Re: Commit "new primitive: discard_new_inode()" introduces a problem

[Al Viro]

On Wed, Aug 01, 2018 at 07:19:35PM +0300, Kirill Tkhai wrote:
> On 01.08.2018 19:16, Al Viro wrote:
> > On Wed, Aug 01, 2018 at 05:11:51PM +0100, Al Viro wrote:
> >> On Wed, Aug 01, 2018 at 06:43:56PM +0300, Kirill Tkhai wrote:
> >>> #git status
> >>> HEAD detached at 22dc9a168272
> >>
> >> Wait a sec - just that commit?  With discard_new_inode() not even
> >> used anywhere?  Then any of those -ENOMEM is disguised ERR_PTR(-ESTALE)
> >> from find_inode()/find_inode_fast(), i.e. an inode found by
> >> iget5_locked() (your /etc is on ext4) with I_CREATING still set.
> > 
> > iget_locked(), that is.

OK, I see what's going on there.  See if this fixes the problem:

diff --git a/fs/dcache.c b/fs/dcache.c
index 0e8e5de3c48a..b11f566bcd66 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1892,7 +1892,7 @@ void d_instantiate_new(struct dentry *entry, struct inode 
*inode)
        spin_lock(&inode->i_lock);
        __d_instantiate(entry, inode);
        WARN_ON(!(inode->i_state & I_NEW));
-       inode->i_state &= ~I_NEW;
+       inode->i_state &= ~I_NEW & ~I_CREATING;
        smp_mb();
        wake_up_bit(&inode->i_state, __I_NEW);
        spin_unlock(&inode->i_lock);