block/cmdline-parser.c

   1 /*
   2  * Parse command line, get partition information
   3  *
   4  * Written by Cai Zhiyong <caizhiyong@huawei.com>
   5  *
   6  */
   7 #include <linux/export.h>
   8 #include <linux/cmdline-parser.h>
   9
  10 static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
  11 {
  12         int ret = 0;
  13         struct cmdline_subpart *new_subpart;
  14
  15         *subpart = NULL;
  16
  17         new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
  18         if (!new_subpart)
  19                 return -ENOMEM;
  20
  21         if (*partdef == '-') {
  22                 new_subpart->size = (sector_t)(~0ULL);
  23                 partdef++;
  24         } else {
  25                 new_subpart->size = (sector_t)memparse(partdef, &partdef);
  26                 if (new_subpart->size < (sector_t)PAGE_SIZE) {
  27                         pr_warn("cmdline partition size is invalid.");
  28                         ret = -EINVAL;
  29                         goto fail;
  30                 }
  31         }
  32
  33         if (*partdef == '@') {
  34                 partdef++;
  35                 new_subpart->from = (sector_t)memparse(partdef, &partdef);
  36         } else {
  37                 new_subpart->from = (sector_t)(~0ULL);
  38         }
  39
  40         if (*partdef == '(') {
  41                 int length;
  42                 char *next = strchr(++partdef, ')');
  43
  44                 if (!next) {
  45                         pr_warn("cmdline partition format is invalid.");
  46                         ret = -EINVAL;
  47                         goto fail;
  48                 }
  49
  50                 length = min_t(int, next - partdef,
  51                                sizeof(new_subpart->name) - 1);
  52                 strncpy(new_subpart->name, partdef, length);
  53                 new_subpart->name[length] = '\0';
  54
  55                 partdef = ++next;
  56         } else
  57                 new_subpart->name[0] = '\0';
  58
  59         new_subpart->flags = 0;
  60
  61         if (!strncmp(partdef, "ro", 2)) {
  62                 new_subpart->flags |= PF_RDONLY;
  63                 partdef += 2;
  64         }
  65
  66         if (!strncmp(partdef, "lk", 2)) {
  67                 new_subpart->flags |= PF_POWERUP_LOCK;
  68                 partdef += 2;
  69         }
  70
  71         *subpart = new_subpart;
  72         return 0;
  73 fail:
  74         kfree(new_subpart);
  75         return ret;
  76 }
  77
  78 static void free_subpart(struct cmdline_parts *parts)
  79 {
  80         struct cmdline_subpart *subpart;
  81
  82         while (parts->subpart) {
  83                 subpart = parts->subpart;
  84                 parts->subpart = subpart->next_subpart;
  85                 kfree(subpart);
  86         }
  87 }
  88
  89 static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
  90 {
  91         int ret = -EINVAL;
  92         char *next;
  93         int length;
  94         struct cmdline_subpart **next_subpart;
  95         struct cmdline_parts *newparts;
  96         char buf[BDEVNAME_SIZE + 32 + 4];
  97
  98         *parts = NULL;
  99
 100         newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
 101         if (!newparts)
 102                 return -ENOMEM;
 103
 104         next = strchr(bdevdef, ':');
 105         if (!next) {
 106                 pr_warn("cmdline partition has no block device.");
 107                 goto fail;
 108         }
 109
 110         length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1);
 111         strncpy(newparts->name, bdevdef, length);
 112         newparts->name[length] = '\0';
 113         newparts->nr_subparts = 0;
 114
 115         next_subpart = &newparts->subpart;
 116
 117         while (next && *(++next)) {
 118                 bdevdef = next;
 119                 next = strchr(bdevdef, ',');
 120
 121                 length = (!next) ? (sizeof(buf) - 1) :
 122                         min_t(int, next - bdevdef, sizeof(buf) - 1);
 123
 124                 strncpy(buf, bdevdef, length);
 125                 buf[length] = '\0';
 126
 127                 ret = parse_subpart(next_subpart, buf);
 128                 if (ret)
 129                         goto fail;
 130
 131                 newparts->nr_subparts++;
 132                 next_subpart = &(*next_subpart)->next_subpart;
 133         }
 134
 135         if (!newparts->subpart) {
 136                 pr_warn("cmdline partition has no valid partition.");
 137                 ret = -EINVAL;
 138                 goto fail;
 139         }
 140
 141         *parts = newparts;
 142
 143         return 0;
 144 fail:
 145         free_subpart(newparts);
 146         kfree(newparts);
 147         return ret;
 148 }
 149
 150 void cmdline_parts_free(struct cmdline_parts **parts)
 151 {
 152         struct cmdline_parts *next_parts;
 153
 154         while (*parts) {
 155                 next_parts = (*parts)->next_parts;
 156                 free_subpart(*parts);
 157                 kfree(*parts);
 158                 *parts = next_parts;
 159         }
 160 }
 161 EXPORT_SYMBOL(cmdline_parts_free);
 162
 163 int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline)
 164 {
 165         int ret;
 166         char *buf;
 167         char *pbuf;
 168         char *next;
 169         struct cmdline_parts **next_parts;
 170
 171         *parts = NULL;
 172
 173         next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
 174         if (!buf)
 175                 return -ENOMEM;
 176
 177         next_parts = parts;
 178
 179         while (next && *pbuf) {
 180                 next = strchr(pbuf, ';');
 181                 if (next)
 182                         *next = '\0';
 183
 184                 ret = parse_parts(next_parts, pbuf);
 185                 if (ret)
 186                         goto fail;
 187
 188                 if (next)
 189                         pbuf = ++next;
 190
 191                 next_parts = &(*next_parts)->next_parts;
 192         }
 193
 194         if (!*parts) {
 195                 pr_warn("cmdline partition has no valid partition.");
 196                 ret = -EINVAL;
 197                 goto fail;
 198         }
 199
 200         ret = 0;
 201 done:
 202         kfree(buf);
 203         return ret;
 204
 205 fail:
 206         cmdline_parts_free(parts);
 207         goto done;
 208 }
 209 EXPORT_SYMBOL(cmdline_parts_parse);
 210
 211 struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
 212                                          const char *bdev)
 213 {
 214         while (parts && strncmp(bdev, parts->name, sizeof(parts->name)))
 215                 parts = parts->next_parts;
 216         return parts;
 217 }
 218 EXPORT_SYMBOL(cmdline_parts_find);
 219
 220 /*
 221  *  add_part()
 222  *    0 success.
 223  *    1 can not add so many partitions.
 224  */
 225 int cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
 226                       int slot,
 227                       int (*add_part)(int, struct cmdline_subpart *, void *),
 228                       void *param)
 229 {
 230         sector_t from = 0;
 231         struct cmdline_subpart *subpart;
 232
 233         for (subpart = parts->subpart; subpart;
 234              subpart = subpart->next_subpart, slot++) {
 235                 if (subpart->from == (sector_t)(~0ULL))
 236                         subpart->from = from;
 237                 else
 238                         from = subpart->from;
 239
 240                 if (from >= disk_size)
 241                         break;
 242
 243                 if (subpart->size > (disk_size - from))
 244                         subpart->size = disk_size - from;
 245
 246                 from += subpart->size;
 247
 248                 if (add_part(slot, subpart, param))
 249                         break;
 250         }
 251
 252         return slot;
 253 }
 254 EXPORT_SYMBOL(cmdline_parts_set);