xfs: create block pointer check functions

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>

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index f965ce832bc0561acb50a67ce28373fc7fb0b091..11c01e2668bf0b2123f3526ebfbfd9923cbca1be 100644 (file)
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2931,3 +2931,52 @@ 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/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h
index ef26edc2e938349b918157d20557fac6ab9d10b0..7ba2d129d50453689b887f8b1bee5686a2c0ccb8 100644 (file)
--- a/fs/xfs/libxfs/xfs_alloc.h
+++ b/fs/xfs/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/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index 5d4e43ef4eea21298ec5c8f3df691abdce1eee0a..4523a92d5507f27b61251698aa119ba0a4975603 100644 (file)
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -1086,3 +1086,15 @@ 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;
+}

diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
index 79defa722bf1c49c775822532e99c508fbd8757e..3f30f846d7f29fee442c02738d124159249d1959 100644 (file)
--- a/fs/xfs/xfs_rtalloc.h
+++ b/fs/xfs/xfs_rtalloc.h
@@ -138,6 +138,7 @@ int xfs_rtalloc_query_range(struct xfs_trans *tp,
 int xfs_rtalloc_query_all(struct xfs_trans *tp,
                          xfs_rtalloc_query_range_fn fn,
                          void *priv);
+bool xfs_verify_rtbno(struct xfs_mount *mp, xfs_rtblock_t rtbno);
 #else
 # define xfs_rtallocate_extent(t,b,min,max,l,f,p,rb)    (ENOSYS)
 # define xfs_rtfree_extent(t,b,l)                       (ENOSYS)
@@ -146,6 +147,7 @@ int xfs_rtalloc_query_all(struct xfs_trans *tp,
 # define xfs_rtalloc_query_range(t,l,h,f,p)             (ENOSYS)
 # define xfs_rtalloc_query_all(t,f,p)                   (ENOSYS)
 # define xfs_rtbuf_get(m,t,b,i,p)                       (ENOSYS)
+# define xfs_verify_rtbno(m, r)                        (false)
 static inline int              /* error */
 xfs_rtmount_init(
        xfs_mount_t     *mp)    /* file system mount structure */