Hello all, We are running bcache in 4.1.49 with both the cache and backing device having 4k blocks. The disk stack is DRBD->dm-thin->bcache->[sdc->sdb] Where sdc is the cache. Sometimes we get errors like the following: [432015.934869] block drbd8065: Began resync as SyncTarget (will sync 880 KB [220 bits set]). [432015.949469] sd 0:0:0:1: [sdb] Unaligned block number requested: sector_size=4096, block=15724561783, blk_rq=9 [432015.950347] sd 0:0:0:2: [sdc] Unaligned block number requested: sector_size=4096, block=353041040, blk_rq=7 [432015.951146] bcache: bch_count_io_errors() dm-6: IO error on reading from cache, recovering [432015.952015] block drbd8065: read: error=-5 s=19281488s [432015.952866] block drbd8065: Local IO failed in drbd_endio_read_sec_final. [432015.953777] sd 0:0:0:2: [sdc] Unaligned block number requested: sector_size=4096, block=387084784, blk_rq=7 [432015.954710] bcache: bch_count_io_errors() dm-6: IO error on reading from cache, recovering [432015.959037] sd 0:0:0:1: [sdb] Unaligned block number requested: sector_size=4096, block=15725385535, blk_rq=1 [432015.959938] block drbd8065: read: error=-5 s=19391384s [432015.960862] block drbd8065: Local IO failed in drbd_endio_read_sec_final. Note that 15724561783 is not divisible by 8, thus it is unaligned to 4k blocks. Does anyone know if the bcache code is enforcing correct alignment? Is there any way that bcache could introduce misalignment? We ran blockdev --getbsz and --getpbsz all the way down the stack and everything reports 4k. Thank you for your help! -- Eric Wheeler -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
