btrfs: move extent locking outside of btrfs_truncate_inode_items

Currently we are locking the extent and dropping the extent cache for
any inodes we truncate, unless they're in the tree log.  We call this
helper from:

- truncate
- evict
- tree log
- free space cache truncation

For evict we've already dropped all of the extent cache for this inode
once we've gotten here, and we're the only one accessing this inode, so
this step is unnecessary.

For the tree log code we already skip this part.

Pull this work into the truncate path and the free space cache
truncation path.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 55e1be703a39..28b9c63ba536 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -289,9 +289,11 @@ int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
 
 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
 				    struct btrfs_block_group *block_group,
-				    struct inode *inode)
+				    struct inode *vfs_inode)
 {
-	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_inode *inode = BTRFS_I(vfs_inode);
+	struct btrfs_root *root = inode->root;
+	struct extent_state *cached_state = NULL;
 	int ret = 0;
 	bool locked = false;
 
@@ -321,19 +323,23 @@ int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
 		btrfs_free_path(path);
 	}
 
-	btrfs_i_size_write(BTRFS_I(inode), 0);
-	truncate_pagecache(inode, 0);
+	btrfs_i_size_write(inode, 0);
+	truncate_pagecache(vfs_inode, 0);
+
+	lock_extent_bits(&inode->io_tree, 0, (u64)-1, &cached_state);
+	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
 
 	/*
 	 * We skip the throttling logic for free space cache inodes, so we don't
 	 * need to check for -EAGAIN.
 	 */
-	ret = btrfs_truncate_inode_items(trans, root, BTRFS_I(inode),
-					 0, BTRFS_EXTENT_DATA_KEY, NULL);
+	ret = btrfs_truncate_inode_items(trans, root, inode, 0,
+					 BTRFS_EXTENT_DATA_KEY, NULL);
+	unlock_extent_cached(&inode->io_tree, 0, (u64)-1, &cached_state);
 	if (ret)
 		goto fail;
 
-	ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
+	ret = btrfs_update_inode(trans, root, inode);
 
 fail:
 	if (locked)