linux_dsm_epyc7002/include/linux/seq_file.h
Al Viro 2043f495c7 new helper: single_open_size()
Same as single_open(), but preallocates the buffer of given size.
Doesn't make any sense for sizes up to PAGE_SIZE and doesn't make
sense if output of show() exceeds PAGE_SIZE only rarely - seq_read()
will take care of growing the buffer and redoing show().  If you
_know_ that it will be large, it might make more sense to look into
saner iterator, rather than go with single-shot one.  If that's
impossible, single_open_size() might be for you.

Again, don't use that without a good reason; occasionally that's really
the best way to go, but very often there are better solutions.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:13:29 -04:00

177 lines
5.1 KiB
C

#ifndef _LINUX_SEQ_FILE_H
#define _LINUX_SEQ_FILE_H
#include <linux/types.h>
#include <linux/string.h>
#include <linux/bug.h>
#include <linux/mutex.h>
#include <linux/cpumask.h>
#include <linux/nodemask.h>
struct seq_operations;
struct file;
struct path;
struct inode;
struct dentry;
struct user_namespace;
struct seq_file {
char *buf;
size_t size;
size_t from;
size_t count;
loff_t index;
loff_t read_pos;
u64 version;
struct mutex lock;
const struct seq_operations *op;
int poll_event;
#ifdef CONFIG_USER_NS
struct user_namespace *user_ns;
#endif
void *private;
};
struct seq_operations {
void * (*start) (struct seq_file *m, loff_t *pos);
void (*stop) (struct seq_file *m, void *v);
void * (*next) (struct seq_file *m, void *v, loff_t *pos);
int (*show) (struct seq_file *m, void *v);
};
#define SEQ_SKIP 1
/**
* seq_get_buf - get buffer to write arbitrary data to
* @m: the seq_file handle
* @bufp: the beginning of the buffer is stored here
*
* Return the number of bytes available in the buffer, or zero if
* there's no space.
*/
static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
{
BUG_ON(m->count > m->size);
if (m->count < m->size)
*bufp = m->buf + m->count;
else
*bufp = NULL;
return m->size - m->count;
}
/**
* seq_commit - commit data to the buffer
* @m: the seq_file handle
* @num: the number of bytes to commit
*
* Commit @num bytes of data written to a buffer previously acquired
* by seq_buf_get. To signal an error condition, or that the data
* didn't fit in the available space, pass a negative @num value.
*/
static inline void seq_commit(struct seq_file *m, int num)
{
if (num < 0) {
m->count = m->size;
} else {
BUG_ON(m->count + num > m->size);
m->count += num;
}
}
char *mangle_path(char *s, const char *p, const char *esc);
int seq_open(struct file *, const struct seq_operations *);
ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
loff_t seq_lseek(struct file *, loff_t, int);
int seq_release(struct inode *, struct file *);
int seq_escape(struct seq_file *, const char *, const char *);
int seq_putc(struct seq_file *m, char c);
int seq_puts(struct seq_file *m, const char *s);
int seq_write(struct seq_file *seq, const void *data, size_t len);
__printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
__printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args);
int seq_path(struct seq_file *, const struct path *, const char *);
int seq_dentry(struct seq_file *, struct dentry *, const char *);
int seq_path_root(struct seq_file *m, const struct path *path,
const struct path *root, const char *esc);
int seq_bitmap(struct seq_file *m, const unsigned long *bits,
unsigned int nr_bits);
static inline int seq_cpumask(struct seq_file *m, const struct cpumask *mask)
{
return seq_bitmap(m, cpumask_bits(mask), nr_cpu_ids);
}
static inline int seq_nodemask(struct seq_file *m, nodemask_t *mask)
{
return seq_bitmap(m, mask->bits, MAX_NUMNODES);
}
int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,
unsigned int nr_bits);
static inline int seq_cpumask_list(struct seq_file *m,
const struct cpumask *mask)
{
return seq_bitmap_list(m, cpumask_bits(mask), nr_cpu_ids);
}
static inline int seq_nodemask_list(struct seq_file *m, nodemask_t *mask)
{
return seq_bitmap_list(m, mask->bits, MAX_NUMNODES);
}
int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
int single_release(struct inode *, struct file *);
void *__seq_open_private(struct file *, const struct seq_operations *, int);
int seq_open_private(struct file *, const struct seq_operations *, int);
int seq_release_private(struct inode *, struct file *);
int seq_put_decimal_ull(struct seq_file *m, char delimiter,
unsigned long long num);
int seq_put_decimal_ll(struct seq_file *m, char delimiter,
long long num);
static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
{
#ifdef CONFIG_USER_NS
return seq->user_ns;
#else
extern struct user_namespace init_user_ns;
return &init_user_ns;
#endif
}
#define SEQ_START_TOKEN ((void *)1)
/*
* Helpers for iteration over list_head-s in seq_files
*/
extern struct list_head *seq_list_start(struct list_head *head,
loff_t pos);
extern struct list_head *seq_list_start_head(struct list_head *head,
loff_t pos);
extern struct list_head *seq_list_next(void *v, struct list_head *head,
loff_t *ppos);
/*
* Helpers for iteration over hlist_head-s in seq_files
*/
extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
loff_t pos);
extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
loff_t pos);
extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
loff_t *ppos);
extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
loff_t pos);
extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
loff_t pos);
extern struct hlist_node *seq_hlist_next_rcu(void *v,
struct hlist_head *head,
loff_t *ppos);
#endif