NFSv4.1: pnfs: add LAYOUTGET and GETDEVICEINFO infrastructure

Add the ability to actually send LAYOUTGET and GETDEVICEINFO.  This also adds
in the machinery to handle layout state and the deviceid cache.  Note that
GETDEVICEINFO is not called directly by the generic layer.  Instead it
is called by the drivers while parsing the LAYOUTGET opaque data in response
to an unknown device id embedded therein.  RFC 5661 only encodes
device ids within the driver-specific opaque data.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Dean Hildebrand <dhildebz@umich.edu>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Ricardo Labiaga <ricardo.labiaga@netapp.com>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 72 insertions, 1 deletions

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 1c3eb02f4944..cbba28cb02a7 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -32,7 +32,7 @@
 
 struct pnfs_layout_segment {
         struct list_head fi_list;
-        u32 iomode;
+        struct pnfs_layout_range range;
         struct kref kref;
         struct pnfs_layout_hdr *layout;
 };
@@ -44,6 +44,7 @@ struct pnfs_layout_segment {
 enum {
         NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
         NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
+        NFS_LAYOUT_STATEID_SET,         /* have a valid layout stateid */
 };
 
 /* Per-layout driver specific registration structure */
@@ -54,26 +55,96 @@ struct pnfs_layoutdriver_type {
         struct module *owner;
         int (*initialize_mountpoint) (struct nfs_server *);
         int (*uninitialize_mountpoint) (struct nfs_server *);
+        struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);
+        void (*free_lseg) (struct pnfs_layout_segment *lseg);
 };
 
 struct pnfs_layout_hdr {
         unsigned long           refcount;
         struct list_head        layouts;   /* other client layouts */
         struct list_head        segs;      /* layout segments list */
+        seqlock_t               seqlock;   /* Protects the stateid */
+        nfs4_stateid            stateid;
         unsigned long           state;
         struct inode            *inode;
 };
 
+struct pnfs_device {
+        struct nfs4_deviceid dev_id;
+        unsigned int  layout_type;
+        unsigned int  mincount;
+        struct page **pages;
+        void          *area;
+        unsigned int  pgbase;
+        unsigned int  pglen;
+};
+
+/*
+ * Device ID RCU cache. A device ID is unique per client ID and layout type.
+ */
+#define NFS4_DEVICE_ID_HASH_BITS        5
+#define NFS4_DEVICE_ID_HASH_SIZE        (1 << NFS4_DEVICE_ID_HASH_BITS)
+#define NFS4_DEVICE_ID_HASH_MASK        (NFS4_DEVICE_ID_HASH_SIZE - 1)
+
+static inline u32
+nfs4_deviceid_hash(struct nfs4_deviceid *id)
+{
+        unsigned char *cptr = (unsigned char *)id->data;
+        unsigned int nbytes = NFS4_DEVICEID4_SIZE;
+        u32 x = 0;
+
+        while (nbytes--) {
+                x *= 37;
+                x += *cptr++;
+        }
+        return x & NFS4_DEVICE_ID_HASH_MASK;
+}
+
+struct pnfs_deviceid_node {
+        struct hlist_node       de_node;
+        struct nfs4_deviceid    de_id;
+        atomic_t                de_ref;
+};
+
+struct pnfs_deviceid_cache {
+        spinlock_t              dc_lock;
+        atomic_t                dc_ref;
+        void                    (*dc_free_callback)(struct pnfs_deviceid_node *);
+        struct hlist_head       dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
+};
+
+extern int pnfs_alloc_init_deviceid_cache(struct nfs_client *,
+                        void (*free_callback)(struct pnfs_deviceid_node *));
+extern void pnfs_put_deviceid_cache(struct nfs_client *);
+extern struct pnfs_deviceid_node *pnfs_find_get_deviceid(
+                                struct pnfs_deviceid_cache *,
+                                struct nfs4_deviceid *);
+extern struct pnfs_deviceid_node *pnfs_add_deviceid(
+                                struct pnfs_deviceid_cache *,
+                                struct pnfs_deviceid_node *);
+extern void pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
+                              struct pnfs_deviceid_node *devid);
+
 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 
+/* nfs4proc.c */
+extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
+                                   struct pnfs_device *dev);
+extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
+
+/* pnfs.c */
 struct pnfs_layout_segment *
 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
                    enum pnfs_iomode access_type);
 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
 void unset_pnfs_layoutdriver(struct nfs_server *);
+int pnfs_layout_process(struct nfs4_layoutget *lgp);
 void pnfs_destroy_layout(struct nfs_inode *);
 void pnfs_destroy_all_layouts(struct nfs_client *);
+void put_layout_hdr(struct inode *inode);
+void pnfs_get_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
+                             struct nfs4_state *open_state);
 
 
 static inline int lo_fail_bit(u32 iomode)