1 extern void abort (void);
2
3 typedef struct foo_t
4 {
5 unsigned int blksz;
6 unsigned int bf_cnt;
7 } foo_t;
8
9 #define _RNDUP(x, unit) ((((x) + (unit) - 1) / (unit)) * (unit))
10 #define _RNDDOWN(x, unit) ((x) - ((x)%(unit)))
11
12 long long
foo(foo_t * const pxp,long long offset,unsigned int extent)13 foo (foo_t *const pxp, long long offset, unsigned int extent)
14 {
15 long long blkoffset = _RNDDOWN(offset, (long long )pxp->blksz);
16 unsigned int diff = (unsigned int)(offset - blkoffset);
17 unsigned int blkextent = _RNDUP(diff + extent, pxp->blksz);
18
19 if (pxp->blksz < blkextent)
20 return -1LL;
21
22 if (pxp->bf_cnt > pxp->blksz)
23 pxp->bf_cnt = pxp->blksz;
24
25 return blkoffset;
26 }
27
28 int
main()29 main ()
30 {
31 foo_t x;
32 long long xx;
33
34 x.blksz = 8192;
35 x.bf_cnt = 0;
36 xx = foo (&x, 0, 4096);
37 if (xx != 0LL)
38 abort ();
39 return 0;
40 }
41