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* [PATCH] btrfs: handle failure of add_pending_csums
@ 2017-12-05 11:51 Nikolay Borisov
  2018-01-05 16:44 ` David Sterba
  0 siblings, 1 reply; 4+ messages in thread
From: Nikolay Borisov @ 2017-12-05 11:51 UTC (permalink / raw)
  To: linux-btrfs; +Cc: Nikolay Borisov

add_pending_csums was added as part of the new data=ordered implementation in
e6dcd2dc9c48 ("Btrfs: New data=ordered implementation"). Even back then it
called the btrfs_csum_file_blocks which can fail but it never bothered handling
the failure. In ENOMEM situation this could lead to the filesystem failing to
write the checksums for a particular extent and not detect this. On read this
could lead to the filesystem erroring out due to crc mismatch. Fix it by
propagating failure from add_pending_csums and handling them

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/inode.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e87ec11c0986..432bffdbb02f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2039,11 +2039,14 @@ static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
 			     struct inode *inode, struct list_head *list)
 {
 	struct btrfs_ordered_sum *sum;
+	int ret;
 
 	list_for_each_entry(sum, list, list) {
 		trans->adding_csums = true;
-		btrfs_csum_file_blocks(trans,
+		ret = btrfs_csum_file_blocks(trans,
 		       BTRFS_I(inode)->root->fs_info->csum_root, sum);
+		if (ret)
+			return ret;
 		trans->adding_csums = false;
 	}
 	return 0;
@@ -3051,7 +3054,11 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 		goto out;
 	}
 
-	add_pending_csums(trans, inode, &ordered_extent->list);
+	ret = add_pending_csums(trans, inode, &ordered_extent->list);
+	if (ret) {
+		btrfs_abort_transaction(trans, ret);
+		goto out;
+	}
 
 	btrfs_ordered_update_i_size(inode, 0, ordered_extent);
 	ret = btrfs_update_inode_fallback(trans, root, inode);
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] btrfs: handle failure of add_pending_csums
  2017-12-05 11:51 [PATCH] btrfs: handle failure of add_pending_csums Nikolay Borisov
@ 2018-01-05 16:44 ` David Sterba
  2018-01-08  8:59   ` [PATCH v2] " Nikolay Borisov
  0 siblings, 1 reply; 4+ messages in thread
From: David Sterba @ 2018-01-05 16:44 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs

On Tue, Dec 05, 2017 at 01:51:43PM +0200, Nikolay Borisov wrote:
> add_pending_csums was added as part of the new data=ordered implementation in
> e6dcd2dc9c48 ("Btrfs: New data=ordered implementation"). Even back then it
> called the btrfs_csum_file_blocks which can fail but it never bothered handling
> the failure. In ENOMEM situation this could lead to the filesystem failing to
> write the checksums for a particular extent and not detect this. On read this
> could lead to the filesystem erroring out due to crc mismatch. Fix it by
> propagating failure from add_pending_csums and handling them
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  fs/btrfs/inode.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index e87ec11c0986..432bffdbb02f 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -2039,11 +2039,14 @@ static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
>  			     struct inode *inode, struct list_head *list)
>  {
>  	struct btrfs_ordered_sum *sum;
> +	int ret;
>  
>  	list_for_each_entry(sum, list, list) {
>  		trans->adding_csums = true;
> -		btrfs_csum_file_blocks(trans,
> +		ret = btrfs_csum_file_blocks(trans,
>  		       BTRFS_I(inode)->root->fs_info->csum_root, sum);
> +		if (ret)
> +			return ret;

The return should come after the line below, otherwise the transaction
will be left in the "adding csums".

>  		trans->adding_csums = false;

...
>  	}
>  	return 0;
> @@ -3051,7 +3054,11 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
>  		goto out;
>  	}
>  
> -	add_pending_csums(trans, inode, &ordered_extent->list);
> +	ret = add_pending_csums(trans, inode, &ordered_extent->list);
> +	if (ret) {
> +		btrfs_abort_transaction(trans, ret);

Ok, we can't do better here, this is too late and
add_pending_csums -> btrfs_csum_file_blocks modifies too much of the
state to be rolled back safely.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v2] btrfs: handle failure of add_pending_csums
  2018-01-05 16:44 ` David Sterba
@ 2018-01-08  8:59   ` Nikolay Borisov
  2018-01-26 14:28     ` Josef Bacik
  0 siblings, 1 reply; 4+ messages in thread
From: Nikolay Borisov @ 2018-01-08  8:59 UTC (permalink / raw)
  To: dsterba; +Cc: linux-btrfs, Nikolay Borisov

add_pending_csums was added as part of the new data=ordered implementation in
e6dcd2dc9c48 ("Btrfs: New data=ordered implementation"). Even back then it
called the btrfs_csum_file_blocks which can fail but it never bothered handling
the failure. In ENOMEM situation this could lead to the filesystem failing to
write the checksums for a particular extent and not detect this. On read this
could lead to the filesystem erroring out due to crc mismatch. Fix it by
propagating failure from add_pending_csums and handling them

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---

V2: 
 Moves the if/ret part after setting ->adding_csums to false. 

 fs/btrfs/inode.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index eebfe2615428..029399593049 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2039,12 +2039,15 @@ static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
 			     struct inode *inode, struct list_head *list)
 {
 	struct btrfs_ordered_sum *sum;
+	int ret;
 
 	list_for_each_entry(sum, list, list) {
 		trans->adding_csums = true;
-		btrfs_csum_file_blocks(trans,
+		ret = btrfs_csum_file_blocks(trans,
 		       BTRFS_I(inode)->root->fs_info->csum_root, sum);
 		trans->adding_csums = false;
+		if (ret)
+			return ret;
 	}
 	return 0;
 }
@@ -3058,7 +3061,11 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 		goto out;
 	}
 
-	add_pending_csums(trans, inode, &ordered_extent->list);
+	ret = add_pending_csums(trans, inode, &ordered_extent->list);
+	if (ret) {
+		btrfs_abort_transaction(trans, ret);
+		goto out;
+	}
 
 	btrfs_ordered_update_i_size(inode, 0, ordered_extent);
 	ret = btrfs_update_inode_fallback(trans, root, inode);
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] btrfs: handle failure of add_pending_csums
  2018-01-08  8:59   ` [PATCH v2] " Nikolay Borisov
@ 2018-01-26 14:28     ` Josef Bacik
  0 siblings, 0 replies; 4+ messages in thread
From: Josef Bacik @ 2018-01-26 14:28 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: dsterba, linux-btrfs

On Mon, Jan 08, 2018 at 10:59:43AM +0200, Nikolay Borisov wrote:
> add_pending_csums was added as part of the new data=ordered implementation in
> e6dcd2dc9c48 ("Btrfs: New data=ordered implementation"). Even back then it
> called the btrfs_csum_file_blocks which can fail but it never bothered handling
> the failure. In ENOMEM situation this could lead to the filesystem failing to
> write the checksums for a particular extent and not detect this. On read this
> could lead to the filesystem erroring out due to crc mismatch. Fix it by
> propagating failure from add_pending_csums and handling them
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>

Reviewed-by: Josef Bacik <jbacik@fb.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-01-26 14:29 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2017-12-05 11:51 [PATCH] btrfs: handle failure of add_pending_csums Nikolay Borisov
2018-01-05 16:44 ` David Sterba
2018-01-08  8:59   ` [PATCH v2] " Nikolay Borisov
2018-01-26 14:28     ` Josef Bacik

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