Commit fd5a13f4 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

proc: add a read_iter method to proc proc_ops 



This will allow proc files to implement iter read semantics.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 906146f4

fs/proc/inode.c

+50 −3
Original line number Diff line number Diff line
@@ -297,6 +297,21 @@ static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) 
	return rv;

}



static ssize_t proc_reg_read_iter(struct kiocb *iocb, struct iov_iter *iter)

{

	struct proc_dir_entry *pde = PDE(file_inode(iocb->ki_filp));

	ssize_t ret;



	if (pde_is_permanent(pde))

		return pde->proc_ops->proc_read_iter(iocb, iter);



	if (!use_pde(pde))

		return -EIO;

	ret = pde->proc_ops->proc_read_iter(iocb, iter);

	unuse_pde(pde);

	return ret;

}



static ssize_t pde_read(struct proc_dir_entry *pde, struct file *file, char __user *buf, size_t count, loff_t *ppos)

{

	typeof_member(struct proc_ops, proc_read) read;
@@ -578,6 +593,18 @@ static const struct file_operations proc_reg_file_ops = { 
	.release	= proc_reg_release,

};



static const struct file_operations proc_iter_file_ops = {

	.llseek		= proc_reg_llseek,

	.read_iter	= proc_reg_read_iter,

	.write		= proc_reg_write,

	.poll		= proc_reg_poll,

	.unlocked_ioctl	= proc_reg_unlocked_ioctl,

	.mmap		= proc_reg_mmap,

	.get_unmapped_area = proc_reg_get_unmapped_area,

	.open		= proc_reg_open,

	.release	= proc_reg_release,

};



#ifdef CONFIG_COMPAT

static const struct file_operations proc_reg_file_ops_compat = {

	.llseek		= proc_reg_llseek,
@@ -591,6 +618,19 @@ static const struct file_operations proc_reg_file_ops_compat = { 
	.open		= proc_reg_open,

	.release	= proc_reg_release,

};



static const struct file_operations proc_iter_file_ops_compat = {

	.llseek		= proc_reg_llseek,

	.read_iter	= proc_reg_read_iter,

	.write		= proc_reg_write,

	.poll		= proc_reg_poll,

	.unlocked_ioctl	= proc_reg_unlocked_ioctl,

	.compat_ioctl	= proc_reg_compat_ioctl,

	.mmap		= proc_reg_mmap,

	.get_unmapped_area = proc_reg_get_unmapped_area,

	.open		= proc_reg_open,

	.release	= proc_reg_release,

};

#endif



static void proc_put_link(void *p)
@@ -642,10 +682,17 @@ struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) 


	if (S_ISREG(inode->i_mode)) {

		inode->i_op = de->proc_iops;

		if (de->proc_ops->proc_read_iter)

			inode->i_fop = &proc_iter_file_ops;

		else

			inode->i_fop = &proc_reg_file_ops;

#ifdef CONFIG_COMPAT

		if (de->proc_ops->proc_compat_ioctl)

		if (de->proc_ops->proc_compat_ioctl) {

			if (de->proc_ops->proc_read_iter)

				inode->i_fop = &proc_iter_file_ops_compat;

			else

				inode->i_fop = &proc_reg_file_ops_compat;

		}

#endif

	} else if (S_ISDIR(inode->i_mode)) {

		inode->i_op = de->proc_iops;

include/linux/proc_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ struct proc_ops { 
	unsigned int proc_flags;

	int	(*proc_open)(struct inode *, struct file *);

	ssize_t	(*proc_read)(struct file *, char __user *, size_t, loff_t *);

	ssize_t (*proc_read_iter)(struct kiocb *, struct iov_iter *);

	ssize_t	(*proc_write)(struct file *, const char __user *, size_t, loff_t *);

	loff_t	(*proc_lseek)(struct file *, loff_t, int);

	int	(*proc_release)(struct inode *, struct file *);