[net-next-2.6.git] / fs / seq_file.c

/*
 * linux/fs/seq_file.c
 *
 * helper functions for making synthetic files from sequences of records.
 * initial implementation -- AV, Oct 2001.
 */

#include <linux/fs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/slab.h>

#include <asm/uaccess.h>
#include <asm/page.h>

/**
 *	seq_open -	initialize sequential file
 *	@file: file we initialize
 *	@op: method table describing the sequence
 *
 *	seq_open() sets @file, associating it with a sequence described
 *	by @op.  @op->start() sets the iterator up and returns the first
 *	element of sequence. @op->stop() shuts it down.  @op->next()
 *	returns the next element of sequence.  @op->show() prints element
 *	into the buffer.  In case of error ->start() and ->next() return
 *	ERR_PTR(error).  In the end of sequence they return %NULL. ->show()
 *	returns 0 in case of success and negative number in case of error.
 */
int seq_open(struct file *file, struct seq_operations *op)
{
	struct seq_file *p = kmalloc(sizeof(*p), GFP_KERNEL);
	if (!p)
		return -ENOMEM;
	memset(p, 0, sizeof(*p));
	sema_init(&p->sem, 1);
	p->op = op;
	file->private_data = p;

	/*
	 * Wrappers around seq_open(e.g. swaps_open) need to be
	 * aware of this. If they set f_version themselves, they
	 * should call seq_open first and then set f_version.
	 */
	file->f_version = 0;

	/* SEQ files support lseek, but not pread/pwrite */
	file->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
	return 0;
}
EXPORT_SYMBOL(seq_open);

/**
 *	seq_read -	->read() method for sequential files.
 *	@file: the file to read from
 *	@buf: the buffer to read to
 *	@size: the maximum number of bytes to read
 *	@ppos: the current position in the file
 *
 *	Ready-made ->f_op->read()
 */
ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
	struct seq_file *m = (struct seq_file *)file->private_data;
	size_t copied = 0;
	loff_t pos;
	size_t n;
	void *p;
	int err = 0;

	down(&m->sem);
	/*
	 * seq_file->op->..m_start/m_stop/m_next may do special actions
	 * or optimisations based on the file->f_version, so we want to
	 * pass the file->f_version to those methods.
	 *
	 * seq_file->version is just copy of f_version, and seq_file
	 * methods can treat it simply as file version.
	 * It is copied in first and copied out after all operations.
	 * It is convenient to have it as  part of structure to avoid the
	 * need of passing another argument to all the seq_file methods.
	 */
	m->version = file->f_version;
	/* grab buffer if we didn't have one */
	if (!m->buf) {
		m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
		if (!m->buf)
			goto Enomem;
	}
	/* if not empty - flush it first */
	if (m->count) {
		n = min(m->count, size);
		err = copy_to_user(buf, m->buf + m->from, n);
		if (err)
			goto Efault;
		m->count -= n;
		m->from += n;
		size -= n;
		buf += n;
		copied += n;
		if (!m->count)
			m->index++;
		if (!size)
			goto Done;
	}
	/* we need at least one record in buffer */
	while (1) {
		pos = m->index;
		p = m->op->start(m, &pos);
		err = PTR_ERR(p);
		if (!p || IS_ERR(p))
			break;
		err = m->op->show(m, p);
		if (err)
			break;
		if (m->count < m->size)
			goto Fill;
		m->op->stop(m, p);
		kfree(m->buf);
		m->buf = kmalloc(m->size <<= 1, GFP_KERNEL);
		if (!m->buf)
			goto Enomem;
		m->count = 0;
		m->version = 0;
	}
	m->op->stop(m, p);
	m->count = 0;
	goto Done;
Fill:
	/* they want more? let's try to get some more */
	while (m->count < size) {
		size_t offs = m->count;
		loff_t next = pos;
		p = m->op->next(m, p, &next);
		if (!p || IS_ERR(p)) {
			err = PTR_ERR(p);
			break;
		}
		err = m->op->show(m, p);
		if (err || m->count == m->size) {
			m->count = offs;
			break;
		}
		pos = next;
	}
	m->op->stop(m, p);
	n = min(m->count, size);
	err = copy_to_user(buf, m->buf, n);
	if (err)
		goto Efault;
	copied += n;
	m->count -= n;
	if (m->count)
		m->from = n;
	else
		pos++;
	m->index = pos;
Done:
	if (!copied)
		copied = err;
	else
		*ppos += copied;
	file->f_version = m->version;
	up(&m->sem);
	return copied;
Enomem:
	err = -ENOMEM;
	goto Done;
Efault:
	err = -EFAULT;
	goto Done;
}
EXPORT_SYMBOL(seq_read);

static int traverse(struct seq_file *m, loff_t offset)
{
	loff_t pos = 0;
	int error = 0;
	void *p;

	m->version = 0;
	m->index = 0;
	m->count = m->from = 0;
	if (!offset)
		return 0;
	if (!m->buf) {
		m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
		if (!m->buf)
			return -ENOMEM;
	}
	p = m->op->start(m, &m->index);
	while (p) {
		error = PTR_ERR(p);
		if (IS_ERR(p))
			break;
		error = m->op->show(m, p);
		if (error)
			break;
		if (m->count == m->size)
			goto Eoverflow;
		if (pos + m->count > offset) {
			m->from = offset - pos;
			m->count -= m->from;
			break;
		}
		pos += m->count;
		m->count = 0;
		if (pos == offset) {
			m->index++;
			break;
		}
		p = m->op->next(m, p, &m->index);
	}
	m->op->stop(m, p);
	return error;

Eoverflow:
	m->op->stop(m, p);
	kfree(m->buf);
	m->buf = kmalloc(m->size <<= 1, GFP_KERNEL);
	return !m->buf ? -ENOMEM : -EAGAIN;
}

/**
 *	seq_lseek -	->llseek() method for sequential files.
 *	@file: the file in question
 *	@offset: new position
 *	@origin: 0 for absolute, 1 for relative position
 *
 *	Ready-made ->f_op->llseek()
 */
loff_t seq_lseek(struct file *file, loff_t offset, int origin)
{
	struct seq_file *m = (struct seq_file *)file->private_data;
	long long retval = -EINVAL;

	down(&m->sem);
	m->version = file->f_version;
	switch (origin) {
		case 1:
			offset += file->f_pos;
		case 0:
			if (offset < 0)
				break;
			retval = offset;
			if (offset != file->f_pos) {
				while ((retval=traverse(m, offset)) == -EAGAIN)
					;
				if (retval) {
					/* with extreme prejudice... */
					file->f_pos = 0;
					m->version = 0;
					m->index = 0;
					m->count = 0;
				} else {
					retval = file->f_pos = offset;
				}
			}
	}
	up(&m->sem);
	file->f_version = m->version;
	return retval;
}
EXPORT_SYMBOL(seq_lseek);

/**
 *	seq_release -	free the structures associated with sequential file.
 *	@file: file in question
 *	@inode: file->f_dentry->d_inode
 *
 *	Frees the structures associated with sequential file; can be used
 *	as ->f_op->release() if you don't have private data to destroy.
 */
int seq_release(struct inode *inode, struct file *file)
{
	struct seq_file *m = (struct seq_file *)file->private_data;
	kfree(m->buf);
	kfree(m);
	return 0;
}
EXPORT_SYMBOL(seq_release);

/**
 *	seq_escape -	print string into buffer, escaping some characters
 *	@m:	target buffer
 *	@s:	string
 *	@esc:	set of characters that need escaping
 *
 *	Puts string into buffer, replacing each occurrence of character from
 *	@esc with usual octal escape.  Returns 0 in case of success, -1 - in
 *	case of overflow.
 */
int seq_escape(struct seq_file *m, const char *s, const char *esc)
{
	char *end = m->buf + m->size;
        char *p;
	char c;

        for (p = m->buf + m->count; (c = *s) != '\0' && p < end; s++) {
		if (!strchr(esc, c)) {
			*p++ = c;
			continue;
		}
		if (p + 3 < end) {
			*p++ = '\\';
			*p++ = '0' + ((c & 0300) >> 6);
			*p++ = '0' + ((c & 070) >> 3);
			*p++ = '0' + (c & 07);
			continue;
		}
		m->count = m->size;
		return -1;
        }
	m->count = p - m->buf;
        return 0;
}
EXPORT_SYMBOL(seq_escape);

int seq_printf(struct seq_file *m, const char *f, ...)
{
	va_list args;
	int len;

	if (m->count < m->size) {
		va_start(args, f);
		len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
		va_end(args);
		if (m->count + len < m->size) {
			m->count += len;
			return 0;
		}
	}
	m->count = m->size;
	return -1;
}
EXPORT_SYMBOL(seq_printf);

int seq_path(struct seq_file *m,
	     struct vfsmount *mnt, struct dentry *dentry,
	     char *esc)
{
	if (m->count < m->size) {
		char *s = m->buf + m->count;
		char *p = d_path(dentry, mnt, s, m->size - m->count);
		if (!IS_ERR(p)) {
			while (s <= p) {
				char c = *p++;
				if (!c) {
					p = m->buf + m->count;
					m->count = s - m->buf;
					return s - p;
				} else if (!strchr(esc, c)) {
					*s++ = c;
				} else if (s + 4 > p) {
					break;
				} else {
					*s++ = '\\';
					*s++ = '0' + ((c & 0300) >> 6);
					*s++ = '0' + ((c & 070) >> 3);
					*s++ = '0' + (c & 07);
				}
			}
		}
	}
	m->count = m->size;
	return -1;
}
EXPORT_SYMBOL(seq_path);

static void *single_start(struct seq_file *p, loff_t *pos)
{
	return NULL + (*pos == 0);
}

static void *single_next(struct seq_file *p, void *v, loff_t *pos)
{
	++*pos;
	return NULL;
}

static void single_stop(struct seq_file *p, void *v)
{
}

int single_open(struct file *file, int (*show)(struct seq_file *, void *),
		void *data)
{
	struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL);
	int res = -ENOMEM;

	if (op) {
		op->start = single_start;
		op->next = single_next;
		op->stop = single_stop;
		op->show = show;
		res = seq_open(file, op);
		if (!res)
			((struct seq_file *)file->private_data)->private = data;
		else
			kfree(op);
	}
	return res;
}
EXPORT_SYMBOL(single_open);

int single_release(struct inode *inode, struct file *file)
{
	struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
	int res = seq_release(inode, file);
	kfree(op);
	return res;
}
EXPORT_SYMBOL(single_release);

int seq_release_private(struct inode *inode, struct file *file)
{
	struct seq_file *seq = file->private_data;

	kfree(seq->private);
	seq->private = NULL;
	return seq_release(inode, file);
}
EXPORT_SYMBOL(seq_release_private);

int seq_putc(struct seq_file *m, char c)
{
	if (m->count < m->size) {
		m->buf[m->count++] = c;
		return 0;
	}
	return -1;
}
EXPORT_SYMBOL(seq_putc);

int seq_puts(struct seq_file *m, const char *s)
{
	int len = strlen(s);
	if (m->count + len < m->size) {
		memcpy(m->buf + m->count, s, len);
		m->count += len;
		return 0;
	}
	m->count = m->size;
	return -1;
}
EXPORT_SYMBOL(seq_puts);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/seq_file.c
	3	*
	4	* helper functions for making synthetic files from sequences of records.
	5	* initial implementation -- AV, Oct 2001.
	6	*/
	7
	8	#include <linux/fs.h>
	9	#include <linux/module.h>
	10	#include <linux/seq_file.h>
	11	#include <linux/slab.h>
	12
	13	#include <asm/uaccess.h>
	14	#include <asm/page.h>
	15
	16	/**
	17	* seq_open - initialize sequential file
	18	* @file: file we initialize
	19	* @op: method table describing the sequence
	20	*
	21	* seq_open() sets @file, associating it with a sequence described
	22	* by @op. @op->start() sets the iterator up and returns the first
	23	* element of sequence. @op->stop() shuts it down. @op->next()
	24	* returns the next element of sequence. @op->show() prints element
	25	* into the buffer. In case of error ->start() and ->next() return
	26	* ERR_PTR(error). In the end of sequence they return %NULL. ->show()
	27	* returns 0 in case of success and negative number in case of error.
	28	*/
	29	int seq_open(struct file file, struct seq_operations op)
	30	{
	31	struct seq_file p = kmalloc(sizeof(p), GFP_KERNEL);
	32	if (!p)
	33	return -ENOMEM;
	34	memset(p, 0, sizeof(*p));
	35	sema_init(&p->sem, 1);
	36	p->op = op;
	37	file->private_data = p;
	38
	39	/*
	40	* Wrappers around seq_open(e.g. swaps_open) need to be
	41	* aware of this. If they set f_version themselves, they
	42	* should call seq_open first and then set f_version.
	43	*/
	44	file->f_version = 0;
	45
	46	/* SEQ files support lseek, but not pread/pwrite */
	47	file->f_mode &= ~(FMODE_PREAD \| FMODE_PWRITE);
	48	return 0;
	49	}
	50	EXPORT_SYMBOL(seq_open);
	51
	52	/**
	53	* seq_read - ->read() method for sequential files.
67be2dd1 MW	54	* @file: the file to read from
	55	* @buf: the buffer to read to
	56	* @size: the maximum number of bytes to read
	57	* @ppos: the current position in the file
1da177e4 LT	58	*
	59	* Ready-made ->f_op->read()
	60	*/
	61	ssize_t seq_read(struct file file, char __user buf, size_t size, loff_t *ppos)
	62	{
	63	struct seq_file m = (struct seq_file )file->private_data;
	64	size_t copied = 0;
	65	loff_t pos;
	66	size_t n;
	67	void *p;
	68	int err = 0;
	69
	70	down(&m->sem);
	71	/*
	72	* seq_file->op->..m_start/m_stop/m_next may do special actions
	73	* or optimisations based on the file->f_version, so we want to
	74	* pass the file->f_version to those methods.
	75	*
	76	* seq_file->version is just copy of f_version, and seq_file
	77	* methods can treat it simply as file version.
	78	* It is copied in first and copied out after all operations.
	79	* It is convenient to have it as part of structure to avoid the
	80	* need of passing another argument to all the seq_file methods.
	81	*/
	82	m->version = file->f_version;
	83	/* grab buffer if we didn't have one */
	84	if (!m->buf) {
	85	m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
	86	if (!m->buf)
	87	goto Enomem;
	88	}
	89	/* if not empty - flush it first */
	90	if (m->count) {
	91	n = min(m->count, size);
	92	err = copy_to_user(buf, m->buf + m->from, n);
	93	if (err)
	94	goto Efault;
	95	m->count -= n;
	96	m->from += n;
	97	size -= n;
	98	buf += n;
	99	copied += n;
	100	if (!m->count)
	101	m->index++;
	102	if (!size)
	103	goto Done;
	104	}
	105	/* we need at least one record in buffer */
	106	while (1) {
	107	pos = m->index;
	108	p = m->op->start(m, &pos);
	109	err = PTR_ERR(p);
	110	if (!p \|\| IS_ERR(p))
	111	break;
	112	err = m->op->show(m, p);
	113	if (err)
	114	break;
	115	if (m->count < m->size)
	116	goto Fill;
	117	m->op->stop(m, p);
	118	kfree(m->buf);
	119	m->buf = kmalloc(m->size <<= 1, GFP_KERNEL);
	120	if (!m->buf)
	121	goto Enomem;
122	m->count = 0;
123	m->version = 0;
124	}
125	m->op->stop(m, p);
126	m->count = 0;
127	goto Done;
128	Fill:
129	/* they want more? let's try to get some more */
130	while (m->count < size) {
131	size_t offs = m->count;
132	loff_t next = pos;
133	p = m->op->next(m, p, &next);
134	if (!p \|\| IS_ERR(p)) {
135	err = PTR_ERR(p);
136	break;
137	}
138	err = m->op->show(m, p);
139	if (err \|\| m->count == m->size) {
140	m->count = offs;
141	break;
142	}
143	pos = next;
144	}
145	m->op->stop(m, p);
146	n = min(m->count, size);
147	err = copy_to_user(buf, m->buf, n);
148	if (err)
149	goto Efault;
150	copied += n;
151	m->count -= n;
152	if (m->count)
153	m->from = n;
154	else
155	pos++;
156	m->index = pos;
157	Done:
158	if (!copied)
159	copied = err;
160	else
161	*ppos += copied;
162	file->f_version = m->version;
163	up(&m->sem);
164	return copied;
165	Enomem:
166	err = -ENOMEM;
167	goto Done;
168	Efault:
169	err = -EFAULT;
170	goto Done;
171	}
172	EXPORT_SYMBOL(seq_read);
173
174	static int traverse(struct seq_file *m, loff_t offset)
175	{
176	loff_t pos = 0;
177	int error = 0;
178	void *p;
179
180	m->version = 0;
181	m->index = 0;
182	m->count = m->from = 0;
183	if (!offset)
184	return 0;
185	if (!m->buf) {
186	m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
187	if (!m->buf)
188	return -ENOMEM;
189	}
190	p = m->op->start(m, &m->index);
191	while (p) {
192	error = PTR_ERR(p);
193	if (IS_ERR(p))
194	break;
195	error = m->op->show(m, p);
196	if (error)
197	break;
198	if (m->count == m->size)
199	goto Eoverflow;
200	if (pos + m->count > offset) {
201	m->from = offset - pos;
202	m->count -= m->from;
203	break;
204	}
205	pos += m->count;
206	m->count = 0;
207	if (pos == offset) {
208	m->index++;
209	break;
210	}
211	p = m->op->next(m, p, &m->index);
212	}
213	m->op->stop(m, p);
214	return error;
215
216	Eoverflow:
217	m->op->stop(m, p);
218	kfree(m->buf);
219	m->buf = kmalloc(m->size <<= 1, GFP_KERNEL);
220	return !m->buf ? -ENOMEM : -EAGAIN;
221	}
222
223	/**
224	* seq_lseek - ->llseek() method for sequential files.
67be2dd1 MW	225	* @file: the file in question
	226	* @offset: new position
	227	* @origin: 0 for absolute, 1 for relative position
1da177e4 LT	228	*
	229	* Ready-made ->f_op->llseek()
	230	*/
	231	loff_t seq_lseek(struct file *file, loff_t offset, int origin)
	232	{
	233	struct seq_file m = (struct seq_file )file->private_data;
	234	long long retval = -EINVAL;
	235
	236	down(&m->sem);
	237	m->version = file->f_version;
	238	switch (origin) {
	239	case 1:
	240	offset += file->f_pos;
	241	case 0:
	242	if (offset < 0)
	243	break;
	244	retval = offset;
	245	if (offset != file->f_pos) {
	246	while ((retval=traverse(m, offset)) == -EAGAIN)
	247	;
	248	if (retval) {
	249	/* with extreme prejudice... */
	250	file->f_pos = 0;
	251	m->version = 0;
	252	m->index = 0;
	253	m->count = 0;
	254	} else {
	255	retval = file->f_pos = offset;
	256	}
	257	}
	258	}
	259	up(&m->sem);
	260	file->f_version = m->version;
	261	return retval;
	262	}
	263	EXPORT_SYMBOL(seq_lseek);
	264
	265	/**
	266	* seq_release - free the structures associated with sequential file.
	267	* @file: file in question
	268	* @inode: file->f_dentry->d_inode
	269	*
	270	* Frees the structures associated with sequential file; can be used
	271	* as ->f_op->release() if you don't have private data to destroy.
	272	*/
	273	int seq_release(struct inode inode, struct file file)
	274	{
	275	struct seq_file m = (struct seq_file )file->private_data;
	276	kfree(m->buf);
	277	kfree(m);
	278	return 0;
	279	}
	280	EXPORT_SYMBOL(seq_release);
	281
	282	/**
	283	* seq_escape - print string into buffer, escaping some characters
	284	* @m: target buffer
	285	* @s: string
	286	* @esc: set of characters that need escaping
	287	*
	288	* Puts string into buffer, replacing each occurrence of character from
	289	* @esc with usual octal escape. Returns 0 in case of success, -1 - in
	290	* case of overflow.
	291	*/
292	int seq_escape(struct seq_file m, const char s, const char *esc)
293	{
294	char *end = m->buf + m->size;
295	char *p;
296	char c;
297
298	for (p = m->buf + m->count; (c = *s) != '\0' && p < end; s++) {
299	if (!strchr(esc, c)) {
300	*p++ = c;
301	continue;
302	}
303	if (p + 3 < end) {
304	*p++ = '\\';
305	*p++ = '0' + ((c & 0300) >> 6);
306	*p++ = '0' + ((c & 070) >> 3);
307	*p++ = '0' + (c & 07);
308	continue;
309	}
310	m->count = m->size;
311	return -1;
312	}
313	m->count = p - m->buf;
314	return 0;
315	}
316	EXPORT_SYMBOL(seq_escape);
317
318	int seq_printf(struct seq_file m, const char f, ...)
319	{
320	va_list args;
321	int len;
322
323	if (m->count < m->size) {
324	va_start(args, f);
325	len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
326	va_end(args);
327	if (m->count + len < m->size) {
328	m->count += len;
329	return 0;
330	}
331	}
332	m->count = m->size;
333	return -1;
334	}
335	EXPORT_SYMBOL(seq_printf);
336
337	int seq_path(struct seq_file *m,
338	struct vfsmount mnt, struct dentry dentry,
339	char *esc)
340	{
341	if (m->count < m->size) {
342	char *s = m->buf + m->count;
343	char *p = d_path(dentry, mnt, s, m->size - m->count);
344	if (!IS_ERR(p)) {
345	while (s <= p) {
346	char c = *p++;
347	if (!c) {
348	p = m->buf + m->count;
349	m->count = s - m->buf;
350	return s - p;
351	} else if (!strchr(esc, c)) {
352	*s++ = c;
353	} else if (s + 4 > p) {
354	break;
355	} else {
356	*s++ = '\\';
357	*s++ = '0' + ((c & 0300) >> 6);
358	*s++ = '0' + ((c & 070) >> 3);
359	*s++ = '0' + (c & 07);
360	}
361	}
362	}
363	}
364	m->count = m->size;
365	return -1;
366	}
367	EXPORT_SYMBOL(seq_path);
368
369	static void single_start(struct seq_file p, loff_t *pos)
370	{
371	return NULL + (*pos == 0);
372	}
373
374	static void single_next(struct seq_file p, void v, loff_t pos)
375	{
376	++*pos;
377	return NULL;
378	}
379
380	static void single_stop(struct seq_file p, void v)
381	{
382	}
383
384	int single_open(struct file file, int (show)(struct seq_file , void ),
385	void *data)
386	{
387	struct seq_operations op = kmalloc(sizeof(op), GFP_KERNEL);
388	int res = -ENOMEM;
389
390	if (op) {
391	op->start = single_start;
392	op->next = single_next;
393	op->stop = single_stop;
394	op->show = show;
395	res = seq_open(file, op);
396	if (!res)
397	((struct seq_file *)file->private_data)->private = data;
398	else
399	kfree(op);
400	}
401	return res;
402	}
403	EXPORT_SYMBOL(single_open);
404
405	int single_release(struct inode inode, struct file file)
406	{
407	struct seq_operations op = ((struct seq_file )file->private_data)->op;
408	int res = seq_release(inode, file);
409	kfree(op);
410	return res;
411	}
412	EXPORT_SYMBOL(single_release);
413
414	int seq_release_private(struct inode inode, struct file file)
415	{
416	struct seq_file *seq = file->private_data;
417
418	kfree(seq->private);
419	seq->private = NULL;
420	return seq_release(inode, file);
421	}
422	EXPORT_SYMBOL(seq_release_private);
423
424	int seq_putc(struct seq_file *m, char c)
425	{
426	if (m->count < m->size) {
427	m->buf[m->count++] = c;
428	return 0;
429	}
430	return -1;
431	}
432	EXPORT_SYMBOL(seq_putc);
433
434	int seq_puts(struct seq_file m, const char s)
435	{
436	int len = strlen(s);
437	if (m->count + len < m->size) {
438	memcpy(m->buf + m->count, s, len);
439	m->count += len;
440	return 0;
441	}
442	m->count = m->size;
443	return -1;
444	}
445	EXPORT_SYMBOL(seq_puts);