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authorAmir Goldstein <amir73il@gmail.com>2018-01-17 14:40:27 +0200
committerMiklos Szeredi <mszeredi@redhat.com>2018-01-24 11:26:05 +0100
commit061701540349c30d72e48a201449a840c77ad509 (patch)
tree46d3e9191ba287cd420af0a41bd5aba86bb50a89 /fs/overlayfs/namei.c
parent4b91c30a5a19332e8dd10b601d05b72caf657730 (diff)
ovl: lookup indexed ancestor of lower dir
ovl_lookup_real() in lower layer walks back lower parents to find the topmost indexed parent. If an indexed ancestor is found before reaching lower layer root, ovl_lookup_real() is called recursively with upper layer to walk back from indexed upper to the topmost connected/hashed upper parent (or up to root). ovl_lookup_real() in upper layer then walks forward to connect the topmost upper overlay dir dentry and ovl_lookup_real() in lower layer continues to walk forward to connect the decoded lower overlay dir dentry. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/namei.c')
-rw-r--r--fs/overlayfs/namei.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 6199bf7a77c7..c5449efd96d5 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -661,11 +661,9 @@ struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh)
return ERR_PTR(err);
}
-static struct dentry *ovl_lookup_index(struct dentry *dentry,
- struct dentry *upper,
- struct dentry *origin)
+struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
+ struct dentry *origin, bool verify)
{
- struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
struct dentry *index;
struct inode *inode;
struct qstr name;
@@ -693,6 +691,16 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry,
inode = d_inode(index);
if (d_is_negative(index)) {
goto out_dput;
+ } else if (ovl_is_whiteout(index) && !verify) {
+ /*
+ * When index lookup is called with !verify for decoding an
+ * overlay file handle, a whiteout index implies that decode
+ * should treat file handle as stale and no need to print a
+ * warning about it.
+ */
+ dput(index);
+ index = ERR_PTR(-ESTALE);
+ goto out;
} else if (ovl_dentry_weird(index) || ovl_is_whiteout(index) ||
((inode->i_mode ^ d_inode(origin)->i_mode) & S_IFMT)) {
/*
@@ -706,7 +714,7 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry,
index, d_inode(index)->i_mode & S_IFMT,
d_inode(origin)->i_mode & S_IFMT);
goto fail;
- } else if (is_dir) {
+ } else if (is_dir && verify) {
if (!upper) {
pr_warn_ratelimited("overlayfs: suspected uncovered redirected dir found (origin=%pd2, index=%pd2).\n",
origin, index);
@@ -943,7 +951,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (origin && ovl_indexdir(dentry->d_sb) &&
(!d.is_dir || ovl_index_all(dentry->d_sb))) {
- index = ovl_lookup_index(dentry, upperdentry, origin);
+ index = ovl_lookup_index(ofs, upperdentry, origin, true);
if (IS_ERR(index)) {
err = PTR_ERR(index);
index = NULL;