On Wed, 16 Mar 2011 16:30:22 -0400 Jeff Moyer <jmoyer@xxxxxxxxxx> wrote: > NeilBrown <neilb@xxxxxxx> writes: > > >> Synchronous notification of errors. If we don't try to write everything > >> back immediately after the size change, we don't see dirty pages in > >> zapped regions until the writeout/page cache management takes it into > >> its head to try to clean the pages. > >> > > > > So if you just want synchronous errors, I think you want: > > fsync_bdev() > > > > which calls sync_filesystem() if it can find a filesystem, else > > sync_blockdev(); (sync_filesystem itself calls sync_blockdev too). > > ... which deadlocks md. ;-) writeback_inodes_sb_nr is waiting for the > flusher thread to write back the dirty data. The flusher thread is > stuck in md_write_start, here: > > wait_event(mddev->sb_wait, > !test_bit(MD_CHANGE_PENDING, &mddev->flags)); > > This is after reverting your change, and replacing the flush_disk call > in check_disk_size_change with a call to fsync_bdev. I'm not familiar > enough with md to really suggest a way forward. Neil? That would be quite easy to avoid. Just call md_write_start() before revalidate_disk, and md_write_end() afterwards. You wouldn't have a 'bio' to pass in - but it is rather ugly requiring one anyway - I should fix that. For testing, just pass in NULL, and change if (bio_data_dir(bi) != WRITE) return; to if (bi && bio_data_dir(bi) != WRITE) return; NeilBrown -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
