1 /* 2 * Ceph cache definitions. 3 * 4 * Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved. 5 * Written by Milosz Tanski (milosz@adfin.com) 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 9 * as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to: 18 * Free Software Foundation 19 * 51 Franklin Street, Fifth Floor 20 * Boston, MA 02111-1301 USA 21 * 22 */ 23 24 #include "super.h" 25 #include "cache.h" 26 27 struct ceph_aux_inode { 28 struct timespec mtime; 29 loff_t size; 30 }; 31 32 struct fscache_netfs ceph_cache_netfs = { 33 .name = "ceph", 34 .version = 0, 35 }; 36 37 static uint16_t ceph_fscache_session_get_key(const void *cookie_netfs_data, 38 void *buffer, uint16_t maxbuf) 39 { 40 const struct ceph_fs_client* fsc = cookie_netfs_data; 41 uint16_t klen; 42 43 klen = sizeof(fsc->client->fsid); 44 if (klen > maxbuf) 45 return 0; 46 47 memcpy(buffer, &fsc->client->fsid, klen); 48 return klen; 49 } 50 51 static const struct fscache_cookie_def ceph_fscache_fsid_object_def = { 52 .name = "CEPH.fsid", 53 .type = FSCACHE_COOKIE_TYPE_INDEX, 54 .get_key = ceph_fscache_session_get_key, 55 }; 56 57 int ceph_fscache_register(void) 58 { 59 return fscache_register_netfs(&ceph_cache_netfs); 60 } 61 62 void ceph_fscache_unregister(void) 63 { 64 fscache_unregister_netfs(&ceph_cache_netfs); 65 } 66 67 int ceph_fscache_register_fs(struct ceph_fs_client* fsc) 68 { 69 fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index, 70 &ceph_fscache_fsid_object_def, 71 fsc, true); 72 73 if (fsc->fscache == NULL) { 74 pr_err("Unable to resgister fsid: %p fscache cookie", fsc); 75 return 0; 76 } 77 78 fsc->revalidate_wq = alloc_workqueue("ceph-revalidate", 0, 1); 79 if (fsc->revalidate_wq == NULL) 80 return -ENOMEM; 81 82 return 0; 83 } 84 85 static uint16_t ceph_fscache_inode_get_key(const void *cookie_netfs_data, 86 void *buffer, uint16_t maxbuf) 87 { 88 const struct ceph_inode_info* ci = cookie_netfs_data; 89 uint16_t klen; 90 91 /* use ceph virtual inode (id + snaphot) */ 92 klen = sizeof(ci->i_vino); 93 if (klen > maxbuf) 94 return 0; 95 96 memcpy(buffer, &ci->i_vino, klen); 97 return klen; 98 } 99 100 static uint16_t ceph_fscache_inode_get_aux(const void *cookie_netfs_data, 101 void *buffer, uint16_t bufmax) 102 { 103 struct ceph_aux_inode aux; 104 const struct ceph_inode_info* ci = cookie_netfs_data; 105 const struct inode* inode = &ci->vfs_inode; 106 107 memset(&aux, 0, sizeof(aux)); 108 aux.mtime = inode->i_mtime; 109 aux.size = inode->i_size; 110 111 memcpy(buffer, &aux, sizeof(aux)); 112 113 return sizeof(aux); 114 } 115 116 static void ceph_fscache_inode_get_attr(const void *cookie_netfs_data, 117 uint64_t *size) 118 { 119 const struct ceph_inode_info* ci = cookie_netfs_data; 120 const struct inode* inode = &ci->vfs_inode; 121 122 *size = inode->i_size; 123 } 124 125 static enum fscache_checkaux ceph_fscache_inode_check_aux( 126 void *cookie_netfs_data, const void *data, uint16_t dlen) 127 { 128 struct ceph_aux_inode aux; 129 struct ceph_inode_info* ci = cookie_netfs_data; 130 struct inode* inode = &ci->vfs_inode; 131 132 if (dlen != sizeof(aux)) 133 return FSCACHE_CHECKAUX_OBSOLETE; 134 135 memset(&aux, 0, sizeof(aux)); 136 aux.mtime = inode->i_mtime; 137 aux.size = inode->i_size; 138 139 if (memcmp(data, &aux, sizeof(aux)) != 0) 140 return FSCACHE_CHECKAUX_OBSOLETE; 141 142 dout("ceph inode 0x%p cached okay", ci); 143 return FSCACHE_CHECKAUX_OKAY; 144 } 145 146 static void ceph_fscache_inode_now_uncached(void* cookie_netfs_data) 147 { 148 struct ceph_inode_info* ci = cookie_netfs_data; 149 struct pagevec pvec; 150 pgoff_t first; 151 int loop, nr_pages; 152 153 pagevec_init(&pvec, 0); 154 first = 0; 155 156 dout("ceph inode 0x%p now uncached", ci); 157 158 while (1) { 159 nr_pages = pagevec_lookup(&pvec, ci->vfs_inode.i_mapping, first, 160 PAGEVEC_SIZE - pagevec_count(&pvec)); 161 162 if (!nr_pages) 163 break; 164 165 for (loop = 0; loop < nr_pages; loop++) 166 ClearPageFsCache(pvec.pages[loop]); 167 168 first = pvec.pages[nr_pages - 1]->index + 1; 169 170 pvec.nr = nr_pages; 171 pagevec_release(&pvec); 172 cond_resched(); 173 } 174 } 175 176 static const struct fscache_cookie_def ceph_fscache_inode_object_def = { 177 .name = "CEPH.inode", 178 .type = FSCACHE_COOKIE_TYPE_DATAFILE, 179 .get_key = ceph_fscache_inode_get_key, 180 .get_attr = ceph_fscache_inode_get_attr, 181 .get_aux = ceph_fscache_inode_get_aux, 182 .check_aux = ceph_fscache_inode_check_aux, 183 .now_uncached = ceph_fscache_inode_now_uncached, 184 }; 185 186 void ceph_fscache_register_inode_cookie(struct ceph_fs_client* fsc, 187 struct ceph_inode_info* ci) 188 { 189 struct inode* inode = &ci->vfs_inode; 190 191 /* No caching for filesystem */ 192 if (fsc->fscache == NULL) 193 return; 194 195 /* Only cache for regular files that are read only */ 196 if ((ci->vfs_inode.i_mode & S_IFREG) == 0) 197 return; 198 199 /* Avoid multiple racing open requests */ 200 mutex_lock(&inode->i_mutex); 201 202 if (ci->fscache) 203 goto done; 204 205 ci->fscache = fscache_acquire_cookie(fsc->fscache, 206 &ceph_fscache_inode_object_def, 207 ci, true); 208 done: 209 mutex_unlock(&inode->i_mutex); 210 211 } 212 213 void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci) 214 { 215 struct fscache_cookie* cookie; 216 217 if ((cookie = ci->fscache) == NULL) 218 return; 219 220 ci->fscache = NULL; 221 222 fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode); 223 fscache_relinquish_cookie(cookie, 0); 224 } 225 226 static void ceph_vfs_readpage_complete(struct page *page, void *data, int error) 227 { 228 if (!error) 229 SetPageUptodate(page); 230 } 231 232 static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int error) 233 { 234 if (!error) 235 SetPageUptodate(page); 236 237 unlock_page(page); 238 } 239 240 static inline int cache_valid(struct ceph_inode_info *ci) 241 { 242 return ((ceph_caps_issued(ci) & CEPH_CAP_FILE_CACHE) && 243 (ci->i_fscache_gen == ci->i_rdcache_gen)); 244 } 245 246 247 /* Atempt to read from the fscache, 248 * 249 * This function is called from the readpage_nounlock context. DO NOT attempt to 250 * unlock the page here (or in the callback). 251 */ 252 int ceph_readpage_from_fscache(struct inode *inode, struct page *page) 253 { 254 struct ceph_inode_info *ci = ceph_inode(inode); 255 int ret; 256 257 if (!cache_valid(ci)) 258 return -ENOBUFS; 259 260 ret = fscache_read_or_alloc_page(ci->fscache, page, 261 ceph_vfs_readpage_complete, NULL, 262 GFP_KERNEL); 263 264 switch (ret) { 265 case 0: /* Page found */ 266 dout("page read submitted\n"); 267 return 0; 268 case -ENOBUFS: /* Pages were not found, and can't be */ 269 case -ENODATA: /* Pages were not found */ 270 dout("page/inode not in cache\n"); 271 return ret; 272 default: 273 dout("%s: unknown error ret = %i\n", __func__, ret); 274 return ret; 275 } 276 } 277 278 int ceph_readpages_from_fscache(struct inode *inode, 279 struct address_space *mapping, 280 struct list_head *pages, 281 unsigned *nr_pages) 282 { 283 struct ceph_inode_info *ci = ceph_inode(inode); 284 int ret; 285 286 if (!cache_valid(ci)) 287 return -ENOBUFS; 288 289 ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages, 290 ceph_vfs_readpage_complete_unlock, 291 NULL, mapping_gfp_mask(mapping)); 292 293 switch (ret) { 294 case 0: /* All pages found */ 295 dout("all-page read submitted\n"); 296 return 0; 297 case -ENOBUFS: /* Some pages were not found, and can't be */ 298 case -ENODATA: /* some pages were not found */ 299 dout("page/inode not in cache\n"); 300 return ret; 301 default: 302 dout("%s: unknown error ret = %i\n", __func__, ret); 303 return ret; 304 } 305 } 306 307 void ceph_readpage_to_fscache(struct inode *inode, struct page *page) 308 { 309 struct ceph_inode_info *ci = ceph_inode(inode); 310 int ret; 311 312 if (!PageFsCache(page)) 313 return; 314 315 if (!cache_valid(ci)) 316 return; 317 318 ret = fscache_write_page(ci->fscache, page, GFP_KERNEL); 319 if (ret) 320 fscache_uncache_page(ci->fscache, page); 321 } 322 323 void ceph_invalidate_fscache_page(struct inode* inode, struct page *page) 324 { 325 struct ceph_inode_info *ci = ceph_inode(inode); 326 327 if (!PageFsCache(page)) 328 return; 329 330 fscache_wait_on_page_write(ci->fscache, page); 331 fscache_uncache_page(ci->fscache, page); 332 } 333 334 void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc) 335 { 336 if (fsc->revalidate_wq) 337 destroy_workqueue(fsc->revalidate_wq); 338 339 fscache_relinquish_cookie(fsc->fscache, 0); 340 fsc->fscache = NULL; 341 } 342 343 static void ceph_revalidate_work(struct work_struct *work) 344 { 345 int issued; 346 u32 orig_gen; 347 struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info, 348 i_revalidate_work); 349 struct inode *inode = &ci->vfs_inode; 350 351 spin_lock(&ci->i_ceph_lock); 352 issued = __ceph_caps_issued(ci, NULL); 353 orig_gen = ci->i_rdcache_gen; 354 spin_unlock(&ci->i_ceph_lock); 355 356 if (!(issued & CEPH_CAP_FILE_CACHE)) { 357 dout("revalidate_work lost cache before validation %p\n", 358 inode); 359 goto out; 360 } 361 362 if (!fscache_check_consistency(ci->fscache)) 363 fscache_invalidate(ci->fscache); 364 365 spin_lock(&ci->i_ceph_lock); 366 /* Update the new valid generation (backwards sanity check too) */ 367 if (orig_gen > ci->i_fscache_gen) { 368 ci->i_fscache_gen = orig_gen; 369 } 370 spin_unlock(&ci->i_ceph_lock); 371 372 out: 373 iput(&ci->vfs_inode); 374 } 375 376 void ceph_queue_revalidate(struct inode *inode) 377 { 378 struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb); 379 struct ceph_inode_info *ci = ceph_inode(inode); 380 381 if (fsc->revalidate_wq == NULL || ci->fscache == NULL) 382 return; 383 384 ihold(inode); 385 386 if (queue_work(ceph_sb_to_client(inode->i_sb)->revalidate_wq, 387 &ci->i_revalidate_work)) { 388 dout("ceph_queue_revalidate %p\n", inode); 389 } else { 390 dout("ceph_queue_revalidate %p failed\n)", inode); 391 iput(inode); 392 } 393 } 394 395 void ceph_fscache_inode_init(struct ceph_inode_info *ci) 396 { 397 ci->fscache = NULL; 398 /* The first load is verifed cookie open time */ 399 ci->i_fscache_gen = 1; 400 INIT_WORK(&ci->i_revalidate_work, ceph_revalidate_work); 401 } 402