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* FAILED: patch "[PATCH] dm log writes: fix bug with too large bios" failed to apply to 4.7-stable tree
@ 2016-09-22 13:21 gregkh
  2016-09-22 20:40 ` [PATCH] dm log writes: fix bug with too large bios Mikulas Patocka
  0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2016-09-22 13:21 UTC (permalink / raw)
  To: mpatocka, jbacik, snitzer; +Cc: stable


The patch below does not apply to the 4.7-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 7efb367320f56fc4d549875b6f3a6940018ef2e5 Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Tue, 30 Aug 2016 16:20:55 -0400
Subject: [PATCH] dm log writes: fix bug with too large bios

bio_alloc() can allocate a bio with at most BIO_MAX_PAGES (256) vector
entries.  However, the incoming bio may have more vector entries if it
was allocated by other means.  For example, bcache submits bios with
more than BIO_MAX_PAGES entries.  This results in bio_alloc() failure.

To avoid the failure, change the code so that it allocates bio with at
most BIO_MAX_PAGES entries.  If the incoming bio has more entries,
bio_add_page() will fail and a new bio will be allocated - the code that
handles bio_add_page() failure already exists in the dm-log-writes
target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Josef Bacik <jbacik@fb,com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v4.1+

diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index 4cc78aef9007..ba24f4f37efc 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -260,7 +260,7 @@ static int log_one_block(struct log_writes_c *lc,
 	sector++;
 
 	atomic_inc(&lc->io_blocks);
-	bio = bio_alloc(GFP_KERNEL, block->vec_cnt);
+	bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES));
 	if (!bio) {
 		DMERR("Couldn't alloc log bio");
 		goto error;
@@ -282,7 +282,7 @@ static int log_one_block(struct log_writes_c *lc,
 		if (ret != block->vecs[i].bv_len) {
 			atomic_inc(&lc->io_blocks);
 			submit_bio(bio);
-			bio = bio_alloc(GFP_KERNEL, block->vec_cnt - i);
+			bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt - i, BIO_MAX_PAGES));
 			if (!bio) {
 				DMERR("Couldn't alloc log bio");
 				goto error;


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* [PATCH] dm log writes: fix bug with too large bios
  2016-09-22 13:21 FAILED: patch "[PATCH] dm log writes: fix bug with too large bios" failed to apply to 4.7-stable tree gregkh
@ 2016-09-22 20:40 ` Mikulas Patocka
  2016-10-05 15:38   ` Greg KH
  0 siblings, 1 reply; 3+ messages in thread
From: Mikulas Patocka @ 2016-09-22 20:40 UTC (permalink / raw)
  To: gregkh; +Cc: jbacik, snitzer, stable

Hi

This is backport of the upstream patch 
7efb367320f56fc4d549875b6f3a6940018ef2e5 for the stable kernels.



On Thu, 22 Sep 2016, gregkh@linuxfoundation.org wrote:

> 
> The patch below does not apply to the 4.7-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
> >From 7efb367320f56fc4d549875b6f3a6940018ef2e5 Mon Sep 17 00:00:00 2001
> From: Mikulas Patocka <mpatocka@redhat.com>
> Date: Tue, 30 Aug 2016 16:20:55 -0400
> Subject: [PATCH] dm log writes: fix bug with too large bios
> 
> bio_alloc() can allocate a bio with at most BIO_MAX_PAGES (256) vector
> entries.  However, the incoming bio may have more vector entries if it
> was allocated by other means.  For example, bcache submits bios with
> more than BIO_MAX_PAGES entries.  This results in bio_alloc() failure.
> 
> To avoid the failure, change the code so that it allocates bio with at
> most BIO_MAX_PAGES entries.  If the incoming bio has more entries,
> bio_add_page() will fail and a new bio will be allocated - the code that
> handles bio_add_page() failure already exists in the dm-log-writes
> target.
> 
> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
> Reviewed-by: Josef Bacik <jbacik@fb,com>
> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
> Cc: stable@vger.kernel.org # v4.1+
> 
> diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
> index 4cc78aef9007..ba24f4f37efc 100644
> --- a/drivers/md/dm-log-writes.c
> +++ b/drivers/md/dm-log-writes.c
> @@ -260,7 +260,7 @@ static int log_one_block(struct log_writes_c *lc,
>  	sector++;
>  
>  	atomic_inc(&lc->io_blocks);
> -	bio = bio_alloc(GFP_KERNEL, block->vec_cnt);
> +	bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES));
>  	if (!bio) {
>  		DMERR("Couldn't alloc log bio");
>  		goto error;
> @@ -282,7 +282,7 @@ static int log_one_block(struct log_writes_c *lc,
>  		if (ret != block->vecs[i].bv_len) {
>  			atomic_inc(&lc->io_blocks);
>  			submit_bio(bio);
> -			bio = bio_alloc(GFP_KERNEL, block->vec_cnt - i);
> +			bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt - i, BIO_MAX_PAGES));
>  			if (!bio) {
>  				DMERR("Couldn't alloc log bio");
>  				goto error;
> 

commit 7efb367320f56fc4d549875b6f3a6940018ef2e5
Author: Mikulas Patocka <mpatocka@redhat.com>
Date:   Tue Aug 30 16:20:55 2016 -0400

    dm log writes: fix bug with too large bios
    
    bio_alloc() can allocate a bio with at most BIO_MAX_PAGES (256) vector
    entries.  However, the incoming bio may have more vector entries if it
    was allocated by other means.  For example, bcache submits bios with
    more than BIO_MAX_PAGES entries.  This results in bio_alloc() failure.
    
    To avoid the failure, change the code so that it allocates bio with at
    most BIO_MAX_PAGES entries.  If the incoming bio has more entries,
    bio_add_page() will fail and a new bio will be allocated - the code that
    handles bio_add_page() failure already exists in the dm-log-writes
    target.
    
    Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
    Reviewed-by: Josef Bacik <jbacik@fb,com>
    Signed-off-by: Mike Snitzer <snitzer@redhat.com>
    Cc: stable@vger.kernel.org # v4.1+

diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index 4cc78ae..ba24f4f 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -260,7 +260,7 @@ static int log_one_block(struct log_writes_c *lc,
 	sector++;
 
 	atomic_inc(&lc->io_blocks);
-	bio = bio_alloc(GFP_KERNEL, block->vec_cnt);
+	bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES));
 	if (!bio) {
 		DMERR("Couldn't alloc log bio");
 		goto error;
@@ -282,7 +282,7 @@ static int log_one_block(struct log_writes_c *lc,
 		if (ret != block->vecs[i].bv_len) {
 			atomic_inc(&lc->io_blocks);
 			submit_bio(WRITE, bio);
-			bio = bio_alloc(GFP_KERNEL, block->vec_cnt - i);
+			bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt - i, BIO_MAX_PAGES));
 			if (!bio) {
 				DMERR("Couldn't alloc log bio");
 				goto error;

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] dm log writes: fix bug with too large bios
  2016-09-22 20:40 ` [PATCH] dm log writes: fix bug with too large bios Mikulas Patocka
@ 2016-10-05 15:38   ` Greg KH
  0 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2016-10-05 15:38 UTC (permalink / raw)
  To: Mikulas Patocka; +Cc: jbacik, snitzer, stable

On Thu, Sep 22, 2016 at 04:40:26PM -0400, Mikulas Patocka wrote:
> Hi
> 
> This is backport of the upstream patch 
> 7efb367320f56fc4d549875b6f3a6940018ef2e5 for the stable kernels.

Thanks, now queued up.

greg k-h

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2016-10-05 15:38 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2016-09-22 13:21 FAILED: patch "[PATCH] dm log writes: fix bug with too large bios" failed to apply to 4.7-stable tree gregkh
2016-09-22 20:40 ` [PATCH] dm log writes: fix bug with too large bios Mikulas Patocka
2016-10-05 15:38   ` Greg KH

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