pnfs: change how lsegs are removed from layout list

[mirror_ubuntu-bionic-kernel.git] / fs / nfs / pnfs.h

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 61531f3385761d7ed7db6536ae8ac8bd15d53fc0..787253e6fca351365c7e75aa825e2105c2277e2b 100644 (file)
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -30,28 +30,157 @@
 #ifndef FS_NFS_PNFS_H
 #define FS_NFS_PNFS_H
 
+enum {
+       NFS_LSEG_VALID = 0,     /* cleared when lseg is recalled/returned */
+};
+
+struct pnfs_layout_segment {
+       struct list_head pls_list;
+       struct pnfs_layout_range pls_range;
+       atomic_t pls_refcount;
+       unsigned long pls_flags;
+       struct pnfs_layout_hdr *pls_layout;
+};
+
 #ifdef CONFIG_NFS_V4_1
 
 #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
 
+enum {
+       NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
+       NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
+       NFS_LAYOUT_DESTROYED,           /* no new use of layout allowed */
+};
+
 /* Per-layout driver specific registration structure */
 struct pnfs_layoutdriver_type {
        struct list_head pnfs_tblid;
        const u32 id;
        const char *name;
        struct module *owner;
-       int (*initialize_mountpoint) (struct nfs_server *);
-       int (*uninitialize_mountpoint) (struct nfs_server *);
+       int (*set_layoutdriver) (struct nfs_server *);
+       int (*clear_layoutdriver) (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           plh_refcount;
+       struct list_head        plh_layouts;   /* other client layouts */
+       struct list_head        plh_segs;      /* layout segments list */
+       nfs4_stateid            plh_stateid;
+       unsigned long           plh_flags;
+       struct inode            *plh_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);
+int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
+                                 struct pnfs_layout_hdr *lo,
+                                 struct nfs4_state *open_state);
+
+
+static inline int lo_fail_bit(u32 iomode)
+{
+       return iomode == IOMODE_RW ?
+                        NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
+}
+
+/* Return true if a layout driver is being used for this mountpoint */
+static inline int pnfs_enabled_sb(struct nfs_server *nfss)
+{
+       return nfss->pnfs_curr_ld != NULL;
+}
 
 #else  /* CONFIG_NFS_V4_1 */
 
+static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
+{
+}
+
+static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
+{
+}
+
+static inline struct pnfs_layout_segment *
+pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
+                  enum pnfs_iomode access_type)
+{
+       return NULL;
+}
+
 static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
 {
 }