| Message ID | cover.1644469146.git.naohiro.aota@wdc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | btrfs: zoned: mark relocation as writing | expand |
On 10/02/2022 06:59, Naohiro Aota wrote: > There is a hung_task issue with running generic/068 on an SMR > device. The hang occurs while a process is trying to thaw the > filesystem. The process is trying to take sb->s_umount to thaw the > FS. The lock is held by fsstress, which calls btrfs_sync_fs() and is > waiting for an ordered extent to finish. However, as the FS is frozen, > the ordered extent never finish. > > Having an ordered extent while the FS is frozen is the root cause of > the hang. The ordered extent is initiated from btrfs_relocate_chunk() > which is called from btrfs_reclaim_bgs_work(). > > The first patch is a preparation patch to add asserting functions to > check if sb_start_{write,pagefault,intwrite} is called. > > The second patch adds sb_{start,end}_write and the assert function at > proper places. > > Changelog: > v2: > - Implement asserting functions not to directly touch the internal > implementation > > Naohiro Aota (2): > fs: add asserting functions for sb_start_{write,pagefault,intwrite} > btrfs: zoned: mark relocation as writing > > fs/btrfs/block-group.c | 8 +++++++- > fs/btrfs/volumes.c | 6 ++++++ > include/linux/fs.h | 20 ++++++++++++++++++++ > 3 files changed, 33 insertions(+), 1 deletion(-) > For the series: Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
On Thu, Feb 10, 2022 at 02:59:03PM +0900, Naohiro Aota wrote: > There is a hung_task issue with running generic/068 on an SMR > device. The hang occurs while a process is trying to thaw the > filesystem. The process is trying to take sb->s_umount to thaw the > FS. The lock is held by fsstress, which calls btrfs_sync_fs() and is > waiting for an ordered extent to finish. However, as the FS is frozen, > the ordered extent never finish. > > Having an ordered extent while the FS is frozen is the root cause of > the hang. The ordered extent is initiated from btrfs_relocate_chunk() > which is called from btrfs_reclaim_bgs_work(). > > The first patch is a preparation patch to add asserting functions to > check if sb_start_{write,pagefault,intwrite} is called. > > The second patch adds sb_{start,end}_write and the assert function at > proper places. > > Changelog: > v2: > - Implement asserting functions not to directly touch the internal > implementation > > Naohiro Aota (2): > fs: add asserting functions for sb_start_{write,pagefault,intwrite} > btrfs: zoned: mark relocation as writing Added as topic branch to for-next. I'd appreciate acks for the sb_start_* helpers before the patches go to to Linus' tree.
There is a hung_task issue with running generic/068 on an SMR device. The hang occurs while a process is trying to thaw the filesystem. The process is trying to take sb->s_umount to thaw the FS. The lock is held by fsstress, which calls btrfs_sync_fs() and is waiting for an ordered extent to finish. However, as the FS is frozen, the ordered extent never finish. Having an ordered extent while the FS is frozen is the root cause of the hang. The ordered extent is initiated from btrfs_relocate_chunk() which is called from btrfs_reclaim_bgs_work(). The first patch is a preparation patch to add asserting functions to check if sb_start_{write,pagefault,intwrite} is called. The second patch adds sb_{start,end}_write and the assert function at proper places. Changelog: v2: - Implement asserting functions not to directly touch the internal implementation Naohiro Aota (2): fs: add asserting functions for sb_start_{write,pagefault,intwrite} btrfs: zoned: mark relocation as writing fs/btrfs/block-group.c | 8 +++++++- fs/btrfs/volumes.c | 6 ++++++ include/linux/fs.h | 20 ++++++++++++++++++++ 3 files changed, 33 insertions(+), 1 deletion(-)