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-rw-r--r--fs/overlayfs/copy_up.c122
-rw-r--r--fs/overlayfs/util.c2
2 files changed, 117 insertions, 7 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 103e62dcb745..8ef25d8c3cfe 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -315,6 +315,94 @@ int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
return err;
}
+/* Store file handle of @upper dir in @index dir entry */
+static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index)
+{
+ const struct ovl_fh *fh;
+ int err;
+
+ fh = ovl_encode_fh(upper, true);
+ if (IS_ERR(fh))
+ return PTR_ERR(fh);
+
+ err = ovl_do_setxattr(index, OVL_XATTR_UPPER, fh, fh->len, 0);
+
+ kfree(fh);
+ return err;
+}
+
+/*
+ * Create and install index entry.
+ *
+ * Caller must hold i_mutex on indexdir.
+ */
+static int ovl_create_index(struct dentry *dentry, struct dentry *origin,
+ struct dentry *upper)
+{
+ struct dentry *indexdir = ovl_indexdir(dentry->d_sb);
+ struct inode *dir = d_inode(indexdir);
+ struct dentry *index = NULL;
+ struct dentry *temp = NULL;
+ struct qstr name = { };
+ int err;
+
+ /*
+ * For now this is only used for creating index entry for directories,
+ * because non-dir are copied up directly to index and then hardlinked
+ * to upper dir.
+ *
+ * TODO: implement create index for non-dir, so we can call it when
+ * encoding file handle for non-dir in case index does not exist.
+ */
+ if (WARN_ON(!d_is_dir(dentry)))
+ return -EIO;
+
+ /* Directory not expected to be indexed before copy up */
+ if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry))))
+ return -EIO;
+
+ err = ovl_get_index_name(origin, &name);
+ if (err)
+ return err;
+
+ temp = ovl_lookup_temp(indexdir);
+ if (IS_ERR(temp))
+ goto temp_err;
+
+ err = ovl_do_mkdir(dir, temp, S_IFDIR, true);
+ if (err)
+ goto out;
+
+ err = ovl_set_upper_fh(upper, temp);
+ if (err)
+ goto out_cleanup;
+
+ index = lookup_one_len(name.name, indexdir, name.len);
+ if (IS_ERR(index)) {
+ err = PTR_ERR(index);
+ } else {
+ err = ovl_do_rename(dir, temp, dir, index, 0);
+ dput(index);
+ }
+
+ if (err)
+ goto out_cleanup;
+
+out:
+ dput(temp);
+ kfree(name.name);
+ return err;
+
+temp_err:
+ err = PTR_ERR(temp);
+ temp = NULL;
+ goto out;
+
+out_cleanup:
+ ovl_cleanup(dir, temp);
+ goto out;
+}
+
struct ovl_copy_up_ctx {
struct dentry *parent;
struct dentry *dentry;
@@ -327,6 +415,7 @@ struct ovl_copy_up_ctx {
struct dentry *workdir;
bool tmpfile;
bool origin;
+ bool indexed;
};
static int ovl_link_up(struct ovl_copy_up_ctx *c)
@@ -498,6 +587,12 @@ static int ovl_copy_up_locked(struct ovl_copy_up_ctx *c)
if (err)
goto out_cleanup;
+ if (S_ISDIR(c->stat.mode) && c->indexed) {
+ err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp);
+ if (err)
+ goto out_cleanup;
+ }
+
if (c->tmpfile) {
inode_lock_nested(udir, I_MUTEX_PARENT);
err = ovl_install_temp(c, temp, &newdentry);
@@ -536,12 +631,26 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
{
int err;
struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info;
- bool indexed = ovl_need_index(c->dentry);
+ bool to_index = false;
- if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || indexed)
+ /*
+ * Indexed non-dir is copied up directly to the index entry and then
+ * hardlinked to upper dir. Indexed dir is copied up to indexdir,
+ * then index entry is created and then copied up dir installed.
+ * Copying dir up to indexdir instead of workdir simplifies locking.
+ */
+ if (ovl_need_index(c->dentry)) {
+ c->indexed = true;
+ if (S_ISDIR(c->stat.mode))
+ c->workdir = ovl_indexdir(c->dentry->d_sb);
+ else
+ to_index = true;
+ }
+
+ if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index)
c->origin = true;
- if (indexed) {
+ if (to_index) {
c->destdir = ovl_indexdir(c->dentry->d_sb);
err = ovl_get_index_name(c->lowerpath.dentry, &c->destname);
if (err)
@@ -568,9 +677,10 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
}
}
- if (indexed) {
- if (!err)
- ovl_set_flag(OVL_INDEX, d_inode(c->dentry));
+ if (!err && c->indexed)
+ ovl_set_flag(OVL_INDEX, d_inode(c->dentry));
+
+ if (to_index) {
kfree(c->destname.name);
} else if (!err) {
struct inode *udir = d_inode(c->destdir);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 7cb930e367be..71ddc4f8864e 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -474,7 +474,7 @@ bool ovl_need_index(struct dentry *dentry)
return false;
/* Index all files for NFS export and consistency verification */
- if (!d_is_dir(lower) && ovl_index_all(dentry->d_sb))
+ if (ovl_index_all(dentry->d_sb))
return true;
/* Index only lower hardlinks on copy up */