Re: [PATCH] VFS: generate FS_CREATE before FS_OPEN when ->atomic_open used.

From: Al Viro
Date: Tue Jun 11 2024 - 22:38:08 EST


On Wed, Jun 12, 2024 at 12:05:11PM +1000, NeilBrown wrote:

> For finish_open() there are three cases:
> - finish_open is used in ->atomic_open handlers. For these we add a
> call to fsnotify_open() in do_open() if FMODE_OPENED is set - which
> means do_dentry_open() has been called. This happens after fsnotify_create().

Hummm.... There's a bit of behaviour change; in case we fail in
may_open(), we used to get fsnotify_open()+fsnotify_close() and with that
patch we's get fsnotify_close() alone.

IF we don't care about that, we might as well take fsnotify_open()
out of vfs_open() and, for do_open()/do_tmpfile()/do_o_path(), into
path_openat() itself. I mean, having
if (likely(!error)) {
if (likely(file->f_mode & FMODE_OPENED)) {
fsnotify_open(file);
return file;
}
in there would be a lot easier to follow... It would lose fsnotify_open()
in a few more failure exits, but if we don't give a damn about having it
paired with fsnotify_close()...