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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 18:50:03 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 18:50:03 +0000
commit01a69402cf9d38ff180345d55c2ee51c7e89fbc7 (patch)
treeb406c5242a088c4f59c6e4b719b783f43aca6ae9 /fs/xfs/scrub/agb_bitmap.c
parentAdding upstream version 6.7.12. (diff)
downloadlinux-01a69402cf9d38ff180345d55c2ee51c7e89fbc7.tar.xz
linux-01a69402cf9d38ff180345d55c2ee51c7e89fbc7.zip
Adding upstream version 6.8.9.upstream/6.8.9
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/xfs/scrub/agb_bitmap.c')
-rw-r--r--fs/xfs/scrub/agb_bitmap.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/fs/xfs/scrub/agb_bitmap.c b/fs/xfs/scrub/agb_bitmap.c
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+++ b/fs/xfs/scrub/agb_bitmap.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2018-2023 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_shared.h"
+#include "xfs_bit.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_btree.h"
+#include "bitmap.h"
+#include "scrub/agb_bitmap.h"
+
+/*
+ * Record all btree blocks seen while iterating all records of a btree.
+ *
+ * We know that the btree query_all function starts at the left edge and walks
+ * towards the right edge of the tree. Therefore, we know that we can walk up
+ * the btree cursor towards the root; if the pointer for a given level points
+ * to the first record/key in that block, we haven't seen this block before;
+ * and therefore we need to remember that we saw this block in the btree.
+ *
+ * So if our btree is:
+ *
+ * 4
+ * / | \
+ * 1 2 3
+ *
+ * Pretend for this example that each leaf block has 100 btree records. For
+ * the first btree record, we'll observe that bc_levels[0].ptr == 1, so we
+ * record that we saw block 1. Then we observe that bc_levels[1].ptr == 1, so
+ * we record block 4. The list is [1, 4].
+ *
+ * For the second btree record, we see that bc_levels[0].ptr == 2, so we exit
+ * the loop. The list remains [1, 4].
+ *
+ * For the 101st btree record, we've moved onto leaf block 2. Now
+ * bc_levels[0].ptr == 1 again, so we record that we saw block 2. We see that
+ * bc_levels[1].ptr == 2, so we exit the loop. The list is now [1, 4, 2].
+ *
+ * For the 102nd record, bc_levels[0].ptr == 2, so we continue.
+ *
+ * For the 201st record, we've moved on to leaf block 3.
+ * bc_levels[0].ptr == 1, so we add 3 to the list. Now it is [1, 4, 2, 3].
+ *
+ * For the 300th record we just exit, with the list being [1, 4, 2, 3].
+ */
+
+/* Mark a btree block to the agblock bitmap. */
+STATIC int
+xagb_bitmap_visit_btblock(
+ struct xfs_btree_cur *cur,
+ int level,
+ void *priv)
+{
+ struct xagb_bitmap *bitmap = priv;
+ struct xfs_buf *bp;
+ xfs_fsblock_t fsbno;
+ xfs_agblock_t agbno;
+
+ xfs_btree_get_block(cur, level, &bp);
+ if (!bp)
+ return 0;
+
+ fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
+ agbno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
+
+ return xagb_bitmap_set(bitmap, agbno, 1);
+}
+
+/* Mark all (per-AG) btree blocks in the agblock bitmap. */
+int
+xagb_bitmap_set_btblocks(
+ struct xagb_bitmap *bitmap,
+ struct xfs_btree_cur *cur)
+{
+ return xfs_btree_visit_blocks(cur, xagb_bitmap_visit_btblock,
+ XFS_BTREE_VISIT_ALL, bitmap);
+}
+
+/*
+ * Record all the buffers pointed to by the btree cursor. Callers already
+ * engaged in a btree walk should call this function to capture the list of
+ * blocks going from the leaf towards the root.
+ */
+int
+xagb_bitmap_set_btcur_path(
+ struct xagb_bitmap *bitmap,
+ struct xfs_btree_cur *cur)
+{
+ int i;
+ int error;
+
+ for (i = 0; i < cur->bc_nlevels && cur->bc_levels[i].ptr == 1; i++) {
+ error = xagb_bitmap_visit_btblock(cur, i, bitmap);
+ if (error)
+ return error;
+ }
+
+ return 0;
+}