block/partitions/aix.c

   1 /*
   2  *  fs/partitions/aix.c
   3  *
   4  *  Copyright (C) 2012-2013 Philippe De Muyter <phdm@macqel.be>
   5  */
   6
   7 #include "check.h"
   8 #include "aix.h"
   9
  10 struct lvm_rec {
  11         char lvm_id[4]; /* "_LVM" */
  12         char reserved4[16];
  13         __be32 lvmarea_len;
  14         __be32 vgda_len;
  15         __be32 vgda_psn[2];
  16         char reserved36[10];
  17         __be16 pp_size; /* log2(pp_size) */
  18         char reserved46[12];
  19         __be16 version;
  20         };
  21
  22 struct vgda {
  23         __be32 secs;
  24         __be32 usec;
  25         char reserved8[16];
  26         __be16 numlvs;
  27         __be16 maxlvs;
  28         __be16 pp_size;
  29         __be16 numpvs;
  30         __be16 total_vgdas;
  31         __be16 vgda_size;
  32         };
  33
  34 struct lvd {
  35         __be16 lv_ix;
  36         __be16 res2;
  37         __be16 res4;
  38         __be16 maxsize;
  39         __be16 lv_state;
  40         __be16 mirror;
  41         __be16 mirror_policy;
  42         __be16 num_lps;
  43         __be16 res10[8];
  44         };
  45
  46 struct lvname {
  47         char name[64];
  48         };
  49
  50 struct ppe {
  51         __be16 lv_ix;
  52         unsigned short res2;
  53         unsigned short res4;
  54         __be16 lp_ix;
  55         unsigned short res8[12];
  56         };
  57
  58 struct pvd {
  59         char reserved0[16];
  60         __be16 pp_count;
  61         char reserved18[2];
  62         __be32 psn_part1;
  63         char reserved24[8];
  64         struct ppe ppe[1016];
  65         };
  66
  67 #define LVM_MAXLVS 256
  68
  69 /**
  70  * last_lba(): return number of last logical block of device
  71  * @bdev: block device
  72  *
  73  * Description: Returns last LBA value on success, 0 on error.
  74  * This is stored (by sd and ide-geometry) in
  75  *  the part[0] entry for this disk, and is the number of
  76  *  physical sectors available on the disk.
  77  */
  78 static u64 last_lba(struct block_device *bdev)
  79 {
  80         if (!bdev || !bdev->bd_inode)
  81                 return 0;
  82         return (bdev->bd_inode->i_size >> 9) - 1ULL;
  83 }
  84
  85 /**
  86  * read_lba(): Read bytes from disk, starting at given LBA
  87  * @state
  88  * @lba
  89  * @buffer
  90  * @count
  91  *
  92  * Description:  Reads @count bytes from @state->bdev into @buffer.
  93  * Returns number of bytes read on success, 0 on error.
  94  */
  95 static size_t read_lba(struct parsed_partitions *state, u64 lba, u8 *buffer,
  96                         size_t count)
  97 {
  98         size_t totalreadcount = 0;
  99
 100         if (!buffer || lba + count / 512 > last_lba(state->bdev))
 101                 return 0;
 102
 103         while (count) {
 104                 int copied = 512;
 105                 Sector sect;
 106                 unsigned char *data = read_part_sector(state, lba++, &sect);
 107                 if (!data)
 108                         break;
 109                 if (copied > count)
 110                         copied = count;
 111                 memcpy(buffer, data, copied);
 112                 put_dev_sector(sect);
 113                 buffer += copied;
 114                 totalreadcount += copied;
 115                 count -= copied;
 116         }
 117         return totalreadcount;
 118 }
 119
 120 /**
 121  * alloc_pvd(): reads physical volume descriptor
 122  * @state
 123  * @lba
 124  *
 125  * Description: Returns pvd on success,  NULL on error.
 126  * Allocates space for pvd and fill it with disk blocks at @lba
 127  * Notes: remember to free pvd when you're done!
 128  */
 129 static struct pvd *alloc_pvd(struct parsed_partitions *state, u32 lba)
 130 {
 131         size_t count = sizeof(struct pvd);
 132         struct pvd *p;
 133
 134         p = kmalloc(count, GFP_KERNEL);
 135         if (!p)
 136                 return NULL;
 137
 138         if (read_lba(state, lba, (u8 *) p, count) < count) {
 139                 kfree(p);
 140                 return NULL;
 141         }
 142         return p;
 143 }
 144
 145 /**
 146  * alloc_lvn(): reads logical volume names
 147  * @state
 148  * @lba
 149  *
 150  * Description: Returns lvn on success,  NULL on error.
 151  * Allocates space for lvn and fill it with disk blocks at @lba
 152  * Notes: remember to free lvn when you're done!
 153  */
 154 static struct lvname *alloc_lvn(struct parsed_partitions *state, u32 lba)
 155 {
 156         size_t count = sizeof(struct lvname) * LVM_MAXLVS;
 157         struct lvname *p;
 158
 159         p = kmalloc(count, GFP_KERNEL);
 160         if (!p)
 161                 return NULL;
 162
 163         if (read_lba(state, lba, (u8 *) p, count) < count) {
 164                 kfree(p);
 165                 return NULL;
 166         }
 167         return p;
 168 }
 169
 170 int aix_partition(struct parsed_partitions *state)
 171 {
 172         int ret = 0;
 173         Sector sect;
 174         unsigned char *d;
 175         u32 pp_bytes_size;
 176         u32 pp_blocks_size = 0;
 177         u32 vgda_sector = 0;
 178         u32 vgda_len = 0;
 179         int numlvs = 0;
 180         struct pvd *pvd;
 181         struct lv_info {
 182                 unsigned short pps_per_lv;
 183                 unsigned short pps_found;
 184                 unsigned char lv_is_contiguous;
 185         } *lvip;
 186         struct lvname *n = NULL;
 187
 188         d = read_part_sector(state, 7, &sect);
 189         if (d) {
 190                 struct lvm_rec *p = (struct lvm_rec *)d;
 191                 u16 lvm_version = be16_to_cpu(p->version);
 192                 char tmp[64];
 193
 194                 if (lvm_version == 1) {
 195                         int pp_size_log2 = be16_to_cpu(p->pp_size);
 196
 197                         pp_bytes_size = 1 << pp_size_log2;
 198                         pp_blocks_size = pp_bytes_size / 512;
 199                         snprintf(tmp, sizeof(tmp),
 200                                 " AIX LVM header version %u found\n",
 201                                 lvm_version);
 202                         vgda_len = be32_to_cpu(p->vgda_len);
 203                         vgda_sector = be32_to_cpu(p->vgda_psn[0]);
 204                 } else {
 205                         snprintf(tmp, sizeof(tmp),
 206                                 " unsupported AIX LVM version %d found\n",
 207                                 lvm_version);
 208                 }
 209                 strlcat(state->pp_buf, tmp, PAGE_SIZE);
 210                 put_dev_sector(sect);
 211         }
 212         if (vgda_sector && (d = read_part_sector(state, vgda_sector, &sect))) {
 213                 struct vgda *p = (struct vgda *)d;
 214
 215                 numlvs = be16_to_cpu(p->numlvs);
 216                 put_dev_sector(sect);
 217         }
 218         lvip = kcalloc(state->limit, sizeof(struct lv_info), GFP_KERNEL);
 219         if (!lvip)
 220                 return 0;
 221         if (numlvs && (d = read_part_sector(state, vgda_sector + 1, &sect))) {
 222                 struct lvd *p = (struct lvd *)d;
 223                 int i;
 224
 225                 n = alloc_lvn(state, vgda_sector + vgda_len - 33);
 226                 if (n) {
 227                         int foundlvs = 0;
 228
 229                         for (i = 0; foundlvs < numlvs && i < state->limit; i += 1) {
 230                                 lvip[i].pps_per_lv = be16_to_cpu(p[i].num_lps);
 231                                 if (lvip[i].pps_per_lv)
 232                                         foundlvs += 1;
 233                         }
 234                 }
 235                 put_dev_sector(sect);
 236         }
 237         pvd = alloc_pvd(state, vgda_sector + 17);
 238         if (pvd) {
 239                 int numpps = be16_to_cpu(pvd->pp_count);
 240                 int psn_part1 = be32_to_cpu(pvd->psn_part1);
 241                 int i;
 242                 int cur_lv_ix = -1;
 243                 int next_lp_ix = 1;
 244                 int lp_ix;
 245
 246                 for (i = 0; i < numpps; i += 1) {
 247                         struct ppe *p = pvd->ppe + i;
 248                         unsigned int lv_ix;
 249
 250                         lp_ix = be16_to_cpu(p->lp_ix);
 251                         if (!lp_ix) {
 252                                 next_lp_ix = 1;
 253                                 continue;
 254                         }
 255                         lv_ix = be16_to_cpu(p->lv_ix) - 1;
 256                         if (lv_ix >= state->limit) {
 257                                 cur_lv_ix = -1;
 258                                 continue;
 259                         }
 260                         lvip[lv_ix].pps_found += 1;
 261                         if (lp_ix == 1) {
 262                                 cur_lv_ix = lv_ix;
 263                                 next_lp_ix = 1;
 264                         } else if (lv_ix != cur_lv_ix || lp_ix != next_lp_ix) {
 265                                 next_lp_ix = 1;
 266                                 continue;
 267                         }
 268                         if (lp_ix == lvip[lv_ix].pps_per_lv) {
 269                                 char tmp[70];
 270
 271                                 put_partition(state, lv_ix + 1,
 272                                   (i + 1 - lp_ix) * pp_blocks_size + psn_part1,
 273                                   lvip[lv_ix].pps_per_lv * pp_blocks_size);
 274                                 snprintf(tmp, sizeof(tmp), " <%s>\n",
 275                                          n[lv_ix].name);
 276                                 strlcat(state->pp_buf, tmp, PAGE_SIZE);
 277                                 lvip[lv_ix].lv_is_contiguous = 1;
 278                                 ret = 1;
 279                                 next_lp_ix = 1;
 280                         } else
 281                                 next_lp_ix += 1;
 282                 }
 283                 for (i = 0; i < state->limit; i += 1)
 284                         if (lvip[i].pps_found && !lvip[i].lv_is_contiguous)
 285                                 pr_warn("partition %s (%u pp's found) is "
 286                                         "not contiguous\n",
 287                                         n[i].name, lvip[i].pps_found);
 288                 kfree(pvd);
 289         }
 290         kfree(n);
 291         kfree(lvip);
 292         return ret;
 293 }