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bcache: fix a spurious gcc complaint, use scnprintf 

An old version of gcc was complaining about using a const int as the
size of a stack allocated array. Which should be fine - but using
ARRAY_SIZE() is better, anyways.

Also, refactor the code to use scnprintf().

Signed-off-by: Kent Overstreet <koverstreet@google.com>
This commit is contained in:
Kent Overstreet 2013-05-28 21:53:19 -07:00
parent 5c694129c8
commit bbc77aa7fb
1 changed files with 20 additions and 19 deletions
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39
drivers/md/bcache/sysfs.c
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@ -665,12 +665,10 @@ SHOW(__bch_cache)
int cmp(const void *l, const void *r)
{ return *((uint16_t *) r) - *((uint16_t *) l); }
/* Number of quantiles we compute */
const unsigned nq = 31;
size_t n = ca->sb.nbuckets, i, unused, btree;
uint64_t sum = 0;
uint16_t q[nq], *p, *cached;
/* Compute 31 quantiles */
uint16_t q[31], *p, *cached;
ssize_t ret;
cached = p = vmalloc(ca->sb.nbuckets * sizeof(uint16_t));
@ -703,26 +701,29 @@ SHOW(__bch_cache)
if (n)
do_div(sum, n);
for (i = 0; i < nq; i++)
q[i] = INITIAL_PRIO - cached[n * (i + 1) / (nq + 1)];
for (i = 0; i < ARRAY_SIZE(q); i++)
q[i] = INITIAL_PRIO - cached[n * (i + 1) /
(ARRAY_SIZE(q) + 1)];
vfree(p);
ret = snprintf(buf, PAGE_SIZE,
"Unused: %zu%%\n"
"Metadata: %zu%%\n"
"Average: %llu\n"
"Sectors per Q: %zu\n"
"Quantiles: [",
unused * 100 / (size_t) ca->sb.nbuckets,
btree * 100 / (size_t) ca->sb.nbuckets, sum,
n * ca->sb.bucket_size / (nq + 1));
ret = scnprintf(buf, PAGE_SIZE,
"Unused: %zu%%\n"
"Metadata: %zu%%\n"
"Average: %llu\n"
"Sectors per Q: %zu\n"
"Quantiles: [",
unused * 100 / (size_t) ca->sb.nbuckets,
btree * 100 / (size_t) ca->sb.nbuckets, sum,
n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
for (i = 0; i < nq && ret < (ssize_t) PAGE_SIZE; i++)
ret += snprintf(buf + ret, PAGE_SIZE - ret,
i < nq - 1 ? "%u " : "%u]\n", q[i]);
for (i = 0; i < ARRAY_SIZE(q); i++)
ret += scnprintf(buf + ret, PAGE_SIZE - ret,
"%u ", q[i]);
ret--;
ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");
buf[PAGE_SIZE - 1] = '\0';
return ret;
}