xfs: add CRC checks to the AGI

Same set of changes made to the AGF need to be made to the AGI.
This patch has a similar history to the AGF, hence a similar
sign-off chain.

Signed-off-by: Dave Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dgc@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 43 insertions, 14 deletions

diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index ba626613bf49..6d0a4954aa8c 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -36,6 +36,8 @@
 #include "xfs_rtalloc.h"
 #include "xfs_error.h"
 #include "xfs_bmap.h"
+#include "xfs_cksum.h"
+#include "xfs_buf_item.h"
 
 
 /*
@@ -1453,6 +1455,7 @@ xfs_ialloc_log_agi(
 	/*
 	 * Log the allocation group inode header buffer.
 	 */
+	xfs_trans_buf_set_type(tp, bp, XFS_BLF_AGI_BUF);
 	xfs_trans_log_buf(tp, bp, first, last);
 }
 
@@ -1470,19 +1473,23 @@ xfs_check_agi_unlinked(
 #define xfs_check_agi_unlinked(agi)
 #endif
 
-static void
+static bool
 xfs_agi_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;
 
+	if (xfs_sb_version_hascrc(&mp->m_sb) &&
+	    !uuid_equal(&agi->agi_uuid, &mp->m_sb.sb_uuid))
+			return false;
 	/*
 	 * 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));
+	if (agi->agi_magicnum != cpu_to_be32(XFS_AGI_MAGIC))
+		return false;
+	if (!XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum)))
+		return false;
 
 	/*
 	 * during growfs operations, the perag is not fully initialised,
@@ -1490,30 +1497,52 @@ xfs_agi_verify(
 	 * use it by using uncached buffers that don't have the perag attached
 	 * so we can detect and avoid this problem.
 	 */
-	if (bp->b_pag)
-		agi_ok = agi_ok && be32_to_cpu(agi->agi_seqno) ==
-						bp->b_pag->pag_agno;
+	if (bp->b_pag && be32_to_cpu(agi->agi_seqno) != bp->b_pag->pag_agno)
+		return false;
 
-	if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IALLOC_READ_AGI,
-			XFS_RANDOM_IALLOC_READ_AGI))) {
-		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, agi);
-		xfs_buf_ioerror(bp, EFSCORRUPTED);
-	}
 	xfs_check_agi_unlinked(agi);
+	return true;
 }
 
 static void
 xfs_agi_read_verify(
 	struct xfs_buf	*bp)
 {
-	xfs_agi_verify(bp);
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	int		agi_ok = 1;
+
+	if (xfs_sb_version_hascrc(&mp->m_sb))
+		agi_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+					  offsetof(struct xfs_agi, agi_crc));
+	agi_ok = agi_ok && xfs_agi_verify(bp);
+
+	if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IALLOC_READ_AGI,
+			XFS_RANDOM_IALLOC_READ_AGI))) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+	}
 }
 
 static void
 xfs_agi_write_verify(
 	struct xfs_buf	*bp)
 {
-	xfs_agi_verify(bp);
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	struct xfs_buf_log_item	*bip = bp->b_fspriv;
+
+	if (!xfs_agi_verify(bp)) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+		return;
+	}
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return;
+
+	if (bip)
+		XFS_BUF_TO_AGI(bp)->agi_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+			 offsetof(struct xfs_agi, agi_crc));
 }
 
 const struct xfs_buf_ops xfs_agi_buf_ops = {