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| author |   Amir Goldstein <amir73il@gmail.com> | 2021-04-26 18:20:21 +0300 |
|---|---|---|
| committer |   Miklos Szeredi <mszeredi@redhat.com> | 2021-08-10 10:21:30 +0200 |
| commit | 9011c2791e63fc05721b545c41ad025d8073566e (patch) | |
| tree | 4168367806b39326e1abebf0607eb1b39ec5369f /fs | |
| parent | Linux 5.14-rc1 (diff) | |
| download | linux-dev-9011c2791e63fc05721b545c41ad025d8073566e.tar.xz linux-dev-9011c2791e63fc05721b545c41ad025d8073566e.zip | |
ovl: skip stale entries in merge dir cache iteration
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.
xfstest overlay/077 is failing without this patch.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/fstests/CAOQ4uxgR_cLnC_vdU5=seP3fwqVkuZM_-WfD6maFTMbMYq=a9w@mail.gmail.com/
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/overlayfs/readdir.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index e8ad2c2c77dd..150fdf3bc68d 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)) break; } |