fs/nfs/pnfs.h

   1 /*
   2  *  pNFS client 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_PNFS_H
  31 #define FS_NFS_PNFS_H
  32
  33 enum {
  34         NFS_LSEG_VALID = 0,     /* cleared when lseg is recalled/returned */
  35 };
  36
  37 struct pnfs_layout_segment {
  38         struct list_head pls_list;
  39         struct pnfs_layout_range pls_range;
  40         atomic_t pls_refcount;
  41         unsigned long pls_flags;
  42         struct pnfs_layout_hdr *pls_layout;
  43 };
  44
  45 #ifdef CONFIG_NFS_V4_1
  46
  47 #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
  48
  49 enum {
  50         NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
  51         NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
  52         NFS_LAYOUT_BULK_RECALL,         /* bulk recall affecting layout */
  53         NFS_LAYOUT_DESTROYED,           /* no new use of layout allowed */
  54 };
  55
  56 /* Per-layout driver specific registration structure */
  57 struct pnfs_layoutdriver_type {
  58         struct list_head pnfs_tblid;
  59         const u32 id;
  60         const char *name;
  61         struct module *owner;
  62         int (*set_layoutdriver) (struct nfs_server *);
  63         int (*clear_layoutdriver) (struct nfs_server *);
  64         struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);
  65         void (*free_lseg) (struct pnfs_layout_segment *lseg);
  66 };
  67
  68 struct pnfs_layout_hdr {
  69         atomic_t                plh_refcount;
  70         struct list_head        plh_layouts;   /* other client layouts */
  71         struct list_head        plh_bulk_recall; /* clnt list of bulk recalls */
  72         struct list_head        plh_segs;      /* layout segments list */
  73         nfs4_stateid            plh_stateid;
  74         atomic_t                plh_outstanding; /* number of RPCs out */
  75         u32                     plh_barrier; /* ignore lower seqids */
  76         unsigned long           plh_flags;
  77         struct inode            *plh_inode;
  78 };
  79
  80 struct pnfs_device {
  81         struct nfs4_deviceid dev_id;
  82         unsigned int  layout_type;
  83         unsigned int  mincount;
  84         struct page **pages;
  85         void          *area;
  86         unsigned int  pgbase;
  87         unsigned int  pglen;
  88 };
  89
  90 /*
  91  * Device ID RCU cache. A device ID is unique per client ID and layout type.
  92  */
  93 #define NFS4_DEVICE_ID_HASH_BITS        5
  94 #define NFS4_DEVICE_ID_HASH_SIZE        (1 << NFS4_DEVICE_ID_HASH_BITS)
  95 #define NFS4_DEVICE_ID_HASH_MASK        (NFS4_DEVICE_ID_HASH_SIZE - 1)
  96
  97 static inline u32
  98 nfs4_deviceid_hash(struct nfs4_deviceid *id)
  99 {
 100         unsigned char *cptr = (unsigned char *)id->data;
 101         unsigned int nbytes = NFS4_DEVICEID4_SIZE;
 102         u32 x = 0;
 103
 104         while (nbytes--) {
 105                 x *= 37;
 106                 x += *cptr++;
 107         }
 108         return x & NFS4_DEVICE_ID_HASH_MASK;
 109 }
 110
 111 struct pnfs_deviceid_node {
 112         struct hlist_node       de_node;
 113         struct nfs4_deviceid    de_id;
 114         atomic_t                de_ref;
 115 };
 116
 117 struct pnfs_deviceid_cache {
 118         spinlock_t              dc_lock;
 119         atomic_t                dc_ref;
 120         void                    (*dc_free_callback)(struct pnfs_deviceid_node *);
 121         struct hlist_head       dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
 122 };
 123
 124 extern int pnfs_alloc_init_deviceid_cache(struct nfs_client *,
 125                         void (*free_callback)(struct pnfs_deviceid_node *));
 126 extern void pnfs_put_deviceid_cache(struct nfs_client *);
 127 extern struct pnfs_deviceid_node *pnfs_find_get_deviceid(
 128                                 struct pnfs_deviceid_cache *,
 129                                 struct nfs4_deviceid *);
 130 extern struct pnfs_deviceid_node *pnfs_add_deviceid(
 131                                 struct pnfs_deviceid_cache *,
 132                                 struct pnfs_deviceid_node *);
 133 extern void pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
 134                               struct pnfs_deviceid_node *devid);
 135
 136 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 137 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 138
 139 /* nfs4proc.c */
 140 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
 141                                    struct pnfs_device *dev);
 142 extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
 143
 144 /* pnfs.c */
 145 void get_layout_hdr(struct pnfs_layout_hdr *lo);
 146 struct pnfs_layout_segment *
 147 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 148                    enum pnfs_iomode access_type);
 149 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
 150 void unset_pnfs_layoutdriver(struct nfs_server *);
 151 int pnfs_layout_process(struct nfs4_layoutget *lgp);
 152 void pnfs_free_lseg_list(struct list_head *tmp_list);
 153 void pnfs_destroy_layout(struct nfs_inode *);
 154 void pnfs_destroy_all_layouts(struct nfs_client *);
 155 void put_layout_hdr(struct pnfs_layout_hdr *lo);
 156 void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
 157                              const nfs4_stateid *new,
 158                              bool update_barrier);
 159 int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
 160                                   struct pnfs_layout_hdr *lo,
 161                                   struct nfs4_state *open_state);
 162 int mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 163                                 struct list_head *tmp_list,
 164                                 u32 iomode);
 165
 166
 167 static inline int lo_fail_bit(u32 iomode)
 168 {
 169         return iomode == IOMODE_RW ?
 170                          NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 171 }
 172
 173 /* Return true if a layout driver is being used for this mountpoint */
 174 static inline int pnfs_enabled_sb(struct nfs_server *nfss)
 175 {
 176         return nfss->pnfs_curr_ld != NULL;
 177 }
 178
 179 #else  /* CONFIG_NFS_V4_1 */
 180
 181 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
 182 {
 183 }
 184
 185 static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
 186 {
 187 }
 188
 189 static inline struct pnfs_layout_segment *
 190 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 191                    enum pnfs_iomode access_type)
 192 {
 193         return NULL;
 194 }
 195
 196 static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
 197 {
 198 }
 199
 200 static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
 201 {
 202 }
 203
 204 #endif /* CONFIG_NFS_V4_1 */
 205
 206 #endif /* FS_NFS_PNFS_H */