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  * Copyright (c) 2012, Intel Corporation.
  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 #include <libcfs/libcfs.h>
  44
  45 #undef LPROCFS
  46 #if (defined(__KERNEL__) && defined(CONFIG_PROC_FS))
  47 # define LPROCFS
  48 #endif
  49
  50 #ifdef LPROCFS
  51 typedef struct file                             cfs_param_file_t;
  52 typedef struct inode                            cfs_inode_t;
  53 typedef struct proc_inode                       cfs_proc_inode_t;
  54 typedef struct seq_file                         cfs_seq_file_t;
  55 typedef struct seq_operations                   cfs_seq_ops_t;
  56 typedef struct file_operations                  cfs_param_file_ops_t;
  57 typedef cfs_module_t                           *cfs_param_module_t;
  58 typedef struct proc_dir_entry                   cfs_param_dentry_t;
  59 typedef struct poll_table_struct                cfs_poll_table_t;
  60 #define CFS_PARAM_MODULE                        THIS_MODULE
  61 #define CFS_PDE(value)                          PDE(value)
  62 #define cfs_file_private(file)                  (file->private_data)
  63 #define cfs_dentry_data(dentry)                 (dentry->data)
  64 #define cfs_proc_inode_pde(proc_inode)          (proc_inode->pde)
  65 #define cfs_proc_inode(proc_inode)              (proc_inode->vfs_inode)
  66 #define cfs_seq_read_common                     seq_read
  67 #define cfs_seq_lseek_common                    seq_lseek
  68 #define cfs_seq_private(seq)                    (seq->private)
  69 #define cfs_seq_printf(seq, format, ...)        seq_printf(seq, format,  \
  70                                                            ## __VA_ARGS__)
  71 #define cfs_seq_release(inode, file)            seq_release(inode, file)
  72 #define cfs_seq_puts(seq, s)                    seq_puts(seq, s)
  73 #define cfs_seq_putc(seq, s)                    seq_putc(seq, s)
  74 #define cfs_seq_read(file, buf, count, ppos, rc) (rc = seq_read(file, buf, \
  75                                                             count, ppos))
  76 #define cfs_seq_open(file, ops, rc)             (rc = seq_open(file, ops))
  77
  78 /* in lprocfs_stat.c, to protect the private data for proc entries */
  79 extern struct rw_semaphore              _lprocfs_lock;
  80
  81 /* to begin from 2.6.23, Linux defines self file_operations (proc_reg_file_ops)
  82  * in procfs, the proc file_operation defined by Lustre (lprocfs_generic_fops)
  83  * will be wrapped into the new defined proc_reg_file_ops, which instroduces
  84  * user count in proc_dir_entrey(pde_users) to protect the proc entry from
  85  * being deleted. then the protection lock (_lprocfs_lock) defined by Lustre
  86  * isn't necessary anymore for lprocfs_generic_fops(e.g. lprocfs_fops_read).
  87  * see bug19706 for detailed information.
  88  */
  89 #ifndef HAVE_PROCFS_USERS
  90
  91 #define LPROCFS_ENTRY()         \
  92 do {                                    \
  93         down_read(&_lprocfs_lock);      \
  94 } while(0)
  95
  96 #define LPROCFS_EXIT()                  \
  97 do {                                    \
  98         up_read(&_lprocfs_lock);        \
  99 } while(0)
 100
 101 #else
 102 #define LPROCFS_ENTRY() do{ }while(0)
 103 #define LPROCFS_EXIT()  do{ }while(0)
 104 #endif
 105
 106 #ifdef HAVE_PROCFS_DELETED
 107
 108 static inline
 109 int LPROCFS_ENTRY_AND_CHECK(struct proc_dir_entry *dp)
 110 {
 111         LPROCFS_ENTRY();
 112         if ((dp)->deleted) {
 113                 LPROCFS_EXIT();
 114                 return -ENODEV;
 115         }
 116         return 0;
 117 }
 118 #elif defined(HAVE_PROCFS_USERS) /* !HAVE_PROCFS_DELETED*/
 119 static inline
 120 int LPROCFS_ENTRY_AND_CHECK(struct proc_dir_entry *dp)
 121 {
 122         int deleted = 0;
 123
 124         spin_lock(&(dp)->pde_unload_lock);
 125         if (dp->proc_fops == NULL)
 126                 deleted = 1;
 127         spin_unlock(&(dp)->pde_unload_lock);
 128         if (deleted)
 129                 return -ENODEV;
 130         return 0;
 131 }
 132 #else /* !HAVE_PROCFS_DELETED*/
 133 static inline
 134 int LPROCFS_ENTRY_AND_CHECK(struct proc_dir_entry *dp)
 135 {
 136         LPROCFS_ENTRY();
 137         return 0;
 138 }
 139 #endif /* HAVE_PROCFS_DELETED */
 140 #define LPROCFS_SRCH_ENTRY()            \
 141 do {                                    \
 142         down_read(&_lprocfs_lock);      \
 143 } while(0)
 144
 145 #define LPROCFS_SRCH_EXIT()             \
 146 do {                                    \
 147         up_read(&_lprocfs_lock);        \
 148 } while(0)
 149
 150 #define LPROCFS_WRITE_ENTRY()           \
 151 do {                                    \
 152         down_write(&_lprocfs_lock);     \
 153 } while(0)
 154
 155 #define LPROCFS_WRITE_EXIT()            \
 156 do {                                    \
 157         up_write(&_lprocfs_lock);       \
 158 } while(0)
 159 #else /* !LPROCFS */
 160
 161 typedef struct cfs_params_file {
 162         void           *param_private;
 163         loff_t          param_pos;
 164         unsigned int    param_flags;
 165 } cfs_param_file_t;
 166
 167 typedef struct cfs_param_inode {
 168         void    *param_private;
 169 } cfs_inode_t;
 170
 171 typedef struct cfs_param_dentry {
 172         void *param_data;
 173 } cfs_param_dentry_t;
 174
 175 typedef struct cfs_proc_inode {
 176         cfs_param_dentry_t *param_pde;
 177         cfs_inode_t         param_inode;
 178 } cfs_proc_inode_t;
 179
 180 struct cfs_seq_operations;
 181 typedef struct cfs_seq_file {
 182         char                      *buf;
 183         size_t                     size;
 184         size_t                     from;
 185         size_t                     count;
 186         loff_t                     index;
 187         loff_t                     version;
 188         struct mutex                    lock;
 189         struct cfs_seq_operations *op;
 190         void                      *private;
 191 } cfs_seq_file_t;
 192
 193 typedef struct cfs_seq_operations {
 194         void *(*start) (cfs_seq_file_t *m, loff_t *pos);
 195         void  (*stop) (cfs_seq_file_t *m, void *v);
 196         void *(*next) (cfs_seq_file_t *m, void *v, loff_t *pos);
 197         int   (*show) (cfs_seq_file_t *m, void *v);
 198 } cfs_seq_ops_t;
 199
 200 typedef void *cfs_param_module_t;
 201 typedef void *cfs_poll_table_t;
 202
 203 typedef struct cfs_param_file_ops {
 204         cfs_param_module_t owner;
 205         int (*open) (cfs_inode_t *, struct file *);
 206         loff_t (*llseek)(struct file *, loff_t, int);
 207         int (*release) (cfs_inode_t *, cfs_param_file_t *);
 208         unsigned int (*poll) (struct file *, cfs_poll_table_t *);
 209         ssize_t (*write) (struct file *, const char *, size_t, loff_t *);
 210         ssize_t (*read)(struct file *, char *, size_t, loff_t *);
 211 } cfs_param_file_ops_t;
 212 typedef cfs_param_file_ops_t *cfs_lproc_filep_t;
 213
 214 static inline cfs_proc_inode_t *FAKE_PROC_I(const cfs_inode_t *inode)
 215 {
 216         return container_of(inode, cfs_proc_inode_t, param_inode);
 217 }
 218
 219 static inline cfs_param_dentry_t *FAKE_PDE(cfs_inode_t *inode)
 220 {
 221         return FAKE_PROC_I(inode)->param_pde;
 222 }
 223
 224 #define CFS_PARAM_MODULE                        NULL
 225 #define CFS_PDE(value)                          FAKE_PDE(value)
 226 #define cfs_file_private(file)                  (file->param_private)
 227 #define cfs_dentry_data(dentry)                 (dentry->param_data)
 228 #define cfs_proc_inode(proc_inode)              (proc_inode->param_inode)
 229 #define cfs_proc_inode_pde(proc_inode)          (proc_inode->param_pde)
 230 #define cfs_seq_read_common                     NULL
 231 #define cfs_seq_lseek_common                    NULL
 232 #define cfs_seq_private(seq)                    (seq->private)
 233 #define cfs_seq_read(file, buf, count, ppos, rc) do {} while(0)
 234 #define cfs_seq_open(file, ops, rc)                     \
 235 do {                                                    \
 236          cfs_seq_file_t *p = cfs_file_private(file);    \
 237          if (!p) {                                      \
 238                 LIBCFS_ALLOC(p, sizeof(*p));            \
 239                 if (!p) {                               \
 240                         rc = -ENOMEM;                   \
 241                         break;                          \
 242                 }                                       \
 243                 cfs_file_private(file) = p;             \
 244         }                                               \
 245         memset(p, 0, sizeof(*p));                       \
 246         p->op = ops;                                    \
 247         rc = 0;                                         \
 248 } while(0)
 249
 250 #define LPROCFS_ENTRY()             do {} while(0)
 251 #define LPROCFS_EXIT()              do {} while(0)
 252 static inline
 253 int LPROCFS_ENTRY_AND_CHECK(cfs_param_dentry_t *dp)
 254 {
 255         LPROCFS_ENTRY();
 256         return 0;
 257 }
 258 #define LPROCFS_WRITE_ENTRY()       do {} while(0)
 259 #define LPROCFS_WRITE_EXIT()        do {} while(0)
 260
 261 #endif /* LPROCFS */
 262
 263 /* XXX: params_tree APIs */
 264
 265 #endif  /* __PARAMS_TREE_H__ */