For BIO based DM, some targets aren't ready for dealing with bigger incoming bio than 1Mbyte, such as crypt and log write targets.
Signed-off-by: Ming Lei <tom.leim...@gmail.com> --- drivers/md/dm.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ef7bf1dd6900..ce454c6c1a4e 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -899,7 +899,16 @@ int dm_set_target_max_io_len(struct dm_target *ti, sector_t len) return -EINVAL; } - ti->max_io_len = (uint32_t) len; + /* + * BIO based queue uses its own splitting. When multipage bvecs + * is switched on, size of the incoming bio may be too big to + * be handled in some targets, such as crypt and log write. + * + * When these targets are ready for the big bio, we can remove + * the limit. + */ + ti->max_io_len = min_t(uint32_t, len, + BIO_SP_MAX_SECTORS << SECTOR_SHIFT); return 0; } -- 2.7.4