[PATCH 13/27] xfs: scrub the AGI

Darrick J. Wong
2017-09-21T00:18:58Z

Add a forgotten check to the AGI verifier, then wire up the scrub
infrastructure to check the AGI contents.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_fs.h | 3 +-
fs/xfs/scrub/agheader.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/common.c | 6 ++-
fs/xfs/scrub/scrub.c | 4 ++
fs/xfs/scrub/scrub.h | 1 +
5 files changed, 99 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index a22d90f..2ac0049 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -487,9 +487,10 @@ struct xfs_scrub_metadata {
#define XFS_SCRUB_TYPE_SB 1 /* superblock */
#define XFS_SCRUB_TYPE_AGF 2 /* AG free header */
#define XFS_SCRUB_TYPE_AGFL 3 /* AG free list */
+#define XFS_SCRUB_TYPE_AGI 4 /* AG inode header */

/* Number of scrub subcommands. */
-#define XFS_SCRUB_TYPE_NR 4
+#define XFS_SCRUB_TYPE_NR 5

/* i: Repair this metadata. */
#define XFS_SCRUB_IFLAG_REPAIR (1 << 0)
diff --git a/fs/xfs/scrub/agheader.c b/fs/xfs/scrub/agheader.c
index c2cc2af..cfbbe9e 100644
--- a/fs/xfs/scrub/agheader.c
+++ b/fs/xfs/scrub/agheader.c
@@ -544,3 +544,91 @@ xfs_scrub_agfl(
out:
return error;
}
+
+/* AGI */
+
+/* Scrub the AGI. */
+int
+xfs_scrub_agi(
+ struct xfs_scrub_context *sc)
+{
+ struct xfs_mount *mp = sc->mp;
+ struct xfs_agi *agi;
+ xfs_daddr_t daddr;
+ xfs_daddr_t eofs;
+ xfs_agnumber_t agno;
+ xfs_agblock_t agbno;
+ xfs_agblock_t eoag;
+ xfs_agino_t agino;
+ xfs_agino_t first_agino;
+ xfs_agino_t last_agino;
+ int i;
+ int level;
+ int error = 0;
+
+ agno = sc->sm->sm_agno;
+ error = xfs_scrub_load_ag_headers(sc, agno, XFS_SCRUB_TYPE_AGI);
+ if (!xfs_scrub_op_ok(sc, agno, XFS_AGI_BLOCK(sc->mp), &error))
+ goto out;
+
+ agi = XFS_BUF_TO_AGI(sc->sa.agi_bp);
+ eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
+
+ /* Check the AG length */
+ eoag = be32_to_cpu(agi->agi_length);
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp,
+ eoag == xfs_scrub_ag_blocks(mp, agno));
+
+ /* Check btree roots and levels */
+ agbno = be32_to_cpu(agi->agi_root);
+ daddr = XFS_AGB_TO_DADDR(mp, agno, agbno);
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp,
+ agbno > XFS_AGI_BLOCK(mp) &&
+ agbno < mp->m_sb.sb_agblocks &&
+ agbno < eoag && daddr < eofs);
+
+ level = be32_to_cpu(agi->agi_level);
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp,
+ level > 0 && level <= XFS_BTREE_MAXLEVELS);
+
+ if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
+ agbno = be32_to_cpu(agi->agi_free_root);
+ daddr = XFS_AGB_TO_DADDR(mp, agno, agbno);
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp,
+ agbno > XFS_AGI_BLOCK(mp) &&
+ agbno < mp->m_sb.sb_agblocks &&
+ agbno < eoag && daddr < eofs);
+
+ level = be32_to_cpu(agi->agi_free_level);
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp,
+ level > 0 && level <= XFS_BTREE_MAXLEVELS);
+ }
+
+ /* Check inode counters */
+ first_agino = XFS_OFFBNO_TO_AGINO(mp, XFS_AGI_BLOCK(mp) + 1, 0);
+ last_agino = XFS_OFFBNO_TO_AGINO(mp, eoag + 1, 0) - 1;
+ agino = be32_to_cpu(agi->agi_count);
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp,
+ agino <= last_agino - first_agino + 1 &&
+ agino >= be32_to_cpu(agi->agi_freecount));
+
+ /* Check inode pointers */
+ agino = be32_to_cpu(agi->agi_newino);
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp, agino == NULLAGINO ||
+ (agino >= first_agino && agino <= last_agino));
+ agino = be32_to_cpu(agi->agi_dirino);
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp, agino == NULLAGINO ||
+ (agino >= first_agino && agino <= last_agino));
+
+ /* Check unlinked inode buckets */
+ for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
+ agino = be32_to_cpu(agi->agi_unlinked[i]);
+ if (agino == NULLAGINO)
+ continue;
+ xfs_scrub_block_check_ok(sc, sc->sa.agi_bp,
+ (agino >= first_agino && agino <= last_agino));
+ }
+
+out:
+ return error;
+}
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index e0e611d..b62f084 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -499,12 +499,14 @@ xfs_scrub_load_ag_headers(
struct xfs_mount *mp = sc->mp;
int error;

- ASSERT(type == XFS_SCRUB_TYPE_AGF || type == XFS_SCRUB_TYPE_AGFL);
+ ASSERT(type == XFS_SCRUB_TYPE_AGF || type == XFS_SCRUB_TYPE_AGFL ||
+ type == XFS_SCRUB_TYPE_AGI);
memset(&sc->sa, 0, sizeof(sc->sa));
sc->sa.agno = agno;

error = xfs_scrub_load_ag_header(sc, XFS_AGI_DADDR(mp),
- &sc->sa.agi_bp, &xfs_agi_buf_ops, false);
+ &sc->sa.agi_bp, &xfs_agi_buf_ops,
+ type == XFS_SCRUB_TYPE_AGI);
if (error)
return error;

diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index 1afce7b..5fc34a6 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -174,6 +174,10 @@ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
.setup = xfs_scrub_setup_ag_header,
.scrub = xfs_scrub_agfl,
},
+ { /* agi */
+ .setup = xfs_scrub_setup_ag_header,
+ .scrub = xfs_scrub_agi,
+ },
};

/* Dispatch metadata scrubbing. */
diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index cb31a01..00020a3 100644
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -65,5 +65,6 @@ int xfs_scrub_tester(struct xfs_scrub_context *sc);
int xfs_scrub_superblock(struct xfs_scrub_context *sc);
int xfs_scrub_agf(struct xfs_scrub_context *sc);
int xfs_scrub_agfl(struct xfs_scrub_context *sc);
+int xfs_scrub_agi(struct xfs_scrub_context *sc);

#endif /* __XFS_SCRUB_SCRUB_H__ */