Because the ENOSPC code over reserves super aggressively we end up allocating
chunks way more often than we should. For example with my fs_mark tests on a
2gb fs I can end up reserved 1gb just for metadata, when only 34mb of that is
being used. So instead check to see if the amount of space actually used is
less than 30% of the total space, and if so don't allocate a chunk.
Signed-off-by: Josef Bacik <josef@xxxxxxxxxx>
---
fs/btrfs/extent-tree.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 14a52dd..265d8e0 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3224,7 +3224,8 @@ static void force_metadata_allocation(struct btrfs_fs_info *info)
rcu_read_unlock();
}
-static int should_alloc_chunk(struct btrfs_space_info *sinfo,
+static int should_alloc_chunk(struct btrfs_fs_info *info,
+ struct btrfs_space_info *sinfo,
u64 alloc_bytes)
{
u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
@@ -3237,6 +3238,9 @@ static int should_alloc_chunk(struct btrfs_space_info *sinfo,
alloc_bytes < div_factor(num_bytes, 8))
return 0;
+ if (sinfo->bytes_used < div_factor(num_bytes, 3))
+ return 0;
+
return 1;
}
@@ -3268,7 +3272,7 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans,
goto out;
}
- if (!force && !should_alloc_chunk(space_info, alloc_bytes)) {
+ if (!force && !should_alloc_chunk(fs_info, space_info, alloc_bytes)) {
spin_unlock(&space_info->lock);
goto out;
}
@@ -3317,7 +3321,8 @@ static int maybe_allocate_chunk(struct btrfs_trans_handle *trans,
return 0;
spin_lock(&sinfo->lock);
- ret = should_alloc_chunk(sinfo, num_bytes + 2 * 1024 * 1024);
+ ret = should_alloc_chunk(root->fs_info, sinfo,
+ num_bytes + 2 * 1024 * 1024);
spin_unlock(&sinfo->lock);
if (!ret)
return 0;
--
1.6.6.1
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