xref: /openbmc/linux/fs/ntfs/layout.h (revision 5086ea4b)
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  				   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   * 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