[ Upstream commit 878dabb64117406abd40977b87544d05bb3031fc ]
Similarly to commit 03f219041f ("ceph: check i_nlink while converting
a file handle to dentry"), this fixes another corner case with
name_to_handle_at/open_by_handle_at. The issue has been detected by
xfstest generic/467, when doing:
- name_to_handle_at("/cephfs/myfile")
- open("/cephfs/myfile")
- unlink("/cephfs/myfile")
- sync; sync;
- drop caches
- open_by_handle_at()
The call to open_by_handle_at should not fail because the file hasn't been
deleted yet (only unlinked) and we do have a valid handle to it. -ESTALE
shall be returned only if i_nlink is 0 *and* i_count is 1.
This patch also makes sure we have LINK caps before checking i_nlink.
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
8074607871