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         NFS_LSEG_ROC,           /* roc bit received from server */
  36 };
  37
  38 struct pnfs_layout_segment {
  39         struct list_head pls_list;
  40         struct pnfs_layout_range pls_range;
  41         atomic_t pls_refcount;
  42         unsigned long pls_flags;
  43         struct pnfs_layout_hdr *pls_layout;
  44 };
  45
  46 #ifdef CONFIG_NFS_V4_1
  47
  48 #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
  49
  50 enum {
  51         NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
  52         NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
  53         NFS_LAYOUT_BULK_RECALL,         /* bulk recall affecting layout */
  54         NFS_LAYOUT_ROC,                 /* some lseg had roc bit set */
  55         NFS_LAYOUT_DESTROYED,           /* no new use of layout allowed */
  56 };
  57
  58 /* Per-layout driver specific registration structure */
  59 struct pnfs_layoutdriver_type {
  60         struct list_head pnfs_tblid;
  61         const u32 id;
  62         const char *name;
  63         struct module *owner;
  64         int (*set_layoutdriver) (struct nfs_server *);
  65         int (*clear_layoutdriver) (struct nfs_server *);
  66         struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);
  67         void (*free_lseg) (struct pnfs_layout_segment *lseg);
  68 };
  69
  70 struct pnfs_layout_hdr {
  71         atomic_t                plh_refcount;
  72         struct list_head        plh_layouts;   /* other client layouts */
  73         struct list_head        plh_bulk_recall; /* clnt list of bulk recalls */
  74         struct list_head        plh_segs;      /* layout segments list */
  75         nfs4_stateid            plh_stateid;
  76         atomic_t                plh_outstanding; /* number of RPCs out */
  77         unsigned long           plh_block_lgets; /* block LAYOUTGET if >0 */
  78         u32                     plh_barrier; /* ignore lower seqids */
  79         unsigned long           plh_flags;
  80         struct inode            *plh_inode;
  81 };
  82
  83 struct pnfs_device {
  84         struct nfs4_deviceid dev_id;
  85         unsigned int  layout_type;
  86         unsigned int  mincount;
  87         struct page **pages;
  88         void          *area;
  89         unsigned int  pgbase;
  90         unsigned int  pglen;
  91 };
  92
  93 /*
  94  * Device ID RCU cache. A device ID is unique per client ID and layout type.
  95  */
  96 #define NFS4_DEVICE_ID_HASH_BITS        5
  97 #define NFS4_DEVICE_ID_HASH_SIZE        (1 << NFS4_DEVICE_ID_HASH_BITS)
  98 #define NFS4_DEVICE_ID_HASH_MASK        (NFS4_DEVICE_ID_HASH_SIZE - 1)
  99
 100 static inline u32
 101 nfs4_deviceid_hash(struct nfs4_deviceid *id)
 102 {
 103         unsigned char *cptr = (unsigned char *)id->data;
 104         unsigned int nbytes = NFS4_DEVICEID4_SIZE;
 105         u32 x = 0;
 106
 107         while (nbytes--) {
 108                 x *= 37;
 109                 x += *cptr++;
 110         }
 111         return x & NFS4_DEVICE_ID_HASH_MASK;
 112 }
 113
 114 struct pnfs_deviceid_node {
 115         struct hlist_node       de_node;
 116         struct nfs4_deviceid    de_id;
 117         atomic_t                de_ref;
 118 };
 119
 120 struct pnfs_deviceid_cache {
 121         spinlock_t              dc_lock;
 122         atomic_t                dc_ref;
 123         void                    (*dc_free_callback)(struct pnfs_deviceid_node *);
 124         struct hlist_head       dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
 125 };
 126
 127 extern int pnfs_alloc_init_deviceid_cache(struct nfs_client *,
 128                         void (*free_callback)(struct pnfs_deviceid_node *));
 129 extern void pnfs_put_deviceid_cache(struct nfs_client *);
 130 extern struct pnfs_deviceid_node *pnfs_find_get_deviceid(
 131                                 struct pnfs_deviceid_cache *,
 132                                 struct nfs4_deviceid *);
 133 extern struct pnfs_deviceid_node *pnfs_add_deviceid(
 134                                 struct pnfs_deviceid_cache *,
 135                                 struct pnfs_deviceid_node *);
 136 extern void pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
 137                               struct pnfs_deviceid_node *devid);
 138
 139 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 140 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 141
 142 /* nfs4proc.c */
 143 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
 144                                    struct pnfs_device *dev);
 145 extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
 146
 147 /* pnfs.c */
 148 void get_layout_hdr(struct pnfs_layout_hdr *lo);
 149 struct pnfs_layout_segment *
 150 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 151                    enum pnfs_iomode access_type);
 152 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
 153 void unset_pnfs_layoutdriver(struct nfs_server *);
 154 int pnfs_layout_process(struct nfs4_layoutget *lgp);
 155 void pnfs_free_lseg_list(struct list_head *tmp_list);
 156 void pnfs_destroy_layout(struct nfs_inode *);
 157 void pnfs_destroy_all_layouts(struct nfs_client *);
 158 void put_layout_hdr(struct pnfs_layout_hdr *lo);
 159 void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
 160                              const nfs4_stateid *new,
 161                              bool update_barrier);
 162 int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
 163                                   struct pnfs_layout_hdr *lo,
 164                                   struct nfs4_state *open_state);
 165 int mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 166                                 struct list_head *tmp_list,
 167                                 u32 iomode);
 168 bool pnfs_roc(struct inode *ino);
 169 void pnfs_roc_release(struct inode *ino);
 170 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
 171 bool pnfs_roc_drain(struct inode *ino, u32 *barrier);
 172
 173
 174 static inline int lo_fail_bit(u32 iomode)
 175 {
 176         return iomode == IOMODE_RW ?
 177                          NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 178 }
 179
 180 /* Return true if a layout driver is being used for this mountpoint */
 181 static inline int pnfs_enabled_sb(struct nfs_server *nfss)
 182 {
 183         return nfss->pnfs_curr_ld != NULL;
 184 }
 185
 186 #else  /* CONFIG_NFS_V4_1 */
 187
 188 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
 189 {
 190 }
 191
 192 static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
 193 {
 194 }
 195
 196 static inline struct pnfs_layout_segment *
 197 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 198                    enum pnfs_iomode access_type)
 199 {
 200         return NULL;
 201 }
 202
 203 static inline bool
 204 pnfs_roc(struct inode *ino)
 205 {
 206         return false;
 207 }
 208
 209 static inline void
 210 pnfs_roc_release(struct inode *ino)
 211 {
 212 }
 213
 214 static inline void
 215 pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
 216 {
 217 }
 218
 219 static inline bool
 220 pnfs_roc_drain(struct inode *ino, u32 *barrier)
 221 {
 222         return false;
 223 }
 224
 225 static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
 226 {
 227 }
 228
 229 static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
 230 {
 231 }
 232
 233 #endif /* CONFIG_NFS_V4_1 */
 234
 235 #endif /* FS_NFS_PNFS_H */