Messages in this thread | | | From | Jeff Moyer <> | Subject | Re: [PATCH] do_direct_IO: Use inode->i_blkbits to compute block count to be cleaned | Date | Mon, 09 Jan 2017 11:04:15 -0500 |
| |
Chandan Rajendra <chandan@linux.vnet.ibm.com> writes:
> 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 <chandan@linux.vnet.ibm.com> > --- > 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 aeae8c0..b20adf9 100644 > --- a/fs/direct-io.c > +++ b/fs/direct-io.c > @@ -905,6 +905,7 @@ static inline void dio_zero_block(struct dio *dio, struct dio_submit *sdio, > static int do_direct_IO(struct dio *dio, struct dio_submit *sdio, > struct buffer_head *map_bh) > { > + const unsigned i_blkbits = dio->inode->i_blkbits;
NAK. Please see commit ab73857e354 ("direct-io: don't read inode->i_blkbits multiple times").
I think you want:
const unsigned i_blkbits = sdio->blkbits + sdio->blkfactor;
as is used elsewhere in the code.
Cheers, Jeff
| |