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 "../pnfs.h"
  40
  41 #define PAGE_CACHE_SECTORS (PAGE_CACHE_SIZE >> SECTOR_SHIFT)
  42 #define PAGE_CACHE_SECTOR_SHIFT (PAGE_CACHE_SHIFT - SECTOR_SHIFT)
  43
  44 struct block_mount_id {
  45         spinlock_t                      bm_lock;    /* protects list */
  46         struct list_head                bm_devlist; /* holds pnfs_block_dev */
  47 };
  48
  49 struct pnfs_block_dev {
  50         struct list_head                bm_node;
  51         struct nfs4_deviceid            bm_mdevid;    /* associated devid */
  52         struct block_device             *bm_mdev;     /* meta device itself */
  53 };
  54
  55 enum exstate4 {
  56         PNFS_BLOCK_READWRITE_DATA       = 0,
  57         PNFS_BLOCK_READ_DATA            = 1,
  58         PNFS_BLOCK_INVALID_DATA         = 2, /* mapped, but data is invalid */
  59         PNFS_BLOCK_NONE_DATA            = 3  /* unmapped, it's a hole */
  60 };
  61
  62 #define MY_MAX_TAGS (15) /* tag bitnums used must be less than this */
  63
  64 struct my_tree {
  65         sector_t                mtt_step_size;  /* Internal sector alignment */
  66         struct list_head        mtt_stub; /* Should be a radix tree */
  67 };
  68
  69 struct pnfs_inval_markings {
  70         spinlock_t      im_lock;
  71         struct my_tree  im_tree;        /* Sectors that need LAYOUTCOMMIT */
  72         sector_t        im_block_size;  /* Server blocksize in sectors */
  73         struct list_head im_extents;    /* Short extents for INVAL->RW conversion */
  74 };
  75
  76 struct pnfs_inval_tracking {
  77         struct list_head it_link;
  78         int              it_sector;
  79         int              it_tags;
  80 };
  81
  82 /* sector_t fields are all in 512-byte sectors */
  83 struct pnfs_block_extent {
  84         struct kref     be_refcnt;
  85         struct list_head be_node;       /* link into lseg list */
  86         struct nfs4_deviceid be_devid;  /* FIXME: could use device cache instead */
  87         struct block_device *be_mdev;
  88         sector_t        be_f_offset;    /* the starting offset in the file */
  89         sector_t        be_length;      /* the size of the extent */
  90         sector_t        be_v_offset;    /* the starting offset in the volume */
  91         enum exstate4   be_state;       /* the state of this extent */
  92         struct pnfs_inval_markings *be_inval; /* tracks INVAL->RW transition */
  93 };
  94
  95 /* Shortened extent used by LAYOUTCOMMIT */
  96 struct pnfs_block_short_extent {
  97         struct list_head bse_node;
  98         struct nfs4_deviceid bse_devid;
  99         struct block_device *bse_mdev;
 100         sector_t        bse_f_offset;   /* the starting offset in the file */
 101         sector_t        bse_length;     /* the size of the extent */
 102 };
 103
 104 static inline void
 105 BL_INIT_INVAL_MARKS(struct pnfs_inval_markings *marks, sector_t blocksize)
 106 {
 107         spin_lock_init(&marks->im_lock);
 108         INIT_LIST_HEAD(&marks->im_tree.mtt_stub);
 109         INIT_LIST_HEAD(&marks->im_extents);
 110         marks->im_block_size = blocksize;
 111         marks->im_tree.mtt_step_size = min((sector_t)PAGE_CACHE_SECTORS,
 112                                            blocksize);
 113 }
 114
 115 enum extentclass4 {
 116         RW_EXTENT       = 0, /* READWRTE and INVAL */
 117         RO_EXTENT       = 1, /* READ and NONE */
 118         EXTENT_LISTS    = 2,
 119 };
 120
 121 static inline int bl_choose_list(enum exstate4 state)
 122 {
 123         if (state == PNFS_BLOCK_READ_DATA || state == PNFS_BLOCK_NONE_DATA)
 124                 return RO_EXTENT;
 125         else
 126                 return RW_EXTENT;
 127 }
 128
 129 struct pnfs_block_layout {
 130         struct pnfs_layout_hdr bl_layout;
 131         struct pnfs_inval_markings bl_inval; /* tracks INVAL->RW transition */
 132         spinlock_t              bl_ext_lock;   /* Protects list manipulation */
 133         struct list_head        bl_extents[EXTENT_LISTS]; /* R and RW extents */
 134         struct list_head        bl_commit;      /* Needs layout commit */
 135         struct list_head        bl_committing;  /* Layout committing */
 136         unsigned int            bl_count;       /* entries in bl_commit */
 137         sector_t                bl_blocksize;  /* Server blocksize in sectors */
 138 };
 139
 140 #define BLK_ID(lo) ((struct block_mount_id *)(NFS_SERVER(lo->plh_inode)->pnfs_ld_data))
 141
 142 static inline struct pnfs_block_layout *
 143 BLK_LO2EXT(struct pnfs_layout_hdr *lo)
 144 {
 145         return container_of(lo, struct pnfs_block_layout, bl_layout);
 146 }
 147
 148 static inline struct pnfs_block_layout *
 149 BLK_LSEG2EXT(struct pnfs_layout_segment *lseg)
 150 {
 151         return BLK_LO2EXT(lseg->pls_layout);
 152 }
 153
 154 struct bl_dev_msg {
 155         int32_t status;
 156         uint32_t major, minor;
 157 };
 158
 159 struct bl_msg_hdr {
 160         u8  type;
 161         u16 totallen; /* length of entire message, including hdr itself */
 162 };
 163
 164 extern struct dentry *bl_device_pipe;
 165 extern wait_queue_head_t bl_wq;
 166
 167 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
 168 #define BL_DEVICE_MOUNT                0x1 /* Mount--create devices*/
 169 #define BL_DEVICE_REQUEST_INIT         0x0 /* Start request */
 170 #define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
 171 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
 172
 173 /* blocklayoutdev.c */
 174 ssize_t bl_pipe_downcall(struct file *, const char __user *, size_t);
 175 void bl_pipe_destroy_msg(struct rpc_pipe_msg *);
 176 struct block_device *nfs4_blkdev_get(dev_t dev);
 177 int nfs4_blkdev_put(struct block_device *bdev);
 178 struct pnfs_block_dev *nfs4_blk_decode_device(struct nfs_server *server,
 179                                                 struct pnfs_device *dev);
 180 int nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo,
 181                                 struct nfs4_layoutget_res *lgr, gfp_t gfp_flags);
 182
 183 /* blocklayoutdm.c */
 184 void bl_free_block_dev(struct pnfs_block_dev *bdev);
 185
 186 /* extents.c */
 187 struct pnfs_block_extent *
 188 bl_find_get_extent(struct pnfs_block_layout *bl, sector_t isect,
 189                 struct pnfs_block_extent **cow_read);
 190 int bl_mark_sectors_init(struct pnfs_inval_markings *marks,
 191                              sector_t offset, sector_t length);
 192 void bl_put_extent(struct pnfs_block_extent *be);
 193 struct pnfs_block_extent *bl_alloc_extent(void);
 194 int bl_is_sector_init(struct pnfs_inval_markings *marks, sector_t isect);
 195 int encode_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
 196                                    struct xdr_stream *xdr,
 197                                    const struct nfs4_layoutcommit_args *arg);
 198 void clean_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
 199                                    const struct nfs4_layoutcommit_args *arg,
 200                                    int status);
 201 int bl_add_merge_extent(struct pnfs_block_layout *bl,
 202                          struct pnfs_block_extent *new);
 203 int bl_mark_for_commit(struct pnfs_block_extent *be,
 204                         sector_t offset, sector_t length,
 205                         struct pnfs_block_short_extent *new);
 206 int bl_push_one_short_extent(struct pnfs_inval_markings *marks);
 207 struct pnfs_block_short_extent *
 208 bl_pop_one_short_extent(struct pnfs_inval_markings *marks);
 209 void bl_free_short_extents(struct pnfs_inval_markings *marks, int num_to_free);
 210
 211 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */