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Commit 49fe6047 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
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sysfs: prepare open path for unified regular / bin file handling 



sysfs bin file handling will be merged into the regular file support.
This patch prepares the open path.

This patch updates sysfs_open_file() such that it can handle both
regular and bin files.

This is a preparation and the new bin file path isn't used yet.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 73d97146

fs/sysfs/file.c

+33 −25
Original line number Diff line number Diff line
@@ -610,37 +610,39 @@ 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_open_file *of;

	const struct sysfs_ops *ops;

	bool has_read, has_write;

	int error = -EACCES;



	/* need attr_sd for attr and ops, its parent for kobj */

	if (!sysfs_get_active(attr_sd))

		return -ENODEV;



	if (sysfs_is_bin(attr_sd)) {

		struct bin_attribute *battr = attr_sd->s_bin_attr.bin_attr;



		has_read = battr->read || battr->mmap;

		has_write = battr->write || battr->mmap;

	} else {

		const struct sysfs_ops *ops = sysfs_file_ops(attr_sd);



		/* every kobject with an attribute needs a ktype assigned */

	ops = sysfs_file_ops(attr_sd);

		if (WARN(!ops, KERN_ERR

			 "missing sysfs attribute operations for kobject: %s\n",

			 kobject_name(kobj)))

			goto err_out;



	/* File needs write support.

	 * The inode's perms must say it's ok,

	 * and we must have a store method.

	 */

	if (file->f_mode & FMODE_WRITE) {

		if (!(inode->i_mode & S_IWUGO) || !ops->store)

			goto err_out;

		has_read = ops->show;

		has_write = ops->store;

	}



	/* File needs read support.

	 * The inode's perms must say it's ok, and we there

	 * must be a show method for it.

	 */

	if (file->f_mode & FMODE_READ) {

		if (!(inode->i_mode & S_IRUGO) || !ops->show)

	/* check perms and supported operations */

	if ((file->f_mode & FMODE_WRITE) &&

	    (!(inode->i_mode & S_IWUGO) || !has_write))

		goto err_out;



	if ((file->f_mode & FMODE_READ) &&

	    (!(inode->i_mode & S_IRUGO) || !has_read))

		goto err_out;

	}



	/* allocate a sysfs_open_file for the file */

	error = -ENOMEM;
@@ -653,10 +655,13 @@ static int sysfs_open_file(struct inode *inode, struct file *file) 
	of->file = file;



	/*

	 * Always instantiate seq_file even if read access is not

	 * implemented or requested.  This unifies private data access and

	 * most files are readable anyway.

	 * Always instantiate seq_file even if read access doesn't use

	 * seq_file or is not requested.  This unifies private data access

	 * and readable regular files are the vast majority anyway.

	 */

	if (sysfs_is_bin(attr_sd))

		error = single_open(file, NULL, of);

	else

		error = single_open(file, sysfs_seq_show, of);

	if (error)

		goto err_free;
@@ -807,6 +812,9 @@ const struct file_operations sysfs_bin_operations = { 
	.write		= sysfs_write_file,

	.llseek		= generic_file_llseek,

	.mmap		= sysfs_bin_mmap,

	.open		= sysfs_open_file,

	.release	= sysfs_release,

	.poll		= sysfs_poll,

};



int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,