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-rw-r--r--fs/xfs/scrub/rtsummary.c264
1 files changed, 264 insertions, 0 deletions
diff --git a/fs/xfs/scrub/rtsummary.c b/fs/xfs/scrub/rtsummary.c
new file mode 100644
index 000000000000..437ed9acbb27
--- /dev/null
+++ b/fs/xfs/scrub/rtsummary.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2017-2023 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_btree.h"
+#include "xfs_inode.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_rtalloc.h"
+#include "xfs_bit.h"
+#include "xfs_bmap.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/xfile.h"
+
+/*
+ * Realtime Summary
+ * ================
+ *
+ * We check the realtime summary by scanning the realtime bitmap file to create
+ * a new summary file incore, and then we compare the computed version against
+ * the ondisk version. We use the 'xfile' functionality to store this
+ * (potentially large) amount of data in pageable memory.
+ */
+
+/* Set us up to check the rtsummary file. */
+int
+xchk_setup_rtsummary(
+ struct xfs_scrub *sc)
+{
+ struct xfs_mount *mp = sc->mp;
+ char *descr;
+ int error;
+
+ /*
+ * Create an xfile to construct a new rtsummary file. The xfile allows
+ * us to avoid pinning kernel memory for this purpose.
+ */
+ descr = xchk_xfile_descr(sc, "realtime summary file");
+ error = xfile_create(descr, mp->m_rsumsize, &sc->xfile);
+ kfree(descr);
+ if (error)
+ return error;
+
+ error = xchk_trans_alloc(sc, 0);
+ if (error)
+ return error;
+
+ /* Allocate a memory buffer for the summary comparison. */
+ sc->buf = kvmalloc(mp->m_sb.sb_blocksize, XCHK_GFP_FLAGS);
+ if (!sc->buf)
+ return -ENOMEM;
+
+ error = xchk_install_live_inode(sc, mp->m_rsumip);
+ if (error)
+ return error;
+
+ /*
+ * Locking order requires us to take the rtbitmap first. We must be
+ * careful to unlock it ourselves when we are done with the rtbitmap
+ * file since the scrub infrastructure won't do that for us. Only
+ * then we can lock the rtsummary inode.
+ */
+ xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+ xchk_ilock(sc, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
+ return 0;
+}
+
+/* Helper functions to record suminfo words in an xfile. */
+
+typedef unsigned int xchk_rtsumoff_t;
+
+static inline int
+xfsum_load(
+ struct xfs_scrub *sc,
+ xchk_rtsumoff_t sumoff,
+ xfs_suminfo_t *info)
+{
+ return xfile_obj_load(sc->xfile, info, sizeof(xfs_suminfo_t),
+ sumoff << XFS_WORDLOG);
+}
+
+static inline int
+xfsum_store(
+ struct xfs_scrub *sc,
+ xchk_rtsumoff_t sumoff,
+ const xfs_suminfo_t info)
+{
+ return xfile_obj_store(sc->xfile, &info, sizeof(xfs_suminfo_t),
+ sumoff << XFS_WORDLOG);
+}
+
+static inline int
+xfsum_copyout(
+ struct xfs_scrub *sc,
+ xchk_rtsumoff_t sumoff,
+ xfs_suminfo_t *info,
+ unsigned int nr_words)
+{
+ return xfile_obj_load(sc->xfile, info, nr_words << XFS_WORDLOG,
+ sumoff << XFS_WORDLOG);
+}
+
+/* Update the summary file to reflect the free extent that we've accumulated. */
+STATIC int
+xchk_rtsum_record_free(
+ struct xfs_mount *mp,
+ struct xfs_trans *tp,
+ const struct xfs_rtalloc_rec *rec,
+ void *priv)
+{
+ struct xfs_scrub *sc = priv;
+ xfs_fileoff_t rbmoff;
+ xfs_rtblock_t rtbno;
+ xfs_filblks_t rtlen;
+ xchk_rtsumoff_t offs;
+ unsigned int lenlog;
+ xfs_suminfo_t v = 0;
+ int error = 0;
+
+ if (xchk_should_terminate(sc, &error))
+ return error;
+
+ /* Compute the relevant location in the rtsum file. */
+ rbmoff = XFS_BITTOBLOCK(mp, rec->ar_startext);
+ lenlog = XFS_RTBLOCKLOG(rec->ar_extcount);
+ offs = XFS_SUMOFFS(mp, lenlog, rbmoff);
+
+ rtbno = rec->ar_startext * mp->m_sb.sb_rextsize;
+ rtlen = rec->ar_extcount * mp->m_sb.sb_rextsize;
+
+ if (!xfs_verify_rtext(mp, rtbno, rtlen)) {
+ xchk_ino_xref_set_corrupt(sc, mp->m_rbmip->i_ino);
+ return -EFSCORRUPTED;
+ }
+
+ /* Bump the summary count. */
+ error = xfsum_load(sc, offs, &v);
+ if (error)
+ return error;
+
+ v++;
+ trace_xchk_rtsum_record_free(mp, rec->ar_startext, rec->ar_extcount,
+ lenlog, offs, v);
+
+ return xfsum_store(sc, offs, v);
+}
+
+/* Compute the realtime summary from the realtime bitmap. */
+STATIC int
+xchk_rtsum_compute(
+ struct xfs_scrub *sc)
+{
+ struct xfs_mount *mp = sc->mp;
+ unsigned long long rtbmp_bytes;
+
+ /* If the bitmap size doesn't match the computed size, bail. */
+ rtbmp_bytes = howmany_64(mp->m_sb.sb_rextents, NBBY);
+ if (roundup_64(rtbmp_bytes, mp->m_sb.sb_blocksize) !=
+ mp->m_rbmip->i_disk_size)
+ return -EFSCORRUPTED;
+
+ return xfs_rtalloc_query_all(sc->mp, sc->tp, xchk_rtsum_record_free,
+ sc);
+}
+
+/* Compare the rtsummary file against the one we computed. */
+STATIC int
+xchk_rtsum_compare(
+ struct xfs_scrub *sc)
+{
+ struct xfs_mount *mp = sc->mp;
+ struct xfs_buf *bp;
+ struct xfs_bmbt_irec map;
+ xfs_fileoff_t off;
+ xchk_rtsumoff_t sumoff = 0;
+ int nmap;
+
+ for (off = 0; off < XFS_B_TO_FSB(mp, mp->m_rsumsize); off++) {
+ int error = 0;
+
+ if (xchk_should_terminate(sc, &error))
+ return error;
+ if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ return 0;
+
+ /* Make sure we have a written extent. */
+ nmap = 1;
+ error = xfs_bmapi_read(mp->m_rsumip, off, 1, &map, &nmap,
+ XFS_DATA_FORK);
+ if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
+ return error;
+
+ if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) {
+ xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
+ return 0;
+ }
+
+ /* Read a block's worth of ondisk rtsummary file. */
+ error = xfs_rtbuf_get(mp, sc->tp, off, 1, &bp);
+ if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
+ return error;
+
+ /* Read a block's worth of computed rtsummary file. */
+ error = xfsum_copyout(sc, sumoff, sc->buf, mp->m_blockwsize);
+ if (error) {
+ xfs_trans_brelse(sc->tp, bp);
+ return error;
+ }
+
+ if (memcmp(bp->b_addr, sc->buf,
+ mp->m_blockwsize << XFS_WORDLOG) != 0)
+ xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
+
+ xfs_trans_brelse(sc->tp, bp);
+ sumoff += mp->m_blockwsize;
+ }
+
+ return 0;
+}
+
+/* Scrub the realtime summary. */
+int
+xchk_rtsummary(
+ struct xfs_scrub *sc)
+{
+ struct xfs_mount *mp = sc->mp;
+ int error = 0;
+
+ /* Invoke the fork scrubber. */
+ error = xchk_metadata_inode_forks(sc);
+ if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+ goto out_rbm;
+
+ /* Construct the new summary file from the rtbitmap. */
+ error = xchk_rtsum_compute(sc);
+ if (error == -EFSCORRUPTED) {
+ /*
+ * EFSCORRUPTED means the rtbitmap is corrupt, which is an xref
+ * error since we're checking the summary file.
+ */
+ xchk_ino_xref_set_corrupt(sc, mp->m_rbmip->i_ino);
+ error = 0;
+ goto out_rbm;
+ }
+ if (error)
+ goto out_rbm;
+
+ /* Does the computed summary file match the actual rtsummary file? */
+ error = xchk_rtsum_compare(sc);
+
+out_rbm:
+ /* Unlock the rtbitmap since we're done with it. */
+ xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
+ return error;
+}