libcfs/include/libcfs/params_tree.h

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