--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2021-2024 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_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_iwalk.h"
+#include "xfs_ialloc.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_ag.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/repair.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"
+#include "scrub/iscan.h"
+#include "scrub/nlinks.h"
+#include "scrub/trace.h"
+#include "scrub/readdir.h"
+
+/*
+ * Live Inode Link Count Checking
+ * ==============================
+ *
+ * Inode link counts are "summary" metadata, in the sense that they are
+ * computed as the number of directory entries referencing each file on the
+ * filesystem. Therefore, we compute the correct link counts by creating a
+ * shadow link count structure and walking every inode.
+ */
+
+/* Set us up to scrub inode link counts. */
+int
+xchk_setup_nlinks(
+ struct xfs_scrub *sc)
+{
+ /* Not ready for general consumption yet. */
+ return -EOPNOTSUPP;
+
+ sc->buf = kzalloc(sizeof(struct xchk_nlink_ctrs), XCHK_GFP_FLAGS);
+ if (!sc->buf)
+ return -ENOMEM;
+
+ return xchk_setup_fs(sc);
+}
+
+/*
+ * Part 1: Collecting file link counts. For each file, we create a shadow link
+ * counting structure, then walk the entire directory tree, incrementing parent
+ * and child link counts for each directory entry seen.
+ *
+ * To avoid false corruption reports in part 2, any failure in this part must
+ * set the INCOMPLETE flag even when a negative errno is returned. This care
+ * must be taken with certain errno values (i.e. EFSBADCRC, EFSCORRUPTED,
+ * ECANCELED) that are absorbed into a scrub state flag update by
+ * xchk_*_process_error.
+ */
+
+/*
+ * Add a delta to an nlink counter, clamping the value to U32_MAX. Because
+ * XFS_MAXLINK < U32_MAX, the checking code will produce the correct results
+ * even if we lose some precision.
+ */
+static inline void
+careful_add(
+ xfs_nlink_t *nlinkp,
+ int delta)
+{
+ uint64_t new_value = (uint64_t)(*nlinkp) + delta;
+
+ BUILD_BUG_ON(XFS_MAXLINK > U32_MAX);
+ *nlinkp = min_t(uint64_t, new_value, U32_MAX);
+}
+
+/* Update incore link count information. Caller must hold the nlinks lock. */
+STATIC int
+xchk_nlinks_update_incore(
+ struct xchk_nlink_ctrs *xnc,
+ xfs_ino_t ino,
+ int parents_delta,
+ int backrefs_delta,
+ int children_delta)
+{
+ struct xchk_nlink nl;
+ int error;
+
+ if (!xnc->nlinks)
+ return 0;
+
+ error = xfarray_load_sparse(xnc->nlinks, ino, &nl);
+ if (error)
+ return error;
+
+ trace_xchk_nlinks_update_incore(xnc->sc->mp, ino, &nl, parents_delta,
+ backrefs_delta, children_delta);
+
+ careful_add(&nl.parents, parents_delta);
+ careful_add(&nl.backrefs, backrefs_delta);
+ careful_add(&nl.children, children_delta);
+
+ nl.flags |= XCHK_NLINK_WRITTEN;
+ error = xfarray_store(xnc->nlinks, ino, &nl);
+ if (error == -EFBIG) {
+ /*
+ * EFBIG means we tried to store data at too high a byte offset
+ * in the sparse array. IOWs, we cannot complete the check and
+ * must notify userspace that the check was incomplete.
+ */
+ error = -ECANCELED;
+ }
+ return error;
+}
+
+/* Bump the observed link count for the inode referenced by this entry. */
+STATIC int
+xchk_nlinks_collect_dirent(
+ struct xfs_scrub *sc,
+ struct xfs_inode *dp,
+ xfs_dir2_dataptr_t dapos,
+ const struct xfs_name *name,
+ xfs_ino_t ino,
+ void *priv)
+{
+ struct xchk_nlink_ctrs *xnc = priv;
+ bool dot = false, dotdot = false;
+ int error;
+
+ /* Does this name make sense? */
+ if (name->len == 0 || !xfs_dir2_namecheck(name->name, name->len)) {
+ error = -ECANCELED;
+ goto out_abort;
+ }
+
+ if (name->len == 1 && name->name[0] == '.')
+ dot = true;
+ else if (name->len == 2 && name->name[0] == '.' &&
+ name->name[1] == '.')
+ dotdot = true;
+
+ /* Don't accept a '.' entry that points somewhere else. */
+ if (dot && ino != dp->i_ino) {
+ error = -ECANCELED;
+ goto out_abort;
+ }
+
+ /* Don't accept an invalid inode number. */
+ if (!xfs_verify_dir_ino(sc->mp, ino)) {
+ error = -ECANCELED;
+ goto out_abort;
+ }
+
+ /* Update the shadow link counts if we haven't already failed. */
+
+ if (xchk_iscan_aborted(&xnc->collect_iscan)) {
+ error = -ECANCELED;
+ goto out_incomplete;
+ }
+
+ trace_xchk_nlinks_collect_dirent(sc->mp, dp, ino, name);
+
+ mutex_lock(&xnc->lock);
+
+ /*
+ * If this is a dotdot entry, it is a back link from dp to ino. How
+ * we handle this depends on whether or not dp is the root directory.
+ *
+ * The root directory is its own parent, so we pretend the dotdot entry
+ * establishes the "parent" of the root directory. Increment the
+ * number of parents of the root directory.
+ *
+ * Otherwise, increment the number of backrefs pointing back to ino.
+ */
+ if (dotdot) {
+ if (dp == sc->mp->m_rootip)
+ error = xchk_nlinks_update_incore(xnc, ino, 1, 0, 0);
+ else
+ error = xchk_nlinks_update_incore(xnc, ino, 0, 1, 0);
+ if (error)
+ goto out_unlock;
+ }
+
+ /*
+ * If this dirent is a forward link from dp to ino, increment the
+ * number of parents linking into ino.
+ */
+ if (!dot && !dotdot) {
+ error = xchk_nlinks_update_incore(xnc, ino, 1, 0, 0);
+ if (error)
+ goto out_unlock;
+ }
+
+ /*
+ * If this dirent is a forward link to a subdirectory, increment the
+ * number of child links of dp.
+ */
+ if (!dot && !dotdot && name->type == XFS_DIR3_FT_DIR) {
+ error = xchk_nlinks_update_incore(xnc, dp->i_ino, 0, 0, 1);
+ if (error)
+ goto out_unlock;
+ }
+
+ mutex_unlock(&xnc->lock);
+ return 0;
+
+out_unlock:
+ mutex_unlock(&xnc->lock);
+out_abort:
+ xchk_iscan_abort(&xnc->collect_iscan);
+out_incomplete:
+ xchk_set_incomplete(sc);
+ return error;
+}
+
+/* Walk a directory to bump the observed link counts of the children. */
+STATIC int
+xchk_nlinks_collect_dir(
+ struct xchk_nlink_ctrs *xnc,
+ struct xfs_inode *dp)
+{
+ struct xfs_scrub *sc = xnc->sc;
+ unsigned int lock_mode;
+ int error = 0;
+
+ /* Prevent anyone from changing this directory while we walk it. */
+ xfs_ilock(dp, XFS_IOLOCK_SHARED);
+ lock_mode = xfs_ilock_data_map_shared(dp);
+
+ /*
+ * The dotdot entry of an unlinked directory still points to the last
+ * parent, but the parent no longer links to this directory. Skip the
+ * directory to avoid overcounting.
+ */
+ if (VFS_I(dp)->i_nlink == 0)
+ goto out_unlock;
+
+ /*
+ * We cannot count file links if the directory looks as though it has
+ * been zapped by the inode record repair code.
+ */
+ if (xchk_dir_looks_zapped(dp)) {
+ error = -EBUSY;
+ goto out_abort;
+ }
+
+ error = xchk_dir_walk(sc, dp, xchk_nlinks_collect_dirent, xnc);
+ if (error == -ECANCELED) {
+ error = 0;
+ goto out_unlock;
+ }
+ if (error)
+ goto out_abort;
+
+ xchk_iscan_mark_visited(&xnc->collect_iscan, dp);
+ goto out_unlock;
+
+out_abort:
+ xchk_set_incomplete(sc);
+ xchk_iscan_abort(&xnc->collect_iscan);
+out_unlock:
+ xfs_iunlock(dp, lock_mode);
+ xfs_iunlock(dp, XFS_IOLOCK_SHARED);
+ return error;
+}
+
+/* If this looks like a valid pointer, count it. */
+static inline int
+xchk_nlinks_collect_metafile(
+ struct xchk_nlink_ctrs *xnc,
+ xfs_ino_t ino)
+{
+ if (!xfs_verify_ino(xnc->sc->mp, ino))
+ return 0;
+
+ trace_xchk_nlinks_collect_metafile(xnc->sc->mp, ino);
+ return xchk_nlinks_update_incore(xnc, ino, 1, 0, 0);
+}
+
+/* Bump the link counts of metadata files rooted in the superblock. */
+STATIC int
+xchk_nlinks_collect_metafiles(
+ struct xchk_nlink_ctrs *xnc)
+{
+ struct xfs_mount *mp = xnc->sc->mp;
+ int error = -ECANCELED;
+
+
+ if (xchk_iscan_aborted(&xnc->collect_iscan))
+ goto out_incomplete;
+
+ mutex_lock(&xnc->lock);
+ error = xchk_nlinks_collect_metafile(xnc, mp->m_sb.sb_rbmino);
+ if (error)
+ goto out_abort;
+
+ error = xchk_nlinks_collect_metafile(xnc, mp->m_sb.sb_rsumino);
+ if (error)
+ goto out_abort;
+
+ error = xchk_nlinks_collect_metafile(xnc, mp->m_sb.sb_uquotino);
+ if (error)
+ goto out_abort;
+
+ error = xchk_nlinks_collect_metafile(xnc, mp->m_sb.sb_gquotino);
+ if (error)
+ goto out_abort;
+
+ error = xchk_nlinks_collect_metafile(xnc, mp->m_sb.sb_pquotino);
+ if (error)
+ goto out_abort;
+ mutex_unlock(&xnc->lock);
+
+ return 0;
+
+out_abort:
+ mutex_unlock(&xnc->lock);
+ xchk_iscan_abort(&xnc->collect_iscan);
+out_incomplete:
+ xchk_set_incomplete(xnc->sc);
+ return error;
+}
+
+/* Advance the collection scan cursor for this non-directory file. */
+static inline int
+xchk_nlinks_collect_file(
+ struct xchk_nlink_ctrs *xnc,
+ struct xfs_inode *ip)
+{
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ xchk_iscan_mark_visited(&xnc->collect_iscan, ip);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+ return 0;
+}
+
+/* Walk all directories and count inode links. */
+STATIC int
+xchk_nlinks_collect(
+ struct xchk_nlink_ctrs *xnc)
+{
+ struct xfs_scrub *sc = xnc->sc;
+ struct xfs_inode *ip;
+ int error;
+
+ /* Count the rt and quota files that are rooted in the superblock. */
+ error = xchk_nlinks_collect_metafiles(xnc);
+ if (error)
+ return error;
+
+ /*
+ * Set up for a potentially lengthy filesystem scan by reducing our
+ * transaction resource usage for the duration. Specifically:
+ *
+ * Cancel the transaction to release the log grant space while we scan
+ * the filesystem.
+ *
+ * Create a new empty transaction to eliminate the possibility of the
+ * inode scan deadlocking on cyclical metadata.
+ *
+ * We pass the empty transaction to the file scanning function to avoid
+ * repeatedly cycling empty transactions. This can be done even though
+ * we take the IOLOCK to quiesce the file because empty transactions
+ * do not take sb_internal.
+ */
+ xchk_trans_cancel(sc);
+ error = xchk_trans_alloc_empty(sc);
+ if (error)
+ return error;
+
+ while ((error = xchk_iscan_iter(&xnc->collect_iscan, &ip)) == 1) {
+ if (S_ISDIR(VFS_I(ip)->i_mode))
+ error = xchk_nlinks_collect_dir(xnc, ip);
+ else
+ error = xchk_nlinks_collect_file(xnc, ip);
+ xchk_irele(sc, ip);
+ if (error)
+ break;
+
+ if (xchk_should_terminate(sc, &error))
+ break;
+ }
+ xchk_iscan_iter_finish(&xnc->collect_iscan);
+ if (error) {
+ xchk_set_incomplete(sc);
+ /*
+ * If we couldn't grab an inode that was busy with a state
+ * change, change the error code so that we exit to userspace
+ * as quickly as possible.
+ */
+ if (error == -EBUSY)
+ return -ECANCELED;
+ return error;
+ }
+
+ /*
+ * Switch out for a real transaction in preparation for building a new
+ * tree.
+ */
+ xchk_trans_cancel(sc);
+ return xchk_setup_fs(sc);
+}
+
+/*
+ * Part 2: Comparing file link counters. Walk each inode and compare the link
+ * counts against our shadow information; and then walk each shadow link count
+ * structure (that wasn't covered in the first part), comparing it against the
+ * file.
+ */
+
+/* Read the observed link count for comparison with the actual inode. */
+STATIC int
+xchk_nlinks_comparison_read(
+ struct xchk_nlink_ctrs *xnc,
+ xfs_ino_t ino,
+ struct xchk_nlink *obs)
+{
+ struct xchk_nlink nl;
+ int error;
+
+ error = xfarray_load_sparse(xnc->nlinks, ino, &nl);
+ if (error)
+ return error;
+
+ nl.flags |= (XCHK_NLINK_COMPARE_SCANNED | XCHK_NLINK_WRITTEN);
+
+ error = xfarray_store(xnc->nlinks, ino, &nl);
+ if (error == -EFBIG) {
+ /*
+ * EFBIG means we tried to store data at too high a byte offset
+ * in the sparse array. IOWs, we cannot complete the check and
+ * must notify userspace that the check was incomplete. This
+ * shouldn't really happen outside of the collection phase.
+ */
+ xchk_set_incomplete(xnc->sc);
+ return -ECANCELED;
+ }
+ if (error)
+ return error;
+
+ /* Copy the counters, but do not expose the internal state. */
+ obs->parents = nl.parents;
+ obs->backrefs = nl.backrefs;
+ obs->children = nl.children;
+ obs->flags = 0;
+ return 0;
+}
+
+/* Check our link count against an inode. */
+STATIC int
+xchk_nlinks_compare_inode(
+ struct xchk_nlink_ctrs *xnc,
+ struct xfs_inode *ip)
+{
+ struct xchk_nlink obs;
+ struct xfs_scrub *sc = xnc->sc;
+ uint64_t total_links;
+ unsigned int actual_nlink;
+ int error;
+
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ mutex_lock(&xnc->lock);
+
+ if (xchk_iscan_aborted(&xnc->collect_iscan)) {
+ xchk_set_incomplete(xnc->sc);
+ error = -ECANCELED;
+ goto out_scanlock;
+ }
+
+ error = xchk_nlinks_comparison_read(xnc, ip->i_ino, &obs);
+ if (error)
+ goto out_scanlock;
+
+ /*
+ * If we don't have ftype to get an accurate count of the subdirectory
+ * entries in this directory, take advantage of the fact that on a
+ * consistent ftype=0 filesystem, the number of subdirectory
+ * backreferences (dotdot entries) pointing towards this directory
+ * should be equal to the number of subdirectory entries in the
+ * directory.
+ */
+ if (!xfs_has_ftype(sc->mp) && S_ISDIR(VFS_I(ip)->i_mode))
+ obs.children = obs.backrefs;
+
+ total_links = xchk_nlink_total(ip, &obs);
+ actual_nlink = VFS_I(ip)->i_nlink;
+
+ trace_xchk_nlinks_compare_inode(sc->mp, ip, &obs);
+
+ /*
+ * If we found so many parents that we'd overflow i_nlink, we must flag
+ * this as a corruption. The VFS won't let users increase the link
+ * count, but it will let them decrease it.
+ */
+ if (total_links > XFS_MAXLINK) {
+ xchk_ino_set_corrupt(sc, ip->i_ino);
+ goto out_corrupt;
+ }
+
+ /* Link counts should match. */
+ if (total_links != actual_nlink) {
+ xchk_ino_set_corrupt(sc, ip->i_ino);
+ goto out_corrupt;
+ }
+
+ if (S_ISDIR(VFS_I(ip)->i_mode) && actual_nlink > 0) {
+ /*
+ * The collection phase ignores directories with zero link
+ * count, so we ignore them here too.
+ *
+ * The number of subdirectory backreferences (dotdot entries)
+ * pointing towards this directory should be equal to the
+ * number of subdirectory entries in the directory.
+ */
+ if (obs.children != obs.backrefs)
+ xchk_ino_xref_set_corrupt(sc, ip->i_ino);
+ } else {
+ /*
+ * Non-directories and unlinked directories should not have
+ * back references.
+ */
+ if (obs.backrefs != 0) {
+ xchk_ino_set_corrupt(sc, ip->i_ino);
+ goto out_corrupt;
+ }
+
+ /*
+ * Non-directories and unlinked directories should not have
+ * children.
+ */
+ if (obs.children != 0) {
+ xchk_ino_set_corrupt(sc, ip->i_ino);
+ goto out_corrupt;
+ }
+ }
+
+ if (ip == sc->mp->m_rootip) {
+ /*
+ * For the root of a directory tree, both the '.' and '..'
+ * entries should point to the root directory. The dotdot
+ * entry is counted as a parent of the root /and/ a backref of
+ * the root directory.
+ */
+ if (obs.parents != 1) {
+ xchk_ino_set_corrupt(sc, ip->i_ino);
+ goto out_corrupt;
+ }
+ } else if (actual_nlink > 0) {
+ /*
+ * Linked files that are not the root directory should have at
+ * least one parent.
+ */
+ if (obs.parents == 0) {
+ xchk_ino_set_corrupt(sc, ip->i_ino);
+ goto out_corrupt;
+ }
+ }
+
+out_corrupt:
+ if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ error = -ECANCELED;
+out_scanlock:
+ mutex_unlock(&xnc->lock);
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ return error;
+}
+
+/*
+ * Check our link count against an inode that wasn't checked previously. This
+ * is intended to catch directories with dangling links, though we could be
+ * racing with inode allocation in other threads.
+ */
+STATIC int
+xchk_nlinks_compare_inum(
+ struct xchk_nlink_ctrs *xnc,
+ xfs_ino_t ino)
+{
+ struct xchk_nlink obs;
+ struct xfs_mount *mp = xnc->sc->mp;
+ struct xfs_trans *tp = xnc->sc->tp;
+ struct xfs_buf *agi_bp;
+ struct xfs_inode *ip;
+ int error;
+
+ /*
+ * The first iget failed, so try again with the variant that returns
+ * either an incore inode or the AGI buffer. If the function returns
+ * EINVAL/ENOENT, it should have passed us the AGI buffer so that we
+ * can guarantee that the inode won't be allocated while we check for
+ * a zero link count in the observed link count data.
+ */
+ error = xchk_iget_agi(xnc->sc, ino, &agi_bp, &ip);
+ if (!error) {
+ /* Actually got an inode, so use the inode compare. */
+ error = xchk_nlinks_compare_inode(xnc, ip);
+ xchk_irele(xnc->sc, ip);
+ return error;
+ }
+ if (error == -ENOENT || error == -EINVAL) {
+ /* No inode was found. Check for zero link count below. */
+ error = 0;
+ }
+ if (error)
+ goto out_agi;
+
+ /* Ensure that we have protected against inode allocation/freeing. */
+ if (agi_bp == NULL) {
+ ASSERT(agi_bp != NULL);
+ xchk_set_incomplete(xnc->sc);
+ return -ECANCELED;
+ }
+
+ if (xchk_iscan_aborted(&xnc->collect_iscan)) {
+ xchk_set_incomplete(xnc->sc);
+ error = -ECANCELED;
+ goto out_agi;
+ }
+
+ mutex_lock(&xnc->lock);
+ error = xchk_nlinks_comparison_read(xnc, ino, &obs);
+ if (error)
+ goto out_scanlock;
+
+ trace_xchk_nlinks_check_zero(mp, ino, &obs);
+
+ /*
+ * If we can't grab the inode, the link count had better be zero. We
+ * still hold the AGI to prevent inode allocation/freeing.
+ */
+ if (xchk_nlink_total(NULL, &obs) != 0) {
+ xchk_ino_set_corrupt(xnc->sc, ino);
+ error = -ECANCELED;
+ }
+
+out_scanlock:
+ mutex_unlock(&xnc->lock);
+out_agi:
+ if (agi_bp)
+ xfs_trans_brelse(tp, agi_bp);
+ return error;
+}
+
+/*
+ * Try to visit every inode in the filesystem to compare the link count. Move
+ * on if we can't grab an inode, since we'll revisit unchecked nlink records in
+ * the second part.
+ */
+static int
+xchk_nlinks_compare_iter(
+ struct xchk_nlink_ctrs *xnc,
+ struct xfs_inode **ipp)
+{
+ int error;
+
+ do {
+ error = xchk_iscan_iter(&xnc->compare_iscan, ipp);
+ } while (error == -EBUSY);
+
+ return error;
+}
+
+/* Compare the link counts we observed against the live information. */
+STATIC int
+xchk_nlinks_compare(
+ struct xchk_nlink_ctrs *xnc)
+{
+ struct xchk_nlink nl;
+ struct xfs_scrub *sc = xnc->sc;
+ struct xfs_inode *ip;
+ xfarray_idx_t cur = XFARRAY_CURSOR_INIT;
+ int error;
+
+ if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ return 0;
+
+ /*
+ * Create a new empty transaction so that we can advance the iscan
+ * cursor without deadlocking if the inobt has a cycle and push on the
+ * inactivation workqueue.
+ */
+ xchk_trans_cancel(sc);
+ error = xchk_trans_alloc_empty(sc);
+ if (error)
+ return error;
+
+ /*
+ * Use the inobt to walk all allocated inodes to compare the link
+ * counts. Inodes skipped by _compare_iter will be tried again in the
+ * next phase of the scan.
+ */
+ xchk_iscan_start(sc, 0, 0, &xnc->compare_iscan);
+ while ((error = xchk_nlinks_compare_iter(xnc, &ip)) == 1) {
+ error = xchk_nlinks_compare_inode(xnc, ip);
+ xchk_iscan_mark_visited(&xnc->compare_iscan, ip);
+ xchk_irele(sc, ip);
+ if (error)
+ break;
+
+ if (xchk_should_terminate(sc, &error))
+ break;
+ }
+ xchk_iscan_iter_finish(&xnc->compare_iscan);
+ xchk_iscan_teardown(&xnc->compare_iscan);
+ if (error)
+ return error;
+
+ if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ return 0;
+
+ /*
+ * Walk all the non-null nlink observations that weren't checked in the
+ * previous step.
+ */
+ mutex_lock(&xnc->lock);
+ while ((error = xfarray_iter(xnc->nlinks, &cur, &nl)) == 1) {
+ xfs_ino_t ino = cur - 1;
+
+ if (nl.flags & XCHK_NLINK_COMPARE_SCANNED)
+ continue;
+
+ mutex_unlock(&xnc->lock);
+
+ error = xchk_nlinks_compare_inum(xnc, ino);
+ if (error)
+ return error;
+
+ if (xchk_should_terminate(xnc->sc, &error))
+ return error;
+
+ mutex_lock(&xnc->lock);
+ }
+ mutex_unlock(&xnc->lock);
+
+ return error;
+}
+
+/* Tear down everything associated with a nlinks check. */
+static void
+xchk_nlinks_teardown_scan(
+ void *priv)
+{
+ struct xchk_nlink_ctrs *xnc = priv;
+
+ xfarray_destroy(xnc->nlinks);
+ xnc->nlinks = NULL;
+
+ xchk_iscan_teardown(&xnc->collect_iscan);
+ mutex_destroy(&xnc->lock);
+ xnc->sc = NULL;
+}
+
+/*
+ * Scan all inodes in the entire filesystem to generate link count data. If
+ * the scan is successful, the counts will be left alive for a repair. If any
+ * error occurs, we'll tear everything down.
+ */
+STATIC int
+xchk_nlinks_setup_scan(
+ struct xfs_scrub *sc,
+ struct xchk_nlink_ctrs *xnc)
+{
+ struct xfs_mount *mp = sc->mp;
+ char *descr;
+ unsigned long long max_inos;
+ xfs_agnumber_t last_agno = mp->m_sb.sb_agcount - 1;
+ xfs_agino_t first_agino, last_agino;
+ int error;
+
+ ASSERT(xnc->sc == NULL);
+ xnc->sc = sc;
+
+ mutex_init(&xnc->lock);
+
+ /* Retry iget every tenth of a second for up to 30 seconds. */
+ xchk_iscan_start(sc, 30000, 100, &xnc->collect_iscan);
+
+ /*
+ * Set up enough space to store an nlink record for the highest
+ * possible inode number in this system.
+ */
+ xfs_agino_range(mp, last_agno, &first_agino, &last_agino);
+ max_inos = XFS_AGINO_TO_INO(mp, last_agno, last_agino) + 1;
+ descr = xchk_xfile_descr(sc, "file link counts");
+ error = xfarray_create(descr, min(XFS_MAXINUMBER + 1, max_inos),
+ sizeof(struct xchk_nlink), &xnc->nlinks);
+ kfree(descr);
+ if (error)
+ goto out_teardown;
+
+ /* Use deferred cleanup to pass the inode link count data to repair. */
+ sc->buf_cleanup = xchk_nlinks_teardown_scan;
+ return 0;
+
+out_teardown:
+ xchk_nlinks_teardown_scan(xnc);
+ return error;
+}
+
+/* Scrub the link count of all inodes on the filesystem. */
+int
+xchk_nlinks(
+ struct xfs_scrub *sc)
+{
+ struct xchk_nlink_ctrs *xnc = sc->buf;
+ int error = 0;
+
+ /* Set ourselves up to check link counts on the live filesystem. */
+ error = xchk_nlinks_setup_scan(sc, xnc);
+ if (error)
+ return error;
+
+ /* Walk all inodes, picking up link count information. */
+ error = xchk_nlinks_collect(xnc);
+ if (!xchk_xref_process_error(sc, 0, 0, &error))
+ return error;
+
+ /* Fail fast if we're not playing with a full dataset. */
+ if (xchk_iscan_aborted(&xnc->collect_iscan))
+ xchk_set_incomplete(sc);
+ if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_INCOMPLETE)
+ return 0;
+
+ /* Compare link counts. */
+ error = xchk_nlinks_compare(xnc);
+ if (!xchk_xref_process_error(sc, 0, 0, &error))
+ return error;
+
+ /* Check one last time for an incomplete dataset. */
+ if (xchk_iscan_aborted(&xnc->collect_iscan))
+ xchk_set_incomplete(sc);
+
+ return 0;
+}
struct xfarray_sortinfo;
struct xchk_dqiter;
struct xchk_iscan;
+struct xchk_nlink;
/*
* ftrace's __print_symbolic requires that all enum values be wrapped in the
TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_PQUOTA);
TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_FSCOUNTERS);
TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_QUOTACHECK);
+TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_NLINKS);
#define XFS_SCRUB_TYPE_STRINGS \
{ XFS_SCRUB_TYPE_PROBE, "probe" }, \
{ XFS_SCRUB_TYPE_GQUOTA, "grpquota" }, \
{ XFS_SCRUB_TYPE_PQUOTA, "prjquota" }, \
{ XFS_SCRUB_TYPE_FSCOUNTERS, "fscounters" }, \
- { XFS_SCRUB_TYPE_QUOTACHECK, "quotacheck" }
+ { XFS_SCRUB_TYPE_QUOTACHECK, "quotacheck" }, \
+ { XFS_SCRUB_TYPE_NLINKS, "nlinks" }
#define XFS_SCRUB_FLAG_STRINGS \
{ XFS_SCRUB_IFLAG_REPAIR, "repair" }, \
__entry->retry_delay)
);
+TRACE_EVENT(xchk_nlinks_collect_dirent,
+ TP_PROTO(struct xfs_mount *mp, struct xfs_inode *dp,
+ xfs_ino_t ino, const struct xfs_name *name),
+ TP_ARGS(mp, dp, ino, name),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, dir)
+ __field(xfs_ino_t, ino)
+ __field(unsigned int, namelen)
+ __dynamic_array(char, name, name->len)
+ ),
+ TP_fast_assign(
+ __entry->dev = mp->m_super->s_dev;
+ __entry->dir = dp->i_ino;
+ __entry->ino = ino;
+ __entry->namelen = name->len;
+ memcpy(__get_str(name), name->name, name->len);
+ ),
+ TP_printk("dev %d:%d dir 0x%llx -> ino 0x%llx name '%.*s'",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->dir,
+ __entry->ino,
+ __entry->namelen,
+ __get_str(name))
+);
+
+TRACE_EVENT(xchk_nlinks_collect_metafile,
+ TP_PROTO(struct xfs_mount *mp, xfs_ino_t ino),
+ TP_ARGS(mp, ino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, ino)
+ ),
+ TP_fast_assign(
+ __entry->dev = mp->m_super->s_dev;
+ __entry->ino = ino;
+ ),
+ TP_printk("dev %d:%d ino 0x%llx",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino)
+);
+
+TRACE_EVENT(xchk_nlinks_check_zero,
+ TP_PROTO(struct xfs_mount *mp, xfs_ino_t ino,
+ const struct xchk_nlink *live),
+ TP_ARGS(mp, ino, live),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, ino)
+ __field(xfs_nlink_t, parents)
+ __field(xfs_nlink_t, backrefs)
+ __field(xfs_nlink_t, children)
+ ),
+ TP_fast_assign(
+ __entry->dev = mp->m_super->s_dev;
+ __entry->ino = ino;
+ __entry->parents = live->parents;
+ __entry->backrefs = live->backrefs;
+ __entry->children = live->children;
+ ),
+ TP_printk("dev %d:%d ino 0x%llx parents %u backrefs %u children %u",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __entry->parents,
+ __entry->backrefs,
+ __entry->children)
+);
+
+TRACE_EVENT(xchk_nlinks_update_incore,
+ TP_PROTO(struct xfs_mount *mp, xfs_ino_t ino,
+ const struct xchk_nlink *live, int parents_delta,
+ int backrefs_delta, int children_delta),
+ TP_ARGS(mp, ino, live, parents_delta, backrefs_delta, children_delta),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, ino)
+ __field(xfs_nlink_t, parents)
+ __field(xfs_nlink_t, backrefs)
+ __field(xfs_nlink_t, children)
+ __field(int, parents_delta)
+ __field(int, backrefs_delta)
+ __field(int, children_delta)
+ ),
+ TP_fast_assign(
+ __entry->dev = mp->m_super->s_dev;
+ __entry->ino = ino;
+ __entry->parents = live->parents;
+ __entry->backrefs = live->backrefs;
+ __entry->children = live->children;
+ __entry->parents_delta = parents_delta;
+ __entry->backrefs_delta = backrefs_delta;
+ __entry->children_delta = children_delta;
+ ),
+ TP_printk("dev %d:%d ino 0x%llx parents %d:%u backrefs %d:%u children %d:%u",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __entry->parents_delta,
+ __entry->parents,
+ __entry->backrefs_delta,
+ __entry->backrefs,
+ __entry->children_delta,
+ __entry->children)
+);
+
+DECLARE_EVENT_CLASS(xchk_nlinks_diff_class,
+ TP_PROTO(struct xfs_mount *mp, struct xfs_inode *ip,
+ const struct xchk_nlink *live),
+ TP_ARGS(mp, ip, live),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_ino_t, ino)
+ __field(uint8_t, ftype)
+ __field(xfs_nlink_t, nlink)
+ __field(xfs_nlink_t, parents)
+ __field(xfs_nlink_t, backrefs)
+ __field(xfs_nlink_t, children)
+ ),
+ TP_fast_assign(
+ __entry->dev = mp->m_super->s_dev;
+ __entry->ino = ip->i_ino;
+ __entry->ftype = xfs_mode_to_ftype(VFS_I(ip)->i_mode);
+ __entry->nlink = VFS_I(ip)->i_nlink;
+ __entry->parents = live->parents;
+ __entry->backrefs = live->backrefs;
+ __entry->children = live->children;
+ ),
+ TP_printk("dev %d:%d ino 0x%llx ftype %s nlink %u parents %u backrefs %u children %u",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __print_symbolic(__entry->ftype, XFS_DIR3_FTYPE_STR),
+ __entry->nlink,
+ __entry->parents,
+ __entry->backrefs,
+ __entry->children)
+);
+#define DEFINE_SCRUB_NLINKS_DIFF_EVENT(name) \
+DEFINE_EVENT(xchk_nlinks_diff_class, name, \
+ TP_PROTO(struct xfs_mount *mp, struct xfs_inode *ip, \
+ const struct xchk_nlink *live), \
+ TP_ARGS(mp, ip, live))
+DEFINE_SCRUB_NLINKS_DIFF_EVENT(xchk_nlinks_compare_inode);
+
/* repair tracepoints */
#if IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR)
projects / linux.git / commitdiff