[PATCH 01/10] xfs: hoist recovered bmap intent checks out of xfs_bui_item_recover

Darrick J. Wong
2020-12-04T01:12:31Z

From: Darrick J. Wong <darrick.wong@oracle.com>

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>
---
fs/xfs/xfs_bmap_item.c | 73 ++++++++++++++++++++++++++++++------------------
1 file changed, 46 insertions(+), 27 deletions(-)

diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c
index 9e16a4d0f97c..555453d0e080 100644
--- 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 +476,23 @@ 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_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
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);