NFSv4: Reduce the chances of an open_owner identifier collision

Currently we just use a 32-bit counter.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2007-07-02 13:58:33 -04:00
parent 88d9093997
commit 9f958ab885
7 changed files with 190 additions and 67 deletions

View file

@ -130,7 +130,6 @@ static struct nfs_client *nfs_alloc_client(const char *hostname,
#ifdef CONFIG_NFS_V4
init_rwsem(&clp->cl_sem);
INIT_LIST_HEAD(&clp->cl_delegations);
INIT_LIST_HEAD(&clp->cl_state_owners);
spin_lock_init(&clp->cl_lock);
INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
@ -154,7 +153,7 @@ static void nfs4_shutdown_client(struct nfs_client *clp)
#ifdef CONFIG_NFS_V4
if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
nfs4_kill_renewd(clp);
BUG_ON(!list_empty(&clp->cl_state_owners));
BUG_ON(!RB_EMPTY_ROOT(&clp->cl_state_owners));
if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
nfs_idmap_delete(clp);
#endif

View file

@ -70,19 +70,25 @@ static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status
seqid->flags |= NFS_SEQID_CONFIRMED;
}
struct nfs_unique_id {
struct rb_node rb_node;
__u64 id;
};
/*
* NFS4 state_owners and lock_owners are simply labels for ordered
* sequences of RPC calls. Their sole purpose is to provide once-only
* semantics by allowing the server to identify replayed requests.
*/
struct nfs4_state_owner {
spinlock_t so_lock;
struct list_head so_list; /* per-clientid list of state_owners */
struct nfs_unique_id so_owner_id;
struct nfs_client *so_client;
u32 so_id; /* 32-bit identifier, unique */
atomic_t so_count;
struct rb_node so_client_node;
struct rpc_cred *so_cred; /* Associated cred */
spinlock_t so_lock;
atomic_t so_count;
struct list_head so_states;
struct list_head so_delegations;
struct nfs_seqid_counter so_seqid;
@ -108,7 +114,7 @@ struct nfs4_lock_state {
#define NFS_LOCK_INITIALIZED 1
int ls_flags;
struct nfs_seqid_counter ls_seqid;
u32 ls_id;
struct nfs_unique_id ls_id;
nfs4_stateid ls_stateid;
atomic_t ls_count;
};
@ -189,7 +195,6 @@ extern void nfs4_renew_state(struct work_struct *);
/* nfs4state.c */
struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp);
extern u32 nfs4_alloc_lockowner_id(struct nfs_client *);
extern struct nfs4_state_owner * nfs4_get_state_owner(struct nfs_server *, struct rpc_cred *);
extern void nfs4_put_state_owner(struct nfs4_state_owner *);

View file

@ -253,7 +253,7 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct path *path,
p->o_arg.fh = NFS_FH(dir);
p->o_arg.open_flags = flags,
p->o_arg.clientid = server->nfs_client->cl_clientid;
p->o_arg.id = sp->so_id;
p->o_arg.id = sp->so_owner_id.id;
p->o_arg.name = &p->path.dentry->d_name;
p->o_arg.server = server;
p->o_arg.bitmask = server->attr_bitmask;
@ -651,7 +651,7 @@ static void nfs4_open_prepare(struct rpc_task *task, void *calldata)
if (nfs_wait_on_sequence(data->o_arg.seqid, task) != 0)
return;
/* Update sequence id. */
data->o_arg.id = sp->so_id;
data->o_arg.id = sp->so_owner_id.id;
data->o_arg.clientid = sp->so_client->cl_clientid;
if (data->o_arg.claim == NFS4_OPEN_CLAIM_PREVIOUS)
msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_NOATTR];
@ -3029,7 +3029,7 @@ static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock
if (status != 0)
goto out;
lsp = request->fl_u.nfs4_fl.owner;
arg.lock_owner.id = lsp->ls_id;
arg.lock_owner.id = lsp->ls_id.id;
status = rpc_call_sync(server->client, &msg, 0);
switch (status) {
case 0:
@ -3243,7 +3243,7 @@ static struct nfs4_lockdata *nfs4_alloc_lockdata(struct file_lock *fl,
goto out_free;
p->arg.lock_stateid = &lsp->ls_stateid;
p->arg.lock_owner.clientid = server->nfs_client->cl_clientid;
p->arg.lock_owner.id = lsp->ls_id;
p->arg.lock_owner.id = lsp->ls_id.id;
p->lsp = lsp;
atomic_inc(&lsp->ls_count);
p->ctx = get_nfs_open_context(ctx);

View file

@ -44,6 +44,7 @@
#include <linux/nfs_idmap.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>
@ -69,18 +70,14 @@ static int nfs4_init_client(struct nfs_client *clp, struct rpc_cred *cred)
return status;
}
u32
nfs4_alloc_lockowner_id(struct nfs_client *clp)
{
return clp->cl_lockowner_id ++;
}
struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp)
{
struct nfs4_state_owner *sp;
struct rb_node *pos;
struct rpc_cred *cred = NULL;
list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
if (list_empty(&sp->so_states))
continue;
cred = get_rpccred(sp->so_cred);
@ -92,32 +89,129 @@ struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp)
static struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
{
struct nfs4_state_owner *sp;
struct rb_node *pos;
if (!list_empty(&clp->cl_state_owners)) {
sp = list_entry(clp->cl_state_owners.next,
struct nfs4_state_owner, so_list);
pos = rb_first(&clp->cl_state_owners);
if (pos != NULL) {
sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
return get_rpccred(sp->so_cred);
}
return NULL;
}
static void nfs_alloc_unique_id(struct rb_root *root, struct nfs_unique_id *new,
__u64 minval, int maxbits)
{
struct rb_node **p, *parent;
struct nfs_unique_id *pos;
__u64 mask = ~0ULL;
if (maxbits < 64)
mask = (1ULL << maxbits) - 1ULL;
/* Ensure distribution is more or less flat */
get_random_bytes(&new->id, sizeof(new->id));
new->id &= mask;
if (new->id < minval)
new->id += minval;
retry:
p = &root->rb_node;
parent = NULL;
while (*p != NULL) {
parent = *p;
pos = rb_entry(parent, struct nfs_unique_id, rb_node);
if (new->id < pos->id)
p = &(*p)->rb_left;
else if (new->id > pos->id)
p = &(*p)->rb_right;
else
goto id_exists;
}
rb_link_node(&new->rb_node, parent, p);
rb_insert_color(&new->rb_node, root);
return;
id_exists:
for (;;) {
new->id++;
if (new->id < minval || (new->id & mask) != new->id) {
new->id = minval;
break;
}
parent = rb_next(parent);
if (parent == NULL)
break;
pos = rb_entry(parent, struct nfs_unique_id, rb_node);
if (new->id < pos->id)
break;
}
goto retry;
}
static void nfs_free_unique_id(struct rb_root *root, struct nfs_unique_id *id)
{
rb_erase(&id->rb_node, root);
}
static struct nfs4_state_owner *
nfs4_find_state_owner(struct nfs_client *clp, struct rpc_cred *cred)
{
struct rb_node **p = &clp->cl_state_owners.rb_node,
*parent = NULL;
struct nfs4_state_owner *sp, *res = NULL;
list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
if (sp->so_cred != cred)
continue;
atomic_inc(&sp->so_count);
/* Move to the head of the list */
list_move(&sp->so_list, &clp->cl_state_owners);
res = sp;
break;
while (*p != NULL) {
parent = *p;
sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
if (cred < sp->so_cred)
p = &parent->rb_left;
else if (cred > sp->so_cred)
p = &parent->rb_right;
else {
atomic_inc(&sp->so_count);
res = sp;
break;
}
}
return res;
}
static struct nfs4_state_owner *
nfs4_insert_state_owner(struct nfs_client *clp, struct nfs4_state_owner *new)
{
struct rb_node **p = &clp->cl_state_owners.rb_node,
*parent = NULL;
struct nfs4_state_owner *sp;
while (*p != NULL) {
parent = *p;
sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
if (new->so_cred < sp->so_cred)
p = &parent->rb_left;
else if (new->so_cred > sp->so_cred)
p = &parent->rb_right;
else {
atomic_inc(&sp->so_count);
return sp;
}
}
nfs_alloc_unique_id(&clp->cl_openowner_id, &new->so_owner_id, 1, 64);
rb_link_node(&new->so_client_node, parent, p);
rb_insert_color(&new->so_client_node, &clp->cl_state_owners);
return new;
}
static void
nfs4_remove_state_owner(struct nfs_client *clp, struct nfs4_state_owner *sp)
{
if (!RB_EMPTY_NODE(&sp->so_client_node))
rb_erase(&sp->so_client_node, &clp->cl_state_owners);
nfs_free_unique_id(&clp->cl_openowner_id, &sp->so_owner_id);
}
/*
* nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
* create a new state_owner.
@ -145,10 +239,14 @@ nfs4_alloc_state_owner(void)
void
nfs4_drop_state_owner(struct nfs4_state_owner *sp)
{
struct nfs_client *clp = sp->so_client;
spin_lock(&clp->cl_lock);
list_del_init(&sp->so_list);
spin_unlock(&clp->cl_lock);
if (!RB_EMPTY_NODE(&sp->so_client_node)) {
struct nfs_client *clp = sp->so_client;
spin_lock(&clp->cl_lock);
rb_erase(&sp->so_client_node, &clp->cl_state_owners);
RB_CLEAR_NODE(&sp->so_client_node);
spin_unlock(&clp->cl_lock);
}
}
/*
@ -160,22 +258,24 @@ struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct
struct nfs_client *clp = server->nfs_client;
struct nfs4_state_owner *sp, *new;
new = nfs4_alloc_state_owner();
spin_lock(&clp->cl_lock);
sp = nfs4_find_state_owner(clp, cred);
if (sp == NULL && new != NULL) {
list_add(&new->so_list, &clp->cl_state_owners);
new->so_client = clp;
new->so_id = nfs4_alloc_lockowner_id(clp);
new->so_cred = get_rpccred(cred);
sp = new;
new = NULL;
}
spin_unlock(&clp->cl_lock);
kfree(new);
if (sp != NULL)
return sp;
return NULL;
new = nfs4_alloc_state_owner();
if (new == NULL)
return NULL;
new->so_client = clp;
new->so_cred = cred;
spin_lock(&clp->cl_lock);
sp = nfs4_insert_state_owner(clp, new);
spin_unlock(&clp->cl_lock);
if (sp == new)
get_rpccred(cred);
else
kfree(new);
return sp;
}
/*
@ -189,7 +289,7 @@ void nfs4_put_state_owner(struct nfs4_state_owner *sp)
if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
return;
list_del(&sp->so_list);
nfs4_remove_state_owner(clp, sp);
spin_unlock(&clp->cl_lock);
put_rpccred(cred);
kfree(sp);
@ -386,12 +486,22 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f
atomic_set(&lsp->ls_count, 1);
lsp->ls_owner = fl_owner;
spin_lock(&clp->cl_lock);
lsp->ls_id = nfs4_alloc_lockowner_id(clp);
nfs_alloc_unique_id(&clp->cl_lockowner_id, &lsp->ls_id, 1, 64);
spin_unlock(&clp->cl_lock);
INIT_LIST_HEAD(&lsp->ls_locks);
return lsp;
}
static void nfs4_free_lock_state(struct nfs4_lock_state *lsp)
{
struct nfs_client *clp = lsp->ls_state->owner->so_client;
spin_lock(&clp->cl_lock);
nfs_free_unique_id(&clp->cl_lockowner_id, &lsp->ls_id);
spin_unlock(&clp->cl_lock);
kfree(lsp);
}
/*
* Return a compatible lock_state. If no initialized lock_state structure
* exists, return an uninitialized one.
@ -421,7 +531,8 @@ static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_
return NULL;
}
spin_unlock(&state->state_lock);
kfree(new);
if (new != NULL)
nfs4_free_lock_state(new);
return lsp;
}
@ -442,7 +553,7 @@ void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
if (list_empty(&state->lock_states))
clear_bit(LK_STATE_IN_USE, &state->flags);
spin_unlock(&state->state_lock);
kfree(lsp);
nfs4_free_lock_state(lsp);
}
static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
@ -719,11 +830,13 @@ static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct n
static void nfs4_state_mark_reclaim(struct nfs_client *clp)
{
struct nfs4_state_owner *sp;
struct rb_node *pos;
struct nfs4_state *state;
struct nfs4_lock_state *lock;
/* Reset all sequence ids to zero */
list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
sp->so_seqid.counter = 0;
sp->so_seqid.flags = 0;
spin_lock(&sp->so_lock);
@ -742,6 +855,7 @@ static int reclaimer(void *ptr)
{
struct nfs_client *clp = ptr;
struct nfs4_state_owner *sp;
struct rb_node *pos;
struct nfs4_state_recovery_ops *ops;
struct rpc_cred *cred;
int status = 0;
@ -787,7 +901,8 @@ static int reclaimer(void *ptr)
/* Mark all delegations for reclaim */
nfs_delegation_mark_reclaim(clp);
/* Note: list is protected by exclusive lock on cl->cl_sem */
list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
status = nfs4_reclaim_open_state(ops, sp);
if (status < 0) {
if (status == -NFS4ERR_NO_GRACE) {

View file

@ -68,10 +68,10 @@ static int nfs4_stat_to_errno(int);
#endif
/* lock,open owner id:
* we currently use size 1 (u32) out of (NFS4_OPAQUE_LIMIT >> 2)
* we currently use size 2 (u64) out of (NFS4_OPAQUE_LIMIT >> 2)
*/
#define open_owner_id_maxsz (1 + 1)
#define lock_owner_id_maxsz (1 + 1)
#define open_owner_id_maxsz (1 + 4)
#define lock_owner_id_maxsz (1 + 4)
#define compound_encode_hdr_maxsz (3 + (NFS4_MAXTAGLEN >> 2))
#define compound_decode_hdr_maxsz (3 + (NFS4_MAXTAGLEN >> 2))
#define op_encode_hdr_maxsz (1)
@ -827,13 +827,14 @@ static int encode_lock(struct xdr_stream *xdr, const struct nfs_lock_args *args)
WRITE64(nfs4_lock_length(args->fl));
WRITE32(args->new_lock_owner);
if (args->new_lock_owner){
RESERVE_SPACE(4+NFS4_STATEID_SIZE+20);
RESERVE_SPACE(4+NFS4_STATEID_SIZE+32);
WRITE32(args->open_seqid->sequence->counter);
WRITEMEM(args->open_stateid->data, NFS4_STATEID_SIZE);
WRITE32(args->lock_seqid->sequence->counter);
WRITE64(args->lock_owner.clientid);
WRITE32(4);
WRITE32(args->lock_owner.id);
WRITE32(16);
WRITEMEM("lock id:", 8);
WRITE64(args->lock_owner.id);
}
else {
RESERVE_SPACE(NFS4_STATEID_SIZE+4);
@ -848,14 +849,15 @@ static int encode_lockt(struct xdr_stream *xdr, const struct nfs_lockt_args *arg
{
__be32 *p;
RESERVE_SPACE(40);
RESERVE_SPACE(52);
WRITE32(OP_LOCKT);
WRITE32(nfs4_lock_type(args->fl, 0));
WRITE64(args->fl->fl_start);
WRITE64(nfs4_lock_length(args->fl));
WRITE64(args->lock_owner.clientid);
WRITE32(4);
WRITE32(args->lock_owner.id);
WRITE32(16);
WRITEMEM("lock id:", 8);
WRITE64(args->lock_owner.id);
return 0;
}
@ -920,10 +922,11 @@ static inline void encode_openhdr(struct xdr_stream *xdr, const struct nfs_opena
WRITE32(OP_OPEN);
WRITE32(arg->seqid->sequence->counter);
encode_share_access(xdr, arg->open_flags);
RESERVE_SPACE(16);
RESERVE_SPACE(28);
WRITE64(arg->clientid);
WRITE32(4);
WRITE32(arg->id);
WRITE32(16);
WRITEMEM("open id:", 8);
WRITE64(arg->id);
}
static inline void encode_createmode(struct xdr_stream *xdr, const struct nfs_openargs *arg)

View file

@ -34,7 +34,8 @@ struct nfs_client {
nfs4_verifier cl_confirm;
unsigned long cl_state;
u32 cl_lockowner_id;
struct rb_root cl_openowner_id;
struct rb_root cl_lockowner_id;
/*
* The following rwsem ensures exclusive access to the server
@ -43,7 +44,7 @@ struct nfs_client {
struct rw_semaphore cl_sem;
struct list_head cl_delegations;
struct list_head cl_state_owners;
struct rb_root cl_state_owners;
spinlock_t cl_lock;
unsigned long cl_lease_time;

View file

@ -119,7 +119,7 @@ struct nfs_openargs {
struct nfs_seqid * seqid;
int open_flags;
__u64 clientid;
__u32 id;
__u64 id;
union {
struct iattr * attrs; /* UNCHECKED, GUARDED */
nfs4_verifier verifier; /* EXCLUSIVE */
@ -181,7 +181,7 @@ struct nfs_closeres {
* */
struct nfs_lowner {
__u64 clientid;
u32 id;
__u64 id;
};
struct nfs_lock_args {