xfs: log rmap intent items
Provide a mechanism for higher levels to create RUI/RUD items, submit
them to the log, and a stub function to deal with recovered RUI items.
These parts will be connected to the rmapbt in a later patch.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_trans_rmap.c b/fs/xfs/xfs_trans_rmap.c
new file mode 100644
index 0000000..e3a5172
--- /dev/null
+++ b/fs/xfs/xfs_trans_rmap.c
@@ -0,0 +1,205 @@
+/*
+ * Copyright (C) 2016 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_trans.h"
+#include "xfs_trans_priv.h"
+#include "xfs_rmap_item.h"
+#include "xfs_alloc.h"
+#include "xfs_rmap.h"
+
+/*
+ * This routine is called to allocate an "rmap update intent"
+ * log item that will hold nextents worth of extents. The
+ * caller must use all nextents extents, because we are not
+ * flexible about this at all.
+ */
+struct xfs_rui_log_item *
+xfs_trans_get_rui(
+ struct xfs_trans *tp,
+ uint nextents)
+{
+ struct xfs_rui_log_item *ruip;
+
+ ASSERT(tp != NULL);
+ ASSERT(nextents > 0);
+
+ ruip = xfs_rui_init(tp->t_mountp, nextents);
+ ASSERT(ruip != NULL);
+
+ /*
+ * Get a log_item_desc to point at the new item.
+ */
+ xfs_trans_add_item(tp, &ruip->rui_item);
+ return ruip;
+}
+
+/* Set the map extent flags for this reverse mapping. */
+static void
+xfs_trans_set_rmap_flags(
+ struct xfs_map_extent *rmap,
+ enum xfs_rmap_intent_type type,
+ int whichfork,
+ xfs_exntst_t state)
+{
+ rmap->me_flags = 0;
+ if (state == XFS_EXT_UNWRITTEN)
+ rmap->me_flags |= XFS_RMAP_EXTENT_UNWRITTEN;
+ if (whichfork == XFS_ATTR_FORK)
+ rmap->me_flags |= XFS_RMAP_EXTENT_ATTR_FORK;
+ switch (type) {
+ case XFS_RMAP_MAP:
+ rmap->me_flags |= XFS_RMAP_EXTENT_MAP;
+ break;
+ case XFS_RMAP_UNMAP:
+ rmap->me_flags |= XFS_RMAP_EXTENT_UNMAP;
+ break;
+ case XFS_RMAP_CONVERT:
+ rmap->me_flags |= XFS_RMAP_EXTENT_CONVERT;
+ break;
+ case XFS_RMAP_ALLOC:
+ rmap->me_flags |= XFS_RMAP_EXTENT_ALLOC;
+ break;
+ case XFS_RMAP_FREE:
+ rmap->me_flags |= XFS_RMAP_EXTENT_FREE;
+ break;
+ default:
+ ASSERT(0);
+ }
+}
+
+/*
+ * This routine is called to indicate that the described reverse
+ * mapping is to be logged as needing to be updated. It should be
+ * called once for each mapping.
+ */
+void
+xfs_trans_log_start_rmap_update(
+ struct xfs_trans *tp,
+ struct xfs_rui_log_item *ruip,
+ enum xfs_rmap_intent_type type,
+ __uint64_t owner,
+ int whichfork,
+ xfs_fileoff_t startoff,
+ xfs_fsblock_t startblock,
+ xfs_filblks_t blockcount,
+ xfs_exntst_t state)
+{
+ uint next_extent;
+ struct xfs_map_extent *rmap;
+
+ tp->t_flags |= XFS_TRANS_DIRTY;
+ ruip->rui_item.li_desc->lid_flags |= XFS_LID_DIRTY;
+
+ /*
+ * atomic_inc_return gives us the value after the increment;
+ * we want to use it as an array index so we need to subtract 1 from
+ * it.
+ */
+ next_extent = atomic_inc_return(&ruip->rui_next_extent) - 1;
+ ASSERT(next_extent < ruip->rui_format.rui_nextents);
+ rmap = &(ruip->rui_format.rui_extents[next_extent]);
+ rmap->me_owner = owner;
+ rmap->me_startblock = startblock;
+ rmap->me_startoff = startoff;
+ rmap->me_len = blockcount;
+ xfs_trans_set_rmap_flags(rmap, type, whichfork, state);
+}
+
+
+/*
+ * This routine is called to allocate an "rmap update done"
+ * log item that will hold nextents worth of extents. The
+ * caller must use all nextents extents, because we are not
+ * flexible about this at all.
+ */
+struct xfs_rud_log_item *
+xfs_trans_get_rud(
+ struct xfs_trans *tp,
+ struct xfs_rui_log_item *ruip,
+ uint nextents)
+{
+ struct xfs_rud_log_item *rudp;
+
+ ASSERT(tp != NULL);
+ ASSERT(nextents > 0);
+
+ rudp = xfs_rud_init(tp->t_mountp, ruip, nextents);
+ ASSERT(rudp != NULL);
+
+ /*
+ * Get a log_item_desc to point at the new item.
+ */
+ xfs_trans_add_item(tp, &rudp->rud_item);
+ return rudp;
+}
+
+/*
+ * Finish an rmap update and log it to the RUD. Note that the transaction is
+ * marked dirty regardless of whether the rmap update succeeds or fails to
+ * support the RUI/RUD lifecycle rules.
+ */
+int
+xfs_trans_log_finish_rmap_update(
+ struct xfs_trans *tp,
+ struct xfs_rud_log_item *rudp,
+ enum xfs_rmap_intent_type type,
+ __uint64_t owner,
+ int whichfork,
+ xfs_fileoff_t startoff,
+ xfs_fsblock_t startblock,
+ xfs_filblks_t blockcount,
+ xfs_exntst_t state)
+{
+ uint next_extent;
+ struct xfs_map_extent *rmap;
+ int error;
+
+ /* XXX: actually finish the rmap update here */
+ error = -EFSCORRUPTED;
+
+ /*
+ * Mark the transaction dirty, even on error. This ensures the
+ * transaction is aborted, which:
+ *
+ * 1.) releases the RUI and frees the RUD
+ * 2.) shuts down the filesystem
+ */
+ tp->t_flags |= XFS_TRANS_DIRTY;
+ rudp->rud_item.li_desc->lid_flags |= XFS_LID_DIRTY;
+
+ next_extent = rudp->rud_next_extent;
+ ASSERT(next_extent < rudp->rud_format.rud_nextents);
+ rmap = &(rudp->rud_format.rud_extents[next_extent]);
+ rmap->me_owner = owner;
+ rmap->me_startblock = startblock;
+ rmap->me_startoff = startoff;
+ rmap->me_len = blockcount;
+ xfs_trans_set_rmap_flags(rmap, type, whichfork, state);
+ rudp->rud_next_extent++;
+
+ return error;
+}