On 2020/3/11 上午8:50, David Sterba wrote: > On Tue, Mar 10, 2020 at 04:14:15PM +0800, Qu Wenruo wrote: >> In relocation, we need to locate all parent tree leaves referring one >> data extent, thus we have a complex mechanism to iterate throught extent >> tree and subvolume trees to locate related leaves. >> >> However this is already done in backref.c, we have >> btrfs_find_all_leaves(), which can return a ulist containing all leaves >> referring to that data extent. >> >> Use btrfs_find_all_leaves() to replace find_data_references(). >> >> There is a special handling for v1 space cache data extents, where we >> need to delete the v1 space cache data extents, to avoid those data >> extents to hang the data relocation. >> >> In this patch, the special handling is done by re-iterating the root >> tree leaf. >> Although it's a little less efficient than the old handling, considering >> we can reuse a lot of code, it should be acceptable. >> >> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx> >> --- >> This patch is originally in my backref cache branch, but since it's >> pretty independent from other backref cache code, and straightforward to >> test/review, it's sent for more comprehensive test/review/merge. > > I'll add the patch to for-next, looks a bit scary. > Thanks. It survives the regular balance/replace/volume groups run. And any behavior change in the v1 space cache handling would lead to 100% reproducible hang in btrfs/061, so it shouldn't be that scary. Thanks, Qu
Attachment:
signature.asc
Description: OpenPGP digital signature
