[PATCH 1/4] nfs: store the full NFS fileid in inode->i_ino

[Jeff Layton <jlayton@kernel.org>]

Now that inode->i_ino is a 64-bit value, store the full NFS fileid in
it directly instead of an XOR-folded hash. This makes NFS_FILEID() and
set_nfs_fileid() operate on inode->i_ino rather than the separate
nfsi->fileid field.

Since iget5_locked() and ilookup5() now accept a u64 hashval, pass the
full fileid as the hash parameter directly.

Convert direct nfsi->fileid accesses in nfs_check_inode_attributes(),
nfs_update_inode(), and nfs_same_file() to use inode->i_ino.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfs/dir.c           |  2 +-
 fs/nfs/inode.c         | 25 ++++++++++---------------
 include/linux/nfs_fs.h |  4 ++--
 3 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index e9ce1883288c..5f8c3ea0bce3 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -650,7 +650,7 @@ int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
 		return 0;
 
 	nfsi = NFS_I(inode);
-	if (entry->fattr->fileid != nfsi->fileid)
+	if (entry->fattr->fileid != inode->i_ino)
 		return 0;
 	if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0)
 		return 0;
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e26030e73696..dd9e378c36fb 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -66,10 +66,10 @@ static int nfs_update_inode(struct inode *, struct nfs_fattr *);
 
 static struct kmem_cache * nfs_inode_cachep;
 
-static inline unsigned long
+static inline u64
 nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
 {
-	return nfs_fileid_to_ino_t(fattr->fileid);
+	return fattr->fileid;
 }
 
 int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
@@ -313,8 +313,7 @@ struct nfs_find_desc {
 };
 
 /*
- * In NFSv3 we can have 64bit inode numbers. In order to support
- * this, and re-exported directories (also seen in NFSv2)
+ * For re-exported directories (also seen in NFSv2)
  * we are forced to allow 2 different inodes to have the same
  * i_ino.
  */
@@ -413,7 +412,7 @@ nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
 		.fattr	= fattr,
 	};
 	struct inode *inode;
-	unsigned long hash;
+	u64 hash;
 
 	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
 	    !(fattr->valid & NFS_ATTR_FATTR_TYPE))
@@ -456,7 +455,7 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
 	};
 	struct inode *inode = ERR_PTR(-ENOENT);
 	u64 fattr_supported = NFS_SB(sb)->fattr_valid;
-	unsigned long hash;
+	u64 hash;
 
 	nfs_attr_check_mountpoint(sb, fattr);
 
@@ -479,10 +478,6 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
 		struct nfs_inode *nfsi = NFS_I(inode);
 		unsigned long now = jiffies;
 
-		/* We set i_ino for the few things that still rely on it,
-		 * such as stat(2) */
-		inode->i_ino = hash;
-
 		/* We can't support update_atime(), since the server will reset it */
 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
 		inode->i_mode = fattr->mode;
@@ -1672,10 +1667,10 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat
 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
 			return 0;
 	/* Has the inode gone and changed behind our back? */
-	} else if (nfsi->fileid != fattr->fileid) {
+	} else if (inode->i_ino != fattr->fileid) {
 		/* Is this perhaps the mounted-on fileid? */
 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
-		    nfsi->fileid == fattr->mounted_on_fileid)
+		    inode->i_ino == fattr->mounted_on_fileid)
 			return 0;
 		return -ESTALE;
 	}
@@ -2262,15 +2257,15 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
 			return 0;
 	/* Has the inode gone and changed behind our back? */
-	} else if (nfsi->fileid != fattr->fileid) {
+	} else if (inode->i_ino != fattr->fileid) {
 		/* Is this perhaps the mounted-on fileid? */
 		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
-		    nfsi->fileid == fattr->mounted_on_fileid)
+		    inode->i_ino == fattr->mounted_on_fileid)
 			return 0;
 		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
 			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
 			NFS_SERVER(inode)->nfs_client->cl_hostname,
-			inode->i_sb->s_id, (long long)nfsi->fileid,
+			inode->i_sb->s_id, (long long)inode->i_ino,
 			(long long)fattr->fileid);
 		goto out_err;
 	}
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 4623262da3c0..8e48053b3069 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -396,12 +396,12 @@ static inline int NFS_STALE(const struct inode *inode)
 
 static inline __u64 NFS_FILEID(const struct inode *inode)
 {
-	return NFS_I(inode)->fileid;
+	return inode->i_ino;
 }
 
 static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
 {
-	NFS_I(inode)->fileid = fileid;
+	inode->i_ino = fileid;
 }
 
 static inline void nfs_mark_for_revalidate(struct inode *inode)

-- 
2.54.0