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| author | Amir Goldstein <amir73il@gmail.com> | 2018-01-17 15:40:27 +0300 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2018-01-24 13:26:05 +0300 |
| commit | 061701540349c30d72e48a201449a840c77ad509 (patch) | |
| tree | 46d3e9191ba287cd420af0a41bd5aba86bb50a89 /fs/overlayfs/namei.c | |
| parent | 4b91c30a5a19332e8dd10b601d05b72caf657730 (diff) | |
| download | linux-061701540349c30d72e48a201449a840c77ad509.tar.xz | |
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.c | 20 |
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; |