af01bda509
The "bdev" library provides basic primitives for file systems to talk to block device drivers, hiding the details of the underlying protocol and interaction model. This version of libbdev is rather basic. It is planned to support the following features in the long run: - asynchronous requests and replies; - recovery support for underlying block drivers; - retrying of failed I/O requests. The commit also changes our block-based file systems (mfs, ext2, isofs) to make use of libbdev.
182 lines
6.6 KiB
C
182 lines
6.6 KiB
C
#ifndef EXT2_CONST_H
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#define EXT2_CONST_H
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/* Tables sizes */
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#define NR_INODES 512 /* # slots in "in core" inode table;
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* should be more or less the same as
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* NR_VNODES in vfs
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*/
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#define GETDENTS_BUFSIZ 257
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#define INODE_HASH_LOG2 7 /* 2 based logarithm of the inode hash size */
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#define INODE_HASH_SIZE ((unsigned long)1<<INODE_HASH_LOG2)
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#define INODE_HASH_MASK (((unsigned long)1<<INODE_HASH_LOG2)-1)
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/* The type of sizeof may be (unsigned) long. Use the following macro for
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* taking the sizes of small objects so that there are no surprises like
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* (small) long constants being passed to routines expecting an int.
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*/
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#define usizeof(t) ((unsigned) sizeof(t))
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#define SUPER_MAGIC 0xEF53 /* magic number contained in super-block */
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#define EXT2_NAME_MAX 255
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/* Miscellaneous constants */
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#define SU_UID ((uid_t) 0) /* super_user's uid_t */
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#define NORMAL 0 /* forces get_block to do disk read */
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#define NO_READ 1 /* prevents get_block from doing disk read */
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#define PREFETCH 2 /* tells get_block not to read or mark dev */
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#define NO_BIT ((bit_t) 0) /* returned by alloc_bit() to signal failure */
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#define LOOK_UP 0 /* tells search_dir to lookup string */
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#define ENTER 1 /* tells search_dir to make dir entry */
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#define DELETE 2 /* tells search_dir to delete entry */
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#define IS_EMPTY 3 /* tells search_dir to ret. OK or ENOTEMPTY */
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/* write_map() args */
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#define WMAP_FREE (1 << 0)
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#define IGN_PERM 0
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#define CHK_PERM 1
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#define CLEAN 0 /* disk and memory copies identical */
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#define DIRTY 1 /* disk and memory copies differ */
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#define ATIME 002 /* set if atime field needs updating */
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#define CTIME 004 /* set if ctime field needs updating */
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#define MTIME 010 /* set if mtime field needs updating */
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#define BYTE_SWAP 0 /* tells conv2/conv4 to swap bytes */
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#define END_OF_FILE (-104) /* eof detected */
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#define SUPER_BLOCK_BYTES (1024) /* bytes offset */
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#define ROOT_INODE ((ino_t) 2) /* inode number for root directory */
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#define BOOT_BLOCK ((block_t) 0) /* block number of boot block */
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#define START_BLOCK ((block_t) 2) /* first block of FS (not counting SB) */
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#define BLOCK_ADDRESS_BYTES 4 /* bytes per address */
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#define SUPER_SIZE usizeof (struct super_block) /* sb size in RAM */
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#define SUPER_SIZE_D (1024) /* max size of superblock stored on disk */
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/* Directories related macroses */
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#define DIR_ENTRY_ALIGN 4
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/* ino + rec_len + name_len + file_type, doesn't include name and padding */
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#define MIN_DIR_ENTRY_SIZE 8
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#define DIR_ENTRY_CONTENTS_SIZE(d) (MIN_DIR_ENTRY_SIZE + (d)->d_name_len)
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/* size with padding */
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#define DIR_ENTRY_ACTUAL_SIZE(d) (DIR_ENTRY_CONTENTS_SIZE(d) + \
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((DIR_ENTRY_CONTENTS_SIZE(d) & 0x03) == 0 ? 0 : \
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DIR_ENTRY_ALIGN - (DIR_ENTRY_CONTENTS_SIZE(d) & 0x03) ))
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/* How many bytes can be taken from the end of dentry */
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#define DIR_ENTRY_SHRINK(d) (conv2(le_CPU, (d)->d_rec_len) \
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- DIR_ENTRY_ACTUAL_SIZE(d))
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/* Dentry can have padding, which can be used to enlarge namelen */
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#define DIR_ENTRY_MAX_NAME_LEN(d) (conv2(le_CPU, (d)->d_rec_len) \
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- MIN_DIR_ENTRY_SIZE)
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/* Constants relative to the data blocks */
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/* When change EXT2_NDIR_BLOCKS, modify ext2_max_size()!!!*/
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#define EXT2_NDIR_BLOCKS 12
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#define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
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#define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
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#define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
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#define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
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#define FS_BITMAP_CHUNKS(b) ((b)/usizeof (bitchunk_t))/* # map chunks/blk */
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#define FS_BITCHUNK_BITS (usizeof(bitchunk_t) * CHAR_BIT)
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#define FS_BITS_PER_BLOCK(b) (FS_BITMAP_CHUNKS(b) * FS_BITCHUNK_BITS)
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/* Inodes */
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/* Next 4 following macroses were taken from linux' ext2_fs.h */
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#define EXT2_GOOD_OLD_INODE_SIZE 128
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#define EXT2_GOOD_OLD_FIRST_INO 11
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#define EXT2_INODE_SIZE(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
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EXT2_GOOD_OLD_INODE_SIZE : \
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(s)->s_inode_size)
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#define EXT2_FIRST_INO(s) (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
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EXT2_GOOD_OLD_FIRST_INO : \
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(s)->s_first_ino)
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/* Maximum size of a fast symlink including trailing '\0' */
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#define MAX_FAST_SYMLINK_LENGTH \
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( sizeof(((d_inode *)0)->i_block[0]) * EXT2_N_BLOCKS )
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#define NUL(str,l,m) mfs_nul_f(__FILE__,__LINE__,(str), (l), (m))
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/* FS states */
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#define EXT2_VALID_FS 0x0001 /* Cleanly unmounted */
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#define EXT2_ERROR_FS 0x0002 /* Errors detected */
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#define EXT2_GOOD_OLD_REV 0 /* The good old (original) format */
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#define EXT2_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
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/* ext2 features, names shorted (cut EXT2_ prefix) */
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#define COMPAT_DIR_PREALLOC 0x0001
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#define COMPAT_IMAGIC_INODES 0x0002
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#define COMPAT_HAS_JOURNAL 0x0004
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#define COMPAT_EXT_ATTR 0x0008
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#define COMPAT_RESIZE_INO 0x0010
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#define COMPAT_DIR_INDEX 0x0020
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#define COMPAT_ANY 0xffffffff
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#define RO_COMPAT_SPARSE_SUPER 0x0001
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#define RO_COMPAT_LARGE_FILE 0x0002
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#define RO_COMPAT_BTREE_DIR 0x0004
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#define RO_COMPAT_ANY 0xffffffff
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#define INCOMPAT_COMPRESSION 0x0001
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#define INCOMPAT_FILETYPE 0x0002
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#define INCOMPAT_RECOVER 0x0004
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#define INCOMPAT_JOURNAL_DEV 0x0008
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#define INCOMPAT_META_BG 0x0010
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#define INCOMPAT_ANY 0xffffffff
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/* What do we support? */
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#define SUPPORTED_INCOMPAT_FEATURES (INCOMPAT_FILETYPE)
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#define SUPPORTED_RO_COMPAT_FEATURES (RO_COMPAT_SPARSE_SUPER | \
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RO_COMPAT_LARGE_FILE)
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/* Ext2 directory file types. Only the low 3 bits are used.
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* The other bits are reserved for now.
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*/
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#define EXT2_FT_UNKNOWN 0
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#define EXT2_FT_REG_FILE 1
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#define EXT2_FT_DIR 2
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#define EXT2_FT_CHRDEV 3
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#define EXT2_FT_BLKDEV 4
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#define EXT2_FT_FIFO 5
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#define EXT2_FT_SOCK 6
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#define EXT2_FT_SYMLINK 7
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#define EXT2_FT_MAX 8
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#define HAS_COMPAT_FEATURE(sp, mask) \
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( (sp)->s_feature_compat & (mask) )
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#define HAS_RO_COMPAT_FEATURE(sp, mask) \
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( (sp)->s_feature_ro_compat & (mask) )
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#define HAS_INCOMPAT_FEATURE(sp, mask) \
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( (sp)->s_feature_incompat & (mask) )
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/* hash-indexed directory */
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#define EXT2_INDEX_FL 0x00001000
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/* Top of directory hierarchies*/
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#define EXT2_TOPDIR_FL 0x00020000
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#define EXT2_PREALLOC_BLOCKS 8
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#endif /* EXT2_CONST_H */
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