Commit 154ea289 authored Mar 05, 2013 by Chris Mason

Btrfs: enforce min_bytes parameter during extent allocation



Commit 24542bf7 changed preallocation of
extents to cap the max size we try to allocate.  It's a valid change,
but the extent reservation code is also used by balance, and that
can't tolerate a smaller extent being allocated.

__btrfs_prealloc_file_range already has a min_size parameter, which is
used by relocation to request a specific extent size.  This commit
adds an extra check to enforce that minimum extent size.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Reported-by: Stefan Behrens <sbehrens@giantdisaster.de>

parent d7011f5b

fs/btrfs/inode.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -8502,6 +8502,7 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
		struct btrfs_key ins;
		u64 cur_offset = start;
		u64 i_size;
		u64 cur_bytes;
		int ret = 0;
		bool own_trans = true;

		@@ -8516,8 +8517,9 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
		}
		}

		ret = btrfs_reserve_extent(trans, root,
		min(num_bytes, 256ULL * 1024 * 1024),
		cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
		cur_bytes = max(cur_bytes, min_size);
		ret = btrfs_reserve_extent(trans, root, cur_bytes,
		min_size, 0, *alloc_hint, &ins, 1);
		if (ret) {
		if (own_trans)