Commit eaf5fe2d authored May 07, 2015 by Paolo Bonzini Committed by Stefan Hajnoczi May 22, 2015

block: return EPERM on writes or discards to read-only devices



This is the behavior in the operating system, for example Linux's
blkdev_write_iter has the following:

        if (bdev_read_only(I_BDEV(bd_inode)))
                return -EPERM;

This does not apply to opening a device for read/write, when the
device only supports read-only operation.  In this case any of
EACCES, EPERM or EROFS is acceptable depending on why writing is
not possible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1431013548-22492-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

parent fd0e6053

block/io.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1205,7 +1205,7 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
		return -ENOMEDIUM;
		}
		if (bs->read_only) {
		return -EACCES;
		return -EPERM;
		}

		ret = bdrv_check_byte_request(bs, offset, bytes);
		@@ -2340,7 +2340,7 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
		if (ret < 0) {
		return ret;
		} else if (bs->read_only) {
		return -EROFS;
		return -EPERM;
		}

		bdrv_reset_dirty(bs, sector_num, nb_sectors);