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| author | Josef Bacik <josef@redhat.com> | 2011-08-20 08:29:51 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-08-21 07:02:00 -0700 |
| commit | 6719db6a23d4b7f1e5052eedae394135e3aef9c1 (patch) | |
| tree | 2faf96d69696df0edfc0ab4d8f0c980ee0b89986 /fs/btrfs | |
| parent | c063d8a60fc912ae198f054608ad461a69dc9a19 (diff) | |
| download | lwn-6719db6a23d4b7f1e5052eedae394135e3aef9c1.tar.gz lwn-6719db6a23d4b7f1e5052eedae394135e3aef9c1.zip | |
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 <josef@redhat.com>
Acked-and-tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 12 |
1 files 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); |