On Wed, Jan 26, 2022 at 11:58:30AM +0800, Ming Lei wrote: > If backing file's filesystem has implemented ->fallocate(), we think the > loop device can support discard, then pass sb->s_blocksize as > discard_granularity. However, some underlying FS, such as overlayfs, > doesn't set sb->s_blocksize, and causes discard_granularity to be set as > zero, then the warning in __blkdev_issue_discard() is triggered. > > Christoph suggested to pass kstatfs.f_bsize as discard granularity, and > this way is fine because kstatfs.f_bsize means 'Optimal transfer block > size', which still matches with definition of discard granularity. > > So fix the issue by setting discard_granularity as kstatfs.f_bsize if it > is available, otherwise claims discard isn't supported. > > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> > Reported-by: Pei Zhang <pezhang@xxxxxxxxxx> > Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> > --- > V3: > - following Christoph's suggestion to not claim discard support if > vfs_statfs() fails Hi Jens, Any chance to merge it to v5.17? Thanks, Ming
