tree 86c4b040a5325188562ef075c9256d32de6fdff7
parent 5afedf670caf30a2b5a52da96eb7eac7dee6a9c9
author Ming Lei <ming.lei@redhat.com> 1632364671 +0800
committer Jens Axboe <axboe@kernel.dk> 1632503218 -0600

block: hold ->invalidate_lock in blkdev_fallocate

When running ->fallocate(), blkdev_fallocate() should hold
mapping->invalidate_lock to prevent page cache from being accessed,
otherwise stale data may be read in page cache.

Without this patch, blktests block/009 fails sometimes. With this patch,
block/009 can pass always.

Also as Jan pointed out, no pages can be created in the discarded area
while you are holding the invalidate_lock, so remove the 2nd
truncate_bdev_range().

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210923023751.1441091-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>