From: Darrick J. Wong <djwong@xxxxxxxxxx>
If we encounter an inode with a nonzero link count but zero observed
links, move it to the orphanage.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
fs/xfs/scrub/nlinks.c | 11 +++-
fs/xfs/scrub/nlinks.h | 6 ++
fs/xfs/scrub/nlinks_repair.c | 129 ++++++++++++++++++++++++++++++++++++++++--
fs/xfs/scrub/repair.h | 2 +
fs/xfs/scrub/trace.c | 1
fs/xfs/scrub/trace.h | 26 ++++++++
6 files changed, 167 insertions(+), 8 deletions(-)
diff --git a/fs/xfs/scrub/nlinks.c b/fs/xfs/scrub/nlinks.c
index 69af584562ed..67e2c167fc36 100644
--- a/fs/xfs/scrub/nlinks.c
+++ b/fs/xfs/scrub/nlinks.c
@@ -24,6 +24,7 @@
#include "scrub/xfile.h"
#include "scrub/xfarray.h"
#include "scrub/iscan.h"
+#include "scrub/orphanage.h"
#include "scrub/nlinks.h"
#include "scrub/trace.h"
#include "scrub/readdir.h"
@@ -44,9 +45,17 @@ int
xchk_setup_nlinks(
struct xfs_scrub *sc)
{
+ int error;
+
xchk_fsgates_enable(sc, XCHK_FSGATES_DIRENTS);
- sc->buf = kzalloc(sizeof(struct xchk_nlink_ctrs), XCHK_GFP_FLAGS);
+ if (xchk_could_repair(sc)) {
+ error = xrep_setup_nlinks(sc);
+ if (error)
+ return error;
+ }
+
+ sc->buf = kvzalloc(sizeof(struct xchk_nlink_ctrs), XCHK_GFP_FLAGS);
if (!sc->buf)
return -ENOMEM;
diff --git a/fs/xfs/scrub/nlinks.h b/fs/xfs/scrub/nlinks.h
index c3c7e79efc3f..0036d62f3d6c 100644
--- a/fs/xfs/scrub/nlinks.h
+++ b/fs/xfs/scrub/nlinks.h
@@ -28,6 +28,12 @@ struct xchk_nlink_ctrs {
* from other writer threads.
*/
struct xfs_dir_hook hooks;
+
+ /* Orphanage reparenting request. */
+ struct xrep_adoption adoption;
+
+ /* Directory entry name, plus the trailing null. */
+ char namebuf[MAXNAMELEN];
};
/*
diff --git a/fs/xfs/scrub/nlinks_repair.c b/fs/xfs/scrub/nlinks_repair.c
index f500f23f7b4f..1666871e3fba 100644
--- a/fs/xfs/scrub/nlinks_repair.c
+++ b/fs/xfs/scrub/nlinks_repair.c
@@ -24,6 +24,7 @@
#include "scrub/xfile.h"
#include "scrub/xfarray.h"
#include "scrub/iscan.h"
+#include "scrub/orphanage.h"
#include "scrub/nlinks.h"
#include "scrub/trace.h"
#include "scrub/tempfile.h"
@@ -38,6 +39,59 @@
* inode is locked.
*/
+/* Set up to repair inode link counts. */
+int
+xrep_setup_nlinks(
+ struct xfs_scrub *sc)
+{
+ return xrep_orphanage_try_create(sc);
+}
+
+/*
+ * Inodes that aren't the root directory or the orphanage, have a nonzero link
+ * count, and no observed parents should be moved to the orphanage.
+ */
+static inline bool
+xrep_nlinks_is_orphaned(
+ struct xfs_scrub *sc,
+ struct xfs_inode *ip,
+ unsigned int actual_nlink,
+ const struct xchk_nlink *obs)
+{
+ struct xfs_mount *mp = ip->i_mount;
+
+ if (obs->parents != 0)
+ return false;
+ if (ip == mp->m_rootip || ip == sc->orphanage)
+ return false;
+ return actual_nlink != 0;
+}
+
+/*
+ * Reattach this file to the directory tree by moving it to /lost+found per the
+ * adoption parameters that we already computed. Returns 0 for success,
+ * -EMLINK if we cannot complete the adoption because doing so would cause a
+ * link count overflow, or the usual negative errno.
+ */
+STATIC int
+xrep_nlinks_adopt(
+ struct xchk_nlink_ctrs *xnc)
+{
+ int error;
+
+ /* Figure out what name we're going to use here. */
+ error = xrep_adoption_compute_name(&xnc->adoption, xnc->namebuf);
+ if (error)
+ return error;
+
+ /*
+ * Create the new name in the orphanage, and bump the link
+ * count of the orphanage if we just added a directory. Then
+ * we can set the correct nlink.
+ */
+ return xrep_adoption_commit(&xnc->adoption);
+}
+
/* Remove an inode from the unlinked list. */
STATIC int
xrep_nlinks_iunlink_remove(
@@ -66,6 +120,8 @@ xrep_nlinks_repair_inode(
struct xfs_inode *ip = sc->ip;
uint64_t total_links;
uint64_t actual_nlink;
+ bool orphanage_available = false;
+ bool adoption_performed = false;
bool dirty = false;
int error;
@@ -77,14 +133,38 @@ xrep_nlinks_repair_inode(
if (xrep_is_tempfile(ip))
return 0;
- xchk_ilock(sc, XFS_IOLOCK_EXCL);
+ if (sc->orphanage && sc->ip != sc->orphanage) {
+ /*
+ * Allocate a transaction for the adoption. We'll reserve
+ * space for the transaction in the adoption preparation step.
+ */
+ error = xrep_adoption_init(sc, &xnc->adoption);
+ if (!error) {
+ orphanage_available = true;
+
+ /* Take IOLOCK of the orphanage and the child. */
+ error = xrep_orphanage_iolock_two(sc);
+ if (error)
+ return error;
+ }
+ }
+ if (!orphanage_available)
+ xchk_ilock(sc, XFS_IOLOCK_EXCL);
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, 0, 0, 0, &sc->tp);
if (error)
goto out_iolock;
- xchk_ilock(sc, XFS_ILOCK_EXCL);
- xfs_trans_ijoin(sc->tp, ip, 0);
+ if (orphanage_available) {
+ error = xrep_adoption_prep(&xnc->adoption);
+ if (error) {
+ xchk_trans_cancel(sc);
+ goto out_iolock;
+ }
+ } else {
+ xchk_ilock(sc, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(sc->tp, ip, 0);
+ }
mutex_lock(&xnc->lock);
@@ -122,6 +202,29 @@ xrep_nlinks_repair_inode(
goto out_trans;
}
+ /*
+ * Decide if we're going to move this file to the orphanage, and fix
+ * up the incore link counts if we are.
+ */
+ if (orphanage_available &&
+ xrep_nlinks_is_orphaned(sc, ip, actual_nlink, &obs)) {
+ error = xrep_nlinks_adopt(xnc);
+ if (error)
+ goto out_trans;
+ adoption_performed = true;
+
+ /* Re-read the link counts. */
+ mutex_lock(&xnc->lock);
+ error = xfarray_load_sparse(xnc->nlinks, ip->i_ino, &obs);
+ mutex_unlock(&xnc->lock);
+ if (error)
+ goto out_trans;
+
+ total_links = xchk_nlink_total(ip, &obs);
+ actual_nlink = VFS_I(ip)->i_nlink;
+ dirty = true;
+ }
+
/*
* If this inode is linked from the directory tree and on the unlinked
* list, remove it from the unlinked list.
@@ -167,6 +270,11 @@ xrep_nlinks_repair_inode(
goto out_ilock;
xchk_iunlock(sc, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+ if (orphanage_available) {
+ xrep_orphanage_iunlock(sc, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+ if (!adoption_performed)
+ xrep_adoption_cancel(&xnc->adoption, 0);
+ }
return 0;
out_scanlock:
@@ -175,8 +283,15 @@ xrep_nlinks_repair_inode(
xchk_trans_cancel(sc);
out_ilock:
xchk_iunlock(sc, XFS_ILOCK_EXCL);
+ if (orphanage_available && (sc->orphanage_ilock_flags & XFS_ILOCK_EXCL))
+ xrep_orphanage_iunlock(sc, XFS_ILOCK_EXCL);
out_iolock:
xchk_iunlock(sc, XFS_IOLOCK_EXCL);
+ if (orphanage_available) {
+ xrep_orphanage_iunlock(sc, XFS_IOLOCK_EXCL);
+ if (!adoption_performed)
+ xrep_adoption_cancel(&xnc->adoption, error);
+ }
return error;
}
@@ -209,10 +324,10 @@ xrep_nlinks(
/*
* We need ftype for an accurate count of the number of child
* subdirectory links. Child subdirectories with a back link (dotdot
- * entry) but no forward link are unfixable, so we cannot repair the
- * link count of the parent directory based on the back link count
- * alone. Filesystems without ftype support are rare (old V4) so we
- * just skip out here.
+ * entry) but no forward link are moved to the orphanage, so we cannot
+ * repair the link count of the parent directory based on the back link
+ * count alone. Filesystems without ftype support are rare (old V4) so
+ * we just skip out here.
*/
if (!xfs_has_ftype(sc->mp))
return -EOPNOTSUPP;
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index d845997ed60b..0798e580589e 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -86,6 +86,7 @@ int xrep_setup_rtsummary(struct xfs_scrub *sc, unsigned int *resblks,
int xrep_setup_xattr(struct xfs_scrub *sc);
int xrep_setup_directory(struct xfs_scrub *sc);
int xrep_setup_parent(struct xfs_scrub *sc);
+int xrep_setup_nlinks(struct xfs_scrub *sc);
/* Repair setup functions */
int xrep_setup_ag_allocbt(struct xfs_scrub *sc);
@@ -195,6 +196,7 @@ xrep_setup_nothing(
#define xrep_setup_xattr xrep_setup_nothing
#define xrep_setup_directory xrep_setup_nothing
#define xrep_setup_parent xrep_setup_nothing
+#define xrep_setup_nlinks xrep_setup_nothing
#define xrep_setup_inode(sc, imap) ((void)0)
diff --git a/fs/xfs/scrub/trace.c b/fs/xfs/scrub/trace.c
index e7672264714c..18a1a3d1cbef 100644
--- a/fs/xfs/scrub/trace.c
+++ b/fs/xfs/scrub/trace.c
@@ -22,6 +22,7 @@
#include "scrub/xfile.h"
#include "scrub/xfarray.h"
#include "scrub/iscan.h"
+#include "scrub/orphanage.h"
#include "scrub/nlinks.h"
#include "scrub/fscounters.h"
#include "scrub/xfbtree.h"
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index abf8d1fad537..cbac347b4a79 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -2567,6 +2567,32 @@ DEFINE_XREP_PARENT_SALVAGE_CLASS(xrep_dir_salvaged_parent);
DEFINE_XREP_PARENT_SALVAGE_CLASS(xrep_findparent_dirent);
DEFINE_XREP_PARENT_SALVAGE_CLASS(xrep_findparent_from_dcache);
+TRACE_EVENT(xrep_nlinks_set_record,
+ TP_PROTO(struct xfs_mount *mp, xfs_ino_t ino,
+ const struct xchk_nlink *obs),
+ TP_ARGS(mp, ino, obs),
+ 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 = obs->parents;
+ __entry->backrefs = obs->backrefs;
+ __entry->children = obs->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)
+);
+
#endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
