[XFS] refactor btree validation helpers

Move the various btree validation helpers around in xfs_btree.c so that
they are close to each other and in common #ifdef DEBUG sections.

Also add a new xfs_btree_check_ptr helper to check a btree ptr that can be
either long or short form.

Split out from a bigger patch from Dave Chinner with various small changes
applied by me.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32183a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>

2 files changed, 155 insertions, 138 deletions

diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
index 4d793e4ccdcc..966d58d50fad 100644
--- a/fs/xfs/xfs_btree.c
+++ b/fs/xfs/xfs_btree.c
@@ -81,24 +81,6 @@ xfs_btree_maxrecs(
 
 #ifdef DEBUG
 /*
- * Debug routine: check that block header is ok.
- */
-void
-xfs_btree_check_block(
-        xfs_btree_cur_t         *cur,   /* btree cursor */
-        xfs_btree_block_t       *block, /* generic btree block pointer */
-        int                     level,  /* level of the btree block */
-        xfs_buf_t               *bp)    /* buffer containing block, if any */
-{
-        if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
-                xfs_btree_check_lblock(cur, (xfs_btree_lblock_t *)block, level,
-                        bp);
-        else
-                xfs_btree_check_sblock(cur, (xfs_btree_sblock_t *)block, level,
-                        bp);
-}
-
-/*
  * Debug routine: check that keys are in the right order.
  */
 void
@@ -150,66 +132,8 @@ xfs_btree_check_key(
                 ASSERT(0);
         }
 }
-#endif  /* DEBUG */
-
-/*
- * Checking routine: check that long form block header is ok.
- */
-/* ARGSUSED */
-int                                     /* error (0 or EFSCORRUPTED) */
-xfs_btree_check_lblock(
-        xfs_btree_cur_t         *cur,   /* btree cursor */
-        xfs_btree_lblock_t      *block, /* btree long form block pointer */
-        int                     level,  /* level of the btree block */
-        xfs_buf_t               *bp)    /* buffer for block, if any */
-{
-        int                     lblock_ok; /* block passes checks */
-        xfs_mount_t             *mp;    /* file system mount point */
-
-        mp = cur->bc_mp;
-        lblock_ok =
-                be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
-                be16_to_cpu(block->bb_level) == level &&
-                be16_to_cpu(block->bb_numrecs) <=
-                        xfs_btree_maxrecs(cur, (xfs_btree_block_t *)block) &&
-                block->bb_leftsib &&
-                (be64_to_cpu(block->bb_leftsib) == NULLDFSBNO ||
-                 XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_leftsib))) &&
-                block->bb_rightsib &&
-                (be64_to_cpu(block->bb_rightsib) == NULLDFSBNO ||
-                 XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_rightsib)));
-        if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp, XFS_ERRTAG_BTREE_CHECK_LBLOCK,
-                        XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
-                if (bp)
-                        xfs_buftrace("LBTREE ERROR", bp);
-                XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
-                                 mp);
-                return XFS_ERROR(EFSCORRUPTED);
-        }
-        return 0;
-}
 
 /*
- * Checking routine: check that (long) pointer is ok.
- */
-int                                     /* error (0 or EFSCORRUPTED) */
-xfs_btree_check_lptr(
-        xfs_btree_cur_t *cur,           /* btree cursor */
-        xfs_dfsbno_t    ptr,            /* btree block disk address */
-        int             level)          /* btree block level */
-{
-        xfs_mount_t     *mp;            /* file system mount point */
-
-        mp = cur->bc_mp;
-        XFS_WANT_CORRUPTED_RETURN(
-                level > 0 &&
-                ptr != NULLDFSBNO &&
-                XFS_FSB_SANITY_CHECK(mp, ptr));
-        return 0;
-}
-
-#ifdef DEBUG
-/*
  * Debug routine: check that records are in the right order.
  */
 void
@@ -268,19 +192,49 @@ xfs_btree_check_rec(
 }
 #endif  /* DEBUG */
 
-/*
- * Checking routine: check that block header is ok.
- */
-/* ARGSUSED */
+int                                     /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_lblock(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        struct xfs_btree_lblock *block, /* btree long form block pointer */
+        int                     level,  /* level of the btree block */
+        struct xfs_buf          *bp)    /* buffer for block, if any */
+{
+        int                     lblock_ok; /* block passes checks */
+        struct xfs_mount        *mp;    /* file system mount point */
+
+        mp = cur->bc_mp;
+        lblock_ok =
+                be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
+                be16_to_cpu(block->bb_level) == level &&
+                be16_to_cpu(block->bb_numrecs) <=
+                        xfs_btree_maxrecs(cur, (xfs_btree_block_t *)block) &&
+                block->bb_leftsib &&
+                (be64_to_cpu(block->bb_leftsib) == NULLDFSBNO ||
+                 XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_leftsib))) &&
+                block->bb_rightsib &&
+                (be64_to_cpu(block->bb_rightsib) == NULLDFSBNO ||
+                 XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_rightsib)));
+        if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
+                        XFS_ERRTAG_BTREE_CHECK_LBLOCK,
+                        XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
+                if (bp)
+                        xfs_buftrace("LBTREE ERROR", bp);
+                XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
+                                 mp);
+                return XFS_ERROR(EFSCORRUPTED);
+        }
+        return 0;
+}
+
 int                                     /* error (0 or EFSCORRUPTED) */
 xfs_btree_check_sblock(
-        xfs_btree_cur_t         *cur,   /* btree cursor */
-        xfs_btree_sblock_t      *block, /* btree short form block pointer */
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        struct xfs_btree_sblock *block, /* btree short form block pointer */
         int                     level,  /* level of the btree block */
-        xfs_buf_t               *bp)    /* buffer containing block */
+        struct xfs_buf          *bp)    /* buffer containing block */
 {
-        xfs_buf_t               *agbp;  /* buffer for ag. freespace struct */
-        xfs_agf_t               *agf;   /* ag. freespace structure */
+        struct xfs_buf          *agbp;  /* buffer for ag. freespace struct */
+        struct xfs_agf          *agf;   /* ag. freespace structure */
         xfs_agblock_t           agflen; /* native ag. freespace length */
         int                     sblock_ok; /* block passes checks */
 
@@ -311,27 +265,79 @@ xfs_btree_check_sblock(
 }
 
 /*
- * Checking routine: check that (short) pointer is ok.
+ * Debug routine: check that block header is ok.
+ */
+int
+xfs_btree_check_block(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        struct xfs_btree_block  *block, /* generic btree block pointer */
+        int                     level,  /* level of the btree block */
+        struct xfs_buf          *bp)    /* buffer containing block, if any */
+{
+        if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+                return xfs_btree_check_lblock(cur,
+                                (struct xfs_btree_lblock *)block, level, bp);
+        } else {
+                return xfs_btree_check_sblock(cur,
+                                (struct xfs_btree_sblock *)block, level, bp);
+        }
+}
+
+/*
+ * Check that (long) pointer is ok.
+ */
+int                                     /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_lptr(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        xfs_dfsbno_t            bno,    /* btree block disk address */
+        int                     level)  /* btree block level */
+{
+        XFS_WANT_CORRUPTED_RETURN(
+                level > 0 &&
+                bno != NULLDFSBNO &&
+                XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
+        return 0;
+}
+
+/*
+ * Check that (short) pointer is ok.
  */
 int                                     /* error (0 or EFSCORRUPTED) */
 xfs_btree_check_sptr(
-        xfs_btree_cur_t *cur,           /* btree cursor */
-        xfs_agblock_t   ptr,            /* btree block disk address */
-        int             level)          /* btree block level */
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        xfs_agblock_t           bno,    /* btree block disk address */
+        int                     level)  /* btree block level */
 {
-        xfs_buf_t       *agbp;          /* buffer for ag. freespace struct */
-        xfs_agf_t       *agf;           /* ag. freespace structure */
+        xfs_agblock_t           agblocks = cur->bc_mp->m_sb.sb_agblocks;
 
-        agbp = cur->bc_private.a.agbp;
-        agf = XFS_BUF_TO_AGF(agbp);
         XFS_WANT_CORRUPTED_RETURN(
                 level > 0 &&
-                ptr != NULLAGBLOCK && ptr != 0 &&
-                ptr < be32_to_cpu(agf->agf_length));
+                bno != NULLAGBLOCK &&
+                bno != 0 &&
+                bno < agblocks);
         return 0;
 }
 
 /*
+ * Check that block ptr is ok.
+ */
+int                                     /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_ptr(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        union xfs_btree_ptr     *ptr,   /* btree block disk address */
+        int                     index,  /* offset from ptr to check */
+        int                     level)  /* btree block level */
+{
+        if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+                return xfs_btree_check_lptr(cur,
+                                be64_to_cpu((&ptr->l)[index]), level);
+        } else {
+                return xfs_btree_check_sptr(cur,
+                                be32_to_cpu((&ptr->s)[index]), level);
+        }
+}
+
+/*
  * Delete the btree cursor.
  */
 void
diff --git a/fs/xfs/xfs_btree.h b/fs/xfs/xfs_btree.h
index 8be838f0154a..a57918276d9f 100644
--- a/fs/xfs/xfs_btree.h
+++ b/fs/xfs/xfs_btree.h
@@ -215,81 +215,92 @@ typedef struct xfs_btree_cur
 
 #ifdef __KERNEL__
 
-#ifdef DEBUG
 /*
- * Debug routine: check that block header is ok.
+ * Check that long form block header is ok.
  */
-void
-xfs_btree_check_block(
-        xfs_btree_cur_t         *cur,   /* btree cursor */
-        xfs_btree_block_t       *block, /* generic btree block pointer */
+int                                     /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_lblock(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        struct xfs_btree_lblock *block, /* btree long form block pointer */
         int                     level,  /* level of the btree block */
         struct xfs_buf          *bp);   /* buffer containing block, if any */
 
 /*
- * Debug routine: check that keys are in the right order.
+ * Check that short form block header is ok.
  */
-void
-xfs_btree_check_key(
-        xfs_btnum_t             btnum,  /* btree identifier */
-        void                    *ak1,   /* pointer to left (lower) key */
-        void                    *ak2);  /* pointer to right (higher) key */
-
-/*
- * Debug routine: check that records are in the right order.
- */
-void
-xfs_btree_check_rec(
-        xfs_btnum_t             btnum,  /* btree identifier */
-        void                    *ar1,   /* pointer to left (lower) record */
-        void                    *ar2);  /* pointer to right (higher) record */
-#else
-#define xfs_btree_check_block(a,b,c,d)
-#define xfs_btree_check_key(a,b,c)
-#define xfs_btree_check_rec(a,b,c)
-#endif  /* DEBUG */
+int                                     /* error (0 or EFSCORRUPTED) */
+xfs_btree_check_sblock(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        struct xfs_btree_sblock *block, /* btree short form block pointer */
+        int                     level,  /* level of the btree block */
+        struct xfs_buf          *bp);   /* buffer containing block */
 
 /*
- * Checking routine: check that long form block header is ok.
+ * Check that block header is ok.
  */
-int                                     /* error (0 or EFSCORRUPTED) */
-xfs_btree_check_lblock(
-        xfs_btree_cur_t         *cur,   /* btree cursor */
-        xfs_btree_lblock_t      *block, /* btree long form block pointer */
+int
+xfs_btree_check_block(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        struct xfs_btree_block  *block, /* generic btree block pointer */
         int                     level,  /* level of the btree block */
         struct xfs_buf          *bp);   /* buffer containing block, if any */
 
 /*
- * Checking routine: check that (long) pointer is ok.
+ * Check that (long) pointer is ok.
  */
 int                                     /* error (0 or EFSCORRUPTED) */
 xfs_btree_check_lptr(
-        xfs_btree_cur_t         *cur,   /* btree cursor */
+        struct xfs_btree_cur    *cur,   /* btree cursor */
         xfs_dfsbno_t            ptr,    /* btree block disk address */
         int                     level); /* btree block level */
 
 #define xfs_btree_check_lptr_disk(cur, ptr, level) \
         xfs_btree_check_lptr(cur, be64_to_cpu(ptr), level)
 
+
 /*
- * Checking routine: check that short form block header is ok.
+ * Check that (short) pointer is ok.
  */
 int                                     /* error (0 or EFSCORRUPTED) */
-xfs_btree_check_sblock(
-        xfs_btree_cur_t         *cur,   /* btree cursor */
-        xfs_btree_sblock_t      *block, /* btree short form block pointer */
-        int                     level,  /* level of the btree block */
-        struct xfs_buf          *bp);   /* buffer containing block */
+xfs_btree_check_sptr(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        xfs_agblock_t           ptr,    /* btree block disk address */
+        int                     level); /* btree block level */
 
 /*
- * Checking routine: check that (short) pointer is ok.
+ * Check that (short) pointer is ok.
  */
 int                                     /* error (0 or EFSCORRUPTED) */
-xfs_btree_check_sptr(
-        xfs_btree_cur_t         *cur,   /* btree cursor */
-        xfs_agblock_t           ptr,    /* btree block disk address */
+xfs_btree_check_ptr(
+        struct xfs_btree_cur    *cur,   /* btree cursor */
+        union xfs_btree_ptr     *ptr,   /* btree block disk address */
+        int                     index,  /* offset from ptr to check */
         int                     level); /* btree block level */
 
+#ifdef DEBUG
+
+/*
+ * Debug routine: check that keys are in the right order.
+ */
+void
+xfs_btree_check_key(
+        xfs_btnum_t             btnum,  /* btree identifier */
+        void                    *ak1,   /* pointer to left (lower) key */
+        void                    *ak2);  /* pointer to right (higher) key */
+
+/*
+ * Debug routine: check that records are in the right order.
+ */
+void
+xfs_btree_check_rec(
+        xfs_btnum_t             btnum,  /* btree identifier */
+        void                    *ar1,   /* pointer to left (lower) record */
+        void                    *ar2);  /* pointer to right (higher) record */
+#else
+#define xfs_btree_check_key(a, b, c)
+#define xfs_btree_check_rec(a, b, c)
+#endif  /* DEBUG */
+
 /*
  * Delete the btree cursor.
  */