Revert "xfs: fix filesystsem freeze race in xfs_trans_alloc"
This reverts commit 7a249cf83da1813cfa71cfe1e265b40045eceb47.
That commit created a situation that could lead to a filesystem
hang. As Dave Chinner pointed out, xfs_trans_alloc() could hold a
reference to m_active_trans (i.e., keep it non-zero) and then wait
for SB_FREEZE_TRANS to complete. Meanwhile a filesystem freeze
request could set SB_FREEZE_TRANS and then wait for m_active_trans
to drop to zero. Nobody benefits from this sequence of events...
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 2be5e5c..a19e923 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1559,9 +1559,15 @@
}
/*
+ * xfs_log_sbcount
+ *
* Called either periodically to keep the on disk superblock values
* roughly up to date or from unmount to make sure the values are
* correct on a clean unmount.
+ *
+ * Note this code can be called during the process of freezing, so
+ * we may need to use the transaction allocator which does not not
+ * block when the transaction subsystem is in its frozen state.
*/
int
xfs_log_sbcount(
@@ -1583,13 +1589,7 @@
if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
return 0;
- /*
- * We can be called during the process of freezing, so make sure
- * we go ahead even if the frozen for new transactions. We will
- * always use a sync transaction in the freeze path to make sure
- * the transaction has completed by the time we return.
- */
- tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP, false);
+ tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);
error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
XFS_DEFAULT_LOG_COUNT);
if (error) {