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[ALSA] Make buffer size of proc text interface variable
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Make the read/write buffer size of proc text interface variable.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Takashi Iwai authored and Jaroslav Kysela committed Jun 22, 2006
1 parent 2f4ca8e commit 7e4eeec
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Showing 2 changed files with 82 additions and 73 deletions.
6 changes: 3 additions & 3 deletions include/sound/info.h
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Original file line number Diff line number Diff line change
Expand Up @@ -27,9 +27,9 @@
/* buffer for information */
struct snd_info_buffer {
char *buffer; /* pointer to begin of buffer */
char *curr; /* current position in buffer */
unsigned long size; /* current size */
unsigned long len; /* total length of buffer */
unsigned int curr; /* current position in buffer */
unsigned int size; /* current size */
unsigned int len; /* total length of buffer */
int stop; /* stop flag */
int error; /* error code */
};
Expand Down
149 changes: 79 additions & 70 deletions sound/core/info.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,6 @@

#include <sound/driver.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/time.h>
#include <linux/smp_lock.h>
#include <linux/string.h>
Expand Down Expand Up @@ -82,6 +81,24 @@ static int snd_info_version_init(void);
static int snd_info_version_done(void);


/* resize the proc r/w buffer */
static int resize_info_buffer(struct snd_info_buffer *buffer,
unsigned int nsize)
{
char *nbuf;

nsize = PAGE_ALIGN(nsize);
nbuf = kmalloc(nsize, GFP_KERNEL);
if (! nbuf)
return -ENOMEM;

memcpy(nbuf, buffer->buffer, buffer->len);
kfree(buffer->buffer);
buffer->buffer = nbuf;
buffer->len = nsize;
return 0;
}

/**
* snd_iprintf - printf on the procfs buffer
* @buffer: the procfs buffer
Expand All @@ -95,17 +112,25 @@ int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
{
va_list args;
int len, res;
int err = 0;

if (buffer->stop || buffer->error)
return 0;
len = buffer->len - buffer->size;
va_start(args, fmt);
res = vsnprintf(buffer->curr, len, fmt, args);
va_end(args);
if (res >= len) {
buffer->stop = 1;
return 0;
for (;;) {
res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, args);
if (res < len)
break;
err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
if (err < 0)
break;
len = buffer->len - buffer->size;
}
va_end(args);

if (err < 0)
return err;
buffer->curr += res;
buffer->size += res;
return res;
Expand Down Expand Up @@ -225,7 +250,7 @@ static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer
struct snd_info_private_data *data;
struct snd_info_entry *entry;
struct snd_info_buffer *buf;
size_t size = 0;
ssize_t size = 0;
loff_t pos;

data = file->private_data;
Expand All @@ -241,14 +266,20 @@ static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer
buf = data->wbuffer;
if (buf == NULL)
return -EIO;
if (pos >= buf->len)
return -ENOMEM;
size = buf->len - pos;
size = min(count, size);
if (copy_from_user(buf->buffer + pos, buffer, size))
mutex_unlock(&entry->access);
if (pos + count >= buf->len) {
if (resize_info_buffer(buf, pos + count)) {
mutex_unlock(&entry->access);
return -ENOMEM;
}
}
if (copy_from_user(buf->buffer + pos, buffer, count)) {
mutex_unlock(&entry->access);
return -EFAULT;
if ((long)buf->size < pos + size)
buf->size = pos + size;
}
buf->size = pos + count;
mutex_unlock(&entry->access);
size = count;
break;
case SNDRV_INFO_CONTENT_DATA:
if (entry->c.ops->write)
Expand Down Expand Up @@ -283,18 +314,14 @@ static int snd_info_entry_open(struct inode *inode, struct file *file)
}
mode = file->f_flags & O_ACCMODE;
if (mode == O_RDONLY || mode == O_RDWR) {
if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
!entry->c.text.read_size) ||
(entry->content == SNDRV_INFO_CONTENT_DATA &&
if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
entry->c.ops->read == NULL)) {
err = -ENODEV;
goto __error;
}
}
if (mode == O_WRONLY || mode == O_RDWR) {
if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
!entry->c.text.write_size) ||
(entry->content == SNDRV_INFO_CONTENT_DATA &&
if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
entry->c.ops->write == NULL)) {
err = -ENODEV;
goto __error;
Expand All @@ -310,49 +337,23 @@ static int snd_info_entry_open(struct inode *inode, struct file *file)
case SNDRV_INFO_CONTENT_TEXT:
if (mode == O_RDONLY || mode == O_RDWR) {
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (buffer == NULL) {
kfree(data);
err = -ENOMEM;
goto __error;
}
buffer->len = (entry->c.text.read_size +
(PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
buffer->buffer = vmalloc(buffer->len);
if (buffer->buffer == NULL) {
kfree(buffer);
kfree(data);
err = -ENOMEM;
goto __error;
}
buffer->curr = buffer->buffer;
if (buffer == NULL)
goto __nomem;
data->rbuffer = buffer;
buffer->len = PAGE_SIZE;
buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
if (buffer->buffer == NULL)
goto __nomem;
}
if (mode == O_WRONLY || mode == O_RDWR) {
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (buffer == NULL) {
if (mode == O_RDWR) {
vfree(data->rbuffer->buffer);
kfree(data->rbuffer);
}
kfree(data);
err = -ENOMEM;
goto __error;
}
buffer->len = (entry->c.text.write_size +
(PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
buffer->buffer = vmalloc(buffer->len);
if (buffer->buffer == NULL) {
if (mode == O_RDWR) {
vfree(data->rbuffer->buffer);
kfree(data->rbuffer);
}
kfree(buffer);
kfree(data);
err = -ENOMEM;
goto __error;
}
buffer->curr = buffer->buffer;
if (buffer == NULL)
goto __nomem;
data->wbuffer = buffer;
buffer->len = PAGE_SIZE;
buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
if (buffer->buffer == NULL)
goto __nomem;
}
break;
case SNDRV_INFO_CONTENT_DATA: /* data */
Expand All @@ -377,6 +378,17 @@ static int snd_info_entry_open(struct inode *inode, struct file *file)
}
return 0;

__nomem:
if (data->rbuffer) {
kfree(data->rbuffer->buffer);
kfree(data->rbuffer);
}
if (data->wbuffer) {
kfree(data->wbuffer->buffer);
kfree(data->wbuffer);
}
kfree(data);
err = -ENOMEM;
__error:
module_put(entry->module);
__error1:
Expand All @@ -395,11 +407,11 @@ static int snd_info_entry_release(struct inode *inode, struct file *file)
entry = data->entry;
switch (entry->content) {
case SNDRV_INFO_CONTENT_TEXT:
if (mode == O_RDONLY || mode == O_RDWR) {
vfree(data->rbuffer->buffer);
if (data->rbuffer) {
kfree(data->rbuffer->buffer);
kfree(data->rbuffer);
}
if (mode == O_WRONLY || mode == O_RDWR) {
if (data->wbuffer) {
if (entry->c.text.write) {
entry->c.text.write(entry, data->wbuffer);
if (data->wbuffer->error) {
Expand All @@ -408,7 +420,7 @@ static int snd_info_entry_release(struct inode *inode, struct file *file)
data->wbuffer->error);
}
}
vfree(data->wbuffer->buffer);
kfree(data->wbuffer->buffer);
kfree(data->wbuffer);
}
break;
Expand Down Expand Up @@ -668,24 +680,22 @@ int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
if (len <= 0 || buffer->stop || buffer->error)
return 1;
while (--len > 0) {
c = *buffer->curr++;
c = buffer->buffer[buffer->curr++];
if (c == '\n') {
if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
if (buffer->curr >= buffer->size)
buffer->stop = 1;
}
break;
}
*line++ = c;
if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
if (buffer->curr >= buffer->size) {
buffer->stop = 1;
break;
}
}
while (c != '\n' && !buffer->stop) {
c = *buffer->curr++;
if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
c = buffer->buffer[buffer->curr++];
if (buffer->curr >= buffer->size)
buffer->stop = 1;
}
}
*line = '\0';
return 0;
Expand Down Expand Up @@ -978,7 +988,6 @@ static int __init snd_info_version_init(void)
entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
if (entry == NULL)
return -ENOMEM;
entry->c.text.read_size = 256;
entry->c.text.read = snd_info_version_read;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
Expand Down

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