| Message ID | 90c3c33c-0f7d-7121-feb8-4a74e5e78b93@jp.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: extent-tree.c: Remove redundant variable from btrfs_cross_ref_exist() | expand |
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.
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()? > 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.
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.
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)
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 <misono.tomohiro@jp.fujitsu.com> --- fs/btrfs/extent-tree.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-)