Messages in this thread Patch in this message | | | From | Austin Kim <> | Date | Thu, 29 Aug 2019 21:59:17 +0900 | Subject | Re: [PATCH] xfs: Use WARN_ON rather than BUG() for bailout mount-operation |
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2019년 8월 29일 (목) 오후 4:56, Christoph Hellwig <hch@infradead.org>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
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