btrfs: inode: cleanup the log-tree exceptions in btrfs_truncate_inode_items()

There are a lot of root owner checks in btrfs_truncate_inode_items()
like:

	if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
	    root == fs_info->tree_root)

But considering that, only these trees can have INODE_ITEMs:

- tree root (for v1 space cache)
- subvolume trees
- tree reloc trees
- data reloc tree
- log trees

And since subvolume/tree reloc/data reloc trees all have SHAREABLE bit,
and we're checking tree root manually, so above check is just excluding
log trees.

This patch will replace two of such checks to a simpler one:

	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)

This would merge btrfs_drop_extent_cache() and lock_extent_bits() call
into the same if branch.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 08c02bd..5be7820 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4113,20 +4113,19 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
                return -ENOMEM;
        path->reada = READA_BACK;
 
-       if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+       if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
                lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, (u64)-1,
                                 &cached_state);
 
-       /*
-        * We want to drop from the next block forward in case this new size is
-        * not block aligned since we will be keeping the last block of the
-        * extent just the way it is.
-        */
-       if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
-           root == fs_info->tree_root)
+               /*
+                * We want to drop from the next block forward in case this
+                * new size is not block aligned since we will be keeping the
+                * last block of the extent just the way it is.
+                */
                btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
                                        fs_info->sectorsize),
                                        (u64)-1, 0);
+       }
 
        /*
         * This function is also used to drop the items in the log tree before
@@ -4327,8 +4326,7 @@ delete:
                should_throttle = false;
 
                if (found_extent &&
-                   (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
-                    root == fs_info->tree_root)) {
+                   root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
                        struct btrfs_ref ref = { 0 };
 
                        bytes_deleted += extent_num_bytes;