LXR linux/fs/nfs/filelayout/filelayout.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
  49struct nfs4_file_layout_dsaddr {
  50        struct nfs4_deviceid_node       id_node;
  51        u32                             stripe_count;
  52        u8                              *stripe_indices;
  53        u32                             ds_num;
  54        struct nfs4_pnfs_ds             *ds_list[1];
  55};
  56
  57struct nfs4_filelayout_segment {
  58        struct pnfs_layout_segment      generic_hdr;
  59        u32                             stripe_type;
  60        u32                             commit_through_mds;
  61        u32                             stripe_unit;
  62        u32                             first_stripe_index;
  63        u64                             pattern_offset;
  64        struct nfs4_deviceid            deviceid;
  65        struct nfs4_file_layout_dsaddr  *dsaddr; /* Point to GETDEVINFO data */
  66        unsigned int                    num_fh;
  67        struct nfs_fh                   **fh_array;
  68};
  69
  70struct nfs4_filelayout {
  71        struct pnfs_layout_hdr generic_hdr;
  72        struct pnfs_ds_commit_info commit_info;
  73};
  74
  75static inline struct nfs4_filelayout *
  76FILELAYOUT_FROM_HDR(struct pnfs_layout_hdr *lo)
  77{
  78        return container_of(lo, struct nfs4_filelayout, generic_hdr);
  79}
  80
  81static inline struct nfs4_filelayout_segment *
  82FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
  83{
  84        return container_of(lseg,
  85                            struct nfs4_filelayout_segment,
  86                            generic_hdr);
  87}
  88
  89static inline struct nfs4_deviceid_node *
  90FILELAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg)
  91{
  92        return &FILELAYOUT_LSEG(lseg)->dsaddr->id_node;
  93}
  94
  95static inline bool
  96filelayout_test_devid_invalid(struct nfs4_deviceid_node *node)
  97{
  98        return test_bit(NFS_DEVICEID_INVALID, &node->flags);
  99}
 100
 101extern bool
 102filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node);
 103
 104extern struct nfs_fh *
 105nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j);
 106
 107u32 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset);
 108u32 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j);
 109struct nfs4_pnfs_ds *nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg,
 110                                        u32 ds_idx);
 111
 112extern struct nfs4_file_layout_dsaddr *
 113nfs4_fl_alloc_deviceid_node(struct nfs_server *server,
 114        struct pnfs_device *pdev, gfp_t gfp_flags);
 115extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 116extern void nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 117
 118#endif /* FS_NFS_NFS4FILELAYOUT_H */
 119