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_SIZE >> SECTOR_SHIFT)
  44 #define PAGE_CACHE_SECTOR_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
  45 #define SECTOR_SIZE (1 << SECTOR_SHIFT)
  46
  47 struct pnfs_block_dev;
  48
  49 #define PNFS_BLOCK_MAX_UUIDS    4
  50 #define PNFS_BLOCK_MAX_DEVICES  64
  51
  52 /*
  53  * Random upper cap for the uuid length to avoid unbounded allocation.
  54  * Not actually limited by the protocol.
  55  */
  56 #define PNFS_BLOCK_UUID_LEN     128
  57
  58 struct pnfs_block_volume {
  59         enum pnfs_block_volume_type     type;
  60         union {
  61                 struct {
  62                         int             len;
  63                         int             nr_sigs;
  64                         struct {
  65                                 u64             offset;
  66                                 u32             sig_len;
  67                                 u8              sig[PNFS_BLOCK_UUID_LEN];
  68                         } sigs[PNFS_BLOCK_MAX_UUIDS];
  69                 } simple;
  70                 struct {
  71                         u64             start;
  72                         u64             len;
  73                         u32             volume;
  74                 } slice;
  75                 struct {
  76                         u32             volumes_count;
  77                         u32             volumes[PNFS_BLOCK_MAX_DEVICES];
  78                 } concat;
  79                 struct {
  80                         u64             chunk_size;
  81                         u32             volumes_count;
  82                         u32             volumes[PNFS_BLOCK_MAX_DEVICES];
  83                 } stripe;
  84                 struct {
  85                         enum scsi_code_set              code_set;
  86                         enum scsi_designator_type       designator_type;
  87                         int                             designator_len;
  88                         u8                              designator[256];
  89                         u64                             pr_key;
  90                 } scsi;
  91         };
  92 };
  93
  94 struct pnfs_block_dev_map {
  95         sector_t                        start;
  96         sector_t                        len;
  97
  98         sector_t                        disk_offset;
  99         struct block_device             *bdev;
 100 };
 101
 102 struct pnfs_block_dev {
 103         struct nfs4_deviceid_node       node;
 104
 105         u64                             start;
 106         u64                             len;
 107
 108         u32                             nr_children;
 109         struct pnfs_block_dev           *children;
 110         u64                             chunk_size;
 111
 112         struct block_device             *bdev;
 113         u64                             disk_offset;
 114
 115         u64                             pr_key;
 116         bool                            pr_registered;
 117
 118         bool (*map)(struct pnfs_block_dev *dev, u64 offset,
 119                         struct pnfs_block_dev_map *map);
 120 };
 121
 122 /* sector_t fields are all in 512-byte sectors */
 123 struct pnfs_block_extent {
 124         union {
 125                 struct rb_node  be_node;
 126                 struct list_head be_list;
 127         };
 128         struct nfs4_deviceid_node *be_device;
 129         sector_t        be_f_offset;    /* the starting offset in the file */
 130         sector_t        be_length;      /* the size of the extent */
 131         sector_t        be_v_offset;    /* the starting offset in the volume */
 132         enum pnfs_block_extent_state be_state;  /* the state of this extent */
 133 #define EXTENT_WRITTEN          1
 134 #define EXTENT_COMMITTING       2
 135         unsigned int    be_tag;
 136 };
 137
 138 struct pnfs_block_layout {
 139         struct pnfs_layout_hdr  bl_layout;
 140         struct rb_root          bl_ext_rw;
 141         struct rb_root          bl_ext_ro;
 142         spinlock_t              bl_ext_lock;   /* Protects list manipulation */
 143         bool                    bl_scsi_layout;
 144 };
 145
 146 static inline struct pnfs_block_layout *
 147 BLK_LO2EXT(struct pnfs_layout_hdr *lo)
 148 {
 149         return container_of(lo, struct pnfs_block_layout, bl_layout);
 150 }
 151
 152 static inline struct pnfs_block_layout *
 153 BLK_LSEG2EXT(struct pnfs_layout_segment *lseg)
 154 {
 155         return BLK_LO2EXT(lseg->pls_layout);
 156 }
 157
 158 struct bl_pipe_msg {
 159         struct rpc_pipe_msg msg;
 160         wait_queue_head_t *bl_wq;
 161 };
 162
 163 struct bl_msg_hdr {
 164         u8  type;
 165         u16 totallen; /* length of entire message, including hdr itself */
 166 };
 167
 168 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
 169 #define BL_DEVICE_MOUNT                0x1 /* Mount--create devices*/
 170 #define BL_DEVICE_REQUEST_INIT         0x0 /* Start request */
 171 #define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
 172 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
 173
 174 /* dev.c */
 175 struct nfs4_deviceid_node *bl_alloc_deviceid_node(struct nfs_server *server,
 176                 struct pnfs_device *pdev, gfp_t gfp_mask);
 177 void bl_free_deviceid_node(struct nfs4_deviceid_node *d);
 178
 179 /* extent_tree.c */
 180 int ext_tree_insert(struct pnfs_block_layout *bl,
 181                 struct pnfs_block_extent *new);
 182 int ext_tree_remove(struct pnfs_block_layout *bl, bool rw, sector_t start,
 183                 sector_t end);
 184 int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
 185                 sector_t len);
 186 bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
 187                 struct pnfs_block_extent *ret, bool rw);
 188 int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg);
 189 void ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status);
 190
 191 /* rpc_pipefs.c */
 192 dev_t bl_resolve_deviceid(struct nfs_server *server,
 193                 struct pnfs_block_volume *b, gfp_t gfp_mask);
 194 int __init bl_init_pipefs(void);
 195 void bl_cleanup_pipefs(void);
 196
 197 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */