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From: Amir Goldstein <>
To: Miklos Szeredi <>
Subject: [PATCH] ovl: skip stale entries in merge dir cache iteration
Date: Mon, 26 Apr 2021 18:20:21 +0300	[thread overview]
Message-ID: <> (raw)

On the first getdents call, ovl_iterate() populates the readdir cache
with a list of entries, but for upper entries with origin lower inode,
p->ino remains zero.

Following getdents calls traverse the readdir cache list and call
ovl_cache_update_ino() for entries with zero p->ino to lookup the entry
in the overlay and return d_ino that is consistent with st_ino.

If the upper file was unlinked between the first getdents call and the
getdents call that lists the file entry, ovl_cache_update_ino() will not
find the entry and fall back to setting d_ino to the upper real st_ino,
which is inconsistent with how this object was presented to users.

Instead of listing a stale entry with inconsistent d_ino, simply skip
the stale entry, which is better for users.

Signed-off-by: Amir Goldstein <>
 fs/overlayfs/readdir.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index cc1e80257064..10b7780e4bdc 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -481,6 +481,8 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
 	this = lookup_one_len(p->name, dir, p->len);
 	if (IS_ERR_OR_NULL(this) || !this->d_inode) {
+		/* Mark a stale entry */
+		p->is_whiteout = true;
 		if (IS_ERR(this)) {
 			err = PTR_ERR(this);
 			this = NULL;
@@ -776,6 +778,9 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
 				if (err)
 					goto out;
+		}
+		/* ovl_cache_update_ino() sets is_whiteout on stale entry */
+		if (!p->is_whiteout) {
 			if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))

             reply	other threads:[~2021-04-26 15:20 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-26 15:20 Amir Goldstein [this message]
2021-06-04 10:43 ` [PATCH] ovl: skip stale entries in merge dir cache iteration Amir Goldstein
2021-07-19 15:24   ` Miklos Szeredi
2021-07-19 16:43     ` Amir Goldstein
2021-07-20  4:19       ` Miklos Szeredi
2021-07-20  4:22         ` Miklos Szeredi
2021-07-20  7:18           ` Amir Goldstein
2021-07-20 14:55             ` Amir Goldstein
2021-07-20 16:17               ` Amir Goldstein
2021-07-21 13:08                 ` Miklos Szeredi

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