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: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tejun Heo
Greg Kroah-Hartman
parent
c75ec764cf
commit
58282d8dc2
127
fs/sysfs/file.c
127
fs/sysfs/file.c
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@ -25,14 +25,14 @@
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#include "sysfs.h"
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/*
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* There's one sysfs_buffer for each open file and one sysfs_open_dirent
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* There's one sysfs_open_file for each open file and one sysfs_open_dirent
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* for each sysfs_dirent with one or more open files.
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*
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* sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open is
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* protected by sysfs_open_dirent_lock.
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*
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* filp->private_data points to sysfs_buffer which is chained at
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* sysfs_open_dirent->buffers, which is protected by sysfs_open_file_mutex.
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* filp->private_data points to sysfs_open_file which is chained at
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* sysfs_open_dirent->files, which is protected by sysfs_open_file_mutex.
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*/
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static DEFINE_SPINLOCK(sysfs_open_dirent_lock);
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static DEFINE_MUTEX(sysfs_open_file_mutex);
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@ -41,10 +41,10 @@ struct sysfs_open_dirent {
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atomic_t refcnt;
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atomic_t event;
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wait_queue_head_t poll;
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struct list_head buffers; /* goes through sysfs_buffer.list */
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struct list_head files; /* goes through sysfs_open_file.list */
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};
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struct sysfs_buffer {
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struct sysfs_open_file {
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size_t count;
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char *page;
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struct mutex mutex;
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@ -75,7 +75,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd)
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* This is called only once, on the file's first read unless an error
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* is returned.
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*/
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static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
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static int fill_read_buffer(struct dentry *dentry, struct sysfs_open_file *of)
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{
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struct sysfs_dirent *attr_sd = dentry->d_fsdata;
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struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
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@ -83,19 +83,19 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
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int ret = 0;
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ssize_t count;
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if (!buffer->page)
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buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
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if (!buffer->page)
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if (!of->page)
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of->page = (char *) get_zeroed_page(GFP_KERNEL);
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if (!of->page)
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return -ENOMEM;
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/* need attr_sd for attr and ops, its parent for kobj */
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if (!sysfs_get_active(attr_sd))
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return -ENODEV;
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buffer->event = atomic_read(&attr_sd->s_attr.open->event);
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of->event = atomic_read(&attr_sd->s_attr.open->event);
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ops = sysfs_file_ops(attr_sd);
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count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);
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count = ops->show(kobj, attr_sd->s_attr.attr, of->page);
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sysfs_put_active(attr_sd);
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@ -110,7 +110,7 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
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count = PAGE_SIZE - 1;
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}
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if (count >= 0)
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buffer->count = count;
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of->count = count;
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else
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ret = count;
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return ret;
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@ -138,63 +138,62 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
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static ssize_t
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sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
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{
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struct sysfs_buffer *buffer = file->private_data;
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struct sysfs_open_file *of = file->private_data;
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ssize_t retval = 0;
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mutex_lock(&buffer->mutex);
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mutex_lock(&of->mutex);
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/*
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* Fill on zero offset and the first read so that silly things like
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* "dd bs=1 skip=N" can work on sysfs files.
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*/
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if (*ppos == 0 || !buffer->page) {
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retval = fill_read_buffer(file->f_path.dentry, buffer);
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if (*ppos == 0 || !of->page) {
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retval = fill_read_buffer(file->f_path.dentry, of);
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if (retval)
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goto out;
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}
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pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
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__func__, count, *ppos, buffer->page);
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retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
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buffer->count);
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__func__, count, *ppos, of->page);
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retval = simple_read_from_buffer(buf, count, ppos, of->page, of->count);
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out:
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mutex_unlock(&buffer->mutex);
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mutex_unlock(&of->mutex);
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return retval;
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}
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/**
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* fill_write_buffer - copy buffer from userspace.
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* @buffer: data buffer for file.
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* @of: open file struct.
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* @buf: data from user.
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* @count: number of bytes in @userbuf.
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*
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* Allocate @buffer->page if it hasn't been already, then
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* copy the user-supplied buffer into it.
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* Allocate @of->page if it hasn't been already, then copy the
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* user-supplied buffer into it.
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*/
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static int fill_write_buffer(struct sysfs_buffer *buffer,
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static int fill_write_buffer(struct sysfs_open_file *of,
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const char __user *buf, size_t count)
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{
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int error;
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if (!buffer->page)
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buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
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if (!buffer->page)
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if (!of->page)
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of->page = (char *)get_zeroed_page(GFP_KERNEL);
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if (!of->page)
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return -ENOMEM;
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if (count >= PAGE_SIZE)
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count = PAGE_SIZE - 1;
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error = copy_from_user(buffer->page, buf, count);
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error = copy_from_user(of->page, buf, count);
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/*
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* If buf is assumed to contain a string, terminate it by \0, so
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* e.g. sscanf() can scan the string easily.
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*/
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buffer->page[count] = 0;
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of->page[count] = 0;
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return error ? -EFAULT : count;
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}
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/**
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* flush_write_buffer - push buffer to kobject.
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* @dentry: dentry to the attribute
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* @buffer: data buffer for file.
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* @of: open file
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* @count: number of bytes
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*
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* Get the correct pointers for the kobject and the attribute we're
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@ -202,7 +201,7 @@ static int fill_write_buffer(struct sysfs_buffer *buffer,
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* passing the buffer that we acquired in fill_write_buffer().
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*/
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static int flush_write_buffer(struct dentry *dentry,
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struct sysfs_buffer *buffer, size_t count)
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struct sysfs_open_file *of, size_t count)
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{
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struct sysfs_dirent *attr_sd = dentry->d_fsdata;
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struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
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@ -214,7 +213,7 @@ static int flush_write_buffer(struct dentry *dentry,
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return -ENODEV;
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ops = sysfs_file_ops(attr_sd);
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rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count);
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rc = ops->store(kobj, attr_sd->s_attr.attr, of->page, count);
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sysfs_put_active(attr_sd);
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@ -240,27 +239,26 @@ static int flush_write_buffer(struct dentry *dentry,
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static ssize_t sysfs_write_file(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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struct sysfs_buffer *buffer = file->private_data;
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struct sysfs_open_file *of = file->private_data;
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ssize_t len;
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mutex_lock(&buffer->mutex);
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len = fill_write_buffer(buffer, buf, count);
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mutex_lock(&of->mutex);
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len = fill_write_buffer(of, buf, count);
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if (len > 0)
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len = flush_write_buffer(file->f_path.dentry, buffer, len);
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len = flush_write_buffer(file->f_path.dentry, of, len);
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if (len > 0)
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*ppos += len;
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mutex_unlock(&buffer->mutex);
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mutex_unlock(&of->mutex);
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return len;
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}
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/**
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* sysfs_get_open_dirent - get or create sysfs_open_dirent
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* @sd: target sysfs_dirent
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* @buffer: sysfs_buffer for this instance of open
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* @of: sysfs_open_file for this instance of open
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*
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* If @sd->s_attr.open exists, increment its reference count;
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* otherwise, create one. @buffer is chained to the buffers
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* list.
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* otherwise, create one. @of is chained to the files list.
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*
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* LOCKING:
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* Kernel thread context (may sleep).
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@ -269,7 +267,7 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *buf,
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* 0 on success, -errno on failure.
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*/
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static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
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struct sysfs_buffer *buffer)
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struct sysfs_open_file *of)
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{
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struct sysfs_open_dirent *od, *new_od = NULL;
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@ -285,7 +283,7 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
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od = sd->s_attr.open;
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if (od) {
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atomic_inc(&od->refcnt);
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list_add_tail(&buffer->list, &od->buffers);
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list_add_tail(&of->list, &od->files);
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}
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spin_unlock_irq(&sysfs_open_dirent_lock);
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@ -304,23 +302,23 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
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atomic_set(&new_od->refcnt, 0);
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atomic_set(&new_od->event, 1);
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init_waitqueue_head(&new_od->poll);
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INIT_LIST_HEAD(&new_od->buffers);
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INIT_LIST_HEAD(&new_od->files);
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goto retry;
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}
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/**
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* sysfs_put_open_dirent - put sysfs_open_dirent
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* @sd: target sysfs_dirent
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* @buffer: associated sysfs_buffer
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* @of: associated sysfs_open_file
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*
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* Put @sd->s_attr.open and unlink @buffer from the buffers list.
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* If reference count reaches zero, disassociate and free it.
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* Put @sd->s_attr.open and unlink @of from the files list. If
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* reference count reaches zero, disassociate and free it.
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*
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* LOCKING:
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* None.
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*/
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static void sysfs_put_open_dirent(struct sysfs_dirent *sd,
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struct sysfs_buffer *buffer)
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struct sysfs_open_file *of)
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{
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struct sysfs_open_dirent *od = sd->s_attr.open;
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unsigned long flags;
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@ -328,7 +326,7 @@ static void sysfs_put_open_dirent(struct sysfs_dirent *sd,
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mutex_lock(&sysfs_open_file_mutex);
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spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
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list_del(&buffer->list);
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list_del(&of->list);
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if (atomic_dec_and_test(&od->refcnt))
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sd->s_attr.open = NULL;
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else
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@ -344,7 +342,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
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{
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struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
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struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
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struct sysfs_buffer *buffer;
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struct sysfs_open_file *of;
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const struct sysfs_ops *ops;
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int error = -EACCES;
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@ -377,19 +375,20 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
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goto err_out;
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}
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/* No error? Great, allocate a buffer for the file, and store it
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* it in file->private_data for easy access.
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/*
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* No error? Great, allocate a sysfs_open_file for the file, and
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* store it it in file->private_data for easy access.
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*/
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error = -ENOMEM;
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buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL);
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if (!buffer)
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of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL);
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if (!of)
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goto err_out;
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mutex_init(&buffer->mutex);
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file->private_data = buffer;
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mutex_init(&of->mutex);
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file->private_data = of;
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/* make sure we have open dirent struct */
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error = sysfs_get_open_dirent(attr_sd, buffer);
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error = sysfs_get_open_dirent(attr_sd, of);
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if (error)
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goto err_free;
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@ -398,7 +397,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
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return 0;
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err_free:
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kfree(buffer);
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kfree(of);
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err_out:
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sysfs_put_active(attr_sd);
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return error;
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@ -407,13 +406,13 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
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static int sysfs_release(struct inode *inode, struct file *filp)
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{
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struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata;
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struct sysfs_buffer *buffer = filp->private_data;
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struct sysfs_open_file *of = filp->private_data;
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sysfs_put_open_dirent(sd, buffer);
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sysfs_put_open_dirent(sd, of);
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if (buffer->page)
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free_page((unsigned long)buffer->page);
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kfree(buffer);
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if (of->page)
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free_page((unsigned long)of->page);
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kfree(of);
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return 0;
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}
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@ -433,7 +432,7 @@ static int sysfs_release(struct inode *inode, struct file *filp)
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*/
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static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
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{
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struct sysfs_buffer *buffer = filp->private_data;
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struct sysfs_open_file *of = filp->private_data;
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struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
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struct sysfs_open_dirent *od = attr_sd->s_attr.open;
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@ -445,7 +444,7 @@ static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
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sysfs_put_active(attr_sd);
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if (buffer->event != atomic_read(&od->event))
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if (of->event != atomic_read(&od->event))
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goto trigger;
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return DEFAULT_POLLMASK;
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