[PATCH v3 0/2] btrfs: fix data corruption/rsv leak in subpage zoned cases

[Qu Wenruo <wqu@suse.com>]

[CHANGELOG]
v3:
- Use the minimal fsstress workload with trace_printk() output to
  explain the bug better

v2:
- Update the commit message for the first patch
  As there is something wrong with the ASCII art of the memory layout.

[REPO]
https://github.com/adam900710/linux/tree/subpage_delalloc

The repo includes the subpage delalloc rework, or subpage zoned won't
work at all.


Although my previous subpage delalloc rework fixes quite a lot of
crashes of subpage + zoned support, it's still pretty easy to cause rsv
leak using single thread fsstress.

It turns out that, it's not a simple problem of some rsv leak, but
certain dirty data ranges never got written back and just skipped with
its dirty flags cleared, no wonder that would lead to rsv leak.

The root cause is again in the extent_write_locked_range() function
doing weird subpage incompatible behaviors, especially when it clears
the page dirty flag for the whole page, causing __extent_writepage_io()
unable to locate further dirty ranges to be submitted.

The first patch would solve the problem, meanwhile for the 2nd patch
it's a cleanup, as we will never hit the error for current subpage +
zoned cases.

Qu Wenruo (2):
  btrfs: do not clear page dirty inside extent_write_locked_range()
  btrfs: make extent_write_locked_range() to handle subpage writeback
    correctly

 fs/btrfs/extent_io.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

-- 
2.44.0