[PATCH v13 39/59] ceph: size handling for encrypted inodes in cap updates

Jeff Layton
2022-04-05T21:09:54Z

Transmit the rounded-up size as the normal size, and fill out the
fscrypt_file field with the real file size.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/ceph/caps.c | 43 +++++++++++++++++++++++++------------------
fs/ceph/crypto.h | 4 ++++
2 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 22bf3e2696cb..cb5cdf2260ad 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1215,10 +1215,9 @@ struct cap_msg_args {
umode_t mode;
bool inline_data;
bool wake;
+ bool encrypted;
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
};

/* Marshal up the cap msg to the MDS */
@@ -1253,7 +1252,12 @@ static void encode_cap_msg(struct ceph_msg *msg, struct cap_msg_args *arg)
fc->ino = cpu_to_le64(arg->ino);
fc->snap_follows = cpu_to_le64(arg->follows);

- fc->size = cpu_to_le64(arg->size);
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+ if (arg->encrypted)
+ fc->size = cpu_to_le64(round_up(arg->size, CEPH_FSCRYPT_BLOCK_SIZE));
+ else
+#endif
+ fc->size = cpu_to_le64(arg->size);
fc->max_size = cpu_to_le64(arg->max_size);
ceph_encode_timespec64(&fc->mtime, &arg->mtime);
ceph_encode_timespec64(&fc->atime, &arg->atime);
@@ -1313,11 +1317,17 @@ static void encode_cap_msg(struct ceph_msg *msg, struct cap_msg_args *arg)
ceph_encode_64(&p, 0);

#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
- /* fscrypt_auth and fscrypt_file (version 12) */
+ /*
+ * fscrypt_auth and fscrypt_file (version 12)
+ *
+ * fscrypt_auth holds the crypto context (if any). fscrypt_file
+ * tracks the real i_size as an __le64 field (and we use a rounded-up
+ * i_size in * the traditional size field).
+ */
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);
+ ceph_encode_32(&p, sizeof(__le64));
+ ceph_encode_64(&p, arg->size);
#else /* CONFIG_FS_ENCRYPTION */
ceph_encode_32(&p, 0);
ceph_encode_32(&p, 0);
@@ -1389,7 +1399,6 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap,
arg->follows = flushing ? ci->i_head_snapc->seq : 0;
arg->flush_tid = flush_tid;
arg->oldest_flush_tid = oldest_flush_tid;
-
arg->size = i_size_read(inode);
ci->i_reported_size = arg->size;
arg->max_size = ci->i_wanted_max_size;
@@ -1443,6 +1452,7 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap,
}
}
arg->flags = flags;
+ arg->encrypted = IS_ENCRYPTED(inode);
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
if (ci->fscrypt_auth_len &&
WARN_ON_ONCE(ci->fscrypt_auth_len > sizeof(struct ceph_fscrypt_auth))) {
@@ -1453,21 +1463,21 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap,
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 */
}

+#if IS_ENABLED(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)
+ 4 + 8 + 4 + 4 + 8 + 4 + 4 + 4 + 8 + 8 + 4 + 8 + 8 + 4 + 4 + 8)

-#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;
+ return CAP_MSG_FIXED_FIELDS + arg->fscrypt_auth_len;
}
#else
+#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)
+
static inline int cap_msg_size(struct cap_msg_args *arg)
{
return CAP_MSG_FIXED_FIELDS;
@@ -1546,13 +1556,10 @@ static inline int __send_flush_snap(struct inode *inode,
arg.inline_data = capsnap->inline_data;
arg.flags = 0;
arg.wake = false;
+ arg.encrypted = IS_ENCRYPTED(inode);

- /*
- * No fscrypt_auth changes from a capsnap. It will need
- * to update fscrypt_file on size changes (TODO).
- */
+ /* No fscrypt_auth changes from a capsnap.*/
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);
diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h
index 080905b0c73c..56a61ba64edc 100644
--- a/fs/ceph/crypto.h
+++ b/fs/ceph/crypto.h
@@ -9,6 +9,10 @@
#include <crypto/sha2.h>
#include <linux/fscrypt.h>

+#define CEPH_FSCRYPT_BLOCK_SHIFT 12
+#define CEPH_FSCRYPT_BLOCK_SIZE (_AC(1, UL) << CEPH_FSCRYPT_BLOCK_SHIFT)
+#define CEPH_FSCRYPT_BLOCK_MASK (~(CEPH_FSCRYPT_BLOCK_SIZE-1))
+
struct ceph_fs_client;
struct ceph_acl_sec_ctx;
struct ceph_mds_request;
--
2.35.1