remarkable-linux/mm
Theodore Ts'o 80a2ea9f85 mm: retry writepages() on ENOMEM when doing an data integrity writeback
Currently, file system's writepages() function must not fail with an
ENOMEM, since if they do, it's possible for buffered data to be lost.
This is because on a data integrity writeback writepages() gets called
but once, and if it returns ENOMEM, if you're lucky the error will get
reflected back to the userspace process calling fsync().  If you
aren't lucky, the user is unmounting the file system, and the dirty
pages will simply be lost.

For this reason, file system code generally will use GFP_NOFS, and in
some cases, will retry the allocation in a loop, on the theory that
"kernel livelocks are temporary; data loss is forever".
Unfortunately, this can indeed cause livelocks, since inside the
writepages() call, the file system is holding various mutexes, and
these mutexes may prevent the OOM killer from killing its targetted
victim if it is also holding on to those mutexes.

A better solution would be to allow writepages() to call the memory
allocator with flags that give greater latitude to the allocator to
fail, and then release its locks and return ENOMEM, and in the case of
background writeback, the writes can be retried at a later time.  In
the case of data-integrity writeback retry after waiting a brief
amount of time.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-04-28 09:51:54 -04:00
..
kasan kasan: report only the first error by default 2017-03-31 17:13:30 -07:00
backing-dev.c bdi: Fix use-after-free in wb_congested_put() 2017-03-08 10:55:17 -07:00
balloon_compaction.c
bootmem.c mm/bootmem.c: cosmetic improvement of code readability 2017-02-22 16:41:29 -08:00
cleancache.c
cma.c mm: cma: print allocation failure reason and bitmap status 2017-02-24 17:46:55 -08:00
cma.h
cma_debug.c mm: cma_alloc: allow to specify GFP mask 2017-02-24 17:46:55 -08:00
compaction.c sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
debug.c mm, debug: print raw struct page data in __dump_page() 2016-12-12 18:55:08 -08:00
debug_page_ref.c
dmapool.c lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
early_ioremap.c
fadvise.c mm: fadvise: avoid expensive remote LRU cache draining after FADV_DONTNEED 2016-12-20 09:48:46 -08:00
failslab.c
filemap.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
frame_vector.c
frontswap.c
gup.c mm, gup: fix typo in gup_p4d_range() 2017-03-13 08:58:09 -07:00
highmem.c
huge_memory.c mm, thp: fix setting of defer+madvise thp defrag mode 2017-04-08 00:47:48 -07:00
hugetlb.c mm/hugetlb.c: don't call region_abort if region_chg fails 2017-03-31 17:13:30 -07:00
hugetlb_cgroup.c
hwpoison-inject.c
init-mm.c
internal.h mm: move pcp and lru-pcp draining into single wq 2017-04-08 00:47:49 -07:00
interval_tree.c
Kconfig mm: THP page cache support for ppc64 2016-12-12 18:55:08 -08:00
Kconfig.debug mm: add arch-independent testcases for RODATA 2017-02-27 18:43:48 -08:00
khugepaged.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/coredump.h> 2017-03-02 08:42:28 +01:00
kmemcheck.c
kmemleak-test.c
kmemleak.c mm: fix section name for .data..ro_after_init 2017-03-31 17:13:30 -07:00
ksm.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/coredump.h> 2017-03-02 08:42:28 +01:00
list_lru.c
maccess.c
madvise.c userfaultfd: non-cooperative: userfaultfd_remove revalidate vma in MADV_DONTNEED 2017-03-09 17:01:10 -08:00
Makefile mm: add arch-independent testcases for RODATA 2017-02-27 18:43:48 -08:00
memblock.c mm/memblock.c: fix memblock_next_valid_pfn() 2017-03-09 17:01:10 -08:00
memcontrol.c mm: do not call mem_cgroup_free() from within mem_cgroup_alloc() 2017-03-09 17:01:10 -08:00
memory-failure.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h> 2017-03-02 08:42:35 +01:00
memory.c mm: introduce __p4d_alloc() 2017-03-09 11:48:48 -08:00
memory_hotplug.c mm: add private lock to serialize memory hotplug operations 2017-03-16 16:56:18 -07:00
mempolicy.c mm/mempolicy.c: fix error handling in set_mempolicy and mbind. 2017-04-08 10:57:55 -07:00
mempool.c
memtest.c
migrate.c mm: migrate: fix remove_migration_pte() for ksm pages 2017-03-31 17:13:30 -07:00
mincore.c mm: remove shmem_mapping() shmem_zero_setup() duplicates 2017-02-24 17:46:56 -08:00
mlock.c Merge branch 'prep-for-5level' 2017-03-10 08:59:07 -08:00
mm_init.c
mmap.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-02 15:20:00 -08:00
mmu_context.c sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
mmu_notifier.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h> 2017-03-02 08:42:28 +01:00
mmzone.c mm/mmzone.c: swap likely to unlikely as code logic is different for next_zones_zonelist() 2017-02-22 16:41:29 -08:00
mprotect.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
mremap.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
msync.c
nobootmem.c
nommu.c Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
oom_kill.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h> 2017-03-02 08:42:35 +01:00
page-writeback.c mm: retry writepages() on ENOMEM when doing an data integrity writeback 2017-04-28 09:51:54 -04:00
page_alloc.c mm: move pcp and lru-pcp draining into single wq 2017-04-08 00:47:49 -07:00
page_counter.c
page_ext.c
page_idle.c mm: fix handling PTE-mapped THPs in page_idle_clear_pte_refs() 2017-02-24 17:46:55 -08:00
page_io.c
page_isolation.c mm, page_alloc: avoid page_to_pfn() when merging buddies 2017-02-22 16:41:27 -08:00
page_owner.c
page_poison.c
page_vma_mapped.c mm: fix page_vma_mapped_walk() for ksm pages 2017-04-08 00:47:48 -07:00
pagewalk.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
percpu-km.c
percpu-vm.c percpu: remove unused chunk_alloc parameter from pcpu_get_pages() 2017-03-06 15:56:55 -05:00
percpu.c percpu: acquire pcpu_lock when updating pcpu_nr_empty_pop_pages 2017-03-06 15:55:39 -05:00
pgtable-generic.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
process_vm_access.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h> 2017-03-02 08:42:28 +01:00
quicklist.c
readahead.c mm: don't cap request size based on read-ahead setting 2016-12-12 18:55:08 -08:00
rmap.c mm: rmap: fix huge file mmap accounting in the memcg stats 2017-03-31 17:13:30 -07:00
rodata_test.c mm: add arch-independent testcases for RODATA 2017-02-27 18:43:48 -08:00
shmem.c Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-03 11:38:56 -08:00
slab.c sched/headers: Prepare to move kstack_end() from <linux/sched.h> to <linux/sched/task_stack.h> 2017-03-02 08:42:39 +01:00
slab.h slab: remove synchronous synchronize_sched() from memcg cache deactivation path 2017-02-22 16:41:27 -08:00
slab_common.c kasan: drain quarantine of memcg slab objects 2017-02-24 17:46:56 -08:00
slob.c slab: introduce __kmemcg_cache_deactivate() 2017-02-22 16:41:27 -08:00
slub.c slub: make sysfs directories for memcg sub-caches optional 2017-02-22 16:41:27 -08:00
sparse-vmemmap.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
sparse.c mm/memory_hotplug: set magic number to page->freelist instead of page->lru.next 2017-02-22 16:41:29 -08:00
swap.c mm: move pcp and lru-pcp draining into single wq 2017-04-08 00:47:49 -07:00
swap_cgroup.c mm, swap_cgroup: reschedule when neeed in swap_cgroup_swapoff() 2017-04-08 00:47:49 -07:00
swap_slots.c mm, swap: Remove WARN_ON_ONCE() in free_swap_slot() 2017-03-21 14:13:19 -07:00
swap_state.c mm/swap: skip readahead only when swap slot cache is enabled 2017-02-22 16:41:30 -08:00
swapfile.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
truncate.c fs: add i_blocksize() 2017-02-27 18:43:46 -08:00
usercopy.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h> 2017-03-02 08:42:35 +01:00
userfaultfd.c mm: convert generic code to 5-level paging 2017-03-09 11:48:47 -08:00
util.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
vmacache.c sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
vmalloc.c mm: don't warn when vmalloc() fails due to a fatal signal 2017-03-16 16:56:18 -07:00
vmpressure.c mm: vmpressure: fix sending wrong events on underflow 2017-02-24 17:46:56 -08:00
vmscan.c sched/headers: Prepare to move the memalloc_noio_*() APIs to <linux/sched/mm.h> 2017-03-02 08:42:33 +01:00
vmstat.c mm: move pcp and lru-pcp draining into single wq 2017-04-08 00:47:49 -07:00
workingset.c mm: workingset: fix premature shadow node shrinking with cgroups 2017-03-31 17:13:30 -07:00
z3fold.c z3fold: fix spinlock unlocking in page reclaim 2017-03-16 16:56:18 -07:00
zbud.c
zpool.c
zsmalloc.c sched/headers: Prepare to remove the <linux/magic.h> include from <linux/sched/task_stack.h> 2017-03-02 08:42:40 +01:00
zswap.c zswap: don't param_set_charp while holding spinlock 2017-02-27 18:43:45 -08:00