linux/mm
Wu Fengguang 6746aff74d HWPOISON: shmem: call set_page_dirty() with locked page
The dirtying of page and set_page_dirty() can be moved into the page lock.

- In shmem_write_end(), the page was dirtied while the page lock was held,
  but it's being marked dirty just after dropping the page lock.
- In shmem_symlink(), both dirtying and marking can be moved into page lock.

It's valuable for the hwpoison code to know whether one bad page can be dropped
without losing data. It mainly judges by testing the PG_dirty bit after taking
the page lock. So it becomes important that the dirtying of page and the
marking of dirtiness are both done inside the page lock. Which is a common
practice, but sadly not a rule.

The noticeable exceptions are
- mapped pages
- pages with buffer_heads
The above pages could go dirty at any time. Fortunately the hwpoison will
unmap the page and release the buffer_heads beforehand anyway.

Many other types of pages (eg. metadata pages) can also be dirtied at will by
their owners, the hwpoison code cannot do meaningful things to them anyway.
Only the dirtiness of pagecache pages owned by regular files are interested.

v2: AK: Add comment about set_page_dirty rules (suggested by Peter Zijlstra)

Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:14 +02:00
..
allocpercpu.c percpu: use dynamic percpu allocator as the default percpu allocator 2009-06-24 15:13:35 +09:00
backing-dev.c writeback: check for registered bdi in flusher add and inode dirty 2009-09-11 09:20:26 +02:00
bootmem.c kmemleak: Do not report alloc_bootmem blocks as leaks 2009-08-27 14:29:17 +01:00
bounce.c block: remove some includings of blktrace_api.h 2009-06-16 11:19:36 +02:00
debug-pagealloc.c generic debug pagealloc 2009-04-01 08:59:13 -07:00
dmapool.c dmapools: protect page_list walk in show_pools() 2009-06-30 18:56:00 -07:00
fadvise.c readahead: move max_sane_readahead() calls into force_page_cache_readahead() 2009-06-16 19:47:28 -07:00
failslab.c kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c 2009-04-03 12:23:01 +02:00
filemap_xip.c mm: do_xip_mapping_read: fix length calculation 2009-04-02 19:04:49 -07:00
filemap.c vfs: Remove generic_osync_inode() and sync_page_range{_nolock}() 2009-09-14 17:08:17 +02:00
fremap.c Do not account for the address space used by hugetlbfs using VM_ACCOUNT 2009-02-10 10:48:42 -08:00
highmem.c block: remove some includings of blktrace_api.h 2009-06-16 11:19:36 +02:00
hugetlb.c hugetlbfs: export vma_kernel_pagsize to modules 2009-09-10 08:33:01 +03:00
init-mm.c mm: consolidate init_mm definition 2009-06-16 19:47:28 -07:00
internal.h vmscan: do not unconditionally treat zones that fail zone_reclaim() as full 2009-06-16 19:47:45 -07:00
Kconfig Merge branch 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-15 09:19:38 -07:00
Kconfig.debug kmemcheck: enable in the x86 Kconfig 2009-06-15 15:49:15 +02:00
kmemcheck.c kmemcheck: add hooks for the page allocator 2009-06-15 15:48:33 +02:00
kmemleak-test.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
kmemleak.c kmemleak: Improve the "Early log buffer exceeded" error message 2009-09-11 10:42:09 +01:00
maccess.c [S390] maccess: add weak attribute to probe_kernel_write 2009-06-12 10:27:37 +02:00
madvise.c mm: madvise(): correct return code 2009-06-16 19:47:40 -07:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-09-15 09:39:44 -07:00
memcontrol.c cgroup avoid permanent sleep at rmdir 2009-07-29 19:10:35 -07:00
memory_hotplug.c page-allocator: reset wmark_min and inactive ratio of zone when hotplug happens 2009-06-16 19:47:42 -07:00
memory.c HWPOISON: Add poison check to page fault handling 2009-09-16 11:50:08 +02:00
mempolicy.c mm: make set_mempolicy(MPOL_INTERLEAV) N_HIGH_MEMORY aware 2009-08-07 10:39:55 -07:00
mempool.c mempool.c: clean up type-casting 2009-08-10 08:31:16 -07:00
migrate.c HWPOISON: Use bitmask/action code for try_to_unmap behaviour 2009-09-16 11:50:10 +02:00
mincore.c [CVE-2009-0029] System call wrappers part 14 2009-01-14 14:15:24 +01:00
mlock.c mm: remove CONFIG_UNEVICTABLE_LRU config option 2009-06-16 19:47:42 -07:00
mm_init.c mm: mminit_loglevel cannot be __meminitdata anymore 2008-08-20 15:40:30 -07:00
mmap.c Security/SELinux: seperate lsm specific mmap_min_addr 2009-08-17 15:09:11 +10:00
mmu_notifier.c mmu-notifiers: core 2008-07-28 16:30:21 -07:00
mmzone.c [ARM] Double check memmap is actually valid with a memmap has unexpected holes V2 2009-05-18 11:22:24 +01:00
mprotect.c perf_counter: Add mmap event hooks to mprotect() 2009-06-08 23:10:43 +02:00
mremap.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
msync.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
nommu.c nommu: fix error handling in do_mmap_pgoff() 2009-09-05 11:30:42 -07:00
oom_kill.c mm: revert "oom: move oom_adj value" 2009-08-18 16:31:13 -07:00
page_alloc.c HWPOISON: check and isolate corrupted free pages v2 2009-09-16 11:50:12 +02:00
page_cgroup.c memcg: remove some redundant checks 2009-06-18 13:03:47 -07:00
page_io.c mm: remove file argument from swap_readpage() 2009-06-16 19:47:44 -07:00
page_isolation.c memory hotplug: fix page_zone() calculation in test_pages_isolated() 2008-11-06 15:41:19 -08:00
page-writeback.c HWPOISON: shmem: call set_page_dirty() with locked page 2009-09-16 11:50:14 +02:00
pagewalk.c pagemap: pass mm into pagewalkers 2008-06-12 18:05:41 -07:00
percpu.c Merge branch 'for-next' into for-linus 2009-09-15 09:57:19 +09:00
prio_tree.c
quicklist.c percpu: cleanup percpu array definitions 2009-06-24 15:13:45 +09:00
readahead.c readahead: introduce context readahead algorithm 2009-06-16 19:47:30 -07:00
rmap.c HWPOISON: Handle hardware poisoned pages in try_to_unmap 2009-09-16 11:50:11 +02:00
shmem_acl.c shmfs: use 'check_acl' instead of 'permission' 2009-09-08 11:08:46 -07:00
shmem.c HWPOISON: shmem: call set_page_dirty() with locked page 2009-09-16 11:50:14 +02:00
slab.c SLAB: Fix lockdep annotations 2009-06-29 09:57:10 +03:00
slob.c slab: remove duplicate kmem_cache_init_late() declarations 2009-08-06 11:36:25 +03:00
slub.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-09-15 09:39:44 -07:00
sparse-vmemmap.c vmemmap: warn about page_structs with remote distance 2008-11-06 15:41:19 -08:00
sparse.c mm: mminit_validate_memmodel_limits(): remove redundant test 2009-04-01 08:59:11 -07:00
swap_state.c writeback: add name to backing_dev_info 2009-09-11 09:20:26 +02:00
swap.c mm: fix Committed_AS underflow on large NR_CPUS environment 2009-05-02 15:36:10 -07:00
swapfile.c HWPOISON: Add support for poison swap entries v2 2009-09-16 11:50:05 +02:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c HWPOISON: Define a new error_remove_page address space op for async truncation 2009-09-16 11:50:13 +02:00
util.c Merge branches 'slab/documentation', 'slab/fixes', 'slob/cleanups' and 'slub/fixes' into for-linus 2009-06-17 08:30:15 +03:00
vmalloc.c vmalloc: implement pcpu_get_vm_areas() 2009-08-14 15:00:52 +09:00
vmscan.c HWPOISON: Use bitmask/action code for try_to_unmap behaviour 2009-09-16 11:50:10 +02:00
vmstat.c vmscan: count the number of times zone_reclaim() scans and fails 2009-06-16 19:47:46 -07:00