On Thu, May 18 2023 at 6:33P -0400, Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx> wrote: > Introduce block request REQ_OP_PROVISION. The intent of this request > is to request underlying storage to preallocate disk space for the given > block range. Block devices that support this capability will export > a provision limit within their request queues. > > This patch also adds the capability to call fallocate() in mode 0 > on block devices, which will send REQ_OP_PROVISION to the block > device for the specified range, > > Signed-off-by: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx> > --- ... > diff --git a/block/blk-settings.c b/block/blk-settings.c > index 896b4654ab00..d303e6614c36 100644 > --- a/block/blk-settings.c > +++ b/block/blk-settings.c > @@ -59,6 +59,7 @@ void blk_set_default_limits(struct queue_limits *lim) > lim->zoned = BLK_ZONED_NONE; > lim->zone_write_granularity = 0; > lim->dma_alignment = 511; > + lim->max_provision_sectors = 0; > } > > /** > @@ -82,6 +83,7 @@ void blk_set_stacking_limits(struct queue_limits *lim) > lim->max_dev_sectors = UINT_MAX; > lim->max_write_zeroes_sectors = UINT_MAX; > lim->max_zone_append_sectors = UINT_MAX; > + lim->max_provision_sectors = UINT_MAX; > } > EXPORT_SYMBOL(blk_set_stacking_limits); > > @@ -578,6 +594,9 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, > t->max_segment_size = min_not_zero(t->max_segment_size, > b->max_segment_size); > > + t->max_provision_sectors = min_not_zero(t->max_provision_sectors, > + b->max_provision_sectors); > + This needs to use min() since max_provision_sectors also serves to indicate if the device supports REQ_OP_PROVISION. Otherwise, if I set max_provision_sectors to 0 on a dm thin-pool the blk_stack_limits() will ignore my having set it to 0 (to disable) and it'll remain as UINT_MAX (thanks to blk_set_default_limits). Mike
