diff options
author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-11-26 21:49:34 +0400 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-12-06 03:30:45 +0400 |
commit | 73e39aaa8366694450cd6034050f542f965e277d (patch) | |
tree | df731a81afdd826a401f611dd85c9cf08a9cd0c1 /fs/nfs/nfs4session.c | |
parent | 330212796756ca2752b2a70a83860e145b77487c (diff) | |
download | linux-73e39aaa8366694450cd6034050f542f965e277d.tar.xz |
NFSv4.1: Cleanup move session slot management to fs/nfs/nfs4session.c
NFSv4.1 session management is getting complex enough to deserve
a separate file.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4session.c')
-rw-r--r-- | fs/nfs/nfs4session.c | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c new file mode 100644 index 000000000000..701170293ceb --- /dev/null +++ b/fs/nfs/nfs4session.c @@ -0,0 +1,436 @@ +/* + * fs/nfs/nfs4session.c + * + * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com> + * + */ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/sunrpc/sched.h> +#include <linux/sunrpc/bc_xprt.h> +#include <linux/nfs.h> +#include <linux/nfs4.h> +#include <linux/nfs_fs.h> +#include <linux/module.h> + +#include "nfs4_fs.h" +#include "internal.h" +#include "nfs4session.h" +#include "callback.h" + +#define NFSDBG_FACILITY NFSDBG_STATE + +/* + * nfs4_shrink_slot_table - free retired slots from the slot table + */ +static void nfs4_shrink_slot_table(struct nfs4_slot_table *tbl, u32 newsize) +{ + struct nfs4_slot **p; + if (newsize >= tbl->max_slots) + return; + + p = &tbl->slots; + while (newsize--) + p = &(*p)->next; + while (*p) { + struct nfs4_slot *slot = *p; + + *p = slot->next; + kfree(slot); + tbl->max_slots--; + } +} + +/* + * nfs4_free_slot - free a slot and efficiently update slot table. + * + * freeing a slot is trivially done by clearing its respective bit + * in the bitmap. + * If the freed slotid equals highest_used_slotid we want to update it + * so that the server would be able to size down the slot table if needed, + * otherwise we know that the highest_used_slotid is still in use. + * When updating highest_used_slotid there may be "holes" in the bitmap + * so we need to scan down from highest_used_slotid to 0 looking for the now + * highest slotid in use. + * If none found, highest_used_slotid is set to NFS4_NO_SLOT. + * + * Must be called while holding tbl->slot_tbl_lock + */ +void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot) +{ + u32 slotid = slot->slot_nr; + + /* clear used bit in bitmap */ + __clear_bit(slotid, tbl->used_slots); + + /* update highest_used_slotid when it is freed */ + if (slotid == tbl->highest_used_slotid) { + u32 new_max = find_last_bit(tbl->used_slots, slotid); + if (new_max < slotid) + tbl->highest_used_slotid = new_max; + else { + tbl->highest_used_slotid = NFS4_NO_SLOT; + nfs4_session_drain_complete(tbl->session, tbl); + } + } + dprintk("%s: slotid %u highest_used_slotid %d\n", __func__, + slotid, tbl->highest_used_slotid); +} + +static struct nfs4_slot *nfs4_new_slot(struct nfs4_slot_table *tbl, + u32 slotid, u32 seq_init, gfp_t gfp_mask) +{ + struct nfs4_slot *slot; + + slot = kzalloc(sizeof(*slot), gfp_mask); + if (slot) { + slot->table = tbl; + slot->slot_nr = slotid; + slot->seq_nr = seq_init; + } + return slot; +} + +static struct nfs4_slot *nfs4_find_or_create_slot(struct nfs4_slot_table *tbl, + u32 slotid, u32 seq_init, gfp_t gfp_mask) +{ + struct nfs4_slot **p, *slot; + + p = &tbl->slots; + for (;;) { + if (*p == NULL) { + *p = nfs4_new_slot(tbl, tbl->max_slots, + seq_init, gfp_mask); + if (*p == NULL) + break; + tbl->max_slots++; + } + slot = *p; + if (slot->slot_nr == slotid) + return slot; + p = &slot->next; + } + return ERR_PTR(-ENOMEM); +} + +/* + * nfs4_alloc_slot - efficiently look for a free slot + * + * nfs4_alloc_slot looks for an unset bit in the used_slots bitmap. + * If found, we mark the slot as used, update the highest_used_slotid, + * and respectively set up the sequence operation args. + * + * Note: must be called with under the slot_tbl_lock. + */ +struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl) +{ + struct nfs4_slot *ret = ERR_PTR(-EBUSY); + u32 slotid; + + dprintk("--> %s used_slots=%04lx highest_used=%u max_slots=%u\n", + __func__, tbl->used_slots[0], tbl->highest_used_slotid, + tbl->max_slotid + 1); + slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1); + if (slotid > tbl->max_slotid) + goto out; + ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT); + if (IS_ERR(ret)) + goto out; + __set_bit(slotid, tbl->used_slots); + if (slotid > tbl->highest_used_slotid || + tbl->highest_used_slotid == NFS4_NO_SLOT) + tbl->highest_used_slotid = slotid; + ret->renewal_time = jiffies; + ret->generation = tbl->generation; + +out: + dprintk("<-- %s used_slots=%04lx highest_used=%d slotid=%d \n", + __func__, tbl->used_slots[0], tbl->highest_used_slotid, + !IS_ERR(ret) ? ret->slot_nr : -1); + return ret; +} + +static int nfs4_grow_slot_table(struct nfs4_slot_table *tbl, + u32 max_reqs, u32 ivalue) +{ + if (max_reqs <= tbl->max_slots) + return 0; + if (!IS_ERR(nfs4_find_or_create_slot(tbl, max_reqs - 1, ivalue, GFP_NOFS))) + return 0; + return -ENOMEM; +} + +static void nfs4_reset_slot_table(struct nfs4_slot_table *tbl, + u32 server_highest_slotid, + u32 ivalue) +{ + struct nfs4_slot **p; + + nfs4_shrink_slot_table(tbl, server_highest_slotid + 1); + p = &tbl->slots; + while (*p) { + (*p)->seq_nr = ivalue; + p = &(*p)->next; + } + tbl->highest_used_slotid = NFS4_NO_SLOT; + tbl->target_highest_slotid = server_highest_slotid; + tbl->server_highest_slotid = server_highest_slotid; + tbl->max_slotid = server_highest_slotid; +} + +/* + * (re)Initialise a slot table + */ +static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl, + u32 max_reqs, u32 ivalue) +{ + int ret; + + dprintk("--> %s: max_reqs=%u, tbl->max_slots %d\n", __func__, + max_reqs, tbl->max_slots); + + if (max_reqs > NFS4_MAX_SLOT_TABLE) + max_reqs = NFS4_MAX_SLOT_TABLE; + + ret = nfs4_grow_slot_table(tbl, max_reqs, ivalue); + if (ret) + goto out; + + spin_lock(&tbl->slot_tbl_lock); + nfs4_reset_slot_table(tbl, max_reqs - 1, ivalue); + spin_unlock(&tbl->slot_tbl_lock); + + dprintk("%s: tbl=%p slots=%p max_slots=%d\n", __func__, + tbl, tbl->slots, tbl->max_slots); +out: + dprintk("<-- %s: return %d\n", __func__, ret); + return ret; +} + +/* Destroy the slot table */ +static void nfs4_destroy_slot_tables(struct nfs4_session *session) +{ + nfs4_shrink_slot_table(&session->fc_slot_table, 0); + nfs4_shrink_slot_table(&session->bc_slot_table, 0); +} + +/* Update the client's idea of target_highest_slotid */ +static void nfs41_set_target_slotid_locked(struct nfs4_slot_table *tbl, + u32 target_highest_slotid) +{ + unsigned int max_slotid, i; + + if (tbl->target_highest_slotid == target_highest_slotid) + return; + tbl->target_highest_slotid = target_highest_slotid; + tbl->generation++; + + max_slotid = min(NFS4_MAX_SLOT_TABLE - 1, tbl->target_highest_slotid); + for (i = tbl->max_slotid + 1; i <= max_slotid; i++) + rpc_wake_up_next(&tbl->slot_tbl_waitq); + tbl->max_slotid = max_slotid; +} + +void nfs41_set_target_slotid(struct nfs4_slot_table *tbl, + u32 target_highest_slotid) +{ + spin_lock(&tbl->slot_tbl_lock); + nfs41_set_target_slotid_locked(tbl, target_highest_slotid); + spin_unlock(&tbl->slot_tbl_lock); +} + +static void nfs41_set_server_slotid_locked(struct nfs4_slot_table *tbl, + u32 highest_slotid) +{ + if (tbl->server_highest_slotid == highest_slotid) + return; + if (tbl->highest_used_slotid > highest_slotid) + return; + /* Deallocate slots */ + nfs4_shrink_slot_table(tbl, highest_slotid + 1); + tbl->server_highest_slotid = highest_slotid; +} + +void nfs41_update_target_slotid(struct nfs4_slot_table *tbl, + struct nfs4_slot *slot, + struct nfs4_sequence_res *res) +{ + spin_lock(&tbl->slot_tbl_lock); + if (tbl->generation != slot->generation) + goto out; + nfs41_set_server_slotid_locked(tbl, res->sr_highest_slotid); + nfs41_set_target_slotid_locked(tbl, res->sr_target_highest_slotid); +out: + spin_unlock(&tbl->slot_tbl_lock); +} + +/* + * Initialize or reset the forechannel and backchannel tables + */ +int nfs4_setup_session_slot_tables(struct nfs4_session *ses) +{ + struct nfs4_slot_table *tbl; + int status; + + dprintk("--> %s\n", __func__); + /* Fore channel */ + tbl = &ses->fc_slot_table; + tbl->session = ses; + status = nfs4_realloc_slot_table(tbl, ses->fc_attrs.max_reqs, 1); + if (status) /* -ENOMEM */ + return status; + /* Back channel */ + tbl = &ses->bc_slot_table; + tbl->session = ses; + status = nfs4_realloc_slot_table(tbl, ses->bc_attrs.max_reqs, 0); + if (status && tbl->slots == NULL) + /* Fore and back channel share a connection so get + * both slot tables or neither */ + nfs4_destroy_slot_tables(ses); + return status; +} + +struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp) +{ + struct nfs4_session *session; + struct nfs4_slot_table *tbl; + + session = kzalloc(sizeof(struct nfs4_session), GFP_NOFS); + if (!session) + return NULL; + + tbl = &session->fc_slot_table; + tbl->highest_used_slotid = NFS4_NO_SLOT; + spin_lock_init(&tbl->slot_tbl_lock); + rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, "ForeChannel Slot table"); + init_completion(&tbl->complete); + + tbl = &session->bc_slot_table; + tbl->highest_used_slotid = NFS4_NO_SLOT; + spin_lock_init(&tbl->slot_tbl_lock); + rpc_init_wait_queue(&tbl->slot_tbl_waitq, "BackChannel Slot table"); + init_completion(&tbl->complete); + + session->session_state = 1<<NFS4_SESSION_INITING; + + session->clp = clp; + return session; +} + +void nfs4_destroy_session(struct nfs4_session *session) +{ + struct rpc_xprt *xprt; + struct rpc_cred *cred; + + cred = nfs4_get_exchange_id_cred(session->clp); + nfs4_proc_destroy_session(session, cred); + if (cred) + put_rpccred(cred); + + rcu_read_lock(); + xprt = rcu_dereference(session->clp->cl_rpcclient->cl_xprt); + rcu_read_unlock(); + dprintk("%s Destroy backchannel for xprt %p\n", + __func__, xprt); + xprt_destroy_backchannel(xprt, NFS41_BC_MIN_CALLBACKS); + nfs4_destroy_slot_tables(session); + kfree(session); +} + +/* + * With sessions, the client is not marked ready until after a + * successful EXCHANGE_ID and CREATE_SESSION. + * + * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate + * other versions of NFS can be tried. + */ +static int nfs41_check_session_ready(struct nfs_client *clp) +{ + int ret; + + if (clp->cl_cons_state == NFS_CS_SESSION_INITING) { + ret = nfs4_client_recover_expired_lease(clp); + if (ret) + return ret; + } + if (clp->cl_cons_state < NFS_CS_READY) + return -EPROTONOSUPPORT; + smp_rmb(); + return 0; +} + +int nfs4_init_session(struct nfs_server *server) +{ + struct nfs_client *clp = server->nfs_client; + struct nfs4_session *session; + unsigned int target_max_rqst_sz = NFS_MAX_FILE_IO_SIZE; + unsigned int target_max_resp_sz = NFS_MAX_FILE_IO_SIZE; + + if (!nfs4_has_session(clp)) + return 0; + + if (server->rsize != 0) + target_max_resp_sz = server->rsize; + target_max_resp_sz += nfs41_maxread_overhead; + + if (server->wsize != 0) + target_max_rqst_sz = server->wsize; + target_max_rqst_sz += nfs41_maxwrite_overhead; + + session = clp->cl_session; + spin_lock(&clp->cl_lock); + if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) { + /* Initialise targets and channel attributes */ + session->fc_target_max_rqst_sz = target_max_rqst_sz; + session->fc_attrs.max_rqst_sz = target_max_rqst_sz; + session->fc_target_max_resp_sz = target_max_resp_sz; + session->fc_attrs.max_resp_sz = target_max_resp_sz; + } else { + /* Just adjust the targets */ + if (target_max_rqst_sz > session->fc_target_max_rqst_sz) { + session->fc_target_max_rqst_sz = target_max_rqst_sz; + set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state); + } + if (target_max_resp_sz > session->fc_target_max_resp_sz) { + session->fc_target_max_resp_sz = target_max_resp_sz; + set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state); + } + } + spin_unlock(&clp->cl_lock); + + if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) + nfs4_schedule_lease_recovery(clp); + + return nfs41_check_session_ready(clp); +} + +int nfs4_init_ds_session(struct nfs_client *clp, unsigned long lease_time) +{ + struct nfs4_session *session = clp->cl_session; + int ret; + + spin_lock(&clp->cl_lock); + if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) { + /* + * Do not set NFS_CS_CHECK_LEASE_TIME instead set the + * DS lease to be equal to the MDS lease. + */ + clp->cl_lease_time = lease_time; + clp->cl_last_renewal = jiffies; + } + spin_unlock(&clp->cl_lock); + + ret = nfs41_check_session_ready(clp); + if (ret) + return ret; + /* Test for the DS role */ + if (!is_ds_client(clp)) + return -ENODEV; + return 0; +} +EXPORT_SYMBOL_GPL(nfs4_init_ds_session); + + |