packed__)) origin;
1151 		u8 extended_info[48];
1152 	} __attribute__ ((__packed__)) opt;
1153 } __attribute__ ((__packed__)) OBJECT_ID_ATTR;
1154 
1155 /*
1156  * The pre-defined IDENTIFIER_AUTHORITIES used as SID_IDENTIFIER_AUTHORITY in
1157  * the SID structure (see below).
1158  */
1159 //typedef enum {					/* SID string prefix. */
1160 //	SECURITY_NULL_SID_AUTHORITY	= {0, 0, 0, 0, 0, 0},	/* S-1-0 */
1161 //	SECURITY_WORLD_SID_AUTHORITY	= {0, 0, 0, 0, 0, 1},	/* S-1-1 */
1162 //	SECURITY_LOCAL_SID_AUTHORITY	= {0, 0, 0, 0, 0, 2},	/* S-1-2 */
1163 //	SECURITY_CREATOR_SID_AUTHORITY	= {0, 0, 0, 0, 0, 3},	/* S-1-3 */
1164 //	SECURITY_NON_UNIQUE_AUTHORITY	= {0, 0, 0, 0, 0, 4},	/* S-1-4 */
1165 //	SECURITY_NT_SID_AUTHORITY	= {0, 0, 0, 0, 0, 5},	/* S-1-5 */
1166 //} IDENTIFIER_AUTHORITIES;
1167 
1168 /*
1169  * These relative identifiers (RIDs) are used with the above identifier
1170  * authorities to make up universal well-known SIDs.
1171  *
1172  * Note: The relative identifier (RID) refers to the portion of a SID, which
1173  * identifies a user or group in relation to the authority that issued the SID.
1174  * For example, the universal well-known SID Creator Owner ID (S-1-3-0) is
1175  * made up of the identifier authority SECURITY_CREATOR_SID_AUTHORITY (3) and
1176  * the relative identifier SECURITY_CREATOR_OWNER_RID (0).
1177  */
1178 typedef enum {					/* Identifier authority. */
1179 	SECURITY_NULL_RID		  = 0,	/* S-1-0 */
1180 	SECURITY_WORLD_RID		  = 0,	/* S-1-1 */
1181 	SECURITY_LOCAL_RID		  = 0,	/* S-1-2 */
1182 
1183 	SECURITY_CREATOR_OWNER_RID	  = 0,	/* S-1-3 */
1184 	SECURITY_CREATOR_GROUP_RID	  = 1,	/* S-1-3 */
1185 
1186 	SECURITY_CREATOR_OWNER_SERVER_RID = 2,	/* S-1-3 */
1187 	SECURITY_CREATOR_GROUP_SERVER_RID = 3,	/* S-1-3 */
1188 
1189 	SECURITY_DIALUP_RID		  = 1,
1190 	SECURITY_NETWORK_RID		  = 2,
1191 	SECURITY_BATCH_RID		  = 3,
1192 	SECURITY_INTERACTIVE_RID	  = 4,
1193 	SECURITY_SERVICE_RID		  = 6,
1194 	SECURITY_ANONYMOUS_LOGON_RID	  = 7,
1195 	SECURITY_PROXY_RID		  = 8,
1196 	SECURITY_ENTERPRISE_CONTROLLERS_RID=9,
1197 	SECURITY_SERVER_LOGON_RID	  = 9,
1198 	SECURITY_PRINCIPAL_SELF_RID	  = 0xa,
1199 	SECURITY_AUTHENTICATED_USER_RID	  = 0xb,
1200 	SECURITY_RESTRICTED_CODE_RID	  = 0xc,
1201 	SECURITY_TERMINAL_SERVER_RID	  = 0xd,
1202 
1203 	SECURITY_LOGON_IDS_RID		  = 5,
1204 	SECURITY_LOGON_IDS_RID_COUNT	  = 3,
1205 
1206 	SECURITY_LOCAL_SYSTEM_RID	  = 0x12,
1207 
1208 	SECURITY_NT_NON_UNIQUE		  = 0x15,
1209 
1210 	SECURITY_BUILTIN_DOMAIN_RID	  = 0x20,
1211 
1212 	/*
1213 	 * Well-known domain relative sub-authority values (RIDs).
1214 	 */
1215 
1216 	/* Users. */
1217 	DOMAIN_USER_RID_ADMIN		  = 0x1f4,
1218 	DOMAIN_USER_RID_GUEST		  = 0x1f5,
1219 	DOMAIN_USER_RID_KRBTGT		  = 0x1f6,
1220 
1221 	/* Groups. */
1222 	DOMAIN_GROUP_RID_ADMINS		  = 0x200,
1223 	DOMAIN_GROUP_RID_USERS		  = 0x201,
1224 	DOMAIN_GROUP_RID_GUESTS		  = 0x202,
1225 	DOMAIN_GROUP_RID_COMPUTERS	  = 0x203,
1226 	DOMAIN_GROUP_RID_CONTROLLERS	  = 0x204,
1227 	DOMAIN_GROUP_RID_CERT_ADMINS	  = 0x205,
1228 	DOMAIN_GROUP_RID_SCHEMA_ADMINS	  = 0x206,
1229 	DOMAIN_GROUP_RID_ENTERPRISE_ADMINS= 0x207,
1230 	DOMAIN_GROUP_RID_POLICY_ADMINS	  = 0x208,
1231 
1232 	/* Aliases. */
1233 	DOMAIN_ALIAS_RID_ADMINS		  = 0x220,
1234 	DOMAIN_ALIAS_RID_USERS		  = 0x221,
1235 	DOMAIN_ALIAS_RID_GUESTS		  = 0x222,
1236 	DOMAIN_ALIAS_RID_POWER_USERS	  = 0x223,
1237 
1238 	DOMAIN_ALIAS_RID_ACCOUNT_OPS	  = 0x224,
1239 	DOMAIN_ALIAS_RID_SYSTEM_OPS	  = 0x225,
1240 	DOMAIN_ALIAS_RID_PRINT_OPS	  = 0x226,
1241 	DOMAIN_ALIAS_RID_BACKUP_OPS	  = 0x227,
1242 
1243 	DOMAIN_ALIAS_RID_REPLICATOR	  = 0x228,
1244 	DOMAIN_ALIAS_RID_RAS_SERVERS	  = 0x229,
1245 	DOMAIN_ALIAS_RID_PREW2KCOMPACCESS = 0x22a,
1246 } RELATIVE_IDENTIFIERS;
1247 
1248 /*
1249  * The universal well-known SIDs:
1250  *
1251  *	NULL_SID			S-1-0-0
1252  *	WORLD_SID			S-1-1-0
1253  *	LOCAL_SID			S-1-2-0
1254  *	CREATOR_OWNER_SID		S-1-3-0
1255  *	CREATOR_GROUP_SID		S-1-3-1
1256  *	CREATOR_OWNER_SERVER_SID	S-1-3-2
1257  *	CREATOR_GROUP_SERVER_SID	S-1-3-3
1258  *
1259  *	(Non-unique IDs)		S-1-4
1260  *
1261  * NT well-known SIDs:
1262  *
1263  *	NT_AUTHORITY_SID	S-1-5
1264  *	DIALUP_SID		S-1-5-1
1265  *
1266  *	NETWORD_SID		S-1-5-2
1267  *	BATCH_SID		S-1-5-3
1268  *	INTERACTIVE_SID		S-1-5-4
1269  *	SERVICE_SID		S-1-5-6
1270  *	ANONYMOUS_LOGON_SID	S-1-5-7		(aka null logon session)
1271  *	PROXY_SID		S-1-5-8
1272  *	SERVER_LOGON_SID	S-1-5-9		(aka domain controller account)
1273  *	SELF_SID		S-1-5-10	(self RID)
1274  *	AUTHENTICATED_USER_SID	S-1-5-11
1275  *	RESTRICTED_CODE_SID	S-1-5-12	(running restricted code)
1276  *	TERMINAL_SERVER_SID	S-1-5-13	(running on terminal server)
1277  *
1278  *	(Logon IDs)		S-1-5-5-X-Y
1279  *
1280  *	(NT non-unique IDs)	S-1-5-0x15-...
1281  *
1282  *	(Built-in domain)	S-1-5-0x20
1283  */
1284 
1285 /*
1286  * The SID_IDENTIFIER_AUTHORITY is a 48-bit value used in the SID structure.
1287  *
1288  * NOTE: This is stored as a big endian number, hence the high_part comes
1289  * before the low_part.
1290  */
1291 typedef union {
1292 	struct {
1293 		u16 high_part;	/* High 16-bits. */
1294 		u32 low_part;	/* Low 32-bits. */
1295 	} __attribute__ ((__packed__)) parts;
1296 	u8 value[6];		/* Value as individual bytes. */
1297 } __attribute__ ((__packed__)) SID_IDENTIFIER_AUTHORITY;
1298 
1299 /*
1300  * The SID structure is a variable-length structure used to uniquely identify
1301  * users or groups. SID stands for security identifier.
1302  *
1303  * The standard textual representation of the SID is of the form:
1304  *	S-R-I-S-S...
1305  * Where:
1306  *    - The first "S" is the literal character 'S' identifying the following
1307  *	digits as a SID.
1308  *    - R is the revision level of the SID expressed as a sequence of digits
1309  *	either in decimal or hexadecimal (if the later, prefixed by "0x").
1310  *    - I is the 48-bit identifier_authority, expressed as digits as R above.
1311  *    - S... is one or more sub_authority values, expressed as digits as above.
1312  *
1313  * Example SID; the domain-relative SID of the local Administrators group on
1314  * Windows NT/2k:
1315  *	S-1-5-32-544
1316  * This translates to a SID with:
1317  *	revision = 1,
1318  *	sub_authority_count = 2,
1319  *	identifier_authority = {0,0,0,0,0,5},	// SECURITY_NT_AUTHORITY
1320  *	sub_authority[0] = 32,			// SECURITY_BUILTIN_DOMAIN_RID
1321  *	sub_authority[1] = 544			// DOMAIN_ALIAS_RID_ADMINS
1322  */
1323 typedef struct {
1324 	u8 revision;
1325 	u8 sub_authority_count;
1326 	SID_IDENTIFIER_AUTHORITY identifier_authority;
1327 	le32 sub_authority[1];		/* At least one sub_authority. */
1328 } __attribute__ ((__packed__)) SID;
1329 
1330 /*
1331  * Current constants for SIDs.
1332  */
1333 typedef enum {
1334 	SID_REVISION			=  1,	/* Current revision level. */
1335 	SID_MAX_SUB_AUTHORITIES		= 15,	/* Maximum number of those. */
1336 	SID_RECOMMENDED_SUB_AUTHORITIES	=  1,	/* Will change to around 6 in
1337 						   a future revision. */
1338 } SID_CONSTANTS;
1339 
1340 /*
1341  * The predefined ACE types (8-bit, see below).
1342  */
1343 enum {
1344 	ACCESS_MIN_MS_ACE_TYPE		= 0,
1345 	ACCESS_ALLOWED_ACE_TYPE		= 0,
1346 	ACCESS_DENIED_ACE_TYPE		= 1,
1347 	SYSTEM_AUDIT_ACE_TYPE		= 2,
1348 	SYSTEM_ALARM_ACE_TYPE		= 3, /* Not implemented as of Win2k. */
1349 	ACCESS_MAX_MS_V2_ACE_TYPE	= 3,
1350 
1351 	ACCESS_ALLOWED_COMPOUND_ACE_TYPE= 4,
1352 	ACCESS_MAX_MS_V3_ACE_TYPE	= 4,
1353 
1354 	/* The following are Win2k only. */
1355 	ACCESS_MIN_MS_OBJECT_ACE_TYPE	= 5,
1356 	ACCESS_ALLOWED_OBJECT_ACE_TYPE	= 5,
1357 	ACCESS_DENIED_OBJECT_ACE_TYPE	= 6,
1358 	SYSTEM_AUDIT_OBJECT_ACE_TYPE	= 7,
1359 	SYSTEM_ALARM_OBJECT_ACE_TYPE	= 8,
1360 	ACCESS_MAX_MS_OBJECT_ACE_TYPE	= 8,
1361 
1362 	ACCESS_MAX_MS_V4_ACE_TYPE	= 8,
1363 
1364 	/* This one is for WinNT/2k. */
1365 	ACCESS_MAX_MS_ACE_TYPE		= 8,
1366 } __attribute__ ((__packed__));
1367 
1368 typedef u8 ACE_TYPES;
1369 
1370 /*
1371  * The ACE flags (8-bit) for audit and inheritance (see below).
1372  *
1373  * SUCCESSFUL_ACCESS_ACE_FLAG is only used with system audit and alarm ACE
1374  * types to indicate that a message is generated (in Windows!) for successful
1375  * accesses.
1376  *
1377  * FAILED_ACCESS_ACE_FLAG is only used with system audit and alarm ACE types
1378  * to indicate that a message is generated (in Windows!) for failed accesses.
1379  */
1380 enum {
1381 	/* The inheritance flags. */
1382 	OBJECT_INHERIT_ACE		= 0x01,
1383 	CONTAINER_INHERIT_ACE		= 0x02,
1384 	NO_PROPAGATE_INHERIT_ACE	= 0x04,
1385 	INHERIT_ONLY_ACE		= 0x08,
1386 	INHERITED_ACE			= 0x10,	/* Win2k only. */
1387 	VALID_INHERIT_FLAGS		= 0x1f,
1388 
1389 	/* The audit flags. */
1390 	SUCCESSFUL_ACCESS_ACE_FLAG	= 0x40,
1391 	FAILED_ACCESS_ACE_FLAG		= 0x80,
1392 } __attribute__ ((__packed__));
1393 
1394 typedef u8 ACE_FLAGS;
1395 
1396 /*
1397  * An ACE is an access-control entry in an access-control list (ACL).
1398  * An ACE defines access to an object for a specific user or group or defines
1399  * the types of access that generate system-administration messages or alarms
1400  * for a specific user or group. The user or group is identified by a security
1401  * identifier (SID).
1402  *
1403  * Each ACE starts with an ACE_HEADER structure (aligned on 4-byte boundary),
1404  * which specifies the type and size of the ACE. The format of the subsequent
1405  * data depends on the ACE type.
1406  */
1407 typedef struct {
1408 /*Ofs*/
1409 /*  0*/	ACE_TYPES type;		/* Type of the ACE. */
1410 /*  1*/	ACE_FLAGS flags;	/* Flags describing the ACE. */
1411 /*  2*/	le16 size;		/* Size in bytes of the ACE. */
1412 } __attribute__ ((__packed__)) ACE_HEADER;
1413 
1414 /*
1415  * The access mask (32-bit). Defines the access rights.
1416  *
1417  * The specific rights (bits 0 to 15).  These depend on the type of the object
1418  * being secured by the ACE.
1419  */
1420 enum {
1421 	/* Specific rights for files and directories are as follows: */
1422 
1423 	/* Right to read data from the file. (FILE) */
1424 	FILE_READ_DATA			= cpu_to_le32(0x00000001),
1425 	/* Right to list contents of a directory. (DIRECTORY) */
1426 	FILE_LIST_DIRECTORY		= cpu_to_le32(0x00000001),
1427 
1428 	/* Right to write data to the file. (FILE) */
1429 	FILE_WRITE_DATA			= cpu_to_le32(0x00000002),
1430 	/* Right to create a file in the directory. (DIRECTORY) */
1431 	FILE_ADD_FILE			= cpu_to_le32(0x00000002),
1432 
1433 	/* Right to append data to the file. (FILE) */
1434 	FILE_APPEND_DATA		= cpu_to_le32(0x00000004),
1435 	/* Right to create a subdirectory. (DIRECTORY) */
1436 	FILE_ADD_SUBDIRECTORY		= cpu_to_le32(0x00000004),
1437 
1438 	/* Right to read extended attributes. (FILE/DIRECTORY) */
1439 	FILE_READ_EA			= cpu_to_le32(0x00000008),
1440 
1441 	/* Right to write extended attributes. (FILE/DIRECTORY) */
1442 	FILE_WRITE_EA			= cpu_to_le32(0x00000010),
1443 
1444 	/* Right to execute a file. (FILE) */
1445 	FILE_EXECUTE			= cpu_to_le32(0x00000020),
1446 	/* Right to traverse the directory. (DIRECTORY) */
1447 	FILE_TRAVERSE			= cpu_to_le32(0x00000020),
1448 
1449 	/*
1450 	 * Right to delete a directory and all the files it contains (its
1451 	 * children), even if the files are read-only. (DIRECTORY)
1452 	 */
1453 	FILE_DELETE_CHILD		= cpu_to_le32(0x00000040),
1454 
1455 	/* Right to read file attributes. (FILE/DIRECTORY) */
1456 	FILE_READ_ATTRIBUTES		= cpu_to_le32(0x00000080),
1457 
1458 	/* Right to change file attributes. (FILE/DIRECTORY) */
1459 	FILE_WRITE_ATTRIBUTES		= cpu_to_le32(0x00000100),
1460 
1461 	/*
1462 	 * The standard rights (bits 16 to 23).  These are independent of the
1463 	 * type of object being secured.
1464 	 */
1465 
1466 	/* Right to delete the object. */
1467 	DELETE				= cpu_to_le32(0x00010000),
1468 
1469 	/*
1470 	 * Right to read the information in the object's security descriptor,
1471 	 * not including the information in the SACL, i.e. right to read the
1472 	 * security descriptor and owner.
1473 	 */
1474 	READ_CONTROL			= cpu_to_le32(0x00020000),
1475 
1476 	/* Right to modify the DACL in the object's security descriptor. */
1477 	WRITE_DAC			= cpu_to_le32(0x00040000),
1478 
1479 	/* Right to change the owner in the object's security descriptor. */
1480 	WRITE_OWNER			= cpu_to_le32(0x00080000),
1481 
1482 	/*
1483 	 * Right to use the object for synchronization.  Enables a process to
1484 	 * wait until the object is in the signalled state.  Some object types
1485 	 * do not support this access right.
1486 	 */
1487 	SYNCHRONIZE			= cpu_to_le32(0x00100000),
1488 
1489 	/*
1490 	 * The following STANDARD_RIGHTS_* are combinations of the above for
1491 	 * convenience and are defined by the Win32 API.
1492 	 */
1493 
1494 	/* These are currently defined to READ_CONTROL. */
1495 	STANDARD_RIGHTS_READ		= cpu_to_le32(0x00020000),
1496 	STANDARD_RIGHTS_WRITE		= cpu_to_le32(0x00020000),
1497 	STANDARD_RIGHTS_EXECUTE		= cpu_to_le32(0x00020000),
1498 
1499 	/* Combines DELETE, READ_CONTROL, WRITE_DAC, and WRITE_OWNER access. */
1500 	STANDARD_RIGHTS_REQUIRED	= cpu_to_le32(0x000f0000),
1501 
1502 	/*
1503 	 * Combines DELETE, READ_CONTROL, WRITE_DAC, WRITE_OWNER, and
1504 	 * SYNCHRONIZE access.
1505 	 */
1506 	STANDARD_RIGHTS_ALL		= cpu_to_le32(0x001f0000),
1507 
1508 	/*
1509 	 * The access system ACL and maximum allowed access types (bits 24 to
1510 	 * 25, bits 26 to 27 are reserved).
1511 	 */
1512 	ACCESS_SYSTEM_SECURITY		= cpu_to_le32(0x01000000),
1513 	MAXIMUM_ALLOWED			= cpu_to_le32(0x02000000),
1514 
1515 	/*
1516 	 * The generic rights (bits 28 to 31).  These map onto the standard and
1517 	 * specific rights.
1518 	 */
1519 
1520 	/* Read, write, and execute access. */
1521 	GENERIC_ALL			= cpu_to_le32(0x10000000),
1522 
1523 	/* Execute access. */
1524 	GENERIC_EXECUTE			= cpu_to_le32(0x20000000),
1525 
1526 	/*
1527 	 * Write access.  For files, this maps onto:
1528 	 *	FILE_APPEND_DATA | FILE_WRITE_ATTRIBUTES | FILE_WRITE_DATA |
1529 	 *	FILE_WRITE_EA | STANDARD_RIGHTS_WRITE | SYNCHRONIZE
1530 	 * For directories, the mapping has the same numerical value.  See
1531 	 * above for the descriptions of the rights granted.
1532 	 */
1533 	GENERIC_WRITE			= cpu_to_le32(0x40000000),
1534 
1535 	/*
1536 	 * Read access.  For files, this maps onto:
1537 	 *	FILE_READ_ATTRIBUTES | FILE_READ_DATA | FILE_READ_EA |
1538 	 *	STANDARD_RIGHTS_READ | SYNCHRONIZE
1539 	 * For directories, the mapping has the same numberical value.  See
1540 	 * above for the descriptions of the rights granted.
1541 	 */
1542 	GENERIC_READ			= cpu_to_le32(0x80000000),
1543 };
1544 
1545 typedef le32 ACCESS_MASK;
1546 
1547 /*
1548  * The generic mapping array. Used to denote the mapping of each generic
1549  * access right to a specific access mask.
1550  *
1551  * FIXME: What exactly is this and what is it for? (AIA)
1552  */
1553 typedef struct {
1554 	ACCESS_MASK generic_read;
1555 	ACCESS_MASK generic_write;
1556 	ACCESS_MASK generic_execute;
1557 	ACCESS_MASK generic_all;
1558 } __attribute__ ((__packed__)) GENERIC_MAPPING;
1559 
1560 /*
1561  * The predefined ACE type structures are as defined below.
1562  */
1563 
1564 /*
1565  * ACCESS_ALLOWED_ACE, ACCESS_DENIED_ACE, SYSTEM_AUDIT_ACE, SYSTEM_ALARM_ACE
1566  */
1567 typedef struct {
1568 /*  0	ACE_HEADER; -- Unfolded here as gcc doesn't like unnamed structs. */
1569 	ACE_TYPES type;		/* Type of the ACE. */
1570 	ACE_FLAGS flags;	/* Flags describing the ACE. */
1571 	le16 size;		/* Size in bytes of the ACE. */
1572 /*  4*/	ACCESS_MASK mask;	/* Access mask associated with the ACE. */
1573 
1574 /*  8*/	SID sid;		/* The SID associated with the ACE. */
1575 } __attribute__ ((__packed__)) ACCESS_ALLOWED_ACE, ACCESS_DENIED_ACE,
1576 			       SYSTEM_AUDIT_ACE, SYSTEM_ALARM_ACE;
1577 
1578 /*
1579  * The object ACE flags (32-bit).
1580  */
1581 enum {
1582 	ACE_OBJECT_TYPE_PRESENT			= cpu_to_le32(1),
1583 	ACE_INHERITED_OBJECT_TYPE_PRESENT	= cpu_to_le32(2),
1584 };
1585 
1586 typedef le32 OBJECT_ACE_FLAGS;
1587 
1588 typedef struct {
1589 /*  0	ACE_HEADER; -- Unfolded here as gcc doesn't like unnamed structs. */
1590 	ACE_TYPES type;		/* Type of the ACE. */
1591 	ACE_FLAGS flags;	/* Flags describing the ACE. */
1592 	le16 size;		/* Size in bytes of the ACE. */
1593 /*  4*/	ACCESS_MASK mask;	/* Access mask associated with the ACE. */
1594 
1595 /*  8*/	OBJECT_ACE_FLAGS object_flags;	/* Flags describing the object ACE. */
1596 /* 12*/	GUID object_type;
1597 /* 28*/	GUID inherited_object_type;
1598 
1599 /* 44*/	SID sid;		/* The SID associated with the ACE. */
1600 } __attribute__ ((__packed__)) ACCESS_ALLOWED_OBJECT_ACE,
1601 			       ACCESS_DENIED_OBJECT_ACE,
1602 			       SYSTEM_AUDIT_OBJECT_ACE,
1603 			       SYSTEM_ALARM_OBJECT_ACE;
1604 
1605 /*
1606  * An ACL is an access-control list (ACL).
1607  * An ACL starts with an ACL header structure, which specifies the size of
1608  * the ACL and the number of ACEs it contains. The ACL header is followed by
1609  * zero or more access control entries (ACEs). The ACL as well as each ACE
1610  * are aligned on 4-byte boundaries.
1611  */
1612 typedef struct {
1613 	u8 revision;	/* Revision of this ACL. */
1614 	u8 alignment1;
1615 	le16 size;	/* Allocated space in bytes for ACL. Includes this
1616 			   header, the ACEs and the remaining free space. */
1617 	le16 ace_count;	/* Number of ACEs in the ACL. */
1618 	le16 alignment2;
1619 /* sizeof() = 8 bytes */
1620 } __attribute__ ((__packed__)) ACL;
1621 
1622 /*
1623  * Current constants for ACLs.
1624  */
1625 typedef enum {
1626 	/* Current revision. */
1627 	ACL_REVISION		= 2,
1628 	ACL_REVISION_DS		= 4,
1629 
1630 	/* History of revisions. */
1631 	ACL_REVISION1		= 1,
1632 	MIN_ACL_REVISION	= 2,
1633 	ACL_REVISION2		= 2,
1634 	ACL_REVISION3		= 3,
1635 	ACL_REVISION4		= 4,
1636 	MAX_ACL_REVISION	= 4,
1637 } ACL_CONSTANTS;
1638 
1639 /*
1640  * The security descriptor control flags (16-bit).
1641  *
1642  * SE_OWNER_DEFAULTED - This boolean flag, when set, indicates that the SID
1643  *	pointed to by the Owner field was provided by a defaulting mechanism
1644  *	rather than explicitly provided by the original provider of the
1645  *	security descriptor.  This may affect the treatment of the SID with
1646  *	respect to inheritance of an owner.
1647  *
1648  * SE_GROUP_DEFAULTED - This boolean flag, when set, indicates that the SID in
1649  *	the Group field was provided by a defaulting mechanism rather than
1650  *	explicitly provided by the original provider of the security
1651  *	descriptor.  This may affect the treatment of the SID with respect to
1652  *	inheritance of a primary group.
1653  *
1654  * SE_DACL_PRESENT - This boolean flag, when set, indicates that the security
1655  *	descriptor contains a discretionary ACL.  If this flag is set and the
1656  *	Dacl field of the SECURITY_DESCRIPTOR is null, then a null ACL is
1657  *	explicitly being specified.
1658  *
1659  * SE_DACL_DEFAULTED - This boolean flag, when set, indicates that the ACL
1660  *	pointed to by the Dacl field was provided by a defaulting mechanism
1661  *	rather than explicitly provided by the original provider of the
1662  *	security descriptor.  This may affect the treatment of the ACL with
1663  *	respect to inheritance of an ACL.  This flag is ignored if the
1664  *	DaclPresent flag is not set.
1665  *
1666  * SE_SACL_PRESENT - This boolean flag, when set,  indicates that the security
1667  *	descriptor contains a system ACL pointed to by the Sacl field.  If this
1668  *	flag is set and the Sacl field of the SECURITY_DESCRIPTOR is null, then
1669  *	an empty (but present) ACL is being specified.
1670  *
1671  * SE_SACL_DEFAULTED - This boolean flag, when set, indicates that the ACL
1672  *	pointed to by the Sacl field was provided by a defaulting mechanism
1673  *	rather than explicitly provided by the original provider of the
1674  *	security descriptor.  This may affect the treatment of the ACL with
1675  *	respect to inheritance of an ACL.  This flag is ignored if the
1676  *	SaclPresent flag is not set.
1677  *
1678  * SE_SELF_RELATIVE - This boolean flag, when set, indicates that the security
1679  *	descriptor is in self-relative form.  In this form, all fields of the
1680  *	security descriptor are contiguous in memory and all pointer fields are
1681  *	expressed as offsets from the beginning of the security descriptor.
1682  */
1683 enum {
1684 	SE_OWNER_DEFAULTED		= cpu_to_le16(0x0001),
1685 	SE_GROUP_DEFAULTED		= cpu_to_le16(0x0002),
1686 	SE_DACL_PRESENT			= cpu_to_le16(0x0004),
1687 	SE_DACL_DEFAULTED		= cpu_to_le16(0x0008),
1688 
1689 	SE_SACL_PRESENT			= cpu_to_le16(0x0010),
1690 	SE_SACL_DEFAULTED		= cpu_to_le16(0x0020),
1691 
1692 	SE_DACL_AUTO_INHERIT_REQ	= cpu_to_le16(0x0100),
1693 	SE_SACL_AUTO_INHERIT_REQ	= cpu_to_le16(0x0200),
1694 	SE_DACL_AUTO_INHERITED		= cpu_to_le16(0x0400),
1695 	SE_SACL_AUTO_INHERITED		= cpu_to_le16(0x0800),
1696 
1697 	SE_DACL_PROTECTED		= cpu_to_le16(0x1000),
1698 	SE_SACL_PROTECTED		= cpu_to_le16(0x2000),
1699 	SE_RM_CONTROL_VALID		= cpu_to_le16(0x4000),
1700 	SE_SELF_RELATIVE		= cpu_to_le16(0x8000)
1701 } __attribute__ ((__packed__));
1702 
1703 typedef le16 SECURITY_DESCRIPTOR_CONTROL;
1704 
1705 /*
1706  * Self-relative security descriptor. Contains the owner and group SIDs as well
1707  * as the sacl and dacl ACLs inside the security descriptor itself.
1708  */
1709 typedef struct {
1710 	u8 revision;	/* Revision level of the security descriptor. */
1711 	u8 alignment;
1712 	SECURITY_DESCRIPTOR_CONTROL control; /* Flags qualifying the type of
1713 			   the descriptor as well as the following fields. */
1714 	le32 owner;	/* Byte offset to a SID representing an object's
1715 			   owner. If this is NULL, no owner SID is present in
1716 			   the descriptor. */
1717 	le32 group;	/* Byte offset to a SID representing an object's
1718 			   primary group. If this is NULL, no primary group
1719 			   SID is present in the descriptor. */
1720 	le32 sacl;	/* Byte offset to a system ACL. Only valid, if
1721 			   SE_SACL_PRESENT is set in the control field. If
1722 			   SE_SACL_PRESENT is set but sacl is NULL, a NULL ACL
1723 			   is specified. */
1724 	le32 dacl;	/* Byte offset to a discretionary ACL. Only valid, if
1725 			   SE_DACL_PRESENT is set in the control field. If
1726 			   SE_DACL_PRESENT is set but dacl is NULL, a NULL ACL
1727 			   (unconditionally granting access) is specified. */
1728 /* sizeof() = 0x14 bytes */
1729 } __attribute__ ((__packed__)) SECURITY_DESCRIPTOR_RELATIVE;
1730 
1731 /*
1732  * Absolute security descriptor. Does not contain the owner and group SIDs, nor
1733  * the sacl and dacl ACLs inside the security descriptor. Instead, it contains
1734  * pointers to these structures in memory. Obviously, absolute security
1735  * descriptors are only useful for in memory representations of security
1736  * descriptors. On disk, a self-relative security descriptor is used.
1737  */
1738 typedef struct {
1739 	u8 revision;	/* Revision level of the security descriptor. */
1740 	u8 alignment;
1741 	SECURITY_DESCRIPTOR_CONTROL control;	/* Flags qualifying the type of
1742 			   the descriptor as well as the following fields. */
1743 	SID *owner;	/* Points to a SID representing an object's owner. If
1744 			   this is NULL, no owner SID is present in the
1745 			   descriptor. */
1746 	SID *group;	/* Points to a SID representing an object's primary
1747 			   group. If this is NULL, no primary group SID is
1748 			   present in the descriptor. */
1749 	ACL *sacl;	/* Points to a system ACL. Only valid, if
1750 			   SE_SACL_PRESENT is set in the control field. If
1751 			   SE_SACL_PRESENT is set but sacl is NULL, a NULL ACL
1752 			   is specified. */
1753 	ACL *dacl;	/* Points to a discretionary ACL. Only valid, if
1754 			   SE_DACL_PRESENT is set in the control field. If
1755 			   SE_DACL_PRESENT is set but dacl is NULL, a NULL ACL
1756 			   (unconditionally granting access) is specified. */
1757 } __attribute__ ((__packed__)) SECURITY_DESCRIPTOR;
1758 
1759 /*
1760  * Current constants for security descriptors.
1761  */
1762 typedef enum {
1763 	/* Current revision. */
1764 	SECURITY_DESCRIPTOR_REVISION	= 1,
1765 	SECURITY_DESCRIPTOR_REVISION1	= 1,
1766 
1767 	/* The sizes of both the absolute and relative security descriptors is
1768 	   the same as pointers, at least on ia32 architecture are 32-bit. */
1769 	SECURITY_DESCRIPTOR_MIN_LENGTH	= sizeof(SECURITY_DESCRIPTOR),
1770 } SECURITY_DESCRIPTOR_CONSTANTS;
1771 
1772 /*
1773  * Attribute: Security descriptor (0x50). A standard self-relative security
1774  * descriptor.
1775  *
1776  * NOTE: Can be resident or non-resident.
1777  * NOTE: Not used in NTFS 3.0+, as security descriptors are stored centrally
1778  * in FILE_Secure and the correct descriptor is found using the security_id
1779  * from the standard information attribute.
1780  */
1781 typedef SECURITY_DESCRIPTOR_RELATIVE SECURITY_DESCRIPTOR_ATTR;
1782 
1783 /*
1784  * On NTFS 3.0+, all security descriptors are stored in FILE_Secure. Only one
1785  * referenced instance of each unique security descriptor is stored.
1786  *
1787  * FILE_Secure contains no unnamed data attribute, i.e. it has zero length. It
1788  * does, however, contain two indexes ($SDH and $SII) as well as a named data
1789  * stream ($SDS).
1790  *
1791  * Every unique security descriptor is assigned a unique security identifier
1792  * (security_id, not to be confused with a SID). The security_id is unique for
1793  * the NTFS volume and is used as an index into the $SII index, which maps
1794  * security_ids to the security descriptor's storage location within the $SDS
1795  * data attribute. The $SII index is sorted by ascending security_id.
1796  *
1797  * A simple hash is computed from each security descriptor. This hash is used
1798  * as an index into the $SDH index, which maps security descriptor hashes to
1799  * the security descriptor's storage location within the $SDS data attribute.
1800  * The $SDH index is sorted by security descriptor hash and is stored in a B+
1801  * tree. When searching $SDH (with the intent of determining whether or not a
1802  * new security descriptor is already present in the $SDS data stream), if a
1803  * matching hash is found, but the security descriptors do not match, the
1804  * search in the $SDH index is continued, searching for a next matching hash.
1805  *
1806  * When a precise match is found, the security_id coresponding to the security
1807  * descriptor in the $SDS attribute is read from the found $SDH index entry and
1808  * is stored in the $STANDARD_INFORMATION attribute of the file/directory to
1809  * which the security descriptor is being applied. The $STANDARD_INFORMATION
1810  * attribute is present in all base mft records (i.e. in all files and
1811  * directories).
1812  *
1813  * If a match is not found, the security descriptor is assigned a new unique
1814  * security_id and is added to the $SDS data attribute. Then, entries
1815  * referencing the this security descriptor in the $SDS data attribute are
1816  * added to the $SDH and $SII indexes.
1817  *
1818  * Note: Entries are never deleted from FILE_Secure, even if nothing
1819  * references an entry any more.
1820  */
1821 
1822 /*
1823  * This header precedes each security descriptor in the $SDS data stream.
1824  * This is also the index entry data part of both the $SII and $SDH indexes.
1825  */
1826 typedef struct {
1827 	le32 hash;	  /* Hash of the security descriptor. */
1828 	le32 security_id; /* The security_id assigned to the descriptor. */
1829 	le64 offset;	  /* Byte offset of this entry in the $SDS stream. */
1830 	le32 length;	  /* Size in bytes of this entry in $SDS stream. */
1831 } __attribute__ ((__packed__)) SECURITY_DESCRIPTOR_HEADER;
1832 
1833 /*
1834  * The $SDS data stream contains the security descriptors, aligned on 16-byte
1835  * boundaries, sorted by security_id in a B+ tree. Security descriptors cannot
1836  * cross 256kib boundaries (this restriction is imposed by the Windows cache
1837  * manager). Each security descriptor is contained in a SDS_ENTRY structure.
1838  * Also, each security descriptor is stored twice in the $SDS stream with a
1839  * fixed offset of 0x40000 bytes (256kib, the Windows cache manager's max size)
1840  * between them; i.e. if a SDS_ENTRY specifies an offset of 0x51d0, then the
1841  * the first copy of the security descriptor will be at offset 0x51d0 in the
1842  * $SDS data stream and the second copy will be at offset 0x451d0.
1843  */
1844 typedef struct {
1845 /*Ofs*/
1846 /*  0	SECURITY_DESCRIPTOR_HEADER; -- Unfolded here as gcc doesn't like
1847 				       unnamed structs. */
1848 	le32 hash;	  /* Hash of the security descriptor. */
1849 	le32 security_id; /* The security_id assigned to the descriptor. */
1850 	le64 offset;	  /* Byte offset of this entry in the $SDS stream. */
1851 	le32 length;	  /* Size in bytes of this entry in $SDS stream. */
1852 /* 20*/	SECURITY_DESCRIPTOR_RELATIVE sid; /* The self-relative security
1853 					     descriptor. */
1854 } __attribute__ ((__packed__)) SDS_ENTRY;
1855 
1856 /*
1857  * The index entry key used in the $SII index. The collation type is
1858  * COLLATION_NTOFS_ULONG.
1859  */
1860 typedef struct {
1861 	le32 security_id; /* The security_id assigned to the descriptor. */
1862 } __attribute__ ((__packed__)) SII_INDEX_KEY;
1863 
1864 /*
1865  * The index entry key used in the $SDH index. The keys are sorted first by
1866  * hash and then by security_id. The collation rule is
1867  * COLLATION_NTOFS_SECURITY_HASH.
1868  */
1869 typedef struct {
1870 	le32 hash;	  /* Hash of the security descriptor. */
1871 	le32 security_id; /* The security_id assigned to the descriptor. */
1872 } __attribute__ ((__packed__)) SDH_INDEX_KEY;
1873 
1874 /*
1875  * Attribute: Volume name (0x60).
1876  *
1877  * NOTE: Always resident.
1878  * NOTE: Present only in FILE_Volume.
1879  */
1880 typedef struct {
1881 	ntfschar name[0];	/* The name of the volume in Unicode. */
1882 } __attribute__ ((__packed__)) VOLUME_NAME;
1883 
1884 /*
1885  * Possible flags for the volume (16-bit).
1886  */
1887 enum {
1888 	VOLUME_IS_DIRTY			= cpu_to_le16(0x0001),
1889 	VOLUME_RESIZE_LOG_FILE		= cpu_to_le16(0x0002),
1890 	VOLUME_UPGRADE_ON_MOUNT		= cpu_to_le16(0x0004),
1891 	VOLUME_MOUNTED_ON_NT4		= cpu_to_le16(0x0008),
1892 
1893 	VOLUME_DELETE_USN_UNDERWAY	= cpu_to_le16(0x0010),
1894 	VOLUME_REPAIR_OBJECT_ID		= cpu_to_le16(0x0020),
1895 
1896 	VOLUME_CHKDSK_UNDERWAY		= cpu_to_le16(0x4000),
1897 	VOLUME_MODIFIED_BY_CHKDSK	= cpu_to_le16(0x8000),
1898 
1899 	VOLUME_FLAGS_MASK		= cpu_to_le16(0xc03f),
1900 
1901 	/* To make our life easier when checking if we must mount read-only. */
1902 	VOLUME_MUST_MOUNT_RO_MASK	= cpu_to_le16(0xc027),
1903 } __attribute__ ((__packed__));
1904 
1905 typedef le16 VOLUME_FLAGS;
1906 
1907 /*
1908  * Attribute: Volume information (0x70).
1909  *
1910  * NOTE: Always resident.
1911  * NOTE: Present only in FILE_Volume.
1912  * NOTE: Windows 2000 uses NTFS 3.0 while Windows NT4 service pack 6a uses
1913  *	 NTFS 1.2. I haven't personally seen other values yet.
1914  */
1915 typedef struct {
1916 	le64 reserved;		/* Not used (yet?). */
1917 	u8 major_ver;		/* Major version of the ntfs format. */
1918 	u8 minor_ver;		/* Minor version of the ntfs format. */
1919 	VOLUME_FLAGS flags;	/* Bit array of VOLUME_* flags. */
1920 } __attribute__ ((__packed__)) VOLUME_INFORMATION;
1921 
1922 /*
1923  * Attribute: Data attribute (0x80).
1924  *
1925  * NOTE: Can be resident or non-resident.
1926  *
1927  * Data contents of a file (i.e. the unnamed stream) or of a named stream.
1928  */
1929 typedef struct {
1930 	u8 data[0];		/* The file's data contents. */
1931 } __attribute__ ((__packed__)) DATA_ATTR;
1932 
1933 /*
1934  * Index header flags (8-bit).
1935  */
1936 enum {
1937 	/*
1938 	 * When index header is in an index root attribute:
1939 	 */
1940 	SMALL_INDEX = 0, /* The index is small enough to fit inside the index
1941 			    root attribute and there is no index allocation
1942 			    attribute present. */
1943 	LARGE_INDEX = 1, /* The index is too large to fit in the index root
1944 			    attribute and/or an index allocation attribute is
1945 			    present. */
1946 	/*
1947 	 * When index header is in an index block, i.e. is part of index
1948 	 * allocation attribute:
1949 	 */
1950 	LEAF_NODE  = 0, /* This is a leaf node, i.e. there are no more nodes
1951 			   branching off it. */
1952 	INDEX_NODE = 1, /* This node indexes other nodes, i.e. it is not a leaf
1953 			   node. */
1954 	NODE_MASK  = 1, /* Mask for accessing the *_NODE bits. */
1955 } __attribute__ ((__packed__));
1956 
1957 typedef u8 INDEX_HEADER_FLAGS;
1958 
1959 /*
1960  * This is the header for indexes, describing the INDEX_ENTRY records, which
1961  * follow the INDEX_HEADER. Together the index header and the index entries
1962  * make up a complete index.
1963  *
1964  * IMPORTANT NOTE: The offset, length and size structure members are counted
1965  * relative to the start of the index header structure and not relative to the
1966  * start of the index root or index allocation structures themselves.
1967  */
1968 typedef struct {
1969 	le32 entries_offset;		/* Byte offset to first INDEX_ENTRY
1970 					   aligned to 8-byte boundary. */
1971 	le32 index_length;		/* Data size of the index in bytes,
1972 					   i.e. bytes used from allocated
1973 					   size, aligned to 8-byte boundary. */
1974 	le32 allocated_size;		/* Byte size of this index (block),
1975 					   multiple of 8 bytes. */
1976 	/* NOTE: For the index root attribute, the above two numbers are always
1977 	   equal, as the attribute is resident and it is resized as needed. In
1978 	   the case of the index allocation attribute the attribute is not
1979 	   resident and hence the allocated_size is a fixed value and must
1980 	   equal the index_block_size specified by the INDEX_ROOT attribute
1981 	   corresponding to the INDEX_ALLOCATION attribute this INDEX_BLOCK
1982 	   belongs to. */
1983 	INDEX_HEADER_FLAGS flags;	/* Bit field of INDEX_HEADER_FLAGS. */
1984 	u8 reserved[3];			/* Reserved/align to 8-byte boundary. */
1985 } __attribute__ ((__packed__)) INDEX_HEADER;
1986 
1987 /*
1988  * Attribute: Index root (0x90).
1989  *
1990  * NOTE: Always resident.
1991  *
1992  * This is followed by a sequence of index entries (INDEX_ENTRY structures)
1993  * as described by the index header.
1994  *
1995  * When a directory is small enough to fit inside the index root then this
1996  * is the only attribute describing the directory. When the directory is too
1997  * large to fit in the index root, on the other hand, two additional attributes
1998  * are present: an index allocation attribute, containing sub-nodes of the B+
1999  * directory tree (see below), and a bitmap attribute, describing which virtual
2000  * cluster numbers (vcns) in the index allocation attribute are in use by an
2001  * index block.
2002  *
2003  * NOTE: The root directory (FILE_root) contains an entry for itself. Other
2004  * directories do not contain entries for themselves, though.
2005  */
2006 typedef struct {
2007 	ATTR_TYPE type;			/* Type of the indexed attribute. Is
2008 					   $FILE_NAME for directories, zero
2009 					   for view indexes. No other values
2010 					   allowed. */
2011 	COLLATION_RULE collation_rule;	/* Collation rule used to sort the
2012 					   index entries. If type is $FILE_NAME,
2013 					   this must be COLLATION_FILE_NAME. */
2014 	le32 index_block_size;		/* Size of each index block in bytes (in
2015 					   the index allocation attribute). */
2016 	u8 clusters_per_index_block;	/* Cluster size of each index block (in
2017 					   the index allocation attribute), when
2018 					   an index block is >= than a cluster,
2019 					   otherwise this will be the log of
2020 					   the size (like how the encoding of
2021 					   the mft record size and the index
2022 					   record size found in the boot sector
2023 					   work). Has to be a power of 2. */
2024 	u8 reserved[3];			/* Reserved/align to 8-byte boundary. */
2025 	INDEX_HEADER index;		/* Index header describing the
2026 					   following index entries. */
2027 } __attribute__ ((__packed__)) INDEX_ROOT;
2028 
2029 /*
2030  * Attribute: Index allocation (0xa0).
2031  *
2032  * NOTE: Always non-resident (doesn't make sense to be resident anyway!).
2033  *
2034  * This is an array of index blocks. Each index block starts with an
2035  * INDEX_BLOCK structure containing an index header, followed by a sequence of
2036  * index entries (INDEX_ENTRY structures), as described by the INDEX_HEADER.
2037  */
2038 typedef struct {
2039 /*  0	NTFS_RECORD; -- Unfolded here as gcc doesn't like unnamed structs. */
2040 	NTFS_RECORD_TYPE magic;	/* Magic is "INDX". */
2041 	le16 usa_ofs;		/* See NTFS_RECORD definition. */
2042 	le16 usa_count;		/* See NTFS_RECORD definition. */
2043 
2044 /*  8*/	sle64 lsn;		/* $LogFile sequence number of the last
2045 				   modification of this index block. */
2046 /* 16*/	leVCN index_block_vcn;	/* Virtual cluster number of the index block.
2047 				   If the cluster_size on the volume is <= the
2048 				   index_block_size of the directory,
2049 				   index_block_vcn counts in units of clusters,
2050 				   and in units of sectors otherwise. */
2051 /* 24*/	INDEX_HEADER index;	/* Describes the following index entries. */
2052 /* sizeof()= 40 (0x28) bytes */
2053 /*
2054  * When creating the index block, we place the update sequence array at this
2055  * offset, i.e. before we start with the index entries. This also makes sense,
2056  * otherwise we could run into problems with the update sequence array
2057  * containing in itself the last two bytes of a sector which would mean that
2058  * multi sector transfer protection wouldn't work. As you can't protect data
2059  * by overwriting it since you then can't get it back...
2060  * When reading use the data from the ntfs record header.
2061  */
2062 } __attribute__ ((__packed__)) INDEX_BLOCK;
2063 
2064 typedef INDEX_BLOCK INDEX_ALLOCATION;
2065 
2066 /*
2067  * The system file FILE_Extend/$Reparse contains an index named $R listing
2068  * all reparse points on the volume. The index entry keys are as defined
2069  * below. Note, that there is no index data associated with the index entries.
2070  *
2071  * The index entries are sorted by the index key file_id. The collation rule is
2072  * COLLATION_NTOFS_ULONGS. FIXME: Verify whether the reparse_tag is not the
2073  * primary key / is not a key at all. (AIA)
2074  */
2075 typedef struct {
2076 	le32 reparse_tag;	/* Reparse point type (inc. flags). */
2077 	leMFT_REF file_id;	/* Mft record of the file containing the
2078 				   reparse point attribute. */
2079 } __attribute__ ((__packed__)) REPARSE_INDEX_KEY;
2080 
2081 /*
2082  * Quota flags (32-bit).
2083  *
2084  * The user quota flags.  Names explain meaning.
2085  */
2086 enum {
2087 	QUOTA_FLAG_DEFAULT_LIMITS	= cpu_to_le32(0x00000001),
2088 	QUOTA_FLAG_LIMIT_REACHED	= cpu_to_le32(0x00000002),
2089 	QUOTA_FLAG_ID_DELETED		= cpu_to_le32(0x00000004),
2090 
2091 	QUOTA_FLAG_USER_MASK		= cpu_to_le32(0x00000007),
2092 	/* This is a bit mask for the user quota flags. */
2093 
2094 	/*
2095 	 * These flags are only present in the quota defaults index entry, i.e.
2096 	 * in the entry where owner_id = QUOTA_DEFAULTS_ID.
2097 	 */
2098 	QUOTA_FLAG_TRACKING_ENABLED	= cpu_to_le32(0x00000010),
2099 	QUOTA_FLAG_ENFORCEMENT_ENABLED	= cpu_to_le32(0x00000020),
2100 	QUOTA_FLAG_TRACKING_REQUESTED	= cpu_to_le32(0x00000040),
2101 	QUOTA_FLAG_LOG_THRESHOLD	= cpu_to_le32(0x00000080),
2102 
2103 	QUOTA_FLAG_LOG_LIMIT		= cpu_to_le32(0x00000100),
2104 	QUOTA_FLAG_OUT_OF_DATE		= cpu_to_le32(0x00000200),
2105 	QUOTA_FLAG_CORRUPT		= cpu_to_le32(0x00000400),
2106 	QUOTA_FLAG_PENDING_DELETES	= cpu_to_le32(0x00000800),
2107 };
2108 
2109 typedef le32 QUOTA_FLAGS;
2110 
2111 /*
2112  * The system file FILE_Extend/$Quota contains two indexes $O and $Q. Quotas
2113  * are on a per volume and per user basis.
2114  *
2115  * The $Q index contains one entry for each existing user_id on the volume. The
2116  * index key is the user_id of the user/group owning this quota control entry,
2117  * i.e. the key is the owner_id. The user_id of the owner of a file, i.e. the
2118  * owner_id, is found in the standard information attribute. The collation rule
2119  * for $Q is COLLATION_NTOFS_ULONG.
2120  *
2121  * The $O index contains one entry for each user/group who has been assigned
2122  * a quota on that volume. The index key holds the SID of the user_id the
2123  * entry belongs to, i.e. the owner_id. The collation rule for $O is
2124  * COLLATION_NTOFS_SID.
2125  *
2126  * The $O index entry data is the user_id of the user corresponding to the SID.
2127  * This user_id is used as an index into $Q to find the quota control entry
2128  * associated with the SID.
2129  *
2130  * The $Q index entry data is the quota control entry and is defined below.
2131  */
2132 typedef struct {
2133 	le32 version;		/* Currently equals 2. */
2134 	QUOTA_FLAGS flags;	/* Flags describing this quota entry. */
2135 	le64 bytes_used;	/* How many bytes of the quota are in use. */
2136 	sle64 change_time;	/* Last time this quota entry was changed. */
2137 	sle64 threshold;	/* Soft quota (-1 if not limited). */
2138 	sle64 limit;		/* Hard quota (-1 if not limited). */
2139 	sle64 exceeded_time;	/* How long the soft quota has been exceeded. */
2140 	SID sid;		/* The SID of the user/object associated with
2141 				   this quota entry.  Equals zero for the quota
2142 				   defaults entry (and in fact on a WinXP
2143 				   volume, it is not present at all). */
2144 } __attribute__ ((__packed__)) QUOTA_CONTROL_ENTRY;
2145 
2146 /*
2147  * Predefined owner_id values (32-bit).
2148  */
2149 enum {
2150 	QUOTA_INVALID_ID	= cpu_to_le32(0x00000000),
2151 	QUOTA_DEFAULTS_ID	= cpu_to_le32(0x00000001),
2152 	QUOTA_FIRST_USER_ID	= cpu_to_le32(0x00000100),
2153 };
2154 
2155 /*
2156  * Current constants for quota control entries.
2157  */
2158 typedef enum {
2159 	/* Current version. */
2160 	QUOTA_VERSION	= 2,
2161 } QUOTA_CONTROL_ENTRY_CONSTANTS;
2162 
2163 /*
2164  * Index entry flags (16-bit).
2165  */
2166 enum {
2167 	INDEX_ENTRY_NODE = cpu_to_le16(1), /* This entry contains a
2168 			sub-node, i.e. a reference to an index block in form of
2169 			a virtual cluster number (see below). */
2170 	INDEX_ENTRY_END  = cpu_to_le16(2), /* This signifies the last
2171 			entry in an index block.  The index entry does not
2172 			represent a file but it can point to a sub-node. */
2173 
2174 	INDEX_ENTRY_SPACE_FILLER = cpu_to_le16(0xffff), /* gcc: Force
2175 			enum bit width to 16-bit. */
2176 } __attribute__ ((__packed__));
2177 
2178 typedef le16 INDEX_ENTRY_FLAGS;
2179 
2180 /*
2181  * This the index entry header (see below).
2182  */
2183 typedef struct {
2184 /*  0*/	union {
2185 		struct { /* Only valid when INDEX_ENTRY_END is not set. */
2186 			leMFT_REF indexed_file;	/* The mft reference of the file
2187 						   described by this index
2188 						   entry. Used for directory
2189 						   indexes. */
2190 		} __attribute__ ((__packed__)) dir;
2191 		struct { /* Used for views/indexes to find the entry's data. */
2192 			le16 data_offset;	/* Data byte offset from this
2193 						   INDEX_ENTRY. Follows the
2194 						   index key. */
2195 			le16 data_length;	/* Data length in bytes. */
2196 			le32 reservedV;		/* Reserved (zero). */
2197 		} __attribute__ ((__packed__)) vi;
2198 	} __attribute__ ((__packed__)) data;
2199 /*  8*/	le16 length;		 /* Byte size of this index entry, multiple of
2200 				    8-bytes. */
2201 /* 10*/	le16 key_length;	 /* Byte size of the key value, which is in the
2202 				    index entry. It follows field reserved. Not
2203 				    multiple of 8-bytes. */
2204 /* 12*/	INDEX_ENTRY_FLAGS flags; /* Bit field of INDEX_ENTRY_* flags. */
2205 /* 14*/	le16 reserved;		 /* Reserved/align to 8-byte boundary. */
2206 /* sizeof() = 16 bytes */
2207 } __attribute__ ((__packed__)) INDEX_ENTRY_HEADER;
2208 
2209 /*
2210  * This is an index entry. A sequence of such entries follows each INDEX_HEADER
2211  * structure. Together they make up a complete index. The index follows either
2212  * an index root attribute or an index allocation attribute.
2213  *
2214  * NOTE: Before NTFS 3.0 only filename attributes were indexed.
2215  */
2216 typedef struct {
2217 /*Ofs*/
2218 /*  0	INDEX_ENTRY_HEADER; -- Unfolded here as gcc dislikes unnamed structs. */
2219 	union {
2220 		struct { /* Only valid when INDEX_ENTRY_END is not set. */
2221 			leMFT_REF indexed_file;	/* The mft reference of the file
2222 						   described by this index
2223 						   entry. Used for directory
2224 						   indexes. */
2225 		} __attribute__ ((__packed__)) dir;
2226 		struct { /* Used for views/indexes to find the entry's data. */
2227 			le16 data_offset;	/* Data byte offset from this
2228 						   INDEX_ENTRY. Follows the
2229 						   index key. */
2230 			le16 data_length;	/* Data length in bytes. */
2231 			le32 reservedV;		/* Reserved (zero). */
2232 		} __attribute__ ((__packed__)) vi;
2233 	} __attribute__ ((__packed__)) data;
2234 	le16 length;		 /* Byte size of this index entry, multiple of
2235 				    8-bytes. */
2236 	le16 key_length;	 /* Byte size of the key value, which is in the
2237 				    index entry. It follows field reserved. Not
2238 				    multiple of 8-bytes. */
2239 	INDEX_ENTRY_FLAGS flags; /* Bit field of INDEX_ENTRY_* flags. */
2240 	le16 reserved;		 /* Reserved/align to 8-byte boundary. */
2241 
2242 /* 16*/	union {		/* The key of the indexed attribute. NOTE: Only present
2243 			   if INDEX_ENTRY_END bit in flags is not set. NOTE: On
2244 			   NTFS versions before 3.0 the only valid key is the
2245 			   FILE_NAME_ATTR. On NTFS 3.0+ the following
2246 			   additional index keys are defined: */
2247 		FILE_NAME_ATTR file_name;/* $I30 index in directories. */
2248 		SII_INDEX_KEY sii;	/* $SII index in $Secure. */
2249 		SDH_INDEX_KEY sdh;	/* $SDH index in $Secure. */
2250 		GUID object_id;		/* $O index in FILE_Extend/$ObjId: The
2251 					   object_id of the mft record found in
2252 					   the data part of the index. */
2253 		REPARSE_INDEX_KEY reparse;	/* $R index in
2254 						   FILE_Extend/$Reparse. */
2255 		SID sid;		/* $O index in FILE_Extend/$Quota:
2256 					   SID of the owner of the user_id. */
2257 		le32 owner_id;		/* $Q index in FILE_Extend/$Quota:
2258 					   user_id of the owner of the quota
2259 					   control entry in the data part of
2260 					   the index. */
2261 	} __attribute__ ((__packed__)) key;
2262 	/* The (optional) index data is inserted here when creating. */
2263 	// leVCN vcn;	/* If INDEX_ENTRY_NODE bit in flags is set, the last
2264 	//		   eight bytes of this index entry contain the virtual
2265 	//		   cluster number of the index block that holds the
2266 	//		   entries immediately preceding the current entry (the
2267 	//		   vcn references the corresponding cluster in the data
2268 	//		   of the non-resident index allocation attribute). If
2269 	//		   the key_length is zero, then the vcn immediately
2270 	//		   follows the INDEX_ENTRY_HEADER. Regardless of
2271 	//		   key_length, the address of the 8-byte boundary
2272 	//		   aligned vcn of INDEX_ENTRY{_HEADER} *ie is given by
2273 	//		   (char*)ie + le16_to_cpu(ie*)->length) - sizeof(VCN),
2274 	//		   where sizeof(VCN) can be hardcoded as 8 if wanted. */
2275 } __attribute__ ((__packed__)) INDEX_ENTRY;
2276 
2277 /*
2278  * Attribute: Bitmap (0xb0).
2279  *
2280  * Contains an array of bits (aka a bitfield).
2281  *
2282  * When used in conjunction with the index allocation attribute, each bit
2283  * corresponds to one index block within the index allocation attribute. Thus
2284  * the number of bits in the bitmap * index block size / cluster size is the
2285  * number of clusters in the index allocation attribute.
2286  */
2287 typedef struct {
2288 	u8 bitmap[0];			/* Array of bits. */
2289 } __attribute__ ((__packed__)) BITMAP_ATTR;
2290 
2291 /*
2292  * The reparse point tag defines the type of the reparse point. It also
2293  * includes several flags, which further describe the reparse point.
2294  *
2295  * The reparse point tag is an unsigned 32-bit value divided in three parts:
2296  *
2297  * 1. The least significant 16 bits (i.e. bits 0 to 15) specifiy the type of
2298  *    the reparse point.
2299  * 2. The 13 bits after this (i.e. bits 16 to 28) are reserved for future use.
2300  * 3. The most significant three bits are flags describing the reparse point.
2301  *    They are defined as follows:
2302  *	bit 29: Name surrogate bit. If set, the filename is an alias for
2303  *		another object in the system.
2304  *	bit 30: High-latency bit. If set, accessing the first byte of data will
2305  *		be slow. (E.g. the data is stored on a tape drive.)
2306  *	bit 31: Microsoft bit. If set, the tag is owned by Microsoft. User
2307  *		defined tags have to use zero here.
2308  *
2309  * These are the predefined reparse point tags:
2310  */
2311 enum {
2312 	IO_REPARSE_TAG_IS_ALIAS		= cpu_to_le32(0x20000000),
2313 	IO_REPARSE_TAG_IS_HIGH_LATENCY	= cpu_to_le32(0x40000000),
2314 	IO_REPARSE_TAG_IS_MICROSOFT	= cpu_to_le32(0x80000000),
2315 
2316 	IO_REPARSE_TAG_RESERVED_ZERO	= cpu_to_le32(0x00000000),
2317 	IO_REPARSE_TAG_RESERVED_ONE	= cpu_to_le32(0x00000001),
2318 	IO_REPARSE_TAG_RESERVED_RANGE	= cpu_to_le32(0x00000001),
2319 
2320 	IO_REPARSE_TAG_NSS		= cpu_to_le32(0x68000005),
2321 	IO_REPARSE_TAG_NSS_RECOVER	= cpu_to_le32(0x68000006),
2322 	IO_REPARSE_TAG_SIS		= cpu_to_le32(0x68000007),
2323 	IO_REPARSE_TAG_DFS		= cpu_to_le32(0x68000008),
2324 
2325 	IO_REPARSE_TAG_MOUNT_POINT	= cpu_to_le32(0x88000003),
2326 
2327 	IO_REPARSE_TAG_HSM		= cpu_to_le32(0xa8000004),
2328 
2329 	IO_REPARSE_TAG_SYMBOLIC_LINK	= cpu_to_le32(0xe8000000),
2330 
2331 	IO_REPARSE_TAG_VALID_VALUES	= cpu_to_le32(0xe000ffff),
2332 };
2333 
2334 /*
2335  * Attribute: Reparse point (0xc0).
2336  *
2337  * NOTE: Can be resident or non-resident.
2338  */
2339 typedef struct {
2340 	le32 reparse_tag;		/* Reparse point type (inc. flags). */
2341 	le16 reparse_data_length;	/* Byte size of reparse data. */
2342 	le16 reserved;			/* Align to 8-byte boundary. */
2343 	u8 reparse_data[0];		/* Meaning depends on reparse_tag. */
2344 } __attribute__ ((__packed__)) REPARSE_POINT;
2345 
2346 /*
2347  * Attribute: Extended attribute (EA) information (0xd0).
2348  *
2349  * NOTE: Always resident. (Is this true???)
2350  */
2351 typedef struct {
2352 	le16 ea_length;		/* Byte size of the packed extended
2353 				   attributes. */
2354 	le16 need_ea_count;	/* The number of extended attributes which have
2355 				   the NEED_EA bit set. */
2356 	le32 ea_query_length;	/* Byte size of the buffer required to query
2357 				   the extended attributes when calling
2358 				   ZwQueryEaFile() in Windows NT/2k. I.e. the
2359 				   byte size of the unpacked extended
2360 				   attributes. */
2361 } __attribute__ ((__packed__)) EA_INFORMATION;
2362 
2363 /*
2364  * Extended attribute flags (8-bit).
2365  */
2366 enum {
2367 	NEED_EA	= 0x80		/* If set the file to which the EA belongs
2368 				   cannot be interpreted without understanding
2369 				   the associates extended attributes. */
2370 } __attribute__ ((__packed__));
2371 
2372 typedef u8 EA_FLAGS;
2373 
2374 /*
2375  * Attribute: Extended attribute (EA) (0xe0).
2376  *
2377  * NOTE: Can be resident or non-resident.
2378  *
2379  * Like the attribute list and the index buffer list, the EA attribute value is
2380  * a sequence of EA_ATTR variable length records.
2381  */
2382 typedef struct {
2383 	le32 next_entry_offset;	/* Offset to the next EA_ATTR. */
2384 	EA_FLAGS flags;		/* Flags describing the EA. */
2385 	u8 ea_name_length;	/* Length of the name of the EA in bytes
2386 				   excluding the '\0' byte terminator. */
2387 	le16 ea_value_length;	/* Byte size of the EA's value. */
2388 	u8 ea_name[0];		/* Name of the EA.  Note this is ASCII, not
2389 				   Unicode and it is zero terminated. */
2390 	u8 ea_value[0];		/* The value of the EA.  Immediately follows
2391 				   the name. */
2392 } __attribute__ ((__packed__)) EA_ATTR;
2393 
2394 /*
2395  * Attribute: Property set (0xf0).
2396  *
2397  * Intended to support Native Structure Storage (NSS) - a feature removed from
2398  * NTFS 3.0 during beta testing.
2399  */
2400 typedef struct {
2401 	/* Irrelevant as feature unused. */
2402 } __attribute__ ((__packed__)) PROPERTY_SET;
2403 
2404 /*
2405  * Attribute: Logged utility stream (0x100).
2406  *
2407  * NOTE: Can be resident or non-resident.
2408  *
2409  * Operations on this attribute are logged to the journal ($LogFile) like
2410  * normal metadata changes.
2411  *
2412  * Used by the Encrypting File System (EFS). All encrypted files have this
2413  * attribute with the name $EFS.
2414  */
2415 typedef struct {
2416 	/* Can be anything the creator chooses. */
2417 	/* EFS uses it as follows: */
2418 	// FIXME: Type this info, verifying it along the way. (AIA)
2419 } __attribute__ ((__packed__)) LOGGED_UTILITY_STREAM, EFS_ATTR;
2420 
2421 #endif /* _LINUX_NTFS_LAYOUT_H */
2422