From d7065da038227a4d09a244e6014e0186a6bd21d0 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 26 May 2010 15:13:55 -0400 Subject: get rid of the magic around f_count in aio __aio_put_req() plays sick games with file refcount. What it wants is fput() from atomic context; it's almost always done with f_count > 1, so they only have to deal with delayed work in rare cases when their reference happens to be the last one. Current code decrements f_count and if it hasn't hit 0, everything is fine. Otherwise it keeps a pointer to struct file (with zero f_count!) around and has delayed work do __fput() on it. Better way to do it: use atomic_long_add_unless( , -1, 1) instead of !atomic_long_dec_and_test(). IOW, decrement it only if it's not the last reference, leave refcount alone if it was. And use normal fput() in delayed work. I've made that atomic_long_add_unless call a new helper - fput_atomic(). Drops a reference to file if it's safe to do in atomic (i.e. if that's not the last one), tells if it had been able to do that. aio.c converted to it, __fput() use is gone. req->ki_file *always* contributes to refcount now. And __fput() became static. Signed-off-by: Al Viro --- include/linux/file.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/file.h') diff --git a/include/linux/file.h b/include/linux/file.h index 5555508fd517..b1e12970f617 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -11,7 +11,6 @@ struct file; -extern void __fput(struct file *); extern void fput(struct file *); extern void drop_file_write_access(struct file *file); -- cgit