[PATCHSET v29.4 05/13] xfs: online repair of realtime summaries

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* [PATCHSET v29.4 05/13] xfs: online repair of realtime summaries
@ 2024-02-27  2:18 Darrick J. Wong
  2024-02-27  2:25 ` [PATCH 1/3] xfs: support preallocating and copying content into temporary files Darrick J. Wong
                   ` (2 more replies)
  0 siblings, 3 replies; 12+ messages in thread
From: Darrick J. Wong @ 2024-02-27  2:18 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

Hi all,

We now have all the infrastructure we need to repair file metadata.
We'll begin with the realtime summary file, because it is the least
complex data structure.  To support this we need to add three more
pieces to the temporary file code from the previous patchset --
preallocating space in the temp file, formatting metadata into that
space and writing the blocks to disk, and swapping the fork mappings
atomically.

After that, the actual reconstruction of the realtime summary
information is pretty simple, since we can simply write the incore
copy computed by the rtsummary scrubber to the temporary file, swap the
contents, and reap the old blocks.

If you're going to start using this code, I strongly recommend pulling
from my git trees, which are linked below.

This has been running on the djcloud for months with no problems.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-rtsummary

xfsprogs git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=repair-rtsummary

fstests git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=repair-rtsummary
---
Commits in this patchset:
 * xfs: support preallocating and copying content into temporary files
 * xfs: teach the tempfile to set up atomic file content exchanges
 * xfs: online repair of realtime summaries
---
 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            |   11 +
 fs/xfs/scrub/scrub.h            |    7 +
 fs/xfs/scrub/tempexch.h         |   21 ++
 fs/xfs/scrub/tempfile.c         |  391 +++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/tempfile.h         |   15 +
 fs/xfs/scrub/trace.h            |   40 ++++
 12 files changed, 718 insertions(+), 19 deletions(-)
 create mode 100644 fs/xfs/scrub/rtsummary.h
 create mode 100644 fs/xfs/scrub/rtsummary_repair.c
 create mode 100644 fs/xfs/scrub/tempexch.h

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 1/3] xfs: support preallocating and copying content into temporary files
  2024-02-27  2:18 [PATCHSET v29.4 05/13] xfs: online repair of realtime summaries Darrick J. Wong
@ 2024-02-27  2:25 ` Darrick J. Wong
  2024-02-27 18:17   ` Christoph Hellwig
  2024-02-27  2:26 ` [PATCH 2/3] xfs: teach the tempfile to set up atomic file content exchanges Darrick J. Wong
  2024-02-27  2:26 ` [PATCH 3/3] xfs: online repair of realtime summaries Darrick J. Wong
  2 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2024-02-27  2:25 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

From: Darrick J. Wong <djwong@kernel.org>

Create the routines we need to preallocate space in a temporary ondisk
file and then copy the contents of an xfile into the tempfile.  The
upcoming rtsummary repair feature will construct the contents of a
realtime summary file in memory, after which it will want to copy all
that into the ondisk temporary file before atomically committing the new
rtsummary contents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/scrub/tempfile.c |  197 +++++++++++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/tempfile.h |   15 ++++
 fs/xfs/scrub/trace.h    |   39 +++++++++
 3 files changed, 251 insertions(+)


diff --git a/fs/xfs/scrub/tempfile.c b/fs/xfs/scrub/tempfile.c
index 68d245749bc1e..83e683e165618 100644
--- a/fs/xfs/scrub/tempfile.c
+++ b/fs/xfs/scrub/tempfile.c
@@ -14,14 +14,18 @@
 #include "xfs_inode.h"
 #include "xfs_ialloc.h"
 #include "xfs_quota.h"
+#include "xfs_bmap.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_trans_space.h"
 #include "xfs_dir2.h"
 #include "xfs_exchrange.h"
+#include "xfs_defer.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
+#include "scrub/repair.h"
 #include "scrub/trace.h"
 #include "scrub/tempfile.h"
+#include "scrub/xfile.h"
 
 /*
  * Create a temporary file for reconstructing metadata, with the intention of
@@ -249,3 +253,196 @@ xrep_tempfile_rele(
 	xchk_irele(sc, sc->tempip);
 	sc->tempip = NULL;
 }
+
+/*
+ * Make sure that the given range of the data fork of the temporary file is
+ * mapped to written blocks.  The caller must ensure that both inodes are
+ * joined to the transaction.
+ */
+int
+xrep_tempfile_prealloc(
+	struct xfs_scrub	*sc,
+	xfs_fileoff_t		off,
+	xfs_filblks_t		len)
+{
+	struct xfs_bmbt_irec	map;
+	xfs_fileoff_t		end = off + len;
+	int			error;
+
+	ASSERT(sc->tempip != NULL);
+	ASSERT(!XFS_NOT_DQATTACHED(sc->mp, sc->tempip));
+
+	for (; off < end; off = map.br_startoff + map.br_blockcount) {
+		int		nmaps = 1;
+
+		/*
+		 * If we have a real extent mapping this block then we're
+		 * in ok shape.
+		 */
+		error = xfs_bmapi_read(sc->tempip, off, end - off, &map, &nmaps,
+				XFS_DATA_FORK);
+		if (error)
+			return error;
+		if (nmaps == 0) {
+			ASSERT(nmaps != 0);
+			return -EFSCORRUPTED;
+		}
+
+		if (xfs_bmap_is_written_extent(&map))
+			continue;
+
+		/*
+		 * If we find a delalloc reservation then something is very
+		 * very wrong.  Bail out.
+		 */
+		if (map.br_startblock == DELAYSTARTBLOCK)
+			return -EFSCORRUPTED;
+
+		/*
+		 * Make sure this block has a real zeroed extent allocated to
+		 * it.
+		 */
+		nmaps = 1;
+		error = xfs_bmapi_write(sc->tp, sc->tempip, off, end - off,
+				XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO, 0, &map,
+				&nmaps);
+		if (error)
+			return error;
+		if (nmaps != 1)
+			return -EFSCORRUPTED;
+
+		trace_xrep_tempfile_prealloc(sc, XFS_DATA_FORK, &map);
+
+		/* Commit new extent and all deferred work. */
+		error = xfs_defer_finish(&sc->tp);
+		if (error)
+			return error;
+	}
+
+	return 0;
+}
+
+/*
+ * Write data to each block of a file.  The given range of the tempfile's data
+ * fork must already be populated with written extents.
+ */
+int
+xrep_tempfile_copyin(
+	struct xfs_scrub	*sc,
+	xfs_fileoff_t		off,
+	xfs_filblks_t		len,
+	xrep_tempfile_copyin_fn	prep_fn,
+	void			*data)
+{
+	LIST_HEAD(buffers_list);
+	struct xfs_mount	*mp = sc->mp;
+	struct xfs_buf		*bp;
+	xfs_fileoff_t		flush_mask;
+	xfs_fileoff_t		end = off + len;
+	loff_t			pos = XFS_FSB_TO_B(mp, off);
+	int			error = 0;
+
+	ASSERT(S_ISREG(VFS_I(sc->tempip)->i_mode));
+
+	/* Flush buffers to disk every 512K */
+	flush_mask = XFS_B_TO_FSBT(mp, (1U << 19)) - 1;
+
+	for (; off < end; off++, pos += mp->m_sb.sb_blocksize) {
+		struct xfs_bmbt_irec	map;
+		int			nmaps = 1;
+
+		/* Read block mapping for this file block. */
+		error = xfs_bmapi_read(sc->tempip, off, 1, &map, &nmaps, 0);
+		if (error)
+			goto out_err;
+		if (nmaps == 0 || !xfs_bmap_is_written_extent(&map)) {
+			error = -EFSCORRUPTED;
+			goto out_err;
+		}
+
+		/* Get the metadata buffer for this offset in the file. */
+		error = xfs_trans_get_buf(sc->tp, mp->m_ddev_targp,
+				XFS_FSB_TO_DADDR(mp, map.br_startblock),
+				mp->m_bsize, 0, &bp);
+		if (error)
+			goto out_err;
+
+		trace_xrep_tempfile_copyin(sc, XFS_DATA_FORK, &map);
+
+		/* Read in a block's worth of data from the xfile. */
+		error = prep_fn(sc, bp, data);
+		if (error) {
+			xfs_trans_brelse(sc->tp, bp);
+			goto out_err;
+		}
+
+		/* Queue buffer, and flush if we have too much dirty data. */
+		xfs_buf_delwri_queue_here(bp, &buffers_list);
+		xfs_trans_brelse(sc->tp, bp);
+
+		if (!(off & flush_mask)) {
+			error = xfs_buf_delwri_submit(&buffers_list);
+			if (error)
+				goto out_err;
+		}
+	}
+
+	/*
+	 * Write the new blocks to disk.  If the ordered list isn't empty after
+	 * that, then something went wrong and we have to fail.  This should
+	 * never happen, but we'll check anyway.
+	 */
+	error = xfs_buf_delwri_submit(&buffers_list);
+	if (error)
+		goto out_err;
+
+	if (!list_empty(&buffers_list)) {
+		ASSERT(list_empty(&buffers_list));
+		error = -EIO;
+		goto out_err;
+	}
+
+	return 0;
+
+out_err:
+	xfs_buf_delwri_cancel(&buffers_list);
+	return error;
+}
+
+/*
+ * Set the temporary file's size.  Caller must join the tempfile to the scrub
+ * transaction and is responsible for adjusting block mappings as needed.
+ */
+int
+xrep_tempfile_set_isize(
+	struct xfs_scrub	*sc,
+	unsigned long long	isize)
+{
+	if (sc->tempip->i_disk_size == isize)
+		return 0;
+
+	sc->tempip->i_disk_size = isize;
+	i_size_write(VFS_I(sc->tempip), isize);
+	return xrep_tempfile_roll_trans(sc);
+}
+
+/*
+ * Roll a repair transaction involving the temporary file.  Caller must join
+ * both the temporary file and the file being scrubbed to the transaction.
+ * This function return with both inodes joined to a new scrub transaction,
+ * or the usual negative errno.
+ */
+int
+xrep_tempfile_roll_trans(
+	struct xfs_scrub	*sc)
+{
+	int			error;
+
+	xfs_trans_log_inode(sc->tp, sc->tempip, XFS_ILOG_CORE);
+	error = xrep_roll_trans(sc);
+	if (error)
+		return error;
+
+	xfs_trans_ijoin(sc->tp, sc->tempip, 0);
+	return 0;
+}
diff --git a/fs/xfs/scrub/tempfile.h b/fs/xfs/scrub/tempfile.h
index e165e0a3faf63..7980f9c4de552 100644
--- a/fs/xfs/scrub/tempfile.h
+++ b/fs/xfs/scrub/tempfile.h
@@ -17,6 +17,21 @@ void xrep_tempfile_iounlock(struct xfs_scrub *sc);
 void xrep_tempfile_ilock(struct xfs_scrub *sc);
 bool xrep_tempfile_ilock_nowait(struct xfs_scrub *sc);
 void xrep_tempfile_iunlock(struct xfs_scrub *sc);
+
+int xrep_tempfile_prealloc(struct xfs_scrub *sc, xfs_fileoff_t off,
+		xfs_filblks_t len);
+
+enum xfs_blft;
+
+typedef int (*xrep_tempfile_copyin_fn)(struct xfs_scrub *sc,
+		struct xfs_buf *bp, void *data);
+
+int xrep_tempfile_copyin(struct xfs_scrub *sc, xfs_fileoff_t off,
+		xfs_filblks_t len, xrep_tempfile_copyin_fn fn, void *data);
+
+int xrep_tempfile_set_isize(struct xfs_scrub *sc, unsigned long long isize);
+
+int xrep_tempfile_roll_trans(struct xfs_scrub *sc);
 #else
 static inline void xrep_tempfile_iolock_both(struct xfs_scrub *sc)
 {
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index e6c15004e6a17..50801d5914839 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -2308,6 +2308,45 @@ TRACE_EVENT(xrep_tempfile_create,
 		  __entry->temp_inum)
 );
 
+DECLARE_EVENT_CLASS(xrep_tempfile_class,
+	TP_PROTO(struct xfs_scrub *sc, int whichfork,
+		 struct xfs_bmbt_irec *irec),
+	TP_ARGS(sc, whichfork, irec),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(int, whichfork)
+		__field(xfs_fileoff_t, lblk)
+		__field(xfs_filblks_t, len)
+		__field(xfs_fsblock_t, pblk)
+		__field(int, state)
+	),
+	TP_fast_assign(
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->ino = sc->tempip->i_ino;
+		__entry->whichfork = whichfork;
+		__entry->lblk = irec->br_startoff;
+		__entry->len = irec->br_blockcount;
+		__entry->pblk = irec->br_startblock;
+		__entry->state = irec->br_state;
+	),
+	TP_printk("dev %d:%d ino 0x%llx whichfork %s fileoff 0x%llx fsbcount 0x%llx startblock 0x%llx state %d",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __print_symbolic(__entry->whichfork, XFS_WHICHFORK_STRINGS),
+		  __entry->lblk,
+		  __entry->len,
+		  __entry->pblk,
+		  __entry->state)
+);
+#define DEFINE_XREP_TEMPFILE_EVENT(name) \
+DEFINE_EVENT(xrep_tempfile_class, name, \
+	TP_PROTO(struct xfs_scrub *sc, int whichfork, \
+		 struct xfs_bmbt_irec *irec), \
+	TP_ARGS(sc, whichfork, irec))
+DEFINE_XREP_TEMPFILE_EVENT(xrep_tempfile_prealloc);
+DEFINE_XREP_TEMPFILE_EVENT(xrep_tempfile_copyin);
+
 TRACE_EVENT(xreap_ifork_extent,
 	TP_PROTO(struct xfs_scrub *sc, struct xfs_inode *ip, int whichfork,
 		 const struct xfs_bmbt_irec *irec),


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* Re: [PATCH 1/3] xfs: support preallocating and copying content into temporary files
  2024-02-27  2:25 ` [PATCH 1/3] xfs: support preallocating and copying content into temporary files Darrick J. Wong
@ 2024-02-27 18:17   ` Christoph Hellwig
  0 siblings, 0 replies; 12+ messages in thread
From: Christoph Hellwig @ 2024-02-27 18:17 UTC (permalink / raw)
  To: Darrick J. Wong; +Cc: linux-xfs

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 2/3] xfs: teach the tempfile to set up atomic file content exchanges
  2024-02-27  2:18 [PATCHSET v29.4 05/13] xfs: online repair of realtime summaries Darrick J. Wong
  2024-02-27  2:25 ` [PATCH 1/3] xfs: support preallocating and copying content into temporary files Darrick J. Wong
@ 2024-02-27  2:26 ` Darrick J. Wong
  2024-02-27 18:18   ` Christoph Hellwig
  2024-02-27  2:26 ` [PATCH 3/3] xfs: online repair of realtime summaries Darrick J. Wong
  2 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2024-02-27  2:26 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

From: Darrick J. Wong <djwong@kernel.org>

Create some new routines to exchange the contents of a temporary file
created to stage a repair with another ondisk file.  This will be used
by the realtime summary repair function to commit atomically the new
rtsummary data, which will be staged in the tempfile.

The rest of XFS coordinates access to the realtime metadata inodes
solely through the ILOCK.  For repair to hold its exclusive access to
the realtime summary file, it has to allocate a single large transaction
and roll it repeatedly throughout the repair while holding the ILOCK.
In turn, this means that for now there's only a partial file mapping
exchange implementation for the temporary file because we can only work
within an existing transaction.

For now, the only tempswap functions needed here are to estimate the
resource requirements of the exchange, reserve more space/quota to an
existing transaction, and kick off the actual exchange.  The rest will
be added in a later patch in preparation for repairing xattrs and
directories.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/scrub/scrub.c    |    8 +-
 fs/xfs/scrub/scrub.h    |    7 ++
 fs/xfs/scrub/tempexch.h |   21 +++++
 fs/xfs/scrub/tempfile.c |  194 +++++++++++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/trace.h    |    1 
 5 files changed, 228 insertions(+), 3 deletions(-)
 create mode 100644 fs/xfs/scrub/tempexch.h


diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index d9012e9a6afd2..ff156edf49a08 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -149,14 +149,15 @@ xchk_probe(
 
 /* Scrub setup and teardown */
 
+#define FSGATES_MASK	(XCHK_FSGATES_ALL | XREP_FSGATES_ALL)
 static inline void
 xchk_fsgates_disable(
 	struct xfs_scrub	*sc)
 {
-	if (!(sc->flags & XCHK_FSGATES_ALL))
+	if (!(sc->flags & FSGATES_MASK))
 		return;
 
-	trace_xchk_fsgates_disable(sc, sc->flags & XCHK_FSGATES_ALL);
+	trace_xchk_fsgates_disable(sc, sc->flags & FSGATES_MASK);
 
 	if (sc->flags & XCHK_FSGATES_DRAIN)
 		xfs_drain_wait_disable();
@@ -170,8 +171,9 @@ xchk_fsgates_disable(
 	if (sc->flags & XCHK_FSGATES_RMAP)
 		xfs_rmap_hook_disable();
 
-	sc->flags &= ~XCHK_FSGATES_ALL;
+	sc->flags &= ~FSGATES_MASK;
 }
+#undef FSGATES_MASK
 
 /* Free all the resources and finish the transactions. */
 STATIC int
diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index e37d8599718e2..aca3e652343c1 100644
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -131,6 +131,7 @@ struct xfs_scrub {
 #define XCHK_FSGATES_QUOTA	(1U << 4)  /* quota live update enabled */
 #define XCHK_FSGATES_DIRENTS	(1U << 5)  /* directory live update enabled */
 #define XCHK_FSGATES_RMAP	(1U << 6)  /* rmapbt live update enabled */
+#define XREP_FSGATES_EXCHMAPS	(1U << 29) /* uses atomic file content exchange */
 #define XREP_RESET_PERAG_RESV	(1U << 30) /* must reset AG space reservation */
 #define XREP_ALREADY_FIXED	(1U << 31) /* checking our repair work */
 
@@ -145,6 +146,12 @@ struct xfs_scrub {
 				 XCHK_FSGATES_DIRENTS | \
 				 XCHK_FSGATES_RMAP)
 
+/*
+ * The sole XREP_FSGATES* flag reflects a log intent item that is protected
+ * by a log-incompat feature flag.  No code patching in use here.
+ */
+#define XREP_FSGATES_ALL	(XREP_FSGATES_EXCHMAPS)
+
 /* Metadata scrubbers */
 int xchk_tester(struct xfs_scrub *sc);
 int xchk_superblock(struct xfs_scrub *sc);
diff --git a/fs/xfs/scrub/tempexch.h b/fs/xfs/scrub/tempexch.h
new file mode 100644
index 0000000000000..98222b684b6a0
--- /dev/null
+++ b/fs/xfs/scrub/tempexch.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022-2024 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_TEMPEXCH_H__
+#define __XFS_SCRUB_TEMPEXCH_H__
+
+#ifdef CONFIG_XFS_ONLINE_REPAIR
+struct xrep_tempexch {
+	struct xfs_exchmaps_req	req;
+};
+
+int xrep_tempexch_enable(struct xfs_scrub *sc);
+int xrep_tempexch_trans_reserve(struct xfs_scrub *sc, int whichfork,
+		struct xrep_tempexch *ti);
+
+int xrep_tempexch_contents(struct xfs_scrub *sc, struct xrep_tempexch *ti);
+#endif /* CONFIG_XFS_ONLINE_REPAIR */
+
+#endif /* __XFS_SCRUB_TEMPEXCH_H__ */
diff --git a/fs/xfs/scrub/tempfile.c b/fs/xfs/scrub/tempfile.c
index 83e683e165618..9ed750699809e 100644
--- a/fs/xfs/scrub/tempfile.c
+++ b/fs/xfs/scrub/tempfile.c
@@ -19,12 +19,14 @@
 #include "xfs_trans_space.h"
 #include "xfs_dir2.h"
 #include "xfs_exchrange.h"
+#include "xfs_exchmaps.h"
 #include "xfs_defer.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/repair.h"
 #include "scrub/trace.h"
 #include "scrub/tempfile.h"
+#include "scrub/tempexch.h"
 #include "scrub/xfile.h"
 
 /*
@@ -446,3 +448,195 @@ xrep_tempfile_roll_trans(
 	xfs_trans_ijoin(sc->tp, sc->tempip, 0);
 	return 0;
 }
+
+/* Enable atomic file content exchanges. */
+int
+xrep_tempexch_enable(
+	struct xfs_scrub	*sc)
+{
+	int			error;
+
+	if (sc->flags & XREP_FSGATES_EXCHMAPS)
+		return 0;
+
+	error = xfs_exchrange_enable(sc->mp);
+	if (error)
+		return error;
+
+	trace_xchk_fsgates_enable(sc, XREP_FSGATES_EXCHMAPS);
+
+	sc->flags |= XREP_FSGATES_EXCHMAPS;
+	return 0;
+}
+
+/*
+ * Fill out the mapping exchange request in preparation for atomically
+ * committing the contents of a metadata file that we've rebuilt in the temp
+ * file.
+ */
+STATIC int
+xrep_tempexch_prep_request(
+	struct xfs_scrub	*sc,
+	int			whichfork,
+	struct xrep_tempexch	*tx)
+{
+	struct xfs_exchmaps_req	*req = &tx->req;
+
+	memset(tx, 0, sizeof(struct xrep_tempexch));
+
+	/* COW forks don't exist on disk. */
+	if (whichfork == XFS_COW_FORK) {
+		ASSERT(0);
+		return -EINVAL;
+	}
+
+	/* Both files should have the relevant forks. */
+	if (!xfs_ifork_ptr(sc->ip, whichfork) ||
+	    !xfs_ifork_ptr(sc->tempip, whichfork)) {
+		ASSERT(xfs_ifork_ptr(sc->ip, whichfork) != NULL);
+		ASSERT(xfs_ifork_ptr(sc->tempip, whichfork) != NULL);
+		return -EINVAL;
+	}
+
+	/* Exchange all mappings in both forks. */
+	req->ip1 = sc->tempip;
+	req->ip2 = sc->ip;
+	req->startoff1 = 0;
+	req->startoff2 = 0;
+	switch (whichfork) {
+	case XFS_ATTR_FORK:
+		req->flags |= XFS_EXCHMAPS_ATTR_FORK;
+		break;
+	case XFS_DATA_FORK:
+		/* Always exchange sizes when exchanging data fork mappings. */
+		req->flags |= XFS_EXCHMAPS_SET_SIZES;
+		break;
+	}
+	req->blockcount = XFS_MAX_FILEOFF;
+
+	return 0;
+}
+
+/*
+ * Obtain a quota reservation to make sure we don't hit EDQUOT.  We can skip
+ * this if quota enforcement is disabled or if both inodes' dquots are the
+ * same.  The qretry structure must be initialized to zeroes before the first
+ * call to this function.
+ */
+STATIC int
+xrep_tempexch_reserve_quota(
+	struct xfs_scrub		*sc,
+	const struct xrep_tempexch	*tx)
+{
+	struct xfs_trans		*tp = sc->tp;
+	const struct xfs_exchmaps_req	*req = &tx->req;
+	int64_t				ddelta, rdelta;
+	int				error;
+
+	/*
+	 * Don't bother with a quota reservation if we're not enforcing them
+	 * or the two inodes have the same dquots.
+	 */
+	if (!XFS_IS_QUOTA_ON(tp->t_mountp) || req->ip1 == req->ip2 ||
+	    (req->ip1->i_udquot == req->ip2->i_udquot &&
+	     req->ip1->i_gdquot == req->ip2->i_gdquot &&
+	     req->ip1->i_pdquot == req->ip2->i_pdquot))
+		return 0;
+
+	/*
+	 * Quota reservation for each file comes from two sources.  First, we
+	 * need to account for any net gain in mapped blocks during the
+	 * exchange.  Second, we need reservation for the gross gain in mapped
+	 * blocks so that we don't trip over any quota block reservation
+	 * assertions.  We must reserve the gross gain because the quota code
+	 * subtracts from bcount the number of blocks that we unmap; it does
+	 * not add that quantity back to the quota block reservation.
+	 */
+	ddelta = max_t(int64_t, 0, req->ip2_bcount - req->ip1_bcount);
+	rdelta = max_t(int64_t, 0, req->ip2_rtbcount - req->ip1_rtbcount);
+	error = xfs_trans_reserve_quota_nblks(tp, req->ip1,
+			ddelta + req->ip1_bcount, rdelta + req->ip1_rtbcount,
+			true);
+	if (error)
+		return error;
+
+	ddelta = max_t(int64_t, 0, req->ip1_bcount - req->ip2_bcount);
+	rdelta = max_t(int64_t, 0, req->ip1_rtbcount - req->ip2_rtbcount);
+	return xfs_trans_reserve_quota_nblks(tp, req->ip2,
+			ddelta + req->ip2_bcount, rdelta + req->ip2_rtbcount,
+			true);
+}
+
+/*
+ * Prepare an existing transaction for an atomic file contents exchange.
+ *
+ * This function fills out the mapping exchange request and resource estimation
+ * structures in preparation for exchanging the contents of a metadata file
+ * that has been rebuilt in the temp file.  Next, it reserves space and quota
+ * for the transaction.
+ *
+ * The caller must hold ILOCK_EXCL of the scrub target file and the temporary
+ * file.  The caller must join both inodes to the transaction with no unlock
+ * flags, and is responsible for dropping both ILOCKs when appropriate.  Only
+ * use this when those ILOCKs cannot be dropped.
+ */
+int
+xrep_tempexch_trans_reserve(
+	struct xfs_scrub	*sc,
+	int			whichfork,
+	struct xrep_tempexch	*tx)
+{
+	int			error;
+
+	ASSERT(sc->tp != NULL);
+	ASSERT(xfs_isilocked(sc->ip, XFS_ILOCK_EXCL));
+	ASSERT(xfs_isilocked(sc->tempip, XFS_ILOCK_EXCL));
+
+	error = xrep_tempexch_prep_request(sc, whichfork, tx);
+	if (error)
+		return error;
+
+	error = xfs_exchmaps_estimate(&tx->req);
+	if (error)
+		return error;
+
+	error = xfs_trans_reserve_more(sc->tp, tx->req.resblks, 0);
+	if (error)
+		return error;
+
+	return xrep_tempexch_reserve_quota(sc, tx);
+}
+
+/*
+ * Exchange file mappings (and hence file contents) between the file being
+ * repaired and the temporary file.  Returns with both inodes locked and joined
+ * to a clean scrub transaction.
+ */
+int
+xrep_tempexch_contents(
+	struct xfs_scrub	*sc,
+	struct xrep_tempexch	*tx)
+{
+	int			error;
+
+	ASSERT(sc->flags & XREP_FSGATES_EXCHMAPS);
+
+	xfs_exchange_mappings(sc->tp, &tx->req);
+	error = xfs_defer_finish(&sc->tp);
+	if (error)
+		return error;
+
+	/*
+	 * If we exchanged the ondisk sizes of two metadata files, we must
+	 * exchanged the incore sizes as well.
+	 */
+	if (tx->req.flags & XFS_EXCHMAPS_SET_SIZES) {
+		loff_t	temp;
+
+		temp = i_size_read(VFS_I(sc->ip));
+		i_size_write(VFS_I(sc->ip), i_size_read(VFS_I(sc->tempip)));
+		i_size_write(VFS_I(sc->tempip), temp);
+	}
+
+	return 0;
+}
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index 50801d5914839..5edbabacc31a8 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -114,6 +114,7 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_HEALTHY);
 	{ XCHK_FSGATES_QUOTA,			"fsgates_quota" }, \
 	{ XCHK_FSGATES_DIRENTS,			"fsgates_dirents" }, \
 	{ XCHK_FSGATES_RMAP,			"fsgates_rmap" }, \
+	{ XREP_FSGATES_EXCHMAPS,		"fsgates_exchmaps" }, \
 	{ XREP_RESET_PERAG_RESV,		"reset_perag_resv" }, \
 	{ XREP_ALREADY_FIXED,			"already_fixed" }
 


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* Re: [PATCH 2/3] xfs: teach the tempfile to set up atomic file content exchanges
  2024-02-27  2:26 ` [PATCH 2/3] xfs: teach the tempfile to set up atomic file content exchanges Darrick J. Wong
@ 2024-02-27 18:18   ` Christoph Hellwig
  0 siblings, 0 replies; 12+ messages in thread
From: Christoph Hellwig @ 2024-02-27 18:18 UTC (permalink / raw)
  To: Darrick J. Wong; +Cc: linux-xfs

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>


^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 3/3] xfs: online repair of realtime summaries
  2024-02-27  2:18 [PATCHSET v29.4 05/13] xfs: online repair of realtime summaries Darrick J. Wong
  2024-02-27  2:25 ` [PATCH 1/3] xfs: support preallocating and copying content into temporary files Darrick J. Wong
  2024-02-27  2:26 ` [PATCH 2/3] xfs: teach the tempfile to set up atomic file content exchanges Darrick J. Wong
@ 2024-02-27  2:26 ` Darrick J. Wong
  2024-02-27 18:19   ` Christoph Hellwig
  2 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2024-02-27  2:26 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

From: Darrick J. Wong <djwong@kernel.org>

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 1ea7cacd92a7c..66415ac8f5717 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 abff79a77c72b..4afaa0a0760c6 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_exchmaps.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 ce082d941459f..0e2b695ab8f66 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 5055092bd9e85..3fee603f52441 100644
--- a/fs/xfs/scrub/rtsummary.c
+++ b/fs/xfs/scrub/rtsummary.c
@@ -17,10 +17,14 @@
 #include "xfs_bit.h"
 #include "xfs_bmap.h"
 #include "xfs_sb.h"
+#include "xfs_exchmaps.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
 #include "scrub/xfile.h"
+#include "scrub/repair.h"
+#include "scrub/tempexch.h"
+#include "scrub/rtsummary.h"
 
 /*
  * Realtime Summary
@@ -32,18 +36,6 @@
  * (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(
@@ -60,6 +52,12 @@ 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.
@@ -70,7 +68,7 @@ xchk_setup_rtsummary(
 	if (error)
 		return error;
 
-	error = xchk_trans_alloc(sc, 0);
+	error = xchk_trans_alloc(sc, rts->resblks);
 	if (error)
 		return error;
 
@@ -135,7 +133,7 @@ xfsum_store(
 			sumoff << XFS_WORDLOG);
 }
 
-static inline int
+inline int
 xfsum_copyout(
 	struct xfs_scrub	*sc,
 	xfs_rtsumoff_t		sumoff,
@@ -362,7 +360,12 @@ 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..e1d50304d8d48
--- /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_tempexch	tempexch;
+#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..c8bb6c4f15d05
--- /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_exchmaps.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/tempexch.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 exchanging
+	 * the extent mappings.
+	 *
+	 * We cannot use xfs_exchmaps_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 file content exchanges before we allocate
+	 * any transactions or grab ILOCKs.
+	 */
+	return xrep_tempexch_enable(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 exchange the contents.  Nothing in repair uses the temporary
+	 * buffer, so we can reuse it for the tempfile exchrange information.
+	 */
+	error = xrep_tempexch_trans_reserve(sc, XFS_DATA_FORK, &rts->tempexch);
+	if (error)
+		return error;
+
+	error = xrep_tempexch_contents(sc, &rts->tempexch);
+	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 ff156edf49a08..62a064c1a5d34 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -18,6 +18,7 @@
 #include "xfs_buf_mem.h"
 #include "xfs_rmap.h"
 #include "xfs_exchrange.h"
+#include "xfs_exchmaps.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
@@ -354,7 +355,7 @@ 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,


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* Re: [PATCH 3/3] xfs: online repair of realtime summaries
  2024-02-27  2:26 ` [PATCH 3/3] xfs: online repair of realtime summaries Darrick J. Wong
@ 2024-02-27 18:19   ` Christoph Hellwig
  0 siblings, 0 replies; 12+ messages in thread
From: Christoph Hellwig @ 2024-02-27 18:19 UTC (permalink / raw)
  To: Darrick J. Wong; +Cc: linux-xfs

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCHSET v30.3 05/16] xfs: online repair of realtime summaries
@ 2024-04-15 23:34 Darrick J. Wong
  2024-04-15 23:46 ` [PATCH 3/3] " Darrick J. Wong
  0 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2024-04-15 23:34 UTC (permalink / raw)
  To: chandanbabu, djwong; +Cc: Christoph Hellwig, linux-xfs

Hi all,

We now have all the infrastructure we need to repair file metadata.
We'll begin with the realtime summary file, because it is the least
complex data structure.  To support this we need to add three more
pieces to the temporary file code from the previous patchset --
preallocating space in the temp file, formatting metadata into that
space and writing the blocks to disk, and swapping the fork mappings
atomically.

After that, the actual reconstruction of the realtime summary
information is pretty simple, since we can simply write the incore
copy computed by the rtsummary scrubber to the temporary file, swap the
contents, and reap the old blocks.

If you're going to start using this code, I strongly recommend pulling
from my git trees, which are linked below.

This has been running on the djcloud for months with no problems.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-rtsummary-6.10
---
Commits in this patchset:
 * xfs: support preallocating and copying content into temporary files
 * xfs: teach the tempfile to set up atomic file content exchanges
 * xfs: online repair of realtime summaries
---
 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            |   11 +
 fs/xfs/scrub/scrub.h            |    7 +
 fs/xfs/scrub/tempexch.h         |   21 ++
 fs/xfs/scrub/tempfile.c         |  388 +++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/tempfile.h         |   15 ++
 fs/xfs/scrub/trace.h            |   40 ++++
 12 files changed, 715 insertions(+), 19 deletions(-)
 create mode 100644 fs/xfs/scrub/rtsummary.h
 create mode 100644 fs/xfs/scrub/rtsummary_repair.c
 create mode 100644 fs/xfs/scrub/tempexch.h

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 3/3] xfs: online repair of realtime summaries
  2024-04-15 23:34 [PATCHSET v30.3 05/16] " Darrick J. Wong
@ 2024-04-15 23:46 ` Darrick J. Wong
  0 siblings, 0 replies; 12+ messages in thread
From: Darrick J. Wong @ 2024-04-15 23:46 UTC (permalink / raw)
  To: chandanbabu, djwong; +Cc: Christoph Hellwig, linux-xfs

From: Darrick J. Wong <djwong@kernel.org>

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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 ae8488ab4d6b..5e3ac7ec8fa5 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -212,6 +212,7 @@ 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 a27d33b6f464..a2da2bef509a 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_exchmaps.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 ce082d941459..0e2b695ab8f6 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 5055092bd9e8..3fee603f5244 100644
--- a/fs/xfs/scrub/rtsummary.c
+++ b/fs/xfs/scrub/rtsummary.c
@@ -17,10 +17,14 @@
 #include "xfs_bit.h"
 #include "xfs_bmap.h"
 #include "xfs_sb.h"
+#include "xfs_exchmaps.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
 #include "scrub/xfile.h"
+#include "scrub/repair.h"
+#include "scrub/tempexch.h"
+#include "scrub/rtsummary.h"
 
 /*
  * Realtime Summary
@@ -32,18 +36,6 @@
  * (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(
@@ -60,6 +52,12 @@ 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.
@@ -70,7 +68,7 @@ xchk_setup_rtsummary(
 	if (error)
 		return error;
 
-	error = xchk_trans_alloc(sc, 0);
+	error = xchk_trans_alloc(sc, rts->resblks);
 	if (error)
 		return error;
 
@@ -135,7 +133,7 @@ xfsum_store(
 			sumoff << XFS_WORDLOG);
 }
 
-static inline int
+inline int
 xfsum_copyout(
 	struct xfs_scrub	*sc,
 	xfs_rtsumoff_t		sumoff,
@@ -362,7 +360,12 @@ 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 000000000000..e1d50304d8d4
--- /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_tempexch	tempexch;
+#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 000000000000..c8bb6c4f15d0
--- /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_exchmaps.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/tempexch.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 exchanging
+	 * the extent mappings.
+	 *
+	 * We cannot use xfs_exchmaps_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 file content exchanges before we allocate
+	 * any transactions or grab ILOCKs.
+	 */
+	return xrep_tempexch_enable(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 exchange the contents.  Nothing in repair uses the temporary
+	 * buffer, so we can reuse it for the tempfile exchrange information.
+	 */
+	error = xrep_tempexch_trans_reserve(sc, XFS_DATA_FORK, &rts->tempexch);
+	if (error)
+		return error;
+
+	error = xrep_tempexch_contents(sc, &rts->tempexch);
+	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 ff156edf49a0..62a064c1a5d3 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -18,6 +18,7 @@
 #include "xfs_buf_mem.h"
 #include "xfs_rmap.h"
 #include "xfs_exchrange.h"
+#include "xfs_exchmaps.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
@@ -354,7 +355,7 @@ 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,


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCHSET v30.1 06/15] xfs: online repair of realtime summaries
@ 2024-03-27  1:47 Darrick J. Wong
  2024-03-27  1:58 ` [PATCH 3/3] " Darrick J. Wong
  0 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2024-03-27  1:47 UTC (permalink / raw)
  To: djwong; +Cc: Christoph Hellwig, linux-xfs

Hi all,

We now have all the infrastructure we need to repair file metadata.
We'll begin with the realtime summary file, because it is the least
complex data structure.  To support this we need to add three more
pieces to the temporary file code from the previous patchset --
preallocating space in the temp file, formatting metadata into that
space and writing the blocks to disk, and swapping the fork mappings
atomically.

After that, the actual reconstruction of the realtime summary
information is pretty simple, since we can simply write the incore
copy computed by the rtsummary scrubber to the temporary file, swap the
contents, and reap the old blocks.

If you're going to start using this code, I strongly recommend pulling
from my git trees, which are linked below.

This has been running on the djcloud for months with no problems.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-rtsummary

xfsprogs git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=repair-rtsummary

fstests git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=repair-rtsummary
---
Commits in this patchset:
 * xfs: support preallocating and copying content into temporary files
 * xfs: teach the tempfile to set up atomic file content exchanges
 * xfs: online repair of realtime summaries
---
 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            |   11 +
 fs/xfs/scrub/scrub.h            |    7 +
 fs/xfs/scrub/tempexch.h         |   21 ++
 fs/xfs/scrub/tempfile.c         |  391 +++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/tempfile.h         |   15 +
 fs/xfs/scrub/trace.h            |   40 ++++
 12 files changed, 718 insertions(+), 19 deletions(-)
 create mode 100644 fs/xfs/scrub/rtsummary.h
 create mode 100644 fs/xfs/scrub/rtsummary_repair.c
 create mode 100644 fs/xfs/scrub/tempexch.h

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 3/3] xfs: online repair of realtime summaries
  2024-03-27  1:47 [PATCHSET v30.1 06/15] " Darrick J. Wong
@ 2024-03-27  1:58 ` Darrick J. Wong
  0 siblings, 0 replies; 12+ messages in thread
From: Darrick J. Wong @ 2024-03-27  1:58 UTC (permalink / raw)
  To: djwong; +Cc: Christoph Hellwig, linux-xfs

From: Darrick J. Wong <djwong@kernel.org>

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 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 ae8488ab4d6b5..5e3ac7ec8fa5b 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -212,6 +212,7 @@ 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 abff79a77c72b..4afaa0a0760c6 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_exchmaps.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 ce082d941459f..0e2b695ab8f66 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 5055092bd9e85..3fee603f52441 100644
--- a/fs/xfs/scrub/rtsummary.c
+++ b/fs/xfs/scrub/rtsummary.c
@@ -17,10 +17,14 @@
 #include "xfs_bit.h"
 #include "xfs_bmap.h"
 #include "xfs_sb.h"
+#include "xfs_exchmaps.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
 #include "scrub/xfile.h"
+#include "scrub/repair.h"
+#include "scrub/tempexch.h"
+#include "scrub/rtsummary.h"
 
 /*
  * Realtime Summary
@@ -32,18 +36,6 @@
  * (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(
@@ -60,6 +52,12 @@ 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.
@@ -70,7 +68,7 @@ xchk_setup_rtsummary(
 	if (error)
 		return error;
 
-	error = xchk_trans_alloc(sc, 0);
+	error = xchk_trans_alloc(sc, rts->resblks);
 	if (error)
 		return error;
 
@@ -135,7 +133,7 @@ xfsum_store(
 			sumoff << XFS_WORDLOG);
 }
 
-static inline int
+inline int
 xfsum_copyout(
 	struct xfs_scrub	*sc,
 	xfs_rtsumoff_t		sumoff,
@@ -362,7 +360,12 @@ 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..e1d50304d8d48
--- /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_tempexch	tempexch;
+#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..c8bb6c4f15d05
--- /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_exchmaps.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/tempexch.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 exchanging
+	 * the extent mappings.
+	 *
+	 * We cannot use xfs_exchmaps_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 file content exchanges before we allocate
+	 * any transactions or grab ILOCKs.
+	 */
+	return xrep_tempexch_enable(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 exchange the contents.  Nothing in repair uses the temporary
+	 * buffer, so we can reuse it for the tempfile exchrange information.
+	 */
+	error = xrep_tempexch_trans_reserve(sc, XFS_DATA_FORK, &rts->tempexch);
+	if (error)
+		return error;
+
+	error = xrep_tempexch_contents(sc, &rts->tempexch);
+	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 ff156edf49a08..62a064c1a5d34 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -18,6 +18,7 @@
 #include "xfs_buf_mem.h"
 #include "xfs_rmap.h"
 #include "xfs_exchrange.h"
+#include "xfs_exchmaps.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
@@ -354,7 +355,7 @@ 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,


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCHSET v29.0 18/28] xfs: online repair of realtime summaries
@ 2023-12-31 19:30 Darrick J. Wong
  2023-12-31 20:32 ` [PATCH 3/3] " Darrick J. Wong
  0 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2023-12-31 19:30 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

Hi all,

We now have all the infrastructure we need to repair file metadata.
We'll begin with the realtime summary file, because it is the least
complex data structure.  To support this we need to add three more
pieces to the temporary file code from the previous patchset --
preallocating space in the temp file, formatting metadata into that
space and writing the blocks to disk, and swapping the fork mappings
atomically.

After that, the actual reconstruction of the realtime summary
information is pretty simple, since we can simply write the incore
copy computed by the rtsummary scrubber to the temporary file, swap the
contents, and reap the old blocks.

If you're going to start using this code, I strongly recommend pulling
from my git trees, which are linked below.

This has been running on the djcloud for months with no problems.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-rtsummary

xfsprogs git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=repair-rtsummary

fstests git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=repair-rtsummary
---
 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            |   14 +
 fs/xfs/scrub/scrub.h            |    7 +
 fs/xfs/scrub/tempfile.c         |  401 +++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/tempfile.h         |   15 +
 fs/xfs/scrub/tempswap.h         |   21 ++
 fs/xfs/scrub/trace.h            |   40 ++++
 12 files changed, 731 insertions(+), 19 deletions(-)
 create mode 100644 fs/xfs/scrub/rtsummary.h
 create mode 100644 fs/xfs/scrub/rtsummary_repair.c
 create mode 100644 fs/xfs/scrub/tempswap.h

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 3/3] xfs: online repair of realtime summaries
  2023-12-31 19:30 [PATCHSET v29.0 18/28] " Darrick J. Wong
@ 2023-12-31 20:32 ` Darrick J. Wong
  0 siblings, 0 replies; 12+ messages in thread
From: Darrick J. Wong @ 2023-12-31 20:32 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

From: Darrick J. Wong <djwong@kernel.org>

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,


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCHSET v25.0 0/3] xfs: online repair of realtime summaries
@ 2023-05-26  0:35 Darrick J. Wong
  2023-05-26  1:30 ` [PATCH 3/3] " Darrick J. Wong
  0 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2023-05-26  0:35 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

Hi all,

We now have all the infrastructure we need to repair file metadata.
We'll begin with the realtime summary file, because it is the least
complex data structure.  To support this we need to add three more
pieces to the temporary file code from the previous patchset --
preallocating space in the temp file, formatting metadata into that
space and writing the blocks to disk, and swapping the fork mappings
atomically.

After that, the actual reconstruction of the realtime summary
information is pretty simple, since we can simply write the incore
copy computed by the rtsummary scrubber to the temporary file, swap the
contents, and reap the old blocks.

If you're going to start using this mess, you probably ought to just
pull from my git trees, which are linked below.

This is an extraordinary way to destroy everything.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-rtsummary

xfsprogs git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=repair-rtsummary

fstests git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=repair-rtsummary
---
 fs/xfs/Makefile                 |    1 
 fs/xfs/scrub/common.c           |    1 
 fs/xfs/scrub/repair.h           |   14 +
 fs/xfs/scrub/rtsummary.c        |   18 +-
 fs/xfs/scrub/rtsummary.h        |   14 +
 fs/xfs/scrub/rtsummary_repair.c |  169 +++++++++++++++++
 fs/xfs/scrub/scrub.c            |   14 +
 fs/xfs/scrub/scrub.h            |    7 +
 fs/xfs/scrub/tempfile.c         |  392 +++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/tempfile.h         |   15 +
 fs/xfs/scrub/tempswap.h         |   21 ++
 fs/xfs/scrub/trace.h            |   40 ++++
 12 files changed, 697 insertions(+), 9 deletions(-)
 create mode 100644 fs/xfs/scrub/rtsummary.h
 create mode 100644 fs/xfs/scrub/rtsummary_repair.c
 create mode 100644 fs/xfs/scrub/tempswap.h

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 3/3] xfs: online repair of realtime summaries
  2023-05-26  0:35 [PATCHSET v25.0 0/3] " Darrick J. Wong
@ 2023-05-26  1:30 ` Darrick J. Wong
  0 siblings, 0 replies; 12+ messages in thread
From: Darrick J. Wong @ 2023-05-26  1:30 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

From: Darrick J. Wong <djwong@kernel.org>

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           |   14 +++
 fs/xfs/scrub/rtsummary.c        |   18 +++-
 fs/xfs/scrub/rtsummary.h        |   14 +++
 fs/xfs/scrub/rtsummary_repair.c |  169 +++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/scrub.c            |    3 -
 7 files changed, 214 insertions(+), 6 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 3f0b2bd87f7d..9e3d2fdfb9d7 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -209,6 +209,7 @@ 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 6f505e9fb07f..bdb4089911d8 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -32,6 +32,7 @@
 #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 c289855c615d..2af25ad31fc7 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -81,6 +81,8 @@ int xrep_metadata_inode_forks(struct xfs_scrub *sc);
 bool xrep_set_nlink(struct xfs_inode *ip, uint64_t nlink);
 int xrep_setup_ag_rmapbt(struct xfs_scrub *sc);
 int xrep_setup_ag_refcountbt(struct xfs_scrub *sc);
+int xrep_setup_rtsummary(struct xfs_scrub *sc, unsigned int *resblks,
+		size_t *bufsize);
 
 /* Repair setup functions */
 int xrep_setup_ag_allocbt(struct xfs_scrub *sc);
@@ -118,8 +120,10 @@ 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
@@ -187,6 +191,15 @@ static inline int xrep_setup_rtbitmap(struct xfs_scrub *sc, unsigned int *x)
 	return 0;
 }
 
+static inline int
+xrep_setup_rtsummary(
+	struct xfs_scrub	*sc,
+	unsigned int		*whatever,
+	size_t			*dontcare)
+{
+	return 0;
+}
+
 #define xrep_revalidate_allocbt		(NULL)
 #define xrep_revalidate_iallocbt	(NULL)
 
@@ -208,6 +221,7 @@ static inline int xrep_setup_rtbitmap(struct xfs_scrub *sc, unsigned int *x)
 #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 9da732698d2e..fc8a93c3a26b 100644
--- a/fs/xfs/scrub/rtsummary.c
+++ b/fs/xfs/scrub/rtsummary.c
@@ -20,6 +20,8 @@
 #include "scrub/common.h"
 #include "scrub/trace.h"
 #include "scrub/xfile.h"
+#include "scrub/repair.h"
+#include "scrub/rtsummary.h"
 
 /*
  * Realtime Summary
@@ -37,8 +39,16 @@ xchk_setup_rtsummary(
 	struct xfs_scrub	*sc)
 {
 	struct xfs_mount	*mp = sc->mp;
+	size_t			bufsize = mp->m_sb.sb_blocksize;
+	unsigned int		resblks = 0;
 	int			error;
 
+	if (xchk_could_repair(sc)) {
+		error = xrep_setup_rtsummary(sc, &resblks, &bufsize);
+		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.
@@ -48,12 +58,12 @@ xchk_setup_rtsummary(
 	if (error)
 		return error;
 
-	error = xchk_trans_alloc(sc, 0);
+	error = xchk_trans_alloc(sc, resblks);
 	if (error)
 		return error;
 
 	/* Allocate a memory buffer for the summary comparison. */
-	sc->buf = kvmalloc(mp->m_sb.sb_blocksize, XCHK_GFP_FLAGS);
+	sc->buf = kvmalloc(bufsize, XCHK_GFP_FLAGS);
 	if (!sc->buf)
 		return -ENOMEM;
 
@@ -78,8 +88,6 @@ xchk_setup_rtsummary(
 
 /* Helper functions to record suminfo words in an xfile. */
 
-typedef unsigned int xchk_rtsumoff_t;
-
 static inline int
 xfsum_load(
 	struct xfs_scrub	*sc,
@@ -100,7 +108,7 @@ xfsum_store(
 			sumoff << XFS_WORDLOG);
 }
 
-static inline int
+inline int
 xfsum_copyout(
 	struct xfs_scrub	*sc,
 	xchk_rtsumoff_t		sumoff,
diff --git a/fs/xfs/scrub/rtsummary.h b/fs/xfs/scrub/rtsummary.h
new file mode 100644
index 000000000000..8c61fda80830
--- /dev/null
+++ b/fs/xfs/scrub/rtsummary.h
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020-2023 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_RTSUMMARY_H__
+#define __XFS_SCRUB_RTSUMMARY_H__
+
+typedef unsigned int xchk_rtsumoff_t;
+
+int xfsum_copyout(struct xfs_scrub *sc, xchk_rtsumoff_t sumoff,
+		xfs_suminfo_t *info, unsigned int nr_words);
+
+#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 000000000000..28527454d67a
--- /dev/null
+++ b/fs/xfs/scrub/rtsummary_repair.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020-2023 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_rtalloc.h"
+#include "xfs_inode.h"
+#include "xfs_bit.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_swapext.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"
+
+struct xrep_rtsummary {
+	/* suminfo position of xfile as we write buffers to disk. */
+	xchk_rtsumoff_t		prep_wordoff;
+};
+
+/* Set us up to repair the rtsummary file. */
+int
+xrep_setup_rtsummary(
+	struct xfs_scrub	*sc,
+	unsigned int		*resblks,
+	size_t			*bufsize)
+{
+	struct xfs_mount	*mp = sc->mp;
+	unsigned long long	blocks;
+	int			error;
+
+	*bufsize = max(*bufsize, sizeof(struct xrep_tempswap));
+
+	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;
+
+	*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 xrep_rtsummary	*rs = data;
+	struct xfs_mount	*mp = sc->mp;
+	int			error;
+
+	bp->b_ops = &xfs_rtbuf_ops;
+
+	error = xfsum_copyout(sc, rs->prep_wordoff, bp->b_addr,
+			mp->m_blockwsize);
+	if (error)
+		return error;
+
+	rs->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 xrep_rtsummary	rs = { .prep_wordoff = 0, };
+	struct xrep_tempswap	*ti = NULL;
+	xfs_filblks_t		rsumblocks;
+	int			error;
+
+	/* We require the rmapbt to rebuild anything. */
+	if (!xfs_has_rmapbt(sc->mp))
+		return -EOPNOTSUPP;
+
+	/* 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(sc->mp, sc->mp->m_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, &rs);
+	if (error)
+		return error;
+	error = xrep_tempfile_set_isize(sc, sc->mp->m_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.
+	 */
+	ti = sc->buf;
+	error = xrep_tempswap_trans_reserve(sc, XFS_DATA_FORK, ti);
+	if (error)
+		return error;
+
+	error = xrep_tempswap_contents(sc, ti);
+	if (error)
+		return error;
+	ti = NULL;
+
+	/* 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 0bfa9a076582..17d93bea6d64 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -20,6 +20,7 @@
 #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"
@@ -360,7 +361,7 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
 		.setup	= xchk_setup_rtsummary,
 		.scrub	= xchk_rtsummary,
 		.has	= xfs_has_realtime,
-		.repair	= xrep_notsupported,
+		.repair	= xrep_rtsummary,
 	},
 	[XFS_SCRUB_TYPE_UQUOTA] = {	/* user quota */
 		.type	= ST_FS,


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCHSET v24.0 0/3] xfs: online repair of realtime summaries
@ 2022-12-30 22:14 Darrick J. Wong
  2022-12-30 22:14 ` [PATCH 3/3] " Darrick J. Wong
  0 siblings, 1 reply; 12+ messages in thread
From: Darrick J. Wong @ 2022-12-30 22:14 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

Hi all,

We now have all the infrastructure we need to repair file metadata.
We'll begin with the realtime summary file, because it is the least
complex data structure.  To support this we need to add three more
pieces to the temporary file code from the previous patchset --
preallocating space in the temp file, formatting metadata into that
space and writing the blocks to disk, and swapping the fork mappings
atomically.

After that, the actual reconstruction of the realtime summary
information is pretty simple, since we can simply write the incore
copy computed by the rtsummary scrubber to the temporary file, swap the
contents, and reap the old blocks.

If you're going to start using this mess, you probably ought to just
pull from my git trees, which are linked below.

This is an extraordinary way to destroy everything.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-rtsummary

xfsprogs git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=repair-rtsummary

fstests git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=repair-rtsummary
---
 fs/xfs/Makefile                 |    1 
 fs/xfs/scrub/common.c           |    1 
 fs/xfs/scrub/repair.h           |   14 +
 fs/xfs/scrub/rtsummary.c        |   18 +-
 fs/xfs/scrub/rtsummary.h        |   14 +
 fs/xfs/scrub/rtsummary_repair.c |  169 +++++++++++++++++
 fs/xfs/scrub/scrub.c            |    7 +
 fs/xfs/scrub/scrub.h            |    1 
 fs/xfs/scrub/tempfile.c         |  388 +++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/tempfile.h         |   15 ++
 fs/xfs/scrub/tempswap.h         |   21 ++
 fs/xfs/scrub/trace.h            |   40 ++++
 12 files changed, 683 insertions(+), 6 deletions(-)
 create mode 100644 fs/xfs/scrub/rtsummary.h
 create mode 100644 fs/xfs/scrub/rtsummary_repair.c
 create mode 100644 fs/xfs/scrub/tempswap.h

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 3/3] xfs: online repair of realtime summaries
  2022-12-30 22:14 [PATCHSET v24.0 0/3] " Darrick J. Wong
@ 2022-12-30 22:14 ` Darrick J. Wong
  0 siblings, 0 replies; 12+ messages in thread
From: Darrick J. Wong @ 2022-12-30 22:14 UTC (permalink / raw)
  To: djwong; +Cc: linux-xfs

From: Darrick J. Wong <djwong@kernel.org>

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           |   14 +++
 fs/xfs/scrub/rtsummary.c        |   18 +++-
 fs/xfs/scrub/rtsummary.h        |   14 +++
 fs/xfs/scrub/rtsummary_repair.c |  169 +++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/scrub.c            |    3 -
 7 files changed, 214 insertions(+), 6 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 6df1cd3b46ca..0abdcc69cd7f 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -207,6 +207,7 @@ 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 7eade2567af6..2fbd8aa01ef7 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -32,6 +32,7 @@
 #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 3b25f2fa629e..086e8e739264 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -80,6 +80,8 @@ int xrep_bmap(struct xfs_scrub *sc, int whichfork, bool allow_unwritten);
 int xrep_metadata_inode_forks(struct xfs_scrub *sc);
 int xrep_setup_ag_rmapbt(struct xfs_scrub *sc);
 int xrep_setup_ag_refcountbt(struct xfs_scrub *sc);
+int xrep_setup_rtsummary(struct xfs_scrub *sc, unsigned int *resblks,
+		size_t *bufsize);
 
 /* Repair setup functions */
 int xrep_setup_ag_allocbt(struct xfs_scrub *sc);
@@ -117,8 +119,10 @@ 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
@@ -186,6 +190,15 @@ static inline int xrep_setup_rtbitmap(struct xfs_scrub *sc, unsigned int *x)
 	return 0;
 }
 
+static inline int
+xrep_setup_rtsummary(
+	struct xfs_scrub	*sc,
+	unsigned int		*whatever,
+	size_t			*dontcare)
+{
+	return 0;
+}
+
 #define xrep_revalidate_allocbt		(NULL)
 #define xrep_revalidate_iallocbt	(NULL)
 
@@ -207,6 +220,7 @@ static inline int xrep_setup_rtbitmap(struct xfs_scrub *sc, unsigned int *x)
 #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 73c75d41ef3c..7d1bc49fb3dd 100644
--- a/fs/xfs/scrub/rtsummary.c
+++ b/fs/xfs/scrub/rtsummary.c
@@ -20,6 +20,8 @@
 #include "scrub/common.h"
 #include "scrub/trace.h"
 #include "scrub/xfile.h"
+#include "scrub/repair.h"
+#include "scrub/rtsummary.h"
 
 /*
  * Realtime Summary
@@ -37,8 +39,16 @@ xchk_setup_rtsummary(
 	struct xfs_scrub	*sc)
 {
 	struct xfs_mount	*mp = sc->mp;
+	size_t			bufsize = mp->m_sb.sb_blocksize;
+	unsigned int		resblks = 0;
 	int			error;
 
+	if (xchk_could_repair(sc)) {
+		error = xrep_setup_rtsummary(sc, &resblks, &bufsize);
+		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.
@@ -48,12 +58,12 @@ xchk_setup_rtsummary(
 	if (error)
 		return error;
 
-	error = xchk_trans_alloc(sc, 0);
+	error = xchk_trans_alloc(sc, resblks);
 	if (error)
 		return error;
 
 	/* Allocate a memory buffer for the summary comparison. */
-	sc->buf = kvmalloc(mp->m_sb.sb_blocksize, XCHK_GFP_FLAGS);
+	sc->buf = kvmalloc(bufsize, XCHK_GFP_FLAGS);
 	if (!sc->buf)
 		return -ENOMEM;
 
@@ -78,8 +88,6 @@ xchk_setup_rtsummary(
 
 /* Helper functions to record suminfo words in an xfile. */
 
-typedef unsigned int xchk_rtsumoff_t;
-
 static inline int
 xfsum_load(
 	struct xfs_scrub	*sc,
@@ -100,7 +108,7 @@ xfsum_store(
 			sumoff << XFS_WORDLOG);
 }
 
-static inline int
+inline int
 xfsum_copyout(
 	struct xfs_scrub	*sc,
 	xchk_rtsumoff_t		sumoff,
diff --git a/fs/xfs/scrub/rtsummary.h b/fs/xfs/scrub/rtsummary.h
new file mode 100644
index 000000000000..e5f3c69c4cbf
--- /dev/null
+++ b/fs/xfs/scrub/rtsummary.h
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2022 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_RTSUMMARY_H__
+#define __XFS_SCRUB_RTSUMMARY_H__
+
+typedef unsigned int xchk_rtsumoff_t;
+
+int xfsum_copyout(struct xfs_scrub *sc, xchk_rtsumoff_t sumoff,
+		xfs_suminfo_t *info, unsigned int nr_words);
+
+#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 000000000000..f5c14c50ebf3
--- /dev/null
+++ b/fs/xfs/scrub/rtsummary_repair.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2022 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 "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"
+
+struct xrep_rtsummary {
+	/* suminfo position of xfile as we write buffers to disk. */
+	xchk_rtsumoff_t		prep_wordoff;
+};
+
+/* Set us up to repair the rtsummary file. */
+int
+xrep_setup_rtsummary(
+	struct xfs_scrub	*sc,
+	unsigned int		*resblks,
+	size_t			*bufsize)
+{
+	struct xfs_mount	*mp = sc->mp;
+	unsigned long long	blocks;
+	int			error;
+
+	*bufsize = max(*bufsize, sizeof(struct xrep_tempswap));
+
+	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;
+
+	*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 xrep_rtsummary	*rs = data;
+	struct xfs_mount	*mp = sc->mp;
+	int			error;
+
+	bp->b_ops = &xfs_rtbuf_ops;
+
+	error = xfsum_copyout(sc, rs->prep_wordoff, bp->b_addr,
+			mp->m_blockwsize);
+	if (error)
+		return error;
+
+	rs->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 xrep_rtsummary	rs = { .prep_wordoff = 0, };
+	struct xrep_tempswap	*ti = NULL;
+	xfs_filblks_t		rsumblocks;
+	int			error;
+
+	/* We require the rmapbt to rebuild anything. */
+	if (!xfs_has_rmapbt(sc->mp))
+		return -EOPNOTSUPP;
+
+	/* 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(sc->mp, sc->mp->m_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, &rs);
+	if (error)
+		return error;
+	error = xrep_tempfile_set_isize(sc, sc->mp->m_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.
+	 */
+	ti = sc->buf;
+	error = xrep_tempswap_trans_reserve(sc, XFS_DATA_FORK, ti);
+	if (error)
+		return error;
+
+	error = xrep_tempswap_contents(sc, ti);
+	if (error)
+		return error;
+	ti = NULL;
+
+	/* 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 a994710d99ae..a9030603b424 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -19,6 +19,7 @@
 #include "xfs_btree_staging.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"
@@ -358,7 +359,7 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
 		.setup	= xchk_setup_rtsummary,
 		.scrub	= xchk_rtsummary,
 		.has	= xfs_has_realtime,
-		.repair	= xrep_notsupported,
+		.repair	= xrep_rtsummary,
 	},
 	[XFS_SCRUB_TYPE_UQUOTA] = {	/* user quota */
 		.type	= ST_FS,


^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2024-04-15 23:46 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-02-27  2:18 [PATCHSET v29.4 05/13] xfs: online repair of realtime summaries Darrick J. Wong
2024-02-27  2:25 ` [PATCH 1/3] xfs: support preallocating and copying content into temporary files Darrick J. Wong
2024-02-27 18:17   ` Christoph Hellwig
2024-02-27  2:26 ` [PATCH 2/3] xfs: teach the tempfile to set up atomic file content exchanges Darrick J. Wong
2024-02-27 18:18   ` Christoph Hellwig
2024-02-27  2:26 ` [PATCH 3/3] xfs: online repair of realtime summaries Darrick J. Wong
2024-02-27 18:19   ` Christoph Hellwig
  -- strict thread matches above, loose matches on Subject: below --
2024-04-15 23:34 [PATCHSET v30.3 05/16] " Darrick J. Wong
2024-04-15 23:46 ` [PATCH 3/3] " Darrick J. Wong
2024-03-27  1:47 [PATCHSET v30.1 06/15] " Darrick J. Wong
2024-03-27  1:58 ` [PATCH 3/3] " Darrick J. Wong
2023-12-31 19:30 [PATCHSET v29.0 18/28] " Darrick J. Wong
2023-12-31 20:32 ` [PATCH 3/3] " Darrick J. Wong
2023-05-26  0:35 [PATCHSET v25.0 0/3] " Darrick J. Wong
2023-05-26  1:30 ` [PATCH 3/3] " Darrick J. Wong
2022-12-30 22:14 [PATCHSET v24.0 0/3] " Darrick J. Wong
2022-12-30 22:14 ` [PATCH 3/3] " Darrick J. Wong

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