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 #define PNFS_DEVICE_RETRY_TIMEOUT (120*HZ) 47 48 static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE]; 49 static DEFINE_SPINLOCK(nfs4_deviceid_lock); 50 51 #ifdef NFS_DEBUG 52 void 53 nfs4_print_deviceid(const struct nfs4_deviceid *id) 54 { 55 u32 *p = (u32 *)id; 56 57 dprintk("%s: device id= [%x%x%x%x]\n", __func__, 58 p[0], p[1], p[2], p[3]); 59 } 60 EXPORT_SYMBOL_GPL(nfs4_print_deviceid); 61 #endif 62 63 static inline u32 64 nfs4_deviceid_hash(const struct nfs4_deviceid *id) 65 { 66 unsigned char *cptr = (unsigned char *)id->data; 67 unsigned int nbytes = NFS4_DEVICEID4_SIZE; 68 u32 x = 0; 69 70 while (nbytes--) { 71 x *= 37; 72 x += *cptr++; 73 } 74 return x & NFS4_DEVICE_ID_HASH_MASK; 75 } 76 77 static struct nfs4_deviceid_node * 78 _lookup_deviceid(const struct pnfs_layoutdriver_type *ld, 79 const struct nfs_client *clp, const struct nfs4_deviceid *id, 80 long hash) 81 { 82 struct nfs4_deviceid_node *d; 83 84 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node) 85 if (d->ld == ld && d->nfs_client == clp && 86 !memcmp(&d->deviceid, id, sizeof(*id))) { 87 if (atomic_read(&d->ref)) 88 return d; 89 else 90 continue; 91 } 92 return NULL; 93 } 94 95 static struct nfs4_deviceid_node * 96 nfs4_get_device_info(struct nfs_server *server, 97 const struct nfs4_deviceid *dev_id, 98 struct rpc_cred *cred, gfp_t gfp_flags) 99 { 100 struct nfs4_deviceid_node *d = NULL; 101 struct pnfs_device *pdev = NULL; 102 struct page **pages = NULL; 103 u32 max_resp_sz; 104 int max_pages; 105 int rc, i; 106 107 /* 108 * Use the session max response size as the basis for setting 109 * GETDEVICEINFO's maxcount 110 */ 111 max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz; 112 if (server->pnfs_curr_ld->max_deviceinfo_size && 113 server->pnfs_curr_ld->max_deviceinfo_size < max_resp_sz) 114 max_resp_sz = server->pnfs_curr_ld->max_deviceinfo_size; 115 max_pages = nfs_page_array_len(0, max_resp_sz); 116 dprintk("%s: server %p max_resp_sz %u max_pages %d\n", 117 __func__, server, max_resp_sz, max_pages); 118 119 pdev = kzalloc(sizeof(*pdev), gfp_flags); 120 if (!pdev) 121 return NULL; 122 123 pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags); 124 if (!pages) 125 goto out_free_pdev; 126 127 for (i = 0; i < max_pages; i++) { 128 pages[i] = alloc_page(gfp_flags); 129 if (!pages[i]) 130 goto out_free_pages; 131 } 132 133 memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id)); 134 pdev->layout_type = server->pnfs_curr_ld->id; 135 pdev->pages = pages; 136 pdev->pgbase = 0; 137 pdev->pglen = max_resp_sz; 138 pdev->mincount = 0; 139 pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead; 140 141 rc = nfs4_proc_getdeviceinfo(server, pdev, cred); 142 dprintk("%s getdevice info returns %d\n", __func__, rc); 143 if (rc) 144 goto out_free_pages; 145 146 /* 147 * Found new device, need to decode it and then add it to the 148 * list of known devices for this mountpoint. 149 */ 150 d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev, 151 gfp_flags); 152 if (d && pdev->nocache) 153 set_bit(NFS_DEVICEID_NOCACHE, &d->flags); 154 155 out_free_pages: 156 for (i = 0; i < max_pages; i++) 157 __free_page(pages[i]); 158 kfree(pages); 159 out_free_pdev: 160 kfree(pdev); 161 dprintk("<-- %s d %p\n", __func__, d); 162 return d; 163 } 164 165 /* 166 * Lookup a deviceid in cache and get a reference count on it if found 167 * 168 * @clp nfs_client associated with deviceid 169 * @id deviceid to look up 170 */ 171 static struct nfs4_deviceid_node * 172 __nfs4_find_get_deviceid(struct nfs_server *server, 173 const struct nfs4_deviceid *id, long hash) 174 { 175 struct nfs4_deviceid_node *d; 176 177 rcu_read_lock(); 178 d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id, 179 hash); 180 if (d != NULL && !atomic_inc_not_zero(&d->ref)) 181 d = NULL; 182 rcu_read_unlock(); 183 return d; 184 } 185 186 struct nfs4_deviceid_node * 187 nfs4_find_get_deviceid(struct nfs_server *server, 188 const struct nfs4_deviceid *id, struct rpc_cred *cred, 189 gfp_t gfp_mask) 190 { 191 long hash = nfs4_deviceid_hash(id); 192 struct nfs4_deviceid_node *d, *new; 193 194 d = __nfs4_find_get_deviceid(server, id, hash); 195 if (d) 196 return d; 197 198 new = nfs4_get_device_info(server, id, cred, gfp_mask); 199 if (!new) 200 return new; 201 202 spin_lock(&nfs4_deviceid_lock); 203 d = __nfs4_find_get_deviceid(server, id, hash); 204 if (d) { 205 spin_unlock(&nfs4_deviceid_lock); 206 server->pnfs_curr_ld->free_deviceid_node(new); 207 return d; 208 } 209 hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]); 210 atomic_inc(&new->ref); 211 spin_unlock(&nfs4_deviceid_lock); 212 213 return new; 214 } 215 EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid); 216 217 /* 218 * Remove a deviceid from cache 219 * 220 * @clp nfs_client associated with deviceid 221 * @id the deviceid to unhash 222 * 223 * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise. 224 */ 225 void 226 nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld, 227 const struct nfs_client *clp, const struct nfs4_deviceid *id) 228 { 229 struct nfs4_deviceid_node *d; 230 231 spin_lock(&nfs4_deviceid_lock); 232 rcu_read_lock(); 233 d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id)); 234 rcu_read_unlock(); 235 if (!d) { 236 spin_unlock(&nfs4_deviceid_lock); 237 return; 238 } 239 hlist_del_init_rcu(&d->node); 240 clear_bit(NFS_DEVICEID_NOCACHE, &d->flags); 241 spin_unlock(&nfs4_deviceid_lock); 242 243 /* balance the initial ref set in pnfs_insert_deviceid */ 244 nfs4_put_deviceid_node(d); 245 } 246 EXPORT_SYMBOL_GPL(nfs4_delete_deviceid); 247 248 void 249 nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server, 250 const struct nfs4_deviceid *id) 251 { 252 INIT_HLIST_NODE(&d->node); 253 INIT_HLIST_NODE(&d->tmpnode); 254 d->ld = server->pnfs_curr_ld; 255 d->nfs_client = server->nfs_client; 256 d->flags = 0; 257 d->deviceid = *id; 258 atomic_set(&d->ref, 1); 259 } 260 EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node); 261 262 /* 263 * Dereference a deviceid node and delete it when its reference count drops 264 * to zero. 265 * 266 * @d deviceid node to put 267 * 268 * return true iff the node was deleted 269 * Note that since the test for d->ref == 0 is sufficient to establish 270 * that the node is no longer hashed in the global device id cache. 271 */ 272 bool 273 nfs4_put_deviceid_node(struct nfs4_deviceid_node *d) 274 { 275 if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) { 276 if (atomic_add_unless(&d->ref, -1, 2)) 277 return false; 278 nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid); 279 } 280 if (!atomic_dec_and_test(&d->ref)) 281 return false; 282 d->ld->free_deviceid_node(d); 283 return true; 284 } 285 EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node); 286 287 void 288 nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node) 289 { 290 node->timestamp_unavailable = jiffies; 291 set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags); 292 } 293 EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable); 294 295 bool 296 nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node) 297 { 298 if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) { 299 unsigned long start, end; 300 301 end = jiffies; 302 start = end - PNFS_DEVICE_RETRY_TIMEOUT; 303 if (time_in_range(node->timestamp_unavailable, start, end)) 304 return true; 305 clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags); 306 } 307 return false; 308 } 309 EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable); 310 311 static void 312 _deviceid_purge_client(const struct nfs_client *clp, long hash) 313 { 314 struct nfs4_deviceid_node *d; 315 HLIST_HEAD(tmp); 316 317 spin_lock(&nfs4_deviceid_lock); 318 rcu_read_lock(); 319 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node) 320 if (d->nfs_client == clp && atomic_read(&d->ref)) { 321 hlist_del_init_rcu(&d->node); 322 hlist_add_head(&d->tmpnode, &tmp); 323 clear_bit(NFS_DEVICEID_NOCACHE, &d->flags); 324 } 325 rcu_read_unlock(); 326 spin_unlock(&nfs4_deviceid_lock); 327 328 if (hlist_empty(&tmp)) 329 return; 330 331 while (!hlist_empty(&tmp)) { 332 d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode); 333 hlist_del(&d->tmpnode); 334 nfs4_put_deviceid_node(d); 335 } 336 } 337 338 void 339 nfs4_deviceid_purge_client(const struct nfs_client *clp) 340 { 341 long h; 342 343 if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS)) 344 return; 345 for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++) 346 _deviceid_purge_client(clp, h); 347 } 348 349 /* 350 * Stop use of all deviceids associated with an nfs_client 351 */ 352 void 353 nfs4_deviceid_mark_client_invalid(struct nfs_client *clp) 354 { 355 struct nfs4_deviceid_node *d; 356 int i; 357 358 rcu_read_lock(); 359 for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){ 360 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node) 361 if (d->nfs_client == clp) 362 set_bit(NFS_DEVICEID_INVALID, &d->flags); 363 } 364 rcu_read_unlock(); 365 } 366