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 upto 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
  44 enum stripetype4 {
  45         STRIPE_SPARSE = 1,
  46         STRIPE_DENSE = 2
  47 };
  48
  49 /* Individual ip address */
  50 struct 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
  61 struct nfs4_file_layout_dsaddr {
  62         struct hlist_node               node;
  63         struct nfs4_deviceid            deviceid;
  64         atomic_t                        ref;
  65         unsigned long                   flags;
  66         u32                             stripe_count;
  67         u8                              *stripe_indices;
  68         u32                             ds_num;
  69         struct nfs4_pnfs_ds             *ds_list[1];
  70 };
  71
  72 struct nfs4_filelayout_segment {
  73         struct pnfs_layout_segment generic_hdr;
  74         u32 stripe_type;
  75         u32 commit_through_mds;
  76         u32 stripe_unit;
  77         u32 first_stripe_index;
  78         u64 pattern_offset;
  79         struct nfs4_file_layout_dsaddr *dsaddr; /* Point to GETDEVINFO data */
  80         unsigned int num_fh;
  81         struct nfs_fh **fh_array;
  82 };
  83
  84 static inline struct nfs4_filelayout_segment *
  85 FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
  86 {
  87         return container_of(lseg,
  88                             struct nfs4_filelayout_segment,
  89                             generic_hdr);
  90 }
  91
  92 extern struct nfs_fh *
  93 nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j);
  94
  95 extern void print_ds(struct nfs4_pnfs_ds *ds);
  96 extern void print_deviceid(struct nfs4_deviceid *dev_id);
  97 u32 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset);
  98 u32 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j);
  99 struct nfs4_pnfs_ds *nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg,
 100                                         u32 ds_idx);
 101 extern struct nfs4_file_layout_dsaddr *
 102 nfs4_fl_find_get_deviceid(struct nfs4_deviceid *dev_id);
 103 extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 104 struct nfs4_file_layout_dsaddr *
 105 get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id);
 106
 107 #endif /* FS_NFS_NFS4FILELAYOUT_H */