[PATCH] Btrfs: disable FUA if mounted with nobarrier

2017-12-05 Thread Omar Sandoval
From: Omar Sandoval I was seeing disk flushes still happening when I mounted a Btrfs filesystem with nobarrier for testing. This is because we use FUA to write out the first super block, and on devices without FUA support, the block layer translates FUA to a flush. Even on devices supporting true

Re: [PATCH] Btrfs: disable FUA if mounted with nobarrier

2017-12-05 Thread Qu Wenruo
On 2017年12月06日 14:54, Omar Sandoval wrote: > From: Omar Sandoval > > I was seeing disk flushes still happening when I mounted a Btrfs > filesystem with nobarrier for testing. This is because we use FUA to > write out the first super block, and on devices without FUA support, the > block layer t

Re: [PATCH] Btrfs: disable FUA if mounted with nobarrier

2017-12-06 Thread David Sterba
On Tue, Dec 05, 2017 at 10:54:02PM -0800, Omar Sandoval wrote: > From: Omar Sandoval > > I was seeing disk flushes still happening when I mounted a Btrfs > filesystem with nobarrier for testing. This is because we use FUA to > write out the first super block, and on devices without FUA support, t