David, There are two variants of SB read, one using the device cache [1] and the other buffer head [2]. [1] btrfs_read_disk_super() [2] btrfs_read_dev_super() Patch, 6f60cbd3ae442cb35861bb522f388db123d42ec1 (btrfs: access superblock via pagecache in scan_one_device) Embraced device caches to avoid blocksize set and thus avoid device drop cache. But however its in the context of starting up with a new mount and in practice, would it really matter if the device cache is dropped in the context of mount, we any way drop it when the device is successfully mounted though. I don't understand the actual problem here. Further [2] is still using buffer head, which works very well for us in this context, any idea if there is any suggestion to move it to newer bio read instead ? Thanks, Anand -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
