From 6719db6a23d4b7f1e5052eedae394135e3aef9c1 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Sat, 20 Aug 2011 08:29:51 -0400 Subject: [PATCH] Btrfs: fix 64 bit divide problem This fixes a regression introduced by commit cdcb725c05fe ("Btrfs: check if there is enough space for balancing smarter"). We can't do 64-bit divides on 32-bit architectures. In cases where we need to divide/multiply by 2 we should just left/right shift respectively, and in cases where theres N number of devices use do_div. Also make the counters u64 to match up with rw_devices. Thanks, Signed-off-by: Josef Bacik Acked-and-tested-by: Ingo Molnar Signed-off-by: Linus Torvalds --- fs/btrfs/extent-tree.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 80d6148f60ac..f5be06a2462f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -6735,9 +6735,9 @@ 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; + u64 dev_min = 1; + u64 dev_nr = 0; int index; - int dev_nr = 0; - int dev_min = 1; int full = 0; int ret = 0; @@ -6796,14 +6796,16 @@ 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; + /* Divide by 2 */ + min_free >>= 1; } else if (index == 1) { dev_min = 2; } else if (index == 2) { - min_free *= 2; + /* Multiply by 2 */ + min_free <<= 1; } else if (index == 3) { dev_min = fs_devices->rw_devices; - min_free /= dev_min; + do_div(min_free, dev_min); } mutex_lock(&root->fs_info->chunk_mutex); -- 2.39.2