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pnfs/blocklayout: Fix a 64-bit division/remainder issue in bl_map_stripe

Message ID 1411074591-73466-1-git-send-email-trond.myklebust@primarydata.com (mailing list archive)
State New, archived
Headers show

Commit Message

Trond Myklebust Sept. 18, 2014, 9:09 p.m. UTC 
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 <sfr@canb.auug.org.au>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
 fs/nfs/blocklayout/dev.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
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Patch

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);