diff mbox

[v2,13/26] raid5: use bio_reset()

Message ID 1347322957-25260-14-git-send-email-koverstreet@google.com (mailing list archive)
State Deferred, archived
Headers show

Commit Message

Kent Overstreet Sept. 11, 2012, 12:22 a.m. UTC 
Had to shuffle the code around a bit (where bi_rw and bi_end_io were
set), but shouldn't really be anything tricky here

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
---
 drivers/md/raid5.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

Comments

NeilBrown Sept. 11, 2012, 5:03 a.m. UTC | #1 
On Mon, 10 Sep 2012 17:22:24 -0700 Kent Overstreet <koverstreet@google.com>
wrote:

> Had to shuffle the code around a bit (where bi_rw and bi_end_io were
> set), but shouldn't really be anything tricky here
> 
> Signed-off-by: Kent Overstreet <koverstreet@google.com>
> CC: Jens Axboe <axboe@kernel.dk>
> CC: NeilBrown <neilb@suse.de>
> ---
>  drivers/md/raid5.c | 28 ++++++++++++++--------------
>  1 file changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index 7c19dbe..ebe43f7 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -561,14 +561,6 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
>  		bi = &sh->dev[i].req;
>  		rbi = &sh->dev[i].rreq; /* For writing to replacement */
>  
> -		bi->bi_rw = rw;
> -		rbi->bi_rw = rw;
> -		if (rw & WRITE) {
> -			bi->bi_end_io = raid5_end_write_request;
> -			rbi->bi_end_io = raid5_end_write_request;
> -		} else
> -			bi->bi_end_io = raid5_end_read_request;
> -
>  		rcu_read_lock();
>  		rrdev = rcu_dereference(conf->disks[i].replacement);
>  		smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
> @@ -643,7 +635,14 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
>  
>  			set_bit(STRIPE_IO_STARTED, &sh->state);
>  
> +			bio_reset(bi);
>  			bi->bi_bdev = rdev->bdev;
> +			bi->bi_rw = rw;
> +			bi->bi_end_io = (rw & WRITE)
> +				? raid5_end_write_request
> +				: raid5_end_read_request;
> +			bi->bi_private = sh;
> +
>  			pr_debug("%s: for %llu schedule op %ld on disc %d\n",
>  				__func__, (unsigned long long)sh->sector,
>  				bi->bi_rw, i);
> @@ -657,12 +656,9 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
>  			if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
>  				bi->bi_rw |= REQ_FLUSH;
>  
> -			bi->bi_flags = 1 << BIO_UPTODATE;
> -			bi->bi_idx = 0;
>  			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
>  			bi->bi_io_vec[0].bv_offset = 0;
>  			bi->bi_size = STRIPE_SIZE;
> -			bi->bi_next = NULL;
>  			if (rrdev)
>  				set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
>  			generic_make_request(bi);
> @@ -674,7 +670,14 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
>  
>  			set_bit(STRIPE_IO_STARTED, &sh->state);
>  
> +			bio_reset(rbi);
>  			rbi->bi_bdev = rrdev->bdev;
> +			rbi->bi_rw = rw;
> +			rbi->bi_end_io = (rw & WRITE)
> +				? raid5_end_write_request
> +				: raid5_end_read_request;

'rbi->bi_end_io' can only ever be raid5_end_write_request.  We only get here
on a write.
I'd be OK with 
    BUG_ON(!(rw & WRITE));
but I don't want the condition in the assignment.

The rest looks quite sane.

Thanks
NeilBrown
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Kent Overstreet Sept. 11, 2012, 7:26 p.m. UTC | #2 
On Tue, Sep 11, 2012 at 03:03:26PM +1000, NeilBrown wrote:
> On Mon, 10 Sep 2012 17:22:24 -0700 Kent Overstreet <koverstreet@google.com>
> wrote:
> 
> > Had to shuffle the code around a bit (where bi_rw and bi_end_io were
> > set), but shouldn't really be anything tricky here
> > 
> > Signed-off-by: Kent Overstreet <koverstreet@google.com>
> > CC: Jens Axboe <axboe@kernel.dk>
> > CC: NeilBrown <neilb@suse.de>
> > ---
> >  drivers/md/raid5.c | 28 ++++++++++++++--------------
> >  1 file changed, 14 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> > index 7c19dbe..ebe43f7 100644
> > --- a/drivers/md/raid5.c
> > +++ b/drivers/md/raid5.c
> > @@ -561,14 +561,6 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
> >  		bi = &sh->dev[i].req;
> >  		rbi = &sh->dev[i].rreq; /* For writing to replacement */
> >  
> > -		bi->bi_rw = rw;
> > -		rbi->bi_rw = rw;
> > -		if (rw & WRITE) {
> > -			bi->bi_end_io = raid5_end_write_request;
> > -			rbi->bi_end_io = raid5_end_write_request;
> > -		} else
> > -			bi->bi_end_io = raid5_end_read_request;
> > -
> >  		rcu_read_lock();
> >  		rrdev = rcu_dereference(conf->disks[i].replacement);
> >  		smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
> > @@ -643,7 +635,14 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
> >  
> >  			set_bit(STRIPE_IO_STARTED, &sh->state);
> >  
> > +			bio_reset(bi);
> >  			bi->bi_bdev = rdev->bdev;
> > +			bi->bi_rw = rw;
> > +			bi->bi_end_io = (rw & WRITE)
> > +				? raid5_end_write_request
> > +				: raid5_end_read_request;
> > +			bi->bi_private = sh;
> > +
> >  			pr_debug("%s: for %llu schedule op %ld on disc %d\n",
> >  				__func__, (unsigned long long)sh->sector,
> >  				bi->bi_rw, i);
> > @@ -657,12 +656,9 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
> >  			if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
> >  				bi->bi_rw |= REQ_FLUSH;
> >  
> > -			bi->bi_flags = 1 << BIO_UPTODATE;
> > -			bi->bi_idx = 0;
> >  			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> >  			bi->bi_io_vec[0].bv_offset = 0;
> >  			bi->bi_size = STRIPE_SIZE;
> > -			bi->bi_next = NULL;
> >  			if (rrdev)
> >  				set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
> >  			generic_make_request(bi);
> > @@ -674,7 +670,14 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
> >  
> >  			set_bit(STRIPE_IO_STARTED, &sh->state);
> >  
> > +			bio_reset(rbi);
> >  			rbi->bi_bdev = rrdev->bdev;
> > +			rbi->bi_rw = rw;
> > +			rbi->bi_end_io = (rw & WRITE)
> > +				? raid5_end_write_request
> > +				: raid5_end_read_request;
> 
> 'rbi->bi_end_io' can only ever be raid5_end_write_request.  We only get here
> on a write.
> I'd be OK with 
>     BUG_ON(!(rw & WRITE));
> but I don't want the condition in the assignment.

I was thinking to myself that if I was doing a bit more with that code,
I'd factor out all the code in the if (rdev) {} into a separate function
that was called twice there. But, I didn't do that here so you're right
- I'll change it and stick a BUG_ON() there.

> The rest looks quite sane.

Thanks!

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diff mbox

Patch

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 7c19dbe..ebe43f7 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -561,14 +561,6 @@  static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 		bi = &sh->dev[i].req;
 		rbi = &sh->dev[i].rreq; /* For writing to replacement */
 
-		bi->bi_rw = rw;
-		rbi->bi_rw = rw;
-		if (rw & WRITE) {
-			bi->bi_end_io = raid5_end_write_request;
-			rbi->bi_end_io = raid5_end_write_request;
-		} else
-			bi->bi_end_io = raid5_end_read_request;
-
 		rcu_read_lock();
 		rrdev = rcu_dereference(conf->disks[i].replacement);
 		smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
@@ -643,7 +635,14 @@  static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 
 			set_bit(STRIPE_IO_STARTED, &sh->state);
 
+			bio_reset(bi);
 			bi->bi_bdev = rdev->bdev;
+			bi->bi_rw = rw;
+			bi->bi_end_io = (rw & WRITE)
+				? raid5_end_write_request
+				: raid5_end_read_request;
+			bi->bi_private = sh;
+
 			pr_debug("%s: for %llu schedule op %ld on disc %d\n",
 				__func__, (unsigned long long)sh->sector,
 				bi->bi_rw, i);
@@ -657,12 +656,9 @@  static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 			if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
 				bi->bi_rw |= REQ_FLUSH;
 
-			bi->bi_flags = 1 << BIO_UPTODATE;
-			bi->bi_idx = 0;
 			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			bi->bi_io_vec[0].bv_offset = 0;
 			bi->bi_size = STRIPE_SIZE;
-			bi->bi_next = NULL;
 			if (rrdev)
 				set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
 			generic_make_request(bi);
@@ -674,7 +670,14 @@  static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 
 			set_bit(STRIPE_IO_STARTED, &sh->state);
 
+			bio_reset(rbi);
 			rbi->bi_bdev = rrdev->bdev;
+			rbi->bi_rw = rw;
+			rbi->bi_end_io = (rw & WRITE)
+				? raid5_end_write_request
+				: raid5_end_read_request;
+			rbi->bi_private = sh;
+
 			pr_debug("%s: for %llu schedule op %ld on "
 				 "replacement disc %d\n",
 				__func__, (unsigned long long)sh->sector,
@@ -686,12 +689,9 @@  static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 			else
 				rbi->bi_sector = (sh->sector
 						  + rrdev->data_offset);
-			rbi->bi_flags = 1 << BIO_UPTODATE;
-			rbi->bi_idx = 0;
 			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			rbi->bi_io_vec[0].bv_offset = 0;
 			rbi->bi_size = STRIPE_SIZE;
-			rbi->bi_next = NULL;
 			generic_make_request(rbi);
 		}
 		if (!rdev && !rrdev) {