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