namei.c: remove utterly outdated comment
[linux-2.6] / fs / partitions / ibm.c
1 /*
2  * File...........: linux/fs/partitions/ibm.c
3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4  *                  Volker Sameske <sameske@de.ibm.com>
5  * Bugreports.to..: <Linux390@de.ibm.com>
6  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
7  */
8
9 #include <linux/buffer_head.h>
10 #include <linux/hdreg.h>
11 #include <linux/slab.h>
12 #include <asm/dasd.h>
13 #include <asm/ebcdic.h>
14 #include <asm/uaccess.h>
15 #include <asm/vtoc.h>
16
17 #include "check.h"
18 #include "ibm.h"
19
20 /*
21  * compute the block number from a
22  * cyl-cyl-head-head structure
23  */
24 static inline int
25 cchh2blk (struct vtoc_cchh *ptr, struct hd_geometry *geo) {
26         return ptr->cc * geo->heads * geo->sectors +
27                ptr->hh * geo->sectors;
28 }
29
30 /*
31  * compute the block number from a
32  * cyl-cyl-head-head-block structure
33  */
34 static inline int
35 cchhb2blk (struct vtoc_cchhb *ptr, struct hd_geometry *geo) {
36         return ptr->cc * geo->heads * geo->sectors +
37                 ptr->hh * geo->sectors +
38                 ptr->b;
39 }
40
41 /*
42  */
43 int
44 ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
45 {
46         int blocksize, offset, size,res;
47         loff_t i_size;
48         dasd_information_t *info;
49         struct hd_geometry *geo;
50         char type[5] = {0,};
51         char name[7] = {0,};
52         union label_t {
53                 struct vtoc_volume_label vol;
54                 struct vtoc_cms_label cms;
55         } *label;
56         unsigned char *data;
57         Sector sect;
58
59         res = 0;
60         blocksize = bdev_hardsect_size(bdev);
61         if (blocksize <= 0)
62                 goto out_exit;
63         i_size = i_size_read(bdev->bd_inode);
64         if (i_size == 0)
65                 goto out_exit;
66
67         if ((info = kmalloc(sizeof(dasd_information_t), GFP_KERNEL)) == NULL)
68                 goto out_exit;
69         if ((geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL)) == NULL)
70                 goto out_nogeo;
71         if ((label = kmalloc(sizeof(union label_t), GFP_KERNEL)) == NULL)
72                 goto out_nolab;
73
74         if (ioctl_by_bdev(bdev, BIODASDINFO, (unsigned long)info) != 0 ||
75             ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)geo) != 0)
76                 goto out_freeall;
77
78         /*
79          * Get volume label, extract name and type.
80          */
81         data = read_dev_sector(bdev, info->label_block*(blocksize/512), &sect);
82         if (data == NULL)
83                 goto out_readerr;
84
85         strncpy (type, data, 4);
86         if ((!info->FBA_layout) && (!strcmp(info->type, "ECKD")))
87                 strncpy(name, data + 8, 6);
88         else
89                 strncpy(name, data + 4, 6);
90         memcpy(label, data, sizeof(union label_t));
91         put_dev_sector(sect);
92
93         EBCASC(type, 4);
94         EBCASC(name, 6);
95
96         res = 1;
97
98         /*
99          * Three different types: CMS1, VOL1 and LNX1/unlabeled
100          */
101         if (strncmp(type, "CMS1", 4) == 0) {
102                 /*
103                  * VM style CMS1 labeled disk
104                  */
105                 if (label->cms.disk_offset != 0) {
106                         printk("CMS1/%8s(MDSK):", name);
107                         /* disk is reserved minidisk */
108                         blocksize = label->cms.block_size;
109                         offset = label->cms.disk_offset;
110                         size = (label->cms.block_count - 1) * (blocksize >> 9);
111                 } else {
112                         printk("CMS1/%8s:", name);
113                         offset = (info->label_block + 1);
114                         size = i_size >> 9;
115                 }
116                 put_partition(state, 1, offset*(blocksize >> 9),
117                                  size-offset*(blocksize >> 9));
118         } else if ((strncmp(type, "VOL1", 4) == 0) &&
119                 (!info->FBA_layout) && (!strcmp(info->type, "ECKD"))) {
120                 /*
121                  * New style VOL1 labeled disk
122                  */
123                 unsigned int blk;
124                 int counter;
125
126                 printk("VOL1/%8s:", name);
127
128                 /* get block number and read then go through format1 labels */
129                 blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
130                 counter = 0;
131                 while ((data = read_dev_sector(bdev, blk*(blocksize/512),
132                                                &sect)) != NULL) {
133                         struct vtoc_format1_label f1;
134
135                         memcpy(&f1, data, sizeof(struct vtoc_format1_label));
136                         put_dev_sector(sect);
137
138                         /* skip FMT4 / FMT5 / FMT7 labels */
139                         if (f1.DS1FMTID == _ascebc['4']
140                             || f1.DS1FMTID == _ascebc['5']
141                             || f1.DS1FMTID == _ascebc['7']) {
142                                 blk++;
143                                 continue;
144                         }
145
146                         /* only FMT1 valid at this point */
147                         if (f1.DS1FMTID != _ascebc['1'])
148                                 break;
149
150                         /* OK, we got valid partition data */
151                         offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
152                         size  = cchh2blk(&f1.DS1EXT1.ulimit, geo) -
153                                 offset + geo->sectors;
154                         if (counter >= state->limit)
155                                 break;
156                         put_partition(state, counter + 1,
157                                       offset * (blocksize >> 9),
158                                       size * (blocksize >> 9));
159                         counter++;
160                         blk++;
161                 }
162                 if (!data)
163                 /* Are we not supposed to report this ? */
164                         goto out_readerr;
165         } else {
166                 /*
167                  * Old style LNX1 or unlabeled disk
168                  */
169                 if (strncmp(type, "LNX1", 4) == 0)
170                         printk ("LNX1/%8s:", name);
171                 else
172                         printk("(nonl)/%8s:", name);
173                 offset = (info->label_block + 1);
174                 size = i_size >> 9;
175                 put_partition(state, 1, offset*(blocksize >> 9),
176                               size-offset*(blocksize >> 9));
177         }
178
179         printk("\n");
180         goto out_freeall;
181
182
183 out_readerr:
184         res = -1;
185 out_freeall:
186         kfree(label);
187 out_nolab:
188         kfree(geo);
189 out_nogeo:
190         kfree(info);
191 out_exit:
192         return res;
193 }