[ALSA] Make buffer size of proc text interface variable

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

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/include/sound/info.h b/include/sound/info.h
index f23d838..4812843 100644 (file)
--- a/include/sound/info.h
+++ b/include/sound/info.h
@@ -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 */
 };

diff --git a/sound/core/info.c b/sound/core/info.c
index 9c28853..8636683 100644 (file)
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -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>
@@ -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
@@ -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;
@@ -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;
@@ -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)
@@ -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;
@@ -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 */
@@ -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:
@@ -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) {
@@ -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;
@@ -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;
@@ -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);