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Diffstat (limited to 'fs/xfs/libxfs/xfs_zones.h')
-rw-r--r--fs/xfs/libxfs/xfs_zones.h35
1 files changed, 35 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_zones.h b/fs/xfs/libxfs/xfs_zones.h
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index 000000000000..c4f1367b2cca
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_zones.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LIBXFS_ZONES_H
+#define _LIBXFS_ZONES_H
+
+struct xfs_rtgroup;
+
+/*
+ * In order to guarantee forward progress for GC we need to reserve at least
+ * two zones: one that will be used for moving data into and one spare zone
+ * making sure that we have enough space to relocate a nearly-full zone.
+ * To allow for slightly sloppy accounting for when we need to reserve the
+ * second zone, we actually reserve three as that is easier than doing fully
+ * accurate bookkeeping.
+ */
+#define XFS_GC_ZONES 3U
+
+/*
+ * In addition we need two zones for user writes, one open zone for writing
+ * and one to still have available blocks without resetting the open zone
+ * when data in the open zone has been freed.
+ */
+#define XFS_RESERVED_ZONES (XFS_GC_ZONES + 1)
+#define XFS_MIN_ZONES (XFS_RESERVED_ZONES + 1)
+
+/*
+ * Always keep one zone out of the general open zone pool to allow for GC to
+ * happen while other writers are waiting for free space.
+ */
+#define XFS_OPEN_GC_ZONES 1U
+#define XFS_MIN_OPEN_ZONES (XFS_OPEN_GC_ZONES + 1U)
+
+bool xfs_zone_validate(struct blk_zone *zone, struct xfs_rtgroup *rtg,
+ xfs_rgblock_t *write_pointer);
+
+#endif /* _LIBXFS_ZONES_H */