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_fs.h>
  34 #include <linux/nfs_page.h>
  35
  36 enum {
  37         NFS_LSEG_VALID = 0,     /* cleared when lseg is recalled/returned */
  38         NFS_LSEG_ROC,           /* roc bit received from server */
  39 };
  40
  41 struct pnfs_layout_segment {
  42         struct list_head pls_list;
  43         struct pnfs_layout_range pls_range;
  44         atomic_t pls_refcount;
  45         unsigned long pls_flags;
  46         struct pnfs_layout_hdr *pls_layout;
  47         struct rpc_cred *pls_lc_cred; /* LAYOUTCOMMIT credential */
  48         loff_t pls_end_pos; /* LAYOUTCOMMIT write end */
  49 };
  50
  51 enum pnfs_try_status {
  52         PNFS_ATTEMPTED     = 0,
  53         PNFS_NOT_ATTEMPTED = 1,
  54 };
  55
  56 #ifdef CONFIG_NFS_V4_1
  57
  58 #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
  59
  60 enum {
  61         NFS_LAYOUT_RO_FAILED = 0,       /* get ro layout failed stop trying */
  62         NFS_LAYOUT_RW_FAILED,           /* get rw layout failed stop trying */
  63         NFS_LAYOUT_BULK_RECALL,         /* bulk recall affecting layout */
  64         NFS_LAYOUT_ROC,                 /* some lseg had roc bit set */
  65         NFS_LAYOUT_DESTROYED,           /* no new use of layout allowed */
  66 };
  67
  68 struct nfs4_deviceid_node;
  69
  70 /* Per-layout driver specific registration structure */
  71 struct pnfs_layoutdriver_type {
  72         struct list_head pnfs_tblid;
  73         const u32 id;
  74         const char *name;
  75         struct module *owner;
  76         struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr, gfp_t gfp_flags);
  77         void (*free_lseg) (struct pnfs_layout_segment *lseg);
  78
  79         /* test for nfs page cache coalescing */
  80         int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
  81
  82         /* Returns true if layoutdriver wants to divert this request to
  83          * driver's commit routine.
  84          */
  85         bool (*mark_pnfs_commit)(struct pnfs_layout_segment *lseg);
  86         struct list_head * (*choose_commit_list) (struct nfs_page *req);
  87         int (*commit_pagelist)(struct inode *inode, struct list_head *mds_pages, int how);
  88
  89         /*
  90          * Return PNFS_ATTEMPTED to indicate the layout code has attempted
  91          * I/O, else return PNFS_NOT_ATTEMPTED to fall back to normal NFS
  92          */
  93         enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data);
  94         enum pnfs_try_status (*write_pagelist) (struct nfs_write_data *nfs_data, int how);
  95
  96         void (*free_deviceid_node) (struct nfs4_deviceid_node *);
  97 };
  98
  99 struct pnfs_layout_hdr {
 100         atomic_t                plh_refcount;
 101         struct list_head        plh_layouts;   /* other client layouts */
 102         struct list_head        plh_bulk_recall; /* clnt list of bulk recalls */
 103         struct list_head        plh_segs;      /* layout segments list */
 104         nfs4_stateid            plh_stateid;
 105         atomic_t                plh_outstanding; /* number of RPCs out */
 106         unsigned long           plh_block_lgets; /* block LAYOUTGET if >0 */
 107         u32                     plh_barrier; /* ignore lower seqids */
 108         unsigned long           plh_flags;
 109         struct inode            *plh_inode;
 110 };
 111
 112 struct pnfs_device {
 113         struct nfs4_deviceid dev_id;
 114         unsigned int  layout_type;
 115         unsigned int  mincount;
 116         struct page **pages;
 117         unsigned int  pgbase;
 118         unsigned int  pglen;
 119 };
 120
 121 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 122 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 123
 124 /* nfs4proc.c */
 125 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
 126                                    struct pnfs_device *dev);
 127 extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
 128
 129 /* pnfs.c */
 130 void get_layout_hdr(struct pnfs_layout_hdr *lo);
 131 void put_lseg(struct pnfs_layout_segment *lseg);
 132 struct pnfs_layout_segment *
 133 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 134                    loff_t pos, u64 count, enum pnfs_iomode access_type,
 135                    gfp_t gfp_flags);
 136 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
 137 void unset_pnfs_layoutdriver(struct nfs_server *);
 138 enum pnfs_try_status pnfs_try_to_write_data(struct nfs_write_data *,
 139                                              const struct rpc_call_ops *, int);
 140 enum pnfs_try_status pnfs_try_to_read_data(struct nfs_read_data *,
 141                                             const struct rpc_call_ops *);
 142 void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *);
 143 void pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *);
 144 int pnfs_layout_process(struct nfs4_layoutget *lgp);
 145 void pnfs_free_lseg_list(struct list_head *tmp_list);
 146 void pnfs_destroy_layout(struct nfs_inode *);
 147 void pnfs_destroy_all_layouts(struct nfs_client *);
 148 void put_layout_hdr(struct pnfs_layout_hdr *lo);
 149 void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
 150                              const nfs4_stateid *new,
 151                              bool update_barrier);
 152 int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
 153                                   struct pnfs_layout_hdr *lo,
 154                                   struct nfs4_state *open_state);
 155 int mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 156                                 struct list_head *tmp_list,
 157                                 u32 iomode);
 158 bool pnfs_roc(struct inode *ino);
 159 void pnfs_roc_release(struct inode *ino);
 160 void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
 161 bool pnfs_roc_drain(struct inode *ino, u32 *barrier);
 162 void pnfs_set_layoutcommit(struct nfs_write_data *wdata);
 163 int pnfs_layoutcommit_inode(struct inode *inode, bool sync);
 164
 165 /* pnfs_dev.c */
 166 struct nfs4_deviceid_node {
 167         struct hlist_node               node;
 168         const struct pnfs_layoutdriver_type *ld;
 169         const struct nfs_client         *nfs_client;
 170         struct nfs4_deviceid            deviceid;
 171         atomic_t                        ref;
 172 };
 173
 174 void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id);
 175 struct nfs4_deviceid_node *nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
 176 struct nfs4_deviceid_node *nfs4_unhash_put_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
 177 void nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
 178 void nfs4_init_deviceid_node(struct nfs4_deviceid_node *,
 179                              const struct pnfs_layoutdriver_type *,
 180                              const struct nfs_client *,
 181                              const struct nfs4_deviceid *);
 182 struct nfs4_deviceid_node *nfs4_insert_deviceid_node(struct nfs4_deviceid_node *);
 183 bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
 184 void nfs4_deviceid_purge_client(const struct nfs_client *);
 185
 186 static inline int lo_fail_bit(u32 iomode)
 187 {
 188         return iomode == IOMODE_RW ?
 189                          NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 190 }
 191
 192 static inline struct pnfs_layout_segment *
 193 get_lseg(struct pnfs_layout_segment *lseg)
 194 {
 195         if (lseg) {
 196                 atomic_inc(&lseg->pls_refcount);
 197                 smp_mb__after_atomic_inc();
 198         }
 199         return lseg;
 200 }
 201
 202 /* Return true if a layout driver is being used for this mountpoint */
 203 static inline int pnfs_enabled_sb(struct nfs_server *nfss)
 204 {
 205         return nfss->pnfs_curr_ld != NULL;
 206 }
 207
 208 static inline void
 209 pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 210 {
 211         if (lseg) {
 212                 struct pnfs_layoutdriver_type *ld;
 213
 214                 ld = NFS_SERVER(req->wb_page->mapping->host)->pnfs_curr_ld;
 215                 if (ld->mark_pnfs_commit && ld->mark_pnfs_commit(lseg)) {
 216                         set_bit(PG_PNFS_COMMIT, &req->wb_flags);
 217                         req->wb_commit_lseg = get_lseg(lseg);
 218                 }
 219         }
 220 }
 221
 222 static inline int
 223 pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how)
 224 {
 225         if (!test_and_clear_bit(NFS_INO_PNFS_COMMIT, &NFS_I(inode)->flags))
 226                 return PNFS_NOT_ATTEMPTED;
 227         return NFS_SERVER(inode)->pnfs_curr_ld->commit_pagelist(inode, mds_pages, how);
 228 }
 229
 230 static inline struct list_head *
 231 pnfs_choose_commit_list(struct nfs_page *req, struct list_head *mds)
 232 {
 233         struct list_head *rv;
 234
 235         if (test_and_clear_bit(PG_PNFS_COMMIT, &req->wb_flags)) {
 236                 struct inode *inode = req->wb_commit_lseg->pls_layout->plh_inode;
 237
 238                 set_bit(NFS_INO_PNFS_COMMIT, &NFS_I(inode)->flags);
 239                 rv = NFS_SERVER(inode)->pnfs_curr_ld->choose_commit_list(req);
 240                 /* matched by ref taken when PG_PNFS_COMMIT is set */
 241                 put_lseg(req->wb_commit_lseg);
 242         } else
 243                 rv = mds;
 244         return rv;
 245 }
 246
 247 static inline void pnfs_clear_request_commit(struct nfs_page *req)
 248 {
 249         if (test_and_clear_bit(PG_PNFS_COMMIT, &req->wb_flags))
 250                 put_lseg(req->wb_commit_lseg);
 251 }
 252
 253 #else  /* CONFIG_NFS_V4_1 */
 254
 255 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
 256 {
 257 }
 258
 259 static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
 260 {
 261 }
 262
 263 static inline struct pnfs_layout_segment *
 264 get_lseg(struct pnfs_layout_segment *lseg)
 265 {
 266         return NULL;
 267 }
 268
 269 static inline void put_lseg(struct pnfs_layout_segment *lseg)
 270 {
 271 }
 272
 273 static inline struct pnfs_layout_segment *
 274 pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
 275                    loff_t pos, u64 count, enum pnfs_iomode access_type,
 276                    gfp_t gfp_flags)
 277 {
 278         return NULL;
 279 }
 280
 281 static inline enum pnfs_try_status
 282 pnfs_try_to_read_data(struct nfs_read_data *data,
 283                       const struct rpc_call_ops *call_ops)
 284 {
 285         return PNFS_NOT_ATTEMPTED;
 286 }
 287
 288 static inline enum pnfs_try_status
 289 pnfs_try_to_write_data(struct nfs_write_data *data,
 290                        const struct rpc_call_ops *call_ops, int how)
 291 {
 292         return PNFS_NOT_ATTEMPTED;
 293 }
 294
 295 static inline bool
 296 pnfs_roc(struct inode *ino)
 297 {
 298         return false;
 299 }
 300
 301 static inline void
 302 pnfs_roc_release(struct inode *ino)
 303 {
 304 }
 305
 306 static inline void
 307 pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
 308 {
 309 }
 310
 311 static inline bool
 312 pnfs_roc_drain(struct inode *ino, u32 *barrier)
 313 {
 314         return false;
 315 }
 316
 317 static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
 318 {
 319 }
 320
 321 static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
 322 {
 323 }
 324
 325 static inline void
 326 pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *ino)
 327 {
 328         pgio->pg_test = NULL;
 329 }
 330
 331 static inline void
 332 pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *ino)
 333 {
 334         pgio->pg_test = NULL;
 335 }
 336
 337 static inline void
 338 pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
 339 {
 340 }
 341
 342 static inline int
 343 pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how)
 344 {
 345         return PNFS_NOT_ATTEMPTED;
 346 }
 347
 348 static inline struct list_head *
 349 pnfs_choose_commit_list(struct nfs_page *req, struct list_head *mds)
 350 {
 351         return mds;
 352 }
 353
 354 static inline void pnfs_clear_request_commit(struct nfs_page *req)
 355 {
 356 }
 357
 358 static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 359 {
 360         return 0;
 361 }
 362
 363 static inline void nfs4_deviceid_purge_client(struct nfs_client *ncl)
 364 {
 365 }
 366 #endif /* CONFIG_NFS_V4_1 */
 367
 368 #endif /* FS_NFS_PNFS_H */