Re: [PATCH] btrfs: extent-tree.c: Remove redundant variable from btrfs_cross_ref_exist()
On Fri, Sep 07, 2018 at 12:01:21PM +0900, Misono Tomohiro wrote:
> On 2018/09/07 0:57, David Sterba wrote:
> > On Thu, Aug 30, 2018 at 10:59:16AM +0900, Misono Tomohiro wrote:
> >> Since commit d7df2c796d7e ("Btrfs attach delayed ref updates to
> >> delayed ref heads"), check_delaed_ref() won't return -ENOENT.
> >>
> >> In btrfs_cross_ref_exist(), two variable 'ret' and 'ret2' is
> >> originally used to handle -ENOENT error case.
> >>
> >> Since the code is not needed anymore, let's just remove 'ret2'.
> >
> > Good cleanup and the patch would be ok as-is. I've noticed that
> > check_delayed_ref now returns only two values so it might make sense to
> > turn it to bool and update the name of check_delayed_ref to make it
> > clear what the return value means in the loop.
>
> check_delaed_ref()'s return value is:
> 0 ... no cross ref found in delayed ref
> 1 ... cross ref found in delayed ref
> -EAGAIN ... cannot acquire lock and try again later
>
> so I don't think we can convert it to bool directly or
> do you mean we should handle -EAGAIN in check_delayed_ref()?
Oh right, I missed there's ret = 1 in one of the branches, that makes my
point moot.
Re: [PATCH] btrfs: extent-tree.c: Remove redundant variable from btrfs_cross_ref_exist()
On Thu, Aug 30, 2018 at 10:59:16AM +0900, Misono Tomohiro wrote:
> Since commit d7df2c796d7e ("Btrfs attach delayed ref updates to
> delayed ref heads"), check_delaed_ref() won't return -ENOENT.
>
> In btrfs_cross_ref_exist(), two variable 'ret' and 'ret2' is
> originally used to handle -ENOENT error case.
>
> Since the code is not needed anymore, let's just remove 'ret2'.
Good cleanup and the patch would be ok as-is. I've noticed that
check_delayed_ref now returns only two values so it might make sense to
turn it to bool and update the name of check_delayed_ref to make it
clear what the return value means in the loop.
The concern here is that adding another error code in check_delayed_ref
in the future will not be caught in btrfs_cross_ref_exist. Adding an
assert filtering only EAGAIN would be sufficient as this might miss the
extra value in case it'd be an uncommon case.
[PATCH] btrfs: extent-tree.c: Remove redundant variable from btrfs_cross_ref_exist()
Since commit d7df2c796d7e ("Btrfs attach delayed ref updates to
delayed ref heads"), check_delaed_ref() won't return -ENOENT.
In btrfs_cross_ref_exist(), two variable 'ret' and 'ret2' is
originally used to handle -ENOENT error case.
Since the code is not needed anymore, let's just remove 'ret2'.
Signed-off-by: Misono Tomohiro
---
fs/btrfs/extent-tree.c | 12 ++--
1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2d9074295d7f..0c87472d5719 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3139,7 +3139,6 @@ int btrfs_cross_ref_exist(struct btrfs_root *root, u64
objectid, u64 offset,
{
struct btrfs_path *path;
int ret;
- int ret2;
path = btrfs_alloc_path();
if (!path)
@@ -3151,17 +3150,10 @@ int btrfs_cross_ref_exist(struct btrfs_root *root, u64
objectid, u64 offset,
if (ret && ret != -ENOENT)
goto out;
- ret2 = check_delayed_ref(root, path, objectid,
+ ret = check_delayed_ref(root, path, objectid,
offset, bytenr);
- } while (ret2 == -EAGAIN);
+ } while (ret == -EAGAIN);
- if (ret2 && ret2 != -ENOENT) {
- ret = ret2;
- goto out;
- }
-
- if (ret != -ENOENT || ret2 != -ENOENT)
- ret = 0;
out:
btrfs_free_path(path);
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
--
2.17.1
