From c1c3fac2a95b14e36333528e408e76d90c93bbf7 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Tue, 16 Jan 2018 09:31:58 +0200 Subject: [PATCH] btrfs: Remove btrfs_inode::delayed_iput_count delayed_iput_count wa supposed to be used to implement, well, delayed iput. The idea is that we keep accumulating the number of iputs we do until eventually the inode is deleted. Turns out we never really switched the delayed_iput_count from 0 to 1, hence all conditional code relying on the value of that member being different than 0 was never executed. This, as it turns out, didn't cause any problem due to the simple fact that the generic inode's i_count member was always used to count the number of iputs. So let's just remove the unused member and all unused code. This patch essentially provides no functional changes. While at it, also add proper documentation for btrfs_add_delayed_iput Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba [ reformat comment ] Signed-off-by: David Sterba --- fs/btrfs/btrfs_inode.h | 1 - fs/btrfs/inode.c | 27 +++++++++++++-------------- 2 files changed, 13 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 63f0ccc..f527e99 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -195,7 +195,6 @@ struct btrfs_inode { /* Hook into fs_info->delayed_iputs */ struct list_head delayed_iput; - long delayed_iput_count; /* * To avoid races between lockless (i_mutex not held) direct IO writes diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 4d3a4d1..b55b47f 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3242,6 +3242,16 @@ static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, start, (size_t)(end - start + 1)); } +/* + * btrfs_add_delayed_iput - perform a delayed iput on @inode + * + * @inode: The inode we want to perform iput on + * + * This function uses the generic vfs_inode::i_count to track whether we should + * just decrement it (in case it's > 1) or if this is the last iput then link + * the inode to the delayed iput machinery. Delayed iputs are processed at + * transaction commit time/superblock commit/cleaner kthread. + */ void btrfs_add_delayed_iput(struct inode *inode) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); @@ -3251,12 +3261,8 @@ void btrfs_add_delayed_iput(struct inode *inode) return; spin_lock(&fs_info->delayed_iput_lock); - if (binode->delayed_iput_count == 0) { - ASSERT(list_empty(&binode->delayed_iput)); - list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs); - } else { - binode->delayed_iput_count++; - } + ASSERT(list_empty(&binode->delayed_iput)); + list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs); spin_unlock(&fs_info->delayed_iput_lock); } @@ -3269,13 +3275,7 @@ void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info) inode = list_first_entry(&fs_info->delayed_iputs, struct btrfs_inode, delayed_iput); - if (inode->delayed_iput_count) { - inode->delayed_iput_count--; - list_move_tail(&inode->delayed_iput, - &fs_info->delayed_iputs); - } else { - list_del_init(&inode->delayed_iput); - } + list_del_init(&inode->delayed_iput); spin_unlock(&fs_info->delayed_iput_lock); iput(&inode->vfs_inode); spin_lock(&fs_info->delayed_iput_lock); @@ -9333,7 +9333,6 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) ei->dir_index = 0; ei->last_unlink_trans = 0; ei->last_log_commit = 0; - ei->delayed_iput_count = 0; spin_lock_init(&ei->lock); ei->outstanding_extents = 0; -- 2.7.4