fs/nfs/blocklayout/blocklayout.h

   1 /*
   2  *  linux/fs/nfs/blocklayout/blocklayout.h
   3  *
   4  *  Module for the NFSv4.1 pNFS block layout driver.
   5  *
   6  *  Copyright (c) 2006 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Andy Adamson <andros@citi.umich.edu>
  10  *  Fred Isaman <iisaman@umich.edu>
  11  *
  12  * permission is granted to use, copy, create derivative works and
  13  * redistribute this software and such derivative works for any purpose,
  14  * so long as the name of the university of michigan is not used in
  15  * any advertising or publicity pertaining to the use or distribution
  16  * of this software without specific, written prior authorization.  if
  17  * the above copyright notice or any other identification of the
  18  * university of michigan is included in any copy of any portion of
  19  * this software, then the disclaimer below must also be included.
  20  *
  21  * this software is provided as is, without representation from the
  22  * university of michigan as to its fitness for any purpose, and without
  23  * warranty by the university of michigan of any kind, either express
  24  * or implied, including without limitation the implied warranties of
  25  * merchantability and fitness for a particular purpose.  the regents
  26  * of the university of michigan shall not be liable for any damages,
  27  * including special, indirect, incidental, or consequential damages,
  28  * with respect to any claim arising out or in connection with the use
  29  * of the software, even if it has been or is hereafter advised of the
  30  * possibility of such damages.
  31  */
  32 #ifndef FS_NFS_NFS4BLOCKLAYOUT_H
  33 #define FS_NFS_NFS4BLOCKLAYOUT_H
  34
  35 #include <linux/device-mapper.h>
  36 #include <linux/nfs_fs.h>
  37 #include <linux/sunrpc/rpc_pipe_fs.h>
  38
  39 #include "../nfs4_fs.h"
  40 #include "../pnfs.h"
  41 #include "../netns.h"
  42
  43 #define PAGE_CACHE_SECTORS (PAGE_CACHE_SIZE >> SECTOR_SHIFT)
  44 #define PAGE_CACHE_SECTOR_SHIFT (PAGE_CACHE_SHIFT - SECTOR_SHIFT)
  45 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
  46
  47 struct pnfs_block_dev;
  48
  49 enum pnfs_block_volume_type {
  50         PNFS_BLOCK_VOLUME_SIMPLE        = 0,
  51         PNFS_BLOCK_VOLUME_SLICE         = 1,
  52         PNFS_BLOCK_VOLUME_CONCAT        = 2,
  53         PNFS_BLOCK_VOLUME_STRIPE        = 3,
  54 };
  55
  56 #define PNFS_BLOCK_MAX_UUIDS    4
  57 #define PNFS_BLOCK_MAX_DEVICES  64
  58
  59 /*
  60  * Random upper cap for the uuid length to avoid unbounded allocation.
  61  * Not actually limited by the protocol.
  62  */
  63 #define PNFS_BLOCK_UUID_LEN     128
  64
  65
  66 struct pnfs_block_volume {
  67         enum pnfs_block_volume_type     type;
  68         union {
  69                 struct {
  70                         int             len;
  71                         int             nr_sigs;
  72                         struct {
  73                                 u64             offset;
  74                                 u32             sig_len;
  75                                 u8              sig[PNFS_BLOCK_UUID_LEN];
  76                         } sigs[PNFS_BLOCK_MAX_UUIDS];
  77                 } simple;
  78                 struct {
  79                         u64             start;
  80                         u64             len;
  81                         u32             volume;
  82                 } slice;
  83                 struct {
  84                         u32             volumes_count;
  85                         u32             volumes[PNFS_BLOCK_MAX_DEVICES];
  86                 } concat;
  87                 struct {
  88                         u64             chunk_size;
  89                         u32             volumes_count;
  90                         u32             volumes[PNFS_BLOCK_MAX_DEVICES];
  91                 } stripe;
  92         };
  93 };
  94
  95 struct pnfs_block_dev_map {
  96         sector_t                        start;
  97         sector_t                        len;
  98
  99         sector_t                        disk_offset;
 100         struct block_device             *bdev;
 101 };
 102
 103 struct pnfs_block_dev {
 104         struct nfs4_deviceid_node       node;
 105
 106         u64                             start;
 107         u64                             len;
 108
 109         u32                             nr_children;
 110         struct pnfs_block_dev           *children;
 111         u64                             chunk_size;
 112
 113         struct block_device             *bdev;
 114         u64                             disk_offset;
 115
 116         bool (*map)(struct pnfs_block_dev *dev, u64 offset,
 117                         struct pnfs_block_dev_map *map);
 118 };
 119
 120 enum exstate4 {
 121         PNFS_BLOCK_READWRITE_DATA       = 0,
 122         PNFS_BLOCK_READ_DATA            = 1,
 123         PNFS_BLOCK_INVALID_DATA         = 2, /* mapped, but data is invalid */
 124         PNFS_BLOCK_NONE_DATA            = 3  /* unmapped, it's a hole */
 125 };
 126
 127 /* sector_t fields are all in 512-byte sectors */
 128 struct pnfs_block_extent {
 129         union {
 130                 struct rb_node  be_node;
 131                 struct list_head be_list;
 132         };
 133         struct nfs4_deviceid_node *be_device;
 134         sector_t        be_f_offset;    /* the starting offset in the file */
 135         sector_t        be_length;      /* the size of the extent */
 136         sector_t        be_v_offset;    /* the starting offset in the volume */
 137         enum exstate4   be_state;       /* the state of this extent */
 138 #define EXTENT_WRITTEN          1
 139 #define EXTENT_COMMITTING       2
 140         unsigned int    be_tag;
 141 };
 142
 143 /* on the wire size of the extent */
 144 #define BL_EXTENT_SIZE  (7 * sizeof(__be32) + NFS4_DEVICEID4_SIZE)
 145
 146 struct pnfs_block_layout {
 147         struct pnfs_layout_hdr  bl_layout;
 148         struct rb_root          bl_ext_rw;
 149         struct rb_root          bl_ext_ro;
 150         spinlock_t              bl_ext_lock;   /* Protects list manipulation */
 151 };
 152
 153 static inline struct pnfs_block_layout *
 154 BLK_LO2EXT(struct pnfs_layout_hdr *lo)
 155 {
 156         return container_of(lo, struct pnfs_block_layout, bl_layout);
 157 }
 158
 159 static inline struct pnfs_block_layout *
 160 BLK_LSEG2EXT(struct pnfs_layout_segment *lseg)
 161 {
 162         return BLK_LO2EXT(lseg->pls_layout);
 163 }
 164
 165 struct bl_pipe_msg {
 166         struct rpc_pipe_msg msg;
 167         wait_queue_head_t *bl_wq;
 168 };
 169
 170 struct bl_msg_hdr {
 171         u8  type;
 172         u16 totallen; /* length of entire message, including hdr itself */
 173 };
 174
 175 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
 176 #define BL_DEVICE_MOUNT                0x1 /* Mount--create devices*/
 177 #define BL_DEVICE_REQUEST_INIT         0x0 /* Start request */
 178 #define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
 179 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
 180
 181 /* dev.c */
 182 struct nfs4_deviceid_node *bl_alloc_deviceid_node(struct nfs_server *server,
 183                 struct pnfs_device *pdev, gfp_t gfp_mask);
 184 void bl_free_deviceid_node(struct nfs4_deviceid_node *d);
 185
 186 /* extent_tree.c */
 187 int ext_tree_insert(struct pnfs_block_layout *bl,
 188                 struct pnfs_block_extent *new);
 189 int ext_tree_remove(struct pnfs_block_layout *bl, bool rw, sector_t start,
 190                 sector_t end);
 191 int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
 192                 sector_t len);
 193 bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
 194                 struct pnfs_block_extent *ret, bool rw);
 195 int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg);
 196 void ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status);
 197
 198 /* rpc_pipefs.c */
 199 dev_t bl_resolve_deviceid(struct nfs_server *server,
 200                 struct pnfs_block_volume *b, gfp_t gfp_mask);
 201 int __init bl_init_pipefs(void);
 202 void __exit bl_cleanup_pipefs(void);
 203
 204 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */