From: Darrick J. Wong <djwong@xxxxxxxxxx>
Source kernel commit: ea3d9e89f37160240af1c9f1706d17fea9e20ce9
Create a helper function to ensure that CoW staging extent records have
a single refcount and that shared extent records have more than 1
refcount. We'll put this to more use in the next patch.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
libxfs/xfs_refcount.c | 5 +----
libxfs/xfs_refcount.h | 12 ++++++++++++
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/libxfs/xfs_refcount.c b/libxfs/xfs_refcount.c
index 7094a27dce..f0fc96da6a 100644
--- a/libxfs/xfs_refcount.c
+++ b/libxfs/xfs_refcount.c
@@ -141,10 +141,7 @@ xfs_refcount_get_rec(
if (irec->rc_blockcount == 0 || irec->rc_blockcount > MAXREFCEXTLEN)
goto out_bad_rec;
- /* handle special COW-staging domain */
- if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)
- goto out_bad_rec;
- if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)
+ if (!xfs_refcount_check_domain(irec))
goto out_bad_rec;
/* check for valid extent range, including overflow */
diff --git a/libxfs/xfs_refcount.h b/libxfs/xfs_refcount.h
index 3beb5a30a9..ee32e8eb5a 100644
--- a/libxfs/xfs_refcount.h
+++ b/libxfs/xfs_refcount.h
@@ -55,6 +55,18 @@ struct xfs_refcount_intent {
xfs_fsblock_t ri_startblock;
};
+/* Check that the refcount is appropriate for the record domain. */
+static inline bool
+xfs_refcount_check_domain(
+ const struct xfs_refcount_irec *irec)
+{
+ if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)
+ return false;
+ if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)
+ return false;
+ return true;
+}
+
void xfs_refcount_increase_extent(struct xfs_trans *tp,
struct xfs_bmbt_irec *irec);
void xfs_refcount_decrease_extent(struct xfs_trans *tp,
