| Message ID | 20180419185723.GA26938@bfoster.bfoster (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Apr 19, 2018 at 02:57:23PM -0400, Brian Foster wrote: > On Thu, Apr 19, 2018 at 10:25:48AM -0700, Darrick J. Wong wrote: > > On Thu, Apr 19, 2018 at 08:55:47AM -0400, Brian Foster wrote: > > > On Tue, Apr 17, 2018 at 07:40:20PM -0700, Darrick J. Wong wrote: > > > > From: Darrick J. Wong <darrick.wong@oracle.com> > > > > > > > > We've never cached buffers when reading or writing superblocks, so we > > > > need to change scrub to do likewise or risk screwing up the uncached sb > > > > buffer usage everywhere else. > > > > > > > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> > > > > --- > > > > > > Hmm, so this goes back to this[1] thread, right? > > > > Yep. > > > > > IIRC, we wanted to end up with an lru-bypassing uncached buffer lookup > > > mechanism to provide uncached behavior for resource-saving purposes > > > but without introducing serialization issues between multiple users of > > > uncached buffers. > > > > Right. > > > > > On a quick look back, growfs currently uses cached buffers for secondary > > > superblocks and the associated patch was looking to change that to > > > something like the above. Don't we have the same requirement here (since > > > growfs currently still uses cached buffers)? > > > > Correct, this patch is contingent on landing Dave's "tableise growfs" > > series that converts growfs to use uncached buffers for writing out the > > new secondary supers. If I manage to land Dave's growfs thing before > > repair then I'll keep this; if repair goes first I'll defer it to that > > series. > > > > Ok, though I'm not sure I see the need for the higher level series > dependency. Don't one of these patches just need to fold in a helper[1] > to set the lru reference appropriately and start to use it? Yes, that would work. :P Cheers, Dave.
On Fri, Apr 20, 2018 at 10:07:16AM +1000, Dave Chinner wrote: > On Thu, Apr 19, 2018 at 02:57:23PM -0400, Brian Foster wrote: > > On Thu, Apr 19, 2018 at 10:25:48AM -0700, Darrick J. Wong wrote: > > > On Thu, Apr 19, 2018 at 08:55:47AM -0400, Brian Foster wrote: > > > > On Tue, Apr 17, 2018 at 07:40:20PM -0700, Darrick J. Wong wrote: > > > > > From: Darrick J. Wong <darrick.wong@oracle.com> > > > > > > > > > > We've never cached buffers when reading or writing superblocks, so we > > > > > need to change scrub to do likewise or risk screwing up the uncached sb > > > > > buffer usage everywhere else. > > > > > > > > > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> > > > > > --- > > > > > > > > Hmm, so this goes back to this[1] thread, right? > > > > > > Yep. > > > > > > > IIRC, we wanted to end up with an lru-bypassing uncached buffer lookup > > > > mechanism to provide uncached behavior for resource-saving purposes > > > > but without introducing serialization issues between multiple users of > > > > uncached buffers. > > > > > > Right. > > > > > > > On a quick look back, growfs currently uses cached buffers for secondary > > > > superblocks and the associated patch was looking to change that to > > > > something like the above. Don't we have the same requirement here (since > > > > growfs currently still uses cached buffers)? > > > > > > Correct, this patch is contingent on landing Dave's "tableise growfs" > > > series that converts growfs to use uncached buffers for writing out the > > > new secondary supers. If I manage to land Dave's growfs thing before > > > repair then I'll keep this; if repair goes first I'll defer it to that > > > series. > > > > > > > Ok, though I'm not sure I see the need for the higher level series > > dependency. Don't one of these patches just need to fold in a helper[1] > > to set the lru reference appropriately and start to use it? > > Yes, that would work. :P Ok, I'll fold that into my patch and I'll fix things up depending on who wins the race. I changed the ASSERT to trip on agno == 0, btw. --D > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c index d9b94bd5f689..19ffe2819bb2 100644 --- a/fs/xfs/libxfs/xfs_sb.c +++ b/fs/xfs/libxfs/xfs_sb.c @@ -972,3 +972,24 @@ xfs_fs_geometry( return 0; } + +int +xfs_read_secondary_sb( + struct xfs_mount *mp, + struct xfs_trans *tp, + xfs_agnumber_t agno, + struct xfs_buf **bpp) +{ + struct xfs_buf *bp; + int error; + + ASSERT(agno != NULLAGNUMBER); + error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, + XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)), + XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops); + if (error) + return error; + xfs_buf_set_ref(bp, XFS_SSB_REF); + *bpp = bp; + return 0; +} diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h index d0b84da0cb1e..d23f33c02f64 100644 --- a/fs/xfs/libxfs/xfs_shared.h +++ b/fs/xfs/libxfs/xfs_shared.h @@ -127,6 +127,7 @@ void xfs_log_get_max_trans_res(struct xfs_mount *mp, #define XFS_ATTR_BTREE_REF 1 #define XFS_DQUOT_REF 1 #define XFS_REFC_BTREE_REF 1 +#define XFS_SSB_REF 0 /* * Flags for xfs_trans_ichgtime().