Re: [PATCH] Btrfs: skip commit transaction if we don't have enough pinned bytes

[Liu Bo <bo.li.liu@oracle.com>]

On Thu, May 25, 2017 at 06:50:48PM +0200, David Sterba wrote:
> On Tue, May 23, 2017 at 12:06:40PM +0300, Nikolay Borisov wrote:
> > 
> > 
> > On 19.05.2017 20:39, Liu Bo wrote:
> > > We commit transaction in order to reclaim space from pinned bytes because
> > > it could process delayed refs, and in may_commit_transaction(), we check
> > > first if pinned bytes are enough for the required space, we then check if
> > > that plus bytes reserved for delayed insert are enough for the required
> > > space.
> > > 
> > > This changes the code to the above logic.
> > > 
> > > Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
> > 
> > Please add:
> > Fixes: b150a4f10d87 ("Btrfs: use a percpu to keep track of possibly
> > pinned bytes")
> > 
> > > ---
> > >  fs/btrfs/extent-tree.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> > > index e390451c72e6..bded1ddd1bb6 100644
> > > --- a/fs/btrfs/extent-tree.c
> > > +++ b/fs/btrfs/extent-tree.c
> > > @@ -4837,7 +4837,7 @@ static int may_commit_transaction(struct btrfs_fs_info *fs_info,
> > >  
> > >  	spin_lock(&delayed_rsv->lock);
> > >  	if (percpu_counter_compare(&space_info->total_bytes_pinned,
> > > -				   bytes - delayed_rsv->size) >= 0) {
> > > +				   bytes - delayed_rsv->size) < 0) {
> > >  		spin_unlock(&delayed_rsv->lock);
> > >  		return -ENOSPC;
> > >  	}
> > > 
> > 
> > With the minor nit above:
> > 
> > Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> > Tested-by: Nikolay Borisov <nborisov@suse.com>
> 
> Patch applied with updated tags.

Thank you for that!

-liubo