Allow setting per-file compression via SMB2/3

Allow cifs/smb2/smb3 to return whether or not a file is compressed
via lsattr, and allow SMB2/SMB3 to set the per-file compression
flag ("chattr +c filename" on an smb3 mount).

Windows users often set the compressed flag (it can be
done from the desktop and file manager).  David Disseldorp
has patches to Samba server to support this (at least on btrfs)
which are complementary to this

Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 6e1868611233..bbafa12e83b2 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1247,6 +1247,33 @@ ioctl_exit:
 	return rc;
 }
 
+/*
+ *   Individual callers to ioctl worker function follow
+ */
+
+int
+SMB2_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
+		     u64 persistent_fid, u64 volatile_fid)
+{
+	int rc;
+	char *res_key = NULL;
+	struct  compress_ioctl fsctl_input;
+	char *ret_data = NULL;
+
+	fsctl_input.CompressionState =
+			__constant_cpu_to_le16(COMPRESSION_FORMAT_DEFAULT);
+
+	rc = SMB2_ioctl(xid, tcon, persistent_fid, volatile_fid,
+			FSCTL_SET_COMPRESSION, true /* is_fsctl */,
+			(char *)&fsctl_input /* data input */,
+			2 /* in data len */, &ret_data /* out data */, NULL);
+
+	cifs_dbg(FYI, "set compression rc %d\n", rc);
+	kfree(res_key);
+
+	return rc;
+}
+
 int
 SMB2_close(const unsigned int xid, struct cifs_tcon *tcon,
 	   u64 persistent_fid, u64 volatile_fid)