diff options
author | David Sterba <dsterba@suse.cz> | 2015-11-19 14:15:51 +0100 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2016-01-07 14:26:58 +0100 |
commit | 8089fe62c6603860f6796ca80519b92391292f21 (patch) | |
tree | da517c3481f00b43a364ad14c51d496d73fcdf77 | |
parent | c5ca87819d7f10625b0940b356adb8ac0f1080d7 (diff) |
btrfs: put delayed item hook into inode
Inodes for delayed iput allocate a trivial helper structure, let's place
the list hook directly into the inode and save a kmalloc (killing a
__GFP_NOFAIL as a bonus) at the cost of increasing size of btrfs_inode.
The inode can be put into the delayed_iputs list more than once and we
have to keep the count. This means we can't use the list_splice to
process a bunch of inodes because we'd lost track of the count if the
inode is put into the delayed iputs again while it's processed.
Signed-off-by: David Sterba <dsterba@suse.com>
-rw-r--r-- | fs/btrfs/btrfs_inode.h | 4 | ||||
-rw-r--r-- | fs/btrfs/inode.c | 56 |
2 files changed, 29 insertions, 31 deletions
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 0ef5cc13fae2..61205e3bbefa 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -192,6 +192,10 @@ struct btrfs_inode { /* File creation time. */ struct timespec i_otime; + /* Hook into fs_info->delayed_iputs */ + struct list_head delayed_iput; + long delayed_iput_count; + struct inode vfs_inode; }; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e8d9f9c8d00d..255d0f966b9f 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3106,55 +3106,47 @@ static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, start, (size_t)(end - start + 1)); } -struct delayed_iput { - struct list_head list; - struct inode *inode; -}; - -/* JDM: If this is fs-wide, why can't we add a pointer to - * btrfs_inode instead and avoid the allocation? */ void btrfs_add_delayed_iput(struct inode *inode) { struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; - struct delayed_iput *delayed; + struct btrfs_inode *binode = BTRFS_I(inode); if (atomic_add_unless(&inode->i_count, -1, 1)) return; - delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); - delayed->inode = inode; - spin_lock(&fs_info->delayed_iput_lock); - list_add_tail(&delayed->list, &fs_info->delayed_iputs); + 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++; + } spin_unlock(&fs_info->delayed_iput_lock); } void btrfs_run_delayed_iputs(struct btrfs_root *root) { - LIST_HEAD(list); struct btrfs_fs_info *fs_info = root->fs_info; - struct delayed_iput *delayed; - int empty; - - spin_lock(&fs_info->delayed_iput_lock); - empty = list_empty(&fs_info->delayed_iputs); - spin_unlock(&fs_info->delayed_iput_lock); - if (empty) - return; down_read(&fs_info->delayed_iput_sem); - spin_lock(&fs_info->delayed_iput_lock); - list_splice_init(&fs_info->delayed_iputs, &list); - spin_unlock(&fs_info->delayed_iput_lock); - - while (!list_empty(&list)) { - delayed = list_entry(list.next, struct delayed_iput, list); - list_del(&delayed->list); - iput(delayed->inode); - kfree(delayed); + while (!list_empty(&fs_info->delayed_iputs)) { + struct btrfs_inode *inode; + + 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); + } + spin_unlock(&fs_info->delayed_iput_lock); + iput(&inode->vfs_inode); + spin_lock(&fs_info->delayed_iput_lock); } - + spin_unlock(&fs_info->delayed_iput_lock); up_read(&root->fs_info->delayed_iput_sem); } @@ -9037,6 +9029,7 @@ 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; @@ -9061,6 +9054,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) mutex_init(&ei->delalloc_mutex); btrfs_ordered_inode_tree_init(&ei->ordered_tree); INIT_LIST_HEAD(&ei->delalloc_inodes); + INIT_LIST_HEAD(&ei->delayed_iput); RB_CLEAR_NODE(&ei->rb_node); return inode; |