Clean up: Continue to rationalize the locking in nfs_get_client() by
moving the logic that handles the case where a matching server IP
address is not found.

When we support server trunking detection, client initialization may
return a different nfs_client struct than was passed to it. Change
the synopsis of the init_client methods to return an nfs_client.

The client initialization logic in nfs_get_client() is not much more
than a wrapper around ->init_client. It's simpler to keep the little
bits of error handling in the version-specific init_client methods.

No behavior change is expected.

Signed-off-by: Chuck Lever <[email protected]>
---

fs/nfs/client.c | 76 ++++++++++++++++++++++++++---------------------
fs/nfs/internal.h | 4 +-
include/linux/nfs_xdr.h | 3 +-
3 files changed, 46 insertions(+), 37 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 5f19f95..8a4b3c2 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -546,7 +546,6 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
int noresvport)
{
struct nfs_client *clp, *new = NULL;
- int error;
struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);

dprintk("--> nfs_get_client(%s,v%u)\n",
@@ -563,8 +562,13 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
nfs_free_client(new);
return nfs_found_client(cl_init, clp);
}
- if (new)
- goto install_client;
+ if (new) {
+ list_add(&new->cl_share_link, &nn->nfs_client_list);
+ spin_unlock(&nn->nfs_client_lock);
+ return cl_init->rpc_ops->init_client(new,
+ timeparms, ip_addr,
+ authflavour, noresvport);
+ }

spin_unlock(&nn->nfs_client_lock);

@@ -574,21 +578,6 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n",
cl_init->hostname ?: "", PTR_ERR(new));
return new;
-
- /* install a new client and return with it unready */
-install_client:
- clp = new;
- list_add(&clp->cl_share_link, &nn->nfs_client_list);
- spin_unlock(&nn->nfs_client_lock);
-
- error = cl_init->rpc_ops->init_client(clp, timeparms, ip_addr,
- authflavour, noresvport);
- if (error < 0) {
- nfs_put_client(clp);
- return ERR_PTR(error);
- }
- dprintk("--> nfs_get_client() = %p [new]\n", clp);
- return clp;
}

/*
@@ -813,10 +802,19 @@ static int nfs_init_server_rpcclient(struct nfs_server *server,
return 0;
}

-/*
- * Initialise an NFS2 or NFS3 client
+/**
+ * nfs_init_client - Initialise an NFS2 or NFS3 client
+ *
+ * @clp: nfs_client to initialise
+ * @timeparms: timeout parameters for underlying RPC transport
+ * @ip_addr: IP presentation address (not used)
+ * @authflavor: authentication flavor for underlying RPC transport
+ * @noresvport: set if RPC transport can use an ephemeral source port
+ *
+ * Returns pointer to an NFS client, or an ERR_PTR value.
*/
-int nfs_init_client(struct nfs_client *clp, const struct rpc_timeout *timeparms,
+struct nfs_client *nfs_init_client(struct nfs_client *clp,
+ const struct rpc_timeout *timeparms,
const char *ip_addr, rpc_authflavor_t authflavour,
int noresvport)
{
@@ -825,7 +823,7 @@ int nfs_init_client(struct nfs_client *clp, const struct rpc_timeout *timeparms,
if (clp->cl_cons_state == NFS_CS_READY) {
/* the client is already initialised */
dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
- return 0;
+ return clp;
}

/*
@@ -837,12 +835,13 @@ int nfs_init_client(struct nfs_client *clp, const struct rpc_timeout *timeparms,
if (error < 0)
goto error;
nfs_mark_client_ready(clp, NFS_CS_READY);
- return 0;
+ return clp;

error:
nfs_mark_client_ready(clp, error);
+ nfs_put_client(clp);
dprintk("<-- nfs_init_client() = xerror %d\n", error);
- return error;
+ return ERR_PTR(error);
}

/*
@@ -1358,14 +1357,22 @@ static int nfs4_init_client_minor_version(struct nfs_client *clp)
return nfs4_init_callback(clp);
}

-/*
- * Initialise an NFS4 client record
+/**
+ * nfs4_init_client - Initialise an NFS4 client record
+ *
+ * @clp: nfs_client to initialise
+ * @timeparms: timeout parameters for underlying RPC transport
+ * @ip_addr: callback IP address in presentation format
+ * @authflavor: authentication flavor for underlying RPC transport
+ * @noresvport: set if RPC transport can use an ephemeral source port
+ *
+ * Returns pointer to an NFS client, or an ERR_PTR value.
*/
-int nfs4_init_client(struct nfs_client *clp,
- const struct rpc_timeout *timeparms,
- const char *ip_addr,
- rpc_authflavor_t authflavour,
- int noresvport)
+struct nfs_client *nfs4_init_client(struct nfs_client *clp,
+ const struct rpc_timeout *timeparms,
+ const char *ip_addr,
+ rpc_authflavor_t authflavour,
+ int noresvport)
{
char buf[INET6_ADDRSTRLEN + 1];
int error;
@@ -1373,7 +1380,7 @@ int nfs4_init_client(struct nfs_client *clp,
if (clp->cl_cons_state == NFS_CS_READY) {
/* the client is initialised already */
dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
- return 0;
+ return clp;
}

/* Check NFS protocol revision and initialize RPC op vector */
@@ -1413,12 +1420,13 @@ int nfs4_init_client(struct nfs_client *clp,

if (!nfs4_has_session(clp))
nfs_mark_client_ready(clp, NFS_CS_READY);
- return 0;
+ return clp;

error:
nfs_mark_client_ready(clp, error);
+ nfs_put_client(clp);
dprintk("<-- nfs4_init_client() = xerror %d\n", error);
- return error;
+ return ERR_PTR(error);
}

/*
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 989959a..3a9e80c 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -238,7 +238,7 @@ extern int nfs4_init_ds_session(struct nfs_client *clp);

/* proc.c */
void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
-extern int nfs_init_client(struct nfs_client *clp,
+extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
const struct rpc_timeout *timeparms,
const char *ip_addr, rpc_authflavor_t authflavour,
int noresvport);
@@ -373,7 +373,7 @@ void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,

/* nfs4proc.c */
extern void __nfs4_read_done_cb(struct nfs_read_data *);
-extern int nfs4_init_client(struct nfs_client *clp,
+extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
const struct rpc_timeout *timeparms,
const char *ip_addr,
rpc_authflavor_t authflavour,
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index c420b8d..0c521cd 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1397,7 +1397,8 @@ struct nfs_rpc_ops {
struct nfs_open_context *ctx,
int open_flags,
struct iattr *iattr);
- int (*init_client) (struct nfs_client *, const struct rpc_timeout *,
+ struct nfs_client *
+ (*init_client) (struct nfs_client *, const struct rpc_timeout *,
const char *, rpc_authflavor_t, int);
};