From: Darrick J. Wong <djwong@xxxxxxxxxx>
When we're walking directories during phase 6, build an index of parent
pointers that we expect to find.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
repair/Makefile | 2 +
repair/phase6.c | 35 +++++++++
repair/pptr.c | 215 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
repair/pptr.h | 15 ++++
4 files changed, 267 insertions(+)
create mode 100644 repair/pptr.c
create mode 100644 repair/pptr.h
diff --git a/repair/Makefile b/repair/Makefile
index d948588781de..b0acc8c46a33 100644
--- a/repair/Makefile
+++ b/repair/Makefile
@@ -24,6 +24,7 @@ HFILES = \
err_protos.h \
globals.h \
incore.h \
+ pptr.h \
prefetch.h \
progress.h \
protos.h \
@@ -63,6 +64,7 @@ CFILES = \
phase5.c \
phase6.c \
phase7.c \
+ pptr.c \
prefetch.c \
progress.c \
quotacheck.c \
diff --git a/repair/phase6.c b/repair/phase6.c
index 9d41aad784a1..fe56feb6ecef 100644
--- a/repair/phase6.c
+++ b/repair/phase6.c
@@ -18,6 +18,7 @@
#include "dinode.h"
#include "progress.h"
#include "versions.h"
+#include "repair/pptr.h"
static struct cred zerocr;
static struct fsxattr zerofsx;
@@ -999,6 +1000,7 @@ mk_orphanage(xfs_mount_t *mp)
do_error(
_("can't make %s, createname error %d\n"),
ORPHANAGE, error);
+ add_parent_ptr(ip->i_ino, (unsigned char *)ORPHANAGE, pip, false);
if (ppargs) {
error = -libxfs_parent_addname(tp, ppargs, pip, &xname, ip);
@@ -1255,6 +1257,10 @@ mv_orphanage(
do_error(
_("orphanage name create failed (%d)\n"), err);
}
+
+ if (xfs_has_parent(mp))
+ add_parent_ptr(ino_p->i_ino, xname.name, orphanage_ip, false);
+
libxfs_irele(ino_p);
libxfs_irele(orphanage_ip);
libxfs_parent_finish(mp, ppargs);
@@ -2894,6 +2900,30 @@ _("entry \"%s\" (ino %" PRIu64 ") in dir %" PRIu64 " already points to ino %" PR
}
}
+static void
+dir_hash_add_parent_ptrs(
+ struct xfs_inode *dp,
+ struct dir_hash_tab *hashtab)
+{
+ struct dir_hash_ent *p;
+
+ if (!xfs_has_parent(dp->i_mount))
+ return;
+
+ for (p = hashtab->first; p; p = p->nextbyorder) {
+ if (p->junkit)
+ continue;
+ if (p->name.name[0] == '/')
+ continue;
+ if (p->name.name[0] == '.' &&
+ (p->name.len == 1 ||
+ (p->name.len == 2 && p->name.name[1] == '.')))
+ continue;
+
+ add_parent_ptr(p->inum, p->name.name, dp, dotdot_update);
+ }
+}
+
/*
* processes all reachable inodes in directories
*/
@@ -3020,6 +3050,7 @@ _("error %d fixing shortform directory %llu\n"),
default:
break;
}
+ dir_hash_add_parent_ptrs(ip, hashtab);
dir_hash_done(hashtab);
/*
@@ -3311,6 +3342,8 @@ phase6(xfs_mount_t *mp)
ino_tree_node_t *irec;
int i;
+ parent_ptr_init(mp);
+
memset(&zerocr, 0, sizeof(struct cred));
memset(&zerofsx, 0, sizeof(struct fsxattr));
orphanage_ino = 0;
@@ -3411,4 +3444,6 @@ _(" - resetting contents of realtime bitmap and summary inodes\n"));
irec = next_ino_rec(irec);
}
}
+
+ parent_ptr_free(mp);
}
diff --git a/repair/pptr.c b/repair/pptr.c
new file mode 100644
index 000000000000..193daa0a5467
--- /dev/null
+++ b/repair/pptr.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@xxxxxxxxxx>
+ */
+#include "libxfs.h"
+#include "libxfs/xfile.h"
+#include "libxfs/xfblob.h"
+#include "libfrog/platform.h"
+#include "repair/err_protos.h"
+#include "repair/slab.h"
+#include "repair/pptr.h"
+
+#undef PPTR_DEBUG
+
+#ifdef PPTR_DEBUG
+# define dbg_printf(f, a...) do {printf(f, ## a); fflush(stdout); } while (0)
+#else
+# define dbg_printf(f, a...)
+#endif
+
+/*
+ * Parent Pointer Validation
+ * =========================
+ *
+ * Phase 6 validates the connectivity of the directory tree after validating
+ * that all the space metadata are correct, and confirming all the inodes that
+ * we intend to keep. The first part of phase 6 walks the directories of the
+ * filesystem to ensure that every file that isn't the root directory has a
+ * parent. Unconnected files are attached to the orphanage. Filesystems with
+ * the directory parent pointer feature enabled must also ensure that for every
+ * directory entry that points to a child file, that child has a matching
+ * parent pointer.
+ *
+ * There are many ways that we could check the parent pointers, but the means
+ * that we have chosen is to build a per-AG master index of all parent pointers
+ * of all inodes stored in that AG, and use that as the basis for comparison.
+ * This consumes a lot of memory, but performing both a forward scan to check
+ * dirent -> parent pointer and a backwards scan of parent pointer -> dirent
+ * takes longer than the simple method presented here. Userspace adds the
+ * additional twist that inodes are not cached (and there are no ILOCKs), which
+ * makes that approach even less attractive.
+ *
+ * During the directory walk at the start of phase 6, we transform each child
+ * directory entry found into its parent pointer equivalent. In other words,
+ * the forward information:
+ *
+ * (dir_ino, name, child_ino)
+ *
+ * becomes this backwards information:
+ *
+ * (child_agino*, dir_ino*, dir_gen, name*)
+ *
+ * Key fields are starred.
+ *
+ * This tuple is recorded in the per-AG master parent pointer index. Note
+ * that names are stored separately in an xfblob data structure so that the
+ * rest of the information can be sorted and processed as fixed-size records;
+ * the incore parent pointer record contains a pointer to the xfblob data.
+ */
+
+struct ag_pptr {
+ /* parent directory handle */
+ xfs_ino_t parent_ino;
+ uint32_t parent_gen;
+
+ /* dirent name length */
+ unsigned short namelen;
+
+ /* AG_PPTR_* flags */
+ unsigned short flags;
+
+ /* cookie for the actual dirent name */
+ xfblob_cookie name_cookie;
+
+ /* agino of the child file */
+ xfs_agino_t child_agino;
+
+ /* hash of the dirent name */
+ xfs_dahash_t namehash;
+};
+
+/* This might be a duplicate due to dotdot reprocessing */
+#define AG_PPTR_POSSIBLE_DUP (1U << 0)
+
+struct ag_pptrs {
+ /* Lock to protect pptr_recs during the dirent scan. */
+ pthread_mutex_t lock;
+
+ /* Parent pointer records for files in this AG. */
+ struct xfs_slab *pptr_recs;
+};
+
+/* Global names storage file. */
+static struct xfblob *names;
+static pthread_mutex_t names_mutex = PTHREAD_MUTEX_INITIALIZER;
+static struct ag_pptrs *fs_pptrs;
+
+void
+parent_ptr_free(
+ struct xfs_mount *mp)
+{
+ xfs_agnumber_t agno;
+
+ if (!xfs_has_parent(mp))
+ return;
+
+ for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
+ free_slab(&fs_pptrs[agno].pptr_recs);
+ pthread_mutex_destroy(&fs_pptrs[agno].lock);
+ }
+ free(fs_pptrs);
+ fs_pptrs = NULL;
+
+ xfblob_destroy(names);
+}
+
+void
+parent_ptr_init(
+ struct xfs_mount *mp)
+{
+ char *descr;
+ xfs_agnumber_t agno;
+ int error;
+
+ if (!xfs_has_parent(mp))
+ return;
+
+ descr = kasprintf(GFP_KERNEL, "xfs_repair (%s): parent pointer names",
+ mp->m_fsname);
+ error = -xfblob_create(descr, &names);
+ kfree(descr);
+ if (error)
+ do_error(_("init parent pointer names failed: %s\n"),
+ strerror(error));
+
+ fs_pptrs = calloc(mp->m_sb.sb_agcount, sizeof(struct ag_pptrs));
+ if (!fs_pptrs)
+ do_error(
+ _("init parent pointer per-AG record array failed: %s\n"),
+ strerror(errno));
+
+ for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
+ error = pthread_mutex_init(&fs_pptrs[agno].lock, NULL);
+ if (error)
+ do_error(
+ _("init agno %u parent pointer lock failed: %s\n"),
+ agno, strerror(error));
+
+ error = -init_slab(&fs_pptrs[agno].pptr_recs,
+ sizeof(struct ag_pptr));
+ if (error)
+ do_error(
+ _("init agno %u parent pointer recs failed: %s\n"),
+ agno, strerror(error));
+ }
+}
+
+/* Remember that @dp has a dirent (@fname, @ino). */
+void
+add_parent_ptr(
+ xfs_ino_t ino,
+ const unsigned char *fname,
+ struct xfs_inode *dp,
+ bool possible_dup)
+{
+ struct xfs_mount *mp = dp->i_mount;
+ struct xfs_name dname = {
+ .name = fname,
+ .len = strlen((char *)fname),
+ };
+ struct ag_pptr ag_pptr = {
+ .child_agino = XFS_INO_TO_AGINO(mp, ino),
+ .parent_ino = dp->i_ino,
+ .parent_gen = VFS_I(dp)->i_generation,
+ .namelen = dname.len,
+ };
+ struct ag_pptrs *ag_pptrs;
+ xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ino);
+ int error;
+
+ if (!xfs_has_parent(mp))
+ return;
+
+ if (possible_dup)
+ ag_pptr.flags |= AG_PPTR_POSSIBLE_DUP;
+
+ ag_pptr.namehash = libxfs_dir2_hashname(mp, &dname);
+
+ pthread_mutex_lock(&names_mutex);
+ error = -xfblob_store(names, &ag_pptr.name_cookie, fname,
+ ag_pptr.namelen);
+ pthread_mutex_unlock(&names_mutex);
+ if (error)
+ do_error(_("storing name '%s' failed: %s\n"),
+ fname, strerror(error));
+
+ ag_pptrs = &fs_pptrs[agno];
+ pthread_mutex_lock(&ag_pptrs->lock);
+ error = -slab_add(ag_pptrs->pptr_recs, &ag_pptr);
+ pthread_mutex_unlock(&ag_pptrs->lock);
+ if (error)
+ do_error(_("storing name '%s' key failed: %s\n"),
+ fname, strerror(error));
+
+ dbg_printf(
+ _("%s: dp %llu gen 0x%x fname '%s' namehash 0x%x ino %llu namecookie 0x%llx\n"),
+ __func__,
+ (unsigned long long)dp->i_ino,
+ VFS_I(dp)->i_generation,
+ fname,
+ ag_pptr.namehash,
+ (unsigned long long)ino,
+ (unsigned long long)ag_pptr.name_cookie);
+}
diff --git a/repair/pptr.h b/repair/pptr.h
new file mode 100644
index 000000000000..7522379423ff
--- /dev/null
+++ b/repair/pptr.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2023-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@xxxxxxxxxx>
+ */
+#ifndef __REPAIR_PPTR_H__
+#define __REPAIR_PPTR_H__
+
+void parent_ptr_free(struct xfs_mount *mp);
+void parent_ptr_init(struct xfs_mount *mp);
+
+void add_parent_ptr(xfs_ino_t ino, const unsigned char *fname,
+ struct xfs_inode *dp, bool possible_dup);
+
+#endif /* __REPAIR_PPTR_H__ */
