From: Trond Myklebust Date: Thu, 18 Sep 2014 21:03:46 +0000 (-0400) Subject: pnfs/blocklayout: Fix a 64-bit division/remainder issue in bl_map_stripe X-Git-Tag: firefly_0821_release~176^2~3012^2~19 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5466112f0935f079e225514905c57d5e5285a9b6;p=firefly-linux-kernel-4.4.55.git 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' Fixes: 5c83746a0cf2 (pnfs/blocklayout: in-kernel GETDEVICEINFO XDR parsing) Cc: Stephen Rothwell Cc: Christoph Hellwig Reviewed-by: Christoph Hellwig Signed-off-by: Trond Myklebust --- diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c index 00f159da06ee..5aed4f98df41 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); @@ -165,7 +168,7 @@ static bool bl_map_stripe(struct pnfs_block_dev *dev, u64 offset, offset = chunk * dev->chunk_size; /* disk offset of the stripe */ - disk_offset = offset / dev->nr_children; + disk_offset = div_u64(offset, dev->nr_children); child = &dev->children[chunk_idx]; child->map(child, disk_offset, map);