[RFC PATCH v11 08/51] ceph: add support for fscrypt_auth/fscrypt_file to cap messages

Jeff Layton
2022-03-22T14:18:21Z

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

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/ceph/caps.c | 76 +++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 63 insertions(+), 13 deletions(-)

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 7d8ef67a1032..b0b7688331b4 100644
--- 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 isn't right size */
+ 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->vfs_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;
--
2.35.1