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         struct rpc_cred *pls_lc_cred; /* LAYOUTCOMMIT credential */
  47         loff_t pls_end_pos; /* LAYOUTCOMMIT write end */
  48 };
  49
  50 enum pnfs_try_status {
  51         PNFS_ATTEMPTED     = 0,
  52         PNFS_NOT_ATTEMPTED = 1,
  53 };
  54
  55 #ifdef CONFIG_NFS_V4_1
  56
  57 #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
  58
  59 enum {
  60         NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
  61         NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
  62         NFS_LAYOUT_BULK_RECALL,         /* bulk recall affecting layout */
  63         NFS_LAYOUT_ROC,                 /* some lseg had roc bit set */
  64         NFS_LAYOUT_DESTROYED,           /* no new use of layout allowed */
  65 };
  66
  67 /* Per-layout driver specific registration structure */
  68 struct pnfs_layoutdriver_type {
  69         struct list_head pnfs_tblid;
  70         const u32 id;
  71         const char *name;
  72         struct module *owner;
  73         struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr, gfp_t gfp_flags);
  74         void (*free_lseg) (struct pnfs_layout_segment *lseg);
  75
  76         /* test for nfs page cache coalescing */
  77         int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
  78
  79         /* Returns true if layoutdriver wants to divert this request to
  80          * driver's commit routine.
  81          */
  82         bool (*mark_pnfs_commit)(struct pnfs_layout_segment *lseg);
  83         struct list_head * (*choose_commit_list) (struct nfs_page *req);
  84         int (*commit_pagelist)(struct inode *inode, struct list_head *mds_pages, int how);
  85
  86         /*
  87          * Return PNFS_ATTEMPTED to indicate the layout code has attempted
  88          * I/O, else return PNFS_NOT_ATTEMPTED to fall back to normal NFS
  89          */
  90         enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data);
  91         enum pnfs_try_status (*write_pagelist) (struct nfs_write_data *nfs_data, int how);
  92 };
  93
  94 struct pnfs_layout_hdr {
  95         atomic_t                plh_refcount;
  96         struct list_head        plh_layouts;   /* other client layouts */
  97         struct list_head        plh_bulk_recall; /* clnt list of bulk recalls */
  98         struct list_head        plh_segs;      /* layout segments list */
  99         nfs4_stateid            plh_stateid;
 100         atomic_t                plh_outstanding; /* number of RPCs out */
 101         unsigned long           plh_block_lgets; /* block LAYOUTGET if >0 */
 102         u32                     plh_barrier; /* ignore lower seqids */
 103         unsigned long           plh_flags;
 104         struct inode            *plh_inode;
 105 };
 106
 107 struct pnfs_device {
 108         struct nfs4_deviceid dev_id;
 109         unsigned int  layout_type;
 110         unsigned int  mincount;
 111         struct page **pages;
 112         unsigned int  pgbase;
 113         unsigned int  pglen;
 114 };
 115
 116 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 117 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 118
 119 /* nfs4proc.c */
 120 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
 121                                    struct pnfs_device *dev);
 122 extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
 123
 124 /* pnfs.c */
 125 void get_layout_hdr(struct pnfs_layout_hdr *lo);
 126 void put_lseg(struct pnfs_layout_segment *lseg);
 127 struct pnfs_layout_segment *
 128 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 129                    enum pnfs_iomode access_type, gfp_t gfp_flags);
 130 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
 131 void unset_pnfs_layoutdriver(struct nfs_server *);
 132 enum pnfs_try_status pnfs_try_to_write_data(struct nfs_write_data *,
 133                                              const struct rpc_call_ops *, int);
 134 enum pnfs_try_status pnfs_try_to_read_data(struct nfs_read_data *,
 135                                             const struct rpc_call_ops *);
 136 void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *);
 137 void pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *);
 138 int pnfs_layout_process(struct nfs4_layoutget *lgp);
 139 void pnfs_free_lseg_list(struct list_head *tmp_list);
 140 void pnfs_destroy_layout(struct nfs_inode *);
 141 void pnfs_destroy_all_layouts(struct nfs_client *);
 142 void put_layout_hdr(struct pnfs_layout_hdr *lo);
 143 void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
 144                              const nfs4_stateid *new,
 145                              bool update_barrier);
 146 int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
 147                                   struct pnfs_layout_hdr *lo,
 148                                   struct nfs4_state *open_state);
 149 int mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 150                                 struct list_head *tmp_list,
 151                                 u32 iomode);
 152 bool pnfs_roc(struct inode *ino);
 153 void pnfs_roc_release(struct inode *ino);
 154 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
 155 bool pnfs_roc_drain(struct inode *ino, u32 *barrier);
 156 void pnfs_set_layoutcommit(struct nfs_write_data *wdata);
 157 int pnfs_layoutcommit_inode(struct inode *inode, bool sync);
 158
 159 static inline int lo_fail_bit(u32 iomode)
 160 {
 161         return iomode == IOMODE_RW ?
 162                          NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 163 }
 164
 165 static inline struct pnfs_layout_segment *
 166 get_lseg(struct pnfs_layout_segment *lseg)
 167 {
 168         if (lseg) {
 169                 atomic_inc(&lseg->pls_refcount);
 170                 smp_mb__after_atomic_inc();
 171         }
 172         return lseg;
 173 }
 174
 175 /* Return true if a layout driver is being used for this mountpoint */
 176 static inline int pnfs_enabled_sb(struct nfs_server *nfss)
 177 {
 178         return nfss->pnfs_curr_ld != NULL;
 179 }
 180
 181 static inline void
 182 pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 183 {
 184         if (lseg) {
 185                 struct pnfs_layoutdriver_type *ld;
 186
 187                 ld = NFS_SERVER(req->wb_page->mapping->host)->pnfs_curr_ld;
 188                 if (ld->mark_pnfs_commit && ld->mark_pnfs_commit(lseg)) {
 189                         set_bit(PG_PNFS_COMMIT, &req->wb_flags);
 190                         req->wb_commit_lseg = get_lseg(lseg);
 191                 }
 192         }
 193 }
 194
 195 static inline int
 196 pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how)
 197 {
 198         if (!test_and_clear_bit(NFS_INO_PNFS_COMMIT, &NFS_I(inode)->flags))
 199                 return PNFS_NOT_ATTEMPTED;
 200         return NFS_SERVER(inode)->pnfs_curr_ld->commit_pagelist(inode, mds_pages, how);
 201 }
 202
 203 static inline struct list_head *
 204 pnfs_choose_commit_list(struct nfs_page *req, struct list_head *mds)
 205 {
 206         struct list_head *rv;
 207
 208         if (test_and_clear_bit(PG_PNFS_COMMIT, &req->wb_flags)) {
 209                 struct inode *inode = req->wb_commit_lseg->pls_layout->plh_inode;
 210
 211                 set_bit(NFS_INO_PNFS_COMMIT, &NFS_I(inode)->flags);
 212                 rv = NFS_SERVER(inode)->pnfs_curr_ld->choose_commit_list(req);
 213                 /* matched by ref taken when PG_PNFS_COMMIT is set */
 214                 put_lseg(req->wb_commit_lseg);
 215         } else
 216                 rv = mds;
 217         return rv;
 218 }
 219
 220 static inline void pnfs_clear_request_commit(struct nfs_page *req)
 221 {
 222         if (test_and_clear_bit(PG_PNFS_COMMIT, &req->wb_flags))
 223                 put_lseg(req->wb_commit_lseg);
 224 }
 225
 226 #else  /* CONFIG_NFS_V4_1 */
 227
 228 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
 229 {
 230 }
 231
 232 static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
 233 {
 234 }
 235
 236 static inline struct pnfs_layout_segment *
 237 get_lseg(struct pnfs_layout_segment *lseg)
 238 {
 239         return NULL;
 240 }
 241
 242 static inline void put_lseg(struct pnfs_layout_segment *lseg)
 243 {
 244 }
 245
 246 static inline struct pnfs_layout_segment *
 247 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 248                    enum pnfs_iomode access_type, gfp_t gfp_flags)
 249 {
 250         return NULL;
 251 }
 252
 253 static inline enum pnfs_try_status
 254 pnfs_try_to_read_data(struct nfs_read_data *data,
 255                       const struct rpc_call_ops *call_ops)
 256 {
 257         return PNFS_NOT_ATTEMPTED;
 258 }
 259
 260 static inline enum pnfs_try_status
 261 pnfs_try_to_write_data(struct nfs_write_data *data,
 262                        const struct rpc_call_ops *call_ops, int how)
 263 {
 264         return PNFS_NOT_ATTEMPTED;
 265 }
 266
 267 static inline bool
 268 pnfs_roc(struct inode *ino)
 269 {
 270         return false;
 271 }
 272
 273 static inline void
 274 pnfs_roc_release(struct inode *ino)
 275 {
 276 }
 277
 278 static inline void
 279 pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
 280 {
 281 }
 282
 283 static inline bool
 284 pnfs_roc_drain(struct inode *ino, u32 *barrier)
 285 {
 286         return false;
 287 }
 288
 289 static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
 290 {
 291 }
 292
 293 static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
 294 {
 295 }
 296
 297 static inline void
 298 pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *ino)
 299 {
 300         pgio->pg_test = NULL;
 301 }
 302
 303 static inline void
 304 pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *ino)
 305 {
 306         pgio->pg_test = NULL;
 307 }
 308
 309 static inline void
 310 pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 311 {
 312 }
 313
 314 static inline int
 315 pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how)
 316 {
 317         return PNFS_NOT_ATTEMPTED;
 318 }
 319
 320 static inline struct list_head *
 321 pnfs_choose_commit_list(struct nfs_page *req, struct list_head *mds)
 322 {
 323         return mds;
 324 }
 325
 326 static inline void pnfs_clear_request_commit(struct nfs_page *req)
 327 {
 328 }
 329
 330 static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 331 {
 332         return 0;
 333 }
 334 #endif /* CONFIG_NFS_V4_1 */
 335
 336 #endif /* FS_NFS_PNFS_H */