1 files changed, 43 insertions, 48 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8cede6eb9843..b359d4b17658 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -21,6 +21,7 @@
 #include "dev-replace.h"
 #include "qgroup.h"
 #include "block-group.h"
+#include "space-info.h"
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
@@ -141,7 +142,7 @@ void btrfs_put_transaction(struct btrfs_transaction *transaction)
 						 struct btrfs_block_group,
 						 bg_list);
 			list_del_init(&cache->bg_list);
-			btrfs_put_block_group_trimming(cache);
+			btrfs_unfreeze_block_group(cache);
 			btrfs_put_block_group(cache);
 		}
 		WARN_ON(!list_empty(&transaction->dev_update_list));
@@ -348,10 +349,10 @@ loop:
 }
 
 /*
- * this does all the record keeping required to make sure that a reference
- * counted root is properly recorded in a given transaction.  This is required
- * to make sure the old root from before we joined the transaction is deleted
- * when the transaction commits
+ * This does all the record keeping required to make sure that a shareable root
+ * is properly recorded in a given transaction.  This is required to make sure
+ * the old root from before we joined the transaction is deleted when the
+ * transaction commits.
  */
 static int record_root_in_trans(struct btrfs_trans_handle *trans,
 			       struct btrfs_root *root,
@@ -359,7 +360,7 @@ static int record_root_in_trans(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
-	if ((test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
+	if ((test_bit(BTRFS_ROOT_SHAREABLE, &root->state) &&
 	    root->last_trans < trans->transid) || force) {
 		WARN_ON(root == fs_info->extent_root);
 		WARN_ON(!force && root->commit_root != root->node);
@@ -438,7 +439,7 @@ int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
-	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
+	if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
 		return 0;
 
 	/*
@@ -503,7 +504,7 @@ static inline bool need_reserve_reloc_root(struct btrfs_root *root)
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
 	if (!fs_info->reloc_ctl ||
-	    !test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
+	    !test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
 	    root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
 	    root->reloc_root)
 		return false;
@@ -523,6 +524,7 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
 	u64 num_bytes = 0;
 	u64 qgroup_reserved = 0;
 	bool reloc_reserved = false;
+	bool do_chunk_alloc = false;
 	int ret;
 
 	/* Send isn't supposed to start transactions. */
@@ -563,7 +565,8 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
 		 * refill that amount for whatever is missing in the reserve.
 		 */
 		num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items);
-		if (delayed_refs_rsv->full == 0) {
+		if (flush == BTRFS_RESERVE_FLUSH_ALL &&
+		    delayed_refs_rsv->full == 0) {
 			delayed_refs_bytes = num_bytes;
 			num_bytes <<= 1;
 		}
@@ -584,6 +587,9 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
 							  delayed_refs_bytes);
 			num_bytes -= delayed_refs_bytes;
 		}
+
+		if (rsv->space_info->force_alloc)
+			do_chunk_alloc = true;
 	} else if (num_items == 0 && flush == BTRFS_RESERVE_FLUSH_ALL &&
 		   !delayed_refs_rsv->full) {
 		/*
@@ -662,10 +668,32 @@ again:
 	}
 
 got_it:
-	btrfs_record_root_in_trans(h, root);
-
 	if (!current->journal_info)
 		current->journal_info = h;
+
+	/*
+	 * If the space_info is marked ALLOC_FORCE then we'll get upgraded to
+	 * ALLOC_FORCE the first run through, and then we won't allocate for
+	 * anybody else who races in later.  We don't care about the return
+	 * value here.
+	 */
+	if (do_chunk_alloc && num_bytes) {
+		u64 flags = h->block_rsv->space_info->flags;
+
+		btrfs_chunk_alloc(h, btrfs_get_alloc_profile(fs_info, flags),
+				  CHUNK_ALLOC_NO_FORCE);
+	}
+
+	/*
+	 * btrfs_record_root_in_trans() needs to alloc new extents, and may
+	 * call btrfs_join_transaction() while we're also starting a
+	 * transaction.
+	 *
+	 * Thus it need to be called after current->journal_info initialized,
+	 * or we can deadlock.
+	 */
+	btrfs_record_root_in_trans(h, root);
+
 	return h;
 
 join_fail:
@@ -690,43 +718,10 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 
 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
 					struct btrfs_root *root,
-					unsigned int num_items,
-					int min_factor)
+					unsigned int num_items)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_trans_handle *trans;
-	u64 num_bytes;
-	int ret;
-
-	/*
-	 * We have two callers: unlink and block group removal.  The
-	 * former should succeed even if we will temporarily exceed
-	 * quota and the latter operates on the extent root so
-	 * qgroup enforcement is ignored anyway.
-	 */
-	trans = start_transaction(root, num_items, TRANS_START,
-				  BTRFS_RESERVE_FLUSH_ALL, false);
-	if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
-		return trans;
-
-	trans = btrfs_start_transaction(root, 0);
-	if (IS_ERR(trans))
-		return trans;
-
-	num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items);
-	ret = btrfs_cond_migrate_bytes(fs_info, &fs_info->trans_block_rsv,
-				       num_bytes, min_factor);
-	if (ret) {
-		btrfs_end_transaction(trans);
-		return ERR_PTR(ret);
-	}
-
-	trans->block_rsv = &fs_info->trans_block_rsv;
-	trans->bytes_reserved = num_bytes;
-	trace_btrfs_space_reservation(fs_info, "transaction",
-				      trans->transid, num_bytes, 1);
-
-	return trans;
+	return start_transaction(root, num_items, TRANS_START,
+				 BTRFS_RESERVE_FLUSH_ALL_STEAL, false);
 }
 
 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
@@ -1635,7 +1630,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	}
 
 	key.offset = (u64)-1;
-	pending->snap = btrfs_get_fs_root(fs_info, &key, true);
+	pending->snap = btrfs_get_fs_root(fs_info, objectid, true);
 	if (IS_ERR(pending->snap)) {
 		ret = PTR_ERR(pending->snap);
 		btrfs_abort_transaction(trans, ret);