tree bcdc9176cd2c5ef3760846c28b21dd900c14b744
parent 4b9d7b59bfcb62a7d438876eac5a054db32904dd
author Omar Sandoval <osandov@fb.com> 1526069617 -0700
committer David Sterba <dsterba@suse.com> 1527524634 +0200

Btrfs: fix ENOSPC caused by orphan items reservations

Currently, we keep space reserved for all inode orphan items until the
inode is evicted (i.e., all references to it are dropped). We hit an
issue where an application would keep a bunch of deleted files open (by
design) and thus keep a large amount of space reserved, causing ENOSPC
errors when other operations tried to reserve space. This long-standing
reservation isn't absolutely necessary for a couple of reasons:

- We can almost always make the reservation we need or steal from the
  global reserve for the orphan item
- If we can't, it's not the end of the world if we drop the orphan item
  on the floor and let the next mount clean it up

So, get rid of persistent reservation and just reserve space in
btrfs_evict_inode().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>