commit bbab37ddc20b (block: Add support for DAX reads/writes to block devices) caused a regression in mkfs.xfs. That utility sets the block size of the device to the logical block size using the BLKBSZSET ioctl, and then issues a single sector read from the last sector of the device. This results in the dax_io code trying to do a page-sized read from 512 bytes from the end of the device. The result is -ERANGE being returned to userspace.
The fix is to align the block to the page size before calling get_block. Thanks to willy for simplifying my original patch. Signed-off-by: Jeff Moyer <[email protected]> --- fs/dax.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/dax.c b/fs/dax.c index a7f77e1..ef35a20 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -116,7 +116,8 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, unsigned len; if (pos == max) { unsigned blkbits = inode->i_blkbits; - sector_t block = pos >> blkbits; + long page = pos >> PAGE_SHIFT; + sector_t block = page << (PAGE_SHIFT - blkbits); unsigned first = pos - (block << blkbits); long size; -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
