net/ceph/cls_lock_client.c

   1 #include <linux/ceph/ceph_debug.h>
   2
   3 #include <linux/types.h>
   4 #include <linux/slab.h>
   5
   6 #include <linux/ceph/cls_lock_client.h>
   7 #include <linux/ceph/decode.h>
   8
   9 /**
  10  * ceph_cls_lock - grab rados lock for object
  11  * @oid, @oloc: object to lock
  12  * @lock_name: the name of the lock
  13  * @type: lock type (CEPH_CLS_LOCK_EXCLUSIVE or CEPH_CLS_LOCK_SHARED)
  14  * @cookie: user-defined identifier for this instance of the lock
  15  * @tag: user-defined tag
  16  * @desc: user-defined lock description
  17  * @flags: lock flags
  18  *
  19  * All operations on the same lock should use the same tag.
  20  */
  21 int ceph_cls_lock(struct ceph_osd_client *osdc,
  22                   struct ceph_object_id *oid,
  23                   struct ceph_object_locator *oloc,
  24                   char *lock_name, u8 type, char *cookie,
  25                   char *tag, char *desc, u8 flags)
  26 {
  27         int lock_op_buf_size;
  28         int name_len = strlen(lock_name);
  29         int cookie_len = strlen(cookie);
  30         int tag_len = strlen(tag);
  31         int desc_len = strlen(desc);
  32         void *p, *end;
  33         struct page *lock_op_page;
  34         struct timespec mtime;
  35         int ret;
  36
  37         lock_op_buf_size = name_len + sizeof(__le32) +
  38                            cookie_len + sizeof(__le32) +
  39                            tag_len + sizeof(__le32) +
  40                            desc_len + sizeof(__le32) +
  41                            sizeof(struct ceph_timespec) +
  42                            /* flag and type */
  43                            sizeof(u8) + sizeof(u8) +
  44                            CEPH_ENCODING_START_BLK_LEN;
  45         if (lock_op_buf_size > PAGE_SIZE)
  46                 return -E2BIG;
  47
  48         lock_op_page = alloc_page(GFP_NOIO);
  49         if (!lock_op_page)
  50                 return -ENOMEM;
  51
  52         p = page_address(lock_op_page);
  53         end = p + lock_op_buf_size;
  54
  55         /* encode cls_lock_lock_op struct */
  56         ceph_start_encoding(&p, 1, 1,
  57                             lock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
  58         ceph_encode_string(&p, end, lock_name, name_len);
  59         ceph_encode_8(&p, type);
  60         ceph_encode_string(&p, end, cookie, cookie_len);
  61         ceph_encode_string(&p, end, tag, tag_len);
  62         ceph_encode_string(&p, end, desc, desc_len);
  63         /* only support infinite duration */
  64         memset(&mtime, 0, sizeof(mtime));
  65         ceph_encode_timespec(p, &mtime);
  66         p += sizeof(struct ceph_timespec);
  67         ceph_encode_8(&p, flags);
  68
  69         dout("%s lock_name %s type %d cookie %s tag %s desc %s flags 0x%x\n",
  70              __func__, lock_name, type, cookie, tag, desc, flags);
  71         ret = ceph_osdc_call(osdc, oid, oloc, "lock", "lock",
  72                              CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
  73                              lock_op_page, lock_op_buf_size, NULL, NULL);
  74
  75         dout("%s: status %d\n", __func__, ret);
  76         __free_page(lock_op_page);
  77         return ret;
  78 }
  79 EXPORT_SYMBOL(ceph_cls_lock);
  80
  81 /**
  82  * ceph_cls_unlock - release rados lock for object
  83  * @oid, @oloc: object to lock
  84  * @lock_name: the name of the lock
  85  * @cookie: user-defined identifier for this instance of the lock
  86  */
  87 int ceph_cls_unlock(struct ceph_osd_client *osdc,
  88                     struct ceph_object_id *oid,
  89                     struct ceph_object_locator *oloc,
  90                     char *lock_name, char *cookie)
  91 {
  92         int unlock_op_buf_size;
  93         int name_len = strlen(lock_name);
  94         int cookie_len = strlen(cookie);
  95         void *p, *end;
  96         struct page *unlock_op_page;
  97         int ret;
  98
  99         unlock_op_buf_size = name_len + sizeof(__le32) +
 100                              cookie_len + sizeof(__le32) +
 101                              CEPH_ENCODING_START_BLK_LEN;
 102         if (unlock_op_buf_size > PAGE_SIZE)
 103                 return -E2BIG;
 104
 105         unlock_op_page = alloc_page(GFP_NOIO);
 106         if (!unlock_op_page)
 107                 return -ENOMEM;
 108
 109         p = page_address(unlock_op_page);
 110         end = p + unlock_op_buf_size;
 111
 112         /* encode cls_lock_unlock_op struct */
 113         ceph_start_encoding(&p, 1, 1,
 114                             unlock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
 115         ceph_encode_string(&p, end, lock_name, name_len);
 116         ceph_encode_string(&p, end, cookie, cookie_len);
 117
 118         dout("%s lock_name %s cookie %s\n", __func__, lock_name, cookie);
 119         ret = ceph_osdc_call(osdc, oid, oloc, "lock", "unlock",
 120                              CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
 121                              unlock_op_page, unlock_op_buf_size, NULL, NULL);
 122
 123         dout("%s: status %d\n", __func__, ret);
 124         __free_page(unlock_op_page);
 125         return ret;
 126 }
 127 EXPORT_SYMBOL(ceph_cls_unlock);
 128
 129 /**
 130  * ceph_cls_break_lock - release rados lock for object for specified client
 131  * @oid, @oloc: object to lock
 132  * @lock_name: the name of the lock
 133  * @cookie: user-defined identifier for this instance of the lock
 134  * @locker: current lock owner
 135  */
 136 int ceph_cls_break_lock(struct ceph_osd_client *osdc,
 137                         struct ceph_object_id *oid,
 138                         struct ceph_object_locator *oloc,
 139                         char *lock_name, char *cookie,
 140                         struct ceph_entity_name *locker)
 141 {
 142         int break_op_buf_size;
 143         int name_len = strlen(lock_name);
 144         int cookie_len = strlen(cookie);
 145         struct page *break_op_page;
 146         void *p, *end;
 147         int ret;
 148
 149         break_op_buf_size = name_len + sizeof(__le32) +
 150                             cookie_len + sizeof(__le32) +
 151                             sizeof(u8) + sizeof(__le64) +
 152                             CEPH_ENCODING_START_BLK_LEN;
 153         if (break_op_buf_size > PAGE_SIZE)
 154                 return -E2BIG;
 155
 156         break_op_page = alloc_page(GFP_NOIO);
 157         if (!break_op_page)
 158                 return -ENOMEM;
 159
 160         p = page_address(break_op_page);
 161         end = p + break_op_buf_size;
 162
 163         /* encode cls_lock_break_op struct */
 164         ceph_start_encoding(&p, 1, 1,
 165                             break_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
 166         ceph_encode_string(&p, end, lock_name, name_len);
 167         ceph_encode_copy(&p, locker, sizeof(*locker));
 168         ceph_encode_string(&p, end, cookie, cookie_len);
 169
 170         dout("%s lock_name %s cookie %s locker %s%llu\n", __func__, lock_name,
 171              cookie, ENTITY_NAME(*locker));
 172         ret = ceph_osdc_call(osdc, oid, oloc, "lock", "break_lock",
 173                              CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
 174                              break_op_page, break_op_buf_size, NULL, NULL);
 175
 176         dout("%s: status %d\n", __func__, ret);
 177         __free_page(break_op_page);
 178         return ret;
 179 }
 180 EXPORT_SYMBOL(ceph_cls_break_lock);
 181
 182 void ceph_free_lockers(struct ceph_locker *lockers, u32 num_lockers)
 183 {
 184         int i;
 185
 186         for (i = 0; i < num_lockers; i++)
 187                 kfree(lockers[i].id.cookie);
 188         kfree(lockers);
 189 }
 190 EXPORT_SYMBOL(ceph_free_lockers);
 191
 192 static int decode_locker(void **p, void *end, struct ceph_locker *locker)
 193 {
 194         u8 struct_v;
 195         u32 len;
 196         char *s;
 197         int ret;
 198
 199         ret = ceph_start_decoding(p, end, 1, "locker_id_t", &struct_v, &len);
 200         if (ret)
 201                 return ret;
 202
 203         ceph_decode_copy(p, &locker->id.name, sizeof(locker->id.name));
 204         s = ceph_extract_encoded_string(p, end, NULL, GFP_NOIO);
 205         if (IS_ERR(s))
 206                 return PTR_ERR(s);
 207
 208         locker->id.cookie = s;
 209
 210         ret = ceph_start_decoding(p, end, 1, "locker_info_t", &struct_v, &len);
 211         if (ret)
 212                 return ret;
 213
 214         *p += sizeof(struct ceph_timespec); /* skip expiration */
 215         ceph_decode_copy(p, &locker->info.addr, sizeof(locker->info.addr));
 216         ceph_decode_addr(&locker->info.addr);
 217         len = ceph_decode_32(p);
 218         *p += len; /* skip description */
 219
 220         dout("%s %s%llu cookie %s addr %s\n", __func__,
 221              ENTITY_NAME(locker->id.name), locker->id.cookie,
 222              ceph_pr_addr(&locker->info.addr.in_addr));
 223         return 0;
 224 }
 225
 226 static int decode_lockers(void **p, void *end, u8 *type, char **tag,
 227                           struct ceph_locker **lockers, u32 *num_lockers)
 228 {
 229         u8 struct_v;
 230         u32 struct_len;
 231         char *s;
 232         int i;
 233         int ret;
 234
 235         ret = ceph_start_decoding(p, end, 1, "cls_lock_get_info_reply",
 236                                   &struct_v, &struct_len);
 237         if (ret)
 238                 return ret;
 239
 240         *num_lockers = ceph_decode_32(p);
 241         *lockers = kcalloc(*num_lockers, sizeof(**lockers), GFP_NOIO);
 242         if (!*lockers)
 243                 return -ENOMEM;
 244
 245         for (i = 0; i < *num_lockers; i++) {
 246                 ret = decode_locker(p, end, *lockers + i);
 247                 if (ret)
 248                         goto err_free_lockers;
 249         }
 250
 251         *type = ceph_decode_8(p);
 252         s = ceph_extract_encoded_string(p, end, NULL, GFP_NOIO);
 253         if (IS_ERR(s)) {
 254                 ret = PTR_ERR(s);
 255                 goto err_free_lockers;
 256         }
 257
 258         *tag = s;
 259         return 0;
 260
 261 err_free_lockers:
 262         ceph_free_lockers(*lockers, *num_lockers);
 263         return ret;
 264 }
 265
 266 /*
 267  * On success, the caller is responsible for:
 268  *
 269  *     kfree(tag);
 270  *     ceph_free_lockers(lockers, num_lockers);
 271  */
 272 int ceph_cls_lock_info(struct ceph_osd_client *osdc,
 273                        struct ceph_object_id *oid,
 274                        struct ceph_object_locator *oloc,
 275                        char *lock_name, u8 *type, char **tag,
 276                        struct ceph_locker **lockers, u32 *num_lockers)
 277 {
 278         int get_info_op_buf_size;
 279         int name_len = strlen(lock_name);
 280         struct page *get_info_op_page, *reply_page;
 281         size_t reply_len;
 282         void *p, *end;
 283         int ret;
 284
 285         get_info_op_buf_size = name_len + sizeof(__le32) +
 286                                CEPH_ENCODING_START_BLK_LEN;
 287         if (get_info_op_buf_size > PAGE_SIZE)
 288                 return -E2BIG;
 289
 290         get_info_op_page = alloc_page(GFP_NOIO);
 291         if (!get_info_op_page)
 292                 return -ENOMEM;
 293
 294         reply_page = alloc_page(GFP_NOIO);
 295         if (!reply_page) {
 296                 __free_page(get_info_op_page);
 297                 return -ENOMEM;
 298         }
 299
 300         p = page_address(get_info_op_page);
 301         end = p + get_info_op_buf_size;
 302
 303         /* encode cls_lock_get_info_op struct */
 304         ceph_start_encoding(&p, 1, 1,
 305                             get_info_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
 306         ceph_encode_string(&p, end, lock_name, name_len);
 307
 308         dout("%s lock_name %s\n", __func__, lock_name);
 309         ret = ceph_osdc_call(osdc, oid, oloc, "lock", "get_info",
 310                              CEPH_OSD_FLAG_READ, get_info_op_page,
 311                              get_info_op_buf_size, reply_page, &reply_len);
 312
 313         dout("%s: status %d\n", __func__, ret);
 314         if (ret >= 0) {
 315                 p = page_address(reply_page);
 316                 end = p + reply_len;
 317
 318                 ret = decode_lockers(&p, end, type, tag, lockers, num_lockers);
 319         }
 320
 321         __free_page(get_info_op_page);
 322         __free_page(reply_page);
 323         return ret;
 324 }
 325 EXPORT_SYMBOL(ceph_cls_lock_info);