Re: [RFC PATCH v4 15/17] ceph: make d_revalidate call fscrypt revalidator for encrypted dentries

Luis Henriques
2021-02-01T17:18:23Z

Jeff Layton <jlayton@kernel.org> writes:

> If we have a dentry which represents a no-key name, then we need to test
> whether the parent directory's encryption key has since been added. Do
> that before we test anything else about the dentry.
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> fs/ceph/dir.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
> index 236c381ab6bd..cb7ff91a243a 100644
> --- a/fs/ceph/dir.c
> +++ b/fs/ceph/dir.c
> @@ -1726,6 +1726,10 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
> dout("d_revalidate %p '%pd' inode %p offset 0x%llx\n", dentry,
> dentry, inode, ceph_dentry(dentry)->offset);
>
> + valid = fscrypt_d_revalidate(dentry, flags);
> + if (valid <= 0)
> + return valid;
> +

This one took me a while to figure out, but eventually got there.
Initially I was seeing this error:

crypt: ceph: 1 inode(s) still busy after removing key with identifier f019f4a1c5d5665675218f89fccfa3c7, including ino 1099511627791

and, when umounting the filesystem I would get the warning in
fs/dcache.c:1623.

Anyway, the patch below should fix it.

Unfortunately I didn't had a lot of time to look into the -experimental
branch yet. On my TODO list for the next few days.

Cheers,
--
Luis

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index ae0890be0c9d..d3ac39c6645f 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1781,7 +1781,7 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)

valid = fscrypt_d_revalidate(dentry, flags);
if (valid <= 0)
- return valid;
+ goto out;

mdsc = ceph_sb_to_client(dir->i_sb)->mdsc;

@@ -1853,6 +1853,7 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
if (!valid)
ceph_dir_clear_complete(dir);

+out:
if (!(flags & LOOKUP_RCU))
dput(parent);
return valid;

> mdsc = ceph_sb_to_client(dir->i_sb)->mdsc;
>
> /* always trust cached snapped dentries, snapdir dentry */
> --
>
> 2.29.2
>