From 7e355b83efa80e5f5821591c13c17649594d82ac Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 18 Oct 2011 13:07:31 -0400 Subject: [PATCH] Btrfs: if we have a lot of pinned space, commit the transaction Mitch kept hitting a panic because he was getting ENOSPC. One of my previous patches makes it so we are much better at not allocating new metadata chunks. Unfortunately coupled with the overcommit patch this works us into a bit of a problem if we are removing a bunch of space and end up chewing up all of our space with pinned extents. We can allocate chunks fine and overflow is ok, but the only way to reclaim this space is to commit the transaction. So if we go to overcommit, first check and see how much pinned space we have. If we have more than 80% of the free space chewed up with pinned extents, just commit the transaction, this will free up enough space for our reservation and we won't have this problem anymore. With this patch Mitch's test doesn't blow up anymore. Thanks, Reported-and-tested-by: Mitch Harder Signed-off-by: Josef Bacik --- fs/btrfs/extent-tree.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a5f1421eeee9..4eb7d2ba38f8 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3510,6 +3510,20 @@ again: u64 profile = btrfs_get_alloc_profile(root, 0); u64 avail; + /* + * If we have a lot of space that's pinned, don't bother doing + * the overcommit dance yet and just commit the transaction. + */ + avail = (space_info->total_bytes - space_info->bytes_used) * 8; + do_div(avail, 10); + if (space_info->bytes_pinned >= avail && flush && !trans && + !committed) { + space_info->flush = 1; + flushing = true; + spin_unlock(&space_info->lock); + goto commit; + } + spin_lock(&root->fs_info->free_chunk_lock); avail = root->fs_info->free_chunk_space; @@ -3581,6 +3595,7 @@ again: if (trans) goto out; +commit: ret = -ENOSPC; if (committed) goto out; -- 2.30.2