linux-user: Implement FS_IOC_GETFLAGS and FS_IOC_SETFLAGS ioctls

Implement the FS_IOC_GETFLAGS and FS_IOC_SETFLAGS ioctls, as used
by chattr.

Note that the type information encoded in these ioctl numbers
is at odds with the actual type the kernel accesses, as discussed
in http://thread.gmane.org/gmane.linux.file-systems/80164.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

linux-user/ioctls.h

@@ -120,6 +120,9 @@
                    MK_PTR(MK_STRUCT(STRUCT_fiemap)))
 #endif
 
+     IOCTL(FS_IOC_GETFLAGS, IOC_R, MK_PTR(TYPE_INT))
+     IOCTL(FS_IOC_SETFLAGS, IOC_W, MK_PTR(TYPE_INT))
+
   IOCTL(SIOCATMARK, IOC_R, MK_PTR(TYPE_INT))
   IOCTL(SIOCGIFNAME, IOC_RW, MK_PTR(TYPE_INT))
   IOCTL(SIOCGIFFLAGS, IOC_W | IOC_R, MK_PTR(MK_STRUCT(STRUCT_short_ifreq)))

linux-user/syscall_defs.h

@@ -998,6 +998,12 @@ struct target_pollfd {
 
 #define TARGET_FIBMAP     TARGET_IO(0x00,1)  /* bmap access */
 #define TARGET_FIGETBSZ   TARGET_IO(0x00,2)  /* get the block size used for bmap */
+/* Note that the ioctl numbers claim type "long" but the actual type
+ * used by the kernel is "int".
+ */
+#define TARGET_FS_IOC_GETFLAGS TARGET_IOR('f', 1, long)
+#define TARGET_FS_IOC_SETFLAGS TARGET_IOW('f', 2, long)
+
 #define TARGET_FS_IOC_FIEMAP TARGET_IOWR('f',11,struct fiemap)
 
 /* cdrom commands */