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authorTrond Myklebust <Trond.Myklebust@netapp.com>2012-11-26 12:49:34 -0500
committerTrond Myklebust <Trond.Myklebust@netapp.com>2012-12-06 00:30:45 +0100
commit73e39aaa8366694450cd6034050f542f965e277d (patch)
treedf731a81afdd826a401f611dd85c9cf08a9cd0c1 /fs/nfs
parent330212796756ca2752b2a70a83860e145b77487c (diff)
downloadlinux-73e39aaa8366694450cd6034050f542f965e277d.tar.bz2
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')
-rw-r--r--fs/nfs/Makefile2
-rw-r--r--fs/nfs/callback_proc.c1
-rw-r--r--fs/nfs/internal.h2
-rw-r--r--fs/nfs/nfs4_fs.h11
-rw-r--r--fs/nfs/nfs4client.c1
-rw-r--r--fs/nfs/nfs4filelayoutdev.c1
-rw-r--r--fs/nfs/nfs4proc.c415
-rw-r--r--fs/nfs/nfs4session.c436
-rw-r--r--fs/nfs/nfs4session.h35
9 files changed, 477 insertions, 427 deletions
diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index b7db60897f91..cce2c057bd2d 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -24,7 +24,7 @@ nfsv4-y := nfs4proc.o nfs4xdr.o nfs4state.o nfs4renewd.o nfs4super.o nfs4file.o
delegation.o idmap.o callback.o callback_xdr.o callback_proc.o \
nfs4namespace.o nfs4getroot.o nfs4client.o
nfsv4-$(CONFIG_SYSCTL) += nfs4sysctl.o
-nfsv4-$(CONFIG_NFS_V4_1) += pnfs.o pnfs_dev.o
+nfsv4-$(CONFIG_NFS_V4_1) += nfs4session.o pnfs.o pnfs_dev.o
obj-$(CONFIG_PNFS_FILE_LAYOUT) += nfs_layout_nfsv41_files.o
nfs_layout_nfsv41_files-y := nfs4filelayout.o nfs4filelayoutdev.o
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index f99faad78c72..c89b26bc9759 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -14,6 +14,7 @@
#include "delegation.h"
#include "internal.h"
#include "pnfs.h"
+#include "nfs4session.h"
#ifdef NFS_DEBUG
#define NFSDBG_FACILITY NFSDBG_CALLBACK
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 05521cadac2e..8965a998b306 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -276,8 +276,6 @@ extern const u32 nfs41_maxwrite_overhead;
extern struct rpc_procinfo nfs4_procedures[];
#endif
-extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
-
/* proc.c */
void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 2f6a9f9d9299..cd3e3096b60a 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -249,19 +249,13 @@ extern int nfs4_setup_sequence(const struct nfs_server *server,
extern int nfs41_setup_sequence(struct nfs4_session *session,
struct nfs4_sequence_args *args, struct nfs4_sequence_res *res,
struct rpc_task *task);
-extern void nfs4_destroy_session(struct nfs4_session *session);
-extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
extern int nfs4_proc_create_session(struct nfs_client *, struct rpc_cred *);
extern int nfs4_proc_destroy_session(struct nfs4_session *, struct rpc_cred *);
-extern int nfs4_init_session(struct nfs_server *server);
extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
struct nfs_fsinfo *fsinfo);
extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
bool sync);
-extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
- u32 target_highest_slotid);
-
static inline bool
is_ds_only_client(struct nfs_client *clp)
{
@@ -287,11 +281,6 @@ static inline int nfs4_setup_sequence(const struct nfs_server *server,
return 0;
}
-static inline int nfs4_init_session(struct nfs_server *server)
-{
- return 0;
-}
-
static inline bool
is_ds_only_client(struct nfs_client *clp)
{
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 72717e67b34e..acc347268124 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -12,6 +12,7 @@
#include "internal.h"
#include "callback.h"
#include "delegation.h"
+#include "nfs4session.h"
#include "pnfs.h"
#include "netns.h"
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index 93e2530d7098..b720064bcd7f 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -33,6 +33,7 @@
#include <linux/module.h>
#include "internal.h"
+#include "nfs4session.h"
#include "nfs4filelayout.h"
#define NFSDBG_FACILITY NFSDBG_PNFS_LD
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d75e2a2576eb..a0c35ab12a6b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -52,7 +52,6 @@
#include <linux/mount.h>
#include <linux/module.h>
#include <linux/nfs_idmap.h>
-#include <linux/sunrpc/bc_xprt.h>
#include <linux/xattr.h>
#include <linux/utsname.h>
#include <linux/freezer.h>
@@ -64,6 +63,8 @@
#include "callback.h"
#include "pnfs.h"
#include "netns.h"
+#include "nfs4session.h"
+
#define NFSDBG_FACILITY NFSDBG_PROC
@@ -378,64 +379,6 @@ static void renew_lease(const struct nfs_server *server, unsigned long timestamp
#if defined(CONFIG_NFS_V4_1)
-/*
- * 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
- */
-static 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);
-}
-
bool nfs4_set_task_privileged(struct rpc_task *task, void *dummy)
{
rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
@@ -465,56 +408,6 @@ static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
res->sr_slot = NULL;
}
-/* 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;
-}
-
-static 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);
-}
-
static int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *res)
{
struct nfs4_session *session;
@@ -585,79 +478,6 @@ static int nfs4_sequence_done(struct rpc_task *task,
return nfs41_sequence_done(task, res);
}
-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.
- */
-static 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 void nfs41_init_sequence(struct nfs4_sequence_args *args,
struct nfs4_sequence_res *res, int cache_reply)
{
@@ -5716,143 +5536,6 @@ int nfs4_proc_get_lease_time(struct nfs_client *clp, struct nfs_fsinfo *fsinfo)
return status;
}
-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);
-}
-
-/*
- * Initialize or reset the forechannel and backchannel tables
- */
-static 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);
-}
-
/*
* Initialize the values to be used by the client in CREATE_SESSION
* If nfs4_init_session set the fore channel request and response sizes,
@@ -6047,100 +5730,6 @@ int nfs4_proc_destroy_session(struct nfs4_session *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);
-
-
-/*
* Renew the cl_session lease.
*/
struct nfs4_sequence_data {
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);
+
+
diff --git a/fs/nfs/nfs4session.h b/fs/nfs/nfs4session.h
new file mode 100644
index 000000000000..cb47b1eb0886
--- /dev/null
+++ b/fs/nfs/nfs4session.h
@@ -0,0 +1,35 @@
+/*
+ * fs/nfs/nfs4session.h
+ *
+ * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
+ *
+ */
+#ifndef __LINUX_FS_NFS_NFS4SESSION_H
+#define __LINUX_FS_NFS_NFS4SESSION_H
+
+#if defined(CONFIG_NFS_V4_1)
+extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
+extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
+
+extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
+ u32 target_highest_slotid);
+extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
+ struct nfs4_slot *slot,
+ struct nfs4_sequence_res *res);
+
+extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
+
+extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
+extern void nfs4_destroy_session(struct nfs4_session *session);
+extern int nfs4_init_session(struct nfs_server *server);
+extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
+
+#else /* defined(CONFIG_NFS_V4_1) */
+
+static inline int nfs4_init_session(struct nfs_server *server)
+{
+ return 0;
+}
+
+#endif /* defined(CONFIG_NFS_V4_1) */
+#endif /* __LINUX_FS_NFS_NFS4SESSION_H */