[PATCH v2 16/16] btrfs: remove TRANS_JOIN_NOLOCK

[Tal Zussman]

btrfs_join_transaction_spacecache() was the only user of
TRANS_JOIN_NOLOCK and is gone, so remove the join type, its entries in
the blocked types table, and the special cases in join_transaction() and
start_transaction().

Assisted-by: Claude:claude-fable-5-1
Signed-off-by: Tal Zussman <tz2294@xxxxxxxxxxxx>
---
 fs/btrfs/transaction.c | 17 +----------------
 fs/btrfs/transaction.h |  2 --
 2 files changed, 1 insertion(+), 18 deletions(-)

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index ccc8d5840355..01d577cc13bc 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -125,17 +125,14 @@ static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
 	[TRANS_STATE_UNBLOCKED]		= (__TRANS_START |
 					   __TRANS_ATTACH |
 					   __TRANS_JOIN |
-					   __TRANS_JOIN_NOLOCK |
 					   __TRANS_JOIN_NOSTART),
 	[TRANS_STATE_SUPER_COMMITTED]	= (__TRANS_START |
 					   __TRANS_ATTACH |
 					   __TRANS_JOIN |
-					   __TRANS_JOIN_NOLOCK |
 					   __TRANS_JOIN_NOSTART),
 	[TRANS_STATE_COMPLETED]		= (__TRANS_START |
 					   __TRANS_ATTACH |
 					   __TRANS_JOIN |
-					   __TRANS_JOIN_NOLOCK |
 					   __TRANS_JOIN_NOSTART),
 };
 
@@ -310,12 +307,6 @@ static noinline int join_transaction(struct btrfs_fs_info *fs_info,
 	if (type == TRANS_ATTACH || type == TRANS_JOIN_NOSTART)
 		return -ENOENT;
 
-	/*
-	 * JOIN_NOLOCK only happens during the transaction commit, so
-	 * it is impossible that ->running_transaction is NULL
-	 */
-	BUG_ON(type == TRANS_JOIN_NOLOCK);
-
 	cur_trans = kmalloc_obj(*cur_trans, GFP_NOFS);
 	if (!cur_trans)
 		return -ENOMEM;
@@ -708,14 +699,8 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
 	}
 
 	/*
-	 * If we are JOIN_NOLOCK we're already committing a transaction and
-	 * waiting on this guy, so we don't need to do the sb_start_intwrite
-	 * because we're already holding a ref.  We need this because we could
-	 * have raced in and did an fsync() on a file which can kick a commit
-	 * and then we deadlock with somebody doing a freeze.
-	 *
 	 * If we are ATTACH, it means we just want to catch the current
-	 * transaction and commit it, so we needn't do sb_start_intwrite(). 
+	 * transaction and commit it, so we needn't do sb_start_intwrite().
 	 */
 	if (type & __TRANS_FREEZABLE)
 		sb_start_intwrite(fs_info->sb);
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index d2e2dd6101bc..813f0a261b21 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -100,7 +100,6 @@ enum {
 	ENUM_BIT(__TRANS_START),
 	ENUM_BIT(__TRANS_ATTACH),
 	ENUM_BIT(__TRANS_JOIN),
-	ENUM_BIT(__TRANS_JOIN_NOLOCK),
 	ENUM_BIT(__TRANS_DUMMY),
 	ENUM_BIT(__TRANS_JOIN_NOSTART),
 };
@@ -108,7 +107,6 @@ enum {
 #define TRANS_START		(__TRANS_START | __TRANS_FREEZABLE)
 #define TRANS_ATTACH		(__TRANS_ATTACH)
 #define TRANS_JOIN		(__TRANS_JOIN | __TRANS_FREEZABLE)
-#define TRANS_JOIN_NOLOCK	(__TRANS_JOIN_NOLOCK)
 #define TRANS_JOIN_NOSTART	(__TRANS_JOIN_NOSTART)
 
 #define TRANS_EXTWRITERS	(__TRANS_START | __TRANS_ATTACH)

-- 
2.39.5