On Mon, Feb 04, 2019 at 02:24:51PM -0500, Brian Foster wrote:
> On Mon, Feb 04, 2019 at 09:59:14AM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> >
> > Track the number of unlinked inodes in each AG so that we can use these
> > decisions to throttle inactivations when the unlinked list gets long.
> >
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > ---
>
> I'm a little confused where we're at with this one given the discussion
> on the previous version. We've dropped the locking, but left the
> tracking in place. Are we just relying on holding the agi in the
> iunlink/iunlink_remove cases?
Yes.
> If so, that seems reasonable to me but the
> commit log should probably have a sentence or two on the serialization
> rules. The commit log could also use an update to describe how this
> value is actually used in this patch (as an unmount time check) as
> opposed to some apparent throttling functionality that isn't a part of
> this series.
I will improve the comments in the structure definition and update the
commit message.
--D
> Brian
>
> > fs/xfs/xfs_inode.c | 35 ++++++++++++++++++++++++-----------
> > fs/xfs/xfs_log_recover.c | 6 ++++++
> > fs/xfs/xfs_mount.c | 2 ++
> > fs/xfs/xfs_mount.h | 3 +++
> > 4 files changed, 35 insertions(+), 11 deletions(-)
> >
> >
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > index 2367cdfcd90b..435901c7c674 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -1900,6 +1900,7 @@ xfs_iunlink(
> > struct xfs_dinode *dip;
> > struct xfs_buf *agibp;
> > struct xfs_buf *ibp;
> > + struct xfs_perag *pag;
> > xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
> > xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
> > short bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
> > @@ -1907,11 +1908,12 @@ xfs_iunlink(
> > int error;
> >
> > ASSERT(VFS_I(ip)->i_mode != 0);
> > + pag = xfs_perag_get(mp, agno);
> >
> > /* Get the agi buffer first. It ensures lock ordering on the list. */
> > error = xfs_read_agi(mp, tp, agno, &agibp);
> > if (error)
> > - return error;
> > + goto out;
> > agi = XFS_BUF_TO_AGI(agibp);
> >
> > /*
> > @@ -1931,7 +1933,7 @@ xfs_iunlink(
> > error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
> > 0, 0);
> > if (error)
> > - return error;
> > + goto out;
> >
> > ASSERT(dip->di_next_unlinked == cpu_to_be32(NULLAGINO));
> > dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
> > @@ -1956,7 +1958,10 @@ xfs_iunlink(
> > (sizeof(xfs_agino_t) * bucket_index);
> > xfs_trans_log_buf(tp, agibp, offset,
> > (offset + sizeof(xfs_agino_t) - 1));
> > - return 0;
> > + pag->pagi_unlinked_count++;
> > +out:
> > + xfs_perag_put(pag);
> > + return error;
> > }
> >
> > /*
> > @@ -1974,6 +1979,7 @@ xfs_iunlink_remove(
> > struct xfs_buf *ibp;
> > struct xfs_buf *last_ibp;
> > struct xfs_dinode *last_dip = NULL;
> > + struct xfs_perag *pag;
> > xfs_ino_t next_ino;
> > xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
> > xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
> > @@ -1983,10 +1989,12 @@ xfs_iunlink_remove(
> > int last_offset = 0;
> > int error;
> >
> > + pag = xfs_perag_get(mp, agno);
> > +
> > /* Get the agi buffer first. It ensures lock ordering on the list. */
> > error = xfs_read_agi(mp, tp, agno, &agibp);
> > if (error)
> > - return error;
> > + goto out;
> > agi = XFS_BUF_TO_AGI(agibp);
> >
> > /*
> > @@ -1997,7 +2005,8 @@ xfs_iunlink_remove(
> > be32_to_cpu(agi->agi_unlinked[bucket_index]))) {
> > XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
> > agi, sizeof(*agi));
> > - return -EFSCORRUPTED;
> > + error = -EFSCORRUPTED;
> > + goto out;
> > }
> >
> > if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
> > @@ -2013,7 +2022,7 @@ xfs_iunlink_remove(
> > if (error) {
> > xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
> > __func__, error);
> > - return error;
> > + goto out;
> > }
> > next_agino = be32_to_cpu(dip->di_next_unlinked);
> > ASSERT(next_agino != 0);
> > @@ -2062,7 +2071,7 @@ xfs_iunlink_remove(
> > xfs_warn(mp,
> > "%s: xfs_imap returned error %d.",
> > __func__, error);
> > - return error;
> > + goto out;
> > }
> >
> > error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,
> > @@ -2071,7 +2080,7 @@ xfs_iunlink_remove(
> > xfs_warn(mp,
> > "%s: xfs_imap_to_bp returned error %d.",
> > __func__, error);
> > - return error;
> > + goto out;
> > }
> >
> > last_offset = imap.im_boffset;
> > @@ -2080,7 +2089,8 @@ xfs_iunlink_remove(
> > XFS_CORRUPTION_ERROR(__func__,
> > XFS_ERRLEVEL_LOW, mp,
> > last_dip, sizeof(*last_dip));
> > - return -EFSCORRUPTED;
> > + error = -EFSCORRUPTED;
> > + goto out;
> > }
> > }
> >
> > @@ -2093,7 +2103,7 @@ xfs_iunlink_remove(
> > if (error) {
> > xfs_warn(mp, "%s: xfs_imap_to_bp(2) returned error %d.",
> > __func__, error);
> > - return error;
> > + goto out;
> > }
> > next_agino = be32_to_cpu(dip->di_next_unlinked);
> > ASSERT(next_agino != 0);
> > @@ -2128,7 +2138,10 @@ xfs_iunlink_remove(
> > (offset + sizeof(xfs_agino_t) - 1));
> > xfs_inobp_check(mp, last_ibp);
> > }
> > - return 0;
> > + pag->pagi_unlinked_count--;
> > +out:
> > + xfs_perag_put(pag);
> > + return error;
> > }
> >
> > /*
> > diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> > index ff9a27834c50..c634fbfea4a8 100644
> > --- a/fs/xfs/xfs_log_recover.c
> > +++ b/fs/xfs/xfs_log_recover.c
> > @@ -5054,6 +5054,7 @@ xlog_recover_process_one_iunlink(
> > struct xfs_buf *ibp;
> > struct xfs_dinode *dip;
> > struct xfs_inode *ip;
> > + struct xfs_perag *pag;
> > xfs_ino_t ino;
> > int error;
> >
> > @@ -5077,6 +5078,11 @@ xlog_recover_process_one_iunlink(
> > agino = be32_to_cpu(dip->di_next_unlinked);
> > xfs_buf_relse(ibp);
> >
> > + /* Make sure the in-core data knows about this unlinked inode. */
> > + pag = xfs_perag_get(mp, agno);
> > + pag->pagi_unlinked_count++;
> > + xfs_perag_put(pag);
> > +
> > /*
> > * Prevent any DMAPI event from being sent when the reference on
> > * the inode is dropped.
> > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> > index 10be706ec72e..6ca92a71c233 100644
> > --- a/fs/xfs/xfs_mount.c
> > +++ b/fs/xfs/xfs_mount.c
> > @@ -149,6 +149,8 @@ xfs_free_perag(
> > spin_unlock(&mp->m_perag_lock);
> > ASSERT(pag);
> > ASSERT(atomic_read(&pag->pag_ref) == 0);
> > + ASSERT(pag->pagi_unlinked_count == 0 ||
> > + XFS_FORCED_SHUTDOWN(mp));
> > xfs_buf_hash_destroy(pag);
> > mutex_destroy(&pag->pag_ici_reclaim_lock);
> > call_rcu(&pag->rcu_head, __xfs_free_perag);
> > diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> > index e344b1dfde63..169069a01f3c 100644
> > --- a/fs/xfs/xfs_mount.h
> > +++ b/fs/xfs/xfs_mount.h
> > @@ -388,6 +388,9 @@ typedef struct xfs_perag {
> >
> > /* reference count */
> > uint8_t pagf_refcount_level;
> > +
> > + /* unlinked inode info; lock AGI to access */
> > + unsigned int pagi_unlinked_count;
> > } xfs_perag_t;
> >
> > static inline struct xfs_ag_resv *
> >
