NFS: Generalise the nfs_client structure

Generalise the nfs_client structure by:

 (1) Moving nfs_client to a more general place (nfs_fs_sb.h).

 (2) Renaming its maintenance routines to be non-NFS4 specific.

 (3) Move those maintenance routines to a new non-NFS4 specific file (client.c)
     and move the declarations to internal.h.

 (4) Make nfs_find/get_client() take a full sockaddr_in to include the port
     number (will be required for NFS2/3).

 (5) Make nfs_find/get_client() take the NFS protocol version (again will be
     required to differentiate NFS2, 3 & 4 client records).

Also:

 (6) Make nfs_client construction proceed akin to inodes, marking them as under
     construction and providing a function to indicate completion.

 (7) Make nfs_get_client() wait interruptibly if it finds a client that it can
     share, but that client is currently being constructed.

 (8) Make nfs4_create_client() use (6) and (7) instead of locking cl_sem.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 61 insertions, 0 deletions

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index a36e01cd6321..70e1dc9162e2 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -586,6 +586,7 @@ extern void * nfs_root_data(void);
 #define NFSDBG_FILE             0x0040
 #define NFSDBG_ROOT             0x0080
 #define NFSDBG_CALLBACK         0x0100
+#define NFSDBG_CLIENT           0x0200
 #define NFSDBG_ALL              0xFFFF
 
 #ifdef __KERNEL__
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index fc20d6b934fb..a727657e0ad3 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -7,6 +7,66 @@
 struct nfs_iostats;
 
 /*
+ * The nfs_client identifies our client state to the server.
+ */
+struct nfs_client {
+        atomic_t                cl_count;
+        int                     cl_cons_state;  /* current construction state (-ve: init error) */
+#define NFS_CS_READY            0               /* ready to be used */
+#define NFS_CS_INITING          1               /* busy initialising */
+        int                     cl_nfsversion;  /* NFS protocol version */
+        unsigned long           cl_res_state;   /* NFS resources state */
+#define NFS_CS_RPCIOD           0               /* - rpciod started */
+#define NFS_CS_CALLBACK         1               /* - callback started */
+#define NFS_CS_IDMAP            2               /* - idmap started */
+        struct sockaddr_in      cl_addr;        /* server identifier */
+        char *                  cl_hostname;    /* hostname of server */
+        struct list_head        cl_share_link;  /* link in global client list */
+        struct list_head        cl_superblocks; /* List of nfs_server structs */
+
+        struct rpc_clnt *       cl_rpcclient;
+
+#ifdef CONFIG_NFS_V4
+        u64                     cl_clientid;    /* constant */
+        nfs4_verifier           cl_confirm;
+        unsigned long           cl_state;
+
+        u32                     cl_lockowner_id;
+
+        /*
+         * The following rwsem ensures exclusive access to the server
+         * while we recover the state following a lease expiration.
+         */
+        struct rw_semaphore     cl_sem;
+
+        struct list_head        cl_delegations;
+        struct list_head        cl_state_owners;
+        struct list_head        cl_unused;
+        int                     cl_nunused;
+        spinlock_t              cl_lock;
+
+        unsigned long           cl_lease_time;
+        unsigned long           cl_last_renewal;
+        struct work_struct      cl_renewd;
+        struct work_struct      cl_recoverd;
+
+        struct rpc_wait_queue   cl_rpcwaitq;
+
+        /* used for the setclientid verifier */
+        struct timespec         cl_boot_time;
+
+        /* idmapper */
+        struct idmap *          cl_idmap;
+
+        /* Our own IP address, as a null-terminated string.
+         * This is used to generate the clientid, and the callback address.
+         */
+        char                    cl_ipaddr[16];
+        unsigned char           cl_id_uniquifier;
+#endif
+};
+
+/*
  * NFS client parameters stored in the superblock.
  */
 struct nfs_server {