The patch titled
Subject: mm: add follow_pte_pmd()
has been removed from the -mm tree. Its filename was
mm-add-follow_pte_pmd.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Subject: mm: add follow_pte_pmd()
Patch series "Write protect DAX PMDs in *sync path".
Currently dax_mapping_entry_mkclean() fails to clean and write protect the
pmd_t of a DAX PMD entry during an *sync operation. This can result in
data loss, as detailed in patch 2.
This series is based on Dan's "libnvdimm-pending" branch, which is the
current home for Jan's "dax: Page invalidation fixes" series. You can
find a working tree here:
https://git.kernel.org/cgit/linux/kernel/git/zwisler/linux.git/log/?h=dax_pmd_clean
This patch (of 2):
Similar to follow_pte(), follow_pte_pmd() allows either a PTE leaf or a
huge page PMD leaf to be found and returned.
Link: http://lkml.kernel.org/r/1482272586-21177-2-git-send-email-ross.zwisler@xxxxxxxxxxxxxxx
Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Suggested-by: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 2 ++
mm/memory.c | 37 ++++++++++++++++++++++++++++++-------
2 files changed, 32 insertions(+), 7 deletions(-)
diff -puN include/linux/mm.h~mm-add-follow_pte_pmd include/linux/mm.h
--- a/include/linux/mm.h~mm-add-follow_pte_pmd
+++ a/include/linux/mm.h
@@ -1212,6 +1212,8 @@ void unmap_mapping_range(struct address_
loff_t const holebegin, loff_t const holelen, int even_cows);
int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp,
spinlock_t **ptlp);
+int follow_pte_pmd(struct mm_struct *mm, unsigned long address,
+ pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp);
int follow_pfn(struct vm_area_struct *vma, unsigned long address,
unsigned long *pfn);
int follow_phys(struct vm_area_struct *vma, unsigned long address,
diff -puN mm/memory.c~mm-add-follow_pte_pmd mm/memory.c
--- a/mm/memory.c~mm-add-follow_pte_pmd
+++ a/mm/memory.c
@@ -3772,8 +3772,8 @@ int __pmd_alloc(struct mm_struct *mm, pu
}
#endif /* __PAGETABLE_PMD_FOLDED */
-static int __follow_pte(struct mm_struct *mm, unsigned long address,
- pte_t **ptepp, spinlock_t **ptlp)
+static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address,
+ pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)
{
pgd_t *pgd;
pud_t *pud;
@@ -3790,11 +3790,20 @@ static int __follow_pte(struct mm_struct
pmd = pmd_offset(pud, address);
VM_BUG_ON(pmd_trans_huge(*pmd));
- if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
- goto out;
- /* We cannot handle huge page PFN maps. Luckily they don't exist. */
- if (pmd_huge(*pmd))
+ if (pmd_huge(*pmd)) {
+ if (!pmdpp)
+ goto out;
+
+ *ptlp = pmd_lock(mm, pmd);
+ if (pmd_huge(*pmd)) {
+ *pmdpp = pmd;
+ return 0;
+ }
+ spin_unlock(*ptlp);
+ }
+
+ if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
goto out;
ptep = pte_offset_map_lock(mm, pmd, address, ptlp);
@@ -3817,9 +3826,23 @@ int follow_pte(struct mm_struct *mm, uns
/* (void) is needed to make gcc happy */
(void) __cond_lock(*ptlp,
- !(res = __follow_pte(mm, address, ptepp, ptlp)));
+ !(res = __follow_pte_pmd(mm, address, ptepp, NULL,
+ ptlp)));
+ return res;
+}
+
+int follow_pte_pmd(struct mm_struct *mm, unsigned long address,
+ pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)
+{
+ int res;
+
+ /* (void) is needed to make gcc happy */
+ (void) __cond_lock(*ptlp,
+ !(res = __follow_pte_pmd(mm, address, ptepp, pmdpp,
+ ptlp)));
return res;
}
+EXPORT_SYMBOL(follow_pte_pmd);
/**
* follow_pfn - look up PFN at a user virtual address
_
Patches currently in -mm which might be from ross.zwisler@xxxxxxxxxxxxxxx are
dax-fix-build-warnings-with-fs_dax-and-fs_iomap.patch
tracing-add-__print_flags_u64.patch
dax-add-tracepoint-infrastructure-pmd-tracing.patch
dax-update-maintainers-entries-for-fs-dax.patch
dax-add-tracepoints-to-dax_pmd_load_hole.patch
dax-add-tracepoints-to-dax_pmd_insert_mapping.patch
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