4 * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
7 #include <linux/kernel.h>
8 #include <linux/errno.h>
9 #include <linux/string.h>
10 #include <linux/printk.h>
11 #include <linux/slab.h>
12 #include <linux/sunrpc/sched.h>
13 #include <linux/sunrpc/bc_xprt.h>
14 #include <linux/nfs.h>
15 #include <linux/nfs4.h>
16 #include <linux/nfs_fs.h>
17 #include <linux/module.h>
21 #include "nfs4session.h"
24 #define NFSDBG_FACILITY NFSDBG_STATE
27 * nfs4_shrink_slot_table - free retired slots from the slot table
29 static void nfs4_shrink_slot_table(struct nfs4_slot_table *tbl, u32 newsize)
32 if (newsize >= tbl->max_slots)
39 struct nfs4_slot *slot = *p;
48 * nfs4_free_slot - free a slot and efficiently update slot table.
50 * freeing a slot is trivially done by clearing its respective bit
52 * If the freed slotid equals highest_used_slotid we want to update it
53 * so that the server would be able to size down the slot table if needed,
54 * otherwise we know that the highest_used_slotid is still in use.
55 * When updating highest_used_slotid there may be "holes" in the bitmap
56 * so we need to scan down from highest_used_slotid to 0 looking for the now
57 * highest slotid in use.
58 * If none found, highest_used_slotid is set to NFS4_NO_SLOT.
60 * Must be called while holding tbl->slot_tbl_lock
62 void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot)
64 u32 slotid = slot->slot_nr;
66 /* clear used bit in bitmap */
67 __clear_bit(slotid, tbl->used_slots);
69 /* update highest_used_slotid when it is freed */
70 if (slotid == tbl->highest_used_slotid) {
71 u32 new_max = find_last_bit(tbl->used_slots, slotid);
73 tbl->highest_used_slotid = new_max;
75 tbl->highest_used_slotid = NFS4_NO_SLOT;
76 nfs4_session_drain_complete(tbl->session, tbl);
79 dprintk("%s: slotid %u highest_used_slotid %d\n", __func__,
80 slotid, tbl->highest_used_slotid);
83 static struct nfs4_slot *nfs4_new_slot(struct nfs4_slot_table *tbl,
84 u32 slotid, u32 seq_init, gfp_t gfp_mask)
86 struct nfs4_slot *slot;
88 slot = kzalloc(sizeof(*slot), gfp_mask);
91 slot->slot_nr = slotid;
92 slot->seq_nr = seq_init;
97 static struct nfs4_slot *nfs4_find_or_create_slot(struct nfs4_slot_table *tbl,
98 u32 slotid, u32 seq_init, gfp_t gfp_mask)
100 struct nfs4_slot **p, *slot;
105 *p = nfs4_new_slot(tbl, tbl->max_slots,
112 if (slot->slot_nr == slotid)
116 return ERR_PTR(-ENOMEM);
120 * nfs4_alloc_slot - efficiently look for a free slot
122 * nfs4_alloc_slot looks for an unset bit in the used_slots bitmap.
123 * If found, we mark the slot as used, update the highest_used_slotid,
124 * and respectively set up the sequence operation args.
126 * Note: must be called with under the slot_tbl_lock.
128 struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl)
130 struct nfs4_slot *ret = ERR_PTR(-EBUSY);
133 dprintk("--> %s used_slots=%04lx highest_used=%u max_slots=%u\n",
134 __func__, tbl->used_slots[0], tbl->highest_used_slotid,
135 tbl->max_slotid + 1);
136 slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1);
137 if (slotid > tbl->max_slotid)
139 ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
142 __set_bit(slotid, tbl->used_slots);
143 if (slotid > tbl->highest_used_slotid ||
144 tbl->highest_used_slotid == NFS4_NO_SLOT)
145 tbl->highest_used_slotid = slotid;
146 ret->renewal_time = jiffies;
147 ret->generation = tbl->generation;
150 dprintk("<-- %s used_slots=%04lx highest_used=%d slotid=%d \n",
151 __func__, tbl->used_slots[0], tbl->highest_used_slotid,
152 !IS_ERR(ret) ? ret->slot_nr : -1);
156 static int nfs4_grow_slot_table(struct nfs4_slot_table *tbl,
157 u32 max_reqs, u32 ivalue)
159 if (max_reqs <= tbl->max_slots)
161 if (!IS_ERR(nfs4_find_or_create_slot(tbl, max_reqs - 1, ivalue, GFP_NOFS)))
166 static void nfs4_reset_slot_table(struct nfs4_slot_table *tbl,
167 u32 server_highest_slotid,
170 struct nfs4_slot **p;
172 nfs4_shrink_slot_table(tbl, server_highest_slotid + 1);
175 (*p)->seq_nr = ivalue;
178 tbl->highest_used_slotid = NFS4_NO_SLOT;
179 tbl->target_highest_slotid = server_highest_slotid;
180 tbl->server_highest_slotid = server_highest_slotid;
181 tbl->max_slotid = server_highest_slotid;
185 * (re)Initialise a slot table
187 static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl,
188 u32 max_reqs, u32 ivalue)
192 dprintk("--> %s: max_reqs=%u, tbl->max_slots %d\n", __func__,
193 max_reqs, tbl->max_slots);
195 if (max_reqs > NFS4_MAX_SLOT_TABLE)
196 max_reqs = NFS4_MAX_SLOT_TABLE;
198 ret = nfs4_grow_slot_table(tbl, max_reqs, ivalue);
202 spin_lock(&tbl->slot_tbl_lock);
203 nfs4_reset_slot_table(tbl, max_reqs - 1, ivalue);
204 spin_unlock(&tbl->slot_tbl_lock);
206 dprintk("%s: tbl=%p slots=%p max_slots=%d\n", __func__,
207 tbl, tbl->slots, tbl->max_slots);
209 dprintk("<-- %s: return %d\n", __func__, ret);
213 /* Destroy the slot table */
214 static void nfs4_destroy_slot_tables(struct nfs4_session *session)
216 nfs4_shrink_slot_table(&session->fc_slot_table, 0);
217 nfs4_shrink_slot_table(&session->bc_slot_table, 0);
220 /* Update the client's idea of target_highest_slotid */
221 static void nfs41_set_target_slotid_locked(struct nfs4_slot_table *tbl,
222 u32 target_highest_slotid)
224 unsigned int max_slotid, i;
226 if (tbl->target_highest_slotid == target_highest_slotid)
228 tbl->target_highest_slotid = target_highest_slotid;
231 max_slotid = min(NFS4_MAX_SLOT_TABLE - 1, tbl->target_highest_slotid);
232 for (i = tbl->max_slotid + 1; i <= max_slotid; i++)
233 rpc_wake_up_next(&tbl->slot_tbl_waitq);
234 tbl->max_slotid = max_slotid;
237 void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
238 u32 target_highest_slotid)
240 spin_lock(&tbl->slot_tbl_lock);
241 nfs41_set_target_slotid_locked(tbl, target_highest_slotid);
242 spin_unlock(&tbl->slot_tbl_lock);
245 static void nfs41_set_server_slotid_locked(struct nfs4_slot_table *tbl,
248 if (tbl->server_highest_slotid == highest_slotid)
250 if (tbl->highest_used_slotid > highest_slotid)
252 /* Deallocate slots */
253 nfs4_shrink_slot_table(tbl, highest_slotid + 1);
254 tbl->server_highest_slotid = highest_slotid;
257 void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
258 struct nfs4_slot *slot,
259 struct nfs4_sequence_res *res)
261 spin_lock(&tbl->slot_tbl_lock);
262 if (tbl->generation != slot->generation)
264 nfs41_set_server_slotid_locked(tbl, res->sr_highest_slotid);
265 nfs41_set_target_slotid_locked(tbl, res->sr_target_highest_slotid);
267 spin_unlock(&tbl->slot_tbl_lock);
271 * Initialize or reset the forechannel and backchannel tables
273 int nfs4_setup_session_slot_tables(struct nfs4_session *ses)
275 struct nfs4_slot_table *tbl;
278 dprintk("--> %s\n", __func__);
280 tbl = &ses->fc_slot_table;
282 status = nfs4_realloc_slot_table(tbl, ses->fc_attrs.max_reqs, 1);
283 if (status) /* -ENOMEM */
286 tbl = &ses->bc_slot_table;
288 status = nfs4_realloc_slot_table(tbl, ses->bc_attrs.max_reqs, 0);
289 if (status && tbl->slots == NULL)
290 /* Fore and back channel share a connection so get
291 * both slot tables or neither */
292 nfs4_destroy_slot_tables(ses);
296 struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
298 struct nfs4_session *session;
299 struct nfs4_slot_table *tbl;
301 session = kzalloc(sizeof(struct nfs4_session), GFP_NOFS);
305 tbl = &session->fc_slot_table;
306 tbl->highest_used_slotid = NFS4_NO_SLOT;
307 spin_lock_init(&tbl->slot_tbl_lock);
308 rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, "ForeChannel Slot table");
309 init_completion(&tbl->complete);
311 tbl = &session->bc_slot_table;
312 tbl->highest_used_slotid = NFS4_NO_SLOT;
313 spin_lock_init(&tbl->slot_tbl_lock);
314 rpc_init_wait_queue(&tbl->slot_tbl_waitq, "BackChannel Slot table");
315 init_completion(&tbl->complete);
317 session->session_state = 1<<NFS4_SESSION_INITING;
323 void nfs4_destroy_session(struct nfs4_session *session)
325 struct rpc_xprt *xprt;
326 struct rpc_cred *cred;
328 cred = nfs4_get_exchange_id_cred(session->clp);
329 nfs4_proc_destroy_session(session, cred);
334 xprt = rcu_dereference(session->clp->cl_rpcclient->cl_xprt);
336 dprintk("%s Destroy backchannel for xprt %p\n",
338 xprt_destroy_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
339 nfs4_destroy_slot_tables(session);
344 * With sessions, the client is not marked ready until after a
345 * successful EXCHANGE_ID and CREATE_SESSION.
347 * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate
348 * other versions of NFS can be tried.
350 static int nfs41_check_session_ready(struct nfs_client *clp)
354 if (clp->cl_cons_state == NFS_CS_SESSION_INITING) {
355 ret = nfs4_client_recover_expired_lease(clp);
359 if (clp->cl_cons_state < NFS_CS_READY)
360 return -EPROTONOSUPPORT;
365 int nfs4_init_session(struct nfs_server *server)
367 struct nfs_client *clp = server->nfs_client;
368 struct nfs4_session *session;
369 unsigned int target_max_rqst_sz = NFS_MAX_FILE_IO_SIZE;
370 unsigned int target_max_resp_sz = NFS_MAX_FILE_IO_SIZE;
372 if (!nfs4_has_session(clp))
375 if (server->rsize != 0)
376 target_max_resp_sz = server->rsize;
377 target_max_resp_sz += nfs41_maxread_overhead;
379 if (server->wsize != 0)
380 target_max_rqst_sz = server->wsize;
381 target_max_rqst_sz += nfs41_maxwrite_overhead;
383 session = clp->cl_session;
384 spin_lock(&clp->cl_lock);
385 if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) {
386 /* Initialise targets and channel attributes */
387 session->fc_target_max_rqst_sz = target_max_rqst_sz;
388 session->fc_attrs.max_rqst_sz = target_max_rqst_sz;
389 session->fc_target_max_resp_sz = target_max_resp_sz;
390 session->fc_attrs.max_resp_sz = target_max_resp_sz;
392 /* Just adjust the targets */
393 if (target_max_rqst_sz > session->fc_target_max_rqst_sz) {
394 session->fc_target_max_rqst_sz = target_max_rqst_sz;
395 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
397 if (target_max_resp_sz > session->fc_target_max_resp_sz) {
398 session->fc_target_max_resp_sz = target_max_resp_sz;
399 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
402 spin_unlock(&clp->cl_lock);
404 if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
405 nfs4_schedule_lease_recovery(clp);
407 return nfs41_check_session_ready(clp);
410 int nfs4_init_ds_session(struct nfs_client *clp, unsigned long lease_time)
412 struct nfs4_session *session = clp->cl_session;
415 spin_lock(&clp->cl_lock);
416 if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) {
418 * Do not set NFS_CS_CHECK_LEASE_TIME instead set the
419 * DS lease to be equal to the MDS lease.
421 clp->cl_lease_time = lease_time;
422 clp->cl_last_renewal = jiffies;
424 spin_unlock(&clp->cl_lock);
426 ret = nfs41_check_session_ready(clp);
429 /* Test for the DS role */
430 if (!is_ds_client(clp))
434 EXPORT_SYMBOL_GPL(nfs4_init_ds_session);