xfs: create block pointer check functions

Source kernel commit: 21ec54168b368f1a98097dee00625ec8ec2d47f3

Create some helper functions to check that a block pointer points
within the filesystem (or AG) and doesn't point at static metadata.
We will use this for scrub.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c
index 4bd11d3d350e8ddeba54f8adb30f68163f2ce0ea..31058ab2f9fc90ee326254f7f8c94da98f86bf56 100644 (file)
--- a/libxfs/xfs_alloc.c
+++ b/libxfs/xfs_alloc.c
@@ -2928,3 +2928,52 @@ xfs_alloc_query_all(
        query.fn = fn;
        return xfs_btree_query_all(cur, xfs_alloc_query_range_helper, &query);
 }
+
+/* Find the size of the AG, in blocks. */
+xfs_agblock_t
+xfs_ag_block_count(
+       struct xfs_mount        *mp,
+       xfs_agnumber_t          agno)
+{
+       ASSERT(agno < mp->m_sb.sb_agcount);
+
+       if (agno < mp->m_sb.sb_agcount - 1)
+               return mp->m_sb.sb_agblocks;
+       return mp->m_sb.sb_dblocks - (agno * mp->m_sb.sb_agblocks);
+}
+
+/*
+ * Verify that an AG block number pointer neither points outside the AG
+ * nor points at static metadata.
+ */
+bool
+xfs_verify_agbno(
+       struct xfs_mount        *mp,
+       xfs_agnumber_t          agno,
+       xfs_agblock_t           agbno)
+{
+       xfs_agblock_t           eoag;
+
+       eoag = xfs_ag_block_count(mp, agno);
+       if (agbno >= eoag)
+               return false;
+       if (agbno <= XFS_AGFL_BLOCK(mp))
+               return false;
+       return true;
+}
+
+/*
+ * Verify that an FS block number pointer neither points outside the
+ * filesystem nor points at static AG metadata.
+ */
+bool
+xfs_verify_fsbno(
+       struct xfs_mount        *mp,
+       xfs_fsblock_t           fsbno)
+{
+       xfs_agnumber_t          agno = XFS_FSB_TO_AGNO(mp, fsbno);
+
+       if (agno >= mp->m_sb.sb_agcount)
+               return false;
+       return xfs_verify_agbno(mp, agno, XFS_FSB_TO_AGBNO(mp, fsbno));
+}

diff --git a/libxfs/xfs_alloc.h b/libxfs/xfs_alloc.h
index ef26edc2e938349b918157d20557fac6ab9d10b0..7ba2d129d50453689b887f8b1bee5686a2c0ccb8 100644 (file)
--- a/libxfs/xfs_alloc.h
+++ b/libxfs/xfs_alloc.h
@@ -232,5 +232,9 @@ int xfs_alloc_query_range(struct xfs_btree_cur *cur,
                xfs_alloc_query_range_fn fn, void *priv);
 int xfs_alloc_query_all(struct xfs_btree_cur *cur, xfs_alloc_query_range_fn fn,
                void *priv);
+xfs_agblock_t xfs_ag_block_count(struct xfs_mount *mp, xfs_agnumber_t agno);
+bool xfs_verify_agbno(struct xfs_mount *mp, xfs_agnumber_t agno,
+               xfs_agblock_t agbno);
+bool xfs_verify_fsbno(struct xfs_mount *mp, xfs_fsblock_t fsbno);
 
 #endif /* __XFS_ALLOC_H__ */

diff --git a/libxfs/xfs_rtbitmap.c b/libxfs/xfs_rtbitmap.c
index 453dbb9ae38a90a25ad6e1056411ccbb5a28e929..8da151b7dbb3a2f1add2fec580dae07bc2c05154 100644 (file)
--- a/libxfs/xfs_rtbitmap.c
+++ b/libxfs/xfs_rtbitmap.c
@@ -1081,3 +1081,15 @@ xfs_rtalloc_query_all(
 
        return xfs_rtalloc_query_range(tp, &keys[0], &keys[1], fn, priv);
 }
+
+/*
+ * Verify that an realtime block number pointer doesn't point off the
+ * end of the realtime device.
+ */
+bool
+xfs_verify_rtbno(
+       struct xfs_mount        *mp,
+       xfs_rtblock_t           rtbno)
+{
+       return rtbno < mp->m_sb.sb_rblocks;
+}