xref: /reactos/drivers/filesystems/fs_rec/ffs.h (revision 2196a06f)
1 /*
2  * COPYRIGHT:        See COPYING in the top level directory
3  * PROJECT:          ReactOS File System Recognizer
4  * FILE:             drivers/filesystems/fs_rec/ffs.h
5  * PURPOSE:          FFS Header File
6  * PROGRAMMER:       Peter Hater
7  *                   Pierre Schweitzer (pierre@reactos.org)
8  */
9 
10 #include <pshpack1.h>
11 
12 /*
13  * The path name on which the file system is mounted is maintained
14  * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
15  * the super block for this name.
16  */
17 #define	MAXMNTLEN	468
18 
19 /*
20  * The volume name for this filesystem is maintained in fs_volname.
21  * MAXVOLLEN defines the length of the buffer allocated.
22  * This space used to be part of of fs_fsmnt.
23  */
24 #define MAXVOLLEN	32
25 
26 /*
27  * Unused value currently, FreeBSD compat.
28  */
29 #define FSMAXSNAP 20
30 
31 /*
32  * There is a 128-byte region in the superblock reserved for in-core
33  * pointers to summary information. Originally this included an array
34  * of pointers to blocks of struct csum; now there are just four
35  * pointers and the remaining space is padded with fs_ocsp[].
36  * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
37  * is taken away to point to a contiguous array of struct csum for
38  * all cylinder groups; a second (fs_maxcluster) points to an array
39  * of cluster sizes that is computed as cylinder groups are inspected;
40  * the third (fs_contigdirs) points to an array that tracks the
41  * creation of new directories; and the fourth (fs_active) is used
42  * by snapshots.
43  */
44 #define	NOCSPTRS	((128 / sizeof(void *)) - 4)
45 
46 /*
47  * Per cylinder group information; summarized in blocks allocated
48  * from first cylinder group data blocks.  These blocks have to be
49  * read in from fs_csaddr (size fs_cssize) in addition to the
50  * super block.
51  */
52 struct csum {
53 	INT32	cs_ndir;		/* number of directories */
54 	INT32	cs_nbfree;		/* number of free blocks */
55 	INT32	cs_nifree;		/* number of free inodes */
56 	INT32	cs_nffree;		/* number of free frags */
57 };
58 
59 struct csum_total {
60 	INT64   cs_ndir;		/* number of directories */
61 	INT64   cs_nbfree;		/* number of free blocks */
62 	INT64   cs_nifree;		/* number of free inodes */
63 	INT64   cs_nffree;		/* number of free frags */
64 	INT64   cs_spare[4];	/* future expansion */
65 };
66 
67 /*
68  * Super block for an FFS file system in memory.
69  */
70 typedef struct fs {
71 	INT32	 fs_firstfield;		/* historic file system linked list, */
72 	INT32	 fs_unused_1;		/*     used for incore super blocks */
73 	INT32    fs_sblkno;		/* addr of super-block in filesys */
74 	INT32    fs_cblkno;		/* offset of cyl-block in filesys */
75 	INT32    fs_iblkno;		/* offset of inode-blocks in filesys */
76 	INT32    fs_dblkno;		/* offset of first data after cg */
77 	INT32	 fs_old_cgoffset;	/* cylinder group offset in cylinder */
78 	INT32	 fs_old_cgmask;		/* used to calc mod fs_ntrak */
79 	INT32	 fs_old_time;		/* last time written */
80 	INT32	 fs_old_size;		/* number of blocks in fs */
81 	INT32	 fs_old_dsize;		/* number of data blocks in fs */
82 	INT32	 fs_ncg;		/* number of cylinder groups */
83 	INT32	 fs_bsize;		/* size of basic blocks in fs */
84 	INT32	 fs_fsize;		/* size of frag blocks in fs */
85 	INT32	 fs_frag;		/* number of frags in a block in fs */
86 /* these are configuration parameters */
87 	INT32	 fs_minfree;		/* minimum percentage of free blocks */
88 	INT32	 fs_old_rotdelay;	/* num of ms for optimal next block */
89 	INT32	 fs_old_rps;		/* disk revolutions per second */
90 /* these fields can be computed from the others */
91 	INT32	 fs_bmask;		/* ``blkoff'' calc of blk offsets */
92 	INT32	 fs_fmask;		/* ``fragoff'' calc of frag offsets */
93 	INT32	 fs_bshift;		/* ``lblkno'' calc of logical blkno */
94 	INT32	 fs_fshift;		/* ``numfrags'' calc number of frags */
95 /* these are configuration parameters */
96 	INT32	 fs_maxcontig;		/* max number of contiguous blks */
97 	INT32	 fs_maxbpg;		/* max number of blks per cyl group */
98 /* these fields can be computed from the others */
99 	INT32	 fs_fragshift;		/* block to frag shift */
100 	INT32	 fs_fsbtodb;		/* fsbtodb and dbtofsb shift constant */
101 	INT32	 fs_sbsize;		/* actual size of super block */
102 	INT32	 fs_spare1[2];		/* old fs_csmask */
103 					/* old fs_csshift */
104 	INT32	 fs_nindir;		/* value of NINDIR */
105 	INT32	 fs_inopb;		/* value of INOPB */
106 	INT32	 fs_old_nspf;		/* value of NSPF */
107 /* yet another configuration parameter */
108 	INT32	 fs_optim;		/* optimization preference, see below */
109 /* these fields are derived from the hardware */
110 	INT32	 fs_old_npsect;		/* # sectors/track including spares */
111 	INT32	 fs_old_interleave;	/* hardware sector interleave */
112 	INT32	 fs_old_trackskew;	/* sector 0 skew, per track */
113 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
114 	INT32	 fs_id[2];		/* unique file system id */
115 /* sizes determined by number of cylinder groups and their sizes */
116 	INT32    fs_old_csaddr;		/* blk addr of cyl grp summary area */
117 	INT32	 fs_cssize;		/* size of cyl grp summary area */
118 	INT32	 fs_cgsize;		/* cylinder group size */
119 /* these fields are derived from the hardware */
120 	INT32	 fs_spare2;		/* old fs_ntrak */
121 	INT32	 fs_old_nsect;		/* sectors per track */
122 	INT32	 fs_old_spc;		/* sectors per cylinder */
123 	INT32	 fs_old_ncyl;		/* cylinders in file system */
124 	INT32	 fs_old_cpg;		/* cylinders per group */
125 	INT32	 fs_ipg;		/* inodes per group */
126 	INT32	 fs_fpg;		/* blocks per group * fs_frag */
127 /* this data must be re-computed after crashes */
128 	struct	csum fs_old_cstotal;	/* cylinder summary information */
129 /* these fields are cleared at mount time */
130 	INT8	 fs_fmod;		/* super block modified flag */
131 	INT8	 fs_clean;		/* file system is clean flag */
132 	INT8	 fs_ronly;		/* mounted read-only flag */
133 	UINT8	 fs_old_flags;		/* see FS_ flags below */
134 	UCHAR	 fs_fsmnt[MAXMNTLEN];	/* name mounted on */
135 	UCHAR    fs_volname[MAXVOLLEN];	/* volume name */
136 	UINT64   fs_swuid;		/* system-wide uid */
137 	INT32	 fs_pad;
138 /* these fields retain the current block allocation info */
139 	INT32	 fs_cgrotor;		/* last cg searched (UNUSED) */
140 	void 	*fs_ocsp[NOCSPTRS];	/* padding; was list of fs_cs buffers */
141 	UINT8   *fs_contigdirs;	/* # of contiguously allocated dirs */
142 	struct csum *fs_csp;		/* cg summary info buffer for fs_cs */
143 	INT32	*fs_maxcluster;		/* max cluster in each cyl group */
144 	INT32	*fs_active;		/* used by snapshots to track fs */
145 	INT32	 fs_old_cpc;		/* cyl per cycle in postbl */
146 /* this area is otherwise allocated unless fs_old_flags & FS_FLAGS_UPDATED */
147 	INT32	 fs_maxbsize;		/* maximum blocking factor permitted */
148 	INT64	 fs_sparecon64[17];	/* old rotation block list head */
149 	INT64	 fs_sblockloc;		/* byte offset of standard superblock */
150 	struct	csum_total fs_cstotal;	/* cylinder summary information */
151 	INT64    fs_time;		/* last time written */
152 	INT64	 fs_size;		/* number of blocks in fs */
153 	INT64	 fs_dsize;		/* number of data blocks in fs */
154 	INT64    fs_csaddr;		/* blk addr of cyl grp summary area */
155 	INT64	 fs_pendingblocks;	/* blocks in process of being freed */
156 	INT32	 fs_pendinginodes;	/* inodes in process of being freed */
157 	INT32	 fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */
158 /* back to stuff that has been around a while */
159 	INT32	 fs_avgfilesize;	/* expected average file size */
160 	INT32	 fs_avgfpdir;		/* expected # of files per directory */
161 	INT32	 fs_save_cgsize;	/* save real cg size to use fs_bsize */
162 	INT32	 fs_sparecon32[26];	/* reserved for future constants */
163 	INT32    fs_flags;		/* see FS_ flags below */
164 /* back to stuff that has been around a while (again) */
165 	INT32	 fs_contigsumsize;	/* size of cluster summary array */
166 	INT32	 fs_maxsymlinklen;	/* max length of an internal symlink */
167 	INT32	 fs_old_inodefmt;	/* format of on-disk inodes */
168 	UINT64   fs_maxfilesize;	/* maximum representable file size */
169 	INT64	 fs_qbmask;		/* ~fs_bmask for use with 64-bit size */
170 	INT64	 fs_qfmask;		/* ~fs_fmask for use with 64-bit size */
171 	INT32	 fs_state;		/* validate fs_clean field (UNUSED) */
172 	INT32	 fs_old_postblformat;	/* format of positional layout tables */
173 	INT32	 fs_old_nrpos;		/* number of rotational positions */
174 	INT32    fs_spare5[2];		/* old fs_postbloff */
175 					/* old fs_rotbloff */
176 	INT32	 fs_magic;		/* magic number */
177 } FFSD_SUPER_BLOCK, *PFFSD_SUPER_BLOCK;
178 
179 #define	MAXPARTITIONS		16	/* number of partitions */
180 #define	NDDATA 5
181 #define	NSPARE 5
182 
183 typedef struct disklabel {
184 	UINT32 d_magic;		/* the magic number */
185 	UINT16 d_type;		/* drive type */
186 	UINT16 d_subtype;		/* controller/d_type specific */
187 	char	  d_typename[16];	/* type name, e.g. "eagle" */
188 
189 	/*
190 	 * d_packname contains the pack identifier and is returned when
191 	 * the disklabel is read off the disk or in-core copy.
192 	 * d_boot0 and d_boot1 are the (optional) names of the
193 	 * primary (block 0) and secondary (block 1-15) bootstraps
194 	 * as found in /usr/mdec.  These are returned when using
195 	 * getdiskbyname(3) to retrieve the values from /etc/disktab.
196 	 */
197 	union {
198 		char	un_d_packname[16];	/* pack identifier */
199 		struct {
200 			char *un_d_boot0;	/* primary bootstrap name */
201 			char *un_d_boot1;	/* secondary bootstrap name */
202 		} un_b;
203 	} d_un;
204 
205 			/* disk geometry: */
206 	UINT32 d_secsize;		/* # of bytes per sector */
207 	UINT32 d_nsectors;		/* # of data sectors per track */
208 	UINT32 d_ntracks;		/* # of tracks per cylinder */
209 	UINT32 d_ncylinders;		/* # of data cylinders per unit */
210 	UINT32 d_secpercyl;		/* # of data sectors per cylinder */
211 	UINT32 d_secperunit;		/* # of data sectors per unit */
212 
213 	/*
214 	 * Spares (bad sector replacements) below are not counted in
215 	 * d_nsectors or d_secpercyl.  Spare sectors are assumed to
216 	 * be physical sectors which occupy space at the end of each
217 	 * track and/or cylinder.
218 	 */
219 	UINT16 d_sparespertrack;	/* # of spare sectors per track */
220 	UINT16 d_sparespercyl;	/* # of spare sectors per cylinder */
221 	/*
222 	 * Alternative cylinders include maintenance, replacement,
223 	 * configuration description areas, etc.
224 	 */
225 	UINT32 d_acylinders;		/* # of alt. cylinders per unit */
226 
227 			/* hardware characteristics: */
228 	/*
229 	 * d_interleave, d_trackskew and d_cylskew describe perturbations
230 	 * in the media format used to compensate for a slow controller.
231 	 * Interleave is physical sector interleave, set up by the
232 	 * formatter or controller when formatting.  When interleaving is
233 	 * in use, logically adjacent sectors are not physically
234 	 * contiguous, but instead are separated by some number of
235 	 * sectors.  It is specified as the ratio of physical sectors
236 	 * traversed per logical sector.  Thus an interleave of 1:1
237 	 * implies contiguous layout, while 2:1 implies that logical
238 	 * sector 0 is separated by one sector from logical sector 1.
239 	 * d_trackskew is the offset of sector 0 on track N relative to
240 	 * sector 0 on track N-1 on the same cylinder.  Finally, d_cylskew
241 	 * is the offset of sector 0 on cylinder N relative to sector 0
242 	 * on cylinder N-1.
243 	 */
244 	UINT16 d_rpm;		/* rotational speed */
245 	UINT16 d_interleave;		/* hardware sector interleave */
246 	UINT16 d_trackskew;		/* sector 0 skew, per track */
247 	UINT16 d_cylskew;		/* sector 0 skew, per cylinder */
248 	UINT32 d_headswitch;		/* head switch time, usec */
249 	UINT32 d_trkseek;		/* track-to-track seek, usec */
250 	UINT32 d_flags;		/* generic flags */
251 	UINT32 d_drivedata[NDDATA];	/* drive-type specific information */
252 	UINT32 d_spare[NSPARE];	/* reserved for future use */
253 	UINT32 d_magic2;		/* the magic number (again) */
254 	UINT16 d_checksum;		/* xor of data incl. partitions */
255 
256 			/* filesystem and partition information: */
257 	UINT16 d_npartitions;	/* number of partitions in following */
258 	UINT32 d_bbsize;		/* size of boot area at sn0, bytes */
259 	UINT32 d_sbsize;		/* max size of fs superblock, bytes */
260 	struct	partition {		/* the partition table */
261 		UINT32 p_size;	/* number of sectors in partition */
262 		UINT32 p_offset;	/* starting sector */
263 		union {
264 			UINT32 fsize; /* FFS, ADOS:
265 					    filesystem basic fragment size */
266 			UINT32 cdsession; /* ISO9660: session offset */
267 		} __partition_u2;
268 		UINT8 p_fstype;	/* filesystem type, see below */
269 		UINT8 p_frag;	/* filesystem fragments per block */
270 		union {
271 			UINT16 cpg;	/* UFS: FS cylinders per group */
272 			UINT16 sgs;	/* LFS: FS segment shift */
273 		} __partition_u1;
274 	} d_partitions[MAXPARTITIONS];	/* actually may be more */
275 } FFSD_DISKLABEL, *PFFSD_DISKLABEL;
276 #include <poppack.h>
277 
278 C_ASSERT(FIELD_OFFSET(FFSD_SUPER_BLOCK, fs_cgsize) == 160);
279 C_ASSERT(FIELD_OFFSET(FFSD_SUPER_BLOCK, fs_fmod) == 208);
280 C_ASSERT(FIELD_OFFSET(FFSD_SUPER_BLOCK, fs_ocsp) == 728);
281 
282 #define SBLOCK_UFS1     8192
283 #define SBLOCK_UFS2    65536
284 
285 #define SBLOCKSIZE      8192
286 
287 /*
288  * File system identification
289  */
290 #define	FS_UFS1_MAGIC	0x011954	/* UFS1 fast file system magic number */
291 #define	FS_UFS2_MAGIC	0x19540119	/* UFS2 fast file system magic number */
292 
293 #define	DISKMAGIC	((UINT32)0x82564557)	/* The disk magic number */
294 
295 #define	LABELSECTOR		1	/* sector containing label */
296 
297 #define	FS_BSDFFS	7		/* 4.2BSD fast file system */
298