fs/nfs/pnfs.h

   1 /*
   2  *  pNFS client data structures.
   3  *
   4  *  Copyright (c) 2002
   5  *  The Regents of the University of Michigan
   6  *  All Rights Reserved
   7  *
   8  *  Dean Hildebrand <dhildebz@umich.edu>
   9  *
  10  *  Permission is granted to use, copy, create derivative works, and
  11  *  redistribute this software and such derivative works for any purpose,
  12  *  so long as the name of the University of Michigan is not used in
  13  *  any advertising or publicity pertaining to the use or distribution
  14  *  of this software without specific, written prior authorization. If
  15  *  the above copyright notice or any other identification of the
  16  *  University of Michigan is included in any copy of any portion of
  17  *  this software, then the disclaimer below must also be included.
  18  *
  19  *  This software is provided as is, without representation or warranty
  20  *  of any kind either express or implied, including without limitation
  21  *  the implied warranties of merchantability, fitness for a particular
  22  *  purpose, or noninfringement.  The Regents of the University of
  23  *  Michigan shall not be liable for any damages, including special,
  24  *  indirect, incidental, or consequential damages, with respect to any
  25  *  claim arising out of or in connection with the use of the software,
  26  *  even if it has been or is hereafter advised of the possibility of
  27  *  such damages.
  28  */
  29
  30 #ifndef FS_NFS_PNFS_H
  31 #define FS_NFS_PNFS_H
  32
  33 struct pnfs_layout_segment {
  34         struct list_head pls_list;
  35         struct pnfs_layout_range pls_range;
  36         struct kref pls_refcount;
  37         struct pnfs_layout_hdr *pls_layout;
  38 };
  39
  40 #ifdef CONFIG_NFS_V4_1
  41
  42 #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
  43
  44 enum {
  45         NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
  46         NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
  47 };
  48
  49 /* Per-layout driver specific registration structure */
  50 struct pnfs_layoutdriver_type {
  51         struct list_head pnfs_tblid;
  52         const u32 id;
  53         const char *name;
  54         struct module *owner;
  55         int (*set_layoutdriver) (struct nfs_server *);
  56         int (*clear_layoutdriver) (struct nfs_server *);
  57         struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);
  58         void (*free_lseg) (struct pnfs_layout_segment *lseg);
  59 };
  60
  61 struct pnfs_layout_hdr {
  62         unsigned long           plh_refcount;
  63         struct list_head        plh_layouts;   /* other client layouts */
  64         struct list_head        plh_segs;      /* layout segments list */
  65         nfs4_stateid            plh_stateid;
  66         unsigned long           plh_flags;
  67         struct inode            *plh_inode;
  68 };
  69
  70 struct pnfs_device {
  71         struct nfs4_deviceid dev_id;
  72         unsigned int  layout_type;
  73         unsigned int  mincount;
  74         struct page **pages;
  75         void          *area;
  76         unsigned int  pgbase;
  77         unsigned int  pglen;
  78 };
  79
  80 /*
  81  * Device ID RCU cache. A device ID is unique per client ID and layout type.
  82  */
  83 #define NFS4_DEVICE_ID_HASH_BITS        5
  84 #define NFS4_DEVICE_ID_HASH_SIZE        (1 << NFS4_DEVICE_ID_HASH_BITS)
  85 #define NFS4_DEVICE_ID_HASH_MASK        (NFS4_DEVICE_ID_HASH_SIZE - 1)
  86
  87 static inline u32
  88 nfs4_deviceid_hash(struct nfs4_deviceid *id)
  89 {
  90         unsigned char *cptr = (unsigned char *)id->data;
  91         unsigned int nbytes = NFS4_DEVICEID4_SIZE;
  92         u32 x = 0;
  93
  94         while (nbytes--) {
  95                 x *= 37;
  96                 x += *cptr++;
  97         }
  98         return x & NFS4_DEVICE_ID_HASH_MASK;
  99 }
 100
 101 struct pnfs_deviceid_node {
 102         struct hlist_node       de_node;
 103         struct nfs4_deviceid    de_id;
 104         atomic_t                de_ref;
 105 };
 106
 107 struct pnfs_deviceid_cache {
 108         spinlock_t              dc_lock;
 109         atomic_t                dc_ref;
 110         void                    (*dc_free_callback)(struct pnfs_deviceid_node *);
 111         struct hlist_head       dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
 112 };
 113
 114 extern int pnfs_alloc_init_deviceid_cache(struct nfs_client *,
 115                         void (*free_callback)(struct pnfs_deviceid_node *));
 116 extern void pnfs_put_deviceid_cache(struct nfs_client *);
 117 extern struct pnfs_deviceid_node *pnfs_find_get_deviceid(
 118                                 struct pnfs_deviceid_cache *,
 119                                 struct nfs4_deviceid *);
 120 extern struct pnfs_deviceid_node *pnfs_add_deviceid(
 121                                 struct pnfs_deviceid_cache *,
 122                                 struct pnfs_deviceid_node *);
 123 extern void pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
 124                               struct pnfs_deviceid_node *devid);
 125
 126 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 127 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 128
 129 /* nfs4proc.c */
 130 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
 131                                    struct pnfs_device *dev);
 132 extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
 133
 134 /* pnfs.c */
 135 struct pnfs_layout_segment *
 136 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 137                    enum pnfs_iomode access_type);
 138 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
 139 void unset_pnfs_layoutdriver(struct nfs_server *);
 140 int pnfs_layout_process(struct nfs4_layoutget *lgp);
 141 void pnfs_destroy_layout(struct nfs_inode *);
 142 void pnfs_destroy_all_layouts(struct nfs_client *);
 143 void put_layout_hdr(struct inode *inode);
 144 int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
 145                                   struct pnfs_layout_hdr *lo,
 146                                   struct nfs4_state *open_state);
 147
 148
 149 static inline int lo_fail_bit(u32 iomode)
 150 {
 151         return iomode == IOMODE_RW ?
 152                          NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 153 }
 154
 155 /* Return true if a layout driver is being used for this mountpoint */
 156 static inline int pnfs_enabled_sb(struct nfs_server *nfss)
 157 {
 158         return nfss->pnfs_curr_ld != NULL;
 159 }
 160
 161 #else  /* CONFIG_NFS_V4_1 */
 162
 163 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
 164 {
 165 }
 166
 167 static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
 168 {
 169 }
 170
 171 static inline struct pnfs_layout_segment *
 172 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 173                    enum pnfs_iomode access_type)
 174 {
 175         return NULL;
 176 }
 177
 178 static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
 179 {
 180 }
 181
 182 static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
 183 {
 184 }
 185
 186 #endif /* CONFIG_NFS_V4_1 */
 187
 188 #endif /* FS_NFS_PNFS_H */