NFSv4.1: Shrink struct nfs4_sequence_res by moving the session pointer

Move the session pointer into the slot table, then have struct nfs4_slot
point to that slot table.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

6 files changed, 33 insertions, 16 deletions

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 36880b9aa91..42c58691fb4 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -258,7 +258,8 @@ extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
 extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
                                   bool sync);
 
-extern struct nfs4_slot *nfs4_alloc_slots(u32 max_slots, gfp_t gfp_flags);
+extern struct nfs4_slot *nfs4_alloc_slots(struct nfs4_slot_table *table,
+                u32 max_slots, gfp_t gfp_flags);
 
 static inline bool
 is_ds_only_client(struct nfs_client *clp)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 14b39742b6e..5b61c4a8319 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -467,25 +467,28 @@ void nfs4_check_drain_bc_complete(struct nfs4_session *ses)
 
 static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
 {
+        struct nfs4_session *session;
         struct nfs4_slot_table *tbl;
 
-        tbl = &res->sr_session->fc_slot_table;
         if (!res->sr_slot) {
                 /* just wake up the next guy waiting since
                  * we may have not consumed a slot after all */
                 dprintk("%s: No slot\n", __func__);
                 return;
         }
+        tbl = res->sr_slot->table;
+        session = tbl->session;
 
         spin_lock(&tbl->slot_tbl_lock);
         nfs4_free_slot(tbl, res->sr_slot - tbl->slots);
-        nfs4_check_drain_fc_complete(res->sr_session);
+        nfs4_check_drain_fc_complete(session);
         spin_unlock(&tbl->slot_tbl_lock);
         res->sr_slot = NULL;
 }
 
 static int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *res)
 {
+        struct nfs4_session *session;
         struct nfs4_slot *slot;
         unsigned long timestamp;
         struct nfs_client *clp;
@@ -504,6 +507,7 @@ static int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *
                 goto out;
 
         slot = res->sr_slot;
+        session = slot->table->session;
 
         /* Check the SEQUENCE operation status */
         switch (res->sr_status) {
@@ -511,7 +515,7 @@ static int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *
                 /* Update the slot's sequence and clientid lease timer */
                 ++slot->seq_nr;
                 timestamp = slot->renewal_time;
-                clp = res->sr_session->clp;
+                clp = session->clp;
                 do_renew_lease(clp, timestamp);
                 /* Check sequence flags */
                 if (res->sr_status_flags != 0)
@@ -524,7 +528,7 @@ static int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *
                  */
                 dprintk("%s: slot=%td seq=%d: Operation in progress\n",
                         __func__,
-                        slot - res->sr_session->fc_slot_table.slots,
+                        slot - session->fc_slot_table.slots,
                         slot->seq_nr);
                 goto out_retry;
         default:
@@ -546,7 +550,7 @@ out_retry:
 static int nfs4_sequence_done(struct rpc_task *task,
                                struct nfs4_sequence_res *res)
 {
-        if (res->sr_session == NULL)
+        if (res->sr_slot == NULL)
                 return 1;
         return nfs41_sequence_done(task, res);
 }
@@ -591,7 +595,6 @@ static void nfs41_init_sequence(struct nfs4_sequence_args *args,
         args->sa_cache_this = 0;
         if (cache_reply)
                 args->sa_cache_this = 1;
-        res->sr_session = NULL;
         res->sr_slot = NULL;
 }
 
@@ -646,7 +649,6 @@ int nfs41_setup_sequence(struct nfs4_session *session,
 
         dprintk("<-- %s slotid=%d seqid=%d\n", __func__, slotid, slot->seq_nr);
 
-        res->sr_session = session;
         res->sr_slot = slot;
         res->sr_status_flags = 0;
         /*
@@ -5659,9 +5661,18 @@ int nfs4_proc_get_lease_time(struct nfs_client *clp, struct nfs_fsinfo *fsinfo)
         return status;
 }
 
-struct nfs4_slot *nfs4_alloc_slots(u32 max_slots, gfp_t gfp_flags)
+struct nfs4_slot *nfs4_alloc_slots(struct nfs4_slot_table *table,
+                u32 max_slots, gfp_t gfp_flags)
 {
-        return kmalloc_array(max_slots, sizeof(struct nfs4_slot), gfp_flags);
+        struct nfs4_slot *tbl;
+        u32 i;
+
+        tbl = kmalloc_array(max_slots, sizeof(*tbl), gfp_flags);
+        if (tbl != NULL) {
+                for (i = 0; i < max_slots; i++)
+                        tbl[i].table = table;
+        }
+        return tbl;
 }
 
 static void nfs4_add_and_init_slots(struct nfs4_slot_table *tbl,
@@ -5699,7 +5710,7 @@ static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl, u32 max_reqs,
 
         /* Does the newly negotiated max_reqs match the existing slot table? */
         if (max_reqs != tbl->max_slots) {
-                new = nfs4_alloc_slots(max_reqs, GFP_NOFS);
+                new = nfs4_alloc_slots(tbl, max_reqs, GFP_NOFS);
                 if (!new)
                         goto out;
         }
@@ -5738,11 +5749,13 @@ static int nfs4_setup_session_slot_tables(struct nfs4_session *ses)
         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
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 96fcbb97fd6..9495789c425 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -2033,7 +2033,7 @@ static int nfs4_recall_slot(struct nfs_client *clp)
                 return 0;
         nfs4_begin_drain_session(clp);
         fc_tbl = &clp->cl_session->fc_slot_table;
-        new = nfs4_alloc_slots(fc_tbl->target_max_slots, GFP_NOFS);
+        new = nfs4_alloc_slots(fc_tbl, fc_tbl->target_max_slots, GFP_NOFS);
         if (!new)
                 return -ENOMEM;
 
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 672d9b0ef2c..4126f054610 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5507,12 +5507,13 @@ static int decode_sequence(struct xdr_stream *xdr,
                            struct rpc_rqst *rqstp)
 {
 #if defined(CONFIG_NFS_V4_1)
+        struct nfs4_session *session;
         struct nfs4_sessionid id;
         u32 dummy;
         int status;
         __be32 *p;
 
-        if (!res->sr_session)
+        if (res->sr_slot == NULL)
                 return 0;
 
         status = decode_op_hdr(xdr, OP_SEQUENCE);
@@ -5526,8 +5527,9 @@ static int decode_sequence(struct xdr_stream *xdr,
          * sequence number, the server is looney tunes.
          */
         status = -EREMOTEIO;
+        session = res->sr_slot->table->session;
 
-        if (memcmp(id.data, res->sr_session->sess_id.data,
+        if (memcmp(id.data, session->sess_id.data,
                    NFS4_MAX_SESSIONID_LEN)) {
                 dprintk("%s Invalid session id\n", __func__);
                 goto out_err;
@@ -5545,7 +5547,7 @@ static int decode_sequence(struct xdr_stream *xdr,
         }
         /* slot id */
         dummy = be32_to_cpup(p++);
-        if (dummy != res->sr_slot - res->sr_session->fc_slot_table.slots) {
+        if (dummy != res->sr_slot - session->fc_slot_table.slots) {
                 dprintk("%s Invalid slot id\n", __func__);
                 goto out_err;
         }
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 97c8f919188..b0412873d29 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -209,6 +209,7 @@ struct nfs_server {
 /* Sessions */
 #define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
 struct nfs4_slot_table {
+        struct nfs4_session *session;           /* Parent session */
         struct nfs4_slot *slots;                /* seqid per slot */
         unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
         spinlock_t      slot_tbl_lock;
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 9cb1c63a70c..0fd88ab0e81 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -187,6 +187,7 @@ struct nfs4_channel_attrs {
 
 /* nfs41 sessions slot seqid */
 struct nfs4_slot {
+        struct nfs4_slot_table  *table;
         unsigned long           renewal_time;
         u32                     seq_nr;
 };
@@ -198,7 +199,6 @@ struct nfs4_sequence_args {
 };
 
 struct nfs4_sequence_res {
-        struct nfs4_session     *sr_session;
         struct nfs4_slot        *sr_slot;       /* slot used to send request */
         int                     sr_status;      /* sequence operation status */
         u32                     sr_status_flags;