[PATCH 0/3] Btrfs: some cleanups around btrfs_read_fs_root_no_name()

[PATCH 0/3] Btrfs: some cleanups around btrfs_read_fs_root_no_name()

[Stefan Behrens]

Just some line deletions for callers of btrfs_read_fs_root_no_name().
They repeat the check for btrfs_root_refs() after calling
btrfs_read_fs_root_no_name() and map the error to ENOENT in this case,
and btrfs_read_fs_root_no_name() already does the same for you.
send.c even checked the result for NULL which cannot happen.
And one static inline function in delayed-inode.c that called
btrfs_read_fs_root_no_name() was not at all used anymore.

Stefan Behrens (3):
  Btrfs: delete unused function
  Btrfs: cleanup, btrfs_read_fs_root_no_name() doesn't return NULL
  Btrfs: cleanup: don't check the same thing twice

 fs/btrfs/delayed-inode.c | 14 --------------
 fs/btrfs/export.c        |  5 -----
 fs/btrfs/file.c          |  4 ----
 fs/btrfs/inode.c         | 10 ----------
 fs/btrfs/ioctl.c         |  5 -----
 fs/btrfs/send.c          |  8 ++------
 fs/btrfs/super.c         |  3 ---
 7 files changed, 2 insertions(+), 47 deletions(-)

-- 
1.8.2.2

[PATCH 1/3] Btrfs: delete unused function

[Stefan Behrens]

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
 fs/btrfs/delayed-inode.c | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index f26f38c..5615eac 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -535,20 +535,6 @@ static struct btrfs_delayed_item *__btrfs_next_delayed_item(
 	return next;
 }
 
-static inline struct btrfs_root *btrfs_get_fs_root(struct btrfs_root *root,
-						   u64 root_id)
-{
-	struct btrfs_key root_key;
-
-	if (root->objectid == root_id)
-		return root;
-
-	root_key.objectid = root_id;
-	root_key.type = BTRFS_ROOT_ITEM_KEY;
-	root_key.offset = (u64)-1;
-	return btrfs_read_fs_root_no_name(root->fs_info, &root_key);
-}
-
 static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 					       struct btrfs_root *root,
 					       struct btrfs_delayed_item *item)
-- 
1.8.2.2

[PATCH 2/3] Btrfs: cleanup, btrfs_read_fs_root_no_name() doesn't return NULL

[Stefan Behrens]

No need to check for NULL in send.c.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
 fs/btrfs/send.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index ff40f1c..f075c82 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -4663,10 +4663,6 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
 			key.type = BTRFS_ROOT_ITEM_KEY;
 			key.offset = (u64)-1;
 			clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
-			if (!clone_root) {
-				ret = -EINVAL;
-				goto out;
-			}
 			if (IS_ERR(clone_root)) {
 				ret = PTR_ERR(clone_root);
 				goto out;
@@ -4682,8 +4678,8 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
 		key.type = BTRFS_ROOT_ITEM_KEY;
 		key.offset = (u64)-1;
 		sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
-		if (!sctx->parent_root) {
-			ret = -EINVAL;
+		if (IS_ERR(sctx->parent_root)) {
+			ret = PTR_ERR(sctx->parent_root);
 			goto out;
 		}
 	}
-- 
1.8.2.2

[PATCH 3/3] Btrfs: cleanup: don't check the same thing twice

[Stefan Behrens]

btrfs_read_fs_root_no_name() already checks if btrfs_root_refs()
is zero and returns ENOENT in this case. There is no need to do
it again in six places.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
 fs/btrfs/export.c |  5 -----
 fs/btrfs/file.c   |  4 ----
 fs/btrfs/inode.c  | 10 ----------
 fs/btrfs/ioctl.c  |  5 -----
 fs/btrfs/super.c  |  3 ---
 5 files changed, 27 deletions(-)

diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 81ee29e..4b86916 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -82,11 +82,6 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
 		goto fail;
 	}
 
-	if (btrfs_root_refs(&root->root_item) == 0) {
-		err = -ENOENT;
-		goto fail;
-	}
-
 	key.objectid = objectid;
 	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
 	key.offset = 0;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index b3e359b..185af15 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -308,10 +308,6 @@ static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
 		ret = PTR_ERR(inode_root);
 		goto cleanup;
 	}
-	if (btrfs_root_refs(&inode_root->root_item) == 0) {
-		ret = -ENOENT;
-		goto cleanup;
-	}
 
 	key.objectid = defrag->ino;
 	btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1669c3b..0457347 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2258,11 +2258,6 @@ static noinline int relink_extent_backref(struct btrfs_path *path,
 			return 0;
 		return PTR_ERR(root);
 	}
-	if (btrfs_root_refs(&root->root_item) == 0) {
-		srcu_read_unlock(&fs_info->subvol_srcu, index);
-		/* parse ENOENT to 0 */
-		return 0;
-	}
 
 	/* step 2: get inode */
 	key.objectid = backref->inum;
@@ -4816,11 +4811,6 @@ static int fixup_tree_root_location(struct btrfs_root *root,
 		goto out;
 	}
 
-	if (btrfs_root_refs(&new_root->root_item) == 0) {
-		err = -ENOENT;
-		goto out;
-	}
-
 	*sub_root = new_root;
 	location->objectid = btrfs_root_dirid(&new_root->root_item);
 	location->type = BTRFS_INODE_ITEM_KEY;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 1e0dda1..b2537c7 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2951,11 +2951,6 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 		goto out;
 	}
 
-	if (btrfs_root_refs(&new_root->root_item) == 0) {
-		ret = -ENOENT;
-		goto out;
-	}
-
 	path = btrfs_alloc_path();
 	if (!path) {
 		ret = -ENOMEM;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index c02c59a..b6af7d3 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -775,9 +775,6 @@ find_root:
 	if (IS_ERR(new_root))
 		return ERR_CAST(new_root);
 
-	if (btrfs_root_refs(&new_root->root_item) == 0)
-		return ERR_PTR(-ENOENT);
-
 	dir_id = btrfs_root_dirid(&new_root->root_item);
 setup_root:
 	location.objectid = dir_id;
-- 
1.8.2.2