xfs: connect refcount adjust functions to upper layers
Plumb in the upper level interface to schedule and finish deferred
refcount operations via the deferred ops mechanism.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c
index f522fe1..4a31a7c 100644
--- a/fs/xfs/libxfs/xfs_refcount.c
+++ b/fs/xfs/libxfs/xfs_refcount.c
@@ -989,3 +989,177 @@
error, _RET_IP_);
return error;
}
+
+/* Clean up after calling xfs_refcount_finish_one. */
+void
+xfs_refcount_finish_one_cleanup(
+ struct xfs_trans *tp,
+ struct xfs_btree_cur *rcur,
+ int error)
+{
+ struct xfs_buf *agbp;
+
+ if (rcur == NULL)
+ return;
+ agbp = rcur->bc_private.a.agbp;
+ xfs_btree_del_cursor(rcur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+ if (error)
+ xfs_trans_brelse(tp, agbp);
+}
+
+/*
+ * Process one of the deferred refcount operations. We pass back the
+ * btree cursor to maintain our lock on the btree between calls.
+ * This saves time and eliminates a buffer deadlock between the
+ * superblock and the AGF because we'll always grab them in the same
+ * order.
+ */
+int
+xfs_refcount_finish_one(
+ struct xfs_trans *tp,
+ struct xfs_defer_ops *dfops,
+ enum xfs_refcount_intent_type type,
+ xfs_fsblock_t startblock,
+ xfs_extlen_t blockcount,
+ xfs_fsblock_t *new_fsb,
+ xfs_extlen_t *new_len,
+ struct xfs_btree_cur **pcur)
+{
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_btree_cur *rcur;
+ struct xfs_buf *agbp = NULL;
+ int error = 0;
+ xfs_agnumber_t agno;
+ xfs_agblock_t bno;
+ xfs_agblock_t new_agbno;
+ unsigned long nr_ops = 0;
+ int shape_changes = 0;
+
+ agno = XFS_FSB_TO_AGNO(mp, startblock);
+ ASSERT(agno != NULLAGNUMBER);
+ bno = XFS_FSB_TO_AGBNO(mp, startblock);
+
+ trace_xfs_refcount_deferred(mp, XFS_FSB_TO_AGNO(mp, startblock),
+ type, XFS_FSB_TO_AGBNO(mp, startblock),
+ blockcount);
+
+ if (XFS_TEST_ERROR(false, mp,
+ XFS_ERRTAG_REFCOUNT_FINISH_ONE,
+ XFS_RANDOM_REFCOUNT_FINISH_ONE))
+ return -EIO;
+
+ /*
+ * If we haven't gotten a cursor or the cursor AG doesn't match
+ * the startblock, get one now.
+ */
+ rcur = *pcur;
+ if (rcur != NULL && rcur->bc_private.a.agno != agno) {
+ nr_ops = rcur->bc_private.a.priv.refc.nr_ops;
+ shape_changes = rcur->bc_private.a.priv.refc.shape_changes;
+ xfs_refcount_finish_one_cleanup(tp, rcur, 0);
+ rcur = NULL;
+ *pcur = NULL;
+ }
+ if (rcur == NULL) {
+ error = xfs_alloc_read_agf(tp->t_mountp, tp, agno,
+ XFS_ALLOC_FLAG_FREEING, &agbp);
+ if (error)
+ return error;
+ if (!agbp)
+ return -EFSCORRUPTED;
+
+ rcur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno, dfops);
+ if (!rcur) {
+ error = -ENOMEM;
+ goto out_cur;
+ }
+ rcur->bc_private.a.priv.refc.nr_ops = nr_ops;
+ rcur->bc_private.a.priv.refc.shape_changes = shape_changes;
+ }
+ *pcur = rcur;
+
+ switch (type) {
+ case XFS_REFCOUNT_INCREASE:
+ error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno,
+ new_len, XFS_REFCOUNT_ADJUST_INCREASE, dfops, NULL);
+ *new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno);
+ break;
+ case XFS_REFCOUNT_DECREASE:
+ error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno,
+ new_len, XFS_REFCOUNT_ADJUST_DECREASE, dfops, NULL);
+ *new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno);
+ break;
+ default:
+ ASSERT(0);
+ error = -EFSCORRUPTED;
+ }
+ if (!error && *new_len > 0)
+ trace_xfs_refcount_finish_one_leftover(mp, agno, type,
+ bno, blockcount, new_agbno, *new_len);
+ return error;
+
+out_cur:
+ xfs_trans_brelse(tp, agbp);
+
+ return error;
+}
+
+/*
+ * Record a refcount intent for later processing.
+ */
+static int
+__xfs_refcount_add(
+ struct xfs_mount *mp,
+ struct xfs_defer_ops *dfops,
+ enum xfs_refcount_intent_type type,
+ xfs_fsblock_t startblock,
+ xfs_extlen_t blockcount)
+{
+ struct xfs_refcount_intent *ri;
+
+ trace_xfs_refcount_defer(mp, XFS_FSB_TO_AGNO(mp, startblock),
+ type, XFS_FSB_TO_AGBNO(mp, startblock),
+ blockcount);
+
+ ri = kmem_alloc(sizeof(struct xfs_refcount_intent),
+ KM_SLEEP | KM_NOFS);
+ INIT_LIST_HEAD(&ri->ri_list);
+ ri->ri_type = type;
+ ri->ri_startblock = startblock;
+ ri->ri_blockcount = blockcount;
+
+ xfs_defer_add(dfops, XFS_DEFER_OPS_TYPE_REFCOUNT, &ri->ri_list);
+ return 0;
+}
+
+/*
+ * Increase the reference count of the blocks backing a file's extent.
+ */
+int
+xfs_refcount_increase_extent(
+ struct xfs_mount *mp,
+ struct xfs_defer_ops *dfops,
+ struct xfs_bmbt_irec *PREV)
+{
+ if (!xfs_sb_version_hasreflink(&mp->m_sb))
+ return 0;
+
+ return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_INCREASE,
+ PREV->br_startblock, PREV->br_blockcount);
+}
+
+/*
+ * Decrease the reference count of the blocks backing a file's extent.
+ */
+int
+xfs_refcount_decrease_extent(
+ struct xfs_mount *mp,
+ struct xfs_defer_ops *dfops,
+ struct xfs_bmbt_irec *PREV)
+{
+ if (!xfs_sb_version_hasreflink(&mp->m_sb))
+ return 0;
+
+ return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_DECREASE,
+ PREV->br_startblock, PREV->br_blockcount);
+}