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Commit 44c3eea6 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

Merge branch 'driver-core-linus' into driver-core-next 



We need those sysfs fixes in this branch to make testing, and future
patches apply properly.

Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parents 5d60418e 81440e73

fs/sysfs/file.c

+20 −2
Original line number Diff line number Diff line
@@ -609,7 +609,7 @@ 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_open_file *of;

	bool has_read, has_write;

	bool has_read, has_write, has_mmap;

	int error = -EACCES;



	/* need attr_sd for attr and ops, its parent for kobj */
@@ -621,6 +621,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) 


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

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

		has_mmap = battr->mmap;

	} else {

		const struct sysfs_ops *ops = sysfs_file_ops(attr_sd);
@@ -632,6 +633,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) 


		has_read = ops->show;

		has_write = ops->store;

		has_mmap = false;

	}



	/* check perms and supported operations */
@@ -649,7 +651,23 @@ static int sysfs_open_file(struct inode *inode, struct file *file) 
	if (!of)

		goto err_out;



	/*

	 * The following is done to give a different lockdep key to

	 * @of->mutex for files which implement mmap.  This is a rather

	 * crude way to avoid false positive lockdep warning around

	 * mm->mmap_sem - mmap nests @of->mutex under mm->mmap_sem and

	 * reading /sys/block/sda/trace/act_mask grabs sr_mutex, under

	 * which mm->mmap_sem nests, while holding @of->mutex.  As each

	 * open file has a separate mutex, it's okay as long as those don't

	 * happen on the same file.  At this point, we can't easily give

	 * each file a separate locking class.  Let's differentiate on

	 * whether the file has mmap or not for now.

	 */

	if (has_mmap)

		mutex_init(&of->mutex);

	else

		mutex_init(&of->mutex);



	of->sd = attr_sd;

	of->file = file;