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>
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 43e54e8..bc0a0dd 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -597,6 +597,7 @@
ent->pde_users = 0;
spin_lock_init(&ent->pde_unload_lock);
ent->pde_unload_completion = NULL;
+ INIT_LIST_HEAD(&ent->pde_openers);
out:
return ent;
}
@@ -789,6 +790,19 @@
spin_unlock(&de->pde_unload_lock);
continue_removing:
+ spin_lock(&de->pde_unload_lock);
+ while (!list_empty(&de->pde_openers)) {
+ struct pde_opener *pdeo;
+
+ pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
+ list_del(&pdeo->lh);
+ spin_unlock(&de->pde_unload_lock);
+ pdeo->release(pdeo->inode, pdeo->file);
+ kfree(pdeo);
+ spin_lock(&de->pde_unload_lock);
+ }
+ spin_unlock(&de->pde_unload_lock);
+
if (S_ISDIR(de->mode))
parent->nlink--;
de->nlink = 0;