ceph: add some fscrypt guardrails

Add the appropriate calls into fscrypt for various actions, including
link, rename, setattr, and the open codepaths.

Disable fallocate for encrypted inodes -- hopefully, just for now.

If we have an encrypted inode, then the client will need to re-encrypt
the contents of the new object. Disable copy offload to or from
encrypted inodes.

Set i_blkbits to crypto block size for encrypted inodes -- some of the
underlying infrastructure for fscrypt relies on i_blkbits being aligned
to crypto blocksize.

Report STATX_ATTR_ENCRYPTED on encrypted inodes.

[ lhenriques: forbid encryption with striped layouts ]

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h
index 3269fc8f8cf38ed69b53cdcc1b79ac8e82e8f4bc..21694df7dfbf67aeb5fa57f0dfc8ad7c9a82ff98 100644 (file)
--- a/fs/ceph/crypto.h
+++ b/fs/ceph/crypto.h
@@ -9,6 +9,10 @@
 #include <crypto/sha2.h>
 #include <linux/fscrypt.h>
 
+#define CEPH_FSCRYPT_BLOCK_SHIFT   12
+#define CEPH_FSCRYPT_BLOCK_SIZE    (_AC(1, UL) << CEPH_FSCRYPT_BLOCK_SHIFT)
+#define CEPH_FSCRYPT_BLOCK_MASK           (~(CEPH_FSCRYPT_BLOCK_SIZE-1))
+
 struct ceph_fs_client;
 struct ceph_acl_sec_ctx;
 struct ceph_mds_request;

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 7e064c024d2ab3da13390f2da54e66fca561f930..99fdc777dccd54272094231c6c885563f91cbff1 100644 (file)
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1148,6 +1148,10 @@ static int ceph_link(struct dentry *old_dentry, struct inode *dir,
        if (ceph_snap(dir) != CEPH_NOSNAP)
                return -EROFS;
 
+       err = fscrypt_prepare_link(old_dentry, dir, dentry);
+       if (err)
+               return err;
+
        dout("link in dir %p %llx.%llx old_dentry %p:'%pd' dentry %p:'%pd'\n",
             dir, ceph_vinop(dir), old_dentry, old_dentry, dentry, dentry);
        req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
@@ -1395,6 +1399,11 @@ static int ceph_rename(struct mnt_idmap *idmap, struct inode *old_dir,
        if (err)
                return err;
 
+       err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
+                                    flags);
+       if (err)
+               return err;
+
        dout("rename dir %p dentry %p to dir %p dentry %p\n",
             old_dir, old_dentry, new_dir, new_dentry);
        req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 9383ec312a045dfe080536af23ca0a37fc549f44..6e9ae398ef2c88a4114cd17119fbeaf99c5b6c8c 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -366,8 +366,13 @@ int ceph_open(struct inode *inode, struct file *file)
 
        /* filter out O_CREAT|O_EXCL; vfs did that already.  yuck. */
        flags = file->f_flags & ~(O_CREAT|O_EXCL);
-       if (S_ISDIR(inode->i_mode))
+       if (S_ISDIR(inode->i_mode)) {
                flags = O_DIRECTORY;  /* mds likes to know */
+       } else if (S_ISREG(inode->i_mode)) {
+               err = fscrypt_file_open(inode, file);
+               if (err)
+                       return err;
+       }
 
        dout("open inode %p ino %llx.%llx file %p flags %d (%d)\n", inode,
             ceph_vinop(inode), file, flags, file->f_flags);
@@ -879,6 +884,13 @@ retry:
                dout("atomic_open finish_no_open on dn %p\n", dn);
                err = finish_no_open(file, dn);
        } else {
+               if (IS_ENCRYPTED(dir) &&
+                   !fscrypt_has_permitted_context(dir, d_inode(dentry))) {
+                       pr_warn("Inconsistent encryption context (parent %llx:%llx child %llx:%llx)\n",
+                               ceph_vinop(dir), ceph_vinop(d_inode(dentry)));
+                       goto out_req;
+               }
+
                dout("atomic_open finish_open on dn %p\n", dn);
                if (req->r_op == CEPH_MDS_OP_CREATE && req->r_reply_info.has_create_ino) {
                        struct inode *newino = d_inode(dentry);
@@ -2222,6 +2234,9 @@ static long ceph_fallocate(struct file *file, int mode,
        if (!S_ISREG(inode->i_mode))
                return -EOPNOTSUPP;
 
+       if (IS_ENCRYPTED(inode))
+               return -EOPNOTSUPP;
+
        prealloc_cf = ceph_alloc_cap_flush();
        if (!prealloc_cf)
                return -ENOMEM;
@@ -2543,6 +2558,10 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off,
                return -EOPNOTSUPP;
        }
 
+       /* Every encrypted inode gets its own key, so we can't offload them */
+       if (IS_ENCRYPTED(src_inode) || IS_ENCRYPTED(dst_inode))
+               return -EOPNOTSUPP;
+
        if (len < src_ci->i_layout.object_size)
                return -EOPNOTSUPP; /* no remote copy will be done */
 

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 5423c69ac434f5e918d3fdc09874af2a8c56f6ce..828badfe62a8a8a2ec660869f4548c38b8a3cd95 100644 (file)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -972,13 +972,6 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
        issued |= __ceph_caps_dirty(ci);
        new_issued = ~issued & info_caps;
 
-       /* directories have fl_stripe_unit set to zero */
-       if (le32_to_cpu(info->layout.fl_stripe_unit))
-               inode->i_blkbits =
-                       fls(le32_to_cpu(info->layout.fl_stripe_unit)) - 1;
-       else
-               inode->i_blkbits = CEPH_BLOCK_SHIFT;
-
        __ceph_update_quota(ci, iinfo->max_bytes, iinfo->max_files);
 
 #ifdef CONFIG_FS_ENCRYPTION
@@ -1004,6 +997,15 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
                ceph_decode_timespec64(&ci->i_snap_btime, &iinfo->snap_btime);
        }
 
+       /* directories have fl_stripe_unit set to zero */
+       if (IS_ENCRYPTED(inode))
+               inode->i_blkbits = CEPH_FSCRYPT_BLOCK_SHIFT;
+       else if (le32_to_cpu(info->layout.fl_stripe_unit))
+               inode->i_blkbits =
+                       fls(le32_to_cpu(info->layout.fl_stripe_unit)) - 1;
+       else
+               inode->i_blkbits = CEPH_BLOCK_SHIFT;
+
        if ((new_version || (new_issued & CEPH_CAP_LINK_SHARED)) &&
            (issued & CEPH_CAP_LINK_EXCL) == 0)
                set_nlink(inode, le32_to_cpu(info->nlink));
@@ -2495,6 +2497,10 @@ int ceph_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
        if (ceph_inode_is_shutdown(inode))
                return -ESTALE;
 
+       err = fscrypt_prepare_setattr(dentry, attr);
+       if (err)
+               return err;
+
        err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
        if (err != 0)
                return err;
@@ -2778,8 +2784,12 @@ int ceph_getattr(struct mnt_idmap *idmap, const struct path *path,
                        stat->nlink = 1 + 1 + ci->i_subdirs;
        }
 
-       stat->attributes_mask |= STATX_ATTR_CHANGE_MONOTONIC;
        stat->attributes |= STATX_ATTR_CHANGE_MONOTONIC;
+       if (IS_ENCRYPTED(inode))
+               stat->attributes |= STATX_ATTR_ENCRYPTED;
+       stat->attributes_mask |= (STATX_ATTR_CHANGE_MONOTONIC |
+                                 STATX_ATTR_ENCRYPTED);
+
        stat->result_mask = request_mask & valid_mask;
        return err;
 }

diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index 11d37d3073829407283dd21e5ce8d4d75034e818..91a84917d203c54527ba676a32c23bb1a00cf1da 100644 (file)
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -294,6 +294,10 @@ static long ceph_set_encryption_policy(struct file *file, unsigned long arg)
        struct inode *inode = file_inode(file);
        struct ceph_inode_info *ci = ceph_inode(inode);
 
+       /* encrypted directories can't have striped layout */
+       if (ci->i_layout.stripe_count > 1)
+               return -EINVAL;
+
        ret = vet_mds_for_fscrypt(file);
        if (ret)
                return ret;