Btrfs: do not allocate chunks as agressively

Swinging this pendulum back the other way.  We've been allocating chunks up
to 2% of the disk no matter how much we actually have allocated.  So instead
fix this calculation to only allocate chunks if we have more than 80% of the
space available allocated.  Please test this as it will likely cause all
sorts of ENOSPC problems to pop up suddenly.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Josef Bacik 2012-08-14 16:20:52 -04:00 committed by Chris Mason
parent 7c735313bd
commit 54338b5cc4

View File

@ -3504,7 +3504,8 @@ static int should_alloc_chunk(struct btrfs_root *root,
* and purposes it's used space. Don't worry about locking the
* global_rsv, it doesn't change except when the transaction commits.
*/
num_allocated += global_rsv->size;
if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
num_allocated += global_rsv->size;
/*
* in limited mode, we want to have some free space up to
@ -3518,15 +3519,8 @@ static int should_alloc_chunk(struct btrfs_root *root,
if (num_bytes - num_allocated < thresh)
return 1;
}
thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
/* 256MB or 2% of the FS */
thresh = max_t(u64, 256 * 1024 * 1024, div_factor_fine(thresh, 2));
/* system chunks need a much small threshold */
if (sinfo->flags & BTRFS_BLOCK_GROUP_SYSTEM)
thresh = 32 * 1024 * 1024;
if (num_bytes > thresh && sinfo->bytes_used < div_factor(num_bytes, 8))
if (num_allocated + alloc_bytes < div_factor(num_bytes, 8))
return 0;
return 1;
}