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, 1 insertions, 0 deletions

diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index cdabc2fc02f7..f560d1705afe 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -79,6 +79,7 @@ struct proc_dir_entry {
         int pde_users;  /* number of callers into module in progress */
         spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
         struct completion *pde_unload_completion;
+        struct list_head pde_openers;   /* who did ->open, but not ->release */
 };
 
 struct kcore_list {