Similar to blkdev_write_iter(), return -EPERM if the partition is
read-only.  This covers ioctl(), fallocate() and most in-kernel users
but isn't meant to be exhaustive -- everything else will be caught in
generic_make_request_checks(), fail with -EIO and can be fixed later.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
        if (!q)
                return -ENXIO;
 
+       if (bdev_read_only(bdev))
+               return -EPERM;
+
        if (flags & BLKDEV_DISCARD_SECURE) {
                if (!blk_queue_secure_erase(q))
                        return -EOPNOTSUPP;
        if (!q)
                return -ENXIO;
 
+       if (bdev_read_only(bdev))
+               return -EPERM;
+
        bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
        if ((sector | nr_sects) & bs_mask)
                return -EINVAL;
        if (!q)
                return -ENXIO;
 
+       if (bdev_read_only(bdev))
+               return -EPERM;
+
        /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
        max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
 
        if (!q)
                return -ENXIO;
 
+       if (bdev_read_only(bdev))
+               return -EPERM;
+
        while (nr_sects != 0) {
                bio = next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
                               gfp_mask);