This patch sets dax device 'DAXDEV_SYNC' flag if all the target devices of device mapper support synchrononous DAX. If device mapper consists of both synchronous and asynchronous dax devices, we don't set 'DAXDEV_SYNC' flag.
Signed-off-by: Pankaj Gupta <pagu...@redhat.com> --- drivers/md/dm-table.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 350cf0451456..c5160d846fe6 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -890,10 +890,17 @@ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, start, len); } +static int device_synchronous(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + return dax_synchronous(dev->dax_dev); +} + bool dm_table_supports_dax(struct dm_table *t, int blocksize) { struct dm_target *ti; unsigned i; + bool dax_sync = true; /* Ensure that all targets support DAX. */ for (i = 0; i < dm_table_get_num_targets(t); i++) { @@ -906,7 +913,14 @@ bool dm_table_supports_dax(struct dm_table *t, int blocksize) !ti->type->iterate_devices(ti, device_supports_dax, &blocksize)) return false; + + /* Check devices support synchronous DAX */ + if (dax_sync && + !ti->type->iterate_devices(ti, device_synchronous, NULL)) + dax_sync = false; } + if (dax_sync) + set_dax_synchronous(t->md->dax_dev); return true; } -- 2.20.1 _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm