LXR linux/include/linux/seq

   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
  11struct seq_operations;
  12struct file;
  13struct path;
  14struct inode;
  15struct dentry;
  16struct user_namespace;
  17
  18struct 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
  36struct 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_has_overflowed - check if the buffer has overflowed
  47 * @m: the seq_file handle
  48 *
  49 * seq_files have a buffer which may overflow. When this happens a larger
  50 * buffer is reallocated and all the data will be printed again.
  51 * The overflow state is true when m->count == m->size.
  52 *
  53 * Returns true if the buffer received more than it can hold.
  54 */
  55static inline bool seq_has_overflowed(struct seq_file *m)
  56{
  57        return m->count == m->size;
  58}
  59
  60/**
  61 * seq_get_buf - get buffer to write arbitrary data to
  62 * @m: the seq_file handle
  63 * @bufp: the beginning of the buffer is stored here
  64 *
  65 * Return the number of bytes available in the buffer, or zero if
  66 * there's no space.
  67 */
  68static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
  69{
  70        BUG_ON(m->count > m->size);
  71        if (m->count < m->size)
  72                *bufp = m->buf + m->count;
  73        else
  74                *bufp = NULL;
  75
  76        return m->size - m->count;
  77}
  78
  79/**
  80 * seq_commit - commit data to the buffer
  81 * @m: the seq_file handle
  82 * @num: the number of bytes to commit
  83 *
  84 * Commit @num bytes of data written to a buffer previously acquired
  85 * by seq_buf_get.  To signal an error condition, or that the data
  86 * didn't fit in the available space, pass a negative @num value.
  87 */
  88static inline void seq_commit(struct seq_file *m, int num)
  89{
  90        if (num < 0) {
  91                m->count = m->size;
  92        } else {
  93                BUG_ON(m->count + num > m->size);
  94                m->count += num;
  95        }
  96}
  97
  98/**
  99 * seq_setwidth - set padding width
 100 * @m: the seq_file handle
 101 * @size: the max number of bytes to pad.
 102 *
 103 * Call seq_setwidth() for setting max width, then call seq_printf() etc. and
 104 * finally call seq_pad() to pad the remaining bytes.
 105 */
 106static inline void seq_setwidth(struct seq_file *m, size_t size)
 107{
 108        m->pad_until = m->count + size;
 109}
 110void seq_pad(struct seq_file *m, char c);
 111
 112char *mangle_path(char *s, const char *p, const char *esc);
 113int seq_open(struct file *, const struct seq_operations *);
 114ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
 115loff_t seq_lseek(struct file *, loff_t, int);
 116int seq_release(struct inode *, struct file *);
 117int seq_escape(struct seq_file *, const char *, const char *);
 118int seq_putc(struct seq_file *m, char c);
 119int seq_puts(struct seq_file *m, const char *s);
 120int seq_write(struct seq_file *seq, const void *data, size_t len);
 121
 122__printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
 123__printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args);
 124
 125int seq_path(struct seq_file *, const struct path *, const char *);
 126int seq_dentry(struct seq_file *, struct dentry *, const char *);
 127int seq_path_root(struct seq_file *m, const struct path *path,
 128                  const struct path *root, const char *esc);
 129
 130int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
 131int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
 132int single_release(struct inode *, struct file *);
 133void *__seq_open_private(struct file *, const struct seq_operations *, int);
 134int seq_open_private(struct file *, const struct seq_operations *, int);
 135int seq_release_private(struct inode *, struct file *);
 136int seq_put_decimal_ull(struct seq_file *m, char delimiter,
 137                        unsigned long long num);
 138int seq_put_decimal_ll(struct seq_file *m, char delimiter,
 139                        long long num);
 140
 141static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
 142{
 143#ifdef CONFIG_USER_NS
 144        return seq->user_ns;
 145#else
 146        extern struct user_namespace init_user_ns;
 147        return &init_user_ns;
 148#endif
 149}
 150
 151#define SEQ_START_TOKEN ((void *)1)
 152/*
 153 * Helpers for iteration over list_head-s in seq_files
 154 */
 155
 156extern struct list_head *seq_list_start(struct list_head *head,
 157                loff_t pos);
 158extern struct list_head *seq_list_start_head(struct list_head *head,
 159                loff_t pos);
 160extern struct list_head *seq_list_next(void *v, struct list_head *head,
 161                loff_t *ppos);
 162
 163/*
 164 * Helpers for iteration over hlist_head-s in seq_files
 165 */
 166
 167extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
 168                                          loff_t pos);
 169extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
 170                                               loff_t pos);
 171extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
 172                                         loff_t *ppos);
 173
 174extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
 175                                              loff_t pos);
 176extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
 177                                                   loff_t pos);
 178extern struct hlist_node *seq_hlist_next_rcu(void *v,
 179                                                   struct hlist_head *head,
 180                                                   loff_t *ppos);
 181
 182/* Helpers for iterating over per-cpu hlist_head-s in seq_files */
 183extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);
 184
 185extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
 186
 187#endif
 188