* [PATCH] btrfs: fallback to vmalloc in btrfs_compare_tree
@ 2016-03-30 14:05 David Sterba
2016-03-30 17:10 ` Liu Bo
2016-03-30 17:55 ` Jean-Denis Girard
0 siblings, 2 replies; 4+ messages in thread
From: David Sterba @ 2016-03-30 14:05 UTC (permalink / raw)
To: linux-btrfs; +Cc: David Sterba
The allocation of node could fail if the memory is too fragmented for a
given node size, practically observed with 64k.
http://article.gmane.org/gmane.comp.file-systems.btrfs/54689
Reported-by: Jean-Denis Girard <jd.girard@sysnux.pf>
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/ctree.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 77592931ab4f..ec7928a27aaa 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -19,6 +19,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/rbtree.h>
+#include <linux/vmalloc.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
@@ -5361,10 +5362,13 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
goto out;
}
- tmp_buf = kmalloc(left_root->nodesize, GFP_KERNEL);
+ tmp_buf = kmalloc(left_root->nodesize, GFP_KERNEL | __GFP_NOWARN);
if (!tmp_buf) {
- ret = -ENOMEM;
- goto out;
+ tmp_buf = vmalloc(left_root->nodesize);
+ if (!tmp_buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
}
left_path->search_commit_root = 1;
@@ -5565,7 +5569,7 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
out:
btrfs_free_path(left_path);
btrfs_free_path(right_path);
- kfree(tmp_buf);
+ kvfree(tmp_buf);
return ret;
}
--
2.7.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] btrfs: fallback to vmalloc in btrfs_compare_tree
2016-03-30 14:05 [PATCH] btrfs: fallback to vmalloc in btrfs_compare_tree David Sterba
@ 2016-03-30 17:10 ` Liu Bo
2016-03-30 17:50 ` David Sterba
2016-03-30 17:55 ` Jean-Denis Girard
1 sibling, 1 reply; 4+ messages in thread
From: Liu Bo @ 2016-03-30 17:10 UTC (permalink / raw)
To: David Sterba; +Cc: linux-btrfs
On Wed, Mar 30, 2016 at 04:05:43PM +0200, David Sterba wrote:
> The allocation of node could fail if the memory is too fragmented for a
> given node size, practically observed with 64k.
It's not a critical path. Why not use vmalloc directly?
Thanks,
-liubo
>
> http://article.gmane.org/gmane.comp.file-systems.btrfs/54689
>
> Reported-by: Jean-Denis Girard <jd.girard@sysnux.pf>
> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
> fs/btrfs/ctree.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> index 77592931ab4f..ec7928a27aaa 100644
> --- a/fs/btrfs/ctree.c
> +++ b/fs/btrfs/ctree.c
> @@ -19,6 +19,7 @@
> #include <linux/sched.h>
> #include <linux/slab.h>
> #include <linux/rbtree.h>
> +#include <linux/vmalloc.h>
> #include "ctree.h"
> #include "disk-io.h"
> #include "transaction.h"
> @@ -5361,10 +5362,13 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
> goto out;
> }
>
> - tmp_buf = kmalloc(left_root->nodesize, GFP_KERNEL);
> + tmp_buf = kmalloc(left_root->nodesize, GFP_KERNEL | __GFP_NOWARN);
> if (!tmp_buf) {
> - ret = -ENOMEM;
> - goto out;
> + tmp_buf = vmalloc(left_root->nodesize);
> + if (!tmp_buf) {
> + ret = -ENOMEM;
> + goto out;
> + }
> }
>
> left_path->search_commit_root = 1;
> @@ -5565,7 +5569,7 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
> out:
> btrfs_free_path(left_path);
> btrfs_free_path(right_path);
> - kfree(tmp_buf);
> + kvfree(tmp_buf);
> return ret;
> }
>
> --
> 2.7.1
>
> --
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] btrfs: fallback to vmalloc in btrfs_compare_tree
2016-03-30 17:10 ` Liu Bo
@ 2016-03-30 17:50 ` David Sterba
0 siblings, 0 replies; 4+ messages in thread
From: David Sterba @ 2016-03-30 17:50 UTC (permalink / raw)
To: Liu Bo; +Cc: linux-btrfs
On Wed, Mar 30, 2016 at 10:10:45AM -0700, Liu Bo wrote:
> On Wed, Mar 30, 2016 at 04:05:43PM +0200, David Sterba wrote:
> > The allocation of node could fail if the memory is too fragmented for a
> > given node size, practically observed with 64k.
>
> It's not a critical path. Why not use vmalloc directly?
We should try to avoid vmalloc if possible.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] btrfs: fallback to vmalloc in btrfs_compare_tree
2016-03-30 14:05 [PATCH] btrfs: fallback to vmalloc in btrfs_compare_tree David Sterba
2016-03-30 17:10 ` Liu Bo
@ 2016-03-30 17:55 ` Jean-Denis Girard
1 sibling, 0 replies; 4+ messages in thread
From: Jean-Denis Girard @ 2016-03-30 17:55 UTC (permalink / raw)
To: David Sterba, linux-btrfs
Hi David,
Le 30/03/2016 04:05, David Sterba a écrit :
> The allocation of node could fail if the memory is too fragmented for a
> given node size, practically observed with 64k.
>
> http://article.gmane.org/gmane.comp.file-systems.btrfs/54689
>
> Reported-by: Jean-Denis Girard <jd.girard@sysnux.pf>
> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
> fs/btrfs/ctree.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> index 77592931ab4f..ec7928a27aaa 100644
> --- a/fs/btrfs/ctree.c
> +++ b/fs/btrfs/ctree.c
> @@ -19,6 +19,7 @@
> #include <linux/sched.h>
> #include <linux/slab.h>
> #include <linux/rbtree.h>
> +#include <linux/vmalloc.h>
> #include "ctree.h"
> #include "disk-io.h"
> #include "transaction.h"
> @@ -5361,10 +5362,13 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
> goto out;
> }
>
> - tmp_buf = kmalloc(left_root->nodesize, GFP_KERNEL);
> + tmp_buf = kmalloc(left_root->nodesize, GFP_KERNEL | __GFP_NOWARN);
> if (!tmp_buf) {
> - ret = -ENOMEM;
> - goto out;
> + tmp_buf = vmalloc(left_root->nodesize);
> + if (!tmp_buf) {
> + ret = -ENOMEM;
> + goto out;
> + }
> }
>
> left_path->search_commit_root = 1;
> @@ -5565,7 +5569,7 @@ int btrfs_compare_trees(struct btrfs_root *left_root,
> out:
> btrfs_free_path(left_path);
> btrfs_free_path(right_path);
> - kfree(tmp_buf);
> + kvfree(tmp_buf);
> return ret;
> }
>
>
I adapted / applied the patch for kernel-4.4.6, rebooted and now the
backup completes without error, thanks a lot!
Tested by: Jean-Denis Girard <jd.girard@sysnux.pf>
Thanks,
--
Jean-Denis Girard
SysNux Systèmes Linux en Polynésie française
http://www.sysnux.pf/ Tél: +689 40.50.10.40 / GSM: +689 87.79.75.27
^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-03-30 14:05 [PATCH] btrfs: fallback to vmalloc in btrfs_compare_tree David Sterba
2016-03-30 17:10 ` Liu Bo
2016-03-30 17:50 ` David Sterba
2016-03-30 17:55 ` Jean-Denis Girard
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