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-rw-r--r--fs/xfs/scrub/dirtree_repair.c821
1 files changed, 821 insertions, 0 deletions
diff --git a/fs/xfs/scrub/dirtree_repair.c b/fs/xfs/scrub/dirtree_repair.c
new file mode 100644
index 0000000000..5c04e70ba9
--- /dev/null
+++ b/fs/xfs/scrub/dirtree_repair.c
@@ -0,0 +1,821 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023-2024 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_trans_space.h"
+#include "xfs_mount.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_attr.h"
+#include "xfs_parent.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/bitmap.h"
+#include "scrub/ino_bitmap.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"
+#include "scrub/xfblob.h"
+#include "scrub/listxattr.h"
+#include "scrub/trace.h"
+#include "scrub/repair.h"
+#include "scrub/orphanage.h"
+#include "scrub/dirtree.h"
+#include "scrub/readdir.h"
+
+/*
+ * Directory Tree Structure Repairs
+ * ================================
+ *
+ * If we decide that the directory being scanned is participating in a
+ * directory loop, the only change we can make is to remove directory entries
+ * pointing down to @sc->ip. If that leaves it with no parents, the directory
+ * should be adopted by the orphanage.
+ */
+
+/* Set up to repair directory loops. */
+int
+xrep_setup_dirtree(
+ struct xfs_scrub *sc)
+{
+ return xrep_orphanage_try_create(sc);
+}
+
+/* Change the outcome of this path. */
+static inline void
+xrep_dirpath_set_outcome(
+ struct xchk_dirtree *dl,
+ struct xchk_dirpath *path,
+ enum xchk_dirpath_outcome outcome)
+{
+ trace_xrep_dirpath_set_outcome(dl->sc, path->path_nr, path->nr_steps,
+ outcome);
+
+ path->outcome = outcome;
+}
+
+/* Delete all paths. */
+STATIC void
+xrep_dirtree_delete_all_paths(
+ struct xchk_dirtree *dl,
+ struct xchk_dirtree_outcomes *oc)
+{
+ struct xchk_dirpath *path;
+
+ xchk_dirtree_for_each_path(dl, path) {
+ switch (path->outcome) {
+ case XCHK_DIRPATH_CORRUPT:
+ case XCHK_DIRPATH_LOOP:
+ oc->suspect--;
+ oc->bad++;
+ xrep_dirpath_set_outcome(dl, path, XCHK_DIRPATH_DELETE);
+ break;
+ case XCHK_DIRPATH_OK:
+ oc->good--;
+ oc->bad++;
+ xrep_dirpath_set_outcome(dl, path, XCHK_DIRPATH_DELETE);
+ break;
+ default:
+ break;
+ }
+ }
+
+ ASSERT(oc->suspect == 0);
+ ASSERT(oc->good == 0);
+}
+
+/* Since this is the surviving path, set the dotdot entry to this value. */
+STATIC void
+xrep_dirpath_retain_parent(
+ struct xchk_dirtree *dl,
+ struct xchk_dirpath *path)
+{
+ struct xchk_dirpath_step step;
+ int error;
+
+ error = xfarray_load(dl->path_steps, path->first_step, &step);
+ if (error)
+ return;
+
+ dl->parent_ino = be64_to_cpu(step.pptr_rec.p_ino);
+}
+
+/* Find the one surviving path so we know how to set dotdot. */
+STATIC void
+xrep_dirtree_find_surviving_path(
+ struct xchk_dirtree *dl,
+ struct xchk_dirtree_outcomes *oc)
+{
+ struct xchk_dirpath *path;
+ bool foundit = false;
+
+ xchk_dirtree_for_each_path(dl, path) {
+ switch (path->outcome) {
+ case XCHK_DIRPATH_CORRUPT:
+ case XCHK_DIRPATH_LOOP:
+ case XCHK_DIRPATH_OK:
+ if (!foundit) {
+ xrep_dirpath_retain_parent(dl, path);
+ foundit = true;
+ continue;
+ }
+ ASSERT(foundit == false);
+ break;
+ default:
+ break;
+ }
+ }
+
+ ASSERT(oc->suspect + oc->good == 1);
+}
+
+/* Delete all paths except for the one good one. */
+STATIC void
+xrep_dirtree_keep_one_good_path(
+ struct xchk_dirtree *dl,
+ struct xchk_dirtree_outcomes *oc)
+{
+ struct xchk_dirpath *path;
+ bool foundit = false;
+
+ xchk_dirtree_for_each_path(dl, path) {
+ switch (path->outcome) {
+ case XCHK_DIRPATH_CORRUPT:
+ case XCHK_DIRPATH_LOOP:
+ oc->suspect--;
+ oc->bad++;
+ xrep_dirpath_set_outcome(dl, path, XCHK_DIRPATH_DELETE);
+ break;
+ case XCHK_DIRPATH_OK:
+ if (!foundit) {
+ xrep_dirpath_retain_parent(dl, path);
+ foundit = true;
+ continue;
+ }
+ oc->good--;
+ oc->bad++;
+ xrep_dirpath_set_outcome(dl, path, XCHK_DIRPATH_DELETE);
+ break;
+ default:
+ break;
+ }
+ }
+
+ ASSERT(oc->suspect == 0);
+ ASSERT(oc->good < 2);
+}
+
+/* Delete all paths except for one suspect one. */
+STATIC void
+xrep_dirtree_keep_one_suspect_path(
+ struct xchk_dirtree *dl,
+ struct xchk_dirtree_outcomes *oc)
+{
+ struct xchk_dirpath *path;
+ bool foundit = false;
+
+ xchk_dirtree_for_each_path(dl, path) {
+ switch (path->outcome) {
+ case XCHK_DIRPATH_CORRUPT:
+ case XCHK_DIRPATH_LOOP:
+ if (!foundit) {
+ xrep_dirpath_retain_parent(dl, path);
+ foundit = true;
+ continue;
+ }
+ oc->suspect--;
+ oc->bad++;
+ xrep_dirpath_set_outcome(dl, path, XCHK_DIRPATH_DELETE);
+ break;
+ case XCHK_DIRPATH_OK:
+ ASSERT(0);
+ break;
+ default:
+ break;
+ }
+ }
+
+ ASSERT(oc->suspect == 1);
+ ASSERT(oc->good == 0);
+}
+
+/*
+ * Figure out what to do with the paths we tried to find. Returns -EDEADLOCK
+ * if the scan results have become stale.
+ */
+STATIC void
+xrep_dirtree_decide_fate(
+ struct xchk_dirtree *dl,
+ struct xchk_dirtree_outcomes *oc)
+{
+ xchk_dirtree_evaluate(dl, oc);
+
+ /* Parentless directories should not have any paths at all. */
+ if (xchk_dirtree_parentless(dl)) {
+ xrep_dirtree_delete_all_paths(dl, oc);
+ return;
+ }
+
+ /* One path is exactly the number of paths we want. */
+ if (oc->good + oc->suspect == 1) {
+ xrep_dirtree_find_surviving_path(dl, oc);
+ return;
+ }
+
+ /* Zero paths means we should reattach the subdir to the orphanage. */
+ if (oc->good + oc->suspect == 0) {
+ if (dl->sc->orphanage)
+ oc->needs_adoption = true;
+ return;
+ }
+
+ /*
+ * Otherwise, this subdirectory has too many parents. If there's at
+ * least one good path, keep it and delete the others.
+ */
+ if (oc->good > 0) {
+ xrep_dirtree_keep_one_good_path(dl, oc);
+ return;
+ }
+
+ /*
+ * There are no good paths and there are too many suspect paths.
+ * Keep the first suspect path and delete the rest.
+ */
+ xrep_dirtree_keep_one_suspect_path(dl, oc);
+}
+
+/*
+ * Load the first step of this path into @step and @dl->xname/pptr
+ * for later repair work.
+ */
+STATIC int
+xrep_dirtree_prep_path(
+ struct xchk_dirtree *dl,
+ struct xchk_dirpath *path,
+ struct xchk_dirpath_step *step)
+{
+ int error;
+
+ error = xfarray_load(dl->path_steps, path->first_step, step);
+ if (error)
+ return error;
+
+ error = xfblob_loadname(dl->path_names, step->name_cookie, &dl->xname,
+ step->name_len);
+ if (error)
+ return error;
+
+ dl->pptr_rec = step->pptr_rec; /* struct copy */
+ return 0;
+}
+
+/* Delete the VFS dentry for a removed child. */
+STATIC int
+xrep_dirtree_purge_dentry(
+ struct xchk_dirtree *dl,
+ struct xfs_inode *dp,
+ const struct xfs_name *name)
+{
+ struct qstr qname = QSTR_INIT(name->name, name->len);
+ struct dentry *parent_dentry, *child_dentry;
+ int error = 0;
+
+ /*
+ * Find the dentry for the parent directory. If there isn't one, we're
+ * done. Caller already holds i_rwsem for parent and child.
+ */
+ parent_dentry = d_find_alias(VFS_I(dp));
+ if (!parent_dentry)
+ return 0;
+
+ /* The VFS thinks the parent is a directory, right? */
+ if (!d_is_dir(parent_dentry)) {
+ ASSERT(d_is_dir(parent_dentry));
+ error = -EFSCORRUPTED;
+ goto out_dput_parent;
+ }
+
+ /*
+ * Try to find the dirent pointing to the child. If there isn't one,
+ * we're done.
+ */
+ qname.hash = full_name_hash(parent_dentry, name->name, name->len);
+ child_dentry = d_lookup(parent_dentry, &qname);
+ if (!child_dentry) {
+ error = 0;
+ goto out_dput_parent;
+ }
+
+ trace_xrep_dirtree_delete_child(dp->i_mount, child_dentry);
+
+ /* Child is not a directory? We're screwed. */
+ if (!d_is_dir(child_dentry)) {
+ ASSERT(d_is_dir(child_dentry));
+ error = -EFSCORRUPTED;
+ goto out_dput_child;
+ }
+
+ /* Replace the child dentry with a negative one. */
+ d_delete(child_dentry);
+
+out_dput_child:
+ dput(child_dentry);
+out_dput_parent:
+ dput(parent_dentry);
+ return error;
+}
+
+/*
+ * Prepare to delete a link by taking the IOLOCK of the parent and the child
+ * (scrub target). Caller must hold IOLOCK_EXCL on @sc->ip. Returns 0 if we
+ * took both locks, or a negative errno if we couldn't lock the parent in time.
+ */
+static inline int
+xrep_dirtree_unlink_iolock(
+ struct xfs_scrub *sc,
+ struct xfs_inode *dp)
+{
+ int error;
+
+ ASSERT(sc->ilock_flags & XFS_IOLOCK_EXCL);
+
+ if (xfs_ilock_nowait(dp, XFS_IOLOCK_EXCL))
+ return 0;
+
+ xchk_iunlock(sc, XFS_IOLOCK_EXCL);
+ do {
+ xfs_ilock(dp, XFS_IOLOCK_EXCL);
+ if (xchk_ilock_nowait(sc, XFS_IOLOCK_EXCL))
+ break;
+ xfs_iunlock(dp, XFS_IOLOCK_EXCL);
+
+ if (xchk_should_terminate(sc, &error)) {
+ xchk_ilock(sc, XFS_IOLOCK_EXCL);
+ return error;
+ }
+
+ delay(1);
+ } while (1);
+
+ return 0;
+}
+
+/*
+ * Remove a link from the directory tree and update the dcache. Returns
+ * -ESTALE if the scan data are now out of date.
+ */
+STATIC int
+xrep_dirtree_unlink(
+ struct xchk_dirtree *dl,
+ struct xfs_inode *dp,
+ struct xchk_dirpath *path,
+ struct xchk_dirpath_step *step)
+{
+ struct xfs_scrub *sc = dl->sc;
+ struct xfs_mount *mp = sc->mp;
+ xfs_ino_t dotdot_ino;
+ xfs_ino_t parent_ino = dl->parent_ino;
+ unsigned int resblks;
+ int dontcare;
+ int error;
+
+ /* Take IOLOCK_EXCL of the parent and child. */
+ error = xrep_dirtree_unlink_iolock(sc, dp);
+ if (error)
+ return error;
+
+ /*
+ * Create the transaction that we need to sever the path. Ignore
+ * EDQUOT and ENOSPC being returned via nospace_error because the
+ * directory code can handle a reservationless update.
+ */
+ resblks = xfs_remove_space_res(mp, step->name_len);
+ error = xfs_trans_alloc_dir(dp, &M_RES(mp)->tr_remove, sc->ip,
+ &resblks, &sc->tp, &dontcare);
+ if (error)
+ goto out_iolock;
+
+ /*
+ * Cancel if someone invalidate the paths while we were trying to get
+ * the ILOCK.
+ */
+ mutex_lock(&dl->lock);
+ if (dl->stale) {
+ mutex_unlock(&dl->lock);
+ error = -ESTALE;
+ goto out_trans_cancel;
+ }
+ xrep_dirpath_set_outcome(dl, path, XREP_DIRPATH_DELETING);
+ mutex_unlock(&dl->lock);
+
+ trace_xrep_dirtree_delete_path(dl->sc, sc->ip, path->path_nr,
+ &dl->xname, &dl->pptr_rec);
+
+ /*
+ * Decide if we need to reset the dotdot entry. Rules:
+ *
+ * - If there's a surviving parent, we want dotdot to point there.
+ * - If we don't have any surviving parents, then point dotdot at the
+ * root dir.
+ * - If dotdot is already set to the value we want, pass in NULLFSINO
+ * for no change necessary.
+ *
+ * Do this /before/ we dirty anything, in case the dotdot lookup
+ * fails.
+ */
+ error = xchk_dir_lookup(sc, sc->ip, &xfs_name_dotdot, &dotdot_ino);
+ if (error)
+ goto out_trans_cancel;
+ if (parent_ino == NULLFSINO)
+ parent_ino = dl->root_ino;
+ if (dotdot_ino == parent_ino)
+ parent_ino = NULLFSINO;
+
+ /* Drop the link from sc->ip's dotdot entry. */
+ error = xfs_droplink(sc->tp, dp);
+ if (error)
+ goto out_trans_cancel;
+
+ /* Reset the dotdot entry to a surviving parent. */
+ if (parent_ino != NULLFSINO) {
+ error = xfs_dir_replace(sc->tp, sc->ip, &xfs_name_dotdot,
+ parent_ino, 0);
+ if (error)
+ goto out_trans_cancel;
+ }
+
+ /* Drop the link from dp to sc->ip. */
+ error = xfs_droplink(sc->tp, sc->ip);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xfs_dir_removename(sc->tp, dp, &dl->xname, sc->ip->i_ino,
+ resblks);
+ if (error) {
+ ASSERT(error != -ENOENT);
+ goto out_trans_cancel;
+ }
+
+ if (xfs_has_parent(sc->mp)) {
+ error = xfs_parent_removename(sc->tp, &dl->ppargs, dp,
+ &dl->xname, sc->ip);
+ if (error)
+ goto out_trans_cancel;
+ }
+
+ /*
+ * Notify dirent hooks that we removed the bad link, invalidate the
+ * dcache, and commit the repair.
+ */
+ xfs_dir_update_hook(dp, sc->ip, -1, &dl->xname);
+ error = xrep_dirtree_purge_dentry(dl, dp, &dl->xname);
+ if (error)
+ goto out_trans_cancel;
+
+ error = xrep_trans_commit(sc);
+ goto out_ilock;
+
+out_trans_cancel:
+ xchk_trans_cancel(sc);
+out_ilock:
+ xfs_iunlock(sc->ip, XFS_ILOCK_EXCL);
+ xfs_iunlock(dp, XFS_ILOCK_EXCL);
+out_iolock:
+ xfs_iunlock(dp, XFS_IOLOCK_EXCL);
+ return error;
+}
+
+/*
+ * Delete a directory entry that points to this directory. Returns -ESTALE
+ * if the scan data are now out of date.
+ */
+STATIC int
+xrep_dirtree_delete_path(
+ struct xchk_dirtree *dl,
+ struct xchk_dirpath *path)
+{
+ struct xchk_dirpath_step step;
+ struct xfs_scrub *sc = dl->sc;
+ struct xfs_inode *dp;
+ int error;
+
+ /*
+ * Load the parent pointer and directory inode for this path, then
+ * drop the scan lock, the ILOCK, and the transaction so that
+ * _delete_path can reserve the proper transaction. This sets up
+ * @dl->xname for the deletion.
+ */
+ error = xrep_dirtree_prep_path(dl, path, &step);
+ if (error)
+ return error;
+
+ error = xchk_iget(sc, be64_to_cpu(step.pptr_rec.p_ino), &dp);
+ if (error)
+ return error;
+
+ mutex_unlock(&dl->lock);
+ xchk_trans_cancel(sc);
+ xchk_iunlock(sc, XFS_ILOCK_EXCL);
+
+ /* Delete the directory link and release the parent. */
+ error = xrep_dirtree_unlink(dl, dp, path, &step);
+ xchk_irele(sc, dp);
+
+ /*
+ * Retake all the resources we had at the beginning even if the repair
+ * failed or the scan data are now stale. This keeps things simple for
+ * the caller.
+ */
+ xchk_trans_alloc_empty(sc);
+ xchk_ilock(sc, XFS_ILOCK_EXCL);
+ mutex_lock(&dl->lock);
+
+ if (!error && dl->stale)
+ error = -ESTALE;
+ return error;
+}
+
+/* Add a new path to represent our in-progress adoption. */
+STATIC int
+xrep_dirtree_create_adoption_path(
+ struct xchk_dirtree *dl)
+{
+ struct xfs_scrub *sc = dl->sc;
+ struct xchk_dirpath *path;
+ int error;
+
+ /*
+ * We should have capped the number of paths at XFS_MAXLINK-1 in the
+ * scanner.
+ */
+ if (dl->nr_paths > XFS_MAXLINK) {
+ ASSERT(dl->nr_paths <= XFS_MAXLINK);
+ return -EFSCORRUPTED;
+ }
+
+ /*
+ * Create a new xchk_path structure to remember this parent pointer
+ * and record the first name step.
+ */
+ path = kmalloc(sizeof(struct xchk_dirpath), XCHK_GFP_FLAGS);
+ if (!path)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&path->list);
+ xino_bitmap_init(&path->seen_inodes);
+ path->nr_steps = 0;
+ path->outcome = XREP_DIRPATH_ADOPTING;
+
+ /*
+ * Record the new link that we just created in the orphanage. Because
+ * adoption is the last repair that we perform, we don't bother filling
+ * in the path all the way back to the root.
+ */
+ xfs_inode_to_parent_rec(&dl->pptr_rec, sc->orphanage);
+
+ error = xino_bitmap_set(&path->seen_inodes, sc->orphanage->i_ino);
+ if (error)
+ goto out_path;
+
+ trace_xrep_dirtree_create_adoption(sc, sc->ip, dl->nr_paths,
+ &dl->xname, &dl->pptr_rec);
+
+ error = xchk_dirpath_append(dl, sc->ip, path, &dl->xname,
+ &dl->pptr_rec);
+ if (error)
+ goto out_path;
+
+ path->first_step = xfarray_length(dl->path_steps) - 1;
+ path->second_step = XFARRAY_NULLIDX;
+ path->path_nr = dl->nr_paths;
+
+ list_add_tail(&path->list, &dl->path_list);
+ dl->nr_paths++;
+ return 0;
+
+out_path:
+ kfree(path);
+ return error;
+}
+
+/*
+ * Prepare to move a file to the orphanage by taking the IOLOCK of the
+ * orphanage and the child (scrub target). Caller must hold IOLOCK_EXCL on
+ * @sc->ip. Returns 0 if we took both locks, or a negative errno if we
+ * couldn't lock the orphanage in time.
+ */
+static inline int
+xrep_dirtree_adopt_iolock(
+ struct xfs_scrub *sc)
+{
+ int error;
+
+ ASSERT(sc->ilock_flags & XFS_IOLOCK_EXCL);
+
+ if (xrep_orphanage_ilock_nowait(sc, XFS_IOLOCK_EXCL))
+ return 0;
+
+ xchk_iunlock(sc, XFS_IOLOCK_EXCL);
+ do {
+ xrep_orphanage_ilock(sc, XFS_IOLOCK_EXCL);
+ if (xchk_ilock_nowait(sc, XFS_IOLOCK_EXCL))
+ break;
+ xrep_orphanage_iunlock(sc, XFS_IOLOCK_EXCL);
+
+ if (xchk_should_terminate(sc, &error)) {
+ xchk_ilock(sc, XFS_IOLOCK_EXCL);
+ return error;
+ }
+
+ delay(1);
+ } while (1);
+
+ return 0;
+}
+
+/*
+ * Reattach this orphaned directory to the orphanage. Do not call this with
+ * any resources held. Returns -ESTALE if the scan data have become out of
+ * date.
+ */
+STATIC int
+xrep_dirtree_adopt(
+ struct xchk_dirtree *dl)
+{
+ struct xfs_scrub *sc = dl->sc;
+ int error;
+
+ /* Take the IOLOCK of the orphanage and the scrub target. */
+ error = xrep_dirtree_adopt_iolock(sc);
+ if (error)
+ return error;
+
+ /*
+ * Set up for an adoption. The directory tree fixer runs after the
+ * link counts have been corrected. Therefore, we must bump the
+ * child's link count since there will be no further opportunity to fix
+ * errors.
+ */
+ error = xrep_adoption_trans_alloc(sc, &dl->adoption);
+ if (error)
+ goto out_iolock;
+ dl->adoption.bump_child_nlink = true;
+
+ /* Figure out what name we're going to use here. */
+ error = xrep_adoption_compute_name(&dl->adoption, &dl->xname);
+ if (error)
+ goto out_trans;
+
+ /*
+ * Now that we have a proposed name for the orphanage entry, create
+ * a faux path so that the live update hook will see it.
+ */
+ mutex_lock(&dl->lock);
+ if (dl->stale) {
+ mutex_unlock(&dl->lock);
+ error = -ESTALE;
+ goto out_trans;
+ }
+ error = xrep_dirtree_create_adoption_path(dl);
+ mutex_unlock(&dl->lock);
+ if (error)
+ goto out_trans;
+
+ /* Reparent the directory. */
+ error = xrep_adoption_move(&dl->adoption);
+ if (error)
+ goto out_trans;
+
+ /*
+ * Commit the name and release all inode locks except for the scrub
+ * target's IOLOCK.
+ */
+ error = xrep_trans_commit(sc);
+ goto out_ilock;
+
+out_trans:
+ xchk_trans_cancel(sc);
+out_ilock:
+ xchk_iunlock(sc, XFS_ILOCK_EXCL);
+ xrep_orphanage_iunlock(sc, XFS_ILOCK_EXCL);
+out_iolock:
+ xrep_orphanage_iunlock(sc, XFS_IOLOCK_EXCL);
+ return error;
+}
+
+/*
+ * This newly orphaned directory needs to be adopted by the orphanage.
+ * Make this happen.
+ */
+STATIC int
+xrep_dirtree_move_to_orphanage(
+ struct xchk_dirtree *dl)
+{
+ struct xfs_scrub *sc = dl->sc;
+ int error;
+
+ /*
+ * Start by dropping all the resources that we hold so that we can grab
+ * all the resources that we need for the adoption.
+ */
+ mutex_unlock(&dl->lock);
+ xchk_trans_cancel(sc);
+ xchk_iunlock(sc, XFS_ILOCK_EXCL);
+
+ /* Perform the adoption. */
+ error = xrep_dirtree_adopt(dl);
+
+ /*
+ * Retake all the resources we had at the beginning even if the repair
+ * failed or the scan data are now stale. This keeps things simple for
+ * the caller.
+ */
+ xchk_trans_alloc_empty(sc);
+ xchk_ilock(sc, XFS_ILOCK_EXCL);
+ mutex_lock(&dl->lock);
+
+ if (!error && dl->stale)
+ error = -ESTALE;
+ return error;
+}
+
+/*
+ * Try to fix all the problems. Returns -ESTALE if the scan data have become
+ * out of date.
+ */
+STATIC int
+xrep_dirtree_fix_problems(
+ struct xchk_dirtree *dl,
+ struct xchk_dirtree_outcomes *oc)
+{
+ struct xchk_dirpath *path;
+ int error;
+
+ /* Delete all the paths we don't want. */
+ xchk_dirtree_for_each_path(dl, path) {
+ if (path->outcome != XCHK_DIRPATH_DELETE)
+ continue;
+
+ error = xrep_dirtree_delete_path(dl, path);
+ if (error)
+ return error;
+ }
+
+ /* Reparent this directory to the orphanage. */
+ if (oc->needs_adoption) {
+ if (xrep_orphanage_can_adopt(dl->sc))
+ return xrep_dirtree_move_to_orphanage(dl);
+ return -EFSCORRUPTED;
+ }
+
+ return 0;
+}
+
+/* Fix directory loops involving this directory. */
+int
+xrep_dirtree(
+ struct xfs_scrub *sc)
+{
+ struct xchk_dirtree *dl = sc->buf;
+ struct xchk_dirtree_outcomes oc;
+ int error;
+
+ /*
+ * Prepare to fix the directory tree by retaking the scan lock. The
+ * order of resource acquisition is still IOLOCK -> transaction ->
+ * ILOCK -> scan lock.
+ */
+ mutex_lock(&dl->lock);
+ do {
+ /*
+ * Decide what we're going to do, then do it. An -ESTALE
+ * return here means the scan results are invalid and we have
+ * to walk again.
+ */
+ if (!dl->stale) {
+ xrep_dirtree_decide_fate(dl, &oc);
+
+ trace_xrep_dirtree_decided_fate(dl, &oc);
+
+ error = xrep_dirtree_fix_problems(dl, &oc);
+ if (!error || error != -ESTALE)
+ break;
+ }
+ error = xchk_dirtree_find_paths_to_root(dl);
+ if (error == -ELNRNG || error == -ENOSR)
+ error = -EFSCORRUPTED;
+ } while (!error);
+ mutex_unlock(&dl->lock);
+
+ return error;
+}