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Commit 01cb06a4 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
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tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions 

Add two helper functions; seq_buf_get_buf() and seq_buf_commit() that
are used by seq_buf_path(). This makes the code similar to the
seq_file: seq_path() function, and will help to be able to consolidate
the functions between seq_file and trace_seq.

Link: http://lkml.kernel.org/r/20141104160222.644881406@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.977571447@goodmis.org



Tested-by: default avatarJiri Kosina <jkosina@suse.cz>
Acked-by: default avatarJiri Kosina <jkosina@suse.cz>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.cz>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 8cd709ae

include/linux/seq_buf.h

+41 −0
Original line number Diff line number Diff line
@@ -70,6 +70,47 @@ static inline unsigned int seq_buf_used(struct seq_buf *s) 
	return min(s->len, s->size);

}



/**

 * seq_buf_get_buf - get buffer to write arbitrary data to

 * @s: the seq_buf 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_buf_get_buf(struct seq_buf *s, char **bufp)

{

	WARN_ON(s->len > s->size + 1);



	if (s->len < s->size) {

		*bufp = s->buffer + s->len;

		return s->size - s->len;

	}



	*bufp = NULL;

	return 0;

}



/**

 * seq_buf_commit - commit data to the buffer

 * @s: the seq_buf 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_buf_commit(struct seq_buf *s, int num)

{

	if (num < 0) {

		seq_buf_set_overflow(s);

	} else {

		/* num must be negative on overflow */

		BUG_ON(s->len + num > s->size);

		s->len += num;

	}

}



extern __printf(2, 3)

int seq_buf_printf(struct seq_buf *s, const char *fmt, ...);

extern __printf(2, 0)

kernel/trace/seq_buf.c

+3 −4
Original line number Diff line number Diff line
@@ -293,8 +293,8 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, 
 */

int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc)

{

	char *buf = s->buffer + s->len;

	size_t size = seq_buf_buffer_left(s);

	char *buf;

	size_t size = seq_buf_get_buf(s, &buf);

	int res = -1;



	WARN_ON(s->size == 0);
@@ -307,8 +307,7 @@ int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc) 
				res = end - buf;

		}

	}

	if (res > 0)

		s->len += res;

	seq_buf_commit(s, res);



	return res;

}