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