If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
However, the bailout for mount is no longer proceeding.
For this reason, using WARN_ON rather than BUG() could prevent this situation.
---
fs/xfs/xfs_mount.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 322da69..10fe000 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -213,8 +213,7 @@ xfs_initialize_perag(
goto out_hash_destroy;
spin_lock(&mp->m_perag_lock);
- if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
- BUG();
+ if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){
spin_unlock(&mp->m_perag_lock);
radix_tree_preload_end();
error = -EEXIST;
--
2.6.2
On Wed, Aug 28, 2019 at 03:47:49PM +0900, Austin Kim wrote:
> If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
> However, the bailout for mount is no longer proceeding.
>
> For this reason, using WARN_ON rather than BUG() could prevent this situation.
> ---
> fs/xfs/xfs_mount.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 322da69..10fe000 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -213,8 +213,7 @@ xfs_initialize_perag(
> goto out_hash_destroy;
>
> spin_lock(&mp->m_perag_lock);
> - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
> - BUG();
> + if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){
Need a space before the brace.
Will fix on import,
Reviewed-by: Darrick J. Wong <[email protected]>
--D
> spin_unlock(&mp->m_perag_lock);
> radix_tree_preload_end();
> error = -EEXIST;
> --
> 2.6.2
>
Dear Mr. Darrick J. Wong
Thanks for reviewing patch. BTW, I have a question for you.
Do I have to update the patch again with 'a space before the brace'?
Or could I just wait for the patch to be imported?
It would be thankful if you give me a feedback.
BR,
Guillermo Austin Kim
2019년 8월 29일 (목) 오전 12:14, Darrick J. Wong <[email protected]>님이 작성:
>
> On Wed, Aug 28, 2019 at 03:47:49PM +0900, Austin Kim wrote:
> > If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
> > However, the bailout for mount is no longer proceeding.
> >
> > For this reason, using WARN_ON rather than BUG() could prevent this situation.
> > ---
> > fs/xfs/xfs_mount.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> > index 322da69..10fe000 100644
> > --- a/fs/xfs/xfs_mount.c
> > +++ b/fs/xfs/xfs_mount.c
> > @@ -213,8 +213,7 @@ xfs_initialize_perag(
> > goto out_hash_destroy;
> >
> > spin_lock(&mp->m_perag_lock);
> > - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
> > - BUG();
> > + if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){
>
> Need a space before the brace.
>
> Will fix on import,
> Reviewed-by: Darrick J. Wong <[email protected]>
>
> --D
>
> > spin_unlock(&mp->m_perag_lock);
> > radix_tree_preload_end();
> > error = -EEXIST;
> > --
> > 2.6.2
> >
On Thu, Aug 29, 2019 at 06:30:43AM +0900, Austin Kim wrote:
> Dear Mr. Darrick J. Wong
>
> Thanks for reviewing patch. BTW, I have a question for you.
>
> Do I have to update the patch again with 'a space before the brace'?
> Or could I just wait for the patch to be imported?
>
> It would be thankful if you give me a feedback.
I made the correction when I imported your patch into my testing tree,
so you don't need to resubmit the patch just to fix that one thing.
However, if you decide to send a new revision *for some other reason*,
then please make the correction in your own tree before resubmitting.
--D
> BR,
> Guillermo Austin Kim
>
> 2019년 8월 29일 (목) 오전 12:14, Darrick J. Wong <[email protected]>님이 작성:
> >
> > On Wed, Aug 28, 2019 at 03:47:49PM +0900, Austin Kim wrote:
> > > If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
> > > However, the bailout for mount is no longer proceeding.
> > >
> > > For this reason, using WARN_ON rather than BUG() could prevent this situation.
> > > ---
> > > fs/xfs/xfs_mount.c | 3 +--
> > > 1 file changed, 1 insertion(+), 2 deletions(-)
> > >
> > > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> > > index 322da69..10fe000 100644
> > > --- a/fs/xfs/xfs_mount.c
> > > +++ b/fs/xfs/xfs_mount.c
> > > @@ -213,8 +213,7 @@ xfs_initialize_perag(
> > > goto out_hash_destroy;
> > >
> > > spin_lock(&mp->m_perag_lock);
> > > - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
> > > - BUG();
> > > + if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){
> >
> > Need a space before the brace.
> >
> > Will fix on import,
> > Reviewed-by: Darrick J. Wong <[email protected]>
> >
> > --D
> >
> > > spin_unlock(&mp->m_perag_lock);
> > > radix_tree_preload_end();
> > > error = -EEXIST;
> > > --
> > > 2.6.2
> > >
On Wed, Aug 28, 2019 at 03:47:49PM +0900, Austin Kim wrote:
> If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
> However, the bailout for mount is no longer proceeding.
>
> For this reason, using WARN_ON rather than BUG() could prevent this situation.
> ---
> fs/xfs/xfs_mount.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 322da69..10fe000 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -213,8 +213,7 @@ xfs_initialize_perag(
> goto out_hash_destroy;
>
> spin_lock(&mp->m_perag_lock);
> - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
> - BUG();
> + if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){
Please make this a WARN_ON_ONCE so that we don't see a flodding of
messages in case of this error.
2019년 8월 29일 (목) 오후 4:56, Christoph Hellwig <[email protected]>님이 작성:
>
> On Wed, Aug 28, 2019 at 03:47:49PM +0900, Austin Kim wrote:
> > If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
> > However, the bailout for mount is no longer proceeding.
> >
> > For this reason, using WARN_ON rather than BUG() could prevent this situation.
> > ---
> > fs/xfs/xfs_mount.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> > index 322da69..10fe000 100644
> > --- a/fs/xfs/xfs_mount.c
> > +++ b/fs/xfs/xfs_mount.c
> > @@ -213,8 +213,7 @@ xfs_initialize_perag(
> > goto out_hash_destroy;
> >
> > spin_lock(&mp->m_perag_lock);
> > - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
> > - BUG();
> > + if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){
>
> Please make this a WARN_ON_ONCE so that we don't see a flodding of
> messages in case of this error.
>
Hello, Mr. Christoph
Thanks for good feedback.
If the kernel log is flooded with error message, as you pointed out,
it may cause other side-effect.(e.g: system non-responsive or lockup)
To. Mr. Darrick J. Wong
If you or other kernel developers do not disagree with the
idea(WARN_ON_ONCE instead of WARN_ON),
do I have to resend the patch with new revision?
The title, the commit message and patch might be changed as followings;
======
xfs: Use WARN_ON_ONCE rather than BUG() for bailout mount-operation
If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
However, the bailout for mount is no longer proceeding.
For this reason, using WARN_ON_ONCE rather than BUG() could prevent
this situation.
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 322da69..d831c13 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -213,8 +213,7 @@ xfs_initialize_perag(
goto out_hash_destroy;
spin_lock(&mp->m_perag_lock);
- if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
- BUG();
+ if (WARN_ON_ONCE(radix_tree_insert(&mp->m_perag_tree,
index, pag))) {
spin_unlock(&mp->m_perag_lock);
radix_tree_preload_end();
error = -EEXIST;
======
BR,
Guillermo Austin Kim
On Thu, Aug 29, 2019 at 12:56:55AM -0700, Christoph Hellwig wrote:
> On Wed, Aug 28, 2019 at 03:47:49PM +0900, Austin Kim wrote:
> > If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
> > However, the bailout for mount is no longer proceeding.
> >
> > For this reason, using WARN_ON rather than BUG() could prevent this situation.
> > ---
> > fs/xfs/xfs_mount.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> > index 322da69..10fe000 100644
> > --- a/fs/xfs/xfs_mount.c
> > +++ b/fs/xfs/xfs_mount.c
> > @@ -213,8 +213,7 @@ xfs_initialize_perag(
> > goto out_hash_destroy;
> >
> > spin_lock(&mp->m_perag_lock);
> > - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
> > - BUG();
> > + if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){
>
> Please make this a WARN_ON_ONCE so that we don't see a flodding of
> messages in case of this error.
How would it flood? If the radix tree insertion fails we dump all the
pag structures and fail log recovery / mount / growfs. I suppose if
one were out of memory and hammering the system hard with repeated mount
calls...
--D
On Thu, Aug 29, 2019 at 09:59:17PM +0900, Austin Kim wrote:
> 2019년 8월 29일 (목) 오후 4:56, Christoph Hellwig <[email protected]>님이 작성:
> >
> > On Wed, Aug 28, 2019 at 03:47:49PM +0900, Austin Kim wrote:
> > > If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
> > > However, the bailout for mount is no longer proceeding.
> > >
> > > For this reason, using WARN_ON rather than BUG() could prevent this situation.
> > > ---
> > > fs/xfs/xfs_mount.c | 3 +--
> > > 1 file changed, 1 insertion(+), 2 deletions(-)
> > >
> > > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> > > index 322da69..10fe000 100644
> > > --- a/fs/xfs/xfs_mount.c
> > > +++ b/fs/xfs/xfs_mount.c
> > > @@ -213,8 +213,7 @@ xfs_initialize_perag(
> > > goto out_hash_destroy;
> > >
> > > spin_lock(&mp->m_perag_lock);
> > > - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
> > > - BUG();
> > > + if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){
> >
> > Please make this a WARN_ON_ONCE so that we don't see a flodding of
> > messages in case of this error.
> >
> Hello, Mr. Christoph
> Thanks for good feedback.
> If the kernel log is flooded with error message, as you pointed out,
> it may cause other side-effect.(e.g: system non-responsive or lockup)
>
> To. Mr. Darrick J. Wong
> If you or other kernel developers do not disagree with the
> idea(WARN_ON_ONCE instead of WARN_ON),
> do I have to resend the patch with new revision?
Yes, and please add your Signed-off-by in the new revision.
--D
> The title, the commit message and patch might be changed as followings;
> ======
> xfs: Use WARN_ON_ONCE rather than BUG() for bailout mount-operation
>
> If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed.
> However, the bailout for mount is no longer proceeding.
>
> For this reason, using WARN_ON_ONCE rather than BUG() could prevent
> this situation.
>
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 322da69..d831c13 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -213,8 +213,7 @@ xfs_initialize_perag(
> goto out_hash_destroy;
>
> spin_lock(&mp->m_perag_lock);
> - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
> - BUG();
> + if (WARN_ON_ONCE(radix_tree_insert(&mp->m_perag_tree,
> index, pag))) {
> spin_unlock(&mp->m_perag_lock);
> radix_tree_preload_end();
> error = -EEXIST;
> ======
>
> BR,
> Guillermo Austin Kim