xfs: repair inode fork block mapping data structures

Use the reverse-mapping btree information to rebuild an inode block map.
Update the btree bulk loading code as necessary to support inode rooted
btrees and fix some bitrot problems.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 62 insertions, 0 deletions

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 305c9d07bf1b..12d45e93f07d 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -1237,6 +1237,68 @@ out_cancel:
 }
 
 /*
+ * Try to reserve more blocks for a transaction.
+ *
+ * This is for callers that need to attach resources to a transaction, scan
+ * those resources to determine the space reservation requirements, and then
+ * modify the attached resources.  In other words, online repair.  This can
+ * fail due to ENOSPC, so the caller must be able to cancel the transaction
+ * without shutting down the fs.
+ */
+int
+xfs_trans_reserve_more(
+	struct xfs_trans	*tp,
+	unsigned int		blocks,
+	unsigned int		rtextents)
+{
+	struct xfs_trans_res	resv = { };
+
+	return xfs_trans_reserve(tp, &resv, blocks, rtextents);
+}
+
+/*
+ * Try to reserve more blocks and file quota for a transaction.  Same
+ * conditions of usage as xfs_trans_reserve_more.
+ */
+int
+xfs_trans_reserve_more_inode(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	unsigned int		dblocks,
+	unsigned int		rblocks,
+	bool			force_quota)
+{
+	struct xfs_trans_res	resv = { };
+	struct xfs_mount	*mp = ip->i_mount;
+	unsigned int		rtx = xfs_extlen_to_rtxlen(mp, rblocks);
+	int			error;
+
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	error = xfs_trans_reserve(tp, &resv, dblocks, rtx);
+	if (error)
+		return error;
+
+	if (!XFS_IS_QUOTA_ON(mp) || xfs_is_quota_inode(&mp->m_sb, ip->i_ino))
+		return 0;
+
+	if (tp->t_flags & XFS_TRANS_RESERVE)
+		force_quota = true;
+
+	error = xfs_trans_reserve_quota_nblks(tp, ip, dblocks, rblocks,
+			force_quota);
+	if (!error)
+		return 0;
+
+	/* Quota failed, give back the new reservation. */
+	xfs_mod_fdblocks(mp, dblocks, tp->t_flags & XFS_TRANS_RESERVE);
+	tp->t_blk_res -= dblocks;
+	xfs_mod_frextents(mp, rtx);
+	tp->t_rtx_res -= rtx;
+	return error;
+}
+
+/*
  * Allocate an transaction in preparation for inode creation by reserving quota
  * against the given dquots.  Callers are not required to hold any inode locks.
  */