diff options
Diffstat (limited to 'fs/overlayfs/util.c')
| -rw-r--r-- | fs/overlayfs/util.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 500133f196d7..8602982ae579 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -676,6 +676,43 @@ bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path) return false; } +/* + * Load persistent uuid from xattr into s_uuid if found, or store a new + * random generated value in s_uuid and in xattr. + */ +bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, + const struct path *upperpath) +{ + bool set = false; + int res; + + /* Try to load existing persistent uuid */ + res = ovl_path_getxattr(ofs, upperpath, OVL_XATTR_UUID, sb->s_uuid.b, + UUID_SIZE); + if (res == UUID_SIZE) + return true; + + if (res != -ENODATA) + goto fail; + + /* Generate overlay instance uuid */ + uuid_gen(&sb->s_uuid); + + /* Try to store persistent uuid */ + set = true; + res = ovl_setxattr(ofs, upperpath->dentry, OVL_XATTR_UUID, sb->s_uuid.b, + UUID_SIZE); + if (res == 0) + return true; + +fail: + memset(sb->s_uuid.b, 0, UUID_SIZE); + ofs->config.uuid = OVL_UUID_NULL; + pr_warn("failed to %s uuid (%pd2, err=%i); falling back to uuid=null.\n", + set ? "set" : "get", upperpath->dentry, res); + return false; +} + bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, enum ovl_xattr ox) { @@ -698,6 +735,7 @@ bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, #define OVL_XATTR_IMPURE_POSTFIX "impure" #define OVL_XATTR_NLINK_POSTFIX "nlink" #define OVL_XATTR_UPPER_POSTFIX "upper" +#define OVL_XATTR_UUID_POSTFIX "uuid" #define OVL_XATTR_METACOPY_POSTFIX "metacopy" #define OVL_XATTR_PROTATTR_POSTFIX "protattr" @@ -712,6 +750,7 @@ const char *const ovl_xattr_table[][2] = { OVL_XATTR_TAB_ENTRY(OVL_XATTR_IMPURE), OVL_XATTR_TAB_ENTRY(OVL_XATTR_NLINK), OVL_XATTR_TAB_ENTRY(OVL_XATTR_UPPER), + OVL_XATTR_TAB_ENTRY(OVL_XATTR_UUID), OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY), OVL_XATTR_TAB_ENTRY(OVL_XATTR_PROTATTR), }; |