On Thu, 2020-05-14 at 12:14 +0100, Luis Henriques wrote:
> Similarly to commit 03f219041fdb ("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")
> - open_by_handle_at()
>
> The call to open_by_handle_at should not fail because the file still
> exists and we do have a valid handle to it.
>
> Signed-off-by: Luis Henriques <lhenriques@xxxxxxxx>
> ---
> fs/ceph/export.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ceph/export.c b/fs/ceph/export.c
> index 79dc06881e78..8556df9d94d0 100644
> --- a/fs/ceph/export.c
> +++ b/fs/ceph/export.c
> @@ -171,12 +171,21 @@ struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
>
> static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
> {
> + struct ceph_inode_info *ci;
> struct inode *inode = __lookup_inode(sb, ino);
> +
> if (IS_ERR(inode))
> return ERR_CAST(inode);
> if (inode->i_nlink == 0) {
> - iput(inode);
> - return ERR_PTR(-ESTALE);
> + bool is_open;
> + ci = ceph_inode(inode);
> + spin_lock(&ci->i_ceph_lock);
> + is_open = __ceph_is_file_opened(ci);
> + spin_unlock(&ci->i_ceph_lock);
> + if (!is_open) {
> + iput(inode);
> + return ERR_PTR(-ESTALE);
> + }
> }
> return d_obtain_alias(inode);
> }
Thanks Luis. Out of curiousity, is there any reason we shouldn't ignore
the i_nlink value here? Does anything obviously break if we do?
Thanks,
--
Jeff Layton <jlayton@xxxxxxxxxx>
