Re: [PATCH] Revert "Btrfs: race free update of commit root for ro snapshots"

[Filipe David Manana <fdmanana@gmail.com>]

On Wed, Oct 15, 2014 at 11:42 PM, john terragon <jterragon@gmail.com> wrote:
> Hi.
>
> I applied the patch to 3.17.1 but although I haven't seen any
> corrupted ro snapshot yet it's still impossible to do btrfs send. As
> soon as I start btrfs send I still get
>
> ERROR: send ioctl failed with -12: Cannot allocate memory
>
> even if I redirect btrfs send's output to a file (instead of involving
> btrfs receive)
>
> Maybe this time it's actually a btrfs-progs bug?

Not enough information to tell.

Is it a brand new fs? If not, is it a snapshot created after applying
the patch or before? Does a btrfsck reports any issues with the fs?
Is it an incremental (using -p <parent_snapshot>) or a full send? Do
you see any warning (traces, errors) in syslog (dmesg)?

Either an issue in send or, if it's an fs created/used with unpatched
3.17.0/1, it can be a side effect of the corruption.

thanks

>
> Thanks
> John



-- 
Filipe David Manana,

"Reasonable men adapt themselves to the world.
 Unreasonable men adapt the world to themselves.
 That's why all progress depends on unreasonable men."