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213 lines
7.2 KiB
213 lines
7.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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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, <[email protected]> |
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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_inum; /* inode in which the value is stored */ |
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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[]; /* 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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/* |
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* XATTR_SIZE_MAX is currently 64k, but for the purposes of checking |
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* for file system consistency errors, we use a somewhat bigger value. |
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* This allows XATTR_SIZE_MAX to grow in the future, but by using this |
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* instead of INT_MAX for certain consistency checks, we don't need to |
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* worry about arithmetic overflows. (Actually XATTR_SIZE_MAX is |
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* defined in include/uapi/linux/limits.h, so changing it is going |
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* not going to be trivial....) |
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*/ |
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#define EXT4_XATTR_SIZE_MAX (1 << 24) |
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/* |
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* The minimum size of EA value when you start storing it in an external inode |
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* size of block - size of header - size of 1 entry - 4 null bytes |
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*/ |
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#define EXT4_XATTR_MIN_LARGE_EA_SIZE(b) \ |
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((b) - EXT4_XATTR_LEN(3) - sizeof(struct ext4_xattr_header) - 4) |
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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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const char *name; |
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const void *value; |
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size_t value_len; |
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int name_index; |
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int in_inode; |
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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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struct ext4_xattr_inode_array { |
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unsigned int count; /* # of used items in the array */ |
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struct inode *inodes[]; |
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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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extern const struct xattr_handler ext4_xattr_hurd_handler; |
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#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c" |
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/* |
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* The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes. |
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* The first is to signal that there the inline xattrs and data are |
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* taking up so much space that we might as well not keep trying to |
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* expand it. The second is that xattr_sem is taken for writing, so |
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* we shouldn't try to recurse into the inode expansion. For this |
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* second case, we need to make sure that we take save and restore the |
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* NO_EXPAND state flag appropriately. |
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*/ |
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static inline void ext4_write_lock_xattr(struct inode *inode, int *save) |
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{ |
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down_write(&EXT4_I(inode)->xattr_sem); |
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*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); |
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ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); |
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} |
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static inline int ext4_write_trylock_xattr(struct inode *inode, int *save) |
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{ |
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if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0) |
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return 0; |
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*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); |
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ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); |
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return 1; |
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} |
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static inline void ext4_write_unlock_xattr(struct inode *inode, int *save) |
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{ |
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if (*save == 0) |
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ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND); |
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up_write(&EXT4_I(inode)->xattr_sem); |
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} |
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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 int ext4_xattr_set_credits(struct inode *inode, size_t value_len, |
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bool is_create, int *credits); |
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extern int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, |
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struct buffer_head *block_bh, size_t value_len, |
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bool is_create); |
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extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, |
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struct ext4_xattr_inode_array **array, |
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int extra_credits); |
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extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array); |
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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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#ifdef CONFIG_LOCKDEP |
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extern void ext4_xattr_inode_set_class(struct inode *ea_inode); |
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#else |
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static inline void ext4_xattr_inode_set_class(struct inode *ea_inode) { } |
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#endif |
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extern int ext4_get_inode_usage(struct inode *inode, qsize_t *usage);
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