diff options
Diffstat (limited to 'ext2fs')
| -rw-r--r-- | ext2fs/ext2fs.h | 64 |
1 files changed, 23 insertions, 41 deletions
diff --git a/ext2fs/ext2fs.h b/ext2fs/ext2fs.h index 7517d9a8..8e73ae0a 100644 --- a/ext2fs/ext2fs.h +++ b/ext2fs/ext2fs.h @@ -109,11 +109,15 @@ void pokel_inherit (struct pokel *pokel, struct pokel *from); /* ---------------------------------------------------------------- */ /* Bitmap routines. */ +#include <stdint.h> + /* Returns TRUE if bit NUM is set in BITMAP. */ EXT2FS_EI int test_bit (unsigned num, char *bitmap) { - return bitmap[num >> 3] & (1 << (num & 0x7)); + const uint32_t *const bw = (uint32_t *) bitmap + (num >> 5); + const uint_fast32_t mask = 1 << (num & 31); + return *bw & mask; } /* Sets bit NUM in BITMAP, and returns the previous state of the bit. Unlike @@ -121,17 +125,9 @@ test_bit (unsigned num, char *bitmap) EXT2FS_EI int set_bit (unsigned num, char *bitmap) { - char *p = bitmap + (num >> 3); - char byte = *p; - char mask = (1 << (num & 0x7)); - - if (byte & mask) - return 1; - else - { - *p = byte | mask; - return 0; - } + uint32_t *const bw = (uint32_t *) bitmap + (num >> 5); + const uint_fast32_t mask = 1 << (num & 31); + return (*bw & mask) ?: (*bw |= mask, 0); } /* Clears bit NUM in BITMAP, and returns the previous state of the bit. @@ -139,17 +135,9 @@ set_bit (unsigned num, char *bitmap) EXT2FS_EI int clear_bit (unsigned num, char *bitmap) { - char *p = bitmap + (num >> 3); - char byte = *p; - char mask = (1 << (num & 0x7)); - - if (byte & mask) - { - *p = byte & ~mask; - return 1; - } - else - return 0; + uint32_t *const bw = (uint32_t *) bitmap + (num >> 5); + const uint_fast32_t mask = 1 << (num & 31); + return (*bw & mask) ? (*bw &= ~mask, mask) : 0; } /* ---------------------------------------------------------------- */ @@ -224,24 +212,24 @@ extern struct store_parsed *store_parsed; /* Mapped image of the disk. */ extern void *disk_image; -/* Our in-core copy of the super-block. */ +/* Our in-core copy of the super-block (pointer into the disk_image). */ struct ext2_super_block *sblock; /* True if sblock has been modified. */ int sblock_dirty; /* Where the super-block is located on disk (at min-block 1). */ -#define SBLOCK_BLOCK 1 -#define SBLOCK_OFFS (SBLOCK_BLOCK * EXT2_MIN_BLOCK_SIZE) -#define SBLOCK_SIZE (sizeof (struct ext2_super_block)) -#define SBLOCK_LBLOCK (SBLOCK_BLOCK >> BLOCKSIZE_SCALE) +#define SBLOCK_BLOCK 1 /* Default location, second 1k block. */ +#define SBLOCK_SIZE (sizeof (struct ext2_super_block)) +extern unsigned int sblock_block; /* Specified location (in 1k blocks). */ +#define SBLOCK_OFFS (sblock_block << 10) /* Byte offset of superblock. */ /* The filesystem block-size. */ -unsigned long block_size; +unsigned int block_size; /* The log base 2 of BLOCK_SIZE. */ -unsigned log2_block_size; +unsigned int log2_block_size; /* The number of bits to scale min-blocks to get filesystem blocks. */ -#define BLOCKSIZE_SCALE (log2_block_size - EXT2_MIN_BLOCK_LOG_SIZE) +#define BLOCKSIZE_SCALE (sblock->s_log_block_size) /* log2 of the number of device blocks in a filesystem block. */ unsigned log2_dev_blocks_per_fs_block; @@ -299,16 +287,10 @@ unsigned long next_generation; #define bptr_block(ptr) boffs_block(bptr_offs(ptr)) /* Get the descriptor for block group NUM. The block group descriptors are - stored starting in the filesystem block following the super block. */ -EXT2FS_EI struct ext2_group_desc * -group_desc(unsigned long num) -{ - int desc_per_block = EXT2_DESC_PER_BLOCK(sblock); - unsigned long group_desc = num / desc_per_block; - unsigned long desc = num % desc_per_block; - return ((struct ext2_group_desc *) bptr(SBLOCK_LBLOCK + 1 + group_desc) - + desc); -} + stored starting in the filesystem block following the super block. + We cache a pointer into the disk image for easy lookup. */ +#define group_desc(num) (&group_desc_image[num]) +struct ext2_group_desc *group_desc_image; #define inode_group_num(inum) (((inum) - 1) / sblock->s_inodes_per_group) |