| 1 | /*
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| 2 | File: linux/ext2_ext_attr.h
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| 3 |
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| 4 | On-disk format of extended attributes for the ext2 filesystem.
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| 5 |
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| 6 | (C) 2000 Andreas Gruenbacher, <a.gruenbacher@computer.org>
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| 7 | */
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| 8 |
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| 9 | /* Magic value in attribute blocks */
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| 10 | #define EXT2_EXT_ATTR_MAGIC_v1 0xEA010000
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| 11 | #define EXT2_EXT_ATTR_MAGIC 0xEA020000
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| 12 |
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| 13 | /* Maximum number of references to one attribute block */
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| 14 | #define EXT2_EXT_ATTR_REFCOUNT_MAX 1024
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| 15 |
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| 16 | struct ext2_ext_attr_header {
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| 17 | __u32 h_magic; /* magic number for identification */
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| 18 | __u32 h_refcount; /* reference count */
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| 19 | __u32 h_blocks; /* number of disk blocks used */
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| 20 | __u32 h_hash; /* hash value of all attributes */
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| 21 | __u32 h_reserved[4]; /* zero right now */
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| 22 | };
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| 23 |
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| 24 | struct ext2_ext_attr_entry {
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| 25 | __u8 e_name_len; /* length of name */
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| 26 | __u8 e_name_index; /* attribute name index */
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| 27 | __u16 e_value_offs; /* offset in disk block of value */
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| 28 | __u32 e_value_block; /* disk block attribute is stored on (n/i) */
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| 29 | __u32 e_value_size; /* size of attribute value */
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| 30 | __u32 e_hash; /* hash value of name and value */
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| 31 | };
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| 32 |
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| 33 | #define EXT2_EXT_ATTR_PAD_BITS 2
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| 34 | #define EXT2_EXT_ATTR_PAD (1<<EXT2_EXT_ATTR_PAD_BITS)
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| 35 | #define EXT2_EXT_ATTR_ROUND (EXT2_EXT_ATTR_PAD-1)
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| 36 | #define EXT2_EXT_ATTR_LEN(name_len) \
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| 37 | (((name_len) + EXT2_EXT_ATTR_ROUND + \
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| 38 | sizeof(struct ext2_ext_attr_entry)) & ~EXT2_EXT_ATTR_ROUND)
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| 39 | #define EXT2_EXT_ATTR_NEXT(entry) \
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| 40 | ( (struct ext2_ext_attr_entry *)( \
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| 41 | (char *)(entry) + EXT2_EXT_ATTR_LEN((entry)->e_name_len)) )
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| 42 | #define EXT2_EXT_ATTR_SIZE(size) \
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| 43 | (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND)
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| 44 | #define EXT2_EXT_IS_LAST_ENTRY(entry) (*((__u32 *)(entry)) == 0UL)
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| 45 | #define EXT2_EXT_ATTR_NAME(entry) \
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| 46 | (((char *) (entry)) + sizeof(struct ext2_ext_attr_entry))
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| 47 | #define EXT2_XATTR_LEN(name_len) \
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| 48 | (((name_len) + EXT2_EXT_ATTR_ROUND + \
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| 49 | sizeof(struct ext2_xattr_entry)) & ~EXT2_EXT_ATTR_ROUND)
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| 50 | #define EXT2_XATTR_SIZE(size) \
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| 51 | (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND)
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| 52 |
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