On Wed, Jan 4, 2017 at 12:43 AM, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > On Tue, Dec 27 2016 at 10:56am -0500, > Ming Lei <tom.leiming@xxxxxxxxx> wrote: > >> For BIO based DM, some targets aren't ready for dealing with >> bigger incoming bio than 1Mbyte, such as crypt target. >> >> Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx> >> --- >> 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 3086da5664f3..6139bf7623f7 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. >> + * >> + * When these targets are ready for the big bio, we can remove >> + * the limit. >> + */ >> + ti->max_io_len = min_t(uint32_t, len, >> + (BIO_MAX_PAGES * PAGE_SIZE)); >> >> return 0; >> } >> -- >> 2.7.4 > > dm_set_target_max_io_len() is already meant to be called by the .ctr > hook for each DM target. So why not just have the dm-crypt target (and > other targets if needed) pass your reduced $len? > > That way only targets that need to be fixed (e.g. dm-crypt) impose this > limit. Looks better way, and I will do it in V2. Thanks, Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
