From dd545b52a3e1efd9f2c6352dbe95ccd0c53461cc Mon Sep 17 00:00:00 2001 From: Chandan Rajendra Date: Tue, 10 Jan 2017 13:29:54 -0700 Subject: [PATCH] do_direct_IO: Use inode->i_blkbits to compute block count to be cleaned The code currently uses sdio->blkbits to compute the number of blocks to be cleaned. However sdio->blkbits is derived from the logical block size of the underlying block device (Refer to the definition of do_blockdev_direct_IO()). Due to this, generic/299 test would rarely fail when executed on an ext4 filesystem with 64k as the block size and when using a virtio based disk (having 512 byte as the logical block size) inside a kvm guest. This commit fixes the bug by using inode->i_blkbits to compute the number of blocks to be cleaned. Signed-off-by: Chandan Rajendra Reviewed-by: Christoph Hellwig Fixed up by Jeff Moyer to only use/evaluate inode->i_blkbits once, to avoid issues with block size changes with IO in flight. Signed-off-by: Jens Axboe --- fs/direct-io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index aeae8c063451..c87bae4376b8 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -906,6 +906,7 @@ static int do_direct_IO(struct dio *dio, struct dio_submit *sdio, struct buffer_head *map_bh) { const unsigned blkbits = sdio->blkbits; + const unsigned i_blkbits = blkbits + sdio->blkfactor; int ret = 0; while (sdio->block_in_file < sdio->final_block_in_request) { @@ -949,7 +950,7 @@ static int do_direct_IO(struct dio *dio, struct dio_submit *sdio, clean_bdev_aliases( map_bh->b_bdev, map_bh->b_blocknr, - map_bh->b_size >> blkbits); + map_bh->b_size >> i_blkbits); } if (!sdio->blkfactor) -- 2.20.1