| Message ID | 1614675476-79534-1-git-send-email-yang.lee@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: turn btrfs_destroy_all_ordered_extents() into void functions | expand |
On Tue, Mar 02, 2021 at 04:57:56PM +0800, Yang Li wrote: > These functions always return '0' and no callers use the return > value. So make it a void function. The reasoning needs to go the other way around: you can make a function return void iff all callees also return void and don't do BUG_ON instead of proper error handling. Which in this case does not hold, because the function itself still does BUG_ON. > It fixes the following warning detected by coccinelle: > ./fs/btrfs/disk-io.c:4522:5-8: Unneeded variable: "ret". Return "0" on > line 4530 Yeah tools can identify the simple cases but fixing that properly needs to extend to the whole callgraph and understand all the contexts where local data are undone and errors propagated up the callchanin.
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 41b718c..7c9e1b4 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -4513,13 +4513,12 @@ static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info) btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); } -static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, +static void btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, struct btrfs_fs_info *fs_info) { struct rb_node *node; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_ref_node *ref; - int ret = 0; delayed_refs = &trans->delayed_refs; @@ -4527,7 +4526,7 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, if (atomic_read(&delayed_refs->num_entries) == 0) { spin_unlock(&delayed_refs->lock); btrfs_debug(fs_info, "delayed_refs has NO entry"); - return ret; + return; } while ((node = rb_first_cached(&delayed_refs->href_root)) != NULL) { @@ -4593,7 +4592,7 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, spin_unlock(&delayed_refs->lock); - return ret; + return; } static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
These functions always return '0' and no callers use the return value. So make it a void function. It fixes the following warning detected by coccinelle: ./fs/btrfs/disk-io.c:4522:5-8: Unneeded variable: "ret". Return "0" on line 4530 Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> --- fs/btrfs/disk-io.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)