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 };
  74
  75 struct pnfs_inval_tracking {
  76         struct list_head it_link;
  77         int              it_sector;
  78         int              it_tags;
  79 };
  80
  81 /* sector_t fields are all in 512-byte sectors */
  82 struct pnfs_block_extent {
  83         struct kref     be_refcnt;
  84         struct list_head be_node;       /* link into lseg list */
  85         struct nfs4_deviceid be_devid;  /* FIXME: could use device cache instead */
  86         struct block_device *be_mdev;
  87         sector_t        be_f_offset;    /* the starting offset in the file */
  88         sector_t        be_length;      /* the size of the extent */
  89         sector_t        be_v_offset;    /* the starting offset in the volume */
  90         enum exstate4   be_state;       /* the state of this extent */
  91         struct pnfs_inval_markings *be_inval; /* tracks INVAL->RW transition */
  92 };
  93
  94 /* Shortened extent used by LAYOUTCOMMIT */
  95 struct pnfs_block_short_extent {
  96         struct list_head bse_node;
  97         struct nfs4_deviceid bse_devid;
  98         struct block_device *bse_mdev;
  99         sector_t        bse_f_offset;   /* the starting offset in the file */
 100         sector_t        bse_length;     /* the size of the extent */
 101 };
 102
 103 static inline void
 104 BL_INIT_INVAL_MARKS(struct pnfs_inval_markings *marks, sector_t blocksize)
 105 {
 106         spin_lock_init(&marks->im_lock);
 107         INIT_LIST_HEAD(&marks->im_tree.mtt_stub);
 108         marks->im_block_size = blocksize;
 109         marks->im_tree.mtt_step_size = min((sector_t)PAGE_CACHE_SECTORS,
 110                                            blocksize);
 111 }
 112
 113 enum extentclass4 {
 114         RW_EXTENT       = 0, /* READWRTE and INVAL */
 115         RO_EXTENT       = 1, /* READ and NONE */
 116         EXTENT_LISTS    = 2,
 117 };
 118
 119 static inline int bl_choose_list(enum exstate4 state)
 120 {
 121         if (state == PNFS_BLOCK_READ_DATA || state == PNFS_BLOCK_NONE_DATA)
 122                 return RO_EXTENT;
 123         else
 124                 return RW_EXTENT;
 125 }
 126
 127 struct pnfs_block_layout {
 128         struct pnfs_layout_hdr bl_layout;
 129         struct pnfs_inval_markings bl_inval; /* tracks INVAL->RW transition */
 130         spinlock_t              bl_ext_lock;   /* Protects list manipulation */
 131         struct list_head        bl_extents[EXTENT_LISTS]; /* R and RW extents */
 132         struct list_head        bl_commit;      /* Needs layout commit */
 133         struct list_head        bl_committing;  /* Layout committing */
 134         unsigned int            bl_count;       /* entries in bl_commit */
 135         sector_t                bl_blocksize;  /* Server blocksize in sectors */
 136 };
 137
 138 #define BLK_ID(lo) ((struct block_mount_id *)(NFS_SERVER(lo->plh_inode)->pnfs_ld_data))
 139
 140 static inline struct pnfs_block_layout *
 141 BLK_LO2EXT(struct pnfs_layout_hdr *lo)
 142 {
 143         return container_of(lo, struct pnfs_block_layout, bl_layout);
 144 }
 145
 146 static inline struct pnfs_block_layout *
 147 BLK_LSEG2EXT(struct pnfs_layout_segment *lseg)
 148 {
 149         return BLK_LO2EXT(lseg->pls_layout);
 150 }
 151
 152 struct bl_dev_msg {
 153         int32_t status;
 154         uint32_t major, minor;
 155 };
 156
 157 struct bl_msg_hdr {
 158         u8  type;
 159         u16 totallen; /* length of entire message, including hdr itself */
 160 };
 161
 162 extern struct dentry *bl_device_pipe;
 163 extern wait_queue_head_t bl_wq;
 164
 165 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
 166 #define BL_DEVICE_MOUNT                0x1 /* Mount--create devices*/
 167 #define BL_DEVICE_REQUEST_INIT         0x0 /* Start request */
 168 #define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
 169 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
 170
 171 /* blocklayoutdev.c */
 172 ssize_t bl_pipe_downcall(struct file *, const char __user *, size_t);
 173 void bl_pipe_destroy_msg(struct rpc_pipe_msg *);
 174 struct block_device *nfs4_blkdev_get(dev_t dev);
 175 int nfs4_blkdev_put(struct block_device *bdev);
 176 struct pnfs_block_dev *nfs4_blk_decode_device(struct nfs_server *server,
 177                                                 struct pnfs_device *dev);
 178 int nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo,
 179                                 struct nfs4_layoutget_res *lgr, gfp_t gfp_flags);
 180
 181 /* blocklayoutdm.c */
 182 void bl_free_block_dev(struct pnfs_block_dev *bdev);
 183
 184 /* extents.c */
 185 struct pnfs_block_extent *
 186 bl_find_get_extent(struct pnfs_block_layout *bl, sector_t isect,
 187                 struct pnfs_block_extent **cow_read);
 188 int bl_mark_sectors_init(struct pnfs_inval_markings *marks,
 189                              sector_t offset, sector_t length,
 190                              sector_t **pages);
 191 void bl_put_extent(struct pnfs_block_extent *be);
 192 struct pnfs_block_extent *bl_alloc_extent(void);
 193 int bl_is_sector_init(struct pnfs_inval_markings *marks, sector_t isect);
 194 int encode_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
 195                                    struct xdr_stream *xdr,
 196                                    const struct nfs4_layoutcommit_args *arg);
 197 void clean_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
 198                                    const struct nfs4_layoutcommit_args *arg,
 199                                    int status);
 200 int bl_add_merge_extent(struct pnfs_block_layout *bl,
 201                          struct pnfs_block_extent *new);
 202 int bl_mark_for_commit(struct pnfs_block_extent *be,
 203                         sector_t offset, sector_t length);
 204
 205 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */