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| author | Christoph Hellwig <hch@lst.de> | 2019-07-24 08:52:52 +0200 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-07-25 16:14:39 -0300 |
| commit | 2bcbeaefde2f0384d6ad351c151b1a9fe7791a0a (patch) | |
| tree | c7de00fb18f33e57803a35263197776a1c209cb6 /mm | |
| parent | 5f9e832c137075045d15cd6899ab0505cfb2ca4b (diff) | |
| download | lwn-2bcbeaefde2f0384d6ad351c151b1a9fe7791a0a.tar.gz lwn-2bcbeaefde2f0384d6ad351c151b1a9fe7791a0a.zip | |
mm/hmm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot}
We should not have two different error codes for the same
condition. EAGAIN must be reserved for the FAULT_FLAG_ALLOW_RETRY retry
case and signals to the caller that the mmap_sem has been unlocked.
Use EBUSY for the !valid case so that callers can get the locking right.
Link: https://lore.kernel.org/r/20190724065258.16603-2-hch@lst.de
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
[jgg: elaborated commit message]
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/hmm.c | 10 |
1 files changed, 4 insertions, 6 deletions
@@ -946,7 +946,7 @@ EXPORT_SYMBOL(hmm_range_unregister); * @range: range * Return: -EINVAL if invalid argument, -ENOMEM out of memory, -EPERM invalid * permission (for instance asking for write and range is read only), - * -EAGAIN if you need to retry, -EFAULT invalid (ie either no valid + * -EBUSY if you need to retry, -EFAULT invalid (ie either no valid * vma or it is illegal to access that range), number of valid pages * in range->pfns[] (from range start address). * @@ -967,7 +967,7 @@ long hmm_range_snapshot(struct hmm_range *range) do { /* If range is no longer valid force retry.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& device_vma)) @@ -1062,10 +1062,8 @@ long hmm_range_fault(struct hmm_range *range, bool block) do { /* If range is no longer valid force retry.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)) |