Re: [PATCH] USB: storage: add "no SYNCHRONIZE CACHE" quirk

2015-12-15 Thread Oliver Neukum
On Thu, 2015-12-03 at 13:36 -0500, Alan Stern wrote: > This is an old problem, but it was never resolved and it still affects > people (Bugzilla #89511). In short, there are USB-(S)ATA bridges that > claim to be write-back but don't support the SYNCHRONIZE CACHE > command. > This causes errors

Re: [PATCH] USB: storage: add "no SYNCHRONIZE CACHE" quirk

2015-12-15 Thread Alan Stern
On Tue, 15 Dec 2015, Oliver Neukum wrote: > On Thu, 2015-12-03 at 13:36 -0500, Alan Stern wrote: > > This is an old problem, but it was never resolved and it still affects > > people (Bugzilla #89511). In short, there are USB-(S)ATA bridges that > > claim to be write-back but don't support the

Re: [PATCH] USB: storage: add "no SYNCHRONIZE CACHE" quirk

2015-12-03 Thread Alan Stern
This is an old problem, but it was never resolved and it still affects people (Bugzilla #89511). In short, there are USB-(S)ATA bridges that claim to be write-back but don't support the SYNCHRONIZE CACHE command. This causes errors when filesystems try to flush data out to the disk. On Mon, 22

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-07-24 Thread Alan Stern
On Mon, 22 Jun 2015, James Bottomley wrote: On Mon, 2015-06-22 at 13:48 -0400, Alan Stern wrote: On Mon, 22 Jun 2015, James Bottomley wrote: On Mon, 2015-06-22 at 13:30 -0400, Alan Stern wrote: On Mon, 22 Jun 2015, James Bottomley wrote: I'm not sure I entirely like this:

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-26 Thread Stefan Richter
On Jun 22 James Bottomley wrote: On Mon, 2015-06-22 at 13:30 -0400, Alan Stern wrote: On Mon, 22 Jun 2015, James Bottomley wrote: Obviously, for a disk with a writeback cache that can't do flush, that window is much wider and the real solution should be to try to switch the cache to

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-26 Thread James Bottomley
On Fri, 2015-06-26 at 11:43 +0200, Stefan Richter wrote: On Jun 22 James Bottomley wrote: On Mon, 2015-06-22 at 13:30 -0400, Alan Stern wrote: On Mon, 22 Jun 2015, James Bottomley wrote: Obviously, for a disk with a writeback cache that can't do flush, that window is much wider and

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-26 Thread Stefan Richter
On Jun 26 James Bottomley wrote: On Fri, 2015-06-26 at 11:43 +0200, Stefan Richter wrote: On Jun 22 James Bottomley wrote: [...] Perhaps it might be wise to do this to every USB device ... for external devices, the small performance gain doesn't really make up for the potential data

RE: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-23 Thread David Laight
From: Of James Bottomley Sent: 22 June 2015 18:36 To: Alan Stern ... Obviously, for a disk with a writeback cache that can't do flush, that window is much wider and the real solution should be to try to switch the cache to write through. I agree. Doing the switch manually (by

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread Alan Stern
On Mon, 22 Jun 2015, James Bottomley wrote: I'm not sure I entirely like this: we are back again treating data corruption problems silently. However, I also believe treating a single flush failure as a critical filesystem error is also wrong: The data's all there correctly; all it does

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread James Bottomley
On Mon, 2015-06-22 at 13:30 -0400, Alan Stern wrote: On Mon, 22 Jun 2015, James Bottomley wrote: I'm not sure I entirely like this: we are back again treating data corruption problems silently. However, I also believe treating a single flush failure as a critical filesystem error is

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread James Bottomley
On Mon, 2015-06-22 at 10:55 -0400, Alan Stern wrote: Some USB mass-storage devices claim to have a write-back cache but don't support the SYNCHRONIZE CACHE command, which means there is no way to tell these devices to flush their caches out to permanent storage. Unfortunately, there is

[PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread Alan Stern
Some USB mass-storage devices claim to have a write-back cache but don't support the SYNCHRONIZE CACHE command, which means there is no way to tell these devices to flush their caches out to permanent storage. Unfortunately, there is nothing we can do about this. Until recently this deficiency

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread Markus Rathgeb
Maybe your patch will be acceptable, though. We'll have to hear from Markus and Matt. We'll probably have to take this to fsdevel as well ... they might have opinions about whether the FS wants to be informed about flush failure. So, it is okay to wait for the end of that discussion

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread Alan Stern
On Mon, 22 Jun 2015, Markus Rathgeb wrote: Maybe your patch will be acceptable, though. We'll have to hear from Markus and Matt. We'll probably have to take this to fsdevel as well ... they might have opinions about whether the FS wants to be informed about flush failure. So, it

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread James Bottomley
On Mon, 2015-06-22 at 13:48 -0400, Alan Stern wrote: On Mon, 22 Jun 2015, James Bottomley wrote: On Mon, 2015-06-22 at 13:30 -0400, Alan Stern wrote: On Mon, 22 Jun 2015, James Bottomley wrote: I'm not sure I entirely like this: we are back again treating data corruption

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread Markus Rathgeb
Please test it now. I'd like to know if it fixes your problem, regardless of how the discussion goes. Seems to be working, I also attached the kernel log. The flush failed will grow with disc activity (but that was to be expected). Jun 22 23:24:50 m3800 kernel: usb 1-3: new high-speed USB

Re: [PATCH] USB: storage: add no SYNCHRONIZE CACHE quirk

2015-06-22 Thread Alan Stern
On Mon, 22 Jun 2015, James Bottomley wrote: On Mon, 2015-06-22 at 13:30 -0400, Alan Stern wrote: On Mon, 22 Jun 2015, James Bottomley wrote: I'm not sure I entirely like this: we are back again treating data corruption problems silently. However, I also believe treating a