block/partitions/aix.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  fs/partitions/aix.c
   4  *
   5  *  Copyright (C) 2012-2013 Philippe De Muyter <phdm@macqel.be>
   6  */
   7
   8 #include "check.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  * read_lba(): Read bytes from disk, starting at given LBA
  71  * @state
  72  * @lba
  73  * @buffer
  74  * @count
  75  *
  76  * Description:  Reads @count bytes from @state->disk into @buffer.
  77  * Returns number of bytes read on success, 0 on error.
  78  */
  79 static size_t read_lba(struct parsed_partitions *state, u64 lba, u8 *buffer,
  80                         size_t count)
  81 {
  82         size_t totalreadcount = 0;
  83
  84         if (!buffer || lba + count / 512 > get_capacity(state->disk) - 1ULL)
  85                 return 0;
  86
  87         while (count) {
  88                 int copied = 512;
  89                 Sector sect;
  90                 unsigned char *data = read_part_sector(state, lba++, &sect);
  91                 if (!data)
  92                         break;
  93                 if (copied > count)
  94                         copied = count;
  95                 memcpy(buffer, data, copied);
  96                 put_dev_sector(sect);
  97                 buffer += copied;
  98                 totalreadcount += copied;
  99                 count -= copied;
 100         }
 101         return totalreadcount;
 102 }
 103
 104 /**
 105  * alloc_pvd(): reads physical volume descriptor
 106  * @state
 107  * @lba
 108  *
 109  * Description: Returns pvd on success,  NULL on error.
 110  * Allocates space for pvd and fill it with disk blocks at @lba
 111  * Notes: remember to free pvd when you're done!
 112  */
 113 static struct pvd *alloc_pvd(struct parsed_partitions *state, u32 lba)
 114 {
 115         size_t count = sizeof(struct pvd);
 116         struct pvd *p;
 117
 118         p = kmalloc(count, GFP_KERNEL);
 119         if (!p)
 120                 return NULL;
 121
 122         if (read_lba(state, lba, (u8 *) p, count) < count) {
 123                 kfree(p);
 124                 return NULL;
 125         }
 126         return p;
 127 }
 128
 129 /**
 130  * alloc_lvn(): reads logical volume names
 131  * @state
 132  * @lba
 133  *
 134  * Description: Returns lvn on success,  NULL on error.
 135  * Allocates space for lvn and fill it with disk blocks at @lba
 136  * Notes: remember to free lvn when you're done!
 137  */
 138 static struct lvname *alloc_lvn(struct parsed_partitions *state, u32 lba)
 139 {
 140         size_t count = sizeof(struct lvname) * LVM_MAXLVS;
 141         struct lvname *p;
 142
 143         p = kmalloc(count, GFP_KERNEL);
 144         if (!p)
 145                 return NULL;
 146
 147         if (read_lba(state, lba, (u8 *) p, count) < count) {
 148                 kfree(p);
 149                 return NULL;
 150         }
 151         return p;
 152 }
 153
 154 int aix_partition(struct parsed_partitions *state)
 155 {
 156         int ret = 0;
 157         Sector sect;
 158         unsigned char *d;
 159         u32 pp_bytes_size;
 160         u32 pp_blocks_size = 0;
 161         u32 vgda_sector = 0;
 162         u32 vgda_len = 0;
 163         int numlvs = 0;
 164         struct pvd *pvd = NULL;
 165         struct lv_info {
 166                 unsigned short pps_per_lv;
 167                 unsigned short pps_found;
 168                 unsigned char lv_is_contiguous;
 169         } *lvip;
 170         struct lvname *n = NULL;
 171
 172         d = read_part_sector(state, 7, &sect);
 173         if (d) {
 174                 struct lvm_rec *p = (struct lvm_rec *)d;
 175                 u16 lvm_version = be16_to_cpu(p->version);
 176                 char tmp[64];
 177
 178                 if (lvm_version == 1) {
 179                         int pp_size_log2 = be16_to_cpu(p->pp_size);
 180
 181                         pp_bytes_size = 1 << pp_size_log2;
 182                         pp_blocks_size = pp_bytes_size / 512;
 183                         snprintf(tmp, sizeof(tmp),
 184                                 " AIX LVM header version %u found\n",
 185                                 lvm_version);
 186                         vgda_len = be32_to_cpu(p->vgda_len);
 187                         vgda_sector = be32_to_cpu(p->vgda_psn[0]);
 188                 } else {
 189                         snprintf(tmp, sizeof(tmp),
 190                                 " unsupported AIX LVM version %d found\n",
 191                                 lvm_version);
 192                 }
 193                 strlcat(state->pp_buf, tmp, PAGE_SIZE);
 194                 put_dev_sector(sect);
 195         }
 196         if (vgda_sector && (d = read_part_sector(state, vgda_sector, &sect))) {
 197                 struct vgda *p = (struct vgda *)d;
 198
 199                 numlvs = be16_to_cpu(p->numlvs);
 200                 put_dev_sector(sect);
 201         }
 202         lvip = kcalloc(state->limit, sizeof(struct lv_info), GFP_KERNEL);
 203         if (!lvip)
 204                 return 0;
 205         if (numlvs && (d = read_part_sector(state, vgda_sector + 1, &sect))) {
 206                 struct lvd *p = (struct lvd *)d;
 207                 int i;
 208
 209                 n = alloc_lvn(state, vgda_sector + vgda_len - 33);
 210                 if (n) {
 211                         int foundlvs = 0;
 212
 213                         for (i = 0; foundlvs < numlvs && i < state->limit; i += 1) {
 214                                 lvip[i].pps_per_lv = be16_to_cpu(p[i].num_lps);
 215                                 if (lvip[i].pps_per_lv)
 216                                         foundlvs += 1;
 217                         }
 218                         /* pvd loops depend on n[].name and lvip[].pps_per_lv */
 219                         pvd = alloc_pvd(state, vgda_sector + 17);
 220                 }
 221                 put_dev_sector(sect);
 222         }
 223         if (pvd) {
 224                 int numpps = be16_to_cpu(pvd->pp_count);
 225                 int psn_part1 = be32_to_cpu(pvd->psn_part1);
 226                 int i;
 227                 int cur_lv_ix = -1;
 228                 int next_lp_ix = 1;
 229                 int lp_ix;
 230
 231                 for (i = 0; i < numpps; i += 1) {
 232                         struct ppe *p = pvd->ppe + i;
 233                         unsigned int lv_ix;
 234
 235                         lp_ix = be16_to_cpu(p->lp_ix);
 236                         if (!lp_ix) {
 237                                 next_lp_ix = 1;
 238                                 continue;
 239                         }
 240                         lv_ix = be16_to_cpu(p->lv_ix) - 1;
 241                         if (lv_ix >= state->limit) {
 242                                 cur_lv_ix = -1;
 243                                 continue;
 244                         }
 245                         lvip[lv_ix].pps_found += 1;
 246                         if (lp_ix == 1) {
 247                                 cur_lv_ix = lv_ix;
 248                                 next_lp_ix = 1;
 249                         } else if (lv_ix != cur_lv_ix || lp_ix != next_lp_ix) {
 250                                 next_lp_ix = 1;
 251                                 continue;
 252                         }
 253                         if (lp_ix == lvip[lv_ix].pps_per_lv) {
 254                                 char tmp[70];
 255
 256                                 put_partition(state, lv_ix + 1,
 257                                   (i + 1 - lp_ix) * pp_blocks_size + psn_part1,
 258                                   lvip[lv_ix].pps_per_lv * pp_blocks_size);
 259                                 snprintf(tmp, sizeof(tmp), " <%s>\n",
 260                                          n[lv_ix].name);
 261                                 strlcat(state->pp_buf, tmp, PAGE_SIZE);
 262                                 lvip[lv_ix].lv_is_contiguous = 1;
 263                                 ret = 1;
 264                                 next_lp_ix = 1;
 265                         } else
 266                                 next_lp_ix += 1;
 267                 }
 268                 for (i = 0; i < state->limit; i += 1)
 269                         if (lvip[i].pps_found && !lvip[i].lv_is_contiguous) {
 270                                 char tmp[sizeof(n[i].name) + 1]; // null char
 271
 272                                 snprintf(tmp, sizeof(tmp), "%s", n[i].name);
 273                                 pr_warn("partition %s (%u pp's found) is "
 274                                         "not contiguous\n",
 275                                         tmp, lvip[i].pps_found);
 276                         }
 277                 kfree(pvd);
 278         }
 279         kfree(n);
 280         kfree(lvip);
 281         return ret;
 282 }