diff options
Diffstat (limited to 'fs/btrfs/delayed-ref.c')
| -rw-r--r-- | fs/btrfs/delayed-ref.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index a94fae897b3f..9a91d1eb0af4 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -10,6 +10,7 @@ #include "delayed-ref.h" #include "transaction.h" #include "qgroup.h" +#include "space-info.h" struct kmem_cache *btrfs_delayed_ref_head_cachep; struct kmem_cache *btrfs_delayed_tree_ref_cachep; @@ -24,6 +25,179 @@ struct kmem_cache *btrfs_delayed_extent_op_cachep; * of hammering updates on the extent allocation tree. */ +bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info) +{ + struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + bool ret = false; + u64 reserved; + + spin_lock(&global_rsv->lock); + reserved = global_rsv->reserved; + spin_unlock(&global_rsv->lock); + + /* + * Since the global reserve is just kind of magic we don't really want + * to rely on it to save our bacon, so if our size is more than the + * delayed_refs_rsv and the global rsv then it's time to think about + * bailing. + */ + spin_lock(&delayed_refs_rsv->lock); + reserved += delayed_refs_rsv->reserved; + if (delayed_refs_rsv->size >= reserved) + ret = true; + spin_unlock(&delayed_refs_rsv->lock); + return ret; +} + +int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans) +{ + u64 num_entries = + atomic_read(&trans->transaction->delayed_refs.num_entries); + u64 avg_runtime; + u64 val; + + smp_mb(); + avg_runtime = trans->fs_info->avg_delayed_ref_runtime; + val = num_entries * avg_runtime; + if (val >= NSEC_PER_SEC) + return 1; + if (val >= NSEC_PER_SEC / 2) + return 2; + + return btrfs_check_space_for_delayed_refs(trans->fs_info); +} + +/** + * btrfs_delayed_refs_rsv_release - release a ref head's reservation. + * @fs_info - the fs_info for our fs. + * @nr - the number of items to drop. + * + * This drops the delayed ref head's count from the delayed refs rsv and frees + * any excess reservation we had. + */ +void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr) +{ + struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv; + u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, nr); + u64 released = 0; + + released = __btrfs_block_rsv_release(fs_info, block_rsv, num_bytes, + NULL); + if (released) + trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", + 0, released, 0); +} + +/* + * btrfs_update_delayed_refs_rsv - adjust the size of the delayed refs rsv + * @trans - the trans that may have generated delayed refs + * + * This is to be called anytime we may have adjusted trans->delayed_ref_updates, + * it'll calculate the additional size and add it to the delayed_refs_rsv. + */ +void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv; + u64 num_bytes; + + if (!trans->delayed_ref_updates) + return; + + num_bytes = btrfs_calc_trans_metadata_size(fs_info, + trans->delayed_ref_updates); + spin_lock(&delayed_rsv->lock); + delayed_rsv->size += num_bytes; + delayed_rsv->full = 0; + spin_unlock(&delayed_rsv->lock); + trans->delayed_ref_updates = 0; +} + +/** + * btrfs_migrate_to_delayed_refs_rsv - transfer bytes to our delayed refs rsv. + * @fs_info - the fs info for our fs. + * @src - the source block rsv to transfer from. + * @num_bytes - the number of bytes to transfer. + * + * This transfers up to the num_bytes amount from the src rsv to the + * delayed_refs_rsv. Any extra bytes are returned to the space info. + */ +void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *src, + u64 num_bytes) +{ + struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; + u64 to_free = 0; + + spin_lock(&src->lock); + src->reserved -= num_bytes; + src->size -= num_bytes; + spin_unlock(&src->lock); + + spin_lock(&delayed_refs_rsv->lock); + if (delayed_refs_rsv->size > delayed_refs_rsv->reserved) { + u64 delta = delayed_refs_rsv->size - + delayed_refs_rsv->reserved; + if (num_bytes > delta) { + to_free = num_bytes - delta; + num_bytes = delta; + } + } else { + to_free = num_bytes; + num_bytes = 0; + } + + if (num_bytes) + delayed_refs_rsv->reserved += num_bytes; + if (delayed_refs_rsv->reserved >= delayed_refs_rsv->size) + delayed_refs_rsv->full = 1; + spin_unlock(&delayed_refs_rsv->lock); + + if (num_bytes) + trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", + 0, num_bytes, 1); + if (to_free) + btrfs_space_info_add_old_bytes(fs_info, + delayed_refs_rsv->space_info, to_free); +} + +/** + * btrfs_delayed_refs_rsv_refill - refill based on our delayed refs usage. + * @fs_info - the fs_info for our fs. + * @flush - control how we can flush for this reservation. + * + * This will refill the delayed block_rsv up to 1 items size worth of space and + * will return -ENOSPC if we can't make the reservation. + */ +int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info, + enum btrfs_reserve_flush_enum flush) +{ + struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv; + u64 limit = btrfs_calc_trans_metadata_size(fs_info, 1); + u64 num_bytes = 0; + int ret = -ENOSPC; + + spin_lock(&block_rsv->lock); + if (block_rsv->reserved < block_rsv->size) { + num_bytes = block_rsv->size - block_rsv->reserved; + num_bytes = min(num_bytes, limit); + } + spin_unlock(&block_rsv->lock); + + if (!num_bytes) + return 0; + + ret = btrfs_reserve_metadata_bytes(fs_info->extent_root, block_rsv, + num_bytes, flush); + if (ret) + return ret; + btrfs_block_rsv_add_bytes(block_rsv, num_bytes, 0); + trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", + 0, num_bytes, 1); + return 0; +} + /* * compare two delayed tree backrefs with same bytenr and type */ |