[PATCH v4 0/2] Add FITRIM ioctl support for exFAT filesystem

[Hyeongseok Kim]

This is for adding FITRIM ioctl functionality to exFAT filesystem.
Firstly, because the fstrim is long operation, introduce bitmap_lock
to narrow the lock range to prevent read operation stall.
After that, add generic ioctl function and FITRIM handler.

Changelog
=========
v3->v4:
- Introduce bitmap_lock mutex to narrow the lock range for bitmap access
  and change to use bitmap_lock instead of s_lock in FITRIM handler to
  prevent read stall while ongoing fstrim.
- Minor code style fix

v2->v3:
- Remove unnecessary local variable
- Merge all changes to a single patch

v1->v2:
- Change variable declaration order as reverse tree style.
- Return -EOPNOTSUPP from sb_issue_discard() just as it is.
- Remove cond_resched() in while loop.
- Move ioctl related code into it's helper function.

Hyeongseok Kim (2):
  exfat: introduce bitmap_lock for cluster bitmap access
  exfat: add support ioctl and FITRIM function

 fs/exfat/balloc.c   | 80 +++++++++++++++++++++++++++++++++++++++++++++
 fs/exfat/dir.c      |  5 +++
 fs/exfat/exfat_fs.h |  5 +++
 fs/exfat/fatent.c   | 37 ++++++++++++++++-----
 fs/exfat/file.c     | 53 ++++++++++++++++++++++++++++++
 fs/exfat/super.c    |  1 +
 6 files changed, 173 insertions(+), 8 deletions(-)

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2.27.0.83.g0313f36