[PATCH 27/37] xfs: online repair of realtime file bmaps

Darrick J. Wong
2024-12-13T01:07:38Z

From: Darrick J. Wong <djwong@kernel.org>

Repair the block mappings of realtime files.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
fs/xfs/scrub/bmap_repair.c | 128 +++++++++++++++++++++++++++++++++++++++++++-
fs/xfs/scrub/repair.c | 46 ++++++++++++++++
fs/xfs/scrub/repair.h | 2 +
3 files changed, 172 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/scrub/bmap_repair.c b/fs/xfs/scrub/bmap_repair.c
index 141d36f1da9a71..fd64bdf4e13887 100644
--- a/fs/xfs/scrub/bmap_repair.c
+++ b/fs/xfs/scrub/bmap_repair.c
@@ -25,11 +25,13 @@
#include "xfs_bmap_btree.h"
#include "xfs_rmap.h"
#include "xfs_rmap_btree.h"
+#include "xfs_rtrmap_btree.h"
#include "xfs_refcount.h"
#include "xfs_quota.h"
#include "xfs_ialloc.h"
#include "xfs_ag.h"
#include "xfs_reflink.h"
+#include "xfs_rtgroup.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
@@ -359,6 +361,112 @@ xrep_bmap_scan_ag(
return error;
}

+#ifdef CONFIG_XFS_RT
+/* Check for any obvious errors or conflicts in the file mapping. */
+STATIC int
+xrep_bmap_check_rtfork_rmap(
+ struct xfs_scrub *sc,
+ struct xfs_btree_cur *cur,
+ const struct xfs_rmap_irec *rec)
+{
+ /* xattr extents are never stored on realtime devices */
+ if (rec->rm_flags & XFS_RMAP_ATTR_FORK)
+ return -EFSCORRUPTED;
+
+ /* bmbt blocks are never stored on realtime devices */
+ if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
+ return -EFSCORRUPTED;
+
+ /* Data extents for non-rt files are never stored on the rt device. */
+ if (!XFS_IS_REALTIME_INODE(sc->ip))
+ return -EFSCORRUPTED;
+
+ /* Check the file offsets and physical extents. */
+ if (!xfs_verify_fileext(sc->mp, rec->rm_offset, rec->rm_blockcount))
+ return -EFSCORRUPTED;
+
+ /* Check that this is within the rtgroup. */
+ if (!xfs_verify_rgbext(to_rtg(cur->bc_group), rec->rm_startblock,
+ rec->rm_blockcount))
+ return -EFSCORRUPTED;
+
+ /* Make sure this isn't free space. */
+ return xrep_require_rtext_inuse(sc, rec->rm_startblock,
+ rec->rm_blockcount);
+}
+
+/* Record realtime extents that belong to this inode's fork. */
+STATIC int
+xrep_bmap_walk_rtrmap(
+ struct xfs_btree_cur *cur,
+ const struct xfs_rmap_irec *rec,
+ void *priv)
+{
+ struct xrep_bmap *rb = priv;
+ int error = 0;
+
+ if (xchk_should_terminate(rb->sc, &error))
+ return error;
+
+ /* Skip extents which are not owned by this inode and fork. */
+ if (rec->rm_owner != rb->sc->ip->i_ino)
+ return 0;
+
+ error = xrep_bmap_check_rtfork_rmap(rb->sc, cur, rec);
+ if (error)
+ return error;
+
+ /*
+ * Record all blocks allocated to this file even if the extent isn't
+ * for the fork we're rebuilding so that we can reset di_nblocks later.
+ */
+ rb->nblocks += rec->rm_blockcount;
+
+ /* If this rmap isn't for the fork we want, we're done. */
+ if (rb->whichfork == XFS_DATA_FORK &&
+ (rec->rm_flags & XFS_RMAP_ATTR_FORK))
+ return 0;
+ if (rb->whichfork == XFS_ATTR_FORK &&
+ !(rec->rm_flags & XFS_RMAP_ATTR_FORK))
+ return 0;
+
+ return xrep_bmap_from_rmap(rb, rec->rm_offset,
+ xfs_rgbno_to_rtb(to_rtg(cur->bc_group),
+ rec->rm_startblock),
+ rec->rm_blockcount,
+ rec->rm_flags & XFS_RMAP_UNWRITTEN);
+}
+
+/* Scan the realtime reverse mappings to build the new extent map. */
+STATIC int
+xrep_bmap_scan_rtgroup(
+ struct xrep_bmap *rb,
+ struct xfs_rtgroup *rtg)
+{
+ struct xfs_scrub *sc = rb->sc;
+ int error;
+
+ if (!xfs_has_rtrmapbt(sc->mp))
+ return 0;
+
+ error = xrep_rtgroup_init(sc, rtg, &sc->sr,
+ XFS_RTGLOCK_RMAP | XFS_RTGLOCK_BITMAP_SHARED);
+ if (error)
+ return error;
+
+ error = xfs_rmap_query_all(sc->sr.rmap_cur, xrep_bmap_walk_rtrmap, rb);
+ xchk_rtgroup_btcur_free(&sc->sr);
+ xchk_rtgroup_free(sc, &sc->sr);
+ return error;
+}
+#else
+static inline int
+xrep_bmap_scan_rtgroup(struct xrep_bmap *rb, struct xfs_rtgroup *rtg)
+{
+ return -EFSCORRUPTED;
+}
+#endif
+
/* Find the delalloc extents from the old incore extent tree. */
STATIC int
xrep_bmap_find_delalloc(
@@ -410,6 +518,22 @@ xrep_bmap_find_mappings(
struct xfs_perag *pag = NULL;
int error = 0;

+ /*
+ * Iterate the rtrmaps for extents. Metadata files never have content
+ * on the realtime device, so there's no need to scan them.
+ */
+ if (!xfs_is_metadir_inode(sc->ip)) {
+ struct xfs_rtgroup *rtg = NULL;
+
+ while ((rtg = xfs_rtgroup_next(sc->mp, rtg))) {
+ error = xrep_bmap_scan_rtgroup(rb, rtg);
+ if (error) {
+ xfs_rtgroup_rele(rtg);
+ return error;
+ }
+ }
+ }
+
/* Iterate the rmaps for extents. */
while ((pag = xfs_perag_next(sc->mp, pag))) {
error = xrep_bmap_scan_ag(rb, pag);
@@ -754,10 +878,6 @@ xrep_bmap_check_inputs(
return -EINVAL;
}

- /* Don't know how to rebuild realtime data forks. */
- if (XFS_IS_REALTIME_INODE(sc->ip))
- return -EOPNOTSUPP;
-
return 0;
}

diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index e788e3032f8e33..18946dd46fa745 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -37,6 +37,9 @@
#include "xfs_da_btree.h"
#include "xfs_attr.h"
#include "xfs_dir2.h"
+#include "xfs_rtrmap_btree.h"
+#include "xfs_rtbitmap.h"
+#include "xfs_rtgroup.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
@@ -955,6 +958,22 @@ xrep_ag_init(
}

#ifdef CONFIG_XFS_RT
+/* Initialize all the btree cursors for a RT repair. */
+static void
+xrep_rtgroup_btcur_init(
+ struct xfs_scrub *sc,
+ struct xchk_rt *sr)
+{
+ struct xfs_mount *mp = sc->mp;
+
+ ASSERT(sr->rtg != NULL);
+
+ if (sc->sm->sm_type != XFS_SCRUB_TYPE_RTRMAPBT &&
+ (sr->rtlock_flags & XFS_RTGLOCK_RMAP) &&
+ xfs_has_rtrmapbt(mp))
+ sr->rmap_cur = xfs_rtrmapbt_init_cursor(sc->tp, sr->rtg);
+}
+
/*
* Given a reference to a rtgroup structure, lock rtgroup btree inodes and
* create btree cursors. Must only be called to repair a regular rt file.
@@ -973,6 +992,33 @@ xrep_rtgroup_init(

/* Grab our own passive reference from the caller's ref. */
sr->rtg = xfs_rtgroup_hold(rtg);
+ xrep_rtgroup_btcur_init(sc, sr);
+ return 0;
+}
+
+/* Ensure that all rt blocks in the given range are not marked free. */
+int
+xrep_require_rtext_inuse(
+ struct xfs_scrub *sc,
+ xfs_rgblock_t rgbno,
+ xfs_filblks_t len)
+{
+ struct xfs_mount *mp = sc->mp;
+ xfs_rtxnum_t startrtx;
+ xfs_rtxnum_t endrtx;
+ bool is_free = false;
+ int error;
+
+ startrtx = xfs_rgbno_to_rtx(mp, rgbno);
+ endrtx = xfs_rgbno_to_rtx(mp, rgbno + len - 1);
+
+ error = xfs_rtalloc_extent_is_free(sc->sr.rtg, sc->tp, startrtx,
+ endrtx - startrtx + 1, &is_free);
+ if (error)
+ return error;
+ if (is_free)
+ return -EFSCORRUPTED;
+
return 0;
}
#endif /* CONFIG_XFS_RT */
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index b649da1a93eb8c..584135042d9aa9 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -110,6 +110,8 @@ int xrep_ag_init(struct xfs_scrub *sc, struct xfs_perag *pag,
#ifdef CONFIG_XFS_RT
int xrep_rtgroup_init(struct xfs_scrub *sc, struct xfs_rtgroup *rtg,
struct xchk_rt *sr, unsigned int rtglock_flags);
+int xrep_require_rtext_inuse(struct xfs_scrub *sc, xfs_rgblock_t rgbno,
+ xfs_filblks_t len);
#else
# define xrep_rtgroup_init(sc, rtg, sr, lockflags) (-ENOSYS)
#endif /* CONFIG_XFS_RT */