This patchset avoids transaction reservation recursion by reintroducing
the discarded PF_FSTRANS in a new way, suggested by Dave. In this new 
implementation, four new helpers are introduced, which are 
xfs_trans_context_{set, clear, update} and fstrans_context_active,
suggested by Dave. And re-using the task->journal_info to indicates
whehter the task is in fstrans or not, suggested by Willy

Patch #1 is picked from Willy's patchset "Overhaul memalloc_no*"[1]

[1] https://lore.kernel.org/linux-mm/20200625113122.7540-1-willy@infradead.org/ (local)

v5:
- pick one of Willy's patch
- introduce four new helpers, per Dave

v4:
- retitle from "xfs: introduce task->in_fstrans for transaction reservation recursion protection"
- reuse current->journal_info, per Willy

Matthew Wilcox (Oracle) (1):
  mm: Add become_kswapd and restore_kswapd

Yafang Shao (1):
  xfs: avoid transaction reservation recursion

 fs/iomap/buffered-io.c    |  4 ++--
 fs/xfs/libxfs/xfs_btree.c | 14 ++++++++------
 fs/xfs/xfs_aops.c         |  5 +++--
 fs/xfs/xfs_linux.h        |  4 ----
 fs/xfs/xfs_trans.c        | 19 +++++++++----------
 fs/xfs/xfs_trans.h        | 23 +++++++++++++++++++++++
 include/linux/iomap.h     |  7 +++++++
 include/linux/sched/mm.h  | 28 ++++++++++++++++++++++++++++
 mm/vmscan.c               | 16 +---------------
 9 files changed, 81 insertions(+), 39 deletions(-)

-- 
2.18.1