Re: [PATCH] fscrypt: allow filesystems to disable symlink target caching

[Eric Biggers <ebiggers@kernel.org>]

On Thu, Oct 15, 2026 at 05:46:24PM +0000, Alex Markuze wrote:
> fscrypt stores decrypted symlink targets in inode->i_link. The VFS can
> use this field without calling the filesystem's ->get_link() callback.
> The target can remain valid after the access policy changes.
> 
> The CephFS subvolume quarantine series adds access checks to
> ->get_link(). Quarantine can revoke access after a target is cached. The
> VFS cache can bypass these checks.
> 
> The no_symlink_cache option in fscrypt_operations gives filesystems
> control of this cache. It applies during target creation, lookup and
> getattr. With this option set, the helpers do not read or update
> ->i_link. The filesystem callback can then revalidate access.
> 
> Uncached targets use the existing delayed-free callback. Each uncached
> lookup allocates a temporary buffer and decrypts or encodes the target.
> This lets Ceph reuse fscrypt's target validation and buffer ownership.
> 
> The default setting keeps the current cache behavior for other
> filesystems. Ceph selects the option so cached targets cannot bypass its
> ->get_link() checks.
> 
> Signed-off-by: Alex Markuze <amarkuze@redhat.com>

This sounds like a bug fix?  If so, which commit is it fixing?

- Eric