1 files changed, 71 insertions, 0 deletions

diff --git a/fs/xfs/scrub/attr.h b/fs/xfs/scrub/attr.h
new file mode 100644
index 000000000000..13a1d2e8424d
--- /dev/null
+++ b/fs/xfs/scrub/attr.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+#ifndef __XFS_SCRUB_ATTR_H__
+#define __XFS_SCRUB_ATTR_H__
+
+/*
+ * Temporary storage for online scrub and repair of extended attributes.
+ */
+struct xchk_xattr_buf {
+        /* Size of @buf, in bytes. */
+        size_t                  sz;
+
+        /*
+         * Memory buffer -- either used for extracting attr values while
+         * walking the attributes; or for computing attr block bitmaps when
+         * checking the attribute tree.
+         *
+         * Each bitmap contains enough bits to track every byte in an attr
+         * block (rounded up to the size of an unsigned long).  The attr block
+         * used space bitmap starts at the beginning of the buffer; the free
+         * space bitmap follows immediately after; and we have a third buffer
+         * for storing intermediate bitmap results.
+         */
+        uint8_t                 buf[0];
+};
+
+/* A place to store attribute values. */
+static inline uint8_t *
+xchk_xattr_valuebuf(
+        struct xfs_scrub        *sc)
+{
+        struct xchk_xattr_buf   *ab = sc->buf;
+
+        return ab->buf;
+}
+
+/* A bitmap of space usage computed by walking an attr leaf block. */
+static inline unsigned long *
+xchk_xattr_usedmap(
+        struct xfs_scrub        *sc)
+{
+        struct xchk_xattr_buf   *ab = sc->buf;
+
+        return (unsigned long *)ab->buf;
+}
+
+/* A bitmap of free space computed by walking attr leaf block free info. */
+static inline unsigned long *
+xchk_xattr_freemap(
+        struct xfs_scrub        *sc)
+{
+        return xchk_xattr_usedmap(sc) +
+                        BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
+}
+
+/* A bitmap used to hold temporary results. */
+static inline unsigned long *
+xchk_xattr_dstmap(
+        struct xfs_scrub        *sc)
+{
+        return xchk_xattr_freemap(sc) +
+                        BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
+}
+
+int xchk_setup_xattr_buf(struct xfs_scrub *sc, size_t value_size,
+                xfs_km_flags_t flags);
+
+#endif  /* __XFS_SCRUB_ATTR_H__ */