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>

1 files changed, 63 insertions, 64 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 499cff8554fc..4b55bcf4422e 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -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;