1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #ifndef _SYS_FS_PC_FS_H 27 #define _SYS_FS_PC_FS_H 28 29 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 #include <sys/thread.h> 32 33 #ifdef __cplusplus 34 extern "C" { 35 #endif 36 37 typedef uint16_t pc_cluster16_t; 38 typedef uint32_t pc_cluster32_t; 39 40 /* 41 * PC (MSDOS) compatible virtual file system. 42 * 43 * A main goal of the implementation was to maintain statelessness 44 * except while files are open. Thus mounting and unmounting merely 45 * declared the file system name. The user may change disks at almost 46 * any time without concern (just like the PC). It is assumed that when 47 * files are open for writing the disk access light will be on, as a 48 * warning not to change disks. The implementation must, however, detect 49 * disk change and recover gracefully. It does this by comparing the 50 * in core entry for a directory to the on disk entry whenever a directory 51 * is searched. If a discrepancy is found active directories become root and 52 * active files are marked invalid. 53 * 54 * There are only two type of nodes on the PC file system; files and 55 * directories. These are represented by two separate vnode op vectors, 56 * and they are kept in two separate tables. Files are known by the 57 * disk block number and block (cluster) offset of the files directory 58 * entry. Directories are known by the starting cluster number. 59 * 60 * The file system is locked for during each user operation. This is 61 * done to simplify disk verification error conditions. 62 * 63 * Notes on FAT32 support 64 * ---------------------- 65 * The basic difference between FAT32 and FAT16 is that cluster numbers are now 66 * 32-bit instead of 16-bit. The FAT is thus an array of 32-bit cluster numbers, 67 * and because of this the cluster size can be much smaller on a large disk 68 * (4k, say, on a 1 Gig drive instead of 16k). Unfortunately, the FAT is not 69 * the only place cluster numbers are stored - the starting cluster is stored 70 * in the directory entry for a file, and of course it's only 16-bit. Luckily, 71 * there's a 16-bit OS/2 Extended Attribute field that is now used to store the 72 * upper 16-bits of the starting cluster number. 73 * 74 * Most of the FAT32 changes to pcfs are under 'if it's FAT32' to minimize the 75 * effect on non-FAT32 filesystems (and still share the code), except for the 76 * starting cluster changes. It seemed easier to make common functions to 77 * handle that. 78 * 79 * Other changes: 80 * 81 * 1. FAT32 partitions are indicated by partition types 0xB and 0xC. 82 * 2. The boot sector is now 2 sectors, to make room for FAT32 extensions. 83 * 3. The root directory is no longer stored in a fixed location. Its' 84 * starting cluster is stored in the extended boot sector. 85 * 4. "Summary information" is now stored and we need to (at least) maintain 86 * the number of free clusters or scandisk will be upset. Though the 87 * sector this info is in is pointed to by the extensions in the boot 88 * sector, the magic offset of this information is just that so 89 * far - magic. 0x1e0. 90 * 5. FAT32 can use the alternate FAT. But we don't. 91 * 92 * FAT32 also exposed a latent bug: we bread() each copy of the FAT in one 93 * big chunk. This is not good on a large FAT32 drive, such as a 1 Gig 94 * Jaz drive that has 4k clusters, since the FAT becomes 1 Meg in size and 95 * bread blocks forever. So now we read the FAT in chunks. 96 */ 97 98 /* 99 * pre-FAT32 boot sector. 100 */ 101 struct bootsec { 102 uchar_t instr[3]; 103 uchar_t version[8]; 104 uchar_t bps[2]; /* bytes per sector */ 105 uchar_t spcl; /* sectors per allocation unit */ 106 uchar_t res_sec[2]; /* reserved sectors, starting at 0 */ 107 uchar_t nfat; /* number of FATs */ 108 uchar_t rdirents[2]; /* number of root directory entries */ 109 uchar_t numsect[2]; /* old total sectors in logical image */ 110 uchar_t mediadesriptor; /* media descriptor byte */ 111 ushort_t fatsec; /* number of sectors per FAT */ 112 ushort_t spt; /* sectors per track */ 113 ushort_t nhead; /* number of heads */ 114 uint_t hiddensec; /* number of hidden sectors */ 115 uint_t totalsec; /* total sectors in logical image */ 116 }; 117 118 /* 119 * FAT32 volumes have a bigger boot sector. They include the normal 120 * boot sector. 121 */ 122 struct fat32_bootsec { 123 struct bootsec f_bs; 124 uint32_t f_fatlength; /* size of FAT */ 125 uint16_t f_flags; 126 uint8_t f_major; /* major filesystem version #? */ 127 uint8_t f_minor; /* minor filesystem version #? */ 128 uint32_t f_rootcluster; /* first cluster in root directory */ 129 uint16_t f_infosector; /* where summary info is */ 130 uint16_t f_backupboot; /* backup boot sector */ 131 uint16_t f_reserved2[6]; 132 }; 133 134 #define FAT32_FS_SIGN 0x61417272 135 #define FAT32_BOOT_FSINFO_OFF 0x1e0 136 137 /* 138 * summary information for fat32 volumes. We need to maintain fs_free_clusters 139 * or Microsoft Scandisk will be upset. 140 */ 141 struct fat32_boot_fsinfo { 142 uint32_t fs_reserved1; 143 uint32_t fs_signature; /* 0x61417272 */ 144 uint32_t fs_free_clusters; /* # free clusters. -1 if unknown */ 145 uint32_t fs_next_cluster; /* unused by pcfs */ 146 uint32_t fs_reserved2[4]; 147 }; 148 149 #define FSINFO_UNKNOWN (-1) 150 151 struct pcfs { 152 struct vfs *pcfs_vfs; /* vfs for this fs */ 153 int pcfs_flags; /* flags */ 154 int pcfs_ldrv; /* logical DOS drive number */ 155 dev_t pcfs_xdev; /* actual device that is mounted */ 156 struct vnode *pcfs_devvp; /* and a vnode for it */ 157 int pcfs_secsize; /* sector size in bytes */ 158 int pcfs_spcl; /* sectors per cluster */ 159 int pcfs_spt; /* sectors per track */ 160 int pcfs_sdshift; /* shift to convert sector into */ 161 /* DEV_BSIZE "sectors"; assume */ 162 /* pcfs_secsize is 2**n times of */ 163 /* DEV_BSIZE */ 164 int pcfs_fatsec; /* number of sec per FAT */ 165 int pcfs_numfat; /* number of FAT copies */ 166 int pcfs_rdirsec; /* number of sec in root dir */ 167 daddr_t pcfs_dosstart; /* start blkno of DOS partition */ 168 daddr_t pcfs_fatstart; /* start blkno of first FAT */ 169 daddr_t pcfs_rdirstart; /* start blkno of root dir */ 170 daddr_t pcfs_datastart; /* start blkno of data area */ 171 int pcfs_clsize; /* cluster size in bytes */ 172 int pcfs_ncluster; /* number of clusters in fs */ 173 int pcfs_entps; /* number of dir entry per sector */ 174 int pcfs_nrefs; /* number of active pcnodes */ 175 int pcfs_frefs; /* number of active file pcnodes */ 176 int pcfs_nxfrecls; /* next free cluster */ 177 uchar_t *pcfs_fatp; /* ptr to FAT data */ 178 uchar_t *pcfs_fat_changemap; /* map of changed fat data */ 179 int pcfs_fatsize; /* size of FAT data */ 180 int pcfs_fat_changemapsize; /* size of FAT changemap */ 181 time_t pcfs_fattime; /* time FAT becomes invalid */ 182 time_t pcfs_verifytime; /* time to reverify disk */ 183 kmutex_t pcfs_lock; /* per filesystem lock */ 184 kthread_id_t pcfs_owner; /* id of thread locking pcfs */ 185 int pcfs_count; /* # of pcfs locks for pcfs_owner */ 186 struct fat32_boot_fsinfo fsinfo_native; /* native fsinfo for fat32 */ 187 uint32_t f32fsinfo_sector; /* where to read/write fsinfo */ 188 struct pcfs *pcfs_nxt; /* linked list of all mounts */ 189 int pcfs_fatjustread; /* Used to flag a freshly found FAT */ 190 }; 191 192 /* 193 * flags 194 */ 195 #define PCFS_FATMOD 0x01 /* FAT has been modified */ 196 #define PCFS_LOCKED 0x02 /* fs is locked */ 197 #define PCFS_WANTED 0x04 /* locked fs is wanted */ 198 #define PCFS_FAT16 0x400 /* 16 bit FAT */ 199 #define PCFS_NOCHK 0x800 /* don't resync fat on error */ 200 #define PCFS_BOOTPART 0x1000 /* boot partition type */ 201 #define PCFS_HIDDEN 0x2000 /* show hidden files */ 202 #define PCFS_PCMCIA_NO_CIS 0x4000 /* PCMCIA psuedo floppy */ 203 #define PCFS_FOLDCASE 0x8000 /* fold all names from media to */ 204 /* lowercase */ 205 #define PCFS_FAT32 0x10000 /* 32 bit FAT */ 206 #define PCFS_IRRECOV 0x20000 /* FS was messed with during write */ 207 208 /* for compatibility */ 209 struct old_pcfs_args { 210 int secondswest; /* seconds west of Greenwich */ 211 int dsttime; /* type of dst correction */ 212 }; 213 214 struct pcfs_args { 215 int secondswest; /* seconds west of Greenwich */ 216 int dsttime; /* type of dst correction */ 217 int flags; 218 }; 219 220 /* 221 * flags for the pcfs_args 'flags' field. 222 * 223 * Note that these two macros are obsolete - do not use them. 224 */ 225 #define PCFS_MNT_HIDDEN 0x01 /* show hidden files */ 226 #define PCFS_MNT_FOLDCASE 0x02 /* fold all names from media to */ 227 /* lowercase */ 228 229 /* 230 * pcfs mount options. 231 */ 232 #define MNTOPT_PCFS_HIDDEN "hidden" 233 #define MNTOPT_PCFS_NOHIDDEN "nohidden" 234 #define MNTOPT_PCFS_FOLDCASE "foldcase" 235 #define MNTOPT_PCFS_NOFOLDCASE "nofoldcase" 236 237 /* 238 * Disk timeout value in sec. 239 * This is used to time out the in core FAT and to re-verify the disk. 240 * This should be less than the time it takes to change floppys 241 */ 242 #define PCFS_DISKTIMEOUT 2 243 244 #define VFSTOPCFS(VFSP) ((struct pcfs *)((VFSP)->vfs_data)) 245 #define PCFSTOVFS(FSP) ((FSP)->pcfs_vfs) 246 247 /* 248 * special cluster numbers in FAT 249 */ 250 #define PCF_FREECLUSTER 0x00 /* cluster is available */ 251 #define PCF_ERRORCLUSTER 0x01 /* error occurred allocating cluster */ 252 #define PCF_12BCLUSTER 0xFF0 /* 12-bit version of reserved cluster */ 253 #define PCF_RESCLUSTER 0xFFF0 /* 16-bit version of reserved cluster */ 254 #define PCF_RESCLUSTER32 0xFFFFFF0 /* 32-bit version */ 255 #define PCF_BADCLUSTER 0xFFF7 /* bad cluster, do not use */ 256 #define PCF_BADCLUSTER32 0xFFFFFF7 /* 32-bit version */ 257 #define PCF_LASTCLUSTER 0xFFF8 /* >= means last cluster in file */ 258 #define PCF_LASTCLUSTER32 0xFFFFFF8 /* 32-bit version */ 259 #define PCF_LASTCLUSTERMARK 0xFFFF /* value used to mark last cluster */ 260 #define PCF_LASTCLUSTERMARK32 0xFFFFFFF /* 32-bit version */ 261 #define PCF_FIRSTCLUSTER 2 /* first valid cluster number */ 262 263 /* 264 * file system constants 265 */ 266 #define PC_MAXFATSEC 256 /* maximum number of sectors in FAT */ 267 268 /* 269 * file system parameter macros 270 */ 271 272 #define IS_FAT32(PCFS) \ 273 (((PCFS)->pcfs_flags & PCFS_FAT32) == PCFS_FAT32) 274 275 #define IS_FAT16(PCFS) \ 276 (((PCFS)->pcfs_flags & PCFS_FAT16) == PCFS_FAT16) 277 278 #define IS_FAT12(PCFS) \ 279 (((PCFS)->pcfs_flags & (PCFS_FAT16 | PCFS_FAT32)) == 0) 280 281 #define pc_clear_fatchanges(PCFS) \ 282 bzero((PCFS)->pcfs_fat_changemap, (PCFS)->pcfs_fat_changemapsize) 283 284 #define pc_blksize(PCFS, PCP, OFF) /* file system block size */ \ 285 (((PCTOV(PCP)->v_flag & VROOT) && !IS_FAT32(PCFS)) ? \ 286 ((OFF) >= \ 287 ((PCFS)->pcfs_rdirsec & \ 288 ~((PCFS)->pcfs_spcl - 1)) * ((PCFS)->pcfs_secsize)? \ 289 ((PCFS)->pcfs_rdirsec & \ 290 ((PCFS)->pcfs_spcl - 1)) * ((PCFS)->pcfs_secsize): \ 291 (PCFS)->pcfs_clsize): \ 292 (PCFS)->pcfs_clsize) 293 294 #define pc_blkoff(PCFS, OFF) /* offset within block */ \ 295 ((int)((OFF) & ((PCFS)->pcfs_clsize - 1))) 296 297 #define pc_lblkno(PCFS, OFF) /* logical block (cluster) no */ \ 298 ((daddr_t)((OFF) / (PCFS)->pcfs_clsize)) 299 300 #define pc_dbtocl(PCFS, DB) /* disk blks to clusters */ \ 301 ((int)((DB) / (PCFS)->pcfs_spcl)) 302 303 #define pc_cltodb(PCFS, CL) /* clusters to disk blks */ \ 304 ((daddr_t)((CL) * (PCFS)->pcfs_spcl)) 305 306 #define pc_cldaddr(PCFS, CL) /* DEV_BSIZE "sector" addr for cluster */ \ 307 (((daddr_t)((PCFS)->pcfs_datastart + \ 308 ((CL) - PCF_FIRSTCLUSTER) * (PCFS)->pcfs_spcl)) << \ 309 (PCFS)->pcfs_sdshift) 310 311 #define pc_daddrcl(PCFS, DADDR) /* cluster for disk address */ \ 312 ((int)(((((DADDR) >> (PCFS)->pcfs_sdshift) - (PCFS)->pcfs_datastart) / \ 313 (PCFS)->pcfs_spcl) + 2)) 314 315 #define pc_dbdaddr(PCFS, DB) /* sector to DEV_BSIZE "sector" addr */ \ 316 ((DB) << (PCFS)->pcfs_sdshift) 317 318 #define pc_daddrdb(PCFS, DADDR) /* DEV_BSIZE "sector" addr to sector addr */ \ 319 ((DADDR) >> (PCFS)->pcfs_sdshift) 320 321 #define pc_validcl(PCFS, CL) /* check that cluster no is legit */ \ 322 ((int)(CL) >= PCF_FIRSTCLUSTER && \ 323 (int)(CL) <= (PCFS)->pcfs_ncluster) 324 325 /* 326 * external routines. 327 */ 328 extern int pc_lockfs(struct pcfs *, int, int); /* lock fs and get fat */ 329 extern void pc_unlockfs(struct pcfs *); /* ulock the fs */ 330 extern int pc_getfat(struct pcfs *); /* get fat from disk */ 331 extern void pc_invalfat(struct pcfs *); /* invalidate incore fat */ 332 extern int pc_syncfat(struct pcfs *); /* sync fat to disk */ 333 extern int pc_freeclusters(struct pcfs *); /* num free clusters in fs */ 334 extern pc_cluster32_t pc_alloccluster(struct pcfs *, int); 335 extern void pc_setcluster(struct pcfs *, pc_cluster32_t, pc_cluster32_t); 336 extern void pc_mark_fat_updated(struct pcfs *fsp, pc_cluster32_t cn); 337 extern int pc_fat_is_changed(struct pcfs *fsp, pc_cluster32_t bn); 338 339 /* 340 * debugging 341 */ 342 extern int pcfsdebuglevel; 343 #define PC_DPRINTF0(level, A) \ 344 if (pcfsdebuglevel >= level) \ 345 cmn_err(CE_CONT, (A)) 346 #define PC_DPRINTF1(level, A, B) \ 347 if (pcfsdebuglevel >= level) \ 348 cmn_err(CE_CONT, (A), (B)) 349 #define PC_DPRINTF2(level, A, B, C) \ 350 if (pcfsdebuglevel >= level) \ 351 cmn_err(CE_CONT, (A), (B), (C)) 352 #define PC_DPRINTF3(level, A, B, C, D) \ 353 if (pcfsdebuglevel >= level) \ 354 cmn_err(CE_CONT, (A), (B), (C), (D)) 355 #define PC_DPRINTF4(level, A, B, C, D, E) \ 356 if (pcfsdebuglevel >= level) \ 357 cmn_err(CE_CONT, (A), (B), (C), (D), (E)) 358 359 #ifdef __cplusplus 360 } 361 #endif 362 363 #endif /* _SYS_FS_PC_FS_H */ 364