2014-09-18 21:09:56

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH] pnfs/blocklayout: Fix a 64-bit division/remainder issue in bl_map_stripe

kbuild test robot reports:

fs/built-in.o: In function `bl_map_stripe':
>> :(.text+0x965b4): undefined reference to `__aeabi_uldivmod'
>> :(.text+0x965cc): undefined reference to `__aeabi_uldivmod'
>> :(.text+0x96604): undefined reference to `__aeabi_uldivmod'

Cc: Stephen Rothwell <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/blocklayout/dev.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c
index 00f159da06ee..ffe23b0d8a31 100644
--- a/fs/nfs/blocklayout/dev.c
+++ b/fs/nfs/blocklayout/dev.c
@@ -150,10 +150,13 @@ static bool bl_map_stripe(struct pnfs_block_dev *dev, u64 offset,
struct pnfs_block_dev_map *map)
{
struct pnfs_block_dev *child;
- u64 chunk = (offset / dev->chunk_size);
- int chunk_idx = chunk % dev->nr_children;
+ u64 chunk;
+ u32 chunk_idx;
u64 disk_offset;

+ chunk = div_u64(offset, dev->chunk_size);
+ div_u64_rem(chunk, dev->nr_children, &chunk_idx);
+
if (chunk_idx > dev->nr_children) {
dprintk("%s: invalid chunk idx %d (%lld/%lld)\n",
__func__, chunk_idx, offset, dev->chunk_size);
--
1.9.3