Tejun Heo b817525a4a writeback: bdi_writeback iteration must not skip dying ones ... bdi_for_each_wb() is used in several places to wake up or issue writeback work items to all wb's (bdi_writeback's) on a given bdi. The iteration is performed by walking bdi->cgwb_tree; however, the tree only indexes wb's which are currently active. For example, when a memcg gets associated with a different blkcg, the old wb is removed from the tree so that the new one can be indexed. The old wb starts dying from then on but will linger till all its inodes are drained. As these dying wb's may still host dirty inodes, writeback operations which affect all wb's must include them. bdi_for_each_wb() skipping dying wb's led to sync(2) missing and failing to sync the inodes belonging to those wb's. This patch adds a RCU protected @bdi->wb_list which lists all wb's beloinging to that bdi. wb's are added on creation and removed on release rather than on the start of destruction. bdi_for_each_wb() usages are replaced with list_for_each[_continue]_rcu() iterations over @bdi->wb_list and bdi_for_each_wb() and its helpers are removed. v2: Updated as per Jan. last_wb ref leak in bdi_split_work_to_wbs() fixed and unnecessary list head severing in cgwb_bdi_destroy() removed. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Artem Bityutskiy <dedekind1@gmail.com> Fixes: ebe41ab0c7 ("writeback: implement bdi_for_each_wb()") Link: http://lkml.kernel.org/g/1443012552.19983.209.camel@gmail.com Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>		2015-10-12 10:31:12 -06:00
..
kasan	kasan: fix last shadow judgement in memory_is_poisoned_16()	2015-09-17 21:16:07 -07:00
backing-dev.c	writeback: bdi_writeback iteration must not skip dying ones	2015-10-12 10:31:12 -06:00
balloon_compaction.c
bootmem.c	bootmem: avoid freeing to bootmem after bootmem is done	2015-09-08 15:35:28 -07:00
cleancache.c	cleancache: remove limit on the number of cleancache enabled filesystems	2015-04-14 16:49:03 -07:00
cma_debug.c	mm/cma_debug: correct size input to bitmap function	2015-07-17 16:39:54 -07:00
cma.c	mm/memblock: add extra "flags" to memblock to allow selection of memory based on attribute	2015-06-24 17:49:44 -07:00
cma.h	mm: cma: mark cma_bitmap_maxno() inline in header	2015-08-14 15:56:32 -07:00
compaction.c	mm/compaction: correct to flush migrated pages if pageblock skip happens	2015-09-08 15:35:28 -07:00
debug-pagealloc.c
debug.c	mm: introduce idle page tracking	2015-09-10 13:29:01 -07:00
dmapool.c	dmapool: fix overflow condition in pool_find_page()	2015-10-01 21:42:35 -04:00
early_ioremap.c	mm/early_ioremap: add explicit #include of asm/early_ioremap.h	2015-09-11 15:21:34 -07:00
fadvise.c	writeback: implement and use inode_congested()	2015-06-02 08:33:35 -06:00
failslab.c
filemap.c	Revert "fs: do not prefault sys_write() user buffer pages"	2015-10-07 08:32:38 +01:00
frame_vector.c	[media] mm: Provide new get_vaddr_frames() helper	2015-08-16 13:02:47 -03:00
frontswap.c	frontswap: allow multiple backends	2015-06-24 17:49:45 -07:00
gup.c	mm: make GUP handle pfn mapping unless FOLL_GET is requested	2015-09-04 16:54:41 -07:00
highmem.c
huge_memory.c	mm: introduce idle page tracking	2015-09-10 13:29:01 -07:00
hugetlb_cgroup.c
hugetlb.c	mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault	2015-10-01 21:42:35 -04:00
hwpoison-inject.c	hwpoison: use page_cgroup_ino for filtering by memcg	2015-09-10 13:29:01 -07:00
init-mm.c
internal.h	mm/compaction: correct to flush migrated pages if pageblock skip happens	2015-09-08 15:35:28 -07:00
interval_tree.c
Kconfig	media updates for v4.3-rc1	2015-09-11 16:42:39 -07:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c	kmemleak: use seq_hex_dump() to dump buffers	2015-09-10 13:29:01 -07:00
ksm.c	mm: remove rest of ACCESS_ONCE() usages	2015-04-15 16:35:18 -07:00
list_lru.c	list_lru: don't call list_lru_from_kmem if the list_head is empty	2015-09-08 15:35:28 -07:00
maccess.c	lib: move strncpy_from_unsafe() into mm/maccess.c	2015-08-31 12:36:10 -07:00
madvise.c	mm: madvise allow remove operation for hugetlbfs	2015-09-08 15:35:28 -07:00
Makefile	media updates for v4.3-rc1	2015-09-11 16:42:39 -07:00
memblock.c	mm/memblock.c: fix comment in __next_mem_range()	2015-09-08 15:35:28 -07:00
memcontrol.c	memcg: remove pcp_counter_lock	2015-10-01 21:42:35 -04:00
memory_hotplug.c	libnvdimm for 4.3:	2015-09-08 14:35:59 -07:00
memory-failure.c	hwpoison: use page_cgroup_ino for filtering by memcg	2015-09-10 13:29:01 -07:00
memory.c	mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd()	2015-09-10 13:29:01 -07:00
mempolicy.c	mm: rename alloc_pages_exact_node() to __alloc_pages_node()	2015-09-08 15:35:28 -07:00
mempool.c	mm/mempool: allow NULL `pool' pointer in mempool_destroy()	2015-09-08 15:35:28 -07:00
memtest.c	memtest: remove unused header files	2015-09-08 15:35:28 -07:00
migrate.c	memcg: fix dirty page migration	2015-10-01 21:42:35 -04:00
mincore.c
mlock.c	userfaultfd: teach vma_merge to merge across vma->vm_userfaultfd_ctx	2015-09-04 16:54:41 -07:00
mm_init.c	mm: meminit: remove mminit_verify_page_links	2015-06-30 19:44:56 -07:00
mmap.c	mm, dax: VMA with vm_ops->pfn_mkwrite wants to be write-notified	2015-09-22 15:09:53 -07:00
mmu_context.c
mmu_notifier.c	mmu-notifier: add clear_young callback	2015-09-10 13:29:01 -07:00
mmzone.c
mprotect.c	userfaultfd: teach vma_merge to merge across vma->vm_userfaultfd_ctx	2015-09-04 16:54:41 -07:00
mremap.c	mremap: simplify the "overlap" check in mremap_to()	2015-09-04 16:54:41 -07:00
msync.c
nobootmem.c	mm: page_alloc: pass PFN to __free_pages_bootmem	2015-06-30 19:44:55 -07:00
nommu.c	mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()	2015-09-10 13:29:01 -07:00
oom_kill.c	mm, oom: remove unnecessary variable	2015-09-08 15:35:28 -07:00
page_alloc.c	Merge branch 'akpm' (patches from Andrew)	2015-09-08 17:52:23 -07:00
page_counter.c
page_ext.c	mm: introduce idle page tracking	2015-09-10 13:29:01 -07:00
page_idle.c	mm: introduce idle page tracking	2015-09-10 13:29:01 -07:00
page_io.c	fs: use helper bio_add_page() instead of open coding on bi_io_vec	2015-08-13 12:32:00 -06:00
page_isolation.c	mm, page_isolation: make set/unset_migratetype_isolate() file-local	2015-09-08 15:35:28 -07:00
page_owner.c	mm/page_owner: set correct gfp_mask on page_owner	2015-07-17 16:39:54 -07:00
page-writeback.c	writeback: bdi_writeback iteration must not skip dying ones	2015-10-12 10:31:12 -06:00
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c	percpu: clean up of schunk->map[] assignment in pcpu_setup_first_chunk	2015-07-21 11:31:00 -04:00
pgtable-generic.c	mm: clarify that the function operates on hugepage pte	2015-06-24 17:49:44 -07:00
process_vm_access.c
quicklist.c
readahead.c	writeback: implement and use inode_congested()	2015-06-02 08:33:35 -06:00
rmap.c	mm: introduce idle page tracking	2015-09-10 13:29:01 -07:00
shmem.c	shmem: recalculate file inode when fstat	2015-09-08 15:35:28 -07:00
slab_common.c	memcg: export struct mem_cgroup	2015-09-08 15:35:28 -07:00
slab.c	mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)	2015-10-01 21:42:35 -04:00
slab.h	mm/slab.h: fix argument order in cache_from_obj's error message	2015-09-04 16:54:41 -07:00
slob.c	mm: rename alloc_pages_exact_node() to __alloc_pages_node()	2015-09-08 15:35:28 -07:00
slub.c	mm: rename alloc_pages_exact_node() to __alloc_pages_node()	2015-09-08 15:35:28 -07:00
sparse-vmemmap.c
sparse.c
swap_cgroup.c
swap_state.c	mm: swap: zswap: maybe_preload & refactoring	2015-09-08 15:35:28 -07:00
swap.c	mm: introduce idle page tracking	2015-09-10 13:29:01 -07:00
swapfile.c	mm: /proc/pid/smaps:: show proportional swap share of the mapping	2015-09-08 15:35:28 -07:00
truncate.c	memcg: add per cgroup dirty page accounting	2015-06-02 08:33:33 -06:00
userfaultfd.c	userfaultfd: avoid mmap_sem read recursion in mcopy_atomic	2015-09-04 16:54:41 -07:00
util.c	mm: uninline and cleanup page-mapping related helpers	2015-04-15 16:35:19 -07:00
vmacache.c
vmalloc.c	mm/vmalloc: get rid of dirty bitmap inside vmap_block structure	2015-04-15 16:35:18 -07:00
vmpressure.c
vmscan.c	vmscan: fix sane_reclaim helper for legacy memcg	2015-09-22 15:09:53 -07:00
vmstat.c
workingset.c
zbud.c	mm: zbud: constify the zbud_ops	2015-09-08 15:35:28 -07:00
zpool.c	zpool: add zpool_has_pool()	2015-09-10 13:29:01 -07:00
zsmalloc.c	mm: zpool: constify the zpool_ops	2015-09-08 15:35:28 -07:00
zswap.c	zswap: change zpool/compressor at runtime	2015-09-10 13:29:01 -07:00