1 /* 2 * Device operations for the pnfs client. 3 * 4 * Copyright (c) 2002 5 * The Regents of the University of Michigan 6 * All Rights Reserved 7 * 8 * Dean Hildebrand <dhildebz@umich.edu> 9 * Garth Goodson <Garth.Goodson@netapp.com> 10 * 11 * Permission is granted to use, copy, create derivative works, and 12 * redistribute this software and such derivative works for any purpose, 13 * so long as the name of the University of Michigan is not used in 14 * any advertising or publicity pertaining to the use or distribution 15 * of this software without specific, written prior authorization. If 16 * the above copyright notice or any other identification of the 17 * University of Michigan is included in any copy of any portion of 18 * this software, then the disclaimer below must also be included. 19 * 20 * This software is provided as is, without representation or warranty 21 * of any kind either express or implied, including without limitation 22 * the implied warranties of merchantability, fitness for a particular 23 * purpose, or noninfringement. The Regents of the University of 24 * Michigan shall not be liable for any damages, including special, 25 * indirect, incidental, or consequential damages, with respect to any 26 * claim arising out of or in connection with the use of the software, 27 * even if it has been or is hereafter advised of the possibility of 28 * such damages. 29 */ 30 31 #include <linux/export.h> 32 #include <linux/nfs_fs.h> 33 #include "nfs4session.h" 34 #include "internal.h" 35 #include "pnfs.h" 36 37 #define NFSDBG_FACILITY NFSDBG_PNFS 38 39 /* 40 * Device ID RCU cache. A device ID is unique per server and layout type. 41 */ 42 #define NFS4_DEVICE_ID_HASH_BITS 5 43 #define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS) 44 #define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1) 45 46 47 static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE]; 48 static DEFINE_SPINLOCK(nfs4_deviceid_lock); 49 50 #ifdef NFS_DEBUG 51 void 52 nfs4_print_deviceid(const struct nfs4_deviceid *id) 53 { 54 u32 *p = (u32 *)id; 55 56 dprintk("%s: device id= [%x%x%x%x]\n", __func__, 57 p[0], p[1], p[2], p[3]); 58 } 59 EXPORT_SYMBOL_GPL(nfs4_print_deviceid); 60 #endif 61 62 static inline u32 63 nfs4_deviceid_hash(const struct nfs4_deviceid *id) 64 { 65 unsigned char *cptr = (unsigned char *)id->data; 66 unsigned int nbytes = NFS4_DEVICEID4_SIZE; 67 u32 x = 0; 68 69 while (nbytes--) { 70 x *= 37; 71 x += *cptr++; 72 } 73 return x & NFS4_DEVICE_ID_HASH_MASK; 74 } 75 76 static struct nfs4_deviceid_node * 77 _lookup_deviceid(const struct pnfs_layoutdriver_type *ld, 78 const struct nfs_client *clp, const struct nfs4_deviceid *id, 79 long hash) 80 { 81 struct nfs4_deviceid_node *d; 82 83 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node) 84 if (d->ld == ld && d->nfs_client == clp && 85 !memcmp(&d->deviceid, id, sizeof(*id))) { 86 if (atomic_read(&d->ref)) 87 return d; 88 else 89 continue; 90 } 91 return NULL; 92 } 93 94 static struct nfs4_deviceid_node * 95 nfs4_get_device_info(struct nfs_server *server, 96 const struct nfs4_deviceid *dev_id, 97 const struct cred *cred, gfp_t gfp_flags) 98 { 99 struct nfs4_deviceid_node *d = NULL; 100 struct pnfs_device *pdev = NULL; 101 struct page **pages = NULL; 102 u32 max_resp_sz; 103 int max_pages; 104 int rc, i; 105 106 /* 107 * Use the session max response size as the basis for setting 108 * GETDEVICEINFO's maxcount 109 */ 110 max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz; 111 if (server->pnfs_curr_ld->max_deviceinfo_size && 112 server->pnfs_curr_ld->max_deviceinfo_size < max_resp_sz) 113 max_resp_sz = server->pnfs_curr_ld->max_deviceinfo_size; 114 max_pages = nfs_page_array_len(0, max_resp_sz); 115 dprintk("%s: server %p max_resp_sz %u max_pages %d\n", 116 __func__, server, max_resp_sz, max_pages); 117 118 pdev = kzalloc(sizeof(*pdev), gfp_flags); 119 if (!pdev) 120 return NULL; 121 122 pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags); 123 if (!pages) 124 goto out_free_pdev; 125 126 for (i = 0; i < max_pages; i++) { 127 pages[i] = alloc_page(gfp_flags); 128 if (!pages[i]) 129 goto out_free_pages; 130 } 131 132 memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id)); 133 pdev->layout_type = server->pnfs_curr_ld->id; 134 pdev->pages = pages; 135 pdev->pgbase = 0; 136 pdev->pglen = max_resp_sz; 137 pdev->mincount = 0; 138 pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead; 139 140 rc = nfs4_proc_getdeviceinfo(server, pdev, cred); 141 dprintk("%s getdevice info returns %d\n", __func__, rc); 142 if (rc) 143 goto out_free_pages; 144 145 /* 146 * Found new device, need to decode it and then add it to the 147 * list of known devices for this mountpoint. 148 */ 149 d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev, 150 gfp_flags); 151 if (d && pdev->nocache) 152 set_bit(NFS_DEVICEID_NOCACHE, &d->flags); 153 154 out_free_pages: 155 for (i = 0; i < max_pages; i++) 156 __free_page(pages[i]); 157 kfree(pages); 158 out_free_pdev: 159 kfree(pdev); 160 dprintk("<-- %s d %p\n", __func__, d); 161 return d; 162 } 163 164 /* 165 * Lookup a deviceid in cache and get a reference count on it if found 166 * 167 * @clp nfs_client associated with deviceid 168 * @id deviceid to look up 169 */ 170 static struct nfs4_deviceid_node * 171 __nfs4_find_get_deviceid(struct nfs_server *server, 172 const struct nfs4_deviceid *id, long hash) 173 { 174 struct nfs4_deviceid_node *d; 175 176 rcu_read_lock(); 177 d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id, 178 hash); 179 if (d != NULL && !atomic_inc_not_zero(&d->ref)) 180 d = NULL; 181 rcu_read_unlock(); 182 return d; 183 } 184 185 struct nfs4_deviceid_node * 186 nfs4_find_get_deviceid(struct nfs_server *server, 187 const struct nfs4_deviceid *id, const struct cred *cred, 188 gfp_t gfp_mask) 189 { 190 long hash = nfs4_deviceid_hash(id); 191 struct nfs4_deviceid_node *d, *new; 192 193 d = __nfs4_find_get_deviceid(server, id, hash); 194 if (d) 195 return d; 196 197 new = nfs4_get_device_info(server, id, cred, gfp_mask); 198 if (!new) 199 return new; 200 201 spin_lock(&nfs4_deviceid_lock); 202 d = __nfs4_find_get_deviceid(server, id, hash); 203 if (d) { 204 spin_unlock(&nfs4_deviceid_lock); 205 server->pnfs_curr_ld->free_deviceid_node(new); 206 return d; 207 } 208 hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]); 209 atomic_inc(&new->ref); 210 spin_unlock(&nfs4_deviceid_lock); 211 212 return new; 213 } 214 EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid); 215 216 /* 217 * Remove a deviceid from cache 218 * 219 * @clp nfs_client associated with deviceid 220 * @id the deviceid to unhash 221 * 222 * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise. 223 */ 224 void 225 nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld, 226 const struct nfs_client *clp, const struct nfs4_deviceid *id) 227 { 228 struct nfs4_deviceid_node *d; 229 230 spin_lock(&nfs4_deviceid_lock); 231 rcu_read_lock(); 232 d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id)); 233 rcu_read_unlock(); 234 if (!d) { 235 spin_unlock(&nfs4_deviceid_lock); 236 return; 237 } 238 hlist_del_init_rcu(&d->node); 239 clear_bit(NFS_DEVICEID_NOCACHE, &d->flags); 240 spin_unlock(&nfs4_deviceid_lock); 241 242 /* balance the initial ref set in pnfs_insert_deviceid */ 243 nfs4_put_deviceid_node(d); 244 } 245 EXPORT_SYMBOL_GPL(nfs4_delete_deviceid); 246 247 void 248 nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server, 249 const struct nfs4_deviceid *id) 250 { 251 INIT_HLIST_NODE(&d->node); 252 INIT_HLIST_NODE(&d->tmpnode); 253 d->ld = server->pnfs_curr_ld; 254 d->nfs_client = server->nfs_client; 255 d->flags = 0; 256 d->deviceid = *id; 257 atomic_set(&d->ref, 1); 258 } 259 EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node); 260 261 /* 262 * Dereference a deviceid node and delete it when its reference count drops 263 * to zero. 264 * 265 * @d deviceid node to put 266 * 267 * return true iff the node was deleted 268 * Note that since the test for d->ref == 0 is sufficient to establish 269 * that the node is no longer hashed in the global device id cache. 270 */ 271 bool 272 nfs4_put_deviceid_node(struct nfs4_deviceid_node *d) 273 { 274 if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) { 275 if (atomic_add_unless(&d->ref, -1, 2)) 276 return false; 277 nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid); 278 } 279 if (!atomic_dec_and_test(&d->ref)) 280 return false; 281 d->ld->free_deviceid_node(d); 282 return true; 283 } 284 EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node); 285 286 void 287 nfs4_mark_deviceid_available(struct nfs4_deviceid_node *node) 288 { 289 if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) { 290 clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags); 291 smp_mb__after_atomic(); 292 } 293 } 294 EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_available); 295 296 void 297 nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node) 298 { 299 node->timestamp_unavailable = jiffies; 300 smp_mb__before_atomic(); 301 set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags); 302 smp_mb__after_atomic(); 303 } 304 EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable); 305 306 bool 307 nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node) 308 { 309 if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) { 310 unsigned long start, end; 311 312 end = jiffies; 313 start = end - PNFS_DEVICE_RETRY_TIMEOUT; 314 if (time_in_range(node->timestamp_unavailable, start, end)) 315 return true; 316 clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags); 317 smp_mb__after_atomic(); 318 } 319 return false; 320 } 321 EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable); 322 323 static void 324 _deviceid_purge_client(const struct nfs_client *clp, long hash) 325 { 326 struct nfs4_deviceid_node *d; 327 HLIST_HEAD(tmp); 328 329 spin_lock(&nfs4_deviceid_lock); 330 rcu_read_lock(); 331 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node) 332 if (d->nfs_client == clp && atomic_read(&d->ref)) { 333 hlist_del_init_rcu(&d->node); 334 hlist_add_head(&d->tmpnode, &tmp); 335 clear_bit(NFS_DEVICEID_NOCACHE, &d->flags); 336 } 337 rcu_read_unlock(); 338 spin_unlock(&nfs4_deviceid_lock); 339 340 if (hlist_empty(&tmp)) 341 return; 342 343 while (!hlist_empty(&tmp)) { 344 d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode); 345 hlist_del(&d->tmpnode); 346 nfs4_put_deviceid_node(d); 347 } 348 } 349 350 void 351 nfs4_deviceid_purge_client(const struct nfs_client *clp) 352 { 353 long h; 354 355 if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS)) 356 return; 357 for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++) 358 _deviceid_purge_client(clp, h); 359 } 360 361 /* 362 * Stop use of all deviceids associated with an nfs_client 363 */ 364 void 365 nfs4_deviceid_mark_client_invalid(struct nfs_client *clp) 366 { 367 struct nfs4_deviceid_node *d; 368 int i; 369 370 rcu_read_lock(); 371 for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){ 372 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node) 373 if (d->nfs_client == clp) 374 set_bit(NFS_DEVICEID_INVALID, &d->flags); 375 } 376 rcu_read_unlock(); 377 } 378