1 files changed, 299 insertions, 0 deletions
diff --git a/fs/xfs/scrub/rtbitmap.c b/fs/xfs/scrub/rtbitmap.c
new file mode 100644
index 000000000000..d5ff8609dbfb
--- /dev/null
+++ b/fs/xfs/scrub/rtbitmap.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_btree.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_rtbitmap.h"
+#include "xfs_inode.h"
+#include "xfs_bmap.h"
+#include "xfs_bit.h"
+#include "xfs_rtgroup.h"
+#include "xfs_sb.h"
+#include "xfs_rmap.h"
+#include "xfs_rtrmap_btree.h"
+#include "xfs_exchmaps.h"
+#include "xfs_zone_alloc.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/repair.h"
+#include "scrub/tempexch.h"
+#include "scrub/rtbitmap.h"
+#include "scrub/btree.h"
+
+/* Set us up with the realtime metadata locked. */
+int
+xchk_setup_rtbitmap(
+	struct xfs_scrub	*sc)
+{
+	struct xfs_mount	*mp = sc->mp;
+	struct xchk_rtbitmap	*rtb;
+	int			error;
+
+	if (xchk_need_intent_drain(sc))
+		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
+
+	rtb = kzalloc(struct_size(rtb, words, xchk_rtbitmap_wordcnt(sc)),
+			XCHK_GFP_FLAGS);
+	if (!rtb)
+		return -ENOMEM;
+	sc->buf = rtb;
+	rtb->sc = sc;
+
+	error = xchk_rtgroup_init(sc, sc->sm->sm_agno, &sc->sr);
+	if (error)
+		return error;
+
+	if (xchk_could_repair(sc)) {
+		error = xrep_setup_rtbitmap(sc, rtb);
+		if (error)
+			return error;
+	}
+
+	error = xchk_trans_alloc(sc, rtb->resblks);
+	if (error)
+		return error;
+
+	error = xchk_install_live_inode(sc, rtg_bitmap(sc->sr.rtg));
+	if (error)
+		return error;
+
+	error = xchk_ino_dqattach(sc);
+	if (error)
+		return error;
+
+	error = xchk_rtgroup_lock(sc, &sc->sr, XCHK_RTGLOCK_ALL);
+	if (error)
+		return error;
+
+	/*
+	 * Now that we've locked the rtbitmap, we can't race with growfsrt
+	 * trying to expand the bitmap or change the size of the rt volume.
+	 * Hence it is safe to compute and check the geometry values.
+	 */
+	if (mp->m_sb.sb_rblocks) {
+		rtb->rextents = xfs_blen_to_rtbxlen(mp, mp->m_sb.sb_rblocks);
+		rtb->rextslog = xfs_compute_rextslog(rtb->rextents);
+		rtb->rbmblocks = xfs_rtbitmap_blockcount(mp);
+	}
+
+	return 0;
+}
+
+/* Per-rtgroup bitmap contents. */
+
+/* Cross-reference rtbitmap entries with other metadata. */
+STATIC void
+xchk_rtbitmap_xref(
+	struct xchk_rtbitmap	*rtb,
+	xfs_rtblock_t		startblock,
+	xfs_rtblock_t		blockcount)
+{
+	struct xfs_scrub	*sc = rtb->sc;
+	xfs_rgblock_t		rgbno = xfs_rtb_to_rgbno(sc->mp, startblock);
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return;
+	if (!sc->sr.rmap_cur)
+		return;
+
+	xchk_xref_has_no_rt_owner(sc, rgbno, blockcount);
+	xchk_xref_is_not_rt_shared(sc, rgbno, blockcount);
+	xchk_xref_is_not_rt_cow_staging(sc, rgbno, blockcount);
+
+	if (rtb->next_free_rgbno < rgbno)
+		xchk_xref_has_rt_owner(sc, rtb->next_free_rgbno,
+				rgbno - rtb->next_free_rgbno);
+	rtb->next_free_rgbno = rgbno + blockcount;
+}
+
+/* Scrub a free extent record from the realtime bitmap. */
+STATIC int
+xchk_rtbitmap_rec(
+	struct xfs_rtgroup	*rtg,
+	struct xfs_trans	*tp,
+	const struct xfs_rtalloc_rec *rec,
+	void			*priv)
+{
+	struct xchk_rtbitmap	*rtb = priv;
+	struct xfs_scrub	*sc = rtb->sc;
+	xfs_rtblock_t		startblock;
+	xfs_filblks_t		blockcount;
+
+	startblock = xfs_rtx_to_rtb(rtg, rec->ar_startext);
+	blockcount = xfs_rtxlen_to_extlen(rtg_mount(rtg), rec->ar_extcount);
+
+	if (!xfs_verify_rtbext(rtg_mount(rtg), startblock, blockcount))
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+
+	xchk_rtbitmap_xref(rtb, startblock, blockcount);
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return -ECANCELED;
+
+	return 0;
+}
+
+/* Make sure the entire rtbitmap file is mapped with written extents. */
+STATIC int
+xchk_rtbitmap_check_extents(
+	struct xfs_scrub	*sc)
+{
+	struct xfs_bmbt_irec	map;
+	struct xfs_iext_cursor	icur;
+	struct xfs_mount	*mp = sc->mp;
+	struct xfs_inode	*ip = sc->ip;
+	xfs_fileoff_t		off = 0;
+	xfs_fileoff_t		endoff;
+	int			error = 0;
+
+	/* Mappings may not cross or lie beyond EOF. */
+	endoff = XFS_B_TO_FSB(mp, ip->i_disk_size);
+	if (xfs_iext_lookup_extent(ip, &ip->i_df, endoff, &icur, &map)) {
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, endoff);
+		return 0;
+	}
+
+	while (off < endoff) {
+		int		nmap = 1;
+
+		if (xchk_should_terminate(sc, &error) ||
+		    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+			break;
+
+		/* Make sure we have a written extent. */
+		error = xfs_bmapi_read(ip, off, endoff - off, &map, &nmap,
+				XFS_DATA_FORK);
+		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
+			break;
+
+		if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) {
+			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
+			break;
+		}
+
+		off += map.br_blockcount;
+	}
+
+	return error;
+}
+
+/* Scrub this group's realtime bitmap. */
+int
+xchk_rtbitmap(
+	struct xfs_scrub	*sc)
+{
+	struct xfs_mount	*mp = sc->mp;
+	struct xfs_rtgroup	*rtg = sc->sr.rtg;
+	struct xfs_inode	*rbmip = rtg_bitmap(rtg);
+	struct xchk_rtbitmap	*rtb = sc->buf;
+	xfs_rgblock_t		last_rgbno;
+	int			error;
+
+	/* Is sb_rextents correct? */
+	if (mp->m_sb.sb_rextents != rtb->rextents) {
+		xchk_ino_set_corrupt(sc, rbmip->i_ino);
+		return 0;
+	}
+
+	/* Is sb_rextslog correct? */
+	if (mp->m_sb.sb_rextslog != rtb->rextslog) {
+		xchk_ino_set_corrupt(sc, rbmip->i_ino);
+		return 0;
+	}
+
+	/*
+	 * Is sb_rbmblocks large enough to handle the current rt volume?  In no
+	 * case can we exceed 4bn bitmap blocks since the super field is a u32.
+	 */
+	if (rtb->rbmblocks > U32_MAX) {
+		xchk_ino_set_corrupt(sc, rbmip->i_ino);
+		return 0;
+	}
+	if (mp->m_sb.sb_rbmblocks != rtb->rbmblocks) {
+		xchk_ino_set_corrupt(sc, rbmip->i_ino);
+		return 0;
+	}
+
+	/* The bitmap file length must be aligned to an fsblock. */
+	if (rbmip->i_disk_size & mp->m_blockmask) {
+		xchk_ino_set_corrupt(sc, rbmip->i_ino);
+		return 0;
+	}
+
+	/*
+	 * Is the bitmap file itself large enough to handle the rt volume?
+	 * growfsrt expands the bitmap file before updating sb_rextents, so the
+	 * file can be larger than sb_rbmblocks.
+	 */
+	if (rbmip->i_disk_size < XFS_FSB_TO_B(mp, rtb->rbmblocks)) {
+		xchk_ino_set_corrupt(sc, rbmip->i_ino);
+		return 0;
+	}
+
+	/* Invoke the fork scrubber. */
+	error = xchk_metadata_inode_forks(sc);
+	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+		return error;
+
+	error = xchk_rtbitmap_check_extents(sc);
+	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+		return error;
+
+	rtb->next_free_rgbno = 0;
+	error = xfs_rtalloc_query_all(rtg, sc->tp, xchk_rtbitmap_rec, rtb);
+	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
+		return error;
+
+	/*
+	 * Check that the are rmappings for all rt extents between the end of
+	 * the last free extent we saw and the last possible extent in the rt
+	 * group.
+	 */
+	last_rgbno = rtg->rtg_extents * mp->m_sb.sb_rextsize - 1;
+	if (rtb->next_free_rgbno < last_rgbno)
+		xchk_xref_has_rt_owner(sc, rtb->next_free_rgbno,
+				last_rgbno - rtb->next_free_rgbno);
+	return 0;
+}
+
+/* xref check that the extent is not free in the rtbitmap */
+void
+xchk_xref_is_used_rt_space(
+	struct xfs_scrub	*sc,
+	xfs_rtblock_t		rtbno,
+	xfs_extlen_t		len)
+{
+	struct xfs_rtgroup	*rtg = sc->sr.rtg;
+	xfs_rtxnum_t		startext;
+	xfs_rtxnum_t		endext;
+	bool			is_free;
+	int			error;
+
+	if (xchk_skip_xref(sc->sm))
+		return;
+
+	if (xfs_has_zoned(sc->mp)) {
+		if (!xfs_zone_rgbno_is_valid(rtg,
+				xfs_rtb_to_rgbno(sc->mp, rtbno) + len - 1))
+			xchk_ino_xref_set_corrupt(sc, rtg_rmap(rtg)->i_ino);
+		return;
+	}
+
+	startext = xfs_rtb_to_rtx(sc->mp, rtbno);
+	endext = xfs_rtb_to_rtx(sc->mp, rtbno + len - 1);
+	error = xfs_rtalloc_extent_is_free(rtg, sc->tp, startext,
+			endext - startext + 1, &is_free);
+	if (!xchk_should_check_xref(sc, &error, NULL))
+		return;
+	if (is_free)
+		xchk_ino_xref_set_corrupt(sc, rtg_bitmap(rtg)->i_ino);
+}