[PATCH v2 0/6] smb/client: fix emulated insert/collapse range issues

[Huiwen He <huiwen.he@linux.dev>]

From: Huiwen He <hehuiwen@kylinos.cn>

This series fixes the SMB3 FALLOC_FL_INSERT_RANGE and
FALLOC_FL_COLLAPSE_RANGE emulation.

Patch 1 validates the new EOF for insert range, which previously allowed
RLIMIT_FSIZE to be bypassed.

Patch 2 validates the new EOF for zero range when it extends the file.

Patch 3 marks the file sparse before emulating insert range so the
inserted range becomes a real hole, fixing xfstests generic/064 against
Samba and ksmbd.

Patch 4 fixes data corruption in emulated insert range by copying
overlapping ranges from EOF backwards.

Patch 5 fixes integer truncation when the collapse-range copy exceeds
INT_MAX bytes.

Patch 6 fixes stale page cache after the range emulation, where reads
returned zeroes instead of the shifted data.

Changes in v2:

- update patch3 to propagate SET_SPARSE fails.
- Add patch2 and patch4-6.
 
Link to v1:
https://lore.kernel.org/linux-cifs/20260813132136.366532-1-huiwen.he@linux.dev/

Thanks,
Huiwen

Huiwen He (6):
  smb/client: validate new EOF for insert range
  smb/client: validate new EOF for zero range
  smb/client: mark file sparse before emulating insert range
  smb/client: fix data corruption in emulated insert range
  smb/client: fix integer truncation in collapse range
  smb/client: fix stale page cache in insert/collapse range

 fs/smb/client/smb2ops.c | 202 +++++++++++++++++++++++++++++++++-------
 1 file changed, 168 insertions(+), 34 deletions(-)

-- 
2.43.0