[PATCH v4 12/12] fs/ceph: remove redundant inode number from ceph_inode_info

[Max Kellermann <max.kellermann@ionos.com>]

On 64 bit systems, ceph_vino_to_ino_t() is a no-op, and inode.i_ino is
the same as ceph_vino.ino.

This reduces the size of `struct ceph_inode_info` by 8 bytes.

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
---
 fs/ceph/cache.c |  4 +++-
 fs/ceph/inode.c |  9 +++++++++
 fs/ceph/super.h | 23 +++++++++++++++++++++++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c
index f678bab189d8..289615e58196 100644
--- a/fs/ceph/cache.c
+++ b/fs/ceph/cache.c
@@ -16,6 +16,7 @@ void ceph_fscache_register_inode_cookie(struct inode *inode)
 {
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	struct ceph_fs_client *fsc = ceph_inode_to_fs_client(inode);
+	struct ceph_vino vino;
 
 	/* No caching for filesystem? */
 	if (!fsc->fscache)
@@ -31,9 +32,10 @@ void ceph_fscache_register_inode_cookie(struct inode *inode)
 
 	WARN_ON_ONCE(ci->netfs.cache);
 
+	vino = ceph_vino(inode);
 	ci->netfs.cache =
 		fscache_acquire_cookie(fsc->fscache, 0,
-				       &ci->i_vino, sizeof(ci->i_vino),
+				       &vino, sizeof(vino),
 				       &ci->i_version, sizeof(ci->i_version),
 				       i_size_read(inode));
 	if (ci->netfs.cache)
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index aba98975a8a3..4faac8db5f00 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -44,11 +44,20 @@ static void ceph_inode_work(struct work_struct *work);
  */
 static int ceph_set_ino_cb(struct inode *inode, void *data)
 {
+#if BITS_PER_LONG >= 64
+	const struct ceph_vino *vino = data;
+#endif
 	struct ceph_inode_info *ci = ceph_inode(inode);
 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb);
 
+#if BITS_PER_LONG >= 64
+	inode->i_ino = vino->ino;
+	ci->i_snap = vino->snap;
+#else
 	ci->i_vino = *(struct ceph_vino *)data;
 	inode->i_ino = ceph_vino_to_ino_t(ci->i_vino);
+#endif
+
 	inode_set_iversion_raw(inode, 0);
 	percpu_counter_inc(&mdsc->metric.total_inodes);
 
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 660125d94f8e..e5ab1b83a84d 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -378,7 +378,15 @@ struct ceph_inode_xattrs_info {
  */
 struct ceph_inode_info {
 	struct netfs_inode netfs; /* Netfslib context and vfs inode */
+
+#if BITS_PER_LONG >= 64
+	/* on 64 bit systems, the full Ceph inode number is stored in
+	 * netfs.inode.i_ino
+	 */
+	u64 i_snap;
+#else
 	struct ceph_vino i_vino;   /* ceph ino + snap */
+#endif
 
 	spinlock_t i_ceph_lock;
 
@@ -570,7 +578,14 @@ ceph_inode_to_client(const struct inode *inode)
 static inline struct ceph_vino
 ceph_vino(const struct inode *inode)
 {
+#if BITS_PER_LONG >= 64
+	return (struct ceph_vino){
+		.ino = inode->i_ino,
+		.snap = ceph_inode(inode)->i_snap,
+	};
+#else
 	return ceph_inode(inode)->i_vino;
+#endif
 }
 
 static inline u32 ceph_ino_to_ino32(u64 vino)
@@ -600,12 +615,20 @@ static inline ino_t ceph_vino_to_ino_t(const struct ceph_vino vino)
 
 static inline u64 ceph_ino(const struct inode *inode)
 {
+#if BITS_PER_LONG >= 64
+	return inode->i_ino;
+#else
 	return ceph_inode(inode)->i_vino.ino;
+#endif
 }
 
 static inline u64 ceph_snap(const struct inode *inode)
 {
+#if BITS_PER_LONG >= 64
+	return ceph_inode(inode)->i_snap;
+#else
 	return ceph_inode(inode)->i_vino.snap;
+#endif
 }
 
 /**
-- 
2.47.3