Thread (26 messages) 26 messages, 3 authors, 2018-03-22

Re: [for-4.17 20/20] bcache: Fix a compiler warning in bcache_device_init()

From: Coly Li <hidden>
Date: 2018-03-19 01:32:58

On 19/03/2018 8:36 AM, Michael Lyle wrote:
From: Bart Van Assche <redacted>

Avoid that building with W=1 triggers the following compiler warning:

drivers/md/bcache/super.c:776:20: warning: comparison is always false due to limited range of data type [-Wtype-limits]
      d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) {
                    ^

Signed-off-by: Bart Van Assche <redacted>
Reviewed-by: Michael Lyle <redacted>
There is a missing Reviewed-by: Coly Li [off-list ref] from me :-)

Thanks.

Coly Li
quoted hunk ↗ jump to hunk
---
 drivers/md/bcache/super.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 640ff8072ed8..d90d9e59ca00 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -778,6 +778,8 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
 			      sector_t sectors)
 {
 	struct request_queue *q;
+	const size_t max_stripes = min_t(size_t, INT_MAX,
+					 SIZE_MAX / sizeof(atomic_t));
 	size_t n;
 	int idx;
 
@@ -786,9 +788,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
 
 	d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size);
 
-	if (!d->nr_stripes ||
-	    d->nr_stripes > INT_MAX ||
-	    d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) {
+	if (!d->nr_stripes || d->nr_stripes > max_stripes) {
 		pr_err("nr_stripes too large or invalid: %u (start sector beyond end of disk?)",
 			(unsigned)d->nr_stripes);
 		return -ENOMEM;
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