[CIFS] Migrate from prefixpath logic
Now we point superblock to a server share root and set a root dentry
appropriately. This let us share superblock between mounts like
//server/sharename/foo/bar and //server/sharename/foo further.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 1d2a93c..46fdd55 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -415,8 +415,6 @@
seq_printf(s, ",nocase");
if (tcon->retry)
seq_printf(s, ",hard");
- if (cifs_sb->prepath)
- seq_printf(s, ",prepath=%s", cifs_sb->prepath);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
seq_printf(s, ",posixpaths");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)
@@ -530,6 +528,100 @@
#endif
};
+/*
+ * Get root dentry from superblock according to prefix path mount option.
+ * Return dentry with refcount + 1 on success and NULL otherwise.
+ */
+static struct dentry *
+cifs_get_root(struct smb_vol *vol, struct super_block *sb)
+{
+ int xid, rc;
+ struct inode *inode;
+ struct qstr name;
+ struct dentry *dparent = NULL, *dchild = NULL, *alias;
+ struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+ unsigned int i, full_len, len;
+ char *full_path = NULL, *pstart;
+ char sep;
+
+ full_path = cifs_build_path_to_root(vol, cifs_sb,
+ cifs_sb_master_tcon(cifs_sb));
+ if (full_path == NULL)
+ return NULL;
+
+ cFYI(1, "Get root dentry for %s", full_path);
+
+ xid = GetXid();
+ sep = CIFS_DIR_SEP(cifs_sb);
+ dparent = dget(sb->s_root);
+ full_len = strlen(full_path);
+ full_path[full_len] = sep;
+ pstart = full_path + 1;
+
+ for (i = 1, len = 0; i <= full_len; i++) {
+ if (full_path[i] != sep || !len) {
+ len++;
+ continue;
+ }
+
+ full_path[i] = 0;
+ cFYI(1, "get dentry for %s", pstart);
+
+ name.name = pstart;
+ name.len = len;
+ name.hash = full_name_hash(pstart, len);
+ dchild = d_lookup(dparent, &name);
+ if (dchild == NULL) {
+ cFYI(1, "not exists");
+ dchild = d_alloc(dparent, &name);
+ if (dchild == NULL) {
+ dput(dparent);
+ dparent = NULL;
+ goto out;
+ }
+ }
+
+ cFYI(1, "get inode");
+ if (dchild->d_inode == NULL) {
+ cFYI(1, "not exists");
+ inode = NULL;
+ if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
+ rc = cifs_get_inode_info_unix(&inode, full_path,
+ sb, xid);
+ else
+ rc = cifs_get_inode_info(&inode, full_path,
+ NULL, sb, xid, NULL);
+ if (rc) {
+ dput(dchild);
+ dput(dparent);
+ dparent = NULL;
+ goto out;
+ }
+ alias = d_materialise_unique(dchild, inode);
+ if (alias != NULL) {
+ dput(dchild);
+ if (IS_ERR(alias)) {
+ dput(dparent);
+ dparent = NULL;
+ goto out;
+ }
+ dchild = alias;
+ }
+ }
+ cFYI(1, "parent %p, child %p", dparent, dchild);
+
+ dput(dparent);
+ dparent = dchild;
+ len = 0;
+ pstart = full_path + i + 1;
+ full_path[i] = sep;
+ }
+out:
+ _FreeXid(xid);
+ kfree(full_path);
+ return dparent;
+}
+
static struct dentry *
cifs_do_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
@@ -585,7 +677,10 @@
sb->s_flags |= MS_ACTIVE;
- root = dget(sb->s_root);
+ root = cifs_get_root(volume_info, sb);
+ if (root == NULL)
+ goto out_super;
+ cFYI(1, "dentry root is: %p", root);
goto out;
out_super: