On Thu, Jan 16, 2020 at 08:21:48AM -0800, Christoph Hellwig wrote: > > @@ -2960,6 +2960,10 @@ xfs_read_agf( > > mp, tp, mp->m_ddev_targp, > > XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)), > > XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops); > > + if (error == -EAGAIN && (flags & XBF_TRYLOCK)) { > > Given that EAGAIN is only returned in the XBF_TRYLOCK case the check > for XBF_TRYLOCK should not be required. Ok. > > + *bpp = NULL; > > + return 0; > > Also we should make sure in the lowest layers to never return a > non-NULL bpp if returning an error to avoid this boilerplate code. <nod> At some point I was planning to audit the ALLOC_TRYLOCK cases to make sure that they can handle an EAGAIN, so we can get rid of this chunk entirely. > > - if (!bp) > > - return -ENOMEM; > > + error = xfs_buf_read_map(target, &map, 1, flags, &bp, ops); > > + if (error) > > + return error; > > error = bp->b_error; > > if (error) { > > xfs_buf_ioerror_alert(bp, __func__); > > The extra checking of bp->b_error shoudn't be required now. That almost > means we might have to move the xfs_buf_ioerror_alert into > xfs_buf_read_map. > > That also means xfs_buf_read can be turned into a simple inline > function again. Yeah, I'll add another patch to factor that out. --D