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From:   Stephen Brennan <stephen.s.brennan@oracle.com>
To:     Alexander Viro <viro@zeniv.linux.org.uk>
Cc:     Stephen Brennan <stephen.s.brennan@oracle.com>,
        linux-kernel@vger.kernel.org, Luis Chamberlain <mcgrof@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Jan Kara <jack@suse.cz>, linux-fsdevel@vger.kernel.org,
        Arnd Bergmann <arnd@arndb.de>,
        Amir Goldstein <amir73il@gmail.com>
Subject: [PATCH v2 3/4] dcache: add action D_WALK_SKIP_SIBLINGS to d_walk()
Date:   Wed,  9 Feb 2022 15:14:05 -0800
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From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>

This lets skip remaining siblings at seeing d_is_tail_negative().

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com>
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
---
 fs/dcache.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/dcache.c b/fs/dcache.c
index 0960de9b9c36..8809643a4d5b 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1391,12 +1391,14 @@ EXPORT_SYMBOL(shrink_dcache_sb);
  * @D_WALK_QUIT:	quit walk
  * @D_WALK_NORETRY:	quit when retry is needed
  * @D_WALK_SKIP:	skip this dentry and its children
+ * @D_WALK_SKIP_SIBLINGS: skip siblings and their children
  */
 enum d_walk_ret {
 	D_WALK_CONTINUE,
 	D_WALK_QUIT,
 	D_WALK_NORETRY,
 	D_WALK_SKIP,
+	D_WALK_SKIP_SIBLINGS,
 };
 
 /**
@@ -1427,6 +1429,7 @@ static void d_walk(struct dentry *parent, void *data,
 		break;
 	case D_WALK_QUIT:
 	case D_WALK_SKIP:
+	case D_WALK_SKIP_SIBLINGS:
 		goto out_unlock;
 	case D_WALK_NORETRY:
 		retry = false;
@@ -1458,6 +1461,9 @@ static void d_walk(struct dentry *parent, void *data,
 		case D_WALK_SKIP:
 			spin_unlock(&dentry->d_lock);
 			continue;
+		case D_WALK_SKIP_SIBLINGS:
+			spin_unlock(&dentry->d_lock);
+			goto skip_siblings;
 		}
 
 		if (!list_empty(&dentry->d_subdirs)) {
@@ -1469,6 +1475,7 @@ static void d_walk(struct dentry *parent, void *data,
 		}
 		spin_unlock(&dentry->d_lock);
 	}
+skip_siblings:
 	/*
 	 * All done at this level ... ascend and resume the search.
 	 */
-- 
2.30.2