[PATCH] hfsplus: add HFSX subfolder count support

[Sergei Antonov <saproj@gmail.com>]

This patch adds support for HFSX 'HasFolderCount' flag and a corresponding 'folderCount' field in folder records. (For reference see HFS_FOLDERCOUNT and kHFSHasFolderCountBit/kHFSHasFolderCountMask in Apple's source code.)

Ignoring subfolder count leads to fs errors found by Mac:
...
Checking catalog hierarchy.
HasFolderCount flag needs to be set (id = 105)
(It should be 0x10 instead of 0)
Incorrect folder count in a directory (id = 2)
(It should be 7 instead of 6)
...

Steps to reproduce:
 Format with "newfs_hfs -s /dev/diskXXX".
 Mount in Linux.
 Create a new directory in root.
 Unmount.
 Run "fsck_hfs /dev/diskXXX".

Signed-off-by: Sergei Antonov <saproj@gmail.com>
---
 fs/hfsplus/catalog.c     |    7 +++++++
 fs/hfsplus/hfsplus_fs.h  |    1 +
 fs/hfsplus/hfsplus_raw.h |    3 ++-
 fs/hfsplus/inode.c       |    3 +++
 4 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/fs/hfsplus/catalog.c b/fs/hfsplus/catalog.c
index 968ce41..bc770303 100644
--- a/fs/hfsplus/catalog.c
+++ b/fs/hfsplus/catalog.c
@@ -103,12 +103,15 @@ static int hfsplus_cat_build_record(hfsplus_cat_entry *entry,
 		folder = &entry->folder;
 		memset(folder, 0, sizeof(*folder));
 		folder->type = cpu_to_be16(HFSPLUS_FOLDER);
+		if (test_bit(HFSPLUS_SB_HFSX, &sbi->flags))
+			folder->flags = cpu_to_be16(HFSPLUS_HAS_FOLDER_COUNT);
 		folder->id = cpu_to_be32(inode->i_ino);
 		HFSPLUS_I(inode)->create_date =
 			folder->create_date =
 			folder->content_mod_date =
 			folder->attribute_mod_date =
 			folder->access_date = hfsp_now2mt();
+		HFSPLUS_I(inode)->folder_count = 0;
 		hfsplus_cat_set_perms(inode, &folder->permissions);
 		if (inode == sbi->hidden_dir)
 			/* invisible and namelocked */
@@ -247,6 +250,8 @@ int hfsplus_create_cat(u32 cnid, struct inode *dir,
 		goto err1;
 
 	dir->i_size++;
+	if (S_ISDIR(inode->i_mode))
+		HFSPLUS_I(dir)->folder_count++;
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
 	hfsplus_mark_inode_dirty(dir, HFSPLUS_I_CAT_DIRTY);
 
@@ -336,6 +341,8 @@ int hfsplus_delete_cat(u32 cnid, struct inode *dir, struct qstr *str)
 		goto out;
 
 	dir->i_size--;
+	if (type == HFSPLUS_FOLDER)
+		HFSPLUS_I(dir)->folder_count--;
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
 	hfsplus_mark_inode_dirty(dir, HFSPLUS_I_CAT_DIRTY);
 
diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index 08846425b..2c22cd2 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -242,6 +242,7 @@ struct hfsplus_inode_info {
 	 */
 	sector_t fs_blocks;
 	u8 userflags;		/* BSD user file flags */
+	u32 folder_count;	/* subfolder count if HFSPLUS_HAS_FOLDER_COUNT is set */
 	struct list_head open_dir_list;
 	loff_t phys_size;
 
diff --git a/fs/hfsplus/hfsplus_raw.h b/fs/hfsplus/hfsplus_raw.h
index 8ffb3a8..6529629 100644
--- a/fs/hfsplus/hfsplus_raw.h
+++ b/fs/hfsplus/hfsplus_raw.h
@@ -261,7 +261,7 @@ struct hfsplus_cat_folder {
 	struct DInfo user_info;
 	struct DXInfo finder_info;
 	__be32 text_encoding;
-	u32 reserved;
+	__be32 folder_count;	/* Number of subfolders when HFSPLUS_HAS_FOLDER_COUNT is set. Reserved otherwise. */
 } __packed;
 
 /* HFS file info (stolen from hfs.h) */
@@ -306,6 +306,7 @@ struct hfsplus_cat_file {
 #define HFSPLUS_FILE_THREAD_EXISTS	0x0002
 #define HFSPLUS_XATTR_EXISTS		0x0004
 #define HFSPLUS_ACL_EXISTS		0x0008
+#define HFSPLUS_HAS_FOLDER_COUNT	0x0010
 
 /* HFS+ catalog thread (part of a cat_entry) */
 struct hfsplus_cat_thread {
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index fa929f3..7d18221 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -494,6 +494,7 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
 		inode->i_ctime = hfsp_mt2ut(folder->attribute_mod_date);
 		HFSPLUS_I(inode)->create_date = folder->create_date;
 		HFSPLUS_I(inode)->fs_blocks = 0;
+		HFSPLUS_I(inode)->folder_count = be32_to_cpu(folder->folder_count);
 		inode->i_op = &hfsplus_dir_inode_operations;
 		inode->i_fop = &hfsplus_dir_operations;
 	} else if (type == HFSPLUS_FILE) {
@@ -566,6 +567,8 @@ int hfsplus_cat_write_inode(struct inode *inode)
 		folder->content_mod_date = hfsp_ut2mt(inode->i_mtime);
 		folder->attribute_mod_date = hfsp_ut2mt(inode->i_ctime);
 		folder->valence = cpu_to_be32(inode->i_size - 2);
+		if (folder->flags & cpu_to_be16(HFSPLUS_HAS_FOLDER_COUNT))
+			folder->folder_count = cpu_to_be32(HFSPLUS_I(inode)->folder_count);
 		hfs_bnode_write(fd.bnode, &entry, fd.entryoffset,
 					 sizeof(struct hfsplus_cat_folder));
 	} else if (HFSPLUS_IS_RSRC(inode)) {
-- 
1.7.10.2