[0/2] Provide an estimation of (free/total) inodes in statfs

Message

Johannes Thumshirn Oct. 24, 2019, 3:44 p.m. UTC

There is a user report on the BeeGFS mailing list, that it's impossible to run
BeeGFS on top of BTRFS.

This is because BeeGFS is storing it's meta-data either in the underlying
file-systems extended attributes or directly in an inode if it can make use of
inline inodes.

A more detailed description is in patch 2/2.

Without the patch applied:
rapido1:/# df -hTi /mnt/test
Filesystem     Type     Inodes IUsed IFree IUse% Mounted on
/mnt/test      btrfs         0     0     0     - /mnt/test

With the patch applied on an empty fs:
rapido1:/# df -hTi /mnt/test
Filesystem     Type     Inodes IUsed IFree IUse% Mounted on
/dev/zram0     btrfs      1.6K     0  1.6K    0% /mnt/test

With the patch applied on a dirty fs:
rapido1:/# df -hTi /mnt/test
Filesystem     Type     Inodes IUsed IFree IUse% Mounted on
/dev/zram0     btrfs      1.6K  1.5K   197   88% /mnt/test

Johannes Thumshirn (2):
  btrfs: remove cached space_info in btrfs_statfs()
  btrfs: provide an estimated number of inodes for statfs

 fs/btrfs/super.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)