apfs: clean up mess for 64-bit inode numbers

Having separate code to deal with inode numbers in 32-bit architectures
has proved unwise; there is no verified performance benefit from this
and now, after several commits with no testing, the 32-bit code won't
even build.  Fix this with a new const qualifier in the argument to
APFS_I(), and from now on just use the 32-bit version of everything.

It's important to always read the inode number with apfs_ino(), to avoid
getting confused and working with the potentially overflowing i_ino;
remove a few remaining instances of this bug.  Also start setting the
number by means of apfs_set_inode(), but don't touch the hacky code for
private-dir; I intend to turn it into a real inode in the future.

Finally, deal with the TODO regarding insert_inode_locked(): define
apfs_insert_inode_locked() as a wrapper to insert_inode_locked4(),
implementing the same functionality as insert_inode_locked() but with
full support for 32-bit architectures.

Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>

fs/apfs/dir.c

@@ -97,7 +97,7 @@ static struct apfs_query *apfs_dentry_lookup(struct inode *dir,
 	struct apfs_sb_info *sbi = APFS_SB(sb);
 	struct apfs_key key;
 	struct apfs_query *query;
-	u64 cnid = dir->i_ino;
+	u64 cnid = apfs_ino(dir);
 	int err;
 
 	apfs_init_drec_hashed_key(sb, cnid, child->name, &key);
@@ -167,7 +167,7 @@ static int apfs_readdir(struct file *file, struct dir_context *ctx)
 	struct apfs_sb_info *sbi = APFS_SB(sb);
 	struct apfs_key key;
 	struct apfs_query *query;
-	u64 cnid = inode->i_ino;
+	u64 cnid = apfs_ino(inode);
 	loff_t pos;
 	int err = 0;
 
@@ -1025,9 +1025,7 @@ int apfs_delete_orphan_link(struct inode *inode)
 	 */
 	parent_info.vfs_inode.i_sb = sb;
 	parent_info.vfs_inode.i_ino = APFS_PRIV_DIR_INO_NUM;
-#if BITS_PER_LONG == 32
-	parent_info.i_ino = APFS_PRIV_DIR_INO_NUM;
-#endif
+	parent_info.i_ino64 = APFS_PRIV_DIR_INO_NUM;
 
 	query = apfs_dentry_lookup(&parent_info.vfs_inode, &qname, &drec);
 	if (IS_ERR(query)) {

fs/apfs/extents.c

@@ -97,7 +97,7 @@ static int apfs_extent_read(struct inode *inode, sector_t iblock,
 	ret = apfs_extent_from_query(query, extent);
 	if (ret) {
 		apfs_alert(sb, "bad extent record for inode 0x%llx",
-			   (unsigned long long) inode->i_ino);
+			   apfs_ino(inode));
 		goto done;
 	}
 

fs/apfs/inode.c

@@ -172,7 +172,7 @@ corrupted:
  * apfs_inode_lookup - Lookup an inode record in the catalog b-tree
  * @inode:	vfs inode to lookup
  *
- * Runs a catalog query for the @inode->i_ino inode record; returns a pointer
+ * Runs a catalog query for the apfs_ino(@inode) inode record; returns a pointer
  * to the query structure on success, or an error pointer in case of failure.
  */
 static struct apfs_query *apfs_inode_lookup(const struct inode *inode)
@@ -199,10 +199,6 @@ static struct apfs_query *apfs_inode_lookup(const struct inode *inode)
 	return ERR_PTR(ret);
 }
 
-#if BITS_PER_LONG == 64
-#define apfs_iget_locked iget_locked
-#else /* 64-bit inode numbers may not fit in the vfs inode */
-
 /**
  * apfs_test_inode - Check if the inode matches a 64-bit inode number
  * @inode:	inode to test
@@ -210,10 +206,9 @@ static struct apfs_query *apfs_inode_lookup(const struct inode *inode)
  */
 static int apfs_test_inode(struct inode *inode, void *cnid)
 {
-	struct apfs_inode_info *ai = APFS_I(inode);
 	u64 *ino = cnid;
 
-	return ai->i_ino == *ino;
+	return apfs_ino(inode) == *ino;
 }
 
 /**
@@ -226,7 +221,7 @@ static int apfs_set_inode(struct inode *inode, void *cnid)
 	struct apfs_inode_info *ai = APFS_I(inode);
 	u64 *ino = cnid;
 
-	ai->i_ino = *ino;
+	ai->i_ino64 = *ino;
 	inode->i_ino = *ino; /* Just discard the higher bits here... */
 	return 0;
 }
@@ -236,15 +231,14 @@ static int apfs_set_inode(struct inode *inode, void *cnid)
  * @sb:		filesystem superblock
  * @cnid:	64-bit inode number
  *
- * Works the same as iget_locked(), but supports 64-bit inode numbers.
+ * Works the same as iget_locked(), but can handle 64-bit inode numbers on
+ * 32-bit architectures.
  */
 static struct inode *apfs_iget_locked(struct super_block *sb, u64 cnid)
 {
 	return iget5_locked(sb, cnid, apfs_test_inode, apfs_set_inode, &cnid);
 }
 
-#endif /* BITS_PER_LONG == 64 */
-
 /**
  * apfs_iget - Populate inode structures with metadata from disk
  * @sb:		filesystem superblock
@@ -357,7 +351,7 @@ static int apfs_build_inode_val(struct inode *inode, struct qstr *qname,
 		return -ENOMEM;
 
 	val->parent_id = cpu_to_le64(APFS_I(inode)->i_parent_id);
-	val->private_id = cpu_to_le64(inode->i_ino);
+	val->private_id = cpu_to_le64(apfs_ino(inode));
 
 	val->mod_time = apfs_timestamp(inode->i_mtime);
 	val->create_time = val->change_time = val->access_time = val->mod_time;
@@ -573,6 +567,20 @@ out_clear:
 	clear_inode(inode);
 }
 
+/**
+ * apfs_insert_inode_locked - Wrapper for insert_inode_locked4()
+ * @inode: vfs inode to insert in cache
+ *
+ * Works the same as insert_inode_locked(), but can handle 64-bit inode numbers
+ * on 32-bit architectures.
+ */
+static int apfs_insert_inode_locked(struct inode *inode)
+{
+	u64 cnid = apfs_ino(inode);
+
+	return insert_inode_locked4(inode, cnid, apfs_test_inode, &cnid);
+}
+
 /**
  * apfs_new_inode - Create a new in-memory inode
  * @dir:	parent inode
@@ -601,10 +609,7 @@ struct inode *apfs_new_inode(struct inode *dir, umode_t mode, dev_t rdev)
 
 	cnid = le64_to_cpu(vsb_raw->apfs_next_obj_id);
 	le64_add_cpu(&vsb_raw->apfs_next_obj_id, 1);
-	inode->i_ino = cnid;
-#if BITS_PER_LONG == 32
-	ai->ino = cnid;
-#endif
+	apfs_set_inode(inode, &cnid);
 	inode_init_owner(inode, dir, mode); /* TODO: handle override */
 	ai->i_parent_id = apfs_ino(dir);
 	set_nlink(inode, 1);
@@ -623,8 +628,7 @@ struct inode *apfs_new_inode(struct inode *dir, umode_t mode, dev_t rdev)
 	else
 		le64_add_cpu(&vsb_raw->apfs_num_other_fsobjects, 1);
 
-	/* TODO: use insert_inode_locked4() on 32-bit architectures */
-	if (insert_inode_locked(inode)) {
+	if (apfs_insert_inode_locked(inode)) {
 		/* The inode number should have been free, but wasn't */
 		make_bad_inode(inode);
 		iput(inode);

fs/apfs/inode.h

@@ -117,6 +117,7 @@ struct apfs_dstream {
  * APFS inode data in memory
  */
 struct apfs_inode_info {
+	u64			i_ino64;	 /* 32-bit-safe inode number */
 	u64			i_parent_id;	 /* ID of primary parent */
 	u64			i_extent_id;	 /* ID of the extent records */
 	struct apfs_file_extent	i_cached_extent; /* Latest extent record */
@@ -124,14 +125,10 @@ struct apfs_inode_info {
 	struct timespec64	i_crtime;	 /* Time of creation */
 	u32			i_nchildren;	 /* Child count for directory */
 
-#if BITS_PER_LONG == 32
-	/* This is the actual inode number; vfs_inode.i_ino could overflow */
-	u64			i_ino;
-#endif
 	struct inode vfs_inode;
 };
 
-static inline struct apfs_inode_info *APFS_I(struct inode *inode)
+static inline struct apfs_inode_info *APFS_I(const struct inode *inode)
 {
 	return container_of(inode, struct apfs_inode_info, vfs_inode);
 }
@@ -144,11 +141,7 @@ static inline struct apfs_inode_info *APFS_I(struct inode *inode)
  */
 static inline u64 apfs_ino(const struct inode *inode)
 {
-#if BITS_PER_LONG == 64
-	return inode->i_ino;
-#else
-	return APFS_I(inode)->i_ino;
-#endif
+	return APFS_I(inode)->i_ino64;
 }
 
 extern struct inode *apfs_iget(struct super_block *sb, u64 cnid);

fs/apfs/symlink.c

@@ -58,7 +58,7 @@ static const char *apfs_get_link(struct dentry *dentry, struct inode *inode,
 	if (size == 0 || *(target + size - 1) != 0) {
 		/* Target path must be NULL-terminated */
 		apfs_alert(sb, "bad link target in inode 0x%llx",
-			   (unsigned long long) inode->i_ino);
+			   apfs_ino(inode));
 		err = -EFSCORRUPTED;
 		goto fail;
 	}

fs/apfs/xattr.c

@@ -137,7 +137,7 @@ static int apfs_xattr_extents_read(struct inode *parent,
 		err = apfs_extent_from_query(query, &ext);
 		if (err) {
 			apfs_alert(sb, "bad extent for xattr in inode 0x%llx",
-				   (unsigned long long) parent->i_ino);
+				   apfs_ino(parent));
 			ret = err;
 			goto done;
 		}
@@ -213,7 +213,7 @@ int __apfs_xattr_get(struct inode *inode, const char *name, void *buffer,
 	struct apfs_key key;
 	struct apfs_query *query;
 	struct apfs_xattr xattr;
-	u64 cnid = inode->i_ino;
+	u64 cnid = apfs_ino(inode);
 	int ret;
 
 	apfs_init_xattr_key(cnid, name, &key);
@@ -296,7 +296,7 @@ ssize_t apfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 	struct apfs_sb_info *sbi = APFS_SB(sb);
 	struct apfs_key key;
 	struct apfs_query *query;
-	u64 cnid = inode->i_ino;
+	u64 cnid = apfs_ino(inode);
 	size_t free = size;
 	ssize_t ret;