[PATCH 0/2] exfat: fix iomap mapping vs truncate race

[Youling Tang <youling.tang@linux.dev>]

From: Youling Tang <tangyouling@kylinos.cn>

This series fixes two related problems in the exfat iomap path.

Patch 1 fixes a race between iomap mapping and truncate: i_size was read
twice, and a shrink in between could make the mapping length negative,
which underflowed the cluster count.

Patch 2 fixes the handling of the EXFAT_EOF_CLUSTER sentinel returned by
exfat_map_cluster().  The iomap code used to convert it into a physical
address; it now maps the valid prefix of the range and reports only the
remaining part as a hole, matching the old buffer_head code.

Patch 2 relies on the non-negative length guaranteed by patch 1 for the
hole mapping.

Youling Tang (2):
  exfat: fix iomap mapping when writeback races with truncate
  exfat: don't map EXFAT_EOF_CLUSTER as a physical cluster

 fs/exfat/iomap.c | 38 ++++++++++++++++++++++++++++++++++----
 1 file changed, 34 insertions(+), 4 deletions(-)

-- 
2.43.0