LXR linux/fs/nfs/nfs4filelayout.h

   1/*
   2 *  NFSv4 file layout driver 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_NFS4FILELAYOUT_H
  31#define FS_NFS_NFS4FILELAYOUT_H
  32
  33#include "pnfs.h"
  34
  35/*
  36 * Field testing shows we need to support up to 4096 stripe indices.
  37 * We store each index as a u8 (u32 on the wire) to keep the memory footprint
  38 * reasonable. This in turn means we support a maximum of 256
  39 * RFC 5661 multipath_list4 structures.
  40 */
  41#define NFS4_PNFS_MAX_STRIPE_CNT 4096
  42#define NFS4_PNFS_MAX_MULTI_CNT  256 /* 256 fit into a u8 stripe_index */
  43
  44enum stripetype4 {
  45        STRIPE_SPARSE = 1,
  46        STRIPE_DENSE = 2
  47};
  48
  49/* Individual ip address */
  50struct nfs4_pnfs_ds {
  51        struct list_head        ds_node;  /* nfs4_pnfs_dev_hlist dev_dslist */
  52        u32                     ds_ip_addr;
  53        u32                     ds_port;
  54        struct nfs_client       *ds_clp;
  55        atomic_t                ds_count;
  56};
  57
  58/* nfs4_file_layout_dsaddr flags */
  59#define NFS4_DEVICE_ID_NEG_ENTRY        0x00000001
  60
  61struct nfs4_file_layout_dsaddr {
  62        struct nfs4_deviceid_node       id_node;
  63        unsigned long                   flags;
  64        u32                             stripe_count;
  65        u8                              *stripe_indices;
  66        u32                             ds_num;
  67        struct nfs4_pnfs_ds             *ds_list[1];
  68};
  69
  70struct nfs4_filelayout_segment {
  71        struct pnfs_layout_segment generic_hdr;
  72        u32 stripe_type;
  73        u32 commit_through_mds;
  74        u32 stripe_unit;
  75        u32 first_stripe_index;
  76        u64 pattern_offset;
  77        struct nfs4_file_layout_dsaddr *dsaddr; /* Point to GETDEVINFO data */
  78        unsigned int num_fh;
  79        struct nfs_fh **fh_array;
  80        struct list_head *commit_buckets; /* Sort commits to ds */
  81        int number_of_buckets;
  82};
  83
  84static inline struct nfs4_filelayout_segment *
  85FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
  86{
  87        return container_of(lseg,
  88                            struct nfs4_filelayout_segment,
  89                            generic_hdr);
  90}
  91
  92extern struct nfs_fh *
  93nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j);
  94
  95extern void print_ds(struct nfs4_pnfs_ds *ds);
  96u32 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset);
  97u32 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j);
  98struct nfs4_pnfs_ds *nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg,
  99                                        u32 ds_idx);
 100extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 101extern void nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 102struct nfs4_file_layout_dsaddr *
 103get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id, gfp_t gfp_flags);
 104
 105#endif /* FS_NFS_NFS4FILELAYOUT_H */
 106