[PATCH 3/3] xfs: online repair of realtime summaries

Darrick J. Wong
2023-12-31T20:32:35Z

Repair the realtime summary data by constructing a new rtsummary file in
the scrub temporary file, then atomically swapping the contents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/Makefile | 1
fs/xfs/scrub/common.c | 1
fs/xfs/scrub/repair.h | 3 +
fs/xfs/scrub/rtsummary.c | 33 ++++---
fs/xfs/scrub/rtsummary.h | 37 ++++++++
fs/xfs/scrub/rtsummary_repair.c | 177 +++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/scrub.c | 3 -
7 files changed, 239 insertions(+), 16 deletions(-)
create mode 100644 fs/xfs/scrub/rtsummary.h
create mode 100644 fs/xfs/scrub/rtsummary_repair.c

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 9ce43c3037d2c..62e38f70c304b 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -213,6 +213,7 @@ xfs-y += $(addprefix scrub/, \

xfs-$(CONFIG_XFS_RT) += $(addprefix scrub/, \
rtbitmap_repair.o \
+ rtsummary_repair.o \
)

xfs-$(CONFIG_XFS_QUOTA) += $(addprefix scrub/, \
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 78ffd6137d498..c16cd9774f525 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -31,6 +31,7 @@
#include "xfs_ag.h"
#include "xfs_error.h"
#include "xfs_quota.h"
+#include "xfs_swapext.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index 38aa5c9649d71..06125d0a2c602 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -126,8 +126,10 @@ int xrep_fscounters(struct xfs_scrub *sc);

#ifdef CONFIG_XFS_RT
int xrep_rtbitmap(struct xfs_scrub *sc);
+int xrep_rtsummary(struct xfs_scrub *sc);
#else
# define xrep_rtbitmap xrep_notsupported
+# define xrep_rtsummary xrep_notsupported
#endif /* CONFIG_XFS_RT */

#ifdef CONFIG_XFS_QUOTA
@@ -212,6 +214,7 @@ xrep_setup_nothing(
#define xrep_quotacheck xrep_notsupported
#define xrep_nlinks xrep_notsupported
#define xrep_fscounters xrep_notsupported
+#define xrep_rtsummary xrep_notsupported

#endif /* CONFIG_XFS_ONLINE_REPAIR */

diff --git a/fs/xfs/scrub/rtsummary.c b/fs/xfs/scrub/rtsummary.c
index b0d90426a5cb8..5d1622203c8a9 100644
--- a/fs/xfs/scrub/rtsummary.c
+++ b/fs/xfs/scrub/rtsummary.c
@@ -16,10 +16,14 @@
#include "xfs_rtbitmap.h"
#include "xfs_bit.h"
#include "xfs_bmap.h"
+#include "xfs_swapext.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
#include "scrub/xfile.h"
+#include "scrub/repair.h"
+#include "scrub/tempswap.h"
+#include "scrub/rtsummary.h"

/*
* Realtime Summary
@@ -31,18 +35,6 @@
* (potentially large) amount of data in pageable memory.
*/

-struct xchk_rtsummary {
- struct xfs_rtalloc_args args;
-
- uint64_t rextents;
- uint64_t rbmblocks;
- uint64_t rsumsize;
- unsigned int rsumlevels;
-
- /* Memory buffer for the summary comparison. */
- union xfs_suminfo_raw words[];
-};
-
/* Set us up to check the rtsummary file. */
int
xchk_setup_rtsummary(
@@ -59,6 +51,12 @@ xchk_setup_rtsummary(
return -ENOMEM;
sc->buf = rts;

+ if (xchk_could_repair(sc)) {
+ error = xrep_setup_rtsummary(sc, rts);
+ if (error)
+ return error;
+ }
+
/*
* Create an xfile to construct a new rtsummary file. The xfile allows
* us to avoid pinning kernel memory for this purpose.
@@ -69,7 +67,7 @@ xchk_setup_rtsummary(
if (error)
return error;

- error = xchk_trans_alloc(sc, 0);
+ error = xchk_trans_alloc(sc, rts->resblks);
if (error)
return error;

@@ -134,7 +132,7 @@ xfsum_store(
sumoff << XFS_WORDLOG);
}

-static inline int
+inline int
xfsum_copyout(
struct xfs_scrub *sc,
xfs_rtsumoff_t sumoff,
@@ -361,7 +359,12 @@ xchk_rtsummary(
error = xchk_rtsum_compare(sc);

out_rbm:
- /* Unlock the rtbitmap since we're done with it. */
+ /*
+ * Unlock the rtbitmap since we're done with it. All other writers of
+ * the rt free space metadata grab the bitmap and summary ILOCKs in
+ * that order, so we're still protected against allocation activities
+ * even if we continue on to the repair function.
+ */
xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
return error;
}
diff --git a/fs/xfs/scrub/rtsummary.h b/fs/xfs/scrub/rtsummary.h
new file mode 100644
index 0000000000000..8bcffd53fc2e2
--- /dev/null
+++ b/fs/xfs/scrub/rtsummary.h
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_RTSUMMARY_H__
+#define __XFS_SCRUB_RTSUMMARY_H__
+
+struct xchk_rtsummary {
+#ifdef CONFIG_XFS_ONLINE_REPAIR
+ struct xrep_tempswap tempswap;
+#endif
+ struct xfs_rtalloc_args args;
+
+ uint64_t rextents;
+ uint64_t rbmblocks;
+ uint64_t rsumsize;
+ unsigned int rsumlevels;
+ unsigned int resblks;
+
+ /* suminfo position of xfile as we write buffers to disk. */
+ xfs_rtsumoff_t prep_wordoff;
+
+ /* Memory buffer for the summary comparison. */
+ union xfs_suminfo_raw words[];
+};
+
+int xfsum_copyout(struct xfs_scrub *sc, xfs_rtsumoff_t sumoff,
+ union xfs_suminfo_raw *rawinfo, unsigned int nr_words);
+
+#ifdef CONFIG_XFS_ONLINE_REPAIR
+int xrep_setup_rtsummary(struct xfs_scrub *sc, struct xchk_rtsummary *rts);
+#else
+# define xrep_setup_rtsummary(sc, rts) (0)
+#endif /* CONFIG_XFS_ONLINE_REPAIR */
+
+#endif /* __XFS_SCRUB_RTSUMMARY_H__ */
diff --git a/fs/xfs/scrub/rtsummary_repair.c b/fs/xfs/scrub/rtsummary_repair.c
new file mode 100644
index 0000000000000..058c5ebabf9a2
--- /dev/null
+++ b/fs/xfs/scrub/rtsummary_repair.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020-2024 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_rtalloc.h"
+#include "xfs_inode.h"
+#include "xfs_bit.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_swapext.h"
+#include "xfs_rtbitmap.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/repair.h"
+#include "scrub/tempfile.h"
+#include "scrub/tempswap.h"
+#include "scrub/reap.h"
+#include "scrub/xfile.h"
+#include "scrub/rtsummary.h"
+
+/* Set us up to repair the rtsummary file. */
+int
+xrep_setup_rtsummary(
+ struct xfs_scrub *sc,
+ struct xchk_rtsummary *rts)
+{
+ struct xfs_mount *mp = sc->mp;
+ unsigned long long blocks;
+ int error;
+
+ error = xrep_tempfile_create(sc, S_IFREG);
+ if (error)
+ return error;
+
+ /*
+ * If we're doing a repair, we reserve enough blocks to write out a
+ * completely new summary file, plus twice as many blocks as we would
+ * need if we can only allocate one block per data fork mapping. This
+ * should cover the preallocation of the temporary file and swapping
+ * the extent mappings.
+ *
+ * We cannot use xfs_swapext_estimate because we have not yet
+ * constructed the replacement rtsummary and therefore do not know how
+ * many extents it will use. By the time we do, we will have a dirty
+ * transaction (which we cannot drop because we cannot drop the
+ * rtsummary ILOCK) and cannot ask for more reservation.
+ */
+ blocks = XFS_B_TO_FSB(mp, mp->m_rsumsize);
+ blocks += xfs_bmbt_calc_size(mp, blocks) * 2;
+ if (blocks > UINT_MAX)
+ return -EOPNOTSUPP;
+
+ rts->resblks += blocks;
+
+ /*
+ * Grab support for atomic extent swapping before we allocate any
+ * transactions or grab ILOCKs.
+ */
+ return xrep_tempswap_grab_log_assist(sc);
+}
+
+static int
+xrep_rtsummary_prep_buf(
+ struct xfs_scrub *sc,
+ struct xfs_buf *bp,
+ void *data)
+{
+ struct xchk_rtsummary *rts = data;
+ struct xfs_mount *mp = sc->mp;
+ union xfs_suminfo_raw *ondisk;
+ int error;
+
+ rts->args.mp = sc->mp;
+ rts->args.tp = sc->tp;
+ rts->args.sumbp = bp;
+ ondisk = xfs_rsumblock_infoptr(&rts->args, 0);
+ rts->args.sumbp = NULL;
+
+ bp->b_ops = &xfs_rtbuf_ops;
+
+ error = xfsum_copyout(sc, rts->prep_wordoff, ondisk, mp->m_blockwsize);
+ if (error)
+ return error;
+
+ rts->prep_wordoff += mp->m_blockwsize;
+ xfs_trans_buf_set_type(sc->tp, bp, XFS_BLFT_RTSUMMARY_BUF);
+ return 0;
+}
+
+/* Repair the realtime summary. */
+int
+xrep_rtsummary(
+ struct xfs_scrub *sc)
+{
+ struct xchk_rtsummary *rts = sc->buf;
+ struct xfs_mount *mp = sc->mp;
+ xfs_filblks_t rsumblocks;
+ int error;
+
+ /* We require the rmapbt to rebuild anything. */
+ if (!xfs_has_rmapbt(mp))
+ return -EOPNOTSUPP;
+
+ /* Walk away if we disagree on the size of the rt bitmap. */
+ if (rts->rbmblocks != mp->m_sb.sb_rbmblocks)
+ return 0;
+
+ /* Make sure any problems with the fork are fixed. */
+ error = xrep_metadata_inode_forks(sc);
+ if (error)
+ return error;
+
+ /*
+ * Try to take ILOCK_EXCL of the temporary file. We had better be the
+ * only ones holding onto this inode, but we can't block while holding
+ * the rtsummary file's ILOCK_EXCL.
+ */
+ while (!xrep_tempfile_ilock_nowait(sc)) {
+ if (xchk_should_terminate(sc, &error))
+ return error;
+ delay(1);
+ }
+
+ /* Make sure we have space allocated for the entire summary file. */
+ rsumblocks = XFS_B_TO_FSB(mp, rts->rsumsize);
+ xfs_trans_ijoin(sc->tp, sc->ip, 0);
+ xfs_trans_ijoin(sc->tp, sc->tempip, 0);
+ error = xrep_tempfile_prealloc(sc, 0, rsumblocks);
+ if (error)
+ return error;
+
+ /* Last chance to abort before we start committing fixes. */
+ if (xchk_should_terminate(sc, &error))
+ return error;
+
+ /* Copy the rtsummary file that we generated. */
+ error = xrep_tempfile_copyin(sc, 0, rsumblocks,
+ xrep_rtsummary_prep_buf, rts);
+ if (error)
+ return error;
+ error = xrep_tempfile_set_isize(sc, rts->rsumsize);
+ if (error)
+ return error;
+
+ /*
+ * Now swap the extents. Nothing in repair uses the temporary buffer,
+ * so we can reuse it for the tempfile swapext information.
+ */
+ error = xrep_tempswap_trans_reserve(sc, XFS_DATA_FORK, &rts->tempswap);
+ if (error)
+ return error;
+
+ error = xrep_tempswap_contents(sc, &rts->tempswap);
+ if (error)
+ return error;
+
+ /* Reset incore state and blow out the summary cache. */
+ if (mp->m_rsum_cache)
+ memset(mp->m_rsum_cache, 0xFF, mp->m_sb.sb_rbmblocks);
+
+ mp->m_rsumlevels = rts->rsumlevels;
+ mp->m_rsumsize = rts->rsumsize;
+
+ /* Free the old rtsummary blocks if they're not in use. */
+ return xrep_reap_ifork(sc, sc->tempip, XFS_DATA_FORK);
+}
diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index afc82f1e40ffb..9af91874e58b9 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -18,6 +18,7 @@
#include "xfs_buf_xfile.h"
#include "xfs_rmap.h"
#include "xfs_xchgrange.h"
+#include "xfs_swapext.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
@@ -357,7 +358,7 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
.type = ST_FS,
.setup = xchk_setup_rtsummary,
.scrub = xchk_rtsummary,
- .repair = xrep_notsupported,
+ .repair = xrep_rtsummary,
},
[XFS_SCRUB_TYPE_UQUOTA] = { /* user quota */
.type = ST_FS,