NFSv4.1: keep seq_res.sr_slot as pointer rather than an index
Having to explicitly initialize sr_slotid to NFS4_MAX_SLOT_TABLE
resulted in numerous bugs. Keeping the current slot as a pointer
to the slot table is more straight forward and robust as it's
implicitly set up to NULL wherever the seq_res member is initialized
to zeroes.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 72aa706..aee1bcc 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -334,10 +334,12 @@
* Must be called while holding tbl->slot_tbl_lock
*/
static void
-nfs4_free_slot(struct nfs4_slot_table *tbl, u8 free_slotid)
+nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *free_slot)
{
+ int free_slotid = free_slot - tbl->slots;
int slotid = free_slotid;
+ BUG_ON(slotid < 0 || slotid >= NFS4_MAX_SLOT_TABLE);
/* clear used bit in bitmap */
__clear_bit(slotid, tbl->used_slots);
@@ -379,7 +381,7 @@
struct nfs4_slot_table *tbl;
tbl = &res->sr_session->fc_slot_table;
- if (res->sr_slotid == NFS4_MAX_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__);
@@ -387,17 +389,15 @@
}
spin_lock(&tbl->slot_tbl_lock);
- nfs4_free_slot(tbl, res->sr_slotid);
+ nfs4_free_slot(tbl, res->sr_slot);
nfs41_check_drain_session_complete(res->sr_session);
spin_unlock(&tbl->slot_tbl_lock);
- res->sr_slotid = NFS4_MAX_SLOT_TABLE;
+ res->sr_slot = NULL;
}
static int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *res)
{
unsigned long timestamp;
- struct nfs4_slot_table *tbl;
- struct nfs4_slot *slot;
struct nfs_client *clp;
/*
@@ -410,17 +410,14 @@
res->sr_status = NFS_OK;
/* -ERESTARTSYS can result in skipping nfs41_sequence_setup */
- if (res->sr_slotid == NFS4_MAX_SLOT_TABLE)
+ if (!res->sr_slot)
goto out;
- tbl = &res->sr_session->fc_slot_table;
- slot = tbl->slots + res->sr_slotid;
-
/* Check the SEQUENCE operation status */
switch (res->sr_status) {
case 0:
/* Update the slot's sequence and clientid lease timer */
- ++slot->seq_nr;
+ ++res->sr_slot->seq_nr;
timestamp = res->sr_renewal_time;
clp = res->sr_session->clp;
do_renew_lease(clp, timestamp);
@@ -433,12 +430,14 @@
* returned NFS4ERR_DELAY as per Section 2.10.6.2
* of RFC5661.
*/
- dprintk("%s: slot=%d seq=%d: Operation in progress\n",
- __func__, res->sr_slotid, slot->seq_nr);
+ dprintk("%s: slot=%ld seq=%d: Operation in progress\n",
+ __func__,
+ res->sr_slot - res->sr_session->fc_slot_table.slots,
+ res->sr_slot->seq_nr);
goto out_retry;
default:
/* Just update the slot sequence no. */
- ++slot->seq_nr;
+ ++res->sr_slot->seq_nr;
}
out:
/* The session may be reset by one of the error handlers. */
@@ -505,10 +504,9 @@
dprintk("--> %s\n", __func__);
/* slot already allocated? */
- if (res->sr_slotid != NFS4_MAX_SLOT_TABLE)
+ if (res->sr_slot != NULL)
return 0;
- res->sr_slotid = NFS4_MAX_SLOT_TABLE;
tbl = &session->fc_slot_table;
spin_lock(&tbl->slot_tbl_lock);
@@ -550,7 +548,7 @@
dprintk("<-- %s slotid=%d seqid=%d\n", __func__, slotid, slot->seq_nr);
res->sr_session = session;
- res->sr_slotid = slotid;
+ res->sr_slot = slot;
res->sr_renewal_time = jiffies;
res->sr_status_flags = 0;
/*
@@ -576,8 +574,9 @@
goto out;
}
- dprintk("--> %s clp %p session %p sr_slotid %d\n",
- __func__, session->clp, session, res->sr_slotid);
+ dprintk("--> %s clp %p session %p sr_slot %ld\n",
+ __func__, session->clp, session, res->sr_slot ?
+ res->sr_slot - session->fc_slot_table.slots : -1);
ret = nfs41_setup_sequence(session, args, res, cache_reply,
task);
@@ -650,7 +649,7 @@
.callback_data = &data
};
- res->sr_slotid = NFS4_MAX_SLOT_TABLE;
+ res->sr_slot = NULL;
if (privileged)
task_setup.callback_ops = &nfs41_call_priv_sync_ops;
task = rpc_run_task(&task_setup);
@@ -735,7 +734,6 @@
p->o_res.server = p->o_arg.server;
nfs_fattr_init(&p->f_attr);
nfs_fattr_init(&p->dir_attr);
- p->o_res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
}
static struct nfs4_opendata *nfs4_opendata_alloc(struct path *path,
@@ -1975,7 +1973,6 @@
calldata->res.fattr = &calldata->fattr;
calldata->res.seqid = calldata->arg.seqid;
calldata->res.server = server;
- calldata->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
path_get(path);
calldata->path = *path;
@@ -2550,7 +2547,7 @@
args->bitmask = server->cache_consistency_bitmask;
res->server = server;
- res->seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
+ res->seq_res.sr_slot = NULL;
msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVE];
}
@@ -2576,7 +2573,6 @@
msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RENAME];
arg->bitmask = server->attr_bitmask;
res->server = server;
- res->seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
}
static int nfs4_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
@@ -3646,7 +3642,6 @@
memcpy(&data->stateid, stateid, sizeof(data->stateid));
data->res.fattr = &data->fattr;
data->res.server = server;
- data->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
nfs_fattr_init(data->res.fattr);
data->timestamp = jiffies;
data->rpc_status = 0;
@@ -3799,7 +3794,6 @@
p->arg.fl = &p->fl;
p->arg.seqid = seqid;
p->res.seqid = seqid;
- p->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
p->arg.stateid = &lsp->ls_stateid;
p->lsp = lsp;
atomic_inc(&lsp->ls_count);
@@ -3979,7 +3973,6 @@
p->arg.lock_owner.clientid = server->nfs_client->cl_clientid;
p->arg.lock_owner.id = lsp->ls_id.id;
p->res.lock_seqid = p->arg.lock_seqid;
- p->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
p->lsp = lsp;
p->server = server;
atomic_inc(&lsp->ls_count);
@@ -4612,7 +4605,6 @@
};
int status;
- res.lr_seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
dprintk("--> %s\n", __func__);
task = rpc_run_task(&task_setup);
@@ -5105,12 +5097,11 @@
if (!atomic_inc_not_zero(&clp->cl_count))
return ERR_PTR(-EIO);
- calldata = kmalloc(sizeof(*calldata), GFP_NOFS);
+ calldata = kzalloc(sizeof(*calldata), GFP_NOFS);
if (calldata == NULL) {
nfs_put_client(clp);
return ERR_PTR(-ENOMEM);
}
- calldata->res.sr_slotid = NFS4_MAX_SLOT_TABLE;
msg.rpc_argp = &calldata->args;
msg.rpc_resp = &calldata->res;
calldata->clp = clp;
@@ -5242,7 +5233,6 @@
goto out;
calldata->clp = clp;
calldata->arg.one_fs = 0;
- calldata->res.seq_res.sr_slotid = NFS4_MAX_SLOT_TABLE;
msg.rpc_argp = &calldata->arg;
msg.rpc_resp = &calldata->res;