fs/ext4/xattr.h

   1 /*
   2   File: fs/ext4/xattr.h
   3
   4   On-disk format of extended attributes for the ext4 filesystem.
   5
   6   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   7 */
   8
   9 #include <linux/xattr.h>
  10
  11 /* Magic value in attribute blocks */
  12 #define EXT4_XATTR_MAGIC                0xEA020000
  13
  14 /* Maximum number of references to one attribute block */
  15 #define EXT4_XATTR_REFCOUNT_MAX         1024
  16
  17 /* Name indexes */
  18 #define EXT4_XATTR_INDEX_USER                   1
  19 #define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS       2
  20 #define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT      3
  21 #define EXT4_XATTR_INDEX_TRUSTED                4
  22 #define EXT4_XATTR_INDEX_LUSTRE                 5
  23 #define EXT4_XATTR_INDEX_SECURITY               6
  24 #define EXT4_XATTR_INDEX_SYSTEM                 7
  25
  26 struct ext4_xattr_header {
  27         __le32  h_magic;        /* magic number for identification */
  28         __le32  h_refcount;     /* reference count */
  29         __le32  h_blocks;       /* number of disk blocks used */
  30         __le32  h_hash;         /* hash value of all attributes */
  31         __le32  h_checksum;     /* crc32c(uuid+id+xattrblock) */
  32                                 /* id = inum if refcount=1, blknum otherwise */
  33         __u32   h_reserved[3];  /* zero right now */
  34 };
  35
  36 struct ext4_xattr_ibody_header {
  37         __le32  h_magic;        /* magic number for identification */
  38 };
  39
  40 struct ext4_xattr_entry {
  41         __u8    e_name_len;     /* length of name */
  42         __u8    e_name_index;   /* attribute name index */
  43         __le16  e_value_offs;   /* offset in disk block of value */
  44         __le32  e_value_block;  /* disk block attribute is stored on (n/i) */
  45         __le32  e_value_size;   /* size of attribute value */
  46         __le32  e_hash;         /* hash value of name and value */
  47         char    e_name[0];      /* attribute name */
  48 };
  49
  50 #define EXT4_XATTR_PAD_BITS             2
  51 #define EXT4_XATTR_PAD          (1<<EXT4_XATTR_PAD_BITS)
  52 #define EXT4_XATTR_ROUND                (EXT4_XATTR_PAD-1)
  53 #define EXT4_XATTR_LEN(name_len) \
  54         (((name_len) + EXT4_XATTR_ROUND + \
  55         sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
  56 #define EXT4_XATTR_NEXT(entry) \
  57         ((struct ext4_xattr_entry *)( \
  58          (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
  59 #define EXT4_XATTR_SIZE(size) \
  60         (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
  61
  62 #define IHDR(inode, raw_inode) \
  63         ((struct ext4_xattr_ibody_header *) \
  64                 ((void *)raw_inode + \
  65                 EXT4_GOOD_OLD_INODE_SIZE + \
  66                 EXT4_I(inode)->i_extra_isize))
  67 #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
  68
  69 #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
  70 #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
  71 #define BFIRST(bh) ENTRY(BHDR(bh)+1)
  72 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
  73
  74
  75 struct ext4_xattr_info {
  76         int name_index;
  77         const char *name;
  78         const void *value;
  79         size_t value_len;
  80 };
  81
  82 struct ext4_xattr_search {
  83         struct ext4_xattr_entry *first;
  84         void *base;
  85         void *end;
  86         struct ext4_xattr_entry *here;
  87         int not_found;
  88 };
  89
  90 struct ext4_xattr_ibody_find {
  91         struct ext4_xattr_search s;
  92         struct ext4_iloc iloc;
  93 };
  94
  95 extern const struct xattr_handler ext4_xattr_user_handler;
  96 extern const struct xattr_handler ext4_xattr_trusted_handler;
  97 extern const struct xattr_handler ext4_xattr_acl_access_handler;
  98 extern const struct xattr_handler ext4_xattr_acl_default_handler;
  99 extern const struct xattr_handler ext4_xattr_security_handler;
 100
 101 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
 102
 103 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
 104 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
 105 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
 106
 107 extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
 108 extern void ext4_xattr_put_super(struct super_block *);
 109
 110 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
 111                             struct ext4_inode *raw_inode, handle_t *handle);
 112
 113 extern int __init ext4_init_xattr(void);
 114 extern void ext4_exit_xattr(void);
 115
 116 extern const struct xattr_handler *ext4_xattr_handlers[];
 117
 118 extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
 119                                  struct ext4_xattr_ibody_find *is);
 120 extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
 121                                 const char *name,
 122                                 void *buffer, size_t buffer_size);
 123 extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
 124                                        struct ext4_xattr_info *i,
 125                                        struct ext4_xattr_ibody_find *is);
 126
 127 extern int ext4_has_inline_data(struct inode *inode);
 128 extern int ext4_get_inline_size(struct inode *inode);
 129 extern int ext4_get_max_inline_size(struct inode *inode);
 130 extern int ext4_find_inline_data_nolock(struct inode *inode);
 131 extern void ext4_write_inline_data(struct inode *inode,
 132                                    struct ext4_iloc *iloc,
 133                                    void *buffer, loff_t pos,
 134                                    unsigned int len);
 135 extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
 136                                     unsigned int len);
 137 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
 138                                  unsigned int len);
 139 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
 140
 141 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
 142 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
 143                                          struct inode *inode,
 144                                          loff_t pos, unsigned len,
 145                                          unsigned flags,
 146                                          struct page **pagep);
 147 extern int ext4_write_inline_data_end(struct inode *inode,
 148                                       loff_t pos, unsigned len,
 149                                       unsigned copied,
 150                                       struct page *page);
 151 extern struct buffer_head *
 152 ext4_journalled_write_inline_data(struct inode *inode,
 153                                   unsigned len,
 154                                   struct page *page);
 155 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
 156                                            struct inode *inode,
 157                                            loff_t pos, unsigned len,
 158                                            unsigned flags,
 159                                            struct page **pagep,
 160                                            void **fsdata);
 161 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
 162                                          unsigned len, unsigned copied,
 163                                          struct page *page);
 164 extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
 165                                      struct inode *inode);
 166 extern int ext4_try_create_inline_dir(handle_t *handle,
 167                                       struct inode *parent,
 168                                       struct inode *inode);
 169 extern int ext4_read_inline_dir(struct file *filp,
 170                                 void *dirent, filldir_t filldir,
 171                                 int *has_inline_data);
 172 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
 173                                         const struct qstr *d_name,
 174                                         struct ext4_dir_entry_2 **res_dir,
 175                                         int *has_inline_data);
 176 extern int ext4_delete_inline_entry(handle_t *handle,
 177                                     struct inode *dir,
 178                                     struct ext4_dir_entry_2 *de_del,
 179                                     struct buffer_head *bh,
 180                                     int *has_inline_data);
 181 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
 182 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
 183                                         struct ext4_dir_entry_2 **parent_de,
 184                                         int *retval);
 185 extern int ext4_inline_data_fiemap(struct inode *inode,
 186                                    struct fiemap_extent_info *fieinfo,
 187                                    int *has_inline);
 188 extern int ext4_try_to_evict_inline_data(handle_t *handle,
 189                                          struct inode *inode,
 190                                          int needed);
 191 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
 192
 193 extern int ext4_convert_inline_data(struct inode *inode);
 194
 195 #ifdef CONFIG_EXT4_FS_SECURITY
 196 extern int ext4_init_security(handle_t *handle, struct inode *inode,
 197                               struct inode *dir, const struct qstr *qstr);
 198 #else
 199 static inline int ext4_init_security(handle_t *handle, struct inode *inode,
 200                                      struct inode *dir, const struct qstr *qstr)
 201 {
 202         return 0;
 203 }
 204 #endif