On Thu, Mar 01, 2012 at 11:41:03PM +0530, Saugata Das wrote: > From: Saugata Das <saugata.das@xxxxxxxxxx> > > Today, storage devices like eMMC has special features like data tagging > (introduced in MMC-4.5 version) in order to improve performance of some > specific writes. On MMC stack, data tagging is used for all writes which has > REQ_META flag set. On EXT4, however, currently REQ_META is set only for read. > This patch adds the capability to add REQ_META flag during meta data write. > This patch adds new function set_buffer_meta, which is used to set a bit > BH_Meta in the b_state field when meta data and super block is made dirty. > > --- a/fs/buffer.c > +++ b/fs/buffer.c > @@ -2926,6 +2926,9 @@ int submit_bh(int rw, struct buffer_head * bh) > if (test_set_buffer_req(bh) && (rw & WRITE)) > clear_buffer_write_io_error(bh); > > + if (buffer_meta(bh) && (rw & WRITE)) > + rw |= REQ_META; > + I know it's not necessary for your purposes as stated in the commit description, but wouldn't it be better if buffer_meta() always caused REQ_META to be set, regardless of whether we are doing a read or a write? - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
