Hugh Dickins 9b15b817f3 swap: fix shmem swapping when more than 8 areas ... Minchan Kim reports that when a system has many swap areas, and tmpfs swaps out to the ninth or more, shmem_getpage_gfp()'s attempts to read back the page cannot locate it, and the read fails with -ENOMEM. Whoops. Yes, I blindly followed read_swap_header()'s pte_to_swp_entry( swp_entry_to_pte()) technique for determining maximum usable swap offset, without stopping to realize that that actually depends upon the pte swap encoding shifting swap offset to the higher bits and truncating it there. Whereas our radix_tree swap encoding leaves offset in the lower bits: it's swap "type" (that is, index of swap area) that was truncated. Fix it by reducing the SWP_TYPE_SHIFT() in swapops.h, and removing the broken radix_to_swp_entry(swp_to_radix_entry()) from read_swap_header(). This does not reduce the usable size of a swap area any further, it leaves it as claimed when making the original commit: no change from 3.0 on x86_64, nor on i386 without PAE; but 3.0's 512GB is reduced to 128GB per swapfile on i386 with PAE. It's not a change I would have risked five years ago, but with x86_64 supported for ten years, I believe it's appropriate now. Hmm, and what if some architecture implements its swap pte with offset encoded below type? That would equally break the maximum usable swap offset check. Happily, they all follow the same tradition of encoding offset above type, but I'll prepare a check on that for next. Reported-and-Reviewed-and-Tested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org [3.1, 3.2, 3.3, 3.4] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2012-06-15 21:48:14 -07:00
..
backing-dev.c	backing-dev: fix wakeup timer races with bdi_unregister()	2012-02-01 16:52:49 +08:00
bootmem.c	mm/bootmem.c: cleanup on addition to bootmem data list	2012-05-29 16:22:24 -07:00
bounce.c	mm: remove the second argument of k[un]map_atomic()	2012-03-20 21:48:27 +08:00
cleancache.c	->encode_fh() API change	2012-05-29 23:28:33 -04:00
compaction.c	Revert "mm: compaction: handle incorrect MIGRATE_UNMOVABLE type pageblocks"	2012-06-03 20:05:57 -07:00
debug-pagealloc.c	mm, x86: Remove debug_pagealloc_enabled	2011-12-06 09:24:07 +01:00
dmapool.c	mm: fix implicit stat.h usage in dmapool.c	2011-10-31 09:20:12 -04:00
fadvise.c	fadvise: only initiate writeback for specified range with FADV_DONTNEED	2012-01-10 16:30:43 -08:00
failslab.c	switch debugfs to umode_t	2012-01-03 22:54:56 -05:00
filemap_xip.c	fs: introduce inode operation ->update_time	2012-06-01 12:07:25 -04:00
filemap.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2012-06-01 10:34:35 -07:00
fremap.c	mm: delete various needless include <linux/module.h>	2011-10-31 09:20:11 -04:00
frontswap.c	frontswap: s/put_page/store/g s/get_page/load	2012-05-15 11:34:08 -04:00
highmem.c	Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux	2011-11-06 19:44:47 -08:00
huge_memory.c	mm/memcg: apply add/del_page to lruvec	2012-05-29 16:22:28 -07:00
hugetlb.c	mm: fix vma_resv_map() NULL pointer	2012-05-30 08:48:13 -07:00
hwpoison-inject.c	HWPOISON: Clean up memory_failure() vs. __memory_failure()	2012-01-03 12:06:32 -08:00
init-mm.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
internal.h	Revert "mm: compaction: handle incorrect MIGRATE_UNMOVABLE type pageblocks"	2012-06-03 20:05:57 -07:00
Kconfig	Frontswap provides a "transcendent memory" interface for swap pages.	2012-06-04 12:28:45 -07:00
Kconfig.debug	mm: more intensive memory corruption debugging	2012-01-10 16:30:42 -08:00
kmemcheck.c
kmemleak-test.c	kmemleak: remove memset by using kzalloc	2011-01-27 18:31:51 +00:00
kmemleak.c	kmemleak: Disable early logging when kmemleak is off by default	2012-01-20 16:57:05 +00:00
ksm.c	ksm: cleanup: introduce find_mergeable_vma()	2012-03-21 17:54:59 -07:00
maccess.c	mm: Map most files to use export.h instead of module.h	2011-10-31 09:20:12 -04:00
madvise.c	mm/fs: route MADV_REMOVE to FALLOC_FL_PUNCH_HOLE	2012-05-29 16:22:22 -07:00
Makefile	Frontswap provides a "transcendent memory" interface for swap pages.	2012-06-04 12:28:45 -07:00
memblock.c	memblock: Document memblock_is_region_{memory,reserved}()	2012-06-08 11:59:46 +02:00
memcontrol.c	memcg: decrement static keys at real destroy time	2012-05-29 16:22:28 -07:00
memory_hotplug.c	mm: print physical addresses consistently with other parts of kernel	2012-05-29 16:22:21 -07:00
memory-failure.c	mm/memory_failure: let the compiler add the function name	2012-05-29 16:22:18 -07:00
memory.c	thp, memcg: split hugepage for memcg oom on cow	2012-05-29 16:22:19 -07:00
mempolicy.c	mm: do_migrate_pages(): rename arguments	2012-05-29 16:22:20 -07:00
mempool.c	mempool: fix first round failure behavior	2012-01-10 16:30:45 -08:00
migrate.c	mm: fix warning in __set_page_dirty_nobuffers	2012-06-03 20:05:47 -07:00
mincore.c	mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode	2012-03-21 17:54:54 -07:00
mlock.c	vm: avoid using find_vma_prev() unnecessarily	2012-03-06 18:23:36 -08:00
mm_init.c	mm: Map most files to use export.h instead of module.h	2011-10-31 09:20:12 -04:00
mmap.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2012-06-01 10:34:35 -07:00
mmu_context.c	mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat()	2012-03-21 17:54:59 -07:00
mmu_notifier.c	mm: Map most files to use export.h instead of module.h	2011-10-31 09:20:12 -04:00
mmzone.c	mm: add link from struct lruvec to struct zone	2012-05-29 16:22:26 -07:00
mprotect.c	Merge branch 'akpm' (Andrew's patch-bomb)	2012-03-22 09:04:48 -07:00
mremap.c	move security_mmap_addr() to saner place	2012-06-01 10:37:16 -04:00
msync.c
nobootmem.c	mm: remove sparsemem allocation details from the bootmem allocator	2012-05-29 16:22:22 -07:00
nommu.c	nommu: fix compilation of nommu.c	2012-06-04 17:17:31 -04:00
oom_kill.c	mm, oom: fix badness score underflow	2012-06-08 15:07:35 -07:00
page_alloc.c	Revert "mm: compaction: handle incorrect MIGRATE_UNMOVABLE type pageblocks"	2012-06-03 20:05:57 -07:00
page_cgroup.c	page_cgroup: fix horrid swap accounting regression	2012-03-06 08:18:23 -08:00
page_io.c	frontswap: s/put_page/store/g s/get_page/load	2012-05-15 11:34:08 -04:00
page_isolation.c	mm: page_isolation: MIGRATE_CMA isolation functions added	2012-05-21 15:09:33 +02:00
page-writeback.c	writeback: initialize global_dirty_limit	2012-05-06 13:41:58 +08:00
pagewalk.c	mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode	2012-03-21 17:54:54 -07:00
percpu-km.c
percpu-vm.c	percpu: use bitmap_clear	2012-01-20 09:23:16 -08:00
percpu.c	kmemleak: Fix the kmemleak tracking of the percpu areas with !SMP	2012-05-09 10:13:29 -07:00
pgtable-generic.c	arch/tile: allow building Linux with transparent huge pages enabled	2012-05-25 12:48:21 -04:00
prio_tree.c	sanitize <linux/prefetch.h> usage	2011-05-20 12:50:29 -07:00
process_vm_access.c	aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()	2012-05-31 17:49:32 -07:00
quicklist.c	mm: delete various needless include <linux/module.h>	2011-10-31 09:20:11 -04:00
readahead.c	mm: move readahead syscall to mm/readahead.c	2012-05-29 16:22:23 -07:00
rmap.c	mm: remove swap token code	2012-05-29 16:22:19 -07:00
shmem.c	shmem: replace_page must flush_dcache and others	2012-06-07 14:43:54 -07:00
slab.c	Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux	2012-03-28 15:04:26 -07:00
slob.c	mm: Map most files to use export.h instead of module.h	2011-10-31 09:20:12 -04:00
slub.c	Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux	2012-06-01 16:50:23 -07:00
sparse-vmemmap.c	mm: delete various needless include <linux/module.h>	2011-10-31 09:20:11 -04:00
sparse.c	mm: remove sparsemem allocation details from the bootmem allocator	2012-05-29 16:22:22 -07:00
swap_state.c	mm: fix s390 BUG by __set_page_dirty_no_writeback on swap	2012-04-23 18:19:22 -07:00
swap.c	mm/memcg: apply add/del_page to lruvec	2012-05-29 16:22:28 -07:00
swapfile.c	swap: fix shmem swapping when more than 8 areas	2012-06-15 21:48:14 -07:00
truncate.c	mm/fs: remove truncate_range	2012-05-29 16:22:23 -07:00
util.c	new helper: vm_mmap_pgoff()	2012-06-01 10:37:18 -04:00
vmalloc.c	mm: fix faulty initialization in vmalloc_init()	2012-05-29 16:22:24 -07:00
vmscan.c	mm/memcg: apply add/del_page to lruvec	2012-05-29 16:22:28 -07:00
vmstat.c	mm/vmstat.c: remove debug fs entries on failure of file creation and made extfrag_debug_root dentry local	2012-05-29 16:22:19 -07:00