On Sat, Feb 08, 2025 at 11:12:57AM +0800, Zhang Yi wrote: > On 2025/2/8 6:14, Benjamin Marzinski wrote: > > On Wed, Jan 15, 2025 at 07:46:33PM +0800, Zhang Yi wrote: > >> From: Zhang Yi <yi.zhang@xxxxxxxxxx> > >> > >> Set the BLK_FEAT_WRITE_ZEROES_UNMAP feature on stacking queue limits by > >> default. This feature shall be disabled if any underlying device does > >> not support it. > >> > >> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx> > >> --- > >> drivers/md/dm-table.c | 3 ++- > >> 1 file changed, 2 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c > >> index bd8b796ae683..58cce31bcc1e 100644 > >> --- a/drivers/md/dm-table.c > >> +++ b/drivers/md/dm-table.c > >> @@ -598,7 +598,8 @@ int dm_split_args(int *argc, char ***argvp, char *input) > >> static void dm_set_stacking_limits(struct queue_limits *limits) > >> { > >> blk_set_stacking_limits(limits); > >> - limits->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL; > >> + limits->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL | > >> + BLK_FEAT_WRITE_ZEROES_UNMAP; > >> } > >> > > > > dm_table_set_restrictions() can set limits->max_write_zeroes_sectors to > > 0, and it's called after dm_calculate_queue_limits(), which calls > > blk_stack_limits(). Just to avoid having the BLK_FEAT_WRITE_ZEROES_UNMAP > > still set while a device's max_write_zeroes_sectors is 0, it seems like > > you would want to clear it as well if dm_table_set_restrictions() sets > > limits->max_write_zeroes_sectors to 0. > > > > Hi, Ben! > > Yeah, right. Thanks for pointing this out, and I also checked other > instances in dm where max_write_zeroes_sectors is set to 0, and it seems > we should also clear BLK_FEAT_WRITE_ZEROES_UNMAP in > disable_write_zeroes() as well. Yep. Makes sense. Thanks -Ben > > Thanks, > Yi.