diff options
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 4817ef1206a9..ee86cc60d4b8 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1968,6 +1968,15 @@ static void dm_split_and_process_bio(struct mapped_device *md, /* Only support nowait for normal IO */ if (unlikely(bio->bi_opf & REQ_NOWAIT) && !is_abnormal) { + /* + * Don't support NOWAIT for FLUSH because it may allocate + * multiple bios and there's no easy way how to undo the + * allocations. + */ + if (bio->bi_opf & REQ_PREFLUSH) { + bio_wouldblock_error(bio); + return; + } io = alloc_io(md, bio, GFP_NOWAIT); if (unlikely(!io)) { /* Unable to do anything without dm_io. */ |