]> git.proxmox.com Git - mirror_ubuntu-focal-kernel.git/blob - include/linux/seq_file.h
procfs: speed up /proc/pid/stat, statm
[mirror_ubuntu-focal-kernel.git] / 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/mutex.h>
7 #include <linux/cpumask.h>
8 #include <linux/nodemask.h>
9
10 struct seq_operations;
11 struct file;
12 struct path;
13 struct inode;
14 struct dentry;
15
16 struct seq_file {
17 char *buf;
18 size_t size;
19 size_t from;
20 size_t count;
21 loff_t index;
22 loff_t read_pos;
23 u64 version;
24 struct mutex lock;
25 const struct seq_operations *op;
26 int poll_event;
27 void *private;
28 };
29
30 struct seq_operations {
31 void * (*start) (struct seq_file *m, loff_t *pos);
32 void (*stop) (struct seq_file *m, void *v);
33 void * (*next) (struct seq_file *m, void *v, loff_t *pos);
34 int (*show) (struct seq_file *m, void *v);
35 };
36
37 #define SEQ_SKIP 1
38
39 /**
40 * seq_get_buf - get buffer to write arbitrary data to
41 * @m: the seq_file handle
42 * @bufp: the beginning of the buffer is stored here
43 *
44 * Return the number of bytes available in the buffer, or zero if
45 * there's no space.
46 */
47 static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
48 {
49 BUG_ON(m->count > m->size);
50 if (m->count < m->size)
51 *bufp = m->buf + m->count;
52 else
53 *bufp = NULL;
54
55 return m->size - m->count;
56 }
57
58 /**
59 * seq_commit - commit data to the buffer
60 * @m: the seq_file handle
61 * @num: the number of bytes to commit
62 *
63 * Commit @num bytes of data written to a buffer previously acquired
64 * by seq_buf_get. To signal an error condition, or that the data
65 * didn't fit in the available space, pass a negative @num value.
66 */
67 static inline void seq_commit(struct seq_file *m, int num)
68 {
69 if (num < 0) {
70 m->count = m->size;
71 } else {
72 BUG_ON(m->count + num > m->size);
73 m->count += num;
74 }
75 }
76
77 char *mangle_path(char *s, const char *p, const char *esc);
78 int seq_open(struct file *, const struct seq_operations *);
79 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
80 loff_t seq_lseek(struct file *, loff_t, int);
81 int seq_release(struct inode *, struct file *);
82 int seq_escape(struct seq_file *, const char *, const char *);
83 int seq_putc(struct seq_file *m, char c);
84 int seq_puts(struct seq_file *m, const char *s);
85 int seq_write(struct seq_file *seq, const void *data, size_t len);
86
87 __printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
88
89 int seq_path(struct seq_file *, const struct path *, const char *);
90 int seq_dentry(struct seq_file *, struct dentry *, const char *);
91 int seq_path_root(struct seq_file *m, const struct path *path,
92 const struct path *root, const char *esc);
93 int seq_bitmap(struct seq_file *m, const unsigned long *bits,
94 unsigned int nr_bits);
95 static inline int seq_cpumask(struct seq_file *m, const struct cpumask *mask)
96 {
97 return seq_bitmap(m, cpumask_bits(mask), nr_cpu_ids);
98 }
99
100 static inline int seq_nodemask(struct seq_file *m, nodemask_t *mask)
101 {
102 return seq_bitmap(m, mask->bits, MAX_NUMNODES);
103 }
104
105 int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,
106 unsigned int nr_bits);
107
108 static inline int seq_cpumask_list(struct seq_file *m,
109 const struct cpumask *mask)
110 {
111 return seq_bitmap_list(m, cpumask_bits(mask), nr_cpu_ids);
112 }
113
114 static inline int seq_nodemask_list(struct seq_file *m, nodemask_t *mask)
115 {
116 return seq_bitmap_list(m, mask->bits, MAX_NUMNODES);
117 }
118
119 int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
120 int single_release(struct inode *, struct file *);
121 void *__seq_open_private(struct file *, const struct seq_operations *, int);
122 int seq_open_private(struct file *, const struct seq_operations *, int);
123 int seq_release_private(struct inode *, struct file *);
124 int seq_put_decimal_ull(struct seq_file *m, char delimiter,
125 unsigned long long num);
126 int seq_put_decimal_ll(struct seq_file *m, char delimiter,
127 long long num);
128
129 #define SEQ_START_TOKEN ((void *)1)
130 /*
131 * Helpers for iteration over list_head-s in seq_files
132 */
133
134 extern struct list_head *seq_list_start(struct list_head *head,
135 loff_t pos);
136 extern struct list_head *seq_list_start_head(struct list_head *head,
137 loff_t pos);
138 extern struct list_head *seq_list_next(void *v, struct list_head *head,
139 loff_t *ppos);
140
141 /*
142 * Helpers for iteration over hlist_head-s in seq_files
143 */
144
145 extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
146 loff_t pos);
147 extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
148 loff_t pos);
149 extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
150 loff_t *ppos);
151
152 extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
153 loff_t pos);
154 extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
155 loff_t pos);
156 extern struct hlist_node *seq_hlist_next_rcu(void *v,
157 struct hlist_head *head,
158 loff_t *ppos);
159 #endif