[PATCH v2 0/7] exfat: fix valid_size handling and locking

[Chi Zhiling <chizhiling@163.com>]

From: Chi Zhiling <chizhiling@kylinos.cn>

valid_size marks the on-disk up-to-date (VDL) region of an exFAT file.
Data below it is valid; data at or above it is a hole that reads
zero-fill, so valid_size must be advanced in the window where the data
actually becomes valid.

Patches 1-3 fix the standalone bugs (append offset, truncate vs mmap
locking, dirtying of newly zeroed pages), patch 4 makes valid_size and
zeroed_size monotonic atomic counters as a prerequisite, and patches 5-7
advance valid_size under the folio lock and drop i_rwsem from
->page_mkwrite.

Link: https://lore.kernel.org/exfat/10029d6f-13cc-4d17-a2f9-b093a8339dde/T/#t

V1: https://lore.kernel.org/exfat/59056131-e3bd-4003-8c30-0a356cf0bd82@163.com/

Chi Zhiling (7):
  exfat: advance valid_size to EOF for append writes
  exfat: hold the invalidate lock while truncating
  exfat: dirty all new pages when extending valid_size
  exfat: make valid_size and zeroed_size atomic
  exfat: publish valid_size under the folio lock for buffered writes
  exfat: advance valid_size while zeroing new ranges
  exfat: drop i_rwsem from exfat_page_mkwrite

 fs/exfat/exfat_fs.h |  60 +++++++++++++++-
 fs/exfat/file.c     | 166 +++++++++++++++-----------------------------
 fs/exfat/inode.c    |  16 +++--
 fs/exfat/iomap.c    |  36 +++++++---
 fs/exfat/iomap.h    |   1 +
 fs/exfat/namei.c    |   4 +-
 6 files changed, 151 insertions(+), 132 deletions(-)

-- 
2.53.0