OpenCloudOS-Kernel/mm
John Hubbard c36c04c2e1 Revert "mm/gup: small refactoring: simplify try_grab_page()"
This reverts commit 54d516b1d6

That commit did a refactoring that effectively combined fast and slow
gup paths (again).  And that was again incorrect, for two reasons:

 a) Fast gup and slow gup get reference counts on pages in different
    ways and with different goals: see Linus' writeup in commit
    cd1adf1b63 ("Revert "mm/gup: remove try_get_page(), call
    try_get_compound_head() directly""), and

 b) try_grab_compound_head() also has a specific check for
    "FOLL_LONGTERM && !is_pinned(page)", that assumes that the caller
    can fall back to slow gup. This resulted in new failures, as
    recently report by Will McVicker [1].

But (a) has problems too, even though they may not have been reported
yet.  So just revert this.

Link: https://lore.kernel.org/r/20220131203504.3458775-1-willmcvicker@google.com [1]
Fixes: 54d516b1d6 ("mm/gup: small refactoring: simplify try_grab_page()")
Reported-and-tested-by: Will McVicker <willmcvicker@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Minchan Kim <minchan@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: stable@vger.kernel.org # 5.15
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-03 06:51:42 -08:00
..
damon
kasan
kfence
Kconfig mm: hide the FRONTSWAP Kconfig symbol 2022-01-22 08:33:38 +02:00
Kconfig.debug
Makefile
backing-dev.c
balloon_compaction.c
bootmem_info.c
cma.c
cma.h
cma_debug.c
cma_sysfs.c
compaction.c
debug.c
debug_page_ref.c
debug_vm_pgtable.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c Merge branch 'akpm' (patches from Andrew) 2022-01-22 11:28:23 +02:00
folio-compat.c
frontswap.c frontswap: remove support for multiple ops 2022-01-22 08:33:38 +02:00
gup.c Revert "mm/gup: small refactoring: simplify try_grab_page()" 2022-02-03 06:51:42 -08:00
gup_test.c
gup_test.h
highmem.c
hmm.c
huge_memory.c
hugetlb.c
hugetlb_cgroup.c
hugetlb_vmemmap.c
hugetlb_vmemmap.h
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
io-mapping.c
ioremap.c
khugepaged.c
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c
mapping_dirty_helpers.c
memblock.c
memcontrol.c
memfd.c
memory-failure.c memory-failure: fetch compound_head after pgmap_pfn_valid() 2022-01-30 09:56:58 +02:00
memory.c
memory_hotplug.c
mempolicy.c
mempool.c
memremap.c
memtest.c
migrate.c
mincore.c
mlock.c
mm_init.c
mmap.c
mmap_lock.c
mmu_gather.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nommu.c
oom_kill.c
page-writeback.c
page_alloc.c
page_counter.c
page_ext.c
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c
page_vma_mapped.c
pagewalk.c
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
pgalloc-track.h
pgtable-generic.c
process_vm_access.c
ptdump.c
readahead.c
rmap.c
rodata_test.c
secretmem.c
shmem.c
shuffle.c
shuffle.h
slab.c
slab.h
slab_common.c
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap.c
swap_cgroup.c
swap_slots.c
swap_state.c
swapfile.c mm: mark swap_lock and swap_active_head static 2022-01-22 08:33:38 +02:00
truncate.c
usercopy.c
userfaultfd.c
util.c
vmacache.c
vmalloc.c
vmpressure.c
vmscan.c
vmstat.c
workingset.c
z3fold.c
zbud.c
zpool.c
zsmalloc.c
zswap.c frontswap: remove support for multiple ops 2022-01-22 08:33:38 +02:00