[...]
> > > So yeh, I do think it is manageable. I think the best solution would be
> > > something along the lines of wrappers like the following:
> > >
> > > static inline int vfs_mkdir(...)
> > > {
> > > int error = __vfs_mkdir_nonotify(...);
> > > if (!error)
> > > fsnotify_mkdir(dir, dentry);
> > > return error;
> > > }
> > >
> > > And then the few call sites that call the fsnotify_path_ hooks
> > > (i.e. in syscalls and perhaps later in nfsd) will call the
> > > __vfs_xxx_nonotify() variant.
> >
> > Yes, that is OK with me. Or we could have something like:
> >
> > static inline void fsnotify_dirent(struct vfsmount *mnt, struct inode *dir,
> > struct dentry *dentry, __u32 mask)
> > {
> > if (!mnt) {
> > fsnotify(mask, d_inode(dentry), FSNOTIFY_EVENT_INODE, dir,
> > &dentry->d_name, NULL, 0);
> > } else {
> > struct path path = {
> > .mnt = mnt,
> > .dentry = d_find_any_alias(dir)
> > };
> > fsnotify(mask, d_inode(dentry), FSNOTIFY_EVENT_PATH, &path,
> > &dentry->d_name, NULL, 0);
> > }
> > }
> >
> > static inline void fsnotify_mkdir(struct vfsmount *mnt, struct inode *inode,
> > struct dentry *dentry)
> > {
> > audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
> >
> > fsnotify_dirent(mnt, inode, dentry, FS_CREATE | FS_ISDIR);
> > }
> >
> > static inline int vfs_mkdir(mnt, ...)
> > {
> > int error = __vfs_mkdir_nonotify(...);
> > if (!error)
> > fsnotify_mkdir(mnt, dir, dentry);
> > }
> >
>
> I've done something similar to that. I think it's a bit cleaner,
> but we can debate on the details later.
> Pushed POC to branch fsnotify_path_hooks.
FYI, I tried your suggested approach above for fsnotify_xattr(),
but I think I prefer to use an explicit flavor fsnotify_xattr_mnt()
and a wrapper fsnotify_xattr().
Pushed WIP to fsnotify_path_hooks branch. It also contains
some unstashed "fix" patches to tidy up the previous hooks.
I ran into another hurdle with fsnotify_xattr() -
vfs_setxattr() is too large to duplicate a _nonotify() variant IMO.
OTOH, I cannot lift fsnotify_xattr() up to callers without moving
the fsnotify hook outside the inode lock.
This was not a problem with the directory entry path hooks.
This is also not going to be a problem with fsnotify_change(),
because notify_change() is called with inode locked.
Do you think that calling fsnotify_xattr() under inode lock is important?
Should I refactor a helper vfs_setxattr_notify() that takes a boolean
arg for optionally calling fsnotify_xattr()?
Do you have another idea how to deal with that hook?
With notify_change() I have a different silly problem with using the
refactoring method - the name notify_change_nonotify() is unacceptable.
We may consider __ATTR_NONOTIFY ia_valid flag as the method to
use instead of refactoring in this case, just because we can and
because it creates less clutter.
What do you think?
Thanks,
Amir.
