ref: 733c5d6645b133b60d304c38fcb1398f94d0618c
dir: /sys/src/cmd/ext4srv/ext4_bitmap.c/
#include "ext4_config.h" #include "ext4_types.h" #include "ext4_misc.h" #include "ext4_debug.h" #include "ext4_bitmap.h" void ext4_bmap_bits_free(u8int *bmap, u32int sbit, u32int bcnt) { u32int i = sbit; while(i & 7){ if(bcnt-- == 0) return; ext4_bmap_bit_clr(bmap, i++); } sbit = i; bmap += sbit >> 3; memset(bmap, 0, bcnt >> 3); bmap += bcnt >> 3; bcnt &= 7; while(bcnt > 0) ext4_bmap_bit_clr(bmap, --bcnt); } int ext4_bmap_bit_find_clr(u8int *bmap, u32int sbit, u32int ebit, u32int *bit_id, bool *no_space) { u32int i; u32int bcnt = ebit - sbit; i = sbit; *no_space = false; while (i & 7) { if(!bcnt){ Nospace: *no_space = true; return -1; } if (ext4_bmap_is_bit_clr(bmap, i)) { *bit_id = sbit; return 0; } i++; bcnt--; } sbit = i; bmap += (sbit >> 3); while (bcnt >= 8) { if (*bmap != 0xFF) { for (i = 0; i < 8; ++i) { if (ext4_bmap_is_bit_clr(bmap, i)) { *bit_id = sbit + i; return 0; } } } bmap += 1; bcnt -= 8; sbit += 8; } for (i = 0; i < bcnt; ++i) { if (ext4_bmap_is_bit_clr(bmap, i)) { *bit_id = sbit + i; return 0; } } goto Nospace; }