[PATCH v13 41/59] ceph: get file size from fscrypt_file when present in inode traces

[Jeff Layton <jlayton@kernel.org>]

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@kernel.org>
---
 fs/ceph/inode.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index b9454721c976..f2a59306e4a6 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1024,6 +1024,7 @@ 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;
 
@@ -1037,10 +1038,21 @@ 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)) {
-- 
2.35.1