xfs: hoist recovered bmap intent checks out of xfs_bui_item_recover

When we recover a bmap intent from the log, we need to validate its
contents before we try to replay them.  Hoist the checking code into a
separate function in preparation to refactor this code to use validation
helpers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c
index 9e16a4d..9be61fe 100644 (file)
--- a/fs/xfs/xfs_bmap_item.c
+++ b/fs/xfs/xfs_bmap_item.c
@@ -417,6 +417,49 @@ const struct xfs_defer_op_type xfs_bmap_update_defer_type = {
        .cancel_item    = xfs_bmap_update_cancel_item,
 };
 
+/* Is this recovered BUI ok? */
+static inline bool
+xfs_bui_validate(
+       struct xfs_mount                *mp,
+       struct xfs_bui_log_item         *buip)
+{
+       struct xfs_map_extent           *bmap;
+       xfs_fsblock_t                   startblock_fsb;
+       xfs_fsblock_t                   inode_fsb;
+
+       /* Only one mapping operation per BUI... */
+       if (buip->bui_format.bui_nextents != XFS_BUI_MAX_FAST_EXTENTS)
+               return false;
+
+       bmap = &buip->bui_format.bui_extents[0];
+       startblock_fsb = XFS_BB_TO_FSB(mp,
+                       XFS_FSB_TO_DADDR(mp, bmap->me_startblock));
+       inode_fsb = XFS_BB_TO_FSB(mp, XFS_FSB_TO_DADDR(mp,
+                       XFS_INO_TO_FSB(mp, bmap->me_owner)));
+
+       if (bmap->me_flags & ~XFS_BMAP_EXTENT_FLAGS)
+               return false;
+
+       switch (bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK) {
+       case XFS_BMAP_MAP:
+       case XFS_BMAP_UNMAP:
+               break;
+       default:
+               return false;
+       }
+
+       if (startblock_fsb == 0 ||
+           bmap->me_len == 0 ||
+           inode_fsb == 0 ||
+           startblock_fsb >= mp->m_sb.sb_dblocks ||
+           bmap->me_len >= mp->m_sb.sb_agblocks ||
+           inode_fsb >= mp->m_sb.sb_dblocks ||
+           (bmap->me_flags & ~XFS_BMAP_EXTENT_FLAGS))
+               return false;
+
+       return true;
+}
+
 /*
  * Process a bmap update intent item that was recovered from the log.
  * We need to update some inode's bmbt.
@@ -433,47 +476,24 @@ xfs_bui_item_recover(
        struct xfs_mount                *mp = lip->li_mountp;
        struct xfs_map_extent           *bmap;
        struct xfs_bud_log_item         *budp;
-       xfs_fsblock_t                   startblock_fsb;
-       xfs_fsblock_t                   inode_fsb;
        xfs_filblks_t                   count;
        xfs_exntst_t                    state;
        unsigned int                    bui_type;
        int                             whichfork;
        int                             error = 0;
 
-       /* Only one mapping operation per BUI... */
-       if (buip->bui_format.bui_nextents != XFS_BUI_MAX_FAST_EXTENTS)
+       if (!xfs_bui_validate(mp, buip)) {
+               XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+                               &buip->bui_format, sizeof(buip->bui_format));
                return -EFSCORRUPTED;
+       }
 
-       /*
-        * First check the validity of the extent described by the
-        * BUI.  If anything is bad, then toss the BUI.
-        */
        bmap = &buip->bui_format.bui_extents[0];
-       startblock_fsb = XFS_BB_TO_FSB(mp,
-                          XFS_FSB_TO_DADDR(mp, bmap->me_startblock));
-       inode_fsb = XFS_BB_TO_FSB(mp, XFS_FSB_TO_DADDR(mp,
-                       XFS_INO_TO_FSB(mp, bmap->me_owner)));
        state = (bmap->me_flags & XFS_BMAP_EXTENT_UNWRITTEN) ?
                        XFS_EXT_UNWRITTEN : XFS_EXT_NORM;
        whichfork = (bmap->me_flags & XFS_BMAP_EXTENT_ATTR_FORK) ?
                        XFS_ATTR_FORK : XFS_DATA_FORK;
        bui_type = bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK;
-       switch (bui_type) {
-       case XFS_BMAP_MAP:
-       case XFS_BMAP_UNMAP:
-               break;
-       default:
-               return -EFSCORRUPTED;
-       }
-       if (startblock_fsb == 0 ||
-           bmap->me_len == 0 ||
-           inode_fsb == 0 ||
-           startblock_fsb >= mp->m_sb.sb_dblocks ||
-           bmap->me_len >= mp->m_sb.sb_agblocks ||
-           inode_fsb >= mp->m_sb.sb_dblocks ||
-           (bmap->me_flags & ~XFS_BMAP_EXTENT_FLAGS))
-               return -EFSCORRUPTED;
 
        /* Grab the inode. */
        error = xfs_iget(mp, NULL, bmap->me_owner, 0, 0, &ip);