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/** 152 * seq_show_options - display mount options with appropriate escapes. 153 * @m: the seq_file handle 154 * @name: the mount option name 155 * @value: the mount option name's value, can be NULL 156 */ 157static inline void seq_show_option(struct seq_file *m, const char *name, 158 const char *value) 159{ 160 seq_putc(m, ','); 161 seq_escape(m, name, ",= \t\n\\"); 162 if (value) { 163 seq_putc(m, '='); 164 seq_escape(m, value, ", \t\n\\"); 165 } 166} 167 168/** 169 * seq_show_option_n - display mount options with appropriate escapes 170 * where @value must be a specific length. 171 * @m: the seq_file handle 172 * @name: the mount option name 173 * @value: the mount option name's value, cannot be NULL 174 * @length: the length of @value to display 175 * 176 * This is a macro since this uses "length" to define the size of the 177 * stack buffer. 178 */ 179#define seq_show_option_n(m, name, value, length) { \ 180 char val_buf[length + 1]; \ 181 strncpy(val_buf, value, length); \ 182 val_buf[length] = '\0'; \ 183 seq_show_option(m, name, val_buf); \ 184} 185 186#define SEQ_START_TOKEN ((void *)1) 187/* 188 * Helpers for iteration over list_head-s in seq_files 189 */ 190 191extern struct list_head *seq_list_start(struct list_head *head, 192 loff_t pos); 193extern struct list_head *seq_list_start_head(struct list_head *head, 194 loff_t pos); 195extern struct list_head *seq_list_next(void *v, struct list_head *head, 196 loff_t *ppos); 197 198/* 199 * Helpers for iteration over hlist_head-s in seq_files 200 */ 201 202extern struct hlist_node *seq_hlist_start(struct hlist_head *head, 203 loff_t pos); 204extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head, 205 loff_t pos); 206extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, 207 loff_t *ppos); 208 209extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, 210 loff_t pos); 211extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, 212 loff_t pos); 213extern struct hlist_node *seq_hlist_next_rcu(void *v, 214 struct hlist_head *head, 215 loff_t *ppos); 216 217/* Helpers for iterating over per-cpu hlist_head-s in seq_files */ 218extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos); 219 220extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos); 221 222#endif 223