ceph: add support for fscrypt_auth/fscrypt_file to cap messages

Add support for new version 12 cap messages that carry the new
fscrypt_auth and fscrypt_file fields from the inode.

Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 511d1963aa0942a8ab4a3362e582d63b013029e8..a372ed8c6e68ff1d78890984081ee8df59a7c790 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -13,6 +13,7 @@
 #include "super.h"
 #include "mds_client.h"
 #include "cache.h"
+#include "crypto.h"
 #include <linux/ceph/decode.h>
 #include <linux/ceph/messenger.h>
 
@@ -1214,15 +1215,12 @@ struct cap_msg_args {
        umode_t                 mode;
        bool                    inline_data;
        bool                    wake;
+       u32                     fscrypt_auth_len;
+       u32                     fscrypt_file_len;
+       u8                      fscrypt_auth[sizeof(struct ceph_fscrypt_auth)]; // for context
+       u8                      fscrypt_file[sizeof(u64)]; // for size
 };
 
-/*
- * cap struct size + flock buffer size + inline version + inline data size +
- * osd_epoch_barrier + oldest_flush_tid
- */
-#define CAP_MSG_SIZE (sizeof(struct ceph_mds_caps) + \
-                     4 + 8 + 4 + 4 + 8 + 4 + 4 + 4 + 8 + 8 + 4)
-
 /* Marshal up the cap msg to the MDS */
 static void encode_cap_msg(struct ceph_msg *msg, struct cap_msg_args *arg)
 {
@@ -1238,7 +1236,7 @@ static void encode_cap_msg(struct ceph_msg *msg, struct cap_msg_args *arg)
             arg->size, arg->max_size, arg->xattr_version,
             arg->xattr_buf ? (int)arg->xattr_buf->vec.iov_len : 0);
 
-       msg->hdr.version = cpu_to_le16(10);
+       msg->hdr.version = cpu_to_le16(12);
        msg->hdr.tid = cpu_to_le64(arg->flush_tid);
 
        fc = msg->front.iov_base;
@@ -1309,6 +1307,21 @@ static void encode_cap_msg(struct ceph_msg *msg, struct cap_msg_args *arg)
 
        /* Advisory flags (version 10) */
        ceph_encode_32(&p, arg->flags);
+
+       /* dirstats (version 11) - these are r/o on the client */
+       ceph_encode_64(&p, 0);
+       ceph_encode_64(&p, 0);
+
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+       /* fscrypt_auth and fscrypt_file (version 12) */
+       ceph_encode_32(&p, arg->fscrypt_auth_len);
+       ceph_encode_copy(&p, arg->fscrypt_auth, arg->fscrypt_auth_len);
+       ceph_encode_32(&p, arg->fscrypt_file_len);
+       ceph_encode_copy(&p, arg->fscrypt_file, arg->fscrypt_file_len);
+#else /* CONFIG_FS_ENCRYPTION */
+       ceph_encode_32(&p, 0);
+       ceph_encode_32(&p, 0);
+#endif /* CONFIG_FS_ENCRYPTION */
 }
 
 /*
@@ -1430,8 +1443,37 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap,
                }
        }
        arg->flags = flags;
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+       if (ci->fscrypt_auth_len &&
+           WARN_ON_ONCE(ci->fscrypt_auth_len > sizeof(struct ceph_fscrypt_auth))) {
+               /* Don't set this if it's too big */
+               arg->fscrypt_auth_len = 0;
+       } else {
+               arg->fscrypt_auth_len = ci->fscrypt_auth_len;
+               memcpy(arg->fscrypt_auth, ci->fscrypt_auth,
+                       min_t(size_t, ci->fscrypt_auth_len, sizeof(arg->fscrypt_auth)));
+       }
+       /* FIXME: use this to track "real" size */
+       arg->fscrypt_file_len = 0;
+#endif /* CONFIG_FS_ENCRYPTION */
 }
 
+#define CAP_MSG_FIXED_FIELDS (sizeof(struct ceph_mds_caps) + \
+                     4 + 8 + 4 + 4 + 8 + 4 + 4 + 4 + 8 + 8 + 4 + 8 + 8 + 4 + 4)
+
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+static inline int cap_msg_size(struct cap_msg_args *arg)
+{
+       return CAP_MSG_FIXED_FIELDS + arg->fscrypt_auth_len +
+                       arg->fscrypt_file_len;
+}
+#else
+static inline int cap_msg_size(struct cap_msg_args *arg)
+{
+       return CAP_MSG_FIXED_FIELDS;
+}
+#endif /* CONFIG_FS_ENCRYPTION */
+
 /*
  * Send a cap msg on the given inode.
  *
@@ -1442,7 +1484,7 @@ static void __send_cap(struct cap_msg_args *arg, struct ceph_inode_info *ci)
        struct ceph_msg *msg;
        struct inode *inode = &ci->netfs.inode;
 
-       msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, CAP_MSG_SIZE, GFP_NOFS, false);
+       msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, cap_msg_size(arg), GFP_NOFS, false);
        if (!msg) {
                pr_err("error allocating cap msg: ino (%llx.%llx) flushing %s tid %llu, requeuing cap.\n",
                       ceph_vinop(inode), ceph_cap_string(arg->dirty),
@@ -1468,10 +1510,6 @@ static inline int __send_flush_snap(struct inode *inode,
        struct cap_msg_args     arg;
        struct ceph_msg         *msg;
 
-       msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, CAP_MSG_SIZE, GFP_NOFS, false);
-       if (!msg)
-               return -ENOMEM;
-
        arg.session = session;
        arg.ino = ceph_vino(inode).ino;
        arg.cid = 0;
@@ -1509,6 +1547,18 @@ static inline int __send_flush_snap(struct inode *inode,
        arg.flags = 0;
        arg.wake = false;
 
+       /*
+        * No fscrypt_auth changes from a capsnap. It will need
+        * to update fscrypt_file on size changes (TODO).
+        */
+       arg.fscrypt_auth_len = 0;
+       arg.fscrypt_file_len = 0;
+
+       msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, cap_msg_size(&arg),
+                          GFP_NOFS, false);
+       if (!msg)
+               return -ENOMEM;
+
        encode_cap_msg(msg, &arg);
        ceph_con_send(&arg.session->s_con, msg);
        return 0;