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The Hurd is using inode fields which restricts it from using more
advanced ext4 file system features, due to design choices made over a
decade ago. By giving the Hurd an extended attribute index field we
allow it to move the translator and author fields out of the core
inode fields, and hopefully we can get rid of ugly hacks such as
EXT4_OS_HURD and EXT4_MOUNT2_HURD_COMPAT somday.
For more information please see:
https://summerofcode.withgoogle.com/projects/#5869799859027968
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
140 lines
4.5 KiB
C
140 lines
4.5 KiB
C
/*
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File: fs/ext4/xattr.h
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On-disk format of extended attributes for the ext4 filesystem.
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(C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
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*/
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#include <linux/xattr.h>
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/* Magic value in attribute blocks */
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#define EXT4_XATTR_MAGIC 0xEA020000
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/* Maximum number of references to one attribute block */
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#define EXT4_XATTR_REFCOUNT_MAX 1024
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/* Name indexes */
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#define EXT4_XATTR_INDEX_USER 1
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#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
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#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
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#define EXT4_XATTR_INDEX_TRUSTED 4
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#define EXT4_XATTR_INDEX_LUSTRE 5
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#define EXT4_XATTR_INDEX_SECURITY 6
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#define EXT4_XATTR_INDEX_SYSTEM 7
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#define EXT4_XATTR_INDEX_RICHACL 8
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#define EXT4_XATTR_INDEX_ENCRYPTION 9
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#define EXT4_XATTR_INDEX_HURD 10 /* Reserved for Hurd */
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struct ext4_xattr_header {
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__le32 h_magic; /* magic number for identification */
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__le32 h_refcount; /* reference count */
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__le32 h_blocks; /* number of disk blocks used */
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__le32 h_hash; /* hash value of all attributes */
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__le32 h_checksum; /* crc32c(uuid+id+xattrblock) */
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/* id = inum if refcount=1, blknum otherwise */
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__u32 h_reserved[3]; /* zero right now */
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};
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struct ext4_xattr_ibody_header {
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__le32 h_magic; /* magic number for identification */
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};
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struct ext4_xattr_entry {
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__u8 e_name_len; /* length of name */
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__u8 e_name_index; /* attribute name index */
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__le16 e_value_offs; /* offset in disk block of value */
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__le32 e_value_block; /* disk block attribute is stored on (n/i) */
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__le32 e_value_size; /* size of attribute value */
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__le32 e_hash; /* hash value of name and value */
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char e_name[0]; /* attribute name */
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};
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#define EXT4_XATTR_PAD_BITS 2
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#define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
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#define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
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#define EXT4_XATTR_LEN(name_len) \
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(((name_len) + EXT4_XATTR_ROUND + \
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sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
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#define EXT4_XATTR_NEXT(entry) \
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((struct ext4_xattr_entry *)( \
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(char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
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#define EXT4_XATTR_SIZE(size) \
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(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
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#define IHDR(inode, raw_inode) \
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((struct ext4_xattr_ibody_header *) \
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((void *)raw_inode + \
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EXT4_GOOD_OLD_INODE_SIZE + \
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EXT4_I(inode)->i_extra_isize))
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#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
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#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
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#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
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#define BFIRST(bh) ENTRY(BHDR(bh)+1)
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#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
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#define EXT4_ZERO_XATTR_VALUE ((void *)-1)
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struct ext4_xattr_info {
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int name_index;
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const char *name;
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const void *value;
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size_t value_len;
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};
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struct ext4_xattr_search {
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struct ext4_xattr_entry *first;
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void *base;
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void *end;
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struct ext4_xattr_entry *here;
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int not_found;
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};
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struct ext4_xattr_ibody_find {
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struct ext4_xattr_search s;
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struct ext4_iloc iloc;
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};
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extern const struct xattr_handler ext4_xattr_user_handler;
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extern const struct xattr_handler ext4_xattr_trusted_handler;
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extern const struct xattr_handler ext4_xattr_security_handler;
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#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
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extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
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extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
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extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
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extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
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extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
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extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
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struct ext4_inode *raw_inode, handle_t *handle);
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extern const struct xattr_handler *ext4_xattr_handlers[];
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extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
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struct ext4_xattr_ibody_find *is);
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extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
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const char *name,
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void *buffer, size_t buffer_size);
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extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
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struct ext4_xattr_info *i,
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struct ext4_xattr_ibody_find *is);
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extern struct mb_cache *ext4_xattr_create_cache(void);
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extern void ext4_xattr_destroy_cache(struct mb_cache *);
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#ifdef CONFIG_EXT4_FS_SECURITY
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extern int ext4_init_security(handle_t *handle, struct inode *inode,
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struct inode *dir, const struct qstr *qstr);
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#else
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static inline int ext4_init_security(handle_t *handle, struct inode *inode,
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struct inode *dir, const struct qstr *qstr)
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{
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return 0;
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}
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#endif
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