Re: [PATCH v3] ceph: mark directory as non-complete complete after loading key

Xiubo Li
2022-11-29T08:48:19Z

Hi Luis,

BTW, which branch are you using to generate this patch ?

Could you rebase to the testing branch ?

Thanks

- Xiubo

On 22/11/2022 22:59, Luís Henriques wrote:
> When setting a directory's crypt context, ceph_dir_clear_complete() needs to
> be called otherwise if it was complete before, any existing (old) dentry will
> still be valid.
>
> This patch adds a wrapper around __fscrypt_prepare_readdir() which will
> ensure a directory is marked as non-complete if key status changes.
>
> Signed-off-by: Luís Henriques <lhenriques@suse.de>
> ---
> Hi!
>
> Hopefully I'm not breaking anything else. I've run a bunch of fstests and
> didn't saw any (new) failures.
>
> Changes since v2:
> - Created helper wrapper for __fscrypt_prepare_readdir()
> - Added calls to the new helper
>
> Changes since v1:
> - Moved the __ceph_dir_clear_complete() call from ceph_crypt_get_context()
> to ceph_lookup().
> - Added an __fscrypt_prepare_readdir() wrapper to check key status changes
>
> fs/ceph/crypto.c | 35 +++++++++++++++++++++++++++++++++--
> fs/ceph/crypto.h | 6 ++++++
> fs/ceph/dir.c | 8 ++++----
> fs/ceph/mds_client.c | 6 +++---
> 4 files changed, 46 insertions(+), 9 deletions(-)
>
> diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c
> index 35a2ccfe6899..5ef65a06af98 100644
> --- a/fs/ceph/crypto.c
> +++ b/fs/ceph/crypto.c
> @@ -397,8 +397,8 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname,
> goto out_inode;
> }
>
> - ret = __fscrypt_prepare_readdir(dir);
> - if (ret)
> + ret = ceph_fscrypt_prepare_readdir(dir);
> + if (ret < 0)
> goto out_inode;
>
> /*
> @@ -636,3 +636,34 @@ int ceph_fscrypt_encrypt_pages(struct inode *inode, struct page **page, u64 off,
> }
> return ret;
> }
> +
> +/**
> + * ceph_fscrypt_prepare_readdir - simple __fscrypt_prepare_readdir() wrapper
> + * @dir: directory inode for readdir prep
> + *
> + * Simple wrapper around __fscrypt_prepare_readdir() that will mark directory as
> + * non-complete if this call results in having the directory unlocked.
> + *
> + * Returns:
> + * 1 - if directory was locked and key is now loaded (i.e. dir is unlocked)
> + * 0 - if directory is still locked
> + * < 0 - if __fscrypt_prepare_readdir() fails
> + */
> +int ceph_fscrypt_prepare_readdir(struct inode *dir)
> +{
> + bool had_key = fscrypt_has_encryption_key(dir);
> + int err;
> +
> + if (!IS_ENCRYPTED(dir))
> + return 0;
> +
> + err = __fscrypt_prepare_readdir(dir);
> + if (err)
> + return err;
> + if (!had_key && fscrypt_has_encryption_key(dir)) {
> + /* directory just got unlocked, mark it as not complete */
> + ceph_dir_clear_complete(dir);
> + return 1;
> + }
> + return 0;
> +}
> diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h
> index c6ee993f4ec8..cad53ec916fd 100644
> --- a/fs/ceph/crypto.h
> +++ b/fs/ceph/crypto.h
> @@ -154,6 +154,7 @@ int ceph_fscrypt_decrypt_extents(struct inode *inode, struct page **page, u64 of
> struct ceph_sparse_extent *map, u32 ext_cnt);
> int ceph_fscrypt_encrypt_pages(struct inode *inode, struct page **page, u64 off,
> int len, gfp_t gfp);
> +int ceph_fscrypt_prepare_readdir(struct inode *dir);
>
> static inline struct page *ceph_fscrypt_pagecache_page(struct page *page)
> {
> @@ -254,6 +255,11 @@ static inline struct page *ceph_fscrypt_pagecache_page(struct page *page)
> {
> return page;
> }
> +
> +static inline int ceph_fscrypt_prepare_readdir(struct inode *dir)
> +{
> + return 0;
> +}
> #endif /* CONFIG_FS_ENCRYPTION */
>
> static inline loff_t ceph_fscrypt_page_offset(struct page *page)
> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
> index edc2bf0aab83..5829f27d058d 100644
> --- a/fs/ceph/dir.c
> +++ b/fs/ceph/dir.c
> @@ -343,8 +343,8 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
> ctx->pos = 2;
> }
>
> - err = fscrypt_prepare_readdir(inode);
> - if (err)
> + err = ceph_fscrypt_prepare_readdir(inode);
> + if (err < 0)
> return err;
>
> spin_lock(&ci->i_ceph_lock);
> @@ -784,8 +784,8 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
> return ERR_PTR(-ENAMETOOLONG);
>
> if (IS_ENCRYPTED(dir)) {
> - err = __fscrypt_prepare_readdir(dir);
> - if (err)
> + err = ceph_fscrypt_prepare_readdir(dir);
> + if (err < 0)
> return ERR_PTR(err);
> if (!fscrypt_has_encryption_key(dir)) {
> spin_lock(&dentry->d_lock);
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 9518ac8e407d..4becc9eada4b 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -2551,8 +2551,8 @@ static u8 *get_fscrypt_altname(const struct ceph_mds_request *req, u32 *plen)
> if (!IS_ENCRYPTED(dir))
> goto success;
>
> - ret = __fscrypt_prepare_readdir(dir);
> - if (ret)
> + ret = ceph_fscrypt_prepare_readdir(dir);
> + if (ret < 0)
> return ERR_PTR(ret);
>
> /* No key? Just ignore it. */
> @@ -2668,7 +2668,7 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, int for
> spin_unlock(&cur->d_lock);
> parent = dget_parent(cur);
>
> - ret = __fscrypt_prepare_readdir(d_inode(parent));
> + ret = ceph_fscrypt_prepare_readdir(d_inode(parent));
> if (ret < 0) {
> dput(parent);
> dput(cur);
>