Messages in this thread | | | Date | Sat, 20 Aug 2011 08:21:44 -0400 | From | Josef Bacik <> | Subject | Re: [PATCH v2] Btrfs: use do_div to avoid compile errors on 32bit box |
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On 08/19/2011 10:17 PM, Liu Bo wrote: > When doing div operation of u64 type, we need to be careful and use do_div > to avoid compile ERROR on 32bit box: > > "ERROR: "__udivdi3" [fs/btrfs/btrfs.ko] undefined! > make[1]: *** [__modpost] Error 1 > > v1->v2: > - fix stupid do_div() with type "signed integer". > > Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> > --- > fs/btrfs/extent-tree.c | 11 ++++++----- > 1 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 80d6148..e43e4f1 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -6735,9 +6735,10 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr) > struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; > struct btrfs_device *device; > u64 min_free; > + u32 dev_min = 1; > + u32 dev_nr = 0; > + u32 dup = 2; > int index; > - int dev_nr = 0; > - int dev_min = 1; > int full = 0; > int ret = 0; > > @@ -6796,14 +6797,14 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr) > index = get_block_group_index(block_group); > if (index == 0) { > dev_min = 4; > - min_free /= 2; > + do_div(min_free, dup);
I think Linus was less complaining about how you're dividing here and more about the fact that you are. A divide by 2 is the same as a >> 1. I'll send a patch to fix this. Thanks,
Josef
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