diff options
author | Miklos Szeredi <mszeredi@suse.cz> | 2009-09-21 16:48:36 +0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2009-09-24 15:47:35 +0400 |
commit | f84398068d9c2babe41500504ef247ae07081857 (patch) | |
tree | 7306df97a7ee62f314f4db152fb2afceff156988 /include/linux/seq_file.h | |
parent | f9098980ffea9c749622ff8ddf3b6d5831902a46 (diff) | |
download | linux-f84398068d9c2babe41500504ef247ae07081857.tar.xz |
vfs: seq_file: add helpers for data filling
Add two helpers that allow access to the seq_file's own buffer, but
hide the internal details of seq_files.
This allows easier implementation of special purpose filling
functions. It also cleans up some existing functions which duplicated
the seq_file logic.
Make these inline functions in seq_file.h, as suggested by Al.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux/seq_file.h')
-rw-r--r-- | include/linux/seq_file.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 0c6a86b79596..8366d8f12e53 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -35,6 +35,44 @@ struct seq_operations { #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, char *p, char *esc); int seq_open(struct file *, const struct seq_operations *); ssize_t seq_read(struct file *, char __user *, size_t, loff_t *); |