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nfsd: move the confirmed and unconfirmed hlists to a rbtree
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The current code requires that we md5 hash the name in order to store
the client in the confirmed and unconfirmed trees. Change it instead
to store the clients in a pair of rbtrees, and simply compare the
cl_names directly instead of hashing them. This also necessitates that
we add a new flag to the clp->cl_flags field to indicate which tree
the client is currently in.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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Jeff Layton authored and J. Bruce Fields committed Nov 12, 2012
1 parent 0ce0c2b commit ac55fdc
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Showing 2 changed files with 95 additions and 52 deletions.
144 changes: 93 additions & 51 deletions fs/nfsd/nfs4state.c
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Original file line number Diff line number Diff line change
Expand Up @@ -412,24 +412,26 @@ static unsigned int clientstr_hashval(const char *name)
* reclaim_str_hashtbl[] holds known client info from previous reset/reboot
* used in reboot/reset lease grace period processing
*
* conf_id_hashtbl[], and conf_str_hashtbl[] hold confirmed
* conf_id_hashtbl[], and conf_name_tree hold confirmed
* setclientid_confirmed info.
*
* unconf_str_hastbl[] and unconf_id_hashtbl[] hold unconfirmed
* unconf_id_hashtbl[] and unconf_name_tree hold unconfirmed
* setclientid info.
*
* client_lru holds client queue ordered by nfs4_client.cl_time
* for lease renewal.
*
* close_lru holds (open) stateowner queue ordered by nfs4_stateowner.so_time
* for last close replay.
*
* All of the above fields are protected by the client_mutex.
*/
static struct list_head reclaim_str_hashtbl[CLIENT_HASH_SIZE];
static int reclaim_str_hashtbl_size = 0;
static struct list_head conf_id_hashtbl[CLIENT_HASH_SIZE];
static struct list_head conf_str_hashtbl[CLIENT_HASH_SIZE];
static struct list_head unconf_str_hashtbl[CLIENT_HASH_SIZE];
static struct list_head unconf_id_hashtbl[CLIENT_HASH_SIZE];
static struct rb_root conf_name_tree;
static struct rb_root unconf_name_tree;
static struct list_head client_lru;
static struct list_head close_lru;

Expand Down Expand Up @@ -1144,7 +1146,10 @@ destroy_client(struct nfs4_client *clp)
if (clp->cl_cb_conn.cb_xprt)
svc_xprt_put(clp->cl_cb_conn.cb_xprt);
list_del(&clp->cl_idhash);
list_del(&clp->cl_strhash);
if (test_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags))
rb_erase(&clp->cl_namenode, &conf_name_tree);
else
rb_erase(&clp->cl_namenode, &unconf_name_tree);
spin_lock(&client_lock);
unhash_client_locked(clp);
if (atomic_read(&clp->cl_refcount) == 0)
Expand Down Expand Up @@ -1187,6 +1192,17 @@ static int copy_cred(struct svc_cred *target, struct svc_cred *source)
return 0;
}

static long long
compare_blob(const struct xdr_netobj *o1, const struct xdr_netobj *o2)
{
long long res;

res = o1->len - o2->len;
if (res)
return res;
return (long long)memcmp(o1->data, o2->data, o1->len);
}

static int same_name(const char *n1, const char *n2)
{
return 0 == memcmp(n1, n2, HEXDIR_LEN);
Expand Down Expand Up @@ -1307,7 +1323,6 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
atomic_set(&clp->cl_refcount, 0);
clp->cl_cb_state = NFSD4_CB_UNKNOWN;
INIT_LIST_HEAD(&clp->cl_idhash);
INIT_LIST_HEAD(&clp->cl_strhash);
INIT_LIST_HEAD(&clp->cl_openowners);
INIT_LIST_HEAD(&clp->cl_delegations);
INIT_LIST_HEAD(&clp->cl_lru);
Expand All @@ -1325,11 +1340,52 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
}

static void
add_to_unconfirmed(struct nfs4_client *clp, unsigned int strhashval)
add_clp_to_name_tree(struct nfs4_client *new_clp, struct rb_root *root)
{
struct rb_node **new = &(root->rb_node), *parent = NULL;
struct nfs4_client *clp;

while (*new) {
clp = rb_entry(*new, struct nfs4_client, cl_namenode);
parent = *new;

if (compare_blob(&clp->cl_name, &new_clp->cl_name) > 0)
new = &((*new)->rb_left);
else
new = &((*new)->rb_right);
}

rb_link_node(&new_clp->cl_namenode, parent, new);
rb_insert_color(&new_clp->cl_namenode, root);
}

static struct nfs4_client *
find_clp_in_name_tree(struct xdr_netobj *name, struct rb_root *root)
{
long long cmp;
struct rb_node *node = root->rb_node;
struct nfs4_client *clp;

while (node) {
clp = rb_entry(node, struct nfs4_client, cl_namenode);
cmp = compare_blob(&clp->cl_name, name);
if (cmp > 0)
node = node->rb_left;
else if (cmp < 0)
node = node->rb_right;
else
return clp;
}
return NULL;
}

static void
add_to_unconfirmed(struct nfs4_client *clp)
{
unsigned int idhashval;

list_add(&clp->cl_strhash, &unconf_str_hashtbl[strhashval]);
clear_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
add_clp_to_name_tree(clp, &unconf_name_tree);
idhashval = clientid_hashval(clp->cl_clientid.cl_id);
list_add(&clp->cl_idhash, &unconf_id_hashtbl[idhashval]);
renew_client(clp);
Expand All @@ -1339,12 +1395,12 @@ static void
move_to_confirmed(struct nfs4_client *clp)
{
unsigned int idhashval = clientid_hashval(clp->cl_clientid.cl_id);
unsigned int strhashval;

dprintk("NFSD: move_to_confirm nfs4_client %p\n", clp);
list_move(&clp->cl_idhash, &conf_id_hashtbl[idhashval]);
strhashval = clientstr_hashval(clp->cl_recdir);
list_move(&clp->cl_strhash, &conf_str_hashtbl[strhashval]);
rb_erase(&clp->cl_namenode, &unconf_name_tree);
add_clp_to_name_tree(clp, &conf_name_tree);
set_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
renew_client(clp);
}

Expand Down Expand Up @@ -1387,27 +1443,15 @@ static bool clp_used_exchangeid(struct nfs4_client *clp)
}

static struct nfs4_client *
find_confirmed_client_by_str(const char *dname, unsigned int hashval)
find_confirmed_client_by_name(struct xdr_netobj *name)
{
struct nfs4_client *clp;

list_for_each_entry(clp, &conf_str_hashtbl[hashval], cl_strhash) {
if (same_name(clp->cl_recdir, dname))
return clp;
}
return NULL;
return find_clp_in_name_tree(name, &conf_name_tree);
}

static struct nfs4_client *
find_unconfirmed_client_by_str(const char *dname, unsigned int hashval)
find_unconfirmed_client_by_name(struct xdr_netobj *name)
{
struct nfs4_client *clp;

list_for_each_entry(clp, &unconf_str_hashtbl[hashval], cl_strhash) {
if (same_name(clp->cl_recdir, dname))
return clp;
}
return NULL;
return find_clp_in_name_tree(name, &unconf_name_tree);
}

static void
Expand Down Expand Up @@ -1572,7 +1616,6 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
{
struct nfs4_client *unconf, *conf, *new;
__be32 status;
unsigned int strhashval;
char dname[HEXDIR_LEN];
char addr_str[INET6_ADDRSTRLEN];
nfs4_verifier verf = exid->verifier;
Expand Down Expand Up @@ -1605,11 +1648,9 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
if (status)
return status;

strhashval = clientstr_hashval(dname);

/* Cases below refer to rfc 5661 section 18.35.4: */
nfs4_lock_state();
conf = find_confirmed_client_by_str(dname, strhashval);
conf = find_confirmed_client_by_name(&exid->clname);
if (conf) {
bool creds_match = same_creds(&conf->cl_cred, &rqstp->rq_cred);
bool verfs_match = same_verf(&verf, &conf->cl_verifier);
Expand Down Expand Up @@ -1654,7 +1695,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
goto out;
}

unconf = find_unconfirmed_client_by_str(dname, strhashval);
unconf = find_unconfirmed_client_by_name(&exid->clname);
if (unconf) /* case 4, possible retry or client restart */
expire_client(unconf);

Expand All @@ -1668,7 +1709,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
new->cl_minorversion = 1;

gen_clid(new);
add_to_unconfirmed(new, strhashval);
add_to_unconfirmed(new);
out_copy:
exid->clientid.cl_boot = new->cl_clientid.cl_boot;
exid->clientid.cl_id = new->cl_clientid.cl_id;
Expand Down Expand Up @@ -1789,7 +1830,6 @@ nfsd4_create_session(struct svc_rqst *rqstp,
goto out_free_conn;
}
} else if (unconf) {
unsigned int hash;
struct nfs4_client *old;
if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) ||
!rpc_cmp_addr(sa, (struct sockaddr *) &unconf->cl_addr)) {
Expand All @@ -1803,8 +1843,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
status = nfserr_seq_misordered;
goto out_free_conn;
}
hash = clientstr_hashval(unconf->cl_recdir);
old = find_confirmed_client_by_str(unconf->cl_recdir, hash);
old = find_confirmed_client_by_name(&unconf->cl_name);
if (old)
expire_client(old);
move_to_confirmed(unconf);
Expand Down Expand Up @@ -2195,7 +2234,6 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
{
struct xdr_netobj clname = setclid->se_name;
nfs4_verifier clverifier = setclid->se_verf;
unsigned int strhashval;
struct nfs4_client *conf, *unconf, *new;
__be32 status;
char dname[HEXDIR_LEN];
Expand All @@ -2204,11 +2242,9 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
if (status)
return status;

strhashval = clientstr_hashval(dname);

/* Cases below refer to rfc 3530 section 14.2.33: */
nfs4_lock_state();
conf = find_confirmed_client_by_str(dname, strhashval);
conf = find_confirmed_client_by_name(&clname);
if (conf) {
/* case 0: */
status = nfserr_clid_inuse;
Expand All @@ -2223,7 +2259,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
goto out;
}
}
unconf = find_unconfirmed_client_by_str(dname, strhashval);
unconf = find_unconfirmed_client_by_name(&clname);
if (unconf)
expire_client(unconf);
status = nfserr_jukebox;
Expand All @@ -2237,7 +2273,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
gen_clid(new);
new->cl_minorversion = 0;
gen_callback(new, setclid, rqstp);
add_to_unconfirmed(new, strhashval);
add_to_unconfirmed(new);
setclid->se_clientid.cl_boot = new->cl_clientid.cl_boot;
setclid->se_clientid.cl_id = new->cl_clientid.cl_id;
memcpy(setclid->se_confirm.data, new->cl_confirm.data, sizeof(setclid->se_confirm.data));
Expand Down Expand Up @@ -2290,9 +2326,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
nfsd4_probe_callback(conf);
expire_client(unconf);
} else { /* case 3: normal case; new or rebooted client */
unsigned int hash = clientstr_hashval(unconf->cl_recdir);

conf = find_confirmed_client_by_str(unconf->cl_recdir, hash);
conf = find_confirmed_client_by_name(&unconf->cl_name);
if (conf)
expire_client(conf);
move_to_confirmed(unconf);
Expand Down Expand Up @@ -4706,11 +4740,11 @@ nfs4_state_init(void)

for (i = 0; i < CLIENT_HASH_SIZE; i++) {
INIT_LIST_HEAD(&conf_id_hashtbl[i]);
INIT_LIST_HEAD(&conf_str_hashtbl[i]);
INIT_LIST_HEAD(&unconf_str_hashtbl[i]);
INIT_LIST_HEAD(&unconf_id_hashtbl[i]);
INIT_LIST_HEAD(&reclaim_str_hashtbl[i]);
}
conf_name_tree = RB_ROOT;
unconf_name_tree = RB_ROOT;
for (i = 0; i < SESSION_HASH_SIZE; i++)
INIT_LIST_HEAD(&sessionid_hashtbl[i]);
for (i = 0; i < FILE_HASH_SIZE; i++) {
Expand Down Expand Up @@ -4795,24 +4829,32 @@ nfs4_state_start(void)
return ret;
}

/* should be called with the state lock held */
static void
__nfs4_state_shutdown(void)
{
int i;
struct nfs4_client *clp = NULL;
struct nfs4_delegation *dp = NULL;
struct list_head *pos, *next, reaplist;
struct rb_node *node, *tmp;

for (i = 0; i < CLIENT_HASH_SIZE; i++) {
while (!list_empty(&conf_id_hashtbl[i])) {
clp = list_entry(conf_id_hashtbl[i].next, struct nfs4_client, cl_idhash);
destroy_client(clp);
}
while (!list_empty(&unconf_str_hashtbl[i])) {
clp = list_entry(unconf_str_hashtbl[i].next, struct nfs4_client, cl_strhash);
destroy_client(clp);
}
}

node = rb_first(&unconf_name_tree);
while (node != NULL) {
tmp = node;
node = rb_next(tmp);
clp = rb_entry(tmp, struct nfs4_client, cl_namenode);
rb_erase(tmp, &unconf_name_tree);
destroy_client(clp);
}

INIT_LIST_HEAD(&reaplist);
spin_lock(&recall_lock);
list_for_each_safe(pos, next, &del_recall_lru) {
Expand Down
3 changes: 2 additions & 1 deletion fs/nfsd/state.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -232,7 +232,7 @@ struct nfsd4_sessionid {
*/
struct nfs4_client {
struct list_head cl_idhash; /* hash by cl_clientid.id */
struct list_head cl_strhash; /* hash by cl_name */
struct rb_node cl_namenode; /* link into by-name trees */
struct list_head cl_openowners;
struct idr cl_stateids; /* stateid lookup */
struct list_head cl_delegations;
Expand All @@ -253,6 +253,7 @@ struct nfs4_client {
#define NFSD4_CLIENT_CB_KILL (1)
#define NFSD4_CLIENT_STABLE (2) /* client on stable storage */
#define NFSD4_CLIENT_RECLAIM_COMPLETE (3) /* reclaim_complete done */
#define NFSD4_CLIENT_CONFIRMED (4) /* client is confirmed */
#define NFSD4_CLIENT_CB_FLAG_MASK (1 << NFSD4_CLIENT_CB_UPDATE | \
1 << NFSD4_CLIENT_CB_KILL)
unsigned long cl_flags;
Expand Down

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