cifs: Fix missing set of remote_i_size

Occasionally, the generic/001 xfstest will fail indicating corruption in
one of the copy chains when run on cifs against a server that supports
FSCTL_DUPLICATE_EXTENTS_TO_FILE (eg. Samba with a share on btrfs).  The
problem is that the remote_i_size value isn't updated by cifs_setsize()
when called by smb2_duplicate_extents(), but i_size *is*.

This may cause cifs_remap_file_range() to then skip the bit after calling
->duplicate_extents() that sets sizes.

Fix this by calling netfs_resize_file() in smb2_duplicate_extents() before
calling cifs_setsize() to set i_size.

This means we don't then need to call netfs_resize_file() upon return from
->duplicate_extents(), but we also fix the test to compare against the pre-dup
inode size.

[Note that this goes back before the addition of remote_i_size with the
netfs_inode struct.  It should probably have been setting cifsi->server_eof
previously.]

Fixes: cfc63fc8126a ("smb3: fix cached file size problems in duplicate extents (reflink)")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index b87b70edd0be..4ce6c3121a7e 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -2028,6 +2028,7 @@ smb2_duplicate_extents(const unsigned int xid,
 		 * size will be queried on next revalidate, but it is important
 		 * to make sure that file's cached size is updated immediately
 		 */
+		netfs_resize_file(netfs_inode(inode), dest_off + len, true);
 		cifs_setsize(inode, dest_off + len);
 	}
 	rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid,