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io_uring: rsrc: delegate VMA file-backed check to GUP 

Now that the GUP explicitly checks FOLL_LONGTERM pin_user_pages() for
broken file-backed mappings in "mm/gup: disallow FOLL_LONGTERM GUP-nonfast
writing to file-backed mappings", there is no need to explicitly check VMAs
for this condition, so simply remove this logic from io_uring altogether.

Link: https://lkml.kernel.org/r/e4a4efbda9cd12df71e0ed81796dc630231a1ef2.1684350871.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Lorenzo Stoakes 2023-05-17 20:25:42 +01:00 committed by Andrew Morton
parent ca5e863233
commit 34ed8d0dcd
1 changed files with 6 additions and 28 deletions
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34
io_uring/rsrc.c
View File

@ -1030,9 +1030,8 @@ static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages)
{
unsigned long start, end, nr_pages;
struct vm_area_struct **vmas = NULL;
struct page **pages = NULL;
int i, pret, ret = -ENOMEM;
int pret, ret = -ENOMEM;
end = (ubuf + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
start = ubuf >> PAGE_SHIFT;
@ -1042,45 +1041,24 @@ struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages)
if (!pages)
goto done;
vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
GFP_KERNEL);
if (!vmas)
goto done;
ret = 0;
mmap_read_lock(current->mm);
pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
pages, vmas);
if (pret == nr_pages) {
/* don't support file backed memory */
for (i = 0; i < nr_pages; i++) {
struct vm_area_struct *vma = vmas[i];
if (vma_is_shmem(vma))
continue;
if (vma->vm_file &&
!is_file_hugepages(vma->vm_file)) {
ret = -EOPNOTSUPP;
break;
}
}
pages, NULL);
if (pret == nr_pages)
*npages = nr_pages;
} else {
else
ret = pret < 0 ? pret : -EFAULT;
}
mmap_read_unlock(current->mm);
if (ret) {
/*
* if we did partial map, or found file backed vmas,
* release any pages we did get
*/
/* if we did partial map, release any pages we did get */
if (pret > 0)
unpin_user_pages(pages, pret);
goto done;
}
ret = 0;
done:
kvfree(vmas);
if (ret < 0) {
kvfree(pages);
pages = ERR_PTR(ret);