v4.19.13 snapshot.
diff --git a/fs/cifs/cache.c b/fs/cifs/cache.c
new file mode 100644
index 0000000..b7420e6
--- /dev/null
+++ b/fs/cifs/cache.c
@@ -0,0 +1,146 @@
+/*
+ * fs/cifs/cache.c - CIFS filesystem cache index structure definitions
+ *
+ * Copyright (c) 2010 Novell, Inc.
+ * Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "fscache.h"
+#include "cifs_debug.h"
+
+/*
+ * CIFS filesystem definition for FS-Cache
+ */
+struct fscache_netfs cifs_fscache_netfs = {
+ .name = "cifs",
+ .version = 0,
+};
+
+/*
+ * Register CIFS for caching with FS-Cache
+ */
+int cifs_fscache_register(void)
+{
+ return fscache_register_netfs(&cifs_fscache_netfs);
+}
+
+/*
+ * Unregister CIFS for caching
+ */
+void cifs_fscache_unregister(void)
+{
+ fscache_unregister_netfs(&cifs_fscache_netfs);
+}
+
+/*
+ * Server object for FS-Cache
+ */
+const struct fscache_cookie_def cifs_fscache_server_index_def = {
+ .name = "CIFS.server",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+};
+
+/*
+ * Auxiliary data attached to CIFS superblock within the cache
+ */
+struct cifs_fscache_super_auxdata {
+ u64 resource_id; /* unique server resource id */
+};
+
+char *extract_sharename(const char *treename)
+{
+ const char *src;
+ char *delim, *dst;
+ int len;
+
+ /* skip double chars at the beginning */
+ src = treename + 2;
+
+ /* share name is always preceded by '\\' now */
+ delim = strchr(src, '\\');
+ if (!delim)
+ return ERR_PTR(-EINVAL);
+ delim++;
+ len = strlen(delim);
+
+ /* caller has to free the memory */
+ dst = kstrndup(delim, len, GFP_KERNEL);
+ if (!dst)
+ return ERR_PTR(-ENOMEM);
+
+ return dst;
+}
+
+static enum
+fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
+ const void *data,
+ uint16_t datalen,
+ loff_t object_size)
+{
+ struct cifs_fscache_super_auxdata auxdata;
+ const struct cifs_tcon *tcon = cookie_netfs_data;
+
+ if (datalen != sizeof(auxdata))
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ memset(&auxdata, 0, sizeof(auxdata));
+ auxdata.resource_id = tcon->resource_id;
+
+ if (memcmp(data, &auxdata, datalen) != 0)
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ return FSCACHE_CHECKAUX_OKAY;
+}
+
+/*
+ * Superblock object for FS-Cache
+ */
+const struct fscache_cookie_def cifs_fscache_super_index_def = {
+ .name = "CIFS.super",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .check_aux = cifs_fscache_super_check_aux,
+};
+
+static enum
+fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
+ const void *data,
+ uint16_t datalen,
+ loff_t object_size)
+{
+ struct cifs_fscache_inode_auxdata auxdata;
+ struct cifsInodeInfo *cifsi = cookie_netfs_data;
+
+ if (datalen != sizeof(auxdata))
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ memset(&auxdata, 0, sizeof(auxdata));
+ auxdata.eof = cifsi->server_eof;
+ auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
+ auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
+ auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
+ auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
+
+ if (memcmp(data, &auxdata, datalen) != 0)
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ return FSCACHE_CHECKAUX_OKAY;
+}
+
+const struct fscache_cookie_def cifs_fscache_inode_object_def = {
+ .name = "CIFS.uniqueid",
+ .type = FSCACHE_COOKIE_TYPE_DATAFILE,
+ .check_aux = cifs_fscache_inode_check_aux,
+};