From: Darrick J. Wong <djwong@xxxxxxxxxx>
Upgrade an existing filesystem to have parent pointers.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
man/man8/xfs_admin.8 | 8 ++++++++
repair/globals.c | 1 +
repair/globals.h | 1 +
repair/phase2.c | 39 +++++++++++++++++++++++++++++++++++++++
repair/pptr.c | 15 ++++++++++++++-
repair/xfs_repair.c | 11 +++++++++++
6 files changed, 74 insertions(+), 1 deletion(-)
diff --git a/man/man8/xfs_admin.8 b/man/man8/xfs_admin.8
index 467fb2dfd0a..28f28b6dd8f 100644
--- a/man/man8/xfs_admin.8
+++ b/man/man8/xfs_admin.8
@@ -177,6 +177,14 @@ and online repairs to space usage metadata.
The filesystem cannot be downgraded after this feature is enabled.
This upgrade can fail if any AG has less than 5% free space remaining.
This feature was added to Linux 4.8.
+.TP 0.4i
+.B parent
+Store in each child file a mirror a pointing back to the parent directory.
+This enables much stronger cross-referencing and online repairs of the
+directory tree.
+The filesystem cannot be downgraded after this feature is enabled.
+This upgrade can fail if the filesystem has less than 25% free space remaining.
+This feature is not upstream yet.
.RE
.TP
.BI \-U " uuid"
diff --git a/repair/globals.c b/repair/globals.c
index cff620e8f0e..7d95e210e8e 100644
--- a/repair/globals.c
+++ b/repair/globals.c
@@ -55,6 +55,7 @@ bool add_nrext64;
bool add_finobt; /* add free inode btrees */
bool add_reflink; /* add reference count btrees */
bool add_rmapbt; /* add reverse mapping btrees */
+bool add_parent; /* add parent pointers */
/* misc status variables */
diff --git a/repair/globals.h b/repair/globals.h
index 76d22fd3b2c..71a64b94365 100644
--- a/repair/globals.h
+++ b/repair/globals.h
@@ -96,6 +96,7 @@ extern bool add_nrext64;
extern bool add_finobt; /* add free inode btrees */
extern bool add_reflink; /* add reference count btrees */
extern bool add_rmapbt; /* add reverse mapping btrees */
+extern bool add_parent; /* add parent pointers */
/* misc status variables */
diff --git a/repair/phase2.c b/repair/phase2.c
index be0d791a8b5..a58fa7d8a7b 100644
--- a/repair/phase2.c
+++ b/repair/phase2.c
@@ -265,6 +265,28 @@ set_rmapbt(
return true;
}
+static bool
+set_parent(
+ struct xfs_mount *mp,
+ struct xfs_sb *new_sb)
+{
+ if (xfs_has_parent(mp)) {
+ printf(_("Filesystem already supports parent pointers.\n"));
+ exit(0);
+ }
+
+ if (!xfs_has_crc(mp)) {
+ printf(
+ _("Parent pointer feature only supported on V5 filesystems.\n"));
+ exit(0);
+ }
+
+ printf(_("Adding parent pointers to filesystem.\n"));
+ new_sb->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_PARENT;
+ new_sb->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR;
+ return true;
+}
+
struct check_state {
struct xfs_sb sb;
uint64_t features;
@@ -406,6 +428,19 @@ check_fs_free_space(
libxfs_trans_cancel(tp);
}
+ /*
+ * If we're adding parent pointers, we need at least 25% free since
+ * scanning the entire filesystem to guesstimate the overhead is
+ * prohibitively expensive.
+ */
+ if (xfs_has_parent(mp) && !(old->features & XFS_FEAT_PARENT)) {
+ if (mp->m_sb.sb_fdblocks < mp->m_sb.sb_dblocks / 4) {
+ printf(
+ _("Filesystem does not have enough space to add parent pointers.\n"));
+ exit(1);
+ }
+ }
+
/*
* Would the post-upgrade filesystem have enough free space on the data
* device after making per-AG reservations?
@@ -438,6 +473,8 @@ need_check_fs_free_space(
return true;
if (xfs_has_rmapbt(mp) && !(old->features & XFS_FEAT_RMAPBT))
return true;
+ if (xfs_has_parent(mp) && !(old->features & XFS_FEAT_PARENT))
+ return true;
return false;
}
@@ -519,6 +556,8 @@ upgrade_filesystem(
dirty |= set_reflink(mp, &new_sb);
if (add_rmapbt)
dirty |= set_rmapbt(mp, &new_sb);
+ if (add_parent)
+ dirty |= set_parent(mp, &new_sb);
if (!dirty)
return;
diff --git a/repair/pptr.c b/repair/pptr.c
index 46a214f205e..77f49dbcb84 100644
--- a/repair/pptr.c
+++ b/repair/pptr.c
@@ -809,7 +809,7 @@ add_missing_parent_ptr(
ag_pptr->namelen,
name);
return;
- } else {
+ } else if (!add_parent) {
do_warn(
_("adding missing ino %llu parent pointer (ino %llu gen 0x%x name '%.*s')\n"),
(unsigned long long)ip->i_ino,
@@ -817,6 +817,19 @@ add_missing_parent_ptr(
ag_pptr->parent_gen,
ag_pptr->namelen,
name);
+ } else {
+ static bool warned = false;
+ static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+
+ if (!warned) {
+ pthread_mutex_lock(&lock);
+ if (!warned) {
+ do_warn(
+ _("setting parent pointers to upgrade filesystem\n"));
+ warned = true;
+ }
+ pthread_mutex_unlock(&lock);
+ }
}
error = add_file_pptr(ip, ag_pptr, name);
diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
index e94b0a79378..32c28a980ff 100644
--- a/repair/xfs_repair.c
+++ b/repair/xfs_repair.c
@@ -72,6 +72,7 @@ enum c_opt_nums {
CONVERT_FINOBT,
CONVERT_REFLINK,
CONVERT_RMAPBT,
+ CONVERT_PARENT,
C_MAX_OPTS,
};
@@ -83,6 +84,7 @@ static char *c_opts[] = {
[CONVERT_FINOBT] = "finobt",
[CONVERT_REFLINK] = "reflink",
[CONVERT_RMAPBT] = "rmapbt",
+ [CONVERT_PARENT] = "parent",
[C_MAX_OPTS] = NULL,
};
@@ -369,6 +371,15 @@ process_args(int argc, char **argv)
_("-c rmapbt only supports upgrades\n"));
add_rmapbt = true;
break;
+ case CONVERT_PARENT:
+ if (!val)
+ do_abort(
+ _("-c parent requires a parameter\n"));
+ if (strtol(val, NULL, 0) != 1)
+ do_abort(
+ _("-c parent only supports upgrades\n"));
+ add_parent = true;
+ break;
default:
unknown('c', val);
break;
