btrfs: remove no longer used trans_list member of struct btrfs_ordered_extent

The 'trans_list' member of an ordered extent was used to keep track of the
ordered extents for which a transaction commit had to wait. These were
ordered extents that were started and logged by an fsync. However we don't
do that anymore and before we stopped doing it we changed the approach to
wait for the ordered extents in commit 03cc5a9bbe56fa ("Btrfs: change how
we wait for pending ordered extents"), which stopped using that list and
therefore the 'trans_list' member is not used anymore since that commit.
So just remove it since it's doing nothing and making each ordered extent
structure waste memory (2 pointers).

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index fd902996a1dbfd1f6f8701acc01a509edc8337eb..933efe52ec2c3681ad511fd7cb09942b22bf5657 100644 (file)
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -217,7 +217,6 @@ static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
        INIT_LIST_HEAD(&entry->root_extent_list);
        INIT_LIST_HEAD(&entry->work_list);
        init_completion(&entry->completion);
-       INIT_LIST_HEAD(&entry->trans_list);
 
        trace_btrfs_ordered_extent_add(inode, entry);
 
@@ -448,7 +447,6 @@ void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
        trace_btrfs_ordered_extent_put(entry->inode, entry);
 
        if (refcount_dec_and_test(&entry->refs)) {
-               ASSERT(list_empty(&entry->trans_list));
                ASSERT(list_empty(&entry->root_extent_list));
                ASSERT(RB_EMPTY_NODE(&entry->rb_node));
                if (entry->inode)

diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 435f93c46c32495884d4aac7a9a28e0e147ab455..a24a1f2d5f9d92210c4771655e3c38d2a763a1d2 100644 (file)
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -104,9 +104,6 @@ struct btrfs_ordered_extent {
        /* list of checksums for insertion when the extent io is done */
        struct list_head list;
 
-       /* If the transaction needs to wait on this ordered extent */
-       struct list_head trans_list;
-
        /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
        wait_queue_head_t wait;