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1.1 root 1: DMSDOS ioctl commands (outdated....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4: WARNING: INFORMATION IN THIS FILE IS OUTDATED AND PARTIALLY WRONG.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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