Btrfs: enforce min_bytes parameter during extent allocation
Commit 24542bf7ea5e4fdfdb5157ff544c093fa4dcb536 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>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ecd9c4c..13ab4de 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8502,6 +8502,7 @@
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 @@
}
}
- 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)