| Message ID | 20210120182847.644850-9-jlayton@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | ceph+fscrypt: context, filename and symlink support | expand |
Jeff Layton <jlayton@kernel.org> writes: > After pre-creating a new inode, do an fscrypt prepare on it, fetch a > new encryption context and then marshal that into the security context > to be sent along with the RPC. > > Signed-off-by: Jeff Layton <jlayton@kernel.org> > --- > fs/ceph/crypto.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++ > fs/ceph/crypto.h | 12 ++++++++++ > fs/ceph/inode.c | 9 +++++-- > fs/ceph/super.h | 3 +++ > 4 files changed, 83 insertions(+), 2 deletions(-) > > diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c > index 879d9a0d3751..f037a4939026 100644 > --- a/fs/ceph/crypto.c > +++ b/fs/ceph/crypto.c > @@ -46,3 +46,64 @@ void ceph_fscrypt_set_ops(struct super_block *sb) > { > fscrypt_set_ops(sb, &ceph_fscrypt_ops); > } > + > +int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, > + struct ceph_acl_sec_ctx *as) > +{ > + int ret, ctxsize; > + size_t name_len; > + char *name; > + struct ceph_pagelist *pagelist = as->pagelist; > + bool encrypted = false; > + > + ret = fscrypt_prepare_new_inode(dir, inode, &encrypted); > + if (ret) > + return ret; > + if (!encrypted) > + return 0; > + > + inode->i_flags |= S_ENCRYPTED; > + > + ctxsize = fscrypt_context_for_new_inode(&as->fscrypt, inode); > + if (ctxsize < 0) > + return ctxsize; > + > + /* marshal it in page array */ > + if (!pagelist) { > + pagelist = ceph_pagelist_alloc(GFP_KERNEL); > + if (!pagelist) > + return -ENOMEM; > + ret = ceph_pagelist_reserve(pagelist, PAGE_SIZE); > + if (ret) > + goto out; > + ceph_pagelist_encode_32(pagelist, 1); > + } > + > + name = CEPH_XATTR_NAME_ENCRYPTION_CONTEXT; > + name_len = strlen(name); > + ret = ceph_pagelist_reserve(pagelist, 4 * 2 + name_len + ctxsize); > + if (ret) > + goto out; > + > + if (as->pagelist) { > + BUG_ON(pagelist->length <= sizeof(__le32)); > + if (list_is_singular(&pagelist->head)) { > + le32_add_cpu((__le32*)pagelist->mapped_tail, 1); > + } else { > + struct page *page = list_first_entry(&pagelist->head, > + struct page, lru); > + void *addr = kmap_atomic(page); > + le32_add_cpu((__le32*)addr, 1); > + kunmap_atomic(addr); > + } > + } > + I've been staring at this function for a bit. And at this point I would expect something like this: } else as->pagelist = pagelist; as I'm not seeing pagelist being used anywhere if it's allocated in this function. Cheers,
On Fri, 2021-01-22 at 16:50 +0000, Luis Henriques wrote: > Jeff Layton <jlayton@kernel.org> writes: > > > After pre-creating a new inode, do an fscrypt prepare on it, fetch a > > new encryption context and then marshal that into the security context > > to be sent along with the RPC. > > > > Signed-off-by: Jeff Layton <jlayton@kernel.org> > > --- > > fs/ceph/crypto.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++ > > fs/ceph/crypto.h | 12 ++++++++++ > > fs/ceph/inode.c | 9 +++++-- > > fs/ceph/super.h | 3 +++ > > 4 files changed, 83 insertions(+), 2 deletions(-) > > > > diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c > > index 879d9a0d3751..f037a4939026 100644 > > --- a/fs/ceph/crypto.c > > +++ b/fs/ceph/crypto.c > > @@ -46,3 +46,64 @@ void ceph_fscrypt_set_ops(struct super_block *sb) > > { > > fscrypt_set_ops(sb, &ceph_fscrypt_ops); > > } > > + > > +int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, > > + struct ceph_acl_sec_ctx *as) > > +{ > > + int ret, ctxsize; > > + size_t name_len; > > + char *name; > > + struct ceph_pagelist *pagelist = as->pagelist; > > + bool encrypted = false; > > + > > + ret = fscrypt_prepare_new_inode(dir, inode, &encrypted); > > + if (ret) > > + return ret; > > + if (!encrypted) > > + return 0; > > + > > + inode->i_flags |= S_ENCRYPTED; > > + > > + ctxsize = fscrypt_context_for_new_inode(&as->fscrypt, inode); > > + if (ctxsize < 0) > > + return ctxsize; > > + > > + /* marshal it in page array */ > > + if (!pagelist) { > > + pagelist = ceph_pagelist_alloc(GFP_KERNEL); > > + if (!pagelist) > > + return -ENOMEM; > > + ret = ceph_pagelist_reserve(pagelist, PAGE_SIZE); > > + if (ret) > > + goto out; > > + ceph_pagelist_encode_32(pagelist, 1); > > + } > > + > > + name = CEPH_XATTR_NAME_ENCRYPTION_CONTEXT; > > + name_len = strlen(name); > > + ret = ceph_pagelist_reserve(pagelist, 4 * 2 + name_len + ctxsize); > > + if (ret) > > + goto out; > > + > > + if (as->pagelist) { > > + BUG_ON(pagelist->length <= sizeof(__le32)); > > + if (list_is_singular(&pagelist->head)) { > > + le32_add_cpu((__le32*)pagelist->mapped_tail, 1); > > + } else { > > + struct page *page = list_first_entry(&pagelist->head, > > + struct page, lru); > > + void *addr = kmap_atomic(page); > > + le32_add_cpu((__le32*)addr, 1); > > + kunmap_atomic(addr); > > + } > > + } > > + > > I've been staring at this function for a bit. And at this point I would > expect something like this: > > } else > as->pagelist = pagelist; > > as I'm not seeing pagelist being used anywhere if it's allocated in this > function. > It gets used near the end, in the ceph_pagelist_append calls. Once we've appended the xattr, we don't need the pagelist anymore and can free it. That said, the whole way the ceph_pagelist stuff is managed is weird. I'm not clear why it was done that way, and maybe we ought to rework this, SELinux and ACL handling to not use them. I think that's a cleanup for another day.
Jeff Layton <jlayton@kernel.org> writes: > On Fri, 2021-01-22 at 16:50 +0000, Luis Henriques wrote: >> Jeff Layton <jlayton@kernel.org> writes: >> >> > After pre-creating a new inode, do an fscrypt prepare on it, fetch a >> > new encryption context and then marshal that into the security context >> > to be sent along with the RPC. >> > >> > Signed-off-by: Jeff Layton <jlayton@kernel.org> >> > --- >> > fs/ceph/crypto.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++ >> > fs/ceph/crypto.h | 12 ++++++++++ >> > fs/ceph/inode.c | 9 +++++-- >> > fs/ceph/super.h | 3 +++ >> > 4 files changed, 83 insertions(+), 2 deletions(-) >> > >> > diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c >> > index 879d9a0d3751..f037a4939026 100644 >> > --- a/fs/ceph/crypto.c >> > +++ b/fs/ceph/crypto.c >> > @@ -46,3 +46,64 @@ void ceph_fscrypt_set_ops(struct super_block *sb) >> > { >> > fscrypt_set_ops(sb, &ceph_fscrypt_ops); >> > } >> > + >> > +int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, >> > + struct ceph_acl_sec_ctx *as) >> > +{ >> > + int ret, ctxsize; >> > + size_t name_len; >> > + char *name; >> > + struct ceph_pagelist *pagelist = as->pagelist; >> > + bool encrypted = false; >> > + >> > + ret = fscrypt_prepare_new_inode(dir, inode, &encrypted); >> > + if (ret) >> > + return ret; >> > + if (!encrypted) >> > + return 0; >> > + >> > + inode->i_flags |= S_ENCRYPTED; >> > + >> > + ctxsize = fscrypt_context_for_new_inode(&as->fscrypt, inode); >> > + if (ctxsize < 0) >> > + return ctxsize; >> > + >> > + /* marshal it in page array */ >> > + if (!pagelist) { >> > + pagelist = ceph_pagelist_alloc(GFP_KERNEL); >> > + if (!pagelist) >> > + return -ENOMEM; >> > + ret = ceph_pagelist_reserve(pagelist, PAGE_SIZE); >> > + if (ret) >> > + goto out; >> > + ceph_pagelist_encode_32(pagelist, 1); >> > + } >> > + >> > + name = CEPH_XATTR_NAME_ENCRYPTION_CONTEXT; >> > + name_len = strlen(name); >> > + ret = ceph_pagelist_reserve(pagelist, 4 * 2 + name_len + ctxsize); >> > + if (ret) >> > + goto out; >> > + >> > + if (as->pagelist) { >> > + BUG_ON(pagelist->length <= sizeof(__le32)); >> > + if (list_is_singular(&pagelist->head)) { >> > + le32_add_cpu((__le32*)pagelist->mapped_tail, 1); >> > + } else { >> > + struct page *page = list_first_entry(&pagelist->head, >> > + struct page, lru); >> > + void *addr = kmap_atomic(page); >> > + le32_add_cpu((__le32*)addr, 1); >> > + kunmap_atomic(addr); >> > + } >> > + } >> > + >> >> I've been staring at this function for a bit. And at this point I would >> expect something like this: >> >> } else >> as->pagelist = pagelist; >> >> as I'm not seeing pagelist being used anywhere if it's allocated in this >> function. >> > > It gets used near the end, in the ceph_pagelist_append calls. Once we've > appended the xattr, we don't need the pagelist anymore and can free it. Doh! Sorry for the noise ;-) Cheers,
diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index 879d9a0d3751..f037a4939026 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -46,3 +46,64 @@ void ceph_fscrypt_set_ops(struct super_block *sb) { fscrypt_set_ops(sb, &ceph_fscrypt_ops); } + +int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, + struct ceph_acl_sec_ctx *as) +{ + int ret, ctxsize; + size_t name_len; + char *name; + struct ceph_pagelist *pagelist = as->pagelist; + bool encrypted = false; + + ret = fscrypt_prepare_new_inode(dir, inode, &encrypted); + if (ret) + return ret; + if (!encrypted) + return 0; + + inode->i_flags |= S_ENCRYPTED; + + ctxsize = fscrypt_context_for_new_inode(&as->fscrypt, inode); + if (ctxsize < 0) + return ctxsize; + + /* marshal it in page array */ + if (!pagelist) { + pagelist = ceph_pagelist_alloc(GFP_KERNEL); + if (!pagelist) + return -ENOMEM; + ret = ceph_pagelist_reserve(pagelist, PAGE_SIZE); + if (ret) + goto out; + ceph_pagelist_encode_32(pagelist, 1); + } + + name = CEPH_XATTR_NAME_ENCRYPTION_CONTEXT; + name_len = strlen(name); + ret = ceph_pagelist_reserve(pagelist, 4 * 2 + name_len + ctxsize); + if (ret) + goto out; + + if (as->pagelist) { + BUG_ON(pagelist->length <= sizeof(__le32)); + if (list_is_singular(&pagelist->head)) { + le32_add_cpu((__le32*)pagelist->mapped_tail, 1); + } else { + struct page *page = list_first_entry(&pagelist->head, + struct page, lru); + void *addr = kmap_atomic(page); + le32_add_cpu((__le32*)addr, 1); + kunmap_atomic(addr); + } + } + + ceph_pagelist_encode_32(pagelist, name_len); + ceph_pagelist_append(pagelist, name, name_len); + ceph_pagelist_encode_32(pagelist, ctxsize); + ceph_pagelist_append(pagelist, as->fscrypt, ctxsize); +out: + if (pagelist && !as->pagelist) + ceph_pagelist_release(pagelist); + return ret; +} diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h index 0dd043b56096..cc4e481bf13a 100644 --- a/fs/ceph/crypto.h +++ b/fs/ceph/crypto.h @@ -18,6 +18,9 @@ static inline void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc) fscrypt_free_dummy_policy(&fsc->dummy_enc_policy); } +int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, + struct ceph_acl_sec_ctx *as); + #else /* CONFIG_FS_ENCRYPTION */ static inline void ceph_fscrypt_set_ops(struct super_block *sb) @@ -27,6 +30,15 @@ static inline void ceph_fscrypt_set_ops(struct super_block *sb) static inline void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc) { } + +static inline int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, + struct ceph_acl_sec_ctx *as) +{ + if (IS_ENCRYPTED(dir)) + return -EOPNOTSUPP; + return 0; +} + #endif /* CONFIG_FS_ENCRYPTION */ #endif diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index d004f294a256..2854711e8988 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -83,12 +83,17 @@ struct inode *ceph_new_inode(struct inode *dir, struct dentry *dentry, goto out_err; } + inode->i_state = 0; + inode->i_mode = *mode; + err = ceph_security_init_secctx(dentry, *mode, as_ctx); if (err < 0) goto out_err; - inode->i_state = 0; - inode->i_mode = *mode; + err = ceph_fscrypt_prepare_context(dir, inode, as_ctx); + if (err) + goto out_err; + return inode; out_err: iput(inode); diff --git a/fs/ceph/super.h b/fs/ceph/super.h index 7a022c7c38b6..2411813ab552 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -1031,6 +1031,9 @@ struct ceph_acl_sec_ctx { #ifdef CONFIG_CEPH_FS_SECURITY_LABEL void *sec_ctx; u32 sec_ctxlen; +#endif +#ifdef CONFIG_FS_ENCRYPTION + u8 fscrypt[FSCRYPT_SET_CONTEXT_MAX_SIZE]; #endif struct ceph_pagelist *pagelist; };
After pre-creating a new inode, do an fscrypt prepare on it, fetch a new encryption context and then marshal that into the security context to be sent along with the RPC. Signed-off-by: Jeff Layton <jlayton@kernel.org> --- fs/ceph/crypto.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/ceph/crypto.h | 12 ++++++++++ fs/ceph/inode.c | 9 +++++-- fs/ceph/super.h | 3 +++ 4 files changed, 83 insertions(+), 2 deletions(-)