[PATCH 5.15 044/121] NFS: Save some space in the inode

Greg Kroah-Hartman
2022-09-13T14:36:34Z

From: Trond Myklebust <trond.myklebust@hammerspace.com>

[ Upstream commit e591b298d7ecb851e200f65946e3d53fe78a3c4f ]

Save some space in the nfs_inode by setting up an anonymous union with
the fields that are peculiar to a specific type of filesystem object.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/inode.c | 26 ++++++++++++++++++--------
include/linux/nfs_fs.h | 42 ++++++++++++++++++++++++------------------
2 files changed, 42 insertions(+), 26 deletions(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index cb407af9e9e92..dc057ab6b30d1 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -431,6 +431,22 @@ nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
return inode;
}

+static void nfs_inode_init_regular(struct nfs_inode *nfsi)
+{
+ atomic_long_set(&nfsi->nrequests, 0);
+ INIT_LIST_HEAD(&nfsi->commit_info.list);
+ atomic_long_set(&nfsi->commit_info.ncommit, 0);
+ atomic_set(&nfsi->commit_info.rpcs_out, 0);
+ mutex_init(&nfsi->commit_mutex);
+}
+
+static void nfs_inode_init_dir(struct nfs_inode *nfsi)
+{
+ nfsi->cache_change_attribute = 0;
+ memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
+ init_rwsem(&nfsi->rmdir_sem);
+}
+
/*
* This is our front-end to iget that looks up inodes by file handle
* instead of inode number.
@@ -485,10 +501,12 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, st
if (S_ISREG(inode->i_mode)) {
inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
inode->i_data.a_ops = &nfs_file_aops;
+ nfs_inode_init_regular(nfsi);
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
inode->i_fop = &nfs_dir_operations;
inode->i_data.a_ops = &nfs_dir_aops;
+ nfs_inode_init_dir(nfsi);
/* Deal with crossing mountpoints */
if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
@@ -514,7 +532,6 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, st
inode->i_uid = make_kuid(&init_user_ns, -2);
inode->i_gid = make_kgid(&init_user_ns, -2);
inode->i_blocks = 0;
- memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
nfsi->write_io = 0;
nfsi->read_io = 0;

@@ -2282,14 +2299,7 @@ static void init_once(void *foo)
INIT_LIST_HEAD(&nfsi->open_files);
INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
- INIT_LIST_HEAD(&nfsi->commit_info.list);
- atomic_long_set(&nfsi->nrequests, 0);
- atomic_long_set(&nfsi->commit_info.ncommit, 0);
- atomic_set(&nfsi->commit_info.rpcs_out, 0);
- init_rwsem(&nfsi->rmdir_sem);
- mutex_init(&nfsi->commit_mutex);
nfs4_init_once(nfsi);
- nfsi->cache_change_attribute = 0;
}

static int __init nfs_init_inodecache(void)
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index be8625d8a10a7..d0855352cd6fc 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -155,33 +155,39 @@ struct nfs_inode {
unsigned long attrtimeo_timestamp;

unsigned long attr_gencount;
- /* "Generation counter" for the attribute cache. This is
- * bumped whenever we update the metadata on the
- * server.
- */
- unsigned long cache_change_attribute;

struct rb_root access_cache;
struct list_head access_cache_entry_lru;
struct list_head access_cache_inode_lru;

- /*
- * This is the cookie verifier used for NFSv3 readdir
- * operations
- */
- __be32 cookieverf[NFS_DIR_VERIFIER_SIZE];
-
- atomic_long_t nrequests;
- struct nfs_mds_commit_info commit_info;
+ union {
+ /* Directory */
+ struct {
+ /* "Generation counter" for the attribute cache.
+ * This is bumped whenever we update the metadata
+ * on the server.
+ */
+ unsigned long cache_change_attribute;
+ /*
+ * This is the cookie verifier used for NFSv3 readdir
+ * operations
+ */
+ __be32 cookieverf[NFS_DIR_VERIFIER_SIZE];
+ /* Readers: in-flight sillydelete RPC calls */
+ /* Writers: rmdir */
+ struct rw_semaphore rmdir_sem;
+ };
+ /* Regular file */
+ struct {
+ atomic_long_t nrequests;
+ struct nfs_mds_commit_info commit_info;
+ struct mutex commit_mutex;
+ };
+ };

/* Open contexts for shared mmap writes */
struct list_head open_files;

- /* Readers: in-flight sillydelete RPC calls */
- /* Writers: rmdir */
- struct rw_semaphore rmdir_sem;
- struct mutex commit_mutex;
-
#if IS_ENABLED(CONFIG_NFS_V4)
struct nfs4_cached_acl *nfs4_acl;
/* NFSv4 state */
--
2.35.1