Messages in this thread |  | | Subject | Re: [PATCH 19/22] mm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot} | From | Ralph Campbell <> | Date | Wed, 3 Jul 2019 10:32:39 -0700 |
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On 6/30/19 11:20 PM, Christoph Hellwig wrote: > We should not have two different error codes for the same condition. In > addition this really complicates the code due to the special handling of > EAGAIN that drops the mmap_sem due to the FAULT_FLAG_ALLOW_RETRY logic > in the core vm. > > Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Probably should update the "Return:" comment above hmm_range_snapshot() too.
> --- > mm/hmm.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/mm/hmm.c b/mm/hmm.c > index c85ed7d4e2ce..d125df698e2b 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -974,7 +974,7 @@ long hmm_range_snapshot(struct hmm_range *range) > do { > /* If range is no longer valid force retry. */ > if (!range->valid) > - return -EAGAIN; > + return -EBUSY; > > vma = find_vma(hmm->mm, start); > if (vma == NULL || (vma->vm_flags & device_vma)) > @@ -1069,10 +1069,8 @@ long hmm_range_fault(struct hmm_range *range, bool block) > > do { > /* If range is no longer valid force retry. */ > - if (!range->valid) { > - up_read(&hmm->mm->mmap_sem); > - return -EAGAIN; > - } > + if (!range->valid) > + return -EBUSY; > > vma = find_vma(hmm->mm, start); > if (vma == NULL || (vma->vm_flags & device_vma)) >
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