include/linux/seq_file.h

   1 #ifndef _LINUX_SEQ_FILE_H
   2 #define _LINUX_SEQ_FILE_H
   3
   4 #include <linux/types.h>
   5 #include <linux/string.h>
   6 #include <linux/bug.h>
   7 #include <linux/mutex.h>
   8 #include <linux/cpumask.h>
   9 #include <linux/nodemask.h>
  10
  11 struct seq_operations;
  12 struct file;
  13 struct path;
  14 struct inode;
  15 struct dentry;
  16 struct user_namespace;
  17
  18 struct seq_file {
  19         char *buf;
  20         size_t size;
  21         size_t from;
  22         size_t count;
  23         size_t pad_until;
  24         loff_t index;
  25         loff_t read_pos;
  26         u64 version;
  27         struct mutex lock;
  28         const struct seq_operations *op;
  29         int poll_event;
  30 #ifdef CONFIG_USER_NS
  31         struct user_namespace *user_ns;
  32 #endif
  33         void *private;
  34 };
  35
  36 struct seq_operations {
  37         void * (*start) (struct seq_file *m, loff_t *pos);
  38         void (*stop) (struct seq_file *m, void *v);
  39         void * (*next) (struct seq_file *m, void *v, loff_t *pos);
  40         int (*show) (struct seq_file *m, void *v);
  41 };
  42
  43 #define SEQ_SKIP 1
  44
  45 /**
  46  * seq_get_buf - get buffer to write arbitrary data to
  47  * @m: the seq_file handle
  48  * @bufp: the beginning of the buffer is stored here
  49  *
  50  * Return the number of bytes available in the buffer, or zero if
  51  * there's no space.
  52  */
  53 static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
  54 {
  55         BUG_ON(m->count > m->size);
  56         if (m->count < m->size)
  57                 *bufp = m->buf + m->count;
  58         else
  59                 *bufp = NULL;
  60
  61         return m->size - m->count;
  62 }
  63
  64 /**
  65  * seq_commit - commit data to the buffer
  66  * @m: the seq_file handle
  67  * @num: the number of bytes to commit
  68  *
  69  * Commit @num bytes of data written to a buffer previously acquired
  70  * by seq_buf_get.  To signal an error condition, or that the data
  71  * didn't fit in the available space, pass a negative @num value.
  72  */
  73 static inline void seq_commit(struct seq_file *m, int num)
  74 {
  75         if (num < 0) {
  76                 m->count = m->size;
  77         } else {
  78                 BUG_ON(m->count + num > m->size);
  79                 m->count += num;
  80         }
  81 }
  82
  83 /**
  84  * seq_setwidth - set padding width
  85  * @m: the seq_file handle
  86  * @size: the max number of bytes to pad.
  87  *
  88  * Call seq_setwidth() for setting max width, then call seq_printf() etc. and
  89  * finally call seq_pad() to pad the remaining bytes.
  90  */
  91 static inline void seq_setwidth(struct seq_file *m, size_t size)
  92 {
  93         m->pad_until = m->count + size;
  94 }
  95 void seq_pad(struct seq_file *m, char c);
  96
  97 char *mangle_path(char *s, const char *p, const char *esc);
  98 int seq_open(struct file *, const struct seq_operations *);
  99 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
 100 loff_t seq_lseek(struct file *, loff_t, int);
 101 int seq_release(struct inode *, struct file *);
 102 int seq_escape(struct seq_file *, const char *, const char *);
 103 int seq_putc(struct seq_file *m, char c);
 104 int seq_puts(struct seq_file *m, const char *s);
 105 int seq_write(struct seq_file *seq, const void *data, size_t len);
 106
 107 __printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
 108 __printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args);
 109
 110 int seq_path(struct seq_file *, const struct path *, const char *);
 111 int seq_dentry(struct seq_file *, struct dentry *, const char *);
 112 int seq_path_root(struct seq_file *m, const struct path *path,
 113                   const struct path *root, const char *esc);
 114 int seq_bitmap(struct seq_file *m, const unsigned long *bits,
 115                                    unsigned int nr_bits);
 116 static inline int seq_cpumask(struct seq_file *m, const struct cpumask *mask)
 117 {
 118         return seq_bitmap(m, cpumask_bits(mask), nr_cpu_ids);
 119 }
 120
 121 static inline int seq_nodemask(struct seq_file *m, nodemask_t *mask)
 122 {
 123         return seq_bitmap(m, mask->bits, MAX_NUMNODES);
 124 }
 125
 126 int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,
 127                 unsigned int nr_bits);
 128
 129 static inline int seq_cpumask_list(struct seq_file *m,
 130                                    const struct cpumask *mask)
 131 {
 132         return seq_bitmap_list(m, cpumask_bits(mask), nr_cpu_ids);
 133 }
 134
 135 static inline int seq_nodemask_list(struct seq_file *m, nodemask_t *mask)
 136 {
 137         return seq_bitmap_list(m, mask->bits, MAX_NUMNODES);
 138 }
 139
 140 int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
 141 int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
 142 int single_release(struct inode *, struct file *);
 143 void *__seq_open_private(struct file *, const struct seq_operations *, int);
 144 int seq_open_private(struct file *, const struct seq_operations *, int);
 145 int seq_release_private(struct inode *, struct file *);
 146 int seq_put_decimal_ull(struct seq_file *m, char delimiter,
 147                         unsigned long long num);
 148 int seq_put_decimal_ll(struct seq_file *m, char delimiter,
 149                         long long num);
 150
 151 static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
 152 {
 153 #ifdef CONFIG_USER_NS
 154         return seq->user_ns;
 155 #else
 156         extern struct user_namespace init_user_ns;
 157         return &init_user_ns;
 158 #endif
 159 }
 160
 161 #define SEQ_START_TOKEN ((void *)1)
 162 /*
 163  * Helpers for iteration over list_head-s in seq_files
 164  */
 165
 166 extern struct list_head *seq_list_start(struct list_head *head,
 167                 loff_t pos);
 168 extern struct list_head *seq_list_start_head(struct list_head *head,
 169                 loff_t pos);
 170 extern struct list_head *seq_list_next(void *v, struct list_head *head,
 171                 loff_t *ppos);
 172
 173 /*
 174  * Helpers for iteration over hlist_head-s in seq_files
 175  */
 176
 177 extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
 178                                           loff_t pos);
 179 extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
 180                                                loff_t pos);
 181 extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
 182                                          loff_t *ppos);
 183
 184 extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
 185                                               loff_t pos);
 186 extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
 187                                                    loff_t pos);
 188 extern struct hlist_node *seq_hlist_next_rcu(void *v,
 189                                                    struct hlist_head *head,
 190                                                    loff_t *ppos);
 191
 192 /* Helpers for iterating over per-cpu hlist_head-s in seq_files */
 193 extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);
 194
 195 extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
 196
 197 #endif