nfs_delegation_find_inode currently has to walk the entire list of
delegations per inode, which can become pretty large, and can become even
larger when increasing the delegation watermark.
Add a hash table to speed up the delegation lookup, sized as a fraction
of the delegation watermark.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/nfs/client.c | 14 +++++++++++---
fs/nfs/delegation.c | 28 +++++++++++++++++++++++++++-
fs/nfs/delegation.h | 3 +++
fs/nfs/nfs4client.c | 10 +++++++++-
include/linux/nfs_fs_sb.h | 2 ++
5 files changed, 52 insertions(+), 5 deletions(-)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index e13eb429b8b5..5e1a5263e326 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1158,6 +1158,12 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source,
server->fsid = fattr->fsid;
+ if (IS_ENABLED(CONFIG_NFS_V4) && server->delegation_hash_table) {
+ error = nfs4_delegation_hash_alloc(server);
+ if (error)
+ goto out_free_server;
+ }
+
nfs_sysfs_add_server(server);
nfs_sysfs_link_rpc_client(server,
@@ -1167,25 +1173,27 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source,
source->client->cl_timeout,
flavor);
if (error < 0)
- goto out_free_server;
+ goto out_free_delegation_hash;
/* probe the filesystem info for this server filesystem */
error = nfs_probe_server(server, fh);
if (error < 0)
- goto out_free_server;
+ goto out_free_delegation_hash;
if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
server->namelen = NFS4_MAXNAMLEN;
error = nfs_start_lockd(server);
if (error < 0)
- goto out_free_server;
+ goto out_free_delegation_hash;
nfs_server_insert_lists(server);
server->mount_time = jiffies;
return server;
+out_free_delegation_hash:
+ kfree(server->delegation_hash_table);
out_free_server:
nfs_free_server(server);
return ERR_PTR(error);
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index ea96f77e38c2..9d3a5f29f17f 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -30,6 +30,13 @@
static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK;
module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644);
+static struct hlist_head *nfs_delegation_hash(struct nfs_server *server,
+ const struct nfs_fh *fhandle)
+{
+ return server->delegation_hash_table +
+ (nfs_fhandle_hash(fhandle) & server->delegation_hash_mask);
+}
+
static void __nfs_free_delegation(struct nfs_delegation *delegation)
{
put_cred(delegation->cred);
@@ -367,6 +374,7 @@ nfs_detach_delegation_locked(struct nfs_inode *nfsi,
spin_unlock(&delegation->lock);
return NULL;
}
+ hlist_del_init_rcu(&delegation->hash);
list_del_rcu(&delegation->super_list);
delegation->inode = NULL;
rcu_assign_pointer(nfsi->delegation, NULL);
@@ -529,6 +537,8 @@ int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
spin_unlock(&inode->i_lock);
list_add_tail_rcu(&delegation->super_list, &server->delegations);
+ hlist_add_head_rcu(&delegation->hash,
+ nfs_delegation_hash(server, &NFS_I(inode)->fh));
rcu_assign_pointer(nfsi->delegation, delegation);
delegation = NULL;
@@ -1166,11 +1176,12 @@ static struct inode *
nfs_delegation_find_inode_server(struct nfs_server *server,
const struct nfs_fh *fhandle)
{
+ struct hlist_head *head = nfs_delegation_hash(server, fhandle);
struct nfs_delegation *delegation;
struct super_block *freeme = NULL;
struct inode *res = NULL;
- list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+ hlist_for_each_entry_rcu(delegation, head, hash) {
spin_lock(&delegation->lock);
if (delegation->inode != NULL &&
!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
@@ -1577,3 +1588,18 @@ bool nfs4_delegation_flush_on_close(const struct inode *inode)
rcu_read_unlock();
return ret;
}
+
+int nfs4_delegation_hash_alloc(struct nfs_server *server)
+{
+ int delegation_buckets, i;
+
+ delegation_buckets = roundup_pow_of_two(nfs_delegation_watermark / 16);
+ server->delegation_hash_mask = delegation_buckets - 1;
+ server->delegation_hash_table = kmalloc_array(delegation_buckets,
+ sizeof(*server->delegation_hash_table), GFP_KERNEL);
+ if (!server->delegation_hash_table)
+ return -ENOMEM;
+ for (i = 0; i < delegation_buckets; i++)
+ INIT_HLIST_HEAD(&server->delegation_hash_table[i]);
+ return 0;
+}
diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h
index 8ff5ab9c5c25..08ec2e9c68a4 100644
--- a/fs/nfs/delegation.h
+++ b/fs/nfs/delegation.h
@@ -14,6 +14,7 @@
* NFSv4 delegation
*/
struct nfs_delegation {
+ struct hlist_node hash;
struct list_head super_list;
const struct cred *cred;
struct inode *inode;
@@ -123,4 +124,6 @@ static inline int nfs_have_delegated_mtime(struct inode *inode)
NFS_DELEGATION_FLAG_TIME);
}
+int nfs4_delegation_hash_alloc(struct nfs_server *server);
+
#endif
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 2e623da1a787..31dc0d40209a 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -802,6 +802,7 @@ static void nfs4_destroy_server(struct nfs_server *server)
unset_pnfs_layoutdriver(server);
nfs4_purge_state_owners(server, &freeme);
nfs4_free_state_owners(&freeme);
+ kfree(server->delegation_hash_table);
}
/*
@@ -1096,9 +1097,14 @@ static int nfs4_server_common_setup(struct nfs_server *server,
{
int error;
+ error = nfs4_delegation_hash_alloc(server);
+ if (error)
+ return error;
+
/* data servers support only a subset of NFSv4.1 */
+ error = -EPROTONOSUPPORT;
if (is_ds_only_client(server->nfs_client))
- return -EPROTONOSUPPORT;
+ goto out;
/* We must ensure the session is initialised first */
error = nfs4_init_session(server->nfs_client);
@@ -1130,7 +1136,9 @@ static int nfs4_server_common_setup(struct nfs_server *server,
nfs_server_insert_lists(server);
server->mount_time = jiffies;
server->destroy = nfs4_destroy_server;
+ return 0;
out:
+ kfree(server->delegation_hash_table);
return error;
}
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index a9b44f12623f..d30c0245031c 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -255,6 +255,8 @@ struct nfs_server {
struct list_head layouts;
struct list_head delegations;
atomic_long_t nr_active_delegations;
+ unsigned int delegation_hash_mask;
+ struct hlist_head *delegation_hash_table;
struct list_head ss_copies;
struct list_head ss_src_copies;
--
2.47.2
