xfs: place intent recovery under NOFS allocation context

When recovery starts processing intents, all of the initial intent
allocations are done outside of transaction contexts. That means
they need to specifically use GFP_NOFS as we do not want memory
reclaim to attempt to run direct reclaim of filesystem objects while
we have lots of objects added into deferred operations.

Rather than use GFP_NOFS for these specific allocations, just place
the entire intent recovery process under NOFS context and we can
then just use GFP_KERNEL for these allocations.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

1 files changed, 14 insertions, 4 deletions

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index e9ed43a833af..8c1d260bb9e1 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -3443,12 +3443,19 @@ xlog_recover(
  * part of recovery so that the root and real-time bitmap inodes can be read in
  * from disk in between the two stages.  This is necessary so that we can free
  * space in the real-time portion of the file system.
+ *
+ * We run this whole process under GFP_NOFS allocation context. We do a
+ * combination of non-transactional and transactional work, yet we really don't
+ * want to recurse into the filesystem from direct reclaim during any of this
+ * processing. This allows all the recovery code run here not to care about the
+ * memory allocation context it is running in.
  */
 int
 xlog_recover_finish(
 	struct xlog	*log)
 {
-	int	error;
+	unsigned int	nofs_flags = memalloc_nofs_save();
+	int		error;
 
 	error = xlog_recover_process_intents(log);
 	if (error) {
@@ -3462,7 +3469,7 @@ xlog_recover_finish(
 		xlog_recover_cancel_intents(log);
 		xfs_alert(log->l_mp, "Failed to recover intents");
 		xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
-		return error;
+		goto out_error;
 	}
 
 	/*
@@ -3483,7 +3490,7 @@ xlog_recover_finish(
 		if (error < 0) {
 			xfs_alert(log->l_mp,
 	"Failed to clear log incompat features on recovery");
-			return error;
+			goto out_error;
 		}
 	}
 
@@ -3508,9 +3515,12 @@ xlog_recover_finish(
 		 * and AIL.
 		 */
 		xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
+		goto out_error;
 	}
 
-	return 0;
+out_error:
+	memalloc_nofs_restore(nofs_flags);
+	return error;
 }
 
 void