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 #include <linux/nfs_page.h>
  34
  35 enum {
  36         NFS_LSEG_VALID = 0,     /* cleared when lseg is recalled/returned */
  37         NFS_LSEG_ROC,           /* roc bit received from server */
  38 };
  39
  40 struct pnfs_layout_segment {
  41         struct list_head pls_list;
  42         struct pnfs_layout_range pls_range;
  43         atomic_t pls_refcount;
  44         unsigned long pls_flags;
  45         struct pnfs_layout_hdr *pls_layout;
  46 };
  47
  48 enum pnfs_try_status {
  49         PNFS_ATTEMPTED     = 0,
  50         PNFS_NOT_ATTEMPTED = 1,
  51 };
  52
  53 #ifdef CONFIG_NFS_V4_1
  54
  55 #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
  56
  57 enum {
  58         NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
  59         NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
  60         NFS_LAYOUT_BULK_RECALL,         /* bulk recall affecting layout */
  61         NFS_LAYOUT_ROC,                 /* some lseg had roc bit set */
  62         NFS_LAYOUT_DESTROYED,           /* no new use of layout allowed */
  63 };
  64
  65 /* Per-layout driver specific registration structure */
  66 struct pnfs_layoutdriver_type {
  67         struct list_head pnfs_tblid;
  68         const u32 id;
  69         const char *name;
  70         struct module *owner;
  71         struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);
  72         void (*free_lseg) (struct pnfs_layout_segment *lseg);
  73
  74         /* test for nfs page cache coalescing */
  75         int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
  76
  77         /*
  78          * Return PNFS_ATTEMPTED to indicate the layout code has attempted
  79          * I/O, else return PNFS_NOT_ATTEMPTED to fall back to normal NFS
  80          */
  81         enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data);
  82 };
  83
  84 struct pnfs_layout_hdr {
  85         atomic_t                plh_refcount;
  86         struct list_head        plh_layouts;   /* other client layouts */
  87         struct list_head        plh_bulk_recall; /* clnt list of bulk recalls */
  88         struct list_head        plh_segs;      /* layout segments list */
  89         nfs4_stateid            plh_stateid;
  90         atomic_t                plh_outstanding; /* number of RPCs out */
  91         unsigned long           plh_block_lgets; /* block LAYOUTGET if >0 */
  92         u32                     plh_barrier; /* ignore lower seqids */
  93         unsigned long           plh_flags;
  94         struct inode            *plh_inode;
  95 };
  96
  97 struct pnfs_device {
  98         struct nfs4_deviceid dev_id;
  99         unsigned int  layout_type;
 100         unsigned int  mincount;
 101         struct page **pages;
 102         void          *area;
 103         unsigned int  pgbase;
 104         unsigned int  pglen;
 105 };
 106
 107 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 108 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 109
 110 /* nfs4proc.c */
 111 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
 112                                    struct pnfs_device *dev);
 113 extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
 114
 115 /* pnfs.c */
 116 void get_layout_hdr(struct pnfs_layout_hdr *lo);
 117 void put_lseg(struct pnfs_layout_segment *lseg);
 118 struct pnfs_layout_segment *
 119 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 120                    enum pnfs_iomode access_type);
 121 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
 122 void unset_pnfs_layoutdriver(struct nfs_server *);
 123 enum pnfs_try_status pnfs_try_to_read_data(struct nfs_read_data *,
 124                                             const struct rpc_call_ops *);
 125 void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *);
 126 void pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *);
 127 int pnfs_layout_process(struct nfs4_layoutget *lgp);
 128 void pnfs_free_lseg_list(struct list_head *tmp_list);
 129 void pnfs_destroy_layout(struct nfs_inode *);
 130 void pnfs_destroy_all_layouts(struct nfs_client *);
 131 void put_layout_hdr(struct pnfs_layout_hdr *lo);
 132 void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
 133                              const nfs4_stateid *new,
 134                              bool update_barrier);
 135 int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
 136                                   struct pnfs_layout_hdr *lo,
 137                                   struct nfs4_state *open_state);
 138 int mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 139                                 struct list_head *tmp_list,
 140                                 u32 iomode);
 141 bool pnfs_roc(struct inode *ino);
 142 void pnfs_roc_release(struct inode *ino);
 143 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
 144 bool pnfs_roc_drain(struct inode *ino, u32 *barrier);
 145
 146
 147 static inline int lo_fail_bit(u32 iomode)
 148 {
 149         return iomode == IOMODE_RW ?
 150                          NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 151 }
 152
 153 static inline struct pnfs_layout_segment *
 154 get_lseg(struct pnfs_layout_segment *lseg)
 155 {
 156         if (lseg) {
 157                 atomic_inc(&lseg->pls_refcount);
 158                 smp_mb__after_atomic_inc();
 159         }
 160         return lseg;
 161 }
 162
 163 /* Return true if a layout driver is being used for this mountpoint */
 164 static inline int pnfs_enabled_sb(struct nfs_server *nfss)
 165 {
 166         return nfss->pnfs_curr_ld != NULL;
 167 }
 168
 169 #else  /* CONFIG_NFS_V4_1 */
 170
 171 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
 172 {
 173 }
 174
 175 static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
 176 {
 177 }
 178
 179 static inline struct pnfs_layout_segment *
 180 get_lseg(struct pnfs_layout_segment *lseg)
 181 {
 182         return NULL;
 183 }
 184
 185 static inline void put_lseg(struct pnfs_layout_segment *lseg)
 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 enum pnfs_try_status
 197 pnfs_try_to_read_data(struct nfs_read_data *data,
 198                       const struct rpc_call_ops *call_ops)
 199 {
 200         return PNFS_NOT_ATTEMPTED;
 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 static inline void
 234 pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *ino)
 235 {
 236         pgio->pg_test = NULL;
 237 }
 238
 239 static inline void
 240 pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *ino)
 241 {
 242         pgio->pg_test = NULL;
 243 }
 244
 245 #endif /* CONFIG_NFS_V4_1 */
 246
 247 #endif /* FS_NFS_PNFS_H */