[PATCH 06/19] xfs: verify AGI blocks as they are read from disk

Dave Chinner
2012-10-09T03:49:59Z

Add an AGI block verify callback function and pass it into the
buffer read functions. Remove the now redundant verification code
that is currently in use.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_ialloc.c | 47 ++++++++++++++++++++++++++---------------------
1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index 7c944e1..9311ae5 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -1472,6 +1472,31 @@ xfs_check_agi_unlinked(
#define xfs_check_agi_unlinked(agi)
#endif

+static void
+xfs_agi_read_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+ struct xfs_agi *agi = XFS_BUF_TO_AGI(bp);
+ int agi_ok;
+
+ /*
+ * Validate the magic number of the agi block.
+ */
+ agi_ok = agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC) &&
+ XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum)) &&
+ be32_to_cpu(agi->agi_seqno) == bp->b_pag->pag_agno;
+ if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IALLOC_READ_AGI,
+ XFS_RANDOM_IALLOC_READ_AGI))) {
+ XFS_CORRUPTION_ERROR("xfs_read_agi", XFS_ERRLEVEL_LOW,
+ mp, agi);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ }
+ xfs_check_agi_unlinked(agi);
+ bp->b_iodone = NULL;
+ xfs_buf_ioend(bp, 0);
+}
+
/*
* Read in the allocation group header (inode allocation section)
*/
@@ -1482,38 +1507,18 @@ xfs_read_agi(
xfs_agnumber_t agno, /* allocation group number */
struct xfs_buf **bpp) /* allocation group hdr buf */
{
- struct xfs_agi *agi; /* allocation group header */
- int agi_ok; /* agi is consistent */
int error;

ASSERT(agno != NULLAGNUMBER);

error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
- XFS_FSS_TO_BB(mp, 1), 0, bpp, NULL);
+ XFS_FSS_TO_BB(mp, 1), 0, bpp, xfs_agi_read_verify);
if (error)
return error;

ASSERT(!xfs_buf_geterror(*bpp));
- agi = XFS_BUF_TO_AGI(*bpp);
-
- /*
- * Validate the magic number of the agi block.
- */
- agi_ok = agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC) &&
- XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum)) &&
- be32_to_cpu(agi->agi_seqno) == agno;
- if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IALLOC_READ_AGI,
- XFS_RANDOM_IALLOC_READ_AGI))) {
- XFS_CORRUPTION_ERROR("xfs_read_agi", XFS_ERRLEVEL_LOW,
- mp, agi);
- xfs_trans_brelse(tp, *bpp);
- return XFS_ERROR(EFSCORRUPTED);
- }
-
xfs_buf_set_ref(*bpp, XFS_AGI_REF);
-
- xfs_check_agi_unlinked(agi);
return 0;