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-rw-r--r--fs/xfs/scrub/parent_repair.c1612
1 files changed, 1612 insertions, 0 deletions
diff --git a/fs/xfs/scrub/parent_repair.c b/fs/xfs/scrub/parent_repair.c
new file mode 100644
index 0000000000..7b42b7f65a
--- /dev/null
+++ b/fs/xfs/scrub/parent_repair.c
@@ -0,0 +1,1612 @@
+// 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_defer.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_trans_space.h"
+#include "xfs_health.h"
+#include "xfs_exchmaps.h"
+#include "xfs_parent.h"
+#include "xfs_attr.h"
+#include "xfs_bmap.h"
+#include "xfs_ag.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/repair.h"
+#include "scrub/iscan.h"
+#include "scrub/findparent.h"
+#include "scrub/readdir.h"
+#include "scrub/tempfile.h"
+#include "scrub/tempexch.h"
+#include "scrub/orphanage.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"
+#include "scrub/xfblob.h"
+#include "scrub/attr_repair.h"
+#include "scrub/listxattr.h"
+
+/*
+ * Repairing The Directory Parent Pointer
+ * ======================================
+ *
+ * Currently, only directories support parent pointers (in the form of '..'
+ * entries), so we simply scan the filesystem and update the '..' entry.
+ *
+ * Note that because the only parent pointer is the dotdot entry, we won't
+ * touch an unhealthy directory, since the directory repair code is perfectly
+ * capable of rebuilding a directory with the proper parent inode.
+ *
+ * See the section on locking issues in dir_repair.c for more information about
+ * conflicts with the VFS. The findparent code wll keep our incore parent
+ * inode up to date.
+ *
+ * If parent pointers are enabled, we instead reconstruct the parent pointer
+ * information by visiting every directory entry of every directory in the
+ * system and translating the relevant dirents into parent pointers. In this
+ * case, it is advantageous to stash all parent pointers created from dirents
+ * from a single parent file before replaying them into the temporary file. To
+ * save memory, the live filesystem scan reuses the findparent object. Parent
+ * pointer repair chooses either directory scanning or findparent, but not
+ * both.
+ *
+ * When salvaging completes, the remaining stashed entries are replayed to the
+ * temporary file. All non-parent pointer extended attributes are copied to
+ * the temporary file's extended attributes. An atomic file mapping exchange
+ * is used to commit the new xattr blocks to the file being repaired. This
+ * will disrupt attrmulti cursors.
+ */
+
+/* Create a parent pointer in the tempfile. */
+#define XREP_PPTR_ADD (1)
+
+/* Remove a parent pointer from the tempfile. */
+#define XREP_PPTR_REMOVE (2)
+
+/* A stashed parent pointer update. */
+struct xrep_pptr {
+ /* Cookie for retrieval of the pptr name. */
+ xfblob_cookie name_cookie;
+
+ /* Parent pointer record. */
+ struct xfs_parent_rec pptr_rec;
+
+ /* Length of the pptr name. */
+ uint8_t namelen;
+
+ /* XREP_PPTR_{ADD,REMOVE} */
+ uint8_t action;
+};
+
+/*
+ * Stash up to 8 pages of recovered parent pointers in pptr_recs and
+ * pptr_names before we write them to the temp file.
+ */
+#define XREP_PARENT_MAX_STASH_BYTES (PAGE_SIZE * 8)
+
+struct xrep_parent {
+ struct xfs_scrub *sc;
+
+ /* Fixed-size array of xrep_pptr structures. */
+ struct xfarray *pptr_recs;
+
+ /* Blobs containing parent pointer names. */
+ struct xfblob *pptr_names;
+
+ /* xattr keys */
+ struct xfarray *xattr_records;
+
+ /* xattr values */
+ struct xfblob *xattr_blobs;
+
+ /* Scratch buffers for saving extended attributes */
+ unsigned char *xattr_name;
+ void *xattr_value;
+ unsigned int xattr_value_sz;
+
+ /*
+ * Information used to exchange the attr fork mappings, if the fs
+ * supports parent pointers.
+ */
+ struct xrep_tempexch tx;
+
+ /*
+ * Information used to scan the filesystem to find the inumber of the
+ * dotdot entry for this directory. On filesystems without parent
+ * pointers, we use the findparent_* functions on this object and
+ * access only the parent_ino field directly.
+ *
+ * When parent pointers are enabled, the directory entry scanner uses
+ * the iscan, hooks, and lock fields of this object directly.
+ * @pscan.lock coordinates access to pptr_recs, pptr_names, pptr, and
+ * pptr_scratch. This reduces the memory requirements of this
+ * structure.
+ *
+ * The lock also controls access to xattr_records and xattr_blobs(?)
+ */
+ struct xrep_parent_scan_info pscan;
+
+ /* Orphanage reparenting request. */
+ struct xrep_adoption adoption;
+
+ /* Directory entry name, plus the trailing null. */
+ struct xfs_name xname;
+ unsigned char namebuf[MAXNAMELEN];
+
+ /* Scratch buffer for scanning pptr xattrs */
+ struct xfs_da_args pptr_args;
+
+ /* Have we seen any live updates of parent pointers recently? */
+ bool saw_pptr_updates;
+
+ /* Number of parents we found after all other repairs */
+ unsigned long long parents;
+};
+
+struct xrep_parent_xattr {
+ /* Cookie for retrieval of the xattr name. */
+ xfblob_cookie name_cookie;
+
+ /* Cookie for retrieval of the xattr value. */
+ xfblob_cookie value_cookie;
+
+ /* XFS_ATTR_* flags */
+ int flags;
+
+ /* Length of the value and name. */
+ uint32_t valuelen;
+ uint16_t namelen;
+};
+
+/*
+ * Stash up to 8 pages of attrs in xattr_records/xattr_blobs before we write
+ * them to the temp file.
+ */
+#define XREP_PARENT_XATTR_MAX_STASH_BYTES (PAGE_SIZE * 8)
+
+/* Tear down all the incore stuff we created. */
+static void
+xrep_parent_teardown(
+ struct xrep_parent *rp)
+{
+ xrep_findparent_scan_teardown(&rp->pscan);
+ kvfree(rp->xattr_name);
+ rp->xattr_name = NULL;
+ kvfree(rp->xattr_value);
+ rp->xattr_value = NULL;
+ if (rp->xattr_blobs)
+ xfblob_destroy(rp->xattr_blobs);
+ rp->xattr_blobs = NULL;
+ if (rp->xattr_records)
+ xfarray_destroy(rp->xattr_records);
+ rp->xattr_records = NULL;
+ if (rp->pptr_names)
+ xfblob_destroy(rp->pptr_names);
+ rp->pptr_names = NULL;
+ if (rp->pptr_recs)
+ xfarray_destroy(rp->pptr_recs);
+ rp->pptr_recs = NULL;
+}
+
+/* Set up for a parent repair. */
+int
+xrep_setup_parent(
+ struct xfs_scrub *sc)
+{
+ struct xrep_parent *rp;
+ int error;
+
+ xchk_fsgates_enable(sc, XCHK_FSGATES_DIRENTS);
+
+ rp = kvzalloc(sizeof(struct xrep_parent), XCHK_GFP_FLAGS);
+ if (!rp)
+ return -ENOMEM;
+ rp->sc = sc;
+ rp->xname.name = rp->namebuf;
+ sc->buf = rp;
+
+ error = xrep_tempfile_create(sc, S_IFREG);
+ if (error)
+ return error;
+
+ return xrep_orphanage_try_create(sc);
+}
+
+/*
+ * Scan all files in the filesystem for a child dirent that we can turn into
+ * the dotdot entry for this directory.
+ */
+STATIC int
+xrep_parent_find_dotdot(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ xfs_ino_t ino;
+ unsigned int sick, checked;
+ int error;
+
+ /*
+ * Avoid sick directories. There shouldn't be anyone else clearing the
+ * directory's sick status.
+ */
+ xfs_inode_measure_sickness(sc->ip, &sick, &checked);
+ if (sick & XFS_SICK_INO_DIR)
+ return -EFSCORRUPTED;
+
+ ino = xrep_findparent_self_reference(sc);
+ if (ino != NULLFSINO) {
+ xrep_findparent_scan_finish_early(&rp->pscan, ino);
+ return 0;
+ }
+
+ /*
+ * Drop the ILOCK on this directory so that we can scan for the dotdot
+ * entry. Figure out who is going to be the parent of this directory,
+ * then retake the ILOCK so that we can salvage directory entries.
+ */
+ xchk_iunlock(sc, XFS_ILOCK_EXCL);
+
+ /* Does the VFS dcache have an answer for us? */
+ ino = xrep_findparent_from_dcache(sc);
+ if (ino != NULLFSINO) {
+ error = xrep_findparent_confirm(sc, &ino);
+ if (!error && ino != NULLFSINO) {
+ xrep_findparent_scan_finish_early(&rp->pscan, ino);
+ goto out_relock;
+ }
+ }
+
+ /* Scan the entire filesystem for a parent. */
+ error = xrep_findparent_scan(&rp->pscan);
+out_relock:
+ xchk_ilock(sc, XFS_ILOCK_EXCL);
+
+ return error;
+}
+
+/*
+ * Add this stashed incore parent pointer to the temporary file.
+ * The caller must hold the tempdir's IOLOCK, must not hold any ILOCKs, and
+ * must not be in transaction context.
+ */
+STATIC int
+xrep_parent_replay_update(
+ struct xrep_parent *rp,
+ const struct xfs_name *xname,
+ struct xrep_pptr *pptr)
+{
+ struct xfs_scrub *sc = rp->sc;
+
+ switch (pptr->action) {
+ case XREP_PPTR_ADD:
+ /* Create parent pointer. */
+ trace_xrep_parent_replay_parentadd(sc->tempip, xname,
+ &pptr->pptr_rec);
+
+ return xfs_parent_set(sc->tempip, sc->ip->i_ino, xname,
+ &pptr->pptr_rec, &rp->pptr_args);
+ case XREP_PPTR_REMOVE:
+ /* Remove parent pointer. */
+ trace_xrep_parent_replay_parentremove(sc->tempip, xname,
+ &pptr->pptr_rec);
+
+ return xfs_parent_unset(sc->tempip, sc->ip->i_ino, xname,
+ &pptr->pptr_rec, &rp->pptr_args);
+ }
+
+ ASSERT(0);
+ return -EIO;
+}
+
+/*
+ * Flush stashed parent pointer updates that have been recorded by the scanner.
+ * This is done to reduce the memory requirements of the parent pointer
+ * rebuild, since files can have a lot of hardlinks and the fs can be busy.
+ *
+ * Caller must not hold transactions or ILOCKs. Caller must hold the tempfile
+ * IOLOCK.
+ */
+STATIC int
+xrep_parent_replay_updates(
+ struct xrep_parent *rp)
+{
+ xfarray_idx_t array_cur;
+ int error;
+
+ mutex_lock(&rp->pscan.lock);
+ foreach_xfarray_idx(rp->pptr_recs, array_cur) {
+ struct xrep_pptr pptr;
+
+ error = xfarray_load(rp->pptr_recs, array_cur, &pptr);
+ if (error)
+ goto out_unlock;
+
+ error = xfblob_loadname(rp->pptr_names, pptr.name_cookie,
+ &rp->xname, pptr.namelen);
+ if (error)
+ goto out_unlock;
+ rp->xname.len = pptr.namelen;
+ mutex_unlock(&rp->pscan.lock);
+
+ error = xrep_parent_replay_update(rp, &rp->xname, &pptr);
+ if (error)
+ return error;
+
+ mutex_lock(&rp->pscan.lock);
+ }
+
+ /* Empty out both arrays now that we've added the entries. */
+ xfarray_truncate(rp->pptr_recs);
+ xfblob_truncate(rp->pptr_names);
+ mutex_unlock(&rp->pscan.lock);
+ return 0;
+out_unlock:
+ mutex_unlock(&rp->pscan.lock);
+ return error;
+}
+
+/*
+ * Remember that we want to create a parent pointer in the tempfile. These
+ * stashed actions will be replayed later.
+ */
+STATIC int
+xrep_parent_stash_parentadd(
+ struct xrep_parent *rp,
+ const struct xfs_name *name,
+ const struct xfs_inode *dp)
+{
+ struct xrep_pptr pptr = {
+ .action = XREP_PPTR_ADD,
+ .namelen = name->len,
+ };
+ int error;
+
+ trace_xrep_parent_stash_parentadd(rp->sc->tempip, dp, name);
+
+ xfs_inode_to_parent_rec(&pptr.pptr_rec, dp);
+ error = xfblob_storename(rp->pptr_names, &pptr.name_cookie, name);
+ if (error)
+ return error;
+
+ return xfarray_append(rp->pptr_recs, &pptr);
+}
+
+/*
+ * Remember that we want to remove a parent pointer from the tempfile. These
+ * stashed actions will be replayed later.
+ */
+STATIC int
+xrep_parent_stash_parentremove(
+ struct xrep_parent *rp,
+ const struct xfs_name *name,
+ const struct xfs_inode *dp)
+{
+ struct xrep_pptr pptr = {
+ .action = XREP_PPTR_REMOVE,
+ .namelen = name->len,
+ };
+ int error;
+
+ trace_xrep_parent_stash_parentremove(rp->sc->tempip, dp, name);
+
+ xfs_inode_to_parent_rec(&pptr.pptr_rec, dp);
+ error = xfblob_storename(rp->pptr_names, &pptr.name_cookie, name);
+ if (error)
+ return error;
+
+ return xfarray_append(rp->pptr_recs, &pptr);
+}
+
+/*
+ * Examine an entry of a directory. If this dirent leads us back to the file
+ * whose parent pointers we're rebuilding, add a pptr to the temporary
+ * directory.
+ */
+STATIC int
+xrep_parent_scan_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 xrep_parent *rp = priv;
+ int error;
+
+ /* Dirent doesn't point to this directory. */
+ if (ino != rp->sc->ip->i_ino)
+ return 0;
+
+ /* No weird looking names. */
+ if (name->len == 0 || !xfs_dir2_namecheck(name->name, name->len))
+ return -EFSCORRUPTED;
+
+ /* No mismatching ftypes. */
+ if (name->type != xfs_mode_to_ftype(VFS_I(sc->ip)->i_mode))
+ return -EFSCORRUPTED;
+
+ /* Don't pick up dot or dotdot entries; we only want child dirents. */
+ if (xfs_dir2_samename(name, &xfs_name_dotdot) ||
+ xfs_dir2_samename(name, &xfs_name_dot))
+ return 0;
+
+ /*
+ * Transform this dirent into a parent pointer and queue it for later
+ * addition to the temporary file.
+ */
+ mutex_lock(&rp->pscan.lock);
+ error = xrep_parent_stash_parentadd(rp, name, dp);
+ mutex_unlock(&rp->pscan.lock);
+ return error;
+}
+
+/*
+ * Decide if we want to look for dirents in this directory. Skip the file
+ * being repaired and any files being used to stage repairs.
+ */
+static inline bool
+xrep_parent_want_scan(
+ struct xrep_parent *rp,
+ const struct xfs_inode *ip)
+{
+ return ip != rp->sc->ip && !xrep_is_tempfile(ip);
+}
+
+/*
+ * Take ILOCK on a file that we want to scan.
+ *
+ * Select ILOCK_EXCL if the file is a directory with an unloaded data bmbt.
+ * Otherwise, take ILOCK_SHARED.
+ */
+static inline unsigned int
+xrep_parent_scan_ilock(
+ struct xrep_parent *rp,
+ struct xfs_inode *ip)
+{
+ uint lock_mode = XFS_ILOCK_SHARED;
+
+ /* Still need to take the shared ILOCK to advance the iscan cursor. */
+ if (!xrep_parent_want_scan(rp, ip))
+ goto lock;
+
+ if (S_ISDIR(VFS_I(ip)->i_mode) && xfs_need_iread_extents(&ip->i_df)) {
+ lock_mode = XFS_ILOCK_EXCL;
+ goto lock;
+ }
+
+lock:
+ xfs_ilock(ip, lock_mode);
+ return lock_mode;
+}
+
+/*
+ * Scan this file for relevant child dirents that point to the file whose
+ * parent pointers we're rebuilding.
+ */
+STATIC int
+xrep_parent_scan_file(
+ struct xrep_parent *rp,
+ struct xfs_inode *ip)
+{
+ unsigned int lock_mode;
+ int error = 0;
+
+ lock_mode = xrep_parent_scan_ilock(rp, ip);
+
+ if (!xrep_parent_want_scan(rp, ip))
+ goto scan_done;
+
+ if (S_ISDIR(VFS_I(ip)->i_mode)) {
+ /*
+ * If the directory looks as though it has been zapped by the
+ * inode record repair code, we cannot scan for child dirents.
+ */
+ if (xchk_dir_looks_zapped(ip)) {
+ error = -EBUSY;
+ goto scan_done;
+ }
+
+ error = xchk_dir_walk(rp->sc, ip, xrep_parent_scan_dirent, rp);
+ if (error)
+ goto scan_done;
+ }
+
+scan_done:
+ xchk_iscan_mark_visited(&rp->pscan.iscan, ip);
+ xfs_iunlock(ip, lock_mode);
+ return error;
+}
+
+/* Decide if we've stashed too much pptr data in memory. */
+static inline bool
+xrep_parent_want_flush_stashed(
+ struct xrep_parent *rp)
+{
+ unsigned long long bytes;
+
+ bytes = xfarray_bytes(rp->pptr_recs) + xfblob_bytes(rp->pptr_names);
+ return bytes > XREP_PARENT_MAX_STASH_BYTES;
+}
+
+/*
+ * Scan all directories in the filesystem to look for dirents that we can turn
+ * into parent pointers.
+ */
+STATIC int
+xrep_parent_scan_dirtree(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ struct xfs_inode *ip;
+ int error;
+
+ /*
+ * Filesystem scans are time consuming. Drop the file ILOCK and all
+ * other resources for the duration of the scan and hope for the best.
+ * The live update hooks will keep our scan information up to date.
+ */
+ xchk_trans_cancel(sc);
+ if (sc->ilock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL))
+ xchk_iunlock(sc, sc->ilock_flags & (XFS_ILOCK_SHARED |
+ XFS_ILOCK_EXCL));
+ error = xchk_trans_alloc_empty(sc);
+ if (error)
+ return error;
+
+ while ((error = xchk_iscan_iter(&rp->pscan.iscan, &ip)) == 1) {
+ bool flush;
+
+ error = xrep_parent_scan_file(rp, ip);
+ xchk_irele(sc, ip);
+ if (error)
+ break;
+
+ /* Flush stashed pptr updates to constrain memory usage. */
+ mutex_lock(&rp->pscan.lock);
+ flush = xrep_parent_want_flush_stashed(rp);
+ mutex_unlock(&rp->pscan.lock);
+ if (flush) {
+ xchk_trans_cancel(sc);
+
+ error = xrep_tempfile_iolock_polled(sc);
+ if (error)
+ break;
+
+ error = xrep_parent_replay_updates(rp);
+ xrep_tempfile_iounlock(sc);
+ if (error)
+ break;
+
+ error = xchk_trans_alloc_empty(sc);
+ if (error)
+ break;
+ }
+
+ if (xchk_should_terminate(sc, &error))
+ break;
+ }
+ xchk_iscan_iter_finish(&rp->pscan.iscan);
+ if (error) {
+ /*
+ * 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;
+ }
+
+ /*
+ * Retake sc->ip's ILOCK now that we're done flushing stashed parent
+ * pointers. We end this function with an empty transaction and the
+ * ILOCK.
+ */
+ xchk_ilock(rp->sc, XFS_ILOCK_EXCL);
+ return 0;
+}
+
+/*
+ * Capture dirent updates being made by other threads which are relevant to the
+ * file being repaired.
+ */
+STATIC int
+xrep_parent_live_update(
+ struct notifier_block *nb,
+ unsigned long action,
+ void *data)
+{
+ struct xfs_dir_update_params *p = data;
+ struct xrep_parent *rp;
+ struct xfs_scrub *sc;
+ int error;
+
+ rp = container_of(nb, struct xrep_parent, pscan.dhook.dirent_hook.nb);
+ sc = rp->sc;
+
+ /*
+ * This thread updated a dirent that points to the file that we're
+ * repairing, so stash the update for replay against the temporary
+ * file.
+ */
+ if (p->ip->i_ino == sc->ip->i_ino &&
+ xchk_iscan_want_live_update(&rp->pscan.iscan, p->dp->i_ino)) {
+ mutex_lock(&rp->pscan.lock);
+ if (p->delta > 0)
+ error = xrep_parent_stash_parentadd(rp, p->name, p->dp);
+ else
+ error = xrep_parent_stash_parentremove(rp, p->name,
+ p->dp);
+ if (!error)
+ rp->saw_pptr_updates = true;
+ mutex_unlock(&rp->pscan.lock);
+ if (error)
+ goto out_abort;
+ }
+
+ return NOTIFY_DONE;
+out_abort:
+ xchk_iscan_abort(&rp->pscan.iscan);
+ return NOTIFY_DONE;
+}
+
+/* Reset a directory's dotdot entry, if needed. */
+STATIC int
+xrep_parent_reset_dotdot(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ xfs_ino_t ino;
+ unsigned int spaceres;
+ int error = 0;
+
+ ASSERT(sc->ilock_flags & XFS_ILOCK_EXCL);
+
+ error = xchk_dir_lookup(sc, sc->ip, &xfs_name_dotdot, &ino);
+ if (error || ino == rp->pscan.parent_ino)
+ return error;
+
+ xfs_trans_ijoin(sc->tp, sc->ip, 0);
+
+ trace_xrep_parent_reset_dotdot(sc->ip, rp->pscan.parent_ino);
+
+ /*
+ * Reserve more space just in case we have to expand the dir. We're
+ * allowed to exceed quota to repair inconsistent metadata.
+ */
+ spaceres = xfs_rename_space_res(sc->mp, 0, false, xfs_name_dotdot.len,
+ false);
+ error = xfs_trans_reserve_more_inode(sc->tp, sc->ip, spaceres, 0,
+ true);
+ if (error)
+ return error;
+
+ error = xfs_dir_replace(sc->tp, sc->ip, &xfs_name_dotdot,
+ rp->pscan.parent_ino, spaceres);
+ if (error)
+ return error;
+
+ /*
+ * Roll transaction to detach the inode from the transaction but retain
+ * ILOCK_EXCL.
+ */
+ return xfs_trans_roll(&sc->tp);
+}
+
+/* Pass back the parent inumber if this a parent pointer */
+STATIC int
+xrep_parent_lookup_pptr(
+ struct xfs_scrub *sc,
+ struct xfs_inode *ip,
+ unsigned int attr_flags,
+ const unsigned char *name,
+ unsigned int namelen,
+ const void *value,
+ unsigned int valuelen,
+ void *priv)
+{
+ xfs_ino_t *inop = priv;
+ xfs_ino_t parent_ino;
+ int error;
+
+ if (!(attr_flags & XFS_ATTR_PARENT))
+ return 0;
+
+ error = xfs_parent_from_attr(sc->mp, attr_flags, name, namelen, value,
+ valuelen, &parent_ino, NULL);
+ if (error)
+ return error;
+
+ *inop = parent_ino;
+ return -ECANCELED;
+}
+
+/*
+ * Find the first parent of the scrub target by walking parent pointers for
+ * the purpose of deciding if we're going to move it to the orphanage.
+ * We don't care if the attr fork is zapped.
+ */
+STATIC int
+xrep_parent_lookup_pptrs(
+ struct xfs_scrub *sc,
+ xfs_ino_t *inop)
+{
+ int error;
+
+ *inop = NULLFSINO;
+
+ error = xchk_xattr_walk(sc, sc->ip, xrep_parent_lookup_pptr, NULL,
+ inop);
+ if (error && error != -ECANCELED)
+ return error;
+ return 0;
+}
+
+/*
+ * Move the current file to the orphanage.
+ *
+ * Caller must hold IOLOCK_EXCL on @sc->ip, and no other inode locks. Upon
+ * successful return, the scrub transaction will have enough extra reservation
+ * to make the move; it will hold IOLOCK_EXCL and ILOCK_EXCL of @sc->ip and the
+ * orphanage; and both inodes will be ijoined.
+ */
+STATIC int
+xrep_parent_move_to_orphanage(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ xfs_ino_t orig_parent, new_parent;
+ int error;
+
+ if (S_ISDIR(VFS_I(sc->ip)->i_mode)) {
+ /*
+ * We are about to drop the ILOCK on sc->ip to lock the
+ * orphanage and prepare for the adoption. Therefore, look up
+ * the old dotdot entry for sc->ip so that we can compare it
+ * after we re-lock sc->ip.
+ */
+ error = xchk_dir_lookup(sc, sc->ip, &xfs_name_dotdot,
+ &orig_parent);
+ if (error)
+ return error;
+ } else {
+ /*
+ * We haven't dropped the ILOCK since we committed the new
+ * xattr structure (and hence the new parent pointer records),
+ * which means that the file cannot have been moved in the
+ * directory tree, and there are no parents.
+ */
+ orig_parent = NULLFSINO;
+ }
+
+ /*
+ * Drop the ILOCK on the scrub target and commit the transaction.
+ * Adoption computes its own resource requirements and gathers the
+ * necessary components.
+ */
+ error = xrep_trans_commit(sc);
+ if (error)
+ return error;
+ xchk_iunlock(sc, XFS_ILOCK_EXCL);
+
+ /* If we can take the orphanage's iolock then we're ready to move. */
+ if (!xrep_orphanage_ilock_nowait(sc, XFS_IOLOCK_EXCL)) {
+ xchk_iunlock(sc, sc->ilock_flags);
+ error = xrep_orphanage_iolock_two(sc);
+ if (error)
+ return error;
+ }
+
+ /* Grab transaction and ILOCK the two files. */
+ error = xrep_adoption_trans_alloc(sc, &rp->adoption);
+ if (error)
+ return error;
+
+ error = xrep_adoption_compute_name(&rp->adoption, &rp->xname);
+ if (error)
+ return error;
+
+ /*
+ * Now that we've reacquired the ILOCK on sc->ip, look up the dotdot
+ * entry again. If the parent changed or the child was unlinked while
+ * the child directory was unlocked, we don't need to move the child to
+ * the orphanage after all. For a non-directory, we have to scan for
+ * the first parent pointer to see if one has been added.
+ */
+ if (S_ISDIR(VFS_I(sc->ip)->i_mode))
+ error = xchk_dir_lookup(sc, sc->ip, &xfs_name_dotdot,
+ &new_parent);
+ else
+ error = xrep_parent_lookup_pptrs(sc, &new_parent);
+ if (error)
+ return error;
+
+ /*
+ * Attach to the orphanage if we still have a linked directory and it
+ * hasn't been moved.
+ */
+ if (orig_parent == new_parent && VFS_I(sc->ip)->i_nlink > 0) {
+ error = xrep_adoption_move(&rp->adoption);
+ if (error)
+ return error;
+ }
+
+ /*
+ * Launder the scrub transaction so we can drop the orphanage ILOCK
+ * and IOLOCK. Return holding the scrub target's ILOCK and IOLOCK.
+ */
+ error = xrep_adoption_trans_roll(&rp->adoption);
+ if (error)
+ return error;
+
+ xrep_orphanage_iunlock(sc, XFS_ILOCK_EXCL);
+ xrep_orphanage_iunlock(sc, XFS_IOLOCK_EXCL);
+ return 0;
+}
+
+/* Ensure that the xattr value buffer is large enough. */
+STATIC int
+xrep_parent_alloc_xattr_value(
+ struct xrep_parent *rp,
+ size_t bufsize)
+{
+ void *new_val;
+
+ if (rp->xattr_value_sz >= bufsize)
+ return 0;
+
+ if (rp->xattr_value) {
+ kvfree(rp->xattr_value);
+ rp->xattr_value = NULL;
+ rp->xattr_value_sz = 0;
+ }
+
+ new_val = kvmalloc(bufsize, XCHK_GFP_FLAGS);
+ if (!new_val)
+ return -ENOMEM;
+
+ rp->xattr_value = new_val;
+ rp->xattr_value_sz = bufsize;
+ return 0;
+}
+
+/* Retrieve the (remote) value of a non-pptr xattr. */
+STATIC int
+xrep_parent_fetch_xattr_remote(
+ struct xrep_parent *rp,
+ struct xfs_inode *ip,
+ unsigned int attr_flags,
+ const unsigned char *name,
+ unsigned int namelen,
+ unsigned int valuelen)
+{
+ struct xfs_scrub *sc = rp->sc;
+ struct xfs_da_args args = {
+ .attr_filter = attr_flags & XFS_ATTR_NSP_ONDISK_MASK,
+ .geo = sc->mp->m_attr_geo,
+ .whichfork = XFS_ATTR_FORK,
+ .dp = ip,
+ .name = name,
+ .namelen = namelen,
+ .trans = sc->tp,
+ .valuelen = valuelen,
+ .owner = ip->i_ino,
+ };
+ int error;
+
+ /*
+ * If we need a larger value buffer, try to allocate one. If that
+ * fails, return with -EDEADLOCK to try harder.
+ */
+ error = xrep_parent_alloc_xattr_value(rp, valuelen);
+ if (error == -ENOMEM)
+ return -EDEADLOCK;
+ if (error)
+ return error;
+
+ args.value = rp->xattr_value;
+ xfs_attr_sethash(&args);
+ return xfs_attr_get_ilocked(&args);
+}
+
+/* Stash non-pptr attributes for later replay into the temporary file. */
+STATIC int
+xrep_parent_stash_xattr(
+ struct xfs_scrub *sc,
+ struct xfs_inode *ip,
+ unsigned int attr_flags,
+ const unsigned char *name,
+ unsigned int namelen,
+ const void *value,
+ unsigned int valuelen,
+ void *priv)
+{
+ struct xrep_parent_xattr key = {
+ .valuelen = valuelen,
+ .namelen = namelen,
+ .flags = attr_flags & XFS_ATTR_NSP_ONDISK_MASK,
+ };
+ struct xrep_parent *rp = priv;
+ int error;
+
+ if (attr_flags & (XFS_ATTR_INCOMPLETE | XFS_ATTR_PARENT))
+ return 0;
+
+ if (!value) {
+ error = xrep_parent_fetch_xattr_remote(rp, ip, attr_flags,
+ name, namelen, valuelen);
+ if (error)
+ return error;
+
+ value = rp->xattr_value;
+ }
+
+ trace_xrep_parent_stash_xattr(rp->sc->tempip, key.flags, (void *)name,
+ key.namelen, key.valuelen);
+
+ error = xfblob_store(rp->xattr_blobs, &key.name_cookie, name,
+ key.namelen);
+ if (error)
+ return error;
+
+ error = xfblob_store(rp->xattr_blobs, &key.value_cookie, value,
+ key.valuelen);
+ if (error)
+ return error;
+
+ return xfarray_append(rp->xattr_records, &key);
+}
+
+/* Insert one xattr key/value. */
+STATIC int
+xrep_parent_insert_xattr(
+ struct xrep_parent *rp,
+ const struct xrep_parent_xattr *key)
+{
+ struct xfs_da_args args = {
+ .dp = rp->sc->tempip,
+ .attr_filter = key->flags,
+ .namelen = key->namelen,
+ .valuelen = key->valuelen,
+ .owner = rp->sc->ip->i_ino,
+ .geo = rp->sc->mp->m_attr_geo,
+ .whichfork = XFS_ATTR_FORK,
+ .op_flags = XFS_DA_OP_OKNOENT,
+ };
+ int error;
+
+ ASSERT(!(key->flags & XFS_ATTR_PARENT));
+
+ /*
+ * Grab pointers to the scrub buffer so that we can use them to insert
+ * attrs into the temp file.
+ */
+ args.name = rp->xattr_name;
+ args.value = rp->xattr_value;
+
+ /*
+ * The attribute name is stored near the end of the in-core buffer,
+ * though we reserve one more byte to ensure null termination.
+ */
+ rp->xattr_name[XATTR_NAME_MAX] = 0;
+
+ error = xfblob_load(rp->xattr_blobs, key->name_cookie, rp->xattr_name,
+ key->namelen);
+ if (error)
+ return error;
+
+ error = xfblob_free(rp->xattr_blobs, key->name_cookie);
+ if (error)
+ return error;
+
+ error = xfblob_load(rp->xattr_blobs, key->value_cookie, args.value,
+ key->valuelen);
+ if (error)
+ return error;
+
+ error = xfblob_free(rp->xattr_blobs, key->value_cookie);
+ if (error)
+ return error;
+
+ rp->xattr_name[key->namelen] = 0;
+
+ trace_xrep_parent_insert_xattr(rp->sc->tempip, key->flags,
+ rp->xattr_name, key->namelen, key->valuelen);
+
+ xfs_attr_sethash(&args);
+ return xfs_attr_set(&args, XFS_ATTRUPDATE_UPSERT, false);
+}
+
+/*
+ * Periodically flush salvaged attributes to the temporary file. This is done
+ * to reduce the memory requirements of the xattr rebuild because files can
+ * contain millions of attributes.
+ */
+STATIC int
+xrep_parent_flush_xattrs(
+ struct xrep_parent *rp)
+{
+ xfarray_idx_t array_cur;
+ int error;
+
+ /*
+ * Entering this function, the scrub context has a reference to the
+ * inode being repaired, the temporary file, and the empty scrub
+ * transaction that we created for the xattr scan. We hold ILOCK_EXCL
+ * on the inode being repaired.
+ *
+ * To constrain kernel memory use, we occasionally flush salvaged
+ * xattrs from the xfarray and xfblob structures into the temporary
+ * file in preparation for exchanging the xattr structures at the end.
+ * Updating the temporary file requires a transaction, so we commit the
+ * scrub transaction and drop the ILOCK so that xfs_attr_set can
+ * allocate whatever transaction it wants.
+ *
+ * We still hold IOLOCK_EXCL on the inode being repaired, which
+ * prevents anyone from adding xattrs (or parent pointers) while we're
+ * flushing.
+ */
+ xchk_trans_cancel(rp->sc);
+ xchk_iunlock(rp->sc, XFS_ILOCK_EXCL);
+
+ /*
+ * Take the IOLOCK of the temporary file while we modify xattrs. This
+ * isn't strictly required because the temporary file is never revealed
+ * to userspace, but we follow the same locking rules. We still hold
+ * sc->ip's IOLOCK.
+ */
+ error = xrep_tempfile_iolock_polled(rp->sc);
+ if (error)
+ return error;
+
+ /* Add all the salvaged attrs to the temporary file. */
+ foreach_xfarray_idx(rp->xattr_records, array_cur) {
+ struct xrep_parent_xattr key;
+
+ error = xfarray_load(rp->xattr_records, array_cur, &key);
+ if (error)
+ return error;
+
+ error = xrep_parent_insert_xattr(rp, &key);
+ if (error)
+ return error;
+ }
+
+ /* Empty out both arrays now that we've added the entries. */
+ xfarray_truncate(rp->xattr_records);
+ xfblob_truncate(rp->xattr_blobs);
+
+ xrep_tempfile_iounlock(rp->sc);
+
+ /* Recreate the empty transaction and relock the inode. */
+ error = xchk_trans_alloc_empty(rp->sc);
+ if (error)
+ return error;
+ xchk_ilock(rp->sc, XFS_ILOCK_EXCL);
+ return 0;
+}
+
+/* Decide if we've stashed too much xattr data in memory. */
+static inline bool
+xrep_parent_want_flush_xattrs(
+ struct xrep_parent *rp)
+{
+ unsigned long long bytes;
+
+ bytes = xfarray_bytes(rp->xattr_records) +
+ xfblob_bytes(rp->xattr_blobs);
+ return bytes > XREP_PARENT_XATTR_MAX_STASH_BYTES;
+}
+
+/* Flush staged attributes to the temporary file if we're over the limit. */
+STATIC int
+xrep_parent_try_flush_xattrs(
+ struct xfs_scrub *sc,
+ void *priv)
+{
+ struct xrep_parent *rp = priv;
+ int error;
+
+ if (!xrep_parent_want_flush_xattrs(rp))
+ return 0;
+
+ error = xrep_parent_flush_xattrs(rp);
+ if (error)
+ return error;
+
+ /*
+ * If there were any parent pointer updates to the xattr structure
+ * while we dropped the ILOCK, the xattr structure is now stale.
+ * Signal to the attr copy process that we need to start over, but
+ * this time without opportunistic attr flushing.
+ *
+ * This is unlikely to happen, so we're ok with restarting the copy.
+ */
+ mutex_lock(&rp->pscan.lock);
+ if (rp->saw_pptr_updates)
+ error = -ESTALE;
+ mutex_unlock(&rp->pscan.lock);
+ return error;
+}
+
+/* Copy all the non-pptr extended attributes into the temporary file. */
+STATIC int
+xrep_parent_copy_xattrs(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ int error;
+
+ /*
+ * Clear the pptr updates flag. We hold sc->ip ILOCKed, so there
+ * can't be any parent pointer updates in progress.
+ */
+ mutex_lock(&rp->pscan.lock);
+ rp->saw_pptr_updates = false;
+ mutex_unlock(&rp->pscan.lock);
+
+ /* Copy xattrs, stopping periodically to flush the incore buffers. */
+ error = xchk_xattr_walk(sc, sc->ip, xrep_parent_stash_xattr,
+ xrep_parent_try_flush_xattrs, rp);
+ if (error && error != -ESTALE)
+ return error;
+
+ if (error == -ESTALE) {
+ /*
+ * The xattr copy collided with a parent pointer update.
+ * Restart the copy, but this time hold the ILOCK all the way
+ * to the end to lock out any directory parent pointer updates.
+ */
+ error = xchk_xattr_walk(sc, sc->ip, xrep_parent_stash_xattr,
+ NULL, rp);
+ if (error)
+ return error;
+ }
+
+ /* Flush any remaining stashed xattrs to the temporary file. */
+ if (xfarray_bytes(rp->xattr_records) == 0)
+ return 0;
+
+ return xrep_parent_flush_xattrs(rp);
+}
+
+/*
+ * Ensure that @sc->ip and @sc->tempip both have attribute forks before we head
+ * into the attr fork exchange transaction. All files on a filesystem with
+ * parent pointers must have an attr fork because the parent pointer code does
+ * not itself add attribute forks.
+ *
+ * Note: Unlinkable unlinked files don't need one, but the overhead of having
+ * an unnecessary attr fork is not justified by the additional code complexity
+ * that would be needed to track that state correctly.
+ */
+STATIC int
+xrep_parent_ensure_attr_fork(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ int error;
+
+ error = xfs_attr_add_fork(sc->tempip,
+ sizeof(struct xfs_attr_sf_hdr), 1);
+ if (error)
+ return error;
+ return xfs_attr_add_fork(sc->ip, sizeof(struct xfs_attr_sf_hdr), 1);
+}
+
+/*
+ * Finish replaying stashed parent pointer updates, allocate a transaction for
+ * exchanging extent mappings, and take the ILOCKs of both files before we
+ * commit the new attribute structure.
+ */
+STATIC int
+xrep_parent_finalize_tempfile(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ int error;
+
+ /*
+ * Repair relies on the ILOCK to quiesce all possible xattr updates.
+ * Replay all queued parent pointer updates into the tempfile before
+ * exchanging the contents, even if that means dropping the ILOCKs and
+ * the transaction.
+ */
+ do {
+ error = xrep_parent_replay_updates(rp);
+ if (error)
+ return error;
+
+ error = xrep_parent_ensure_attr_fork(rp);
+ if (error)
+ return error;
+
+ error = xrep_tempexch_trans_alloc(sc, XFS_ATTR_FORK, &rp->tx);
+ if (error)
+ return error;
+
+ if (xfarray_length(rp->pptr_recs) == 0)
+ break;
+
+ xchk_trans_cancel(sc);
+ xrep_tempfile_iunlock_both(sc);
+ } while (!xchk_should_terminate(sc, &error));
+ return error;
+}
+
+/*
+ * Replay all the stashed parent pointers into the temporary file, copy all
+ * the non-pptr xattrs from the file being repaired into the temporary file,
+ * and exchange the attr fork contents atomically.
+ */
+STATIC int
+xrep_parent_rebuild_pptrs(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ xfs_ino_t parent_ino = NULLFSINO;
+ int error;
+
+ /*
+ * Copy non-ppttr xattrs from the file being repaired into the
+ * temporary file's xattr structure. We hold sc->ip's IOLOCK, which
+ * prevents setxattr/removexattr calls from occurring, but renames
+ * update the parent pointers without holding IOLOCK. If we detect
+ * stale attr structures, we restart the scan but only flush at the
+ * end.
+ */
+ error = xrep_parent_copy_xattrs(rp);
+ if (error)
+ return error;
+
+ /*
+ * Cancel the empty transaction that we used to walk and copy attrs,
+ * and drop the ILOCK so that we can take the IOLOCK on the temporary
+ * file. We still hold sc->ip's IOLOCK.
+ */
+ xchk_trans_cancel(sc);
+ xchk_iunlock(sc, XFS_ILOCK_EXCL);
+
+ error = xrep_tempfile_iolock_polled(sc);
+ if (error)
+ return error;
+
+ /*
+ * Allocate transaction, lock inodes, and make sure that we've replayed
+ * all the stashed pptr updates to the tempdir. After this point,
+ * we're ready to exchange the attr fork mappings.
+ */
+ error = xrep_parent_finalize_tempfile(rp);
+ if (error)
+ return error;
+
+ /* Last chance to abort before we start committing pptr fixes. */
+ if (xchk_should_terminate(sc, &error))
+ return error;
+
+ if (xchk_iscan_aborted(&rp->pscan.iscan))
+ return -ECANCELED;
+
+ /*
+ * Exchange the attr fork contents and junk the old attr fork contents,
+ * which are now in the tempfile.
+ */
+ error = xrep_xattr_swap(sc, &rp->tx);
+ if (error)
+ return error;
+ error = xrep_xattr_reset_tempfile_fork(sc);
+ if (error)
+ return error;
+
+ /*
+ * Roll to get a transaction without any inodes joined to it. Then we
+ * can drop the tempfile's ILOCK and IOLOCK before doing more work on
+ * the scrub target file.
+ */
+ error = xfs_trans_roll(&sc->tp);
+ if (error)
+ return error;
+ xrep_tempfile_iunlock(sc);
+ xrep_tempfile_iounlock(sc);
+
+ /*
+ * We've committed the new parent pointers. Find at least one parent
+ * so that we can decide if we're moving this file to the orphanage.
+ * For this purpose, root directories are their own parents.
+ */
+ if (sc->ip == sc->mp->m_rootip) {
+ xrep_findparent_scan_found(&rp->pscan, sc->ip->i_ino);
+ } else {
+ error = xrep_parent_lookup_pptrs(sc, &parent_ino);
+ if (error)
+ return error;
+ if (parent_ino != NULLFSINO)
+ xrep_findparent_scan_found(&rp->pscan, parent_ino);
+ }
+ return 0;
+}
+
+/*
+ * Commit the new parent pointer structure (currently only the dotdot entry) to
+ * the file that we're repairing.
+ */
+STATIC int
+xrep_parent_rebuild_tree(
+ struct xrep_parent *rp)
+{
+ int error;
+
+ if (xfs_has_parent(rp->sc->mp)) {
+ error = xrep_parent_rebuild_pptrs(rp);
+ if (error)
+ return error;
+ }
+
+ if (rp->pscan.parent_ino == NULLFSINO) {
+ if (xrep_orphanage_can_adopt(rp->sc))
+ return xrep_parent_move_to_orphanage(rp);
+ return -EFSCORRUPTED;
+ }
+
+ if (S_ISDIR(VFS_I(rp->sc->ip)->i_mode))
+ return xrep_parent_reset_dotdot(rp);
+
+ return 0;
+}
+
+/* Count the number of parent pointers. */
+STATIC int
+xrep_parent_count_pptr(
+ struct xfs_scrub *sc,
+ struct xfs_inode *ip,
+ unsigned int attr_flags,
+ const unsigned char *name,
+ unsigned int namelen,
+ const void *value,
+ unsigned int valuelen,
+ void *priv)
+{
+ struct xrep_parent *rp = priv;
+ int error;
+
+ if (!(attr_flags & XFS_ATTR_PARENT))
+ return 0;
+
+ error = xfs_parent_from_attr(sc->mp, attr_flags, name, namelen, value,
+ valuelen, NULL, NULL);
+ if (error)
+ return error;
+
+ rp->parents++;
+ return 0;
+}
+
+/*
+ * After all parent pointer rebuilding and adoption activity completes, reset
+ * the link count of this nondirectory, having scanned the fs to rebuild all
+ * parent pointers.
+ */
+STATIC int
+xrep_parent_set_nondir_nlink(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ struct xfs_inode *ip = sc->ip;
+ struct xfs_perag *pag;
+ bool joined = false;
+ int error;
+
+ /* Count parent pointers so we can reset the file link count. */
+ rp->parents = 0;
+ error = xchk_xattr_walk(sc, ip, xrep_parent_count_pptr, NULL, rp);
+ if (error)
+ return error;
+
+ if (rp->parents > 0 && xfs_inode_on_unlinked_list(ip)) {
+ xfs_trans_ijoin(sc->tp, sc->ip, 0);
+ joined = true;
+
+ /*
+ * The file is on the unlinked list but we found parents.
+ * Remove the file from the unlinked list.
+ */
+ pag = xfs_perag_get(sc->mp, XFS_INO_TO_AGNO(sc->mp, ip->i_ino));
+ if (!pag) {
+ ASSERT(0);
+ return -EFSCORRUPTED;
+ }
+
+ error = xfs_iunlink_remove(sc->tp, pag, ip);
+ xfs_perag_put(pag);
+ if (error)
+ return error;
+ } else if (rp->parents == 0 && !xfs_inode_on_unlinked_list(ip)) {
+ xfs_trans_ijoin(sc->tp, sc->ip, 0);
+ joined = true;
+
+ /*
+ * The file is not on the unlinked list but we found no
+ * parents. Add the file to the unlinked list.
+ */
+ error = xfs_iunlink(sc->tp, ip);
+ if (error)
+ return error;
+ }
+
+ /* Set the correct link count. */
+ if (VFS_I(ip)->i_nlink != rp->parents) {
+ if (!joined) {
+ xfs_trans_ijoin(sc->tp, sc->ip, 0);
+ joined = true;
+ }
+
+ set_nlink(VFS_I(ip), min_t(unsigned long long, rp->parents,
+ XFS_NLINK_PINNED));
+ }
+
+ /* Log the inode to keep it moving forward if we dirtied anything. */
+ if (joined)
+ xfs_trans_log_inode(sc->tp, ip, XFS_ILOG_CORE);
+ return 0;
+}
+
+/* Set up the filesystem scan so we can look for parents. */
+STATIC int
+xrep_parent_setup_scan(
+ struct xrep_parent *rp)
+{
+ struct xfs_scrub *sc = rp->sc;
+ char *descr;
+ struct xfs_da_geometry *geo = sc->mp->m_attr_geo;
+ int max_len;
+ int error;
+
+ if (!xfs_has_parent(sc->mp))
+ return xrep_findparent_scan_start(sc, &rp->pscan);
+
+ /* Buffers for copying non-pptr attrs to the tempfile */
+ rp->xattr_name = kvmalloc(XATTR_NAME_MAX + 1, XCHK_GFP_FLAGS);
+ if (!rp->xattr_name)
+ return -ENOMEM;
+
+ /*
+ * Allocate enough memory to handle loading local attr values from the
+ * xfblob data while flushing stashed attrs to the temporary file.
+ * We only realloc the buffer when salvaging remote attr values, so
+ * TRY_HARDER means we allocate the maximal attr value size.
+ */
+ if (sc->flags & XCHK_TRY_HARDER)
+ max_len = XATTR_SIZE_MAX;
+ else
+ max_len = xfs_attr_leaf_entsize_local_max(geo->blksize);
+ error = xrep_parent_alloc_xattr_value(rp, max_len);
+ if (error)
+ goto out_xattr_name;
+
+ /* Set up some staging memory for logging parent pointer updates. */
+ descr = xchk_xfile_ino_descr(sc, "parent pointer entries");
+ error = xfarray_create(descr, 0, sizeof(struct xrep_pptr),
+ &rp->pptr_recs);
+ kfree(descr);
+ if (error)
+ goto out_xattr_value;
+
+ descr = xchk_xfile_ino_descr(sc, "parent pointer names");
+ error = xfblob_create(descr, &rp->pptr_names);
+ kfree(descr);
+ if (error)
+ goto out_recs;
+
+ /* Set up some storage for copying attrs before the mapping exchange */
+ descr = xchk_xfile_ino_descr(sc,
+ "parent pointer retained xattr entries");
+ error = xfarray_create(descr, 0, sizeof(struct xrep_parent_xattr),
+ &rp->xattr_records);
+ kfree(descr);
+ if (error)
+ goto out_names;
+
+ descr = xchk_xfile_ino_descr(sc,
+ "parent pointer retained xattr values");
+ error = xfblob_create(descr, &rp->xattr_blobs);
+ kfree(descr);
+ if (error)
+ goto out_attr_keys;
+
+ error = __xrep_findparent_scan_start(sc, &rp->pscan,
+ xrep_parent_live_update);
+ if (error)
+ goto out_attr_values;
+
+ return 0;
+
+out_attr_values:
+ xfblob_destroy(rp->xattr_blobs);
+ rp->xattr_blobs = NULL;
+out_attr_keys:
+ xfarray_destroy(rp->xattr_records);
+ rp->xattr_records = NULL;
+out_names:
+ xfblob_destroy(rp->pptr_names);
+ rp->pptr_names = NULL;
+out_recs:
+ xfarray_destroy(rp->pptr_recs);
+ rp->pptr_recs = NULL;
+out_xattr_value:
+ kvfree(rp->xattr_value);
+ rp->xattr_value = NULL;
+out_xattr_name:
+ kvfree(rp->xattr_name);
+ rp->xattr_name = NULL;
+ return error;
+}
+
+int
+xrep_parent(
+ struct xfs_scrub *sc)
+{
+ struct xrep_parent *rp = sc->buf;
+ int error;
+
+ /*
+ * When the parent pointers feature is enabled, repairs are committed
+ * by atomically committing a new xattr structure and reaping the old
+ * attr fork. Reaping requires rmap and exchange-range to be enabled.
+ */
+ if (xfs_has_parent(sc->mp)) {
+ if (!xfs_has_rmapbt(sc->mp))
+ return -EOPNOTSUPP;
+ if (!xfs_has_exchange_range(sc->mp))
+ return -EOPNOTSUPP;
+ }
+
+ error = xrep_parent_setup_scan(rp);
+ if (error)
+ return error;
+
+ if (xfs_has_parent(sc->mp))
+ error = xrep_parent_scan_dirtree(rp);
+ else
+ error = xrep_parent_find_dotdot(rp);
+ if (error)
+ goto out_teardown;
+
+ /* Last chance to abort before we start committing dotdot fixes. */
+ if (xchk_should_terminate(sc, &error))
+ goto out_teardown;
+
+ error = xrep_parent_rebuild_tree(rp);
+ if (error)
+ goto out_teardown;
+ if (xfs_has_parent(sc->mp) && !S_ISDIR(VFS_I(sc->ip)->i_mode)) {
+ error = xrep_parent_set_nondir_nlink(rp);
+ if (error)
+ goto out_teardown;
+ }
+
+ error = xrep_defer_finish(sc);
+
+out_teardown:
+ xrep_parent_teardown(rp);
+ return error;
+}