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>
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 6b42440..ccb4550 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -130,7 +130,6 @@
#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 @@
#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
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index c97a0ad..44b56c9 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -70,19 +70,25 @@
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 @@
#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 @@
/* 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 *);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 84d0b7e..1840ebc 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -253,7 +253,7 @@
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 @@
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 @@
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 @@
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);
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 0f79d56..ab0b5ab 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -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 @@
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 @@
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 @@
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 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 @@
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 @@
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 @@
return NULL;
}
spin_unlock(&state->state_lock);
- kfree(new);
+ if (new != NULL)
+ nfs4_free_lock_state(new);
return lsp;
}
@@ -442,7 +553,7 @@
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 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 @@
{
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 @@
/* 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) {
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 4c8f67d..c087384 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -68,10 +68,10 @@
#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 @@
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 @@
{
__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 @@
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)