libcfs/include/libcfs/params_tree.h

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * API and structure definitions for params_tree.
  37  *
  38  * Author: LiuYing <emoly.liu@oracle.com>
  39  */
  40 #ifndef __PARAMS_TREE_H__
  41 #define __PARAMS_TREE_H__
  42
  43 #ifndef EXPORT_SYMTAB
  44 # define EXPORT_SYMTAB
  45 #endif
  46
  47 #include <libcfs/libcfs.h>
  48
  49 #undef LPROCFS
  50 #if (defined(__KERNEL__) && defined(CONFIG_PROC_FS))
  51 # define LPROCFS
  52 #endif
  53
  54 #ifdef LPROCFS
  55 typedef struct file                             cfs_param_file_t;
  56 typedef struct inode                            cfs_inode_t;
  57 typedef struct proc_inode                       cfs_proc_inode_t;
  58 typedef struct seq_file                         cfs_seq_file_t;
  59 typedef struct seq_operations                   cfs_seq_ops_t;
  60 typedef struct file_operations                  cfs_param_file_ops_t;
  61 typedef cfs_module_t                           *cfs_param_module_t;
  62 typedef struct proc_dir_entry                   cfs_param_dentry_t;
  63 typedef struct poll_table_struct                cfs_poll_table_t;
  64 #define CFS_PARAM_MODULE                        THIS_MODULE
  65 #define CFS_PDE(value)                          PDE(value)
  66 #define cfs_file_private(file)                  (file->private_data)
  67 #define cfs_dentry_data(dentry)                 (dentry->data)
  68 #define cfs_proc_inode_pde(proc_inode)          (proc_inode->pde)
  69 #define cfs_proc_inode(proc_inode)              (proc_inode->vfs_inode)
  70 #define cfs_seq_read_common                     seq_read
  71 #define cfs_seq_lseek_common                    seq_lseek
  72 #define cfs_seq_private(seq)                    (seq->private)
  73 #define cfs_seq_printf(seq, format, ...)        seq_printf(seq, format,  \
  74                                                            ## __VA_ARGS__)
  75 #define cfs_seq_release(inode, file)            seq_release(inode, file)
  76 #define cfs_seq_puts(seq, s)                    seq_puts(seq, s)
  77 #define cfs_seq_putc(seq, s)                    seq_putc(seq, s)
  78 #define cfs_seq_read(file, buf, count, ppos, rc) (rc = seq_read(file, buf, \
  79                                                             count, ppos))
  80 #define cfs_seq_open(file, ops, rc)             (rc = seq_open(file, ops))
  81
  82 /* in lprocfs_stat.c, to protect the private data for proc entries */
  83 extern cfs_rw_semaphore_t       _lprocfs_lock;
  84
  85 /* to begin from 2.6.23, Linux defines self file_operations (proc_reg_file_ops)
  86  * in procfs, the proc file_operation defined by Lustre (lprocfs_generic_fops)
  87  * will be wrapped into the new defined proc_reg_file_ops, which instroduces
  88  * user count in proc_dir_entrey(pde_users) to protect the proc entry from
  89  * being deleted. then the protection lock (_lprocfs_lock) defined by Lustre
  90  * isn't necessary anymore for lprocfs_generic_fops(e.g. lprocfs_fops_read).
  91  * see bug19706 for detailed information.
  92  */
  93 #ifndef HAVE_PROCFS_USERS
  94
  95 #define LPROCFS_ENTRY()                 \
  96 do {                                    \
  97         cfs_down_read(&_lprocfs_lock);  \
  98 } while(0)
  99
 100 #define LPROCFS_EXIT()                  \
 101 do {                                    \
 102         cfs_up_read(&_lprocfs_lock);    \
 103 } while(0)
 104
 105 #else
 106 #define LPROCFS_ENTRY() do{ }while(0)
 107 #define LPROCFS_EXIT()  do{ }while(0)
 108 #endif
 109
 110 #ifdef HAVE_PROCFS_DELETED
 111
 112 #ifdef HAVE_PROCFS_USERS
 113 #error proc_dir_entry->deleted is conflicted with proc_dir_entry->pde_users
 114 #endif
 115
 116 static inline
 117 int LPROCFS_ENTRY_AND_CHECK(struct proc_dir_entry *dp)
 118 {
 119         LPROCFS_ENTRY();
 120         if ((dp)->deleted) {
 121                 LPROCFS_EXIT();
 122                 return -ENODEV;
 123         }
 124         return 0;
 125 }
 126 #elif defined(HAVE_PROCFS_USERS) /* !HAVE_PROCFS_DELETED*/
 127 static inline
 128 int LPROCFS_ENTRY_AND_CHECK(struct proc_dir_entry *dp)
 129 {
 130         int deleted = 0;
 131         spin_lock(&(dp)->pde_unload_lock);
 132         if (dp->proc_fops == NULL)
 133                 deleted = 1;
 134         spin_unlock(&(dp)->pde_unload_lock);
 135         if (deleted)
 136                 return -ENODEV;
 137         return 0;
 138 }
 139 #else /* !HAVE_PROCFS_DELETED*/
 140 static inline
 141 int LPROCFS_ENTRY_AND_CHECK(struct proc_dir_entry *dp)
 142 {
 143         LPROCFS_ENTRY();
 144         return 0;
 145 }
 146 #endif /* HAVE_PROCFS_DELETED */
 147 #define LPROCFS_SRCH_ENTRY()            \
 148 do {                                    \
 149         down_read(&_lprocfs_lock);      \
 150 } while(0)
 151
 152 #define LPROCFS_SRCH_EXIT()             \
 153 do {                                    \
 154         up_read(&_lprocfs_lock);        \
 155 } while(0)
 156
 157 #define LPROCFS_WRITE_ENTRY()           \
 158 do {                                    \
 159         cfs_down_write(&_lprocfs_lock); \
 160 } while(0)
 161
 162 #define LPROCFS_WRITE_EXIT()            \
 163 do {                                    \
 164         cfs_up_write(&_lprocfs_lock);   \
 165 } while(0)
 166 #else /* !LPROCFS */
 167
 168 typedef struct cfs_params_file {
 169         void           *param_private;
 170         loff_t          param_pos;
 171         unsigned int    param_flags;
 172 } cfs_param_file_t;
 173
 174 typedef struct cfs_param_inode {
 175         void    *param_private;
 176 } cfs_inode_t;
 177
 178 typedef struct cfs_param_dentry {
 179         void *param_data;
 180 } cfs_param_dentry_t;
 181
 182 typedef struct cfs_proc_inode {
 183         cfs_param_dentry_t *param_pde;
 184         cfs_inode_t         param_inode;
 185 } cfs_proc_inode_t;
 186
 187 struct cfs_seq_operations;
 188 typedef struct cfs_seq_file {
 189         char                      *buf;
 190         size_t                     size;
 191         size_t                     from;
 192         size_t                     count;
 193         loff_t                     index;
 194         loff_t                     version;
 195         cfs_mutex_t                lock;
 196         struct cfs_seq_operations *op;
 197         void                      *private;
 198 } cfs_seq_file_t;
 199
 200 typedef struct cfs_seq_operations {
 201         void *(*start) (cfs_seq_file_t *m, loff_t *pos);
 202         void  (*stop) (cfs_seq_file_t *m, void *v);
 203         void *(*next) (cfs_seq_file_t *m, void *v, loff_t *pos);
 204         int   (*show) (cfs_seq_file_t *m, void *v);
 205 } cfs_seq_ops_t;
 206
 207 typedef void *cfs_param_module_t;
 208 typedef void *cfs_poll_table_t;
 209
 210 typedef struct cfs_param_file_ops {
 211         cfs_param_module_t owner;
 212         int (*open) (cfs_inode_t *, cfs_file_t *);
 213         loff_t (*llseek)(cfs_file_t *, loff_t, int);
 214         int (*release) (cfs_inode_t *, cfs_param_file_t *);
 215         unsigned int (*poll) (cfs_file_t *, cfs_poll_table_t *);
 216         ssize_t (*write) (cfs_file_t *, const char *, size_t, loff_t *);
 217         ssize_t (*read)(cfs_file_t *, char *, size_t, loff_t *);
 218 } cfs_param_file_ops_t;
 219 typedef cfs_param_file_ops_t *cfs_lproc_filep_t;
 220
 221 static inline cfs_proc_inode_t *FAKE_PROC_I(const cfs_inode_t *inode)
 222 {
 223         return container_of(inode, cfs_proc_inode_t, param_inode);
 224 }
 225
 226 static inline cfs_param_dentry_t *FAKE_PDE(cfs_inode_t *inode)
 227 {
 228         return FAKE_PROC_I(inode)->param_pde;
 229 }
 230
 231 #define CFS_PARAM_MODULE                        NULL
 232 #define CFS_PDE(value)                          FAKE_PDE(value)
 233 #define cfs_file_private(file)                  (file->param_private)
 234 #define cfs_dentry_data(dentry)                 (dentry->param_data)
 235 #define cfs_proc_inode(proc_inode)              (proc_inode->param_inode)
 236 #define cfs_proc_inode_pde(proc_inode)          (proc_inode->param_pde)
 237 #define cfs_seq_read_common                     NULL
 238 #define cfs_seq_lseek_common                    NULL
 239 #define cfs_seq_private(seq)                    (seq->private)
 240 #define cfs_seq_read(file, buf, count, ppos, rc) do {} while(0)
 241 #define cfs_seq_open(file, ops, rc)                     \
 242 do {                                                    \
 243          cfs_seq_file_t *p = cfs_file_private(file);    \
 244          if (!p) {                                      \
 245                 LIBCFS_ALLOC(p, sizeof(*p));            \
 246                 if (!p) {                               \
 247                         rc = -ENOMEM;                   \
 248                         break;                          \
 249                 }                                       \
 250                 cfs_file_private(file) = p;             \
 251         }                                               \
 252         memset(p, 0, sizeof(*p));                       \
 253         p->op = ops;                                    \
 254         rc = 0;                                         \
 255 } while(0)
 256
 257 #define LPROCFS_ENTRY()             do {} while(0)
 258 #define LPROCFS_EXIT()              do {} while(0)
 259 static inline
 260 int LPROCFS_ENTRY_AND_CHECK(cfs_param_dentry_t *dp)
 261 {
 262         LPROCFS_ENTRY();
 263         return 0;
 264 }
 265 #define LPROCFS_WRITE_ENTRY()       do {} while(0)
 266 #define LPROCFS_WRITE_EXIT()        do {} while(0)
 267
 268 #endif /* LPROCFS */
 269
 270 /* XXX: params_tree APIs */
 271
 272 #endif  /* __PARAMS_TREE_H__ */