block: move discard checks into the ioctl handler

[linux-block.git] / block / ioctl.c

diff --git a/block/ioctl.c b/block/ioctl.c
index 06ff3023e2a133c3fb4449b6971286939b9ebf48..49fa02b17ec14608e28405fd5c079b25712b3088 100644 (file)
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -95,6 +95,7 @@ static int compat_blkpg_ioctl(struct block_device *bdev,
 static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
                unsigned long arg)
 {
+       unsigned int bs_mask = bdev_logical_block_size(bdev) - 1;
        uint64_t range[2];
        uint64_t start, len;
        struct inode *inode = bdev->bd_inode;
@@ -105,6 +106,8 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
 
        if (!bdev_max_discard_sectors(bdev))
                return -EOPNOTSUPP;
+       if (bdev_read_only(bdev))
+               return -EPERM;
 
        if (copy_from_user(range, (void __user *)arg, sizeof(range)))
                return -EFAULT;
@@ -112,9 +115,9 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
        start = range[0];
        len = range[1];
 
-       if (start & 511)
+       if (!len)
                return -EINVAL;
-       if (len & 511)
+       if ((start | len) & bs_mask)
                return -EINVAL;
 
        if (start + len > bdev_nr_bytes(bdev))