On Thu, 2013-09-05 at 13:30 -0400, andros@xxxxxxxxxx wrote:
> From: Andy Adamson <andros@xxxxxxxxxx>
>
> Commit 4edaa308 "NFS: Use "krb5i" to establish NFSv4 state whenever possible"
> uses the nfs_client cl_rpcclient for all state management operations, and
> will use krb5i or auth_sys with no regard to the mount command authflavor
> choice.
>
> The MDS, as any NFSv4.1 mount point, uses the nfs_server rpc client for all
> non-state management operations with a different nfs_server for each fsid
> encountered traversing the mount point, each with a potentially different
> auth flavor.
>
> pNFS data servers are not mounted in the normal sense as there is no associated
> nfs_server structure. Data servers can also export multiple fsids, each with
> a potentially different auth flavor.
>
> Data servers need to use the same authflavor as the MDS server rpc client for
> non-state management operations. Populate a list of rpc clients with the MDS
> server rpc client auth flavor for the DS to use.
>
> Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
> ---
> fs/nfs/internal.h | 2 +
> fs/nfs/nfs4client.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++
> fs/nfs/nfs4filelayout.c | 35 +++++++++++----
> include/linux/nfs_fs_sb.h | 1 +
> 4 files changed, 140 insertions(+), 8 deletions(-)
That looks a lot better. See comments inline below.
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index 2415198..23ec6e8 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -186,6 +186,8 @@ extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
> int ds_addrlen, int ds_proto,
> unsigned int ds_timeo,
> unsigned int ds_retrans);
> +extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
> + struct inode *);
> #ifdef CONFIG_PROC_FS
> extern int __init nfs_fs_proc_init(void);
> extern void nfs_fs_proc_exit(void);
> diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
> index 767a5e3..a8dd396 100644
> --- a/fs/nfs/nfs4client.c
> +++ b/fs/nfs/nfs4client.c
> @@ -49,10 +49,118 @@ static void nfs4_shutdown_session(struct nfs_client *clp)
> }
>
> }
> +
> +/**
> + * Per auth flavor data server rpc clients
> + */
> +struct nfs4_ds_server {
> + struct list_head list; /* ds_clp->cl_ds_clients */
> + struct rpc_clnt *rpc_clnt;
> +};
> +
> +static struct nfs4_ds_server *
> +nfs4_find_or_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
> + struct nfs4_ds_server *new)
> +{
> + struct nfs4_ds_server *dss, *tmp;
> +
> + spin_lock(&ds_clp->cl_lock);
> + list_for_each_entry_safe(dss, tmp, &ds_clp->cl_ds_clients, list) {
Nit: why do we need list_for_each_entry_safe() here? You're not removing
anything from that list.
> + if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
> + continue;
> + goto out;
> + }
> + if (new)
> + list_add(&new->list, &ds_clp->cl_ds_clients);
> + dss = new;
> +out:
> + spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
> + return dss;
> +}
> +
> +static struct nfs4_ds_server *
> +nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
> +{
> + struct nfs4_ds_server *dss;
> +
> + dss = kmalloc(sizeof(*dss), GFP_NOFS);
> + if (dss == NULL)
> + return ERR_PTR(-ENOMEM);
> +
> + dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
> + if (IS_ERR(dss->rpc_clnt)) {
> + int err = PTR_ERR(dss->rpc_clnt);
> + kfree (dss);
> + return ERR_PTR(err);
> + }
> + INIT_LIST_HEAD(&dss->list);
> +
> + return dss;
> +}
> +
> +static void
> +nfs4_free_ds_server(struct nfs4_ds_server *dss)
> +{
> + rpc_release_client(dss->rpc_clnt);
> + kfree(dss);
> +}
> +
> +/**
> + * Find or create a DS rpc client with th MDS server rpc client auth flavor
> + * in the nfs_client cl_ds_clients list.
> + */
> +struct rpc_clnt *
> +nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
> +{
> + struct nfs4_ds_server *dss, *new;
> + rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
> +
> + dss = nfs4_find_or_add_ds_client(ds_clp, flavor, NULL);
Does it make sense to perhaps use RCU in this case (but not the one
below) in order to avoid the contention on clp->cl_lock?
> + if (dss != NULL)
> + goto out;
> + new = nfs4_alloc_ds_server(ds_clp, flavor);
> + if (IS_ERR(new))
> + return (struct rpc_clnt *)new;
Nit: you should use ERR_CAST() rather than an explicit cast above
> + dss = nfs4_find_or_add_ds_client(ds_clp, flavor, new);
> + if (dss != new)
> + nfs4_free_ds_server(new);
> +out:
> + return dss->rpc_clnt;
> +}
> +EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
> +
> +static void
> +nfs4_shutdown_ds_clients(struct nfs_client *clp)
> +{
> + struct nfs4_ds_server *dss;
> + LIST_HEAD(shutdown_list);
> +
> + spin_lock(&clp->cl_lock);
> + while (!list_empty(&clp->cl_ds_clients)) {
> + dss = list_entry(clp->cl_ds_clients.next,
> + struct nfs4_ds_server, list);
> + list_move(&dss->list, &shutdown_list);
Is this step necessary? We know that nobody other than us is referencing
the nfs_client at this point.
> + }
> + spin_unlock(&clp->cl_lock);
> +
> + while (!list_empty(&shutdown_list)) {
> + dss = list_entry(shutdown_list.next,
> + struct nfs4_ds_server, list);
> + list_del(&dss->list);
> + rpc_shutdown_client(dss->rpc_clnt);
> + kfree (dss);
> + }
> +}
> +
> #else /* CONFIG_NFS_V4_1 */
> static void nfs4_shutdown_session(struct nfs_client *clp)
> {
> }
> +
> +static void
> +nfs4_shutdown_ds_clients(struct nfs_client *clp)
> +{
> +}
> #endif /* CONFIG_NFS_V4_1 */
>
> struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
> @@ -73,6 +181,7 @@ struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
>
> spin_lock_init(&clp->cl_lock);
> INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
> + INIT_LIST_HEAD(&clp->cl_ds_clients);
> rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
> clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
> clp->cl_minorversion = cl_init->minorversion;
> @@ -97,6 +206,7 @@ static void nfs4_shutdown_client(struct nfs_client *clp)
> {
> if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
> nfs4_kill_renewd(clp);
> + nfs4_shutdown_ds_clients(clp);
> nfs4_shutdown_session(clp);
> nfs4_destroy_callback(clp);
> if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
> diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
> index a70cb3a..b86464b 100644
> --- a/fs/nfs/nfs4filelayout.c
> +++ b/fs/nfs/nfs4filelayout.c
> @@ -528,6 +528,7 @@ filelayout_read_pagelist(struct nfs_read_data *data)
> struct nfs_pgio_header *hdr = data->header;
> struct pnfs_layout_segment *lseg = hdr->lseg;
> struct nfs4_pnfs_ds *ds;
> + struct rpc_clnt *ds_clnt;
> loff_t offset = data->args.offset;
> u32 j, idx;
> struct nfs_fh *fh;
> @@ -542,6 +543,11 @@ filelayout_read_pagelist(struct nfs_read_data *data)
> ds = nfs4_fl_prepare_ds(lseg, idx);
> if (!ds)
> return PNFS_NOT_ATTEMPTED;
> +
> + ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
> + if (IS_ERR(ds_clnt))
> + return PNFS_NOT_ATTEMPTED;
> +
> dprintk("%s USE DS: %s cl_count %d\n", __func__,
> ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
>
> @@ -556,7 +562,7 @@ filelayout_read_pagelist(struct nfs_read_data *data)
> data->mds_offset = offset;
>
> /* Perform an asynchronous read to ds */
> - nfs_initiate_read(ds->ds_clp->cl_rpcclient, data,
> + nfs_initiate_read(ds_clnt, data,
> &filelayout_read_call_ops, RPC_TASK_SOFTCONN);
> return PNFS_ATTEMPTED;
> }
> @@ -568,6 +574,7 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
> struct nfs_pgio_header *hdr = data->header;
> struct pnfs_layout_segment *lseg = hdr->lseg;
> struct nfs4_pnfs_ds *ds;
> + struct rpc_clnt *ds_clnt;
> loff_t offset = data->args.offset;
> u32 j, idx;
> struct nfs_fh *fh;
> @@ -578,6 +585,11 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
> ds = nfs4_fl_prepare_ds(lseg, idx);
> if (!ds)
> return PNFS_NOT_ATTEMPTED;
> +
> + ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
> + if (IS_ERR(ds_clnt))
> + return PNFS_NOT_ATTEMPTED;
> +
> dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
> __func__, hdr->inode->i_ino, sync, (size_t) data->args.count,
> offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
> @@ -595,7 +607,7 @@ filelayout_write_pagelist(struct nfs_write_data *data, int sync)
> data->args.offset = filelayout_get_dserver_offset(lseg, offset);
>
> /* Perform an asynchronous write */
> - nfs_initiate_write(ds->ds_clp->cl_rpcclient, data,
> + nfs_initiate_write(ds_clnt, data,
> &filelayout_write_call_ops, sync,
> RPC_TASK_SOFTCONN);
> return PNFS_ATTEMPTED;
> @@ -1105,16 +1117,19 @@ static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
> {
> struct pnfs_layout_segment *lseg = data->lseg;
> struct nfs4_pnfs_ds *ds;
> + struct rpc_clnt *ds_clnt;
> u32 idx;
> struct nfs_fh *fh;
>
> idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
> ds = nfs4_fl_prepare_ds(lseg, idx);
> - if (!ds) {
> - prepare_to_resend_writes(data);
> - filelayout_commit_release(data);
> - return -EAGAIN;
> - }
> + if (!ds)
> + goto out_err;
> +
> + ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
> + if (IS_ERR(ds_clnt))
> + goto out_err;
> +
> dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
> data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
> data->commit_done_cb = filelayout_commit_done_cb;
> @@ -1123,9 +1138,13 @@ static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
> fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
> if (fh)
> data->args.fh = fh;
> - return nfs_initiate_commit(ds->ds_clp->cl_rpcclient, data,
> + return nfs_initiate_commit(ds_clnt, data,
> &filelayout_commit_call_ops, how,
> RPC_TASK_SOFTCONN);
> +out_err:
> + prepare_to_resend_writes(data);
> + filelayout_commit_release(data);
> + return -EAGAIN;
> }
>
> static int
> diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
> index d221243..4d476e7 100644
> --- a/include/linux/nfs_fs_sb.h
> +++ b/include/linux/nfs_fs_sb.h
> @@ -56,6 +56,7 @@ struct nfs_client {
> struct rpc_cred *cl_machine_cred;
>
> #if IS_ENABLED(CONFIG_NFS_V4)
> + struct list_head cl_ds_clients; /* auth flavor data servers */
> u64 cl_clientid; /* constant */
> nfs4_verifier cl_confirm; /* Clientid verifier */
> unsigned long cl_state;
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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