btrfs: don't refill whole delayed refs block reserve when starting transaction

[thirdparty/linux.git] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 5b3333ceef04818dbf98270da4bb84c99e5c70f8..c52807d97efa553b0b5e4765e11606a8ce644161 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -564,56 +564,22 @@ static int btrfs_reserve_trans_metadata(struct btrfs_fs_info *fs_info,
                                        u64 num_bytes,
                                        u64 *delayed_refs_bytes)
 {
-       struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv;
        struct btrfs_space_info *si = fs_info->trans_block_rsv.space_info;
-       u64 extra_delayed_refs_bytes = 0;
-       u64 bytes;
+       u64 bytes = num_bytes + *delayed_refs_bytes;
        int ret;
 
-       /*
-        * If there's a gap between the size of the delayed refs reserve and
-        * its reserved space, than some tasks have added delayed refs or bumped
-        * its size otherwise (due to block group creation or removal, or block
-        * group item update). Also try to allocate that gap in order to prevent
-        * using (and possibly abusing) the global reserve when committing the
-        * transaction.
-        */
-       if (flush == BTRFS_RESERVE_FLUSH_ALL &&
-           !btrfs_block_rsv_full(delayed_refs_rsv)) {
-               spin_lock(&delayed_refs_rsv->lock);
-               if (delayed_refs_rsv->size > delayed_refs_rsv->reserved)
-                       extra_delayed_refs_bytes = delayed_refs_rsv->size -
-                               delayed_refs_rsv->reserved;
-               spin_unlock(&delayed_refs_rsv->lock);
-       }
-
-       bytes = num_bytes + *delayed_refs_bytes + extra_delayed_refs_bytes;
-
        /*
         * We want to reserve all the bytes we may need all at once, so we only
         * do 1 enospc flushing cycle per transaction start.
         */
        ret = btrfs_reserve_metadata_bytes(fs_info, si, bytes, flush);
-       if (ret == 0) {
-               if (extra_delayed_refs_bytes > 0)
-                       btrfs_migrate_to_delayed_refs_rsv(fs_info,
-                                                         extra_delayed_refs_bytes);
-               return 0;
-       }
-
-       if (extra_delayed_refs_bytes > 0) {
-               bytes -= extra_delayed_refs_bytes;
-               ret = btrfs_reserve_metadata_bytes(fs_info, si, bytes, flush);
-               if (ret == 0)
-                       return 0;
-       }
 
        /*
         * If we are an emergency flush, which can steal from the global block
         * reserve, then attempt to not reserve space for the delayed refs, as
         * we will consume space for them from the global block reserve.
         */
-       if (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL) {
+       if (ret && flush == BTRFS_RESERVE_FLUSH_ALL_STEAL) {
                bytes -= *delayed_refs_bytes;
                *delayed_refs_bytes = 0;
                ret = btrfs_reserve_metadata_bytes(fs_info, si, bytes, flush);