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-rw-r--r--fs/ext4/xattr.h227
1 files changed, 227 insertions, 0 deletions
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
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--- /dev/null
+++ b/fs/ext4/xattr.h
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ File: fs/ext4/xattr.h
+
+ On-disk format of extended attributes for the ext4 filesystem.
+
+ (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/xattr.h>
+
+/* Magic value in attribute blocks */
+#define EXT4_XATTR_MAGIC 0xEA020000
+
+/* Maximum number of references to one attribute block */
+#define EXT4_XATTR_REFCOUNT_MAX 1024
+
+/* Name indexes */
+#define EXT4_XATTR_INDEX_USER 1
+#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
+#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
+#define EXT4_XATTR_INDEX_TRUSTED 4
+#define EXT4_XATTR_INDEX_LUSTRE 5
+#define EXT4_XATTR_INDEX_SECURITY 6
+#define EXT4_XATTR_INDEX_SYSTEM 7
+#define EXT4_XATTR_INDEX_RICHACL 8
+#define EXT4_XATTR_INDEX_ENCRYPTION 9
+#define EXT4_XATTR_INDEX_HURD 10 /* Reserved for Hurd */
+
+struct ext4_xattr_header {
+ __le32 h_magic; /* magic number for identification */
+ __le32 h_refcount; /* reference count */
+ __le32 h_blocks; /* number of disk blocks used */
+ __le32 h_hash; /* hash value of all attributes */
+ __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */
+ /* id = inum if refcount=1, blknum otherwise */
+ __u32 h_reserved[3]; /* zero right now */
+};
+
+struct ext4_xattr_ibody_header {
+ __le32 h_magic; /* magic number for identification */
+};
+
+struct ext4_xattr_entry {
+ __u8 e_name_len; /* length of name */
+ __u8 e_name_index; /* attribute name index */
+ __le16 e_value_offs; /* offset in disk block of value */
+ __le32 e_value_inum; /* inode in which the value is stored */
+ __le32 e_value_size; /* size of attribute value */
+ __le32 e_hash; /* hash value of name and value */
+ char e_name[]; /* attribute name */
+};
+
+#define EXT4_XATTR_PAD_BITS 2
+#define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
+#define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
+#define EXT4_XATTR_LEN(name_len) \
+ (((name_len) + EXT4_XATTR_ROUND + \
+ sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
+#define EXT4_XATTR_NEXT(entry) \
+ ((struct ext4_xattr_entry *)( \
+ (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
+#define EXT4_XATTR_SIZE(size) \
+ (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
+
+#define IHDR(inode, raw_inode) \
+ ((struct ext4_xattr_ibody_header *) \
+ ((void *)raw_inode + \
+ EXT4_GOOD_OLD_INODE_SIZE + \
+ EXT4_I(inode)->i_extra_isize))
+#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
+
+/*
+ * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking
+ * for file system consistency errors, we use a somewhat bigger value.
+ * This allows XATTR_SIZE_MAX to grow in the future, but by using this
+ * instead of INT_MAX for certain consistency checks, we don't need to
+ * worry about arithmetic overflows. (Actually XATTR_SIZE_MAX is
+ * defined in include/uapi/linux/limits.h, so changing it is going
+ * not going to be trivial....)
+ */
+#define EXT4_XATTR_SIZE_MAX (1 << 24)
+
+/*
+ * The minimum size of EA value when you start storing it in an external inode
+ * size of block - size of header - size of 1 entry - 4 null bytes
+ */
+#define EXT4_XATTR_MIN_LARGE_EA_SIZE(b) \
+ ((b) - EXT4_XATTR_LEN(3) - sizeof(struct ext4_xattr_header) - 4)
+
+#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
+#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
+#define BFIRST(bh) ENTRY(BHDR(bh)+1)
+#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
+
+#define EXT4_ZERO_XATTR_VALUE ((void *)-1)
+
+/*
+ * If we want to add an xattr to the inode, we should make sure that
+ * i_extra_isize is not 0 and that the inode size is not less than
+ * EXT4_GOOD_OLD_INODE_SIZE + extra_isize + pad.
+ * EXT4_GOOD_OLD_INODE_SIZE extra_isize header entry pad data
+ * |--------------------------|------------|------|---------|---|-------|
+ */
+#define EXT4_INODE_HAS_XATTR_SPACE(inode) \
+ ((EXT4_I(inode)->i_extra_isize != 0) && \
+ (EXT4_GOOD_OLD_INODE_SIZE + EXT4_I(inode)->i_extra_isize + \
+ sizeof(struct ext4_xattr_ibody_header) + EXT4_XATTR_PAD <= \
+ EXT4_INODE_SIZE((inode)->i_sb)))
+
+struct ext4_xattr_info {
+ const char *name;
+ const void *value;
+ size_t value_len;
+ int name_index;
+ int in_inode;
+};
+
+struct ext4_xattr_search {
+ struct ext4_xattr_entry *first;
+ void *base;
+ void *end;
+ struct ext4_xattr_entry *here;
+ int not_found;
+};
+
+struct ext4_xattr_ibody_find {
+ struct ext4_xattr_search s;
+ struct ext4_iloc iloc;
+};
+
+struct ext4_xattr_inode_array {
+ unsigned int count; /* # of used items in the array */
+ struct inode *inodes[];
+};
+
+extern const struct xattr_handler ext4_xattr_user_handler;
+extern const struct xattr_handler ext4_xattr_trusted_handler;
+extern const struct xattr_handler ext4_xattr_security_handler;
+extern const struct xattr_handler ext4_xattr_hurd_handler;
+
+#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
+
+/*
+ * The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes.
+ * The first is to signal that there the inline xattrs and data are
+ * taking up so much space that we might as well not keep trying to
+ * expand it. The second is that xattr_sem is taken for writing, so
+ * we shouldn't try to recurse into the inode expansion. For this
+ * second case, we need to make sure that we take save and restore the
+ * NO_EXPAND state flag appropriately.
+ */
+static inline void ext4_write_lock_xattr(struct inode *inode, int *save)
+{
+ down_write(&EXT4_I(inode)->xattr_sem);
+ *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
+ ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
+}
+
+static inline int ext4_write_trylock_xattr(struct inode *inode, int *save)
+{
+ if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0)
+ return 0;
+ *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
+ ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
+ return 1;
+}
+
+static inline void ext4_write_unlock_xattr(struct inode *inode, int *save)
+{
+ if (*save == 0)
+ ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
+ up_write(&EXT4_I(inode)->xattr_sem);
+}
+
+extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
+
+extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
+extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
+extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
+extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
+ bool is_create, int *credits);
+extern int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
+ struct buffer_head *block_bh, size_t value_len,
+ bool is_create);
+
+extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
+ struct ext4_xattr_inode_array **array,
+ int extra_credits);
+extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array);
+
+extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+ struct ext4_inode *raw_inode, handle_t *handle);
+extern void ext4_evict_ea_inode(struct inode *inode);
+
+extern const struct xattr_handler *ext4_xattr_handlers[];
+
+extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
+ struct ext4_xattr_ibody_find *is);
+extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
+ const char *name,
+ void *buffer, size_t buffer_size);
+extern int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
+ struct ext4_xattr_info *i,
+ struct ext4_xattr_ibody_find *is);
+
+extern struct mb_cache *ext4_xattr_create_cache(void);
+extern void ext4_xattr_destroy_cache(struct mb_cache *);
+
+#ifdef CONFIG_EXT4_FS_SECURITY
+extern int ext4_init_security(handle_t *handle, struct inode *inode,
+ struct inode *dir, const struct qstr *qstr);
+#else
+static inline int ext4_init_security(handle_t *handle, struct inode *inode,
+ struct inode *dir, const struct qstr *qstr)
+{
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_LOCKDEP
+extern void ext4_xattr_inode_set_class(struct inode *ea_inode);
+#else
+static inline void ext4_xattr_inode_set_class(struct inode *ea_inode) { }
+#endif
+
+extern int ext4_get_inode_usage(struct inode *inode, qsize_t *usage);