Re: [PATCH resend] proc: Fix proc_kill_inodes to kill dentries on all proc superblocks

[sukadev@us.ibm.com]

Pavel Emelianov [xemul@openvz.org] wrote:
| Eric W. Biederman wrote:
| > It appears we overlooked support for removing generic proc files
| > when we added support for multiple proc super blocks.  Handle
| > that now.
| > 
| > Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| 
| AFAIS this is just making the kill for all the super blocks
| we have.
| 
| Acked-by: Pavel Emelyanov <xemul@openvz.org>

Acked-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>

| 
| > ---
| >  fs/proc/generic.c  |   38 +++++++++++++++++++++-----------------
| >  fs/proc/internal.h |    2 ++
| >  fs/proc/root.c     |    2 +-
| >  3 files changed, 24 insertions(+), 18 deletions(-)
| > 
| > diff --git a/fs/proc/generic.c b/fs/proc/generic.c
| > index 1bdb624..3906770 100644
| > --- a/fs/proc/generic.c
| > +++ b/fs/proc/generic.c
| > @@ -561,28 +561,32 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
| >  static void proc_kill_inodes(struct proc_dir_entry *de)
| >  {
| >  	struct list_head *p;
| > -	struct super_block *sb = proc_mnt->mnt_sb;
| > +	struct super_block *sb;
| >  
| >  	/*
| >  	 * Actually it's a partial revoke().
| >  	 */
| > -	file_list_lock();
| > -	list_for_each(p, &sb->s_files) {
| > -		struct file * filp = list_entry(p, struct file, f_u.fu_list);
| > -		struct dentry * dentry = filp->f_path.dentry;
| > -		struct inode * inode;
| > -		const struct file_operations *fops;
| > -
| > -		if (dentry->d_op != &proc_dentry_operations)
| > -			continue;
| > -		inode = dentry->d_inode;
| > -		if (PDE(inode) != de)
| > -			continue;
| > -		fops = filp->f_op;
| > -		filp->f_op = NULL;
| > -		fops_put(fops);
| > +	spin_lock(&sb_lock);
| > +	list_for_each_entry(sb, &proc_fs_type.fs_supers, s_instances) {
| > +		file_list_lock();
| > +		list_for_each(p, &sb->s_files) {
| > +			struct file * filp = list_entry(p, struct file, f_u.fu_list);
| > +			struct dentry * dentry = filp->f_path.dentry;
| > +			struct inode * inode;
| > +			const struct file_operations *fops;
| > +
| > +			if (dentry->d_op != &proc_dentry_operations)
| > +				continue;
| > +			inode = dentry->d_inode;
| > +			if (PDE(inode) != de)
| > +				continue;
| > +			fops = filp->f_op;
| > +			filp->f_op = NULL;
| > +			fops_put(fops);
| > +		}
| > +		file_list_unlock();
| >  	}
| > -	file_list_unlock();
| > +	spin_unlock(&sb_lock);
| >  }
| >  
| >  static struct proc_dir_entry *proc_create(struct proc_dir_entry **parent,
| > diff --git a/fs/proc/internal.h b/fs/proc/internal.h
| > index 1820eb2..1b2b6c6 100644
| > --- a/fs/proc/internal.h
| > +++ b/fs/proc/internal.h
| > @@ -78,3 +78,5 @@ static inline int proc_fd(struct inode *inode)
| >  {
| >  	return PROC_I(inode)->fd;
| >  }
| > +
| > +extern struct file_system_type proc_fs_type;
| > diff --git a/fs/proc/root.c b/fs/proc/root.c
| > index ec9cb3b..1f86bb8 100644
| > --- a/fs/proc/root.c
| > +++ b/fs/proc/root.c
| > @@ -98,7 +98,7 @@ static void proc_kill_sb(struct super_block *sb)
| >  	put_pid_ns(ns);
| >  }
| >  
| > -static struct file_system_type proc_fs_type = {
| > +struct file_system_type proc_fs_type = {
| >  	.name		= "proc",
| >  	.get_sb		= proc_get_sb,
| >  	.kill_sb	= proc_kill_sb,