proc: always do ->release

Current two-stage scheme of removing PDE emphasizes one bug in proc:

		open
				rmmod
				remove_proc_entry
		close

->release won't be called because ->proc_fops were cleared.  In simple
cases it's small memory leak.

For every ->open, ->release has to be done.  List of openers is introduced
which is traversed at remove_proc_entry() if neeeded.

Discussions with Al long ago (sigh).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 8d67616..4422023 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -89,3 +89,10 @@ struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *ino,
 		struct dentry *dentry);
 int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
 		filldir_t filldir);
+
+struct pde_opener {
+	struct inode *inode;
+	struct file *file;
+	int (*release)(struct inode *, struct file *);
+	struct list_head lh;
+};