Block drivers and DM sometimes use EROFS to report errors. There is no confusion about what happens but naive error reporting code might pass -EROFS to strerror(3) which will print "filesystem" when clearly there is no filesystem anywhere, it is layer above. Or in other words, if EROFS exists, why not EROBLK? It is not like there is a tax on errno values. Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> --- include/uapi/asm-generic/errno.h | 1 + 1 file changed, 1 insertion(+) --- a/include/uapi/asm-generic/errno.h +++ b/include/uapi/asm-generic/errno.h @@ -119,5 +119,6 @@ #define ERFKILL 132 /* Operation not possible due to RF-kill */ #define EHWPOISON 133 /* Memory page has hardware error */ +#define EROBLK 134 /* Block device is read-only */ #endif