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 static inline
  82 int LPROCFS_ENTRY_CHECK(struct proc_dir_entry *dp)
  83 {
  84         int deleted = 0;
  85
  86         spin_lock(&(dp)->pde_unload_lock);
  87         if (dp->proc_fops == NULL)
  88                 deleted = 1;
  89         spin_unlock(&(dp)->pde_unload_lock);
  90         if (deleted)
  91                 return -ENODEV;
  92         return 0;
  93 }
  94 #define LPROCFS_SRCH_ENTRY()            \
  95 do {                                    \
  96         down_read(&_lprocfs_lock);      \
  97 } while(0)
  98
  99 #define LPROCFS_SRCH_EXIT()             \
 100 do {                                    \
 101         up_read(&_lprocfs_lock);        \
 102 } while(0)
 103
 104 #define LPROCFS_WRITE_ENTRY()           \
 105 do {                                    \
 106         down_write(&_lprocfs_lock);     \
 107 } while(0)
 108
 109 #define LPROCFS_WRITE_EXIT()            \
 110 do {                                    \
 111         up_write(&_lprocfs_lock);       \
 112 } while(0)
 113 #else /* !LPROCFS */
 114
 115 typedef struct cfs_params_file {
 116         void           *param_private;
 117         loff_t          param_pos;
 118         unsigned int    param_flags;
 119 } cfs_param_file_t;
 120
 121 typedef struct cfs_param_inode {
 122         void    *param_private;
 123 } cfs_inode_t;
 124
 125 typedef struct cfs_param_dentry {
 126         void *param_data;
 127 } cfs_param_dentry_t;
 128
 129 typedef struct cfs_proc_inode {
 130         cfs_param_dentry_t *param_pde;
 131         cfs_inode_t         param_inode;
 132 } cfs_proc_inode_t;
 133
 134 struct cfs_seq_operations;
 135 typedef struct cfs_seq_file {
 136         char                      *buf;
 137         size_t                     size;
 138         size_t                     from;
 139         size_t                     count;
 140         loff_t                     index;
 141         loff_t                     version;
 142         struct mutex                    lock;
 143         struct cfs_seq_operations *op;
 144         void                      *private;
 145 } cfs_seq_file_t;
 146
 147 typedef struct cfs_seq_operations {
 148         void *(*start) (cfs_seq_file_t *m, loff_t *pos);
 149         void  (*stop) (cfs_seq_file_t *m, void *v);
 150         void *(*next) (cfs_seq_file_t *m, void *v, loff_t *pos);
 151         int   (*show) (cfs_seq_file_t *m, void *v);
 152 } cfs_seq_ops_t;
 153
 154 typedef void *cfs_param_module_t;
 155 typedef void *cfs_poll_table_t;
 156
 157 typedef struct cfs_param_file_ops {
 158         cfs_param_module_t owner;
 159         int (*open) (cfs_inode_t *, struct file *);
 160         loff_t (*llseek)(struct file *, loff_t, int);
 161         int (*release) (cfs_inode_t *, cfs_param_file_t *);
 162         unsigned int (*poll) (struct file *, cfs_poll_table_t *);
 163         ssize_t (*write) (struct file *, const char *, size_t, loff_t *);
 164         ssize_t (*read)(struct file *, char *, size_t, loff_t *);
 165 } cfs_param_file_ops_t;
 166 typedef cfs_param_file_ops_t *cfs_lproc_filep_t;
 167
 168 static inline cfs_proc_inode_t *FAKE_PROC_I(const cfs_inode_t *inode)
 169 {
 170         return container_of(inode, cfs_proc_inode_t, param_inode);
 171 }
 172
 173 static inline cfs_param_dentry_t *FAKE_PDE(cfs_inode_t *inode)
 174 {
 175         return FAKE_PROC_I(inode)->param_pde;
 176 }
 177
 178 #define CFS_PARAM_MODULE                        NULL
 179 #define CFS_PDE(value)                          FAKE_PDE(value)
 180 #define cfs_file_private(file)                  (file->param_private)
 181 #define cfs_dentry_data(dentry)                 (dentry->param_data)
 182 #define cfs_proc_inode(proc_inode)              (proc_inode->param_inode)
 183 #define cfs_proc_inode_pde(proc_inode)          (proc_inode->param_pde)
 184 #define cfs_seq_read_common                     NULL
 185 #define cfs_seq_lseek_common                    NULL
 186 #define cfs_seq_private(seq)                    (seq->private)
 187 #define cfs_seq_read(file, buf, count, ppos, rc) do {} while(0)
 188 #define cfs_seq_open(file, ops, rc)                     \
 189 do {                                                    \
 190          cfs_seq_file_t *p = cfs_file_private(file);    \
 191          if (!p) {                                      \
 192                 LIBCFS_ALLOC(p, sizeof(*p));            \
 193                 if (!p) {                               \
 194                         rc = -ENOMEM;                   \
 195                         break;                          \
 196                 }                                       \
 197                 cfs_file_private(file) = p;             \
 198         }                                               \
 199         memset(p, 0, sizeof(*p));                       \
 200         p->op = ops;                                    \
 201         rc = 0;                                         \
 202 } while(0)
 203
 204 static inline
 205 int LPROCFS_ENTRY_CHECK(cfs_param_dentry_t *dp)
 206 {
 207         return 0;
 208 }
 209 #define LPROCFS_WRITE_ENTRY()       do {} while(0)
 210 #define LPROCFS_WRITE_EXIT()        do {} while(0)
 211
 212 #endif /* LPROCFS */
 213
 214 /* XXX: params_tree APIs */
 215
 216 #endif  /* __PARAMS_TREE_H__ */