| Message ID | cover.1631117101.git.johannes.thumshirn@wdc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | btrfs: zoned: unify relocation on a zoned and regular FS | expand |
On Thu, Sep 09, 2021 at 01:19:24AM +0900, Johannes Thumshirn wrote: > A while ago David reported a bug in zoned btrfs' relocation code. The bug is > triggered because relocation on a zoned filesystem does not preallocate the > extents it copies and a writeback process running in parallel can cause a > split of the written extent. But splitting extents is currently not allowed on > relocation as it assumes a one to one copy of the relocated extents. > > This causes transaction aborts and the filessytem switching to read-only in > order to prevent further damage. > > The first patch in this series is just a preparation to avoid overly long > lines in follow up patches. Patch number two adds a dedicated block group for > relocation on a zoned filesystem. Number three excludes multiple processes > from adding pages to a relocation inode in a zoned filesystem. Patch four > switches relocation from REQ_OP_ZONE_APPEND to regular REQ_OP_WRITE, five > prepares an ASSERT()ion that we can enter the nocow path on a zoned filesystem > under very special circumstances and the sixth patch then switches the > relocation code for a zoned filesystem to using the same code path as we use > on a non zoned filesystem. As the changes before have made the prerequisites > to do so. The last two patches in this series are just a simple rename of a > function whose name we have twice in the btrfs codebase but with a different > purpose in different files and a cleanup of a complicated boolean comparison > into an if to make it stand out. > > Changes to v1: > - Added patches 3 and 8 > - Added comments to patches 4 and 5 (Naohiro) > - Move btrfs_clear_data_reloc_bg() out of line (David) > - Untangle the 'skip' assing into an if (David) > - Commented new fs_info members (David) > > Johannes Thumshirn (8): > btrfs: introduce btrfs_is_data_reloc_root > btrfs: zoned: add a dedicated data relocation block group > btrfs: zoned: only allow one process to add pages to a relocation > inode > btrfs: zoned: use regular writes for relocation > btrfs: check for relocation inodes on zoned btrfs in should_nocow > btrfs: zoned: allow preallocation for relocation inodes > btrfs: rename setup_extent_mapping in relocation code > btrfs: zoned: let the for_treelog test in the allocator stand out I did a few minor fixups, patches moved from topic branch to misc-next. Thanks.
On 13/09/2021 17:51, David Sterba wrote: > > I did a few minor fixups, patches moved from topic branch to misc-next. > Thanks. > Thanks.
A while ago David reported a bug in zoned btrfs' relocation code. The bug is triggered because relocation on a zoned filesystem does not preallocate the extents it copies and a writeback process running in parallel can cause a split of the written extent. But splitting extents is currently not allowed on relocation as it assumes a one to one copy of the relocated extents. This causes transaction aborts and the filessytem switching to read-only in order to prevent further damage. The first patch in this series is just a preparation to avoid overly long lines in follow up patches. Patch number two adds a dedicated block group for relocation on a zoned filesystem. Number three excludes multiple processes from adding pages to a relocation inode in a zoned filesystem. Patch four switches relocation from REQ_OP_ZONE_APPEND to regular REQ_OP_WRITE, five prepares an ASSERT()ion that we can enter the nocow path on a zoned filesystem under very special circumstances and the sixth patch then switches the relocation code for a zoned filesystem to using the same code path as we use on a non zoned filesystem. As the changes before have made the prerequisites to do so. The last two patches in this series are just a simple rename of a function whose name we have twice in the btrfs codebase but with a different purpose in different files and a cleanup of a complicated boolean comparison into an if to make it stand out. Changes to v1: - Added patches 3 and 8 - Added comments to patches 4 and 5 (Naohiro) - Move btrfs_clear_data_reloc_bg() out of line (David) - Untangle the 'skip' assing into an if (David) - Commented new fs_info members (David) Johannes Thumshirn (8): btrfs: introduce btrfs_is_data_reloc_root btrfs: zoned: add a dedicated data relocation block group btrfs: zoned: only allow one process to add pages to a relocation inode btrfs: zoned: use regular writes for relocation btrfs: check for relocation inodes on zoned btrfs in should_nocow btrfs: zoned: allow preallocation for relocation inodes btrfs: rename setup_extent_mapping in relocation code btrfs: zoned: let the for_treelog test in the allocator stand out fs/btrfs/block-group.c | 1 + fs/btrfs/ctree.h | 12 +++++++++ fs/btrfs/disk-io.c | 3 ++- fs/btrfs/extent-tree.c | 60 +++++++++++++++++++++++++++++++++++++----- fs/btrfs/extent_io.c | 7 +++++ fs/btrfs/inode.c | 29 +++++++++++--------- fs/btrfs/relocation.c | 43 +++++------------------------- fs/btrfs/zoned.c | 21 +++++++++++++++ fs/btrfs/zoned.h | 4 ++- 9 files changed, 123 insertions(+), 57 deletions(-)