Note: the mount options index=off,nfs_export=on are conflicting for a
read-write mount and will result in an error.
+Note: the mount option uuid=off can be used to replace UUID of the underlying
+filesystem in file handles with null, and effectively disable UUID checks. This
+can be useful in case the underlying disk is copied and the UUID of this copy
+is changed. This is only applicable if all lower/upper/work directories are on
+the same filesystem, otherwise it will fallback to normal behaviour.
Volatile mount
--------------
/*
* Make sure that the stored uuid matches the uuid of the lower
* layer where file handle will be decoded.
+ * In case of uuid=off option just make sure that stored uuid is null.
*/
- if (!uuid_equal(&fh->fb.uuid, &mnt->mnt_sb->s_uuid))
+ if (ofs->config.uuid ? !uuid_equal(&fh->fb.uuid, &mnt->mnt_sb->s_uuid) :
+ !uuid_is_null(&fh->fb.uuid))
return NULL;
bytes = (fh->fb.len - offsetof(struct ovl_fb, fid));
seq_printf(m, ",redirect_dir=%s", ofs->config.redirect_mode);
if (ofs->config.index != ovl_index_def)
seq_printf(m, ",index=%s", ofs->config.index ? "on" : "off");
+ if (!ofs->config.uuid)
+ seq_puts(m, ",uuid=off");
if (ofs->config.nfs_export != ovl_nfs_export_def)
seq_printf(m, ",nfs_export=%s", ofs->config.nfs_export ?
"on" : "off");
OPT_REDIRECT_DIR,
OPT_INDEX_ON,
OPT_INDEX_OFF,
+ OPT_UUID_ON,
+ OPT_UUID_OFF,
OPT_NFS_EXPORT_ON,
OPT_NFS_EXPORT_OFF,
OPT_XINO_ON,
{OPT_REDIRECT_DIR, "redirect_dir=%s"},
{OPT_INDEX_ON, "index=on"},
{OPT_INDEX_OFF, "index=off"},
+ {OPT_UUID_ON, "uuid=on"},
+ {OPT_UUID_OFF, "uuid=off"},
{OPT_NFS_EXPORT_ON, "nfs_export=on"},
{OPT_NFS_EXPORT_OFF, "nfs_export=off"},
{OPT_XINO_ON, "xino=on"},
index_opt = true;
break;
+ case OPT_UUID_ON:
+ config->uuid = true;
+ break;
+
+ case OPT_UUID_OFF:
+ config->uuid = false;
+ break;
+
case OPT_NFS_EXPORT_ON:
config->nfs_export = true;
nfs_export_opt = true;
ofs->share_whiteout = true;
ofs->config.index = ovl_index_def;
+ ofs->config.uuid = true;
ofs->config.nfs_export = ovl_nfs_export_def;
ofs->config.xino = ovl_xino_def();
ofs->config.metacopy = ovl_metacopy_def;
if (!ovl_upper_mnt(ofs))
sb->s_flags |= SB_RDONLY;
+ if (!ofs->config.uuid && ofs->numfs > 1) {
+ pr_warn("The uuid=off requires a single fs for lower and upper, falling back to uuid=on.\n");
+ ofs->config.uuid = true;
+ }
+
if (!ovl_force_readonly(ofs) && ofs->config.index) {
err = ovl_get_indexdir(sb, ofs, oe, &upperpath);
if (err)