diff options
| author | Alistair Popple <apopple@nvidia.com> | 2025-02-28 14:31:08 +1100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-03-17 22:06:39 -0700 |
| commit | ec2e0cc67f9c3ed5926da390ad86b25c142a2e4a (patch) | |
| tree | 419c736ced7b8690c76519f5fd44d0cb8ef3e546 /mm/memory.c | |
| parent | 15a64311e0ae069196b7d3b88d0c11e0b2ad733e (diff) | |
mm/memory: add vmf_insert_page_mkwrite()
Currently to map a DAX page the DAX driver calls vmf_insert_pfn. This
creates a special devmap PTE entry for the pfn but does not take a
reference on the underlying struct page for the mapping. This is because
DAX page refcounts are treated specially, as indicated by the presence of
a devmap entry.
To allow DAX page refcounts to be managed the same as normal page
refcounts introduce vmf_insert_page_mkwrite(). This will take a reference
on the underlying page much the same as vmf_insert_page, except it also
permits upgrading an existing mapping to be writable if
requested/possible.
Link: https://lkml.kernel.org/r/4ce3aa984c060f370105e0bfef1035869578be47.1740713401.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Asahi Lina <lina@asahilina.net>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Dan Wiliams <dan.j.williams@intel.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: linmiaohe <linmiaohe@huawei.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index 705c902cf56a..f09b4a1d09a8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2643,6 +2643,26 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma, return VM_FAULT_NOPAGE; } +vm_fault_t vmf_insert_page_mkwrite(struct vm_fault *vmf, struct page *page, + bool write) +{ + pgprot_t pgprot = vmf->vma->vm_page_prot; + unsigned long addr = vmf->address; + int err; + + if (addr < vmf->vma->vm_start || addr >= vmf->vma->vm_end) + return VM_FAULT_SIGBUS; + + err = insert_page(vmf->vma, addr, page, pgprot, write); + if (err == -ENOMEM) + return VM_FAULT_OOM; + if (err < 0 && err != -EBUSY) + return VM_FAULT_SIGBUS; + + return VM_FAULT_NOPAGE; +} +EXPORT_SYMBOL_GPL(vmf_insert_page_mkwrite); + vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr, pfn_t pfn) { |