[PATCH] md: Partially revert 2f6db2a7, which broke raid5

[PATCH] md: Partially revert 2f6db2a7, which broke raid5

[Calvin Owens]

Commit 2f6db2a7 was part of a series that cleaned up mdraid code by
replacing explicit re-initialization of struct bio with bio_reset().

In raid5 it incorrectly assumed that a couple initializations of its
members was a full reset, erasing the existing data and unconditionally
triggering the following BUG when assembling arrays:

[   14.653072] kernel BUG at /home/calvinow/git/linux/drivers/scsi/scsi_lib.c:1196!
[   14.653074] invalid opcode: 0000 [#1] PREEMPT SMP
[   14.653076] CPU: 1 PID: 40 Comm: kworker/1:0H Not tainted 3.10.0-rc1-amd-00279-g8f710dd #3
[   14.653077] Hardware name: System manufacturer System Product Name/M5A88-M, BIOS 0601    09/20/2011
[   14.653082] Workqueue: kblockd blk_delay_work
<snip>
[   14.653123] Call Trace:
[   14.653126]  [<ffffffff81477248>] sd_prep_fn+0x2c8/0xb70
[   14.653129]  [<ffffffff812c8b70>] ? deadline_remove_request.isra.9+0x50/0x90
[   14.653132]  [<ffffffff812b8f5b>] blk_peek_request+0xdb/0x210
[   14.653134]  [<ffffffff81465f15>] scsi_request_fn+0x45/0x4e0
[   14.653136]  [<ffffffff812b6a51>] __blk_run_queue+0x31/0x40
[   14.653138]  [<ffffffff812b6a84>] blk_delay_work+0x24/0x40
[   14.653141]  [<ffffffff8105dc2a>] process_one_work+0x1da/0x490
[   14.653143]  [<ffffffff8105dbcd>] ? process_one_work+0x17d/0x490
[   14.653145]  [<ffffffff8105e32a>] worker_thread+0x11a/0x370
[   14.653147]  [<ffffffff8105e210>] ? rescuer_thread+0x2f0/0x2f0
[   14.653149]  [<ffffffff81066296>] kthread+0xd6/0xe0
[   14.653151]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
[   14.653154]  [<ffffffff816e4d6c>] ret_from_fork+0x7c/0xb0
[   14.653156]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
[   14.653172] Code: <snip>
[   14.653174] RIP  [<ffffffff81467329>] scsi_setup_fs_cmnd+0x89/0x90

Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>
---
 drivers/md/raid5.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 9359828..97be03f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -643,7 +643,6 @@ 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)
@@ -664,9 +663,12 @@ 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);
 
@@ -683,7 +685,6 @@ 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;
 			BUG_ON(!(rw & WRITE));
-- 
1.8.2.1

Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5

[Jens Axboe]

On Fri, May 17 2013, Calvin Owens wrote:
> Commit 2f6db2a7 was part of a series that cleaned up mdraid code by
> replacing explicit re-initialization of struct bio with bio_reset().
> 
> In raid5 it incorrectly assumed that a couple initializations of its
> members was a full reset, erasing the existing data and unconditionally
> triggering the following BUG when assembling arrays:
> 
> [   14.653072] kernel BUG at /home/calvinow/git/linux/drivers/scsi/scsi_lib.c:1196!
> [   14.653074] invalid opcode: 0000 [#1] PREEMPT SMP
> [   14.653076] CPU: 1 PID: 40 Comm: kworker/1:0H Not tainted 3.10.0-rc1-amd-00279-g8f710dd #3
> [   14.653077] Hardware name: System manufacturer System Product Name/M5A88-M, BIOS 0601    09/20/2011
> [   14.653082] Workqueue: kblockd blk_delay_work
> <snip>
> [   14.653123] Call Trace:
> [   14.653126]  [<ffffffff81477248>] sd_prep_fn+0x2c8/0xb70
> [   14.653129]  [<ffffffff812c8b70>] ? deadline_remove_request.isra.9+0x50/0x90
> [   14.653132]  [<ffffffff812b8f5b>] blk_peek_request+0xdb/0x210
> [   14.653134]  [<ffffffff81465f15>] scsi_request_fn+0x45/0x4e0
> [   14.653136]  [<ffffffff812b6a51>] __blk_run_queue+0x31/0x40
> [   14.653138]  [<ffffffff812b6a84>] blk_delay_work+0x24/0x40
> [   14.653141]  [<ffffffff8105dc2a>] process_one_work+0x1da/0x490
> [   14.653143]  [<ffffffff8105dbcd>] ? process_one_work+0x17d/0x490
> [   14.653145]  [<ffffffff8105e32a>] worker_thread+0x11a/0x370
> [   14.653147]  [<ffffffff8105e210>] ? rescuer_thread+0x2f0/0x2f0
> [   14.653149]  [<ffffffff81066296>] kthread+0xd6/0xe0
> [   14.653151]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
> [   14.653154]  [<ffffffff816e4d6c>] ret_from_fork+0x7c/0xb0
> [   14.653156]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
> [   14.653172] Code: <snip>
> [   14.653174] RIP  [<ffffffff81467329>] scsi_setup_fs_cmnd+0x89/0x90
> 
> Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>

Kent, there was a report on this issue yesterday as well. We need to get
this fixed up ASAP.

-- 
Jens Axboe

Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5

[Kent Overstreet]

On Sat, May 18, 2013 at 09:05:15AM +0200, Jens Axboe wrote:
> On Fri, May 17 2013, Calvin Owens wrote:
> > Commit 2f6db2a7 was part of a series that cleaned up mdraid code by
> > replacing explicit re-initialization of struct bio with bio_reset().
> > 
> > In raid5 it incorrectly assumed that a couple initializations of its
> > members was a full reset, erasing the existing data and unconditionally
> > triggering the following BUG when assembling arrays:
> > 
> > [   14.653072] kernel BUG at /home/calvinow/git/linux/drivers/scsi/scsi_lib.c:1196!
> > [   14.653074] invalid opcode: 0000 [#1] PREEMPT SMP
> > [   14.653076] CPU: 1 PID: 40 Comm: kworker/1:0H Not tainted 3.10.0-rc1-amd-00279-g8f710dd #3
> > [   14.653077] Hardware name: System manufacturer System Product Name/M5A88-M, BIOS 0601    09/20/2011
> > [   14.653082] Workqueue: kblockd blk_delay_work
> > <snip>
> > [   14.653123] Call Trace:
> > [   14.653126]  [<ffffffff81477248>] sd_prep_fn+0x2c8/0xb70
> > [   14.653129]  [<ffffffff812c8b70>] ? deadline_remove_request.isra.9+0x50/0x90
> > [   14.653132]  [<ffffffff812b8f5b>] blk_peek_request+0xdb/0x210
> > [   14.653134]  [<ffffffff81465f15>] scsi_request_fn+0x45/0x4e0
> > [   14.653136]  [<ffffffff812b6a51>] __blk_run_queue+0x31/0x40
> > [   14.653138]  [<ffffffff812b6a84>] blk_delay_work+0x24/0x40
> > [   14.653141]  [<ffffffff8105dc2a>] process_one_work+0x1da/0x490
> > [   14.653143]  [<ffffffff8105dbcd>] ? process_one_work+0x17d/0x490
> > [   14.653145]  [<ffffffff8105e32a>] worker_thread+0x11a/0x370
> > [   14.653147]  [<ffffffff8105e210>] ? rescuer_thread+0x2f0/0x2f0
> > [   14.653149]  [<ffffffff81066296>] kthread+0xd6/0xe0
> > [   14.653151]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
> > [   14.653154]  [<ffffffff816e4d6c>] ret_from_fork+0x7c/0xb0
> > [   14.653156]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
> > [   14.653172] Code: <snip>
> > [   14.653174] RIP  [<ffffffff81467329>] scsi_setup_fs_cmnd+0x89/0x90
> > 
> > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>
> 
> Kent, there was a report on this issue yesterday as well. We need to get
> this fixed up ASAP.

Sorry for the delay - been vacationing. Reproduced the original bug,
here's a patch that fixes it:


commit 402f5db3708b2062795a384a3d8397cf702e27bc
Author: Kent Overstreet <koverstreet@google.com>
Date:   Sun May 19 10:27:07 2013 -0700

    raid5: Initialize bi_vcnt
    
    The patch that converted raid5 to use bio_reset() forgot to initialize
    bi_vcnt.
    
    Signed-off-by: Kent Overstreet <koverstreet@google.com>
    Cc: NeilBrown <neilb@suse.de>
    Cc: Jens Axboe <axboe@kernel.dk>
    Cc: linux-raid@vger.kernel.org

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 9359828..753f318 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -664,6 +664,7 @@ 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_vcnt = 1;
 			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			bi->bi_io_vec[0].bv_offset = 0;
 			bi->bi_size = STRIPE_SIZE;
@@ -701,6 +702,7 @@ 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_vcnt = 1;
 			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			rbi->bi_io_vec[0].bv_offset = 0;
 			rbi->bi_size = STRIPE_SIZE;

Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5

[Ilia Mirkin]

On Sun, May 19, 2013 at 1:51 PM, Kent Overstreet <koverstreet@google.com> wrote:
> On Sat, May 18, 2013 at 09:05:15AM +0200, Jens Axboe wrote:
>> On Fri, May 17 2013, Calvin Owens wrote:
>> > Commit 2f6db2a7 was part of a series that cleaned up mdraid code by
>> > replacing explicit re-initialization of struct bio with bio_reset().
>> >
>> > In raid5 it incorrectly assumed that a couple initializations of its
>> > members was a full reset, erasing the existing data and unconditionally
>> > triggering the following BUG when assembling arrays:
>> >
>> > [   14.653072] kernel BUG at /home/calvinow/git/linux/drivers/scsi/scsi_lib.c:1196!
>> > [   14.653074] invalid opcode: 0000 [#1] PREEMPT SMP
>> > [   14.653076] CPU: 1 PID: 40 Comm: kworker/1:0H Not tainted 3.10.0-rc1-amd-00279-g8f710dd #3
>> > [   14.653077] Hardware name: System manufacturer System Product Name/M5A88-M, BIOS 0601    09/20/2011
>> > [   14.653082] Workqueue: kblockd blk_delay_work
>> > <snip>
>> > [   14.653123] Call Trace:
>> > [   14.653126]  [<ffffffff81477248>] sd_prep_fn+0x2c8/0xb70
>> > [   14.653129]  [<ffffffff812c8b70>] ? deadline_remove_request.isra.9+0x50/0x90
>> > [   14.653132]  [<ffffffff812b8f5b>] blk_peek_request+0xdb/0x210
>> > [   14.653134]  [<ffffffff81465f15>] scsi_request_fn+0x45/0x4e0
>> > [   14.653136]  [<ffffffff812b6a51>] __blk_run_queue+0x31/0x40
>> > [   14.653138]  [<ffffffff812b6a84>] blk_delay_work+0x24/0x40
>> > [   14.653141]  [<ffffffff8105dc2a>] process_one_work+0x1da/0x490
>> > [   14.653143]  [<ffffffff8105dbcd>] ? process_one_work+0x17d/0x490
>> > [   14.653145]  [<ffffffff8105e32a>] worker_thread+0x11a/0x370
>> > [   14.653147]  [<ffffffff8105e210>] ? rescuer_thread+0x2f0/0x2f0
>> > [   14.653149]  [<ffffffff81066296>] kthread+0xd6/0xe0
>> > [   14.653151]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
>> > [   14.653154]  [<ffffffff816e4d6c>] ret_from_fork+0x7c/0xb0
>> > [   14.653156]  [<ffffffff810661c0>] ? __kthread_unpark+0x50/0x50
>> > [   14.653172] Code: <snip>
>> > [   14.653174] RIP  [<ffffffff81467329>] scsi_setup_fs_cmnd+0x89/0x90
>> >
>> > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com>
>>
>> Kent, there was a report on this issue yesterday as well. We need to get
>> this fixed up ASAP.
>
> Sorry for the delay - been vacationing. Reproduced the original bug,
> here's a patch that fixes it:

I saw this issue as well, and your patch fixes it for me (feel free to
add my Tested-By if necessary). It didn't appear to be in v3.10-rc3,
or any relevant git repos I could find -- just want to make sure it
didn't get lost somewhere down the line, since otherwise my system
dies.

>
>
> commit 402f5db3708b2062795a384a3d8397cf702e27bc
> Author: Kent Overstreet <koverstreet@google.com>
> Date:   Sun May 19 10:27:07 2013 -0700
>
>     raid5: Initialize bi_vcnt
>
>     The patch that converted raid5 to use bio_reset() forgot to initialize
>     bi_vcnt.
>
>     Signed-off-by: Kent Overstreet <koverstreet@google.com>
>     Cc: NeilBrown <neilb@suse.de>
>     Cc: Jens Axboe <axboe@kernel.dk>
>     Cc: linux-raid@vger.kernel.org
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index 9359828..753f318 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -664,6 +664,7 @@ 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_vcnt = 1;
>                         bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
>                         bi->bi_io_vec[0].bv_offset = 0;
>                         bi->bi_size = STRIPE_SIZE;
> @@ -701,6 +702,7 @@ 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_vcnt = 1;
>                         rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
>                         rbi->bi_io_vec[0].bv_offset = 0;
>                         rbi->bi_size = STRIPE_SIZE;
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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> Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5

[Richard W.M. Jones]

On Sun, May 19, 2013 at 10:51:45AM -0700, Kent Overstreet wrote:
> Sorry for the delay - been vacationing. Reproduced the original bug,
> here's a patch that fixes it:
> 
> 
> commit 402f5db3708b2062795a384a3d8397cf702e27bc
> Author: Kent Overstreet <koverstreet@google.com>
> Date:   Sun May 19 10:27:07 2013 -0700
> 
>     raid5: Initialize bi_vcnt
>     
>     The patch that converted raid5 to use bio_reset() forgot to initialize
>     bi_vcnt.
>     
>     Signed-off-by: Kent Overstreet <koverstreet@google.com>
>     Cc: NeilBrown <neilb@suse.de>
>     Cc: Jens Axboe <axboe@kernel.dk>
>     Cc: linux-raid@vger.kernel.org
> 
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index 9359828..753f318 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -664,6 +664,7 @@ 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_vcnt = 1;
>  			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
>  			bi->bi_io_vec[0].bv_offset = 0;
>  			bi->bi_size = STRIPE_SIZE;
> @@ -701,6 +702,7 @@ 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_vcnt = 1;
>  			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
>  			rbi->bi_io_vec[0].bv_offset = 0;
>  			rbi->bi_size = STRIPE_SIZE;

Ditto to the previous follow up.  We've been tracking this
bug for nearly a month:

https://bugzilla.redhat.com/show_bug.cgi?id=962079

Please include this (or the other) patch to fix it.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top

Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5

[Jens Axboe]

On Wed, May 29 2013, Richard W.M. Jones wrote:
> 
> On Sun, May 19, 2013 at 10:51:45AM -0700, Kent Overstreet wrote:
> > Sorry for the delay - been vacationing. Reproduced the original bug,
> > here's a patch that fixes it:
> > 
> > 
> > commit 402f5db3708b2062795a384a3d8397cf702e27bc
> > Author: Kent Overstreet <koverstreet@google.com>
> > Date:   Sun May 19 10:27:07 2013 -0700
> > 
> >     raid5: Initialize bi_vcnt
> >     
> >     The patch that converted raid5 to use bio_reset() forgot to initialize
> >     bi_vcnt.
> >     
> >     Signed-off-by: Kent Overstreet <koverstreet@google.com>
> >     Cc: NeilBrown <neilb@suse.de>
> >     Cc: Jens Axboe <axboe@kernel.dk>
> >     Cc: linux-raid@vger.kernel.org
> > 
> > diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> > index 9359828..753f318 100644
> > --- a/drivers/md/raid5.c
> > +++ b/drivers/md/raid5.c
> > @@ -664,6 +664,7 @@ 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_vcnt = 1;
> >  			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> >  			bi->bi_io_vec[0].bv_offset = 0;
> >  			bi->bi_size = STRIPE_SIZE;
> > @@ -701,6 +702,7 @@ 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_vcnt = 1;
> >  			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> >  			rbi->bi_io_vec[0].bv_offset = 0;
> >  			rbi->bi_size = STRIPE_SIZE;
> 
> Ditto to the previous follow up.  We've been tracking this
> bug for nearly a month:
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=962079
> 
> Please include this (or the other) patch to fix it.

I'm assuming both Kent and I are waiting for Neil to pick it up. Neil, I
can include this in my next round going upstream, just let me know. It
should have been sent upstream a while back, sorry guys.

-- 
Jens Axboe

Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 2325 bytes --]

On Wed, 29 May 2013 15:03:40 +0200 Jens Axboe <axboe@kernel.dk> wrote:

> On Wed, May 29 2013, Richard W.M. Jones wrote:
> > 
> > On Sun, May 19, 2013 at 10:51:45AM -0700, Kent Overstreet wrote:
> > > Sorry for the delay - been vacationing. Reproduced the original bug,
> > > here's a patch that fixes it:
> > > 
> > > 
> > > commit 402f5db3708b2062795a384a3d8397cf702e27bc
> > > Author: Kent Overstreet <koverstreet@google.com>
> > > Date:   Sun May 19 10:27:07 2013 -0700
> > > 
> > >     raid5: Initialize bi_vcnt
> > >     
> > >     The patch that converted raid5 to use bio_reset() forgot to initialize
> > >     bi_vcnt.
> > >     
> > >     Signed-off-by: Kent Overstreet <koverstreet@google.com>
> > >     Cc: NeilBrown <neilb@suse.de>
> > >     Cc: Jens Axboe <axboe@kernel.dk>
> > >     Cc: linux-raid@vger.kernel.org
> > > 
> > > diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> > > index 9359828..753f318 100644
> > > --- a/drivers/md/raid5.c
> > > +++ b/drivers/md/raid5.c
> > > @@ -664,6 +664,7 @@ 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_vcnt = 1;
> > >  			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> > >  			bi->bi_io_vec[0].bv_offset = 0;
> > >  			bi->bi_size = STRIPE_SIZE;
> > > @@ -701,6 +702,7 @@ 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_vcnt = 1;
> > >  			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> > >  			rbi->bi_io_vec[0].bv_offset = 0;
> > >  			rbi->bi_size = STRIPE_SIZE;
> > 
> > Ditto to the previous follow up.  We've been tracking this
> > bug for nearly a month:
> > 
> > https://bugzilla.redhat.com/show_bug.cgi?id=962079
> > 
> > Please include this (or the other) patch to fix it.
> 
> I'm assuming both Kent and I are waiting for Neil to pick it up. Neil, I
> can include this in my next round going upstream, just let me know. It
> should have been sent upstream a while back, sorry guys.
> 

Seems you were waiting for me, and I was waiting for you :-)

Yes: please include it with your next round.  Thanks!

NeilBrown

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Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5

[Jens Axboe]

On Thu, May 30 2013, NeilBrown wrote:
> On Wed, 29 May 2013 15:03:40 +0200 Jens Axboe <axboe@kernel.dk> wrote:
> 
> > On Wed, May 29 2013, Richard W.M. Jones wrote:
> > > 
> > > On Sun, May 19, 2013 at 10:51:45AM -0700, Kent Overstreet wrote:
> > > > Sorry for the delay - been vacationing. Reproduced the original bug,
> > > > here's a patch that fixes it:
> > > > 
> > > > 
> > > > commit 402f5db3708b2062795a384a3d8397cf702e27bc
> > > > Author: Kent Overstreet <koverstreet@google.com>
> > > > Date:   Sun May 19 10:27:07 2013 -0700
> > > > 
> > > >     raid5: Initialize bi_vcnt
> > > >     
> > > >     The patch that converted raid5 to use bio_reset() forgot to initialize
> > > >     bi_vcnt.
> > > >     
> > > >     Signed-off-by: Kent Overstreet <koverstreet@google.com>
> > > >     Cc: NeilBrown <neilb@suse.de>
> > > >     Cc: Jens Axboe <axboe@kernel.dk>
> > > >     Cc: linux-raid@vger.kernel.org
> > > > 
> > > > diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> > > > index 9359828..753f318 100644
> > > > --- a/drivers/md/raid5.c
> > > > +++ b/drivers/md/raid5.c
> > > > @@ -664,6 +664,7 @@ 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_vcnt = 1;
> > > >  			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> > > >  			bi->bi_io_vec[0].bv_offset = 0;
> > > >  			bi->bi_size = STRIPE_SIZE;
> > > > @@ -701,6 +702,7 @@ 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_vcnt = 1;
> > > >  			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> > > >  			rbi->bi_io_vec[0].bv_offset = 0;
> > > >  			rbi->bi_size = STRIPE_SIZE;
> > > 
> > > Ditto to the previous follow up.  We've been tracking this
> > > bug for nearly a month:
> > > 
> > > https://bugzilla.redhat.com/show_bug.cgi?id=962079
> > > 
> > > Please include this (or the other) patch to fix it.
> > 
> > I'm assuming both Kent and I are waiting for Neil to pick it up. Neil, I
> > can include this in my next round going upstream, just let me know. It
> > should have been sent upstream a while back, sorry guys.
> > 
> 
> Seems you were waiting for me, and I was waiting for you :-)
> 
> Yes: please include it with your next round.  Thanks!

Hah, in that case we could have waited for a long time! I'll add it to
the current mix, thanks.

-- 
Jens Axboe

Re: [PATCH] md: Partially revert 2f6db2a7, which broke raid5

[Richard W.M. Jones]

On Thu, May 30, 2013 at 09:22:43AM +1000, NeilBrown wrote:
> On Wed, 29 May 2013 15:03:40 +0200 Jens Axboe <axboe@kernel.dk> wrote:
> 
> > On Wed, May 29 2013, Richard W.M. Jones wrote:
> > > 
> > > On Sun, May 19, 2013 at 10:51:45AM -0700, Kent Overstreet wrote:
> > > > Sorry for the delay - been vacationing. Reproduced the original bug,
> > > > here's a patch that fixes it:
> > > > 
> > > > 
> > > > commit 402f5db3708b2062795a384a3d8397cf702e27bc
> > > > Author: Kent Overstreet <koverstreet@google.com>
> > > > Date:   Sun May 19 10:27:07 2013 -0700
> > > > 
> > > >     raid5: Initialize bi_vcnt
> > > >     
> > > >     The patch that converted raid5 to use bio_reset() forgot to initialize
> > > >     bi_vcnt.
> > > >     
> > > >     Signed-off-by: Kent Overstreet <koverstreet@google.com>
> > > >     Cc: NeilBrown <neilb@suse.de>
> > > >     Cc: Jens Axboe <axboe@kernel.dk>
> > > >     Cc: linux-raid@vger.kernel.org
> > > > 
> > > > diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> > > > index 9359828..753f318 100644
> > > > --- a/drivers/md/raid5.c
> > > > +++ b/drivers/md/raid5.c
> > > > @@ -664,6 +664,7 @@ 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_vcnt = 1;
> > > >  			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> > > >  			bi->bi_io_vec[0].bv_offset = 0;
> > > >  			bi->bi_size = STRIPE_SIZE;
> > > > @@ -701,6 +702,7 @@ 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_vcnt = 1;
> > > >  			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
> > > >  			rbi->bi_io_vec[0].bv_offset = 0;
> > > >  			rbi->bi_size = STRIPE_SIZE;
> > > 
> > > Ditto to the previous follow up.  We've been tracking this
> > > bug for nearly a month:
> > > 
> > > https://bugzilla.redhat.com/show_bug.cgi?id=962079
> > > 
> > > Please include this (or the other) patch to fix it.
> > 
> > I'm assuming both Kent and I are waiting for Neil to pick it up. Neil, I
> > can include this in my next round going upstream, just let me know. It
> > should have been sent upstream a while back, sorry guys.
> > 
> 
> Seems you were waiting for me, and I was waiting for you :-)
> 
> Yes: please include it with your next round.  Thanks!

BTW I tested this patch and it works, so:

Tested-by: Richard W.M. Jones <rjones@redhat.com>

Rich.

-- 
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