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| author | Toshi Kani <toshi.kani@hpe.com> | 2016-01-16 01:56:05 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-16 02:56:32 +0100 |
| commit | 59bf4fb9d386601cbaa70a9b00159abb846dedaa (patch) | |
| tree | 0735bb6400f6ed0a3c3be69e1e10018a17fe6a63 /arch/um/include/asm/pgtable-3level.h | |
| parent | mm, dax: fix livelock, allow dax pmd mappings to become writeable (diff) | |
| download | linux-59bf4fb9d386601cbaa70a9b00159abb846dedaa.tar.xz linux-59bf4fb9d386601cbaa70a9b00159abb846dedaa.zip | |
dax: Split pmd map when fallback on COW
An infinite loop of PMD faults was observed when attempted to mlock() a
private read-only PMD mmap'd range of a DAX file.
__dax_pmd_fault() simply returns with VM_FAULT_FALLBACK when falling
back to PTE on COW. However, __handle_mm_fault() returns without
falling back to handle_pte_fault() because a PMD map is present in this
case.
Change __dax_pmd_fault() to split the PMD map, if present, before
returning with VM_FAULT_FALLBACK.
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/um/include/asm/pgtable-3level.h')
0 files changed, 0 insertions, 0 deletions