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Annotation of dmsdos/doc/ioctl.doc, revision 1.1

1.1     ! root        1: DMSDOS ioctl commands (outdated.... newers are missing here)
        !             2: 
        !             3: *****************************************************************************
        !             4: WARNING: INFORMATION IN THIS FILE IS OUTDATED AND PARTIALLY WRONG. SEE THE
        !             5:          DMSDOS UTILITIES SOURCE CODE FOR PROGRAMMING EXAMPLES.
        !             6: 
        !             7:          When I have enough time I write better documentation.....
        !             8: *****************************************************************************
        !             9: 
        !            10: Example code:
        !            11: 
        !            12:   #include<stdio.h>
        !            13:   #include<linux/dmsdos_fs.h>
        !            14:   #include<sys/ioctl.h>
        !            15:   #include<sys/types.h>
        !            16:   #include<sys/stat.h>
        !            17:   #include<fcntl.h>
        !            18:   #include<string.h>
        !            19:   #include<errno.h>
        !            20: 
        !            21:   Dblsb dblsb;
        !            22:   int fd;
        !            23:   int ret;
        !            24:   unsigned long w[10];
        !            25:   Mdfat_entry mde;
        !            26: 
        !            27:   /* open file descriptor fd */
        !            28:   fd=open(CVF_name,O_RDONLY);
        !            29:   if(fd<0)
        !            30:   { printf("No such file or directory.\n");
        !            31:     return;
        !            32:   }
        !            33: 
        !            34: DMSDOS_GET_DBLSB:
        !            35: read DMSDOS version number and read CVF parameters in dblsb structure.
        !            36: This function also performs a version check, i.e. if the dmsdos driver in
        !            37: the kernel thinks the version number you supply in s_dcluster is too old, 
        !            38: it "or"s the returned value with 0x0f000000 and doesn't fill in the values
        !            39: for the dblsb structure.
        !            40: 
        !            41: ** Since not all DMSDOS versions support all commands, this ioctl should be
        !            42: always issued first **
        !            43: 
        !            44:   dblsb.s_dcluster=DMSDOS_VERSION;  
        !            45:   ret=ioctl(fd,DMSDOS_GET_DBLSB,&dblsb);
        !            46:   if(ret<0)
        !            47:   { printf("This is not a DMSDOS directory.\n");
        !            48:     exit(1);
        !            49:   }
        !            50:   printf("You are running DMSDOS Version %d.%d.%d.\n\n",(ret&0xff0000)>>16,
        !            51:          (ret&0x00ff00)>>8,ret&0xff);
        !            52:   if(ret&0x0f000000)
        !            53:   { printf("This program is too old for the DMSDOS version you are running.\n");
        !            54:     exit(1);
        !            55:   }
        !            56: 
        !            57:   dblsb structure see dmsdos.h.
        !            58: 
        !            59: DMSDOS_READ_BITFAT:
        !            60: read bitfat entry
        !            61: w[0]=sectornr; returns 0 in w[1] if sector free
        !            62: 
        !            63:   ret=ioctl(fd,DMSDOS_READ_BITFAT,w);
        !            64:   if(ret<0)error.....;
        !            65: 
        !            66: DMSDOS_WRITE_BITFAT:
        !            67: write bitfat entry
        !            68: w[0]=sectornr, w[1]=new value (0=free, 1=allocated)
        !            69: 
        !            70:   ret=ioctl(fd,DMSDOS_WRITE_BITFAT,w);
        !            71:   if(ret<0)error.....;
        !            72: 
        !            73: DMSDOS_READ_MDFAT:
        !            74: read mdfat entry
        !            75: w[0]=clusternr; returns result in mde structure.
        !            76: 
        !            77:   w[1]=&mde;
        !            78:   ret=ioctl(fd,DMSDOS_READ_MDFAT,w);
        !            79:   if(ret<0)error......;
        !            80:   
        !            81: DMSDOS_WRITE_MDFAT:
        !            82: write mdfat entry
        !            83: w[0]=clusternr; mde=new mdfat entry value.
        !            84:   
        !            85:   w[1]=&mde;
        !            86:   ret=ioctl(fd,DMSDOS_WRITE_MDFAT,w);
        !            87:   if(ret<0)error......;
        !            88: 
        !            89: raw MDFAT entry: 32/40 bit number (hidden to the user)
        !            90: 
        !            91:   dos 6.x, Win95 without drivespace 3:
        !            92:   3322222222221111111111
        !            93:   10987654321098765432109876543210 
        !            94:   ucaaaammmm?sssssssssssssssssssss
        !            95: 
        !            96:   Win95 with drivespace 3:
        !            97:   33333333322222222221111111111
        !            98:   9876543210987654321098765432109876543210 
        !            99:   ucaaaaaammmmmm??ssssssssssssssssssssssss
        !           100: 
        !           101: Mdfat_entry structure: (the dmsdos driver automatically converts it to the
        !           102:                         appropriate 32 or 40 bit number)
        !           103: 
        !           104:   mde.sector_minus_1= ('ssss...' bits)
        !           105:   mde.size_lo_minus_1= ('mmmmmm' bits)
        !           106:   mde.size_hi_minus_1= ('aaaaaa' bits)
        !           107:   mde.flags= ('uc' bits)
        !           108:   mde.unknown= ('?' bit(s)), are NOT written, always set to zero
        !           109:   
        !           110:   u: 1=entry is used, 0=entry is free
        !           111:   c: 1=cluster is uncompressed, 0=cluster is compressed
        !           112:   a: uncompressed size minus 1 (number of sectors belonging to this cluster)
        !           113:   m: compressed size minus 1 (      "      "        "          )
        !           114:   ?: unknown, but seem(s) to be used sometimes
        !           115:   s: sector number minus 1 (theoretical 2 GB limit)
        !           116:      The sector number is counted from the beginning of the CVF file
        !           117:      starting with sector number 0.
        !           118: 
        !           119: DMSDOS_SET_COMP:
        !           120: set compression method for write access.
        !           121:   
        !           122:   ioctl(fd,DMSDOS_SET_COMP,READ_ONLY); or:
        !           123:   ioctl(fd,DMSDOS_SET_COMP,UNCOMPRESSED); or:
        !           124:   ioctl(fd,DMSDOS_SET_COMP,GUESS); or:
        !           125:   ioctl(fd,DMSDOS_SET_COMP,DS_0_0); or:
        !           126:   ioctl(fd,DMSDOS_SET_COMP,DS_0_1); or:
        !           127:   ioctl(fd,DMSDOS_SET_COMP,DS_0_2); or:
        !           128:   ioctl(fd,DMSDOS_SET_COMP,JM_0_0); or:
        !           129:   ioctl(fd,DMSDOS_SET_COMP,JM_0_1); or:
        !           130:   ioctl(fd,DMSDOS_SET_COMP,SQ_0_0);
        !           131: 
        !           132: DMSDOS_SET_CF:
        !           133: set compression level:
        !           134:   
        !           135:   ioctl(fd,DMSDOS_SET_CF,level-1);
        !           136: 
        !           137: DMSDOS_EXTRA_STATFS:
        !           138: special statfs command for dmsdos
        !           139: reads special info in w.
        !           140: 
        !           141:   ioctl(fd,DMSDOS_EXTRA_STATFS,w);
        !           142: 
        !           143: w[0]= free sectors in CVF.
        !           144: w[1]= used sectors.
        !           145: w[2]= maximum free unfragmented sectors (contiguous sectors)
        !           146: w[3]= free fat clusters
        !           147: w[4]= used fat clusters
        !           148: w[5]= clusters allocated in fat but free in MDFAT (filesystem error if > 0)
        !           149: w[6]= sum of sectors used by compressed clusters
        !           150: w[7]= sum of sectors used by uncompressed clusters
        !           151: w[8]= number of compressed clusters
        !           152: w[9]= number of uncompressed clusters
        !           153: 
        !           154: DMSDOS_READ_BLOCK:
        !           155: read sector from CVF; returns sector contents in bstruct.data;
        !           156: 
        !           157:   struct bstruct
        !           158:   { unsigned long sectornr;
        !           159:     unsigned char data[512];
        !           160:   };
        !           161: 
        !           162:   bstruct.sectornr= sector number;
        !           163: 
        !           164:   ioctl(fd,DMSDOS_READ_BLOCK,&bstruct);
        !           165: 
        !           166: DMSDOS_WRITE_BLOCK:
        !           167: 
        !           168:   analogue to read_block...
        !           169: 
        !           170: DMSDOS_READ_DIRENTRY:
        !           171: DMSDOS_WRITE_DIRENTRY:
        !           172: 
        !           173:   removed and unsupported...
        !           174: 
        !           175: DMSDOS_READ_DFAT:
        !           176: w[0]=clusternr; returns fat entry value in w[1]; (last=-1 or 0xFFFFFFFF)
        !           177: 
        !           178:   ret=ioctl(fd,DMSDOS_READ_DFAT,w);
        !           179:   if(ret<0)error......;
        !           180: 
        !           181: DMSDOS_WRITE_DFAT:
        !           182: w[0]=clusternr; w[1]=new value;
        !           183: 
        !           184:   ret=ioctl(fd,DMSDOS_WRITE_DFAT,w);
        !           185:   if(ret<0)error......;
        !           186: 
        !           187: DMSDOS_SIMPLE_CHECK:
        !           188: performs simple filesystem check (crosslinks & allocation errors)
        !           189: w[0]=0; means do not try to repair errors
        !           190: 
        !           191: returns result in w[0] (0=ok, -1=FAT error, -2=MDFAT error, -3=BITFAT error,
        !           192:                         1=out of memory, check aborted,
        !           193:                         2=FAT ok, but out of memory for MDFAT check)
        !           194: 
        !           195:   ioctl(fd,DMSDOS_SIMPLE_CHECK,w);
        !           196:   if(w[0]==....)printf(.....);
        !           197: 
        !           198: 
        !           199: dmsdos daemon ioctls missing here....

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