Commit 58282d8d authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
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sysfs: rename sysfs_buffer to sysfs_open_file



sysfs read path will be converted to use seq_file which will handle
buffering making sysfs_buffer a misnomer.  Rename sysfs_buffer to
sysfs_open_file, and sysfs_open_dirent->buffers to ->files.

This path is pure rename.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c75ec764
......@@ -25,14 +25,14 @@
#include "sysfs.h"
/*
* There's one sysfs_buffer for each open file and one sysfs_open_dirent
* There's one sysfs_open_file for each open file and one sysfs_open_dirent
* for each sysfs_dirent with one or more open files.
*
* sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open is
* protected by sysfs_open_dirent_lock.
*
* filp->private_data points to sysfs_buffer which is chained at
* sysfs_open_dirent->buffers, which is protected by sysfs_open_file_mutex.
* filp->private_data points to sysfs_open_file which is chained at
* sysfs_open_dirent->files, which is protected by sysfs_open_file_mutex.
*/
static DEFINE_SPINLOCK(sysfs_open_dirent_lock);
static DEFINE_MUTEX(sysfs_open_file_mutex);
......@@ -41,10 +41,10 @@ struct sysfs_open_dirent {
atomic_t refcnt;
atomic_t event;
wait_queue_head_t poll;
struct list_head buffers; /* goes through sysfs_buffer.list */
struct list_head files; /* goes through sysfs_open_file.list */
};
struct sysfs_buffer {
struct sysfs_open_file {
size_t count;
char *page;
struct mutex mutex;
......@@ -75,7 +75,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd)
* This is called only once, on the file's first read unless an error
* is returned.
*/
static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
static int fill_read_buffer(struct dentry *dentry, struct sysfs_open_file *of)
{
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
......@@ -83,19 +83,19 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
int ret = 0;
ssize_t count;
if (!buffer->page)
buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
if (!buffer->page)
if (!of->page)
of->page = (char *) get_zeroed_page(GFP_KERNEL);
if (!of->page)
return -ENOMEM;
/* need attr_sd for attr and ops, its parent for kobj */
if (!sysfs_get_active(attr_sd))
return -ENODEV;
buffer->event = atomic_read(&attr_sd->s_attr.open->event);
of->event = atomic_read(&attr_sd->s_attr.open->event);
ops = sysfs_file_ops(attr_sd);
count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);
count = ops->show(kobj, attr_sd->s_attr.attr, of->page);
sysfs_put_active(attr_sd);
......@@ -110,7 +110,7 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
count = PAGE_SIZE - 1;
}
if (count >= 0)
buffer->count = count;
of->count = count;
else
ret = count;
return ret;
......@@ -138,63 +138,62 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
static ssize_t
sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
struct sysfs_buffer *buffer = file->private_data;
struct sysfs_open_file *of = file->private_data;
ssize_t retval = 0;
mutex_lock(&buffer->mutex);
mutex_lock(&of->mutex);
/*
* Fill on zero offset and the first read so that silly things like
* "dd bs=1 skip=N" can work on sysfs files.
*/
if (*ppos == 0 || !buffer->page) {
retval = fill_read_buffer(file->f_path.dentry, buffer);
if (*ppos == 0 || !of->page) {
retval = fill_read_buffer(file->f_path.dentry, of);
if (retval)
goto out;
}
pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
__func__, count, *ppos, buffer->page);
retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
buffer->count);
__func__, count, *ppos, of->page);
retval = simple_read_from_buffer(buf, count, ppos, of->page, of->count);
out:
mutex_unlock(&buffer->mutex);
mutex_unlock(&of->mutex);
return retval;
}
/**
* fill_write_buffer - copy buffer from userspace.
* @buffer: data buffer for file.
* @of: open file struct.
* @buf: data from user.
* @count: number of bytes in @userbuf.
*
* Allocate @buffer->page if it hasn't been already, then
* copy the user-supplied buffer into it.
* Allocate @of->page if it hasn't been already, then copy the
* user-supplied buffer into it.
*/
static int fill_write_buffer(struct sysfs_buffer *buffer,
static int fill_write_buffer(struct sysfs_open_file *of,
const char __user *buf, size_t count)
{
int error;
if (!buffer->page)
buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
if (!buffer->page)
if (!of->page)
of->page = (char *)get_zeroed_page(GFP_KERNEL);
if (!of->page)
return -ENOMEM;
if (count >= PAGE_SIZE)
count = PAGE_SIZE - 1;
error = copy_from_user(buffer->page, buf, count);
error = copy_from_user(of->page, buf, count);
/*
* If buf is assumed to contain a string, terminate it by \0, so
* e.g. sscanf() can scan the string easily.
*/
buffer->page[count] = 0;
of->page[count] = 0;
return error ? -EFAULT : count;
}
/**
* flush_write_buffer - push buffer to kobject.
* @dentry: dentry to the attribute
* @buffer: data buffer for file.
* @of: open file
* @count: number of bytes
*
* Get the correct pointers for the kobject and the attribute we're
......@@ -202,7 +201,7 @@ static int fill_write_buffer(struct sysfs_buffer *buffer,
* passing the buffer that we acquired in fill_write_buffer().
*/
static int flush_write_buffer(struct dentry *dentry,
struct sysfs_buffer *buffer, size_t count)
struct sysfs_open_file *of, size_t count)
{
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
......@@ -214,7 +213,7 @@ static int flush_write_buffer(struct dentry *dentry,
return -ENODEV;
ops = sysfs_file_ops(attr_sd);
rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count);
rc = ops->store(kobj, attr_sd->s_attr.attr, of->page, count);
sysfs_put_active(attr_sd);
......@@ -240,27 +239,26 @@ static int flush_write_buffer(struct dentry *dentry,
static ssize_t sysfs_write_file(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct sysfs_buffer *buffer = file->private_data;
struct sysfs_open_file *of = file->private_data;
ssize_t len;
mutex_lock(&buffer->mutex);
len = fill_write_buffer(buffer, buf, count);
mutex_lock(&of->mutex);
len = fill_write_buffer(of, buf, count);
if (len > 0)
len = flush_write_buffer(file->f_path.dentry, buffer, len);
len = flush_write_buffer(file->f_path.dentry, of, len);
if (len > 0)
*ppos += len;
mutex_unlock(&buffer->mutex);
mutex_unlock(&of->mutex);
return len;
}
/**
* sysfs_get_open_dirent - get or create sysfs_open_dirent
* @sd: target sysfs_dirent
* @buffer: sysfs_buffer for this instance of open
* @of: sysfs_open_file for this instance of open
*
* If @sd->s_attr.open exists, increment its reference count;
* otherwise, create one. @buffer is chained to the buffers
* list.
* otherwise, create one. @of is chained to the files list.
*
* LOCKING:
* Kernel thread context (may sleep).
......@@ -269,7 +267,7 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *buf,
* 0 on success, -errno on failure.
*/
static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
struct sysfs_buffer *buffer)
struct sysfs_open_file *of)
{
struct sysfs_open_dirent *od, *new_od = NULL;
......@@ -285,7 +283,7 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
od = sd->s_attr.open;
if (od) {
atomic_inc(&od->refcnt);
list_add_tail(&buffer->list, &od->buffers);
list_add_tail(&of->list, &od->files);
}
spin_unlock_irq(&sysfs_open_dirent_lock);
......@@ -304,23 +302,23 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
atomic_set(&new_od->refcnt, 0);
atomic_set(&new_od->event, 1);
init_waitqueue_head(&new_od->poll);
INIT_LIST_HEAD(&new_od->buffers);
INIT_LIST_HEAD(&new_od->files);
goto retry;
}
/**
* sysfs_put_open_dirent - put sysfs_open_dirent
* @sd: target sysfs_dirent
* @buffer: associated sysfs_buffer
* @of: associated sysfs_open_file
*
* Put @sd->s_attr.open and unlink @buffer from the buffers list.
* If reference count reaches zero, disassociate and free it.
* Put @sd->s_attr.open and unlink @of from the files list. If
* reference count reaches zero, disassociate and free it.
*
* LOCKING:
* None.
*/
static void sysfs_put_open_dirent(struct sysfs_dirent *sd,
struct sysfs_buffer *buffer)
struct sysfs_open_file *of)
{
struct sysfs_open_dirent *od = sd->s_attr.open;
unsigned long flags;
......@@ -328,7 +326,7 @@ static void sysfs_put_open_dirent(struct sysfs_dirent *sd,
mutex_lock(&sysfs_open_file_mutex);
spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
list_del(&buffer->list);
list_del(&of->list);
if (atomic_dec_and_test(&od->refcnt))
sd->s_attr.open = NULL;
else
......@@ -344,7 +342,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
{
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
struct sysfs_buffer *buffer;
struct sysfs_open_file *of;
const struct sysfs_ops *ops;
int error = -EACCES;
......@@ -377,19 +375,20 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
goto err_out;
}
/* No error? Great, allocate a buffer for the file, and store it
* it in file->private_data for easy access.
/*
* No error? Great, allocate a sysfs_open_file for the file, and
* store it it in file->private_data for easy access.
*/
error = -ENOMEM;
buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL);
if (!buffer)
of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL);
if (!of)
goto err_out;
mutex_init(&buffer->mutex);
file->private_data = buffer;
mutex_init(&of->mutex);
file->private_data = of;
/* make sure we have open dirent struct */
error = sysfs_get_open_dirent(attr_sd, buffer);
error = sysfs_get_open_dirent(attr_sd, of);
if (error)
goto err_free;
......@@ -398,7 +397,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
return 0;
err_free:
kfree(buffer);
kfree(of);
err_out:
sysfs_put_active(attr_sd);
return error;
......@@ -407,13 +406,13 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
static int sysfs_release(struct inode *inode, struct file *filp)
{
struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata;
struct sysfs_buffer *buffer = filp->private_data;
struct sysfs_open_file *of = filp->private_data;
sysfs_put_open_dirent(sd, buffer);
sysfs_put_open_dirent(sd, of);
if (buffer->page)
free_page((unsigned long)buffer->page);
kfree(buffer);
if (of->page)
free_page((unsigned long)of->page);
kfree(of);
return 0;
}
......@@ -433,7 +432,7 @@ static int sysfs_release(struct inode *inode, struct file *filp)
*/
static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
{
struct sysfs_buffer *buffer = filp->private_data;
struct sysfs_open_file *of = filp->private_data;
struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
struct sysfs_open_dirent *od = attr_sd->s_attr.open;
......@@ -445,7 +444,7 @@ static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
sysfs_put_active(attr_sd);
if (buffer->event != atomic_read(&od->event))
if (of->event != atomic_read(&od->event))
goto trigger;
return DEFAULT_POLLMASK;
......
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