On Wed, 2021-09-29 at 08:05 +0200, Greg Kroah-Hartman wrote: > On Wed, Sep 29, 2021 at 11:04:34AM +0800, Ian Kent wrote: > > In kernfs_iop_lookup() a negative dentry is created if there's no > > kernfs > > node associated with the dentry or the node is inactive. > > > > But inactive kernfs nodes are meant to be invisible to the VFS and > > creating a negative dentry for these can have unexpected side > > effects > > when the node transitions to an active state. > > > > The point of creating negative dentries is to avoid the expensive > > alloc/free cycle that occurs if there are frequent lookups for > > kernfs > > attributes that don't exist. So kernfs nodes that are not yet > > active > > should not result in a negative dentry being created so when they > > transition to an active state VFS lookups can create an associated > > dentry is a natural way. > > > > Signed-off-by: Ian Kent <raven@xxxxxxxxxx> > > --- > > fs/kernfs/dir.c | 9 ++++++++- > > 1 file changed, 8 insertions(+), 1 deletion(-) > > Does this fix a specific commit and need a "Fixes:" tag? Oh, of course yes, apologies, my bad. I re-post it. Ian
