From 001d874c1978690301da8fbd34ec21a61aaa72af Mon Sep 17 00:00:00 2001 From: Vyacheslav Dubeyko Date: Fri, 28 Sep 2012 10:20:41 +1000 Subject: [PATCH] hfsplus: add on-disk layout declarations related to attributes tree Current mainline implementation of hfsplus file system driver treats as extended attributes only two fields (fdType and fdCreator) of user_info field in file description record (struct hfsplus_cat_file). It is possible to get or set only these two fields as extended attributes. But HFS+ treats as com.apple.FinderInfo extended attribute an union of user_info and finder_info fields as for file (struct hfsplus_cat_file) as for folder (struct hfsplus_cat_folder). Moreover, current mainline implementation of hfsplus file system driver doesn't support special metadata file - attributes tree. Mac OS X 10.4 and later support extended attributes by making use of the HFS+ filesystem Attributes file B*-tree feature which allows for named forks. Mac OS X supports only inline extended attributes, limiting their size to 3802 bytes. Any regular file may have a list of extended attributes. HFS+ supports an arbitrary number of named forks. Each attribute is denoted by a name and the associated data. The name is a null-terminated Unicode string. It is possible to list, to get, to set, and to remove extended attributes from files or directories. It exists some peculiarity during getting of extended attributes list by means of getfattr utility. The getfattr utility expects prefix "user." before any extended attribute's name. So, it ignores any names that don't contained such prefix. Such behavior of getfattr utility results in unexpected empty output of extended attributes list even in the case when file (or folder) contains extended attributes. It needs to use empty string as regular expression pattern for names matching (getfattr --match=""). For support of extended attributes in HFS+: 1. It was added necessary on-disk layout declarations related to Attributes tree into hfsplus_raw.h file. 2. It was added attributes.c file with implementation of functionality of manipulation by records in Attributes tree. 3. It was reworked hfsplus_listxattr, hfsplus_getxattr, hfsplus_setxattr functions in ioctl.c. Moreover, it was added hfsplus_removexattr method. This patch: Add all neccessary on-disk layout declarations related to attributes file. Signed-off-by: Vyacheslav Dubeyko Reported-by: Hin-Tak Leung Cc: Al Viro Cc: Christoph Hellwig Cc: Jan Kara Signed-off-by: Andrew Morton --- fs/hfsplus/hfsplus_raw.h | 72 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 67 insertions(+), 5 deletions(-) diff --git a/fs/hfsplus/hfsplus_raw.h b/fs/hfsplus/hfsplus_raw.h index 921967e5abb1..56f393f906dd 100644 --- a/fs/hfsplus/hfsplus_raw.h +++ b/fs/hfsplus/hfsplus_raw.h @@ -52,13 +52,21 @@ typedef __be32 hfsplus_cnid; typedef __be16 hfsplus_unichr; +#define HFSPLUS_MAX_STRLEN 255 +#define HFSPLUS_ATTR_MAX_STRLEN 127 + +#define HFSPLUS_STRING(name, max_len) \ +struct hfsplus_##name { \ + __be16 length; \ + hfsplus_unichr unicode[max_len]; \ +} __packed; \ + /* A "string" as used in filenames, etc. */ -struct hfsplus_unistr { - __be16 length; - hfsplus_unichr unicode[255]; -} __packed; +HFSPLUS_STRING(unistr, HFSPLUS_MAX_STRLEN) -#define HFSPLUS_MAX_STRLEN 255 +/* A "string" is used in attributes file + for name of extended attribute */ +HFSPLUS_STRING(attr_unistr, HFSPLUS_ATTR_MAX_STRLEN) /* POSIX permissions */ struct hfsplus_perm { @@ -291,6 +299,8 @@ struct hfsplus_cat_file { /* File attribute bits */ #define HFSPLUS_FILE_LOCKED 0x0001 #define HFSPLUS_FILE_THREAD_EXISTS 0x0002 +#define HFSPLUS_XATTR_EXISTS 0x0004 +#define HFSPLUS_ACL_EXISTS 0x0008 /* HFS+ catalog thread (part of a cat_entry) */ struct hfsplus_cat_thread { @@ -327,11 +337,63 @@ struct hfsplus_ext_key { #define HFSPLUS_EXT_KEYLEN sizeof(struct hfsplus_ext_key) +#define HFSPLUS_XATTR_FINDER_INFO_NAME "com.apple.FinderInfo" +#define HFSPLUS_XATTR_ACL_NAME "com.apple.system.Security" + +#define HFSPLUS_ATTR_INLINE_DATA 0x10 +#define HFSPLUS_ATTR_FORK_DATA 0x20 +#define HFSPLUS_ATTR_EXTENTS 0x30 + +/* HFS+ attributes tree key */ +struct hfsplus_attr_key { + __be16 key_len; + __be16 pad; + hfsplus_cnid cnid; + __be32 start_block; + struct hfsplus_attr_unistr key_name; +} __packed; + +#define HFSPLUS_ATTR_KEYLEN sizeof(struct hfsplus_attr_key) + +/* HFS+ fork data attribute */ +struct hfsplus_attr_fork_data { + __be32 record_type; + __be32 reserved; + struct hfsplus_fork_raw the_fork; +} __packed; + +/* HFS+ extension attribute */ +struct hfsplus_attr_extents { + __be32 record_type; + __be32 reserved; + struct hfsplus_extent extents; +} __packed; + +#define HFSPLUS_MAX_INLINE_DATA_SIZE 3802 + +/* HFS+ attribute inline data */ +struct hfsplus_attr_inline_data { + __be32 record_type; + __be32 reserved1; + u8 reserved2[6]; + __be16 length; + u8 raw_bytes[HFSPLUS_MAX_INLINE_DATA_SIZE]; +} __packed; + +/* A data record in the attributes tree */ +typedef union { + __be32 record_type; + struct hfsplus_attr_fork_data fork_data; + struct hfsplus_attr_extents extents; + struct hfsplus_attr_inline_data inline_data; +} __packed hfsplus_attr_entry; + /* HFS+ generic BTree key */ typedef union { __be16 key_len; struct hfsplus_cat_key cat; struct hfsplus_ext_key ext; + struct hfsplus_attr_key attr; } __packed hfsplus_btree_key; #endif -- 2.39.5