btrfs: use btrfs_try_granting_tickets in update_global_rsv

We have some annoying xfstests tests that will create a very small fs,
fill it up, delete it, and repeat to make sure everything works right.
This trips btrfs up sometimes because we may commit a transaction to
free space, but most of the free metadata space was being reserved by
the global reserve.  So we commit and update the global reserve, but the
space is simply added to bytes_may_use directly, instead of trying to
add it to existing tickets.  This results in ENOSPC when we really did
have space.  Fix this by calling btrfs_try_granting_tickets once we add
back our excess space to wake any pending tickets.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c
index bea66b499e6fcd0a9a159ced40e3714ccf1db002..d07bd41a7c1e01b2b12254802702198606796108 100644 (file)
--- a/fs/btrfs/block-rsv.c
+++ b/fs/btrfs/block-rsv.c
@@ -305,6 +305,7 @@ void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info)
                btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
                                                      -num_bytes);
                block_rsv->reserved = block_rsv->size;
+               btrfs_try_granting_tickets(fs_info, sinfo);
        }
 
        if (block_rsv->reserved == block_rsv->size)