Commit 6dfbbae1 authored by Muchun Song's avatar Muchun Song Committed by Linus Torvalds
Browse files

fs: proc: store PDE()->data into inode->i_private 

PDE_DATA(inode) is introduced to get user private data and hide the
layout of struct proc_dir_entry.  The inode->i_private is used to do the
same thing as well.  Save a copy of user private data to inode->
i_private when proc inode is allocated.  This means the user also can
get their private data by inode->i_private.

Introduce pde_data() to wrap inode->i_private so that we can remove
PDE_DATA() from fs/proc/generic.c and make PTE_DATE() as a wrapper of
pde_data().  It will be easier if we decide to remove PDE_DATE() in the
future.

Link: https://lkml.kernel.org/r/20211124081956.87711-1-songmuchun@bytedance.com


Signed-off-by: default avatarMuchun Song <songmuchun@bytedance.com>
Acked-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexey Gladkov <gladkov.alexey@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a3726599

fs/proc/generic.c

+0 −6
Original line number Diff line number Diff line
@@ -791,12 +791,6 @@ void proc_remove(struct proc_dir_entry *de) 
}

EXPORT_SYMBOL(proc_remove);



void *PDE_DATA(const struct inode *inode)

{

	return __PDE_DATA(inode);

}

EXPORT_SYMBOL(PDE_DATA);



/*

 * Pull a user buffer into memory and pass it to the file's write handler if

 * one is supplied.  The ->write() method is permitted to modify the

fs/proc/inode.c

+1 −0
Original line number Diff line number Diff line
@@ -650,6 +650,7 @@ struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) 
		return NULL;

	}



	inode->i_private = de->data;

	inode->i_ino = de->low_ino;

	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);

	PROC_I(inode)->pde = de;

fs/proc/internal.h

+0 −5
Original line number Diff line number Diff line
@@ -115,11 +115,6 @@ static inline struct proc_dir_entry *PDE(const struct inode *inode) 
	return PROC_I(inode)->pde;

}



static inline void *__PDE_DATA(const struct inode *inode)

{

	return PDE(inode)->data;

}



static inline struct pid *proc_pid(const struct inode *inode)

{

	return PROC_I(inode)->pid;

include/linux/proc_fs.h

+12 −1
Original line number Diff line number Diff line
@@ -110,7 +110,18 @@ extern struct proc_dir_entry *proc_create_data(const char *, umode_t, 
struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops);

extern void proc_set_size(struct proc_dir_entry *, loff_t);

extern void proc_set_user(struct proc_dir_entry *, kuid_t, kgid_t);

extern void *PDE_DATA(const struct inode *);



/*

 * Obtain the private data passed by user through proc_create_data() or

 * related.

 */

static inline void *pde_data(const struct inode *inode)

{

	return inode->i_private;

}



#define PDE_DATA(i)	pde_data(i)



extern void *proc_get_parent_data(const struct inode *);

extern void proc_remove(struct proc_dir_entry *);

extern void remove_proc_entry(const char *, struct proc_dir_entry *);