Josef Bacik
2010-Mar-05 21:59 UTC
[PATCH] Btrfs: make df be a little bit more understandable
The way we report df usage is way confusing for everybody, including some other
utilities (bacula for one). So this patch makes df a little bit more
understandable. First we make used actually count the total amount of used
space in all space info''s. This will give us a real view of how much
disk space
is in use. Second, for blocks available, only count data space. This makes
things like bacula work because it says 0 when you can no longer write anymore
data to the disk. I think this is a nice compromise, since you will end up with
something like the following
[root@alpha ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
148G 30G 111G 21% /
/dev/sda1 194M 116M 68M 64% /boot
tmpfs 985M 12K 985M 1% /dev/shm
/dev/mapper/VolGroup-LogVol02
145G 140G 0 100% /mnt/btrfs-test
Compare this with btrfsctl -i output
[root@alpha btrfs-progs-unstable]# ./btrfsctl -i /mnt/btrfs-test/
Metadata, DUP: total=4.62GB, used=2.46GB
System, DUP: total=8.00MB, used=24.00KB
Data: total=134.80GB, used=134.80GB
Metadata: total=8.00MB, used=0.00
System: total=4.00MB, used=0.00
operation complete
This way we show that there is no more data space to be used, but we have
another 5GB of space left for metadata. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
---
fs/btrfs/super.c | 29 ++++++++++++++++++++++++++---
1 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8a1ea6e..26681e3 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -623,14 +623,37 @@ static int btrfs_statfs(struct dentry *dentry, struct
kstatfs *buf)
{
struct btrfs_root *root = btrfs_sb(dentry->d_sb);
struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
+ struct list_head *head = &root->fs_info->space_info;
+ struct btrfs_space_info *found;
+ u64 total_used = 0;
+ u64 data_used = 0;
int bits = dentry->d_sb->s_blocksize_bits;
__be32 *fsid = (__be32 *)root->fs_info->fsid;
+ rcu_read_lock();
+ list_for_each_entry_rcu(found, head, list) {
+ if (found->flags & (BTRFS_BLOCK_GROUP_DUP|
+ BTRFS_BLOCK_GROUP_RAID10|
+ BTRFS_BLOCK_GROUP_RAID1)) {
+ total_used += found->bytes_used;
+ if (found->flags & BTRFS_BLOCK_GROUP_DATA)
+ data_used += found->bytes_used;
+ else
+ data_used += found->total_bytes;
+ }
+
+ total_used += found->bytes_used;
+ if (found->flags & BTRFS_BLOCK_GROUP_DATA)
+ data_used += found->bytes_used;
+ else
+ data_used += found->total_bytes;
+ }
+ rcu_read_unlock();
+
buf->f_namelen = BTRFS_NAME_LEN;
buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
- buf->f_bfree = buf->f_blocks -
- (btrfs_super_bytes_used(disk_super) >> bits);
- buf->f_bavail = buf->f_bfree;
+ buf->f_bfree = buf->f_blocks - (total_used >> bits);
+ buf->f_bavail = buf->f_blocks - (data_used >> bits);
buf->f_bsize = dentry->d_sb->s_blocksize;
buf->f_type = BTRFS_SUPER_MAGIC;
--
1.6.5.rc2
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