block: Hold invalidate_lock in BLKDISCARD ioctl

When BLKDISCARD ioctl and data read race, the data read leaves stale
page cache. To avoid the stale page cache, hold invalidate_lock of the
block device file mapping. The stale page cache is observed when
blktests test case block/009 is repeated hundreds of times.

This patch can be applied back to the stable kernel version v5.15.y
with slight patch edit. Rework is required for older stable kernels.

Fixes: 351499a172c0 ("block: Invalidate cache on discard v2")
Signed-off-by: Shin'ichiro Kawasaki <[email protected]>
Cc: [email protected] # v5.15
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions