From: Hans Holmberg <hans.holmberg@cnexlabs.com>
Date: Tue, 9 Oct 2018 13:11:50 +0200
Subject: [PATCH] lightnvm: pblk: fix write amplificiation calculation
Git-commit: 765462fa4c4d0fd3eb718f2ba14cb04c35219854
Patch-mainline: v4.20-rc1
References: bsc#1104967,FATE#325924
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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When the user data counter exceeds 32 bits, the write amplification
calculation does not provide the right value. Fix this by using
div64_u64 in stead of div64.
Fixes: 76758390f83e ("lightnvm: pblk: export write amplification counters to sysfs")
Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/lightnvm/pblk-sysfs.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c
index 9fc3dfa168b4..e56eeeeb914e 100644
--- a/drivers/lightnvm/pblk-sysfs.c
+++ b/drivers/lightnvm/pblk-sysfs.c
@@ -337,7 +337,6 @@ static ssize_t pblk_get_write_amp(u64 user, u64 gc, u64 pad,
{
int sz;
-
sz = snprintf(page, PAGE_SIZE,
"user:%lld gc:%lld pad:%lld WA:",
user, gc, pad);
@@ -349,7 +348,7 @@ static ssize_t pblk_get_write_amp(u64 user, u64 gc, u64 pad,
u32 wa_frac;
wa_int = (user + gc + pad) * 100000;
- wa_int = div_u64(wa_int, user);
+ wa_int = div64_u64(wa_int, user);
wa_int = div_u64_rem(wa_int, 100000, &wa_frac);
sz += snprintf(page + sz, PAGE_SIZE - sz, "%llu.%05u\n",
--
2.12.3