Commit 47458802 authored by Al Viro's avatar Al Viro
Browse files

procfs: move dropping pde and pid from ->evict_inode() to ->free_inode() 



that keeps both around until struct inode is freed, making access
to them safe from rcu-pathwalk

Acked-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent c1b967d0

fs/proc/base.c

+0 −2
Original line number Diff line number Diff line
@@ -1878,8 +1878,6 @@ void proc_pid_evict_inode(struct proc_inode *ei) 
		hlist_del_init_rcu(&ei->sibling_inodes);

		spin_unlock(&pid->lock);

	}



	put_pid(pid);

}



struct inode *proc_pid_make_inode(struct super_block *sb,

fs/proc/inode.c

+8 −11
Original line number Diff line number Diff line
@@ -30,7 +30,6 @@ 


static void proc_evict_inode(struct inode *inode)

{

	struct proc_dir_entry *de;

	struct ctl_table_header *head;

	struct proc_inode *ei = PROC_I(inode);
@@ -38,17 +37,8 @@ static void proc_evict_inode(struct inode *inode) 
	clear_inode(inode);



	/* Stop tracking associated processes */

	if (ei->pid) {

	if (ei->pid)

		proc_pid_evict_inode(ei);

		ei->pid = NULL;

	}



	/* Let go of any associated proc directory entry */

	de = ei->pde;

	if (de) {

		pde_put(de);

		ei->pde = NULL;

	}



	head = ei->sysctl;

	if (head) {
@@ -80,6 +70,13 @@ static struct inode *proc_alloc_inode(struct super_block *sb) 


static void proc_free_inode(struct inode *inode)

{

	struct proc_inode *ei = PROC_I(inode);



	if (ei->pid)

		put_pid(ei->pid);

	/* Let go of any associated proc directory entry */

	if (ei->pde)

		pde_put(ei->pde);

	kmem_cache_free(proc_inode_cachep, PROC_I(inode));

}