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 + snapshot) */ 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 = i_size_read(inode); 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 *size = i_size_read(&ci->vfs_inode); 121 } 122 123 static enum fscache_checkaux ceph_fscache_inode_check_aux( 124 void *cookie_netfs_data, const void *data, uint16_t dlen) 125 { 126 struct ceph_aux_inode aux; 127 struct ceph_inode_info* ci = cookie_netfs_data; 128 struct inode* inode = &ci->vfs_inode; 129 130 if (dlen != sizeof(aux)) 131 return FSCACHE_CHECKAUX_OBSOLETE; 132 133 memset(&aux, 0, sizeof(aux)); 134 aux.mtime = inode->i_mtime; 135 aux.size = i_size_read(inode); 136 137 if (memcmp(data, &aux, sizeof(aux)) != 0) 138 return FSCACHE_CHECKAUX_OBSOLETE; 139 140 dout("ceph inode 0x%p cached okay", ci); 141 return FSCACHE_CHECKAUX_OKAY; 142 } 143 144 static void ceph_fscache_inode_now_uncached(void* cookie_netfs_data) 145 { 146 struct ceph_inode_info* ci = cookie_netfs_data; 147 struct pagevec pvec; 148 pgoff_t first; 149 int loop, nr_pages; 150 151 pagevec_init(&pvec, 0); 152 first = 0; 153 154 dout("ceph inode 0x%p now uncached", ci); 155 156 while (1) { 157 nr_pages = pagevec_lookup(&pvec, ci->vfs_inode.i_mapping, first, 158 PAGEVEC_SIZE - pagevec_count(&pvec)); 159 160 if (!nr_pages) 161 break; 162 163 for (loop = 0; loop < nr_pages; loop++) 164 ClearPageFsCache(pvec.pages[loop]); 165 166 first = pvec.pages[nr_pages - 1]->index + 1; 167 168 pvec.nr = nr_pages; 169 pagevec_release(&pvec); 170 cond_resched(); 171 } 172 } 173 174 static const struct fscache_cookie_def ceph_fscache_inode_object_def = { 175 .name = "CEPH.inode", 176 .type = FSCACHE_COOKIE_TYPE_DATAFILE, 177 .get_key = ceph_fscache_inode_get_key, 178 .get_attr = ceph_fscache_inode_get_attr, 179 .get_aux = ceph_fscache_inode_get_aux, 180 .check_aux = ceph_fscache_inode_check_aux, 181 .now_uncached = ceph_fscache_inode_now_uncached, 182 }; 183 184 void ceph_fscache_register_inode_cookie(struct ceph_fs_client* fsc, 185 struct ceph_inode_info* ci) 186 { 187 struct inode* inode = &ci->vfs_inode; 188 189 /* No caching for filesystem */ 190 if (fsc->fscache == NULL) 191 return; 192 193 /* Only cache for regular files that are read only */ 194 if ((ci->vfs_inode.i_mode & S_IFREG) == 0) 195 return; 196 197 /* Avoid multiple racing open requests */ 198 inode_lock(inode); 199 200 if (ci->fscache) 201 goto done; 202 203 ci->fscache = fscache_acquire_cookie(fsc->fscache, 204 &ceph_fscache_inode_object_def, 205 ci, true); 206 fscache_check_consistency(ci->fscache); 207 done: 208 inode_unlock(inode); 209 210 } 211 212 void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci) 213 { 214 struct fscache_cookie* cookie; 215 216 if ((cookie = ci->fscache) == NULL) 217 return; 218 219 ci->fscache = NULL; 220 221 fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode); 222 fscache_relinquish_cookie(cookie, 0); 223 } 224 225 static void ceph_vfs_readpage_complete(struct page *page, void *data, int error) 226 { 227 if (!error) 228 SetPageUptodate(page); 229 } 230 231 static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int error) 232 { 233 if (!error) 234 SetPageUptodate(page); 235 236 unlock_page(page); 237 } 238 239 static inline int cache_valid(struct ceph_inode_info *ci) 240 { 241 return ((ceph_caps_issued(ci) & CEPH_CAP_FILE_CACHE) && 242 (ci->i_fscache_gen == ci->i_rdcache_gen)); 243 } 244 245 246 /* Atempt to read from the fscache, 247 * 248 * This function is called from the readpage_nounlock context. DO NOT attempt to 249 * unlock the page here (or in the callback). 250 */ 251 int ceph_readpage_from_fscache(struct inode *inode, struct page *page) 252 { 253 struct ceph_inode_info *ci = ceph_inode(inode); 254 int ret; 255 256 if (!cache_valid(ci)) 257 return -ENOBUFS; 258 259 ret = fscache_read_or_alloc_page(ci->fscache, page, 260 ceph_vfs_readpage_complete, NULL, 261 GFP_KERNEL); 262 263 switch (ret) { 264 case 0: /* Page found */ 265 dout("page read submitted\n"); 266 return 0; 267 case -ENOBUFS: /* Pages were not found, and can't be */ 268 case -ENODATA: /* Pages were not found */ 269 dout("page/inode not in cache\n"); 270 return ret; 271 default: 272 dout("%s: unknown error ret = %i\n", __func__, ret); 273 return ret; 274 } 275 } 276 277 int ceph_readpages_from_fscache(struct inode *inode, 278 struct address_space *mapping, 279 struct list_head *pages, 280 unsigned *nr_pages) 281 { 282 struct ceph_inode_info *ci = ceph_inode(inode); 283 int ret; 284 285 if (!cache_valid(ci)) 286 return -ENOBUFS; 287 288 ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages, 289 ceph_vfs_readpage_complete_unlock, 290 NULL, mapping_gfp_mask(mapping)); 291 292 switch (ret) { 293 case 0: /* All pages found */ 294 dout("all-page read submitted\n"); 295 return 0; 296 case -ENOBUFS: /* Some pages were not found, and can't be */ 297 case -ENODATA: /* some pages were not found */ 298 dout("page/inode not in cache\n"); 299 return ret; 300 default: 301 dout("%s: unknown error ret = %i\n", __func__, ret); 302 return ret; 303 } 304 } 305 306 void ceph_readpage_to_fscache(struct inode *inode, struct page *page) 307 { 308 struct ceph_inode_info *ci = ceph_inode(inode); 309 int ret; 310 311 if (!PageFsCache(page)) 312 return; 313 314 if (!cache_valid(ci)) 315 return; 316 317 ret = fscache_write_page(ci->fscache, page, GFP_KERNEL); 318 if (ret) 319 fscache_uncache_page(ci->fscache, page); 320 } 321 322 void ceph_invalidate_fscache_page(struct inode* inode, struct page *page) 323 { 324 struct ceph_inode_info *ci = ceph_inode(inode); 325 326 if (!PageFsCache(page)) 327 return; 328 329 fscache_wait_on_page_write(ci->fscache, page); 330 fscache_uncache_page(ci->fscache, page); 331 } 332 333 void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc) 334 { 335 if (fsc->revalidate_wq) 336 destroy_workqueue(fsc->revalidate_wq); 337 338 fscache_relinquish_cookie(fsc->fscache, 0); 339 fsc->fscache = NULL; 340 } 341 342 static void ceph_revalidate_work(struct work_struct *work) 343 { 344 int issued; 345 u32 orig_gen; 346 struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info, 347 i_revalidate_work); 348 struct inode *inode = &ci->vfs_inode; 349 350 spin_lock(&ci->i_ceph_lock); 351 issued = __ceph_caps_issued(ci, NULL); 352 orig_gen = ci->i_rdcache_gen; 353 spin_unlock(&ci->i_ceph_lock); 354 355 if (!(issued & CEPH_CAP_FILE_CACHE)) { 356 dout("revalidate_work lost cache before validation %p\n", 357 inode); 358 goto out; 359 } 360 361 if (!fscache_check_consistency(ci->fscache)) 362 fscache_invalidate(ci->fscache); 363 364 spin_lock(&ci->i_ceph_lock); 365 /* Update the new valid generation (backwards sanity check too) */ 366 if (orig_gen > ci->i_fscache_gen) { 367 ci->i_fscache_gen = orig_gen; 368 } 369 spin_unlock(&ci->i_ceph_lock); 370 371 out: 372 iput(&ci->vfs_inode); 373 } 374 375 void ceph_queue_revalidate(struct inode *inode) 376 { 377 struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb); 378 struct ceph_inode_info *ci = ceph_inode(inode); 379 380 if (fsc->revalidate_wq == NULL || ci->fscache == NULL) 381 return; 382 383 ihold(inode); 384 385 if (queue_work(ceph_sb_to_client(inode->i_sb)->revalidate_wq, 386 &ci->i_revalidate_work)) { 387 dout("ceph_queue_revalidate %p\n", inode); 388 } else { 389 dout("ceph_queue_revalidate %p failed\n)", inode); 390 iput(inode); 391 } 392 } 393 394 void ceph_fscache_inode_init(struct ceph_inode_info *ci) 395 { 396 ci->fscache = NULL; 397 /* The first load is verifed cookie open time */ 398 ci->i_fscache_gen = 1; 399 INIT_WORK(&ci->i_revalidate_work, ceph_revalidate_work); 400 } 401