[RFC PATCH v11 34/51] ceph: get file size from fscrypt_file when present in inode traces

[Jeff Layton <jlayton@xxxxxxxxxx>]

When we get an inode trace from the MDS, grab the fscrypt_file field if
the inode is encrypted, and use it to populate the i_size field instead
of the regular inode size field.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
 fs/ceph/inode.c | 38 +++++++++++++++++++++++++-------------
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 599e27dae8c8..b905c49fc7a9 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -989,6 +989,16 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
 		     from_kgid(&init_user_ns, inode->i_gid));
 		ceph_decode_timespec64(&ci->i_btime, &iinfo->btime);
 		ceph_decode_timespec64(&ci->i_snap_btime, &iinfo->snap_btime);
+
+#ifdef CONFIG_FS_ENCRYPTION
+		if (iinfo->fscrypt_auth_len && !ci->fscrypt_auth) {
+			ci->fscrypt_auth_len = iinfo->fscrypt_auth_len;
+			ci->fscrypt_auth = iinfo->fscrypt_auth;
+			iinfo->fscrypt_auth = NULL;
+			iinfo->fscrypt_auth_len = 0;
+			inode_set_flags(inode, S_ENCRYPTED, S_ENCRYPTED);
+		}
+#endif
 	}
 
 	if ((new_version || (new_issued & CEPH_CAP_LINK_SHARED)) &&
@@ -1012,6 +1022,7 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
 
 	if (new_version ||
 	    (new_issued & (CEPH_CAP_ANY_FILE_RD | CEPH_CAP_ANY_FILE_WR))) {
+		u64 size = le64_to_cpu(info->size);
 		s64 old_pool = ci->i_layout.pool_id;
 		struct ceph_string *old_ns;
 
@@ -1025,10 +1036,21 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
 
 		pool_ns = old_ns;
 
+		if (IS_ENCRYPTED(inode) && size && (iinfo->fscrypt_file_len == sizeof(__le64))) {
+			u64 fsize = __le64_to_cpu(*(__le64 *)iinfo->fscrypt_file);
+
+			if (size == round_up(fsize, CEPH_FSCRYPT_BLOCK_SIZE)) {
+				size = fsize;
+			} else {
+				pr_warn("fscrypt size mismatch: size=%llu fscrypt_file=%llu, discarding fscrypt_file size.\n",
+					info->size, size);
+			}
+		}
+
 		queue_trunc = ceph_fill_file_size(inode, issued,
-					le32_to_cpu(info->truncate_seq),
-					le64_to_cpu(info->truncate_size),
-					le64_to_cpu(info->size));
+						  le32_to_cpu(info->truncate_seq),
+						  le64_to_cpu(info->truncate_size),
+						  size);
 		/* only update max_size on auth cap */
 		if ((info->cap.flags & CEPH_CAP_FLAG_AUTH) &&
 		    ci->i_max_size != le64_to_cpu(info->max_size)) {
@@ -1068,16 +1090,6 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
 		xattr_blob = NULL;
 	}
 
-#ifdef CONFIG_FS_ENCRYPTION
-	if (iinfo->fscrypt_auth_len && !ci->fscrypt_auth) {
-		ci->fscrypt_auth_len = iinfo->fscrypt_auth_len;
-		ci->fscrypt_auth = iinfo->fscrypt_auth;
-		iinfo->fscrypt_auth = NULL;
-		iinfo->fscrypt_auth_len = 0;
-		inode_set_flags(inode, S_ENCRYPTED, S_ENCRYPTED);
-	}
-#endif
-
 	/* finally update i_version */
 	if (le64_to_cpu(info->version) > ci->i_version)
 		ci->i_version = le64_to_cpu(info->version);
-- 
2.35.1